"uuid","repository link","title","author","contributor","publication year","abstract","subject topic","language","publication type","publisher","isbn","issn","patent","patent status","bibliographic note","access restriction","embargo date","faculty","department","research group","programme","project","coordinates"
"uuid:79f41801-69d9-4359-9b1e-4ad53efe9948","http://resolver.tudelft.nl/uuid:79f41801-69d9-4359-9b1e-4ad53efe9948","Author Correction: Origin of fast charging in hard carbon anodes (Nature Energy, (2024), 10.1038/s41560-023-01414-5)","Vasileiadis, A. (TU Delft RST/Storage of Electrochemical Energy); Zhou, Q. (TU Delft Design Conceptualization and Communication; Chinese Academy of Sciences); Lu, Yaxiang (Chinese Academy of Sciences); Li, Y. (TU Delft Aerospace Engineering/International Space University; Chinese Academy of Sciences; University of Chinese Academy of Sciences); Ombrini, P. (TU Delft RST/Storage of Electrochemical Energy); Chen, Z. (TU Delft Electronic Instrumentation; Chinese Academy of Sciences; University of Chinese Academy of Sciences); van der Jagt, R. (TU Delft RST/Storage of Electrochemical Energy); Ganapathy, S. (TU Delft RID/TS/Instrumenten groep); Wagemaker, M. (TU Delft RST/Storage of Electrochemical Energy)","","2024","Correction to: Nature Energy, published online 3 January 2024. In the version of this article initially published, lithium (green, “Li”) and sodium (purple, “Na”) color key labels in Fig. 3a,d,e were interchanged and are now amended in the HTML and PDF versions of the article.","","en","journal article","","","","","","Corrigendum voor DOI 10.1038/s41560-023-01414-5","","2024-07-03","","Aerospace Engineering/International Space University","RST/Storage of Electrochemical Energy","","",""
"uuid:0fddf122-d78d-4365-8e86-2cab32ade2f7","http://resolver.tudelft.nl/uuid:0fddf122-d78d-4365-8e86-2cab32ade2f7","Towards a pattern language for green space design in high density urban developments","Zhou, S. (TU Delft Urban Design); Nijhuis, S. (TU Delft Landscape Architecture); Dijkstra, R.J. (TU Delft Urban Design)","","2024","In the inevitable high-density urbanization process, existing urban green space (UGS) design approaches are ineffective in creating more green areas and combining multidisciplinary design principles to provide balanced sets of ecosystem services (ESs). This paper proposes a systematic framework for UGS design in the context of high-density urban development, results in spatial patterns, a pattern language, that combines specific design principles with a wide range of complementary ESs suitable for high-density environments. Such design approach can create more possibilities for UGS provisioning, deal with the complexity in high-density contexts, and provides consistency at different scale for UGS designs.","Green space design; high-density urban environment; ecosystem services; pattern language","en","journal article","","","","","","","","","","","Urban Design","","",""
"uuid:640c0f3e-60c4-4736-ae08-352bef953637","http://resolver.tudelft.nl/uuid:640c0f3e-60c4-4736-ae08-352bef953637","On the post-impact fatigue behavior and theoretical life prediction of CF/PEEK-titanium hybrid laminates using an energy dissipation approach","Ji, C. (TU Delft Structural Integrity & Composites; Harbin Institute of Technology); Hu, Jiqiang (Harbin Institute of Technology); Alderliesten, R.C. (TU Delft Structural Integrity & Composites); Yang, Jinchuan (Harbin Institute of Technology); Zhou, Zhengong (Harbin Institute of Technology); Sun, Yuguo (Harbin Institute of Technology); Wang, Bing (Harbin Institute of Technology)","","2024","This paper aims to illustrate the effect of the impact damage on fatigue behavior of CF/PEEK-titanium hybrid laminates. To achieve this end, a fatigue life model was proposed to predict the S–N curves of the laminates at various initial impact energy levels and stress ratios based on the energy dissipation approach. The energy dissipation behavior of the laminates during fatigue loading under different experimental conditions was analyzed through a large amount of post-impact fatigue tests, and the correlation between the initial impact damage and the total fatigue dissipation energy was determined. The full-field axial strain distribution of the titanium layer on the impacted side of the laminate was characterized in terms of initial impact energy level and maximum stress using digital image correlation, and then the post-impact fatigue failure mechanism of CF/PEEK-Ti hybrid laminates was summarized. Finally, the validity of the proposed model was verified by fatigue tests under other conditions of stress ratio and impact energy level. It is worth mentioning that the proposed model is also applicable to other types of FMLs, and can accurately predict the residual fatigue life of laminates after impact with only one set of S–N curve data.","Energy dissipation approach; Fiber metal laminates; Life prediction; Post-impact fatigue behavior","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-06-03","","","Structural Integrity & Composites","","",""
"uuid:accf47a3-38dd-4b1e-827e-b5ec20991b39","http://resolver.tudelft.nl/uuid:accf47a3-38dd-4b1e-827e-b5ec20991b39","An analytical framework for the best–worst method","Wu, W. (TU Delft Transport and Logistics; Anhui University; Southeast University); Liu, Xinwang (Southeast University); Zhou, Ligang (Anhui University); Qin, Jindong (Wuhan University of Technology); Rezaei, J. (TU Delft Transport and Logistics)","","2024","Since the development of the best–worst method (BWM) in 2015, it has become a popular research focus in multi-criteria decision-making. The original optimization problem of the BWM is a nonlinear min–max model that can lead to multiple optimal solutions, while the linear model of the BWM produces a unique solution. The two models need to be solved by optimization software packages. In addition, although the linear model of the BWM can obtain a unique solution, it produces different feasible regions than the nonlinear model of the BWM, and it changes the objective function. This study aims to solve the nonlinear model of the BWM mathematically to obtain the analytical forms of the optimal solutions. First, we transform the original nonlinear model of BWM into an equivalent optimization model driven by the optimally modified comparison vectors. The equivalent BWM provides a solid basis for computing the analytical solutions. Second, for not-fully consistent pairwise comparison systems, we strictly prove that there is only one unique optimal solution with three criteria, and there might be multiple optimal solutions with more than three criteria. We further develop the analytical forms of these unique and multiple optimal solutions and the optimal interval weights. Third, we develop a secondary objective function to select a unique solution for the BWM. The secondary objective function retains all the characteristics of the original nonlinear model of the BWM, and we find the unique solution analytically. Finally, some numerical examples are examined, and a comparative analysis is performed to demonstrate the effectiveness of our analytical solution approach.","Analytical solutions; Best–worst method (BWM); Multi-criteria decision-making; Multiple optimal solutions","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-04-25","","","Transport and Logistics","","",""
"uuid:9b12e05f-859d-4233-ae02-9fe762741a1e","http://resolver.tudelft.nl/uuid:9b12e05f-859d-4233-ae02-9fe762741a1e","Giant magnetocaloric effect for (Mn, Fe, V)2(P, Si) alloys with low hysteresis","Lai, J. (TU Delft Electrical Engineering, Mathematics and Computer Science; South China Normal University); Huang, B. (TU Delft RST/Fundamental Aspects of Materials and Energy); You, X. (TU Delft RST/Fundamental Aspects of Materials and Energy); Maschek, M. (TU Delft RST/Fundamental Aspects of Materials and Energy); Zhou, Guofu (South China Normal University); van Dijk, N.H. (TU Delft RST/Fundamental Aspects of Materials and Energy); Brück, E.H. (TU Delft RST/Fundamental Aspects of Materials and Energy)","","2024","The Fe2P type Mn–Fe–P–Si alloys exhibit a giant magneto-elastic first-order transition, but the large hysteresis limits their performance. Crystal structure evolution and magnetocaloric performance were investigated by varying the Mn and Fe contents at a constant V substitution of 0.02 in Fe2P-type (Mn1.17-xFe0.73-yV0.02) (P0.5Si0.5) (where x + y = 0.02). The V substitution of Fe content shows a larger reduction of hysteresis compared with the same substitution amount of Mn content. During magnetoelastic phase transition, V-substitution reduces the volume change and the volumetric stresses, providing a superior mechanical stability. Compound with the V substitution of Fe (y = 0.02) shows the best magnetocaloric effect with a low thermal hysteresis of 0.6 K. Our developed Mn1.17-xFe0.73-yV0.02P0.5Si0.5 alloys are excellent materials for room-temperature magnetic heat-pumping applications by using a permanent magnet.","(Mn,Fe)(P,Si) alloy; Adiabatic temperature change; Crystal structure evolution; Hysteresis; Isothermal entropy change; Magnetocaloric effect","en","journal article","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:13c09c8b-40b2-4f3e-9f26-5c47ca308010","http://resolver.tudelft.nl/uuid:13c09c8b-40b2-4f3e-9f26-5c47ca308010","Asymmetric α-benzylation of cyclic ketones enabled by concurrent chemical aldol condensation and biocatalytic reduction","Liu, Yunting (Hebei University of Technology); Ma, Teng (Hebei University of Technology); Guo, Zhongxu (Hebei University of Technology); Zhou, Liya (Hebei University of Technology); Liu, Guanhua (Hebei University of Technology); He, Ying (Hebei University of Technology); Ma, Li (Hebei University of Technology); Gao, Jing (Hebei University of Technology); Hollmann, F. (TU Delft BT/Biocatalysis)","","2024","Chemoenzymatic cascade catalysis has emerged as a revolutionary tool for streamlining traditional retrosynthetic disconnections, creating new possibilities for the asymmetric synthesis of valuable chiral compounds. Here we construct a one-pot concurrent chemoenzymatic cascade by integrating organobismuth-catalyzed aldol condensation with ene-reductase (ER)-catalyzed enantioselective reduction, enabling the formal asymmetric α-benzylation of cyclic ketones. To achieve this, we develop a pair of enantiocomplementary ERs capable of reducing α-arylidene cyclic ketones, lactams, and lactones. Our engineered mutants exhibit significantly higher activity, up to 37-fold, and broader substrate specificity compared to the parent enzyme. The key to success is due to the well-tuned hydride attack distance/angle and, more importantly, to the synergistic proton-delivery triade of Tyr28-Tyr69-Tyr169. Molecular docking and density functional theory (DFT) studies provide important insights into the bioreduction mechanisms. Furthermore, we demonstrate the synthetic utility of the best mutants in the asymmetric synthesis of several key chiral synthons.","","en","journal article","","","","","","","","","","","BT/Biocatalysis","","",""
"uuid:e5bdaf21-e7ab-4694-abe2-e57f7412360a","http://resolver.tudelft.nl/uuid:e5bdaf21-e7ab-4694-abe2-e57f7412360a","Origin of fast charging in hard carbon anodes","Vasileiadis, A. (TU Delft RST/Storage of Electrochemical Energy); Zhou, Quan (Chinese Academy of Sciences; HiNa Battery Technology, Beijing); Lu, Yaxiang (Chinese Academy of Sciences); Li, Yu (Chinese Academy of Sciences; University of Chinese Academy of Sciences); Ombrini, P. (TU Delft RST/Storage of Electrochemical Energy); Chen, Zhao (Chinese Academy of Sciences; University of Chinese Academy of Sciences); van der Jagt, R. (TU Delft RST/Storage of Electrochemical Energy); Ganapathy, S. (TU Delft RID/TS/Instrumenten groep); Wagemaker, M. (TU Delft RST/Storage of Electrochemical Energy)","","2024","Transport electrification and grid storage hinge largely on fast-charging capabilities of Li- and Na-ion batteries, but anodes such as graphite with plating issues drive the scientific focus towards anodes with slopped storage potentials. Here we report fast charging of ampere-hour-level full Na-ion batteries within about 9 minutes for continuous 3,000 cycles based on hard carbon anodes. These anodes, in addition to displaying a sloped storage voltage, provide capacity at a nearly constant voltage just above the plating potential, without observing Na-metal plating under high areal capacity. Comparing the electrochemical behaviour of Li and Na in hard carbon through experimental and computational techniques, a unified storage mechanism relying on the dimensions of wedge nanopores and drawing parallels with underpotential deposition for metals is brought forward, providing a rational guide for achieving fast storage in hard carbon anodes.","","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-07-03","","","RST/Storage of Electrochemical Energy","","",""
"uuid:1748f6c4-08e2-4124-aee3-68398205bfaf","http://resolver.tudelft.nl/uuid:1748f6c4-08e2-4124-aee3-68398205bfaf","Tunable visible emission and persistent luminescence of BaGa2O4:Cu2+","Wang, Lei (Hefei University of Technology); Zhao, Ning (Hefei University of Technology); Zhu, Changrui (Hefei University of Technology); Chen, Lei (Hefei University of Technology); Jiang, Yang (Hefei University of Technology); Zhou, Rulong (Hefei University of Technology); Liu, Yanfang (Hefei University of Technology); Qu, Bingyan (Hefei University of Technology); Hintzen, H.T.J.M. (TU Delft RST/Luminescence Materials)","","2024","In the field of solid-state luminescence, Cu2+ has long been widely acknowledged for its capacity to emit infrared light. However, the occurrence of visible emission from Cu2+ ions had been infrequently observed and reported. In this study, we made an intriguing discovery by examining the behavior of Cu2+ within an irregular coordination environment of Ba in BaGa2O4. When excited by UV light, Cu2+ unexpectedly gave a vibrant yellow–red emission, covering a wavelength range spanning from 500 to 750 nm. More noteworthy, by simply manipulating the excitation wavelength or adjusting the temperature, the peak wavelength of the emission could be effectively tuned from approximately 600 to 660 nm, which could be attributed to the luminescence nature of the charge transfer (CT) between O2− and Cu2+. Moreover, the phosphor material displayed a remarkable persistent luminescence (PerL) lasting up to 12 h after UV light excitation. Through thermoluminescence (TL) measurements and first-principle calculations, we found that the intrinsic defects, such as vacancies of oxygen and gallium (VO and VGa″), played important roles for the PerL phenomena. These findings highlighted the exceptional tunability and PerL properties of BaGa2O4:Cu2+. Our study provided a new potential guideline for the design of Cu2+-activated phosphors in visible region, and opened up new avenues for the research in related functional luminescence materials.","Cu luminescence; Mechanism; Persistent luminescence; Phosphors; Tunable emission","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-09-01","","","RST/Luminescence Materials","","",""
"uuid:7ab42167-5443-44e5-9d78-df162057e571","http://resolver.tudelft.nl/uuid:7ab42167-5443-44e5-9d78-df162057e571","Precursor- and waste-free synthesis of spark-ablated nanoparticles with enhanced photocatalytic activity and stability towards airborne organic pollutant degradation","Drdova, Sarka (ETH Zürich; Swiss Federal Laboratories for Materials Science and Technology (Empa)); Gao, Min (ETH Zürich; Swiss Federal Laboratories for Materials Science and Technology (Empa)); Sambalova, Olga (Swiss Federal Laboratories for Materials Science and Technology (Empa)); Pauer, Robin (Swiss Federal Laboratories for Materials Science and Technology (Empa)); Zhou, Zhouping (Student TU Delft); Dimitriadou, Sofia (VSPARTICLE); Schmidt-Ott, A. (TU Delft ChemE/Materials for Energy Conversion and Storage; VSPARTICLE); Wang, J. (ETH Zürich; Swiss Federal Laboratories for Materials Science and Technology (Empa))","","2024","Photocatalyst synthesis typically involves multiple steps, expensive precursors, and solvents. In contrast, spark ablation offers a simple process of electrical discharges in a gap between two electrodes made from a desirable material. This enables a precursor- and waste-free generation of pure metal oxide nanoparticles or mixtures of various compositions. This study presents a two-step method for the production of photocatalytic filters with deposited airborne MnOx, TiO2, and ZnO nanoparticles using spark ablation and calcination processes. The resulting MnOx and TiO2 filters demonstrated almost twice the activity with outstanding performance stability, as compared to sol-gel MnO2 and commercial TiO2. The introduced method is not only simple, precursor- and waste-free, and leads to superior performance for the case studied, but it also has future potential due to its versatility. It can easily produce mixed and doped materials with further improved properties, making it an interesting avenue for future research.","","en","journal article","","","","","","","","","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:cc6e2ae1-2500-4339-ab9c-bcb8ba8eb9ce","http://resolver.tudelft.nl/uuid:cc6e2ae1-2500-4339-ab9c-bcb8ba8eb9ce","Integrated CO2 capture and reduction catalysis: Role of γ-Al2O3 support, unique state of potassium and synergy with copper","Pinto, D. (TU Delft ChemE/Catalysis Engineering); Minorello, S. (TU Delft ChemE/Catalysis Engineering); Zhou, Zhouping (Student TU Delft); Urakawa, A. (TU Delft ChemE/Catalysis Engineering)","","2024","Carbon dioxide capture and reduction (CCR) process emerges as an efficient catalytic strategy for CO2 capture and conversion to valuable chemicals. K-promoted Cu/Al2O3 catalysts exhibited promising CO2 capture efficiency and highly selective conversion to syngas (CO + H2). The dynamic nature of the Cu-K system at reaction conditions complicates the identification of the catalytically active phase and surface sites. The present work aims at more precise understanding of the roles of the potassium and copper and the contribution of the metal oxide support. While γ-Al2O3 guarantees high dispersion and destabilisation of the potassium phase, potassium and copper act synergistically to remove CO2 from diluted streams and promote fast regeneration of the active phase for CO2 capture releasing CO while passing H2. A temperature of 350℃ is found necessary to activate H2 dissociation and generate the active sites for CO2 capture. The effects of synthesis parameters on the CCR activity are also described by combination of ex-situ characterisation of the materials and catalytic testing.","Aluminium oxide; Carbon capture and utilisation; Carbon dioxide; CO capture and reduction; Copper catalysts; Heterogeneous catalysis; Potassium; Solid CO sorbents","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-08-07","","","ChemE/Catalysis Engineering","","",""
"uuid:ddb484e7-190d-4c98-8ede-2ab732c7f299","http://resolver.tudelft.nl/uuid:ddb484e7-190d-4c98-8ede-2ab732c7f299","A multi-step fast charging-based battery capacity estimation framework of real-world electric vehicles","Zhang, D. (TU Delft DC systems, Energy conversion & Storage; Beijing Institute of Technology); Wang, Zhenpo (Beijing Institute of Technology); Liu, Peng (Beijing Institute of Technology); She, Chengqi (Hunan University of Science and Technology); Wang, Qiushi (Beijing Institute of Technology); Zhou, Litao (Beijing Institute of Technology); Qin, Z. (TU Delft DC systems, Energy conversion & Storage)","","2024","Accurately evaluating battery degradation is not only crucial for ensuring the safe and reliable operation of electric vehicles (EVs) but also fundamental for their intelligent management and maximum utilization. However, the non-linearity, non-measurability, and multi-stress coupled operating conditions have posed significant challenges for battery health prediction. This paper proposes a battery capacity estimation framework based on real-world operating data. Firstly, a comprehensive feature pool is constructed from the direct external features extracted during multi-step fast charging processes and the quantitative representation of operating conditions. Subsequently, a two-step feature engineering is introduced to select the most relevant features and eliminate the interference components. The battery capacity estimation framework is then implemented using machine learning methods. Validation results demonstrate that the proposed framework achieves superior estimation accuracy with lower computational expense compared to the modelling process without feature engineering. The MAPE and RMSE reach 1.18% and 1.98 Ah, respectively, representing reductions in errors of up to 8.53% and 11.21%. Collectively, the proposed framework paves the foundation for online health prognostics of batteries under practical operating conditions.","Lithium-ion battery; Capacity estimation; Multi-step fast charging; Machine learning; Real-world data","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-08-22","","","DC systems, Energy conversion & Storage","","",""
"uuid:905164f0-b023-4606-9769-1f598907fa43","http://resolver.tudelft.nl/uuid:905164f0-b023-4606-9769-1f598907fa43","Fast-charge high-voltage layered cathodes for sodium-ion batteries","Wang, Q. (TU Delft RST/Storage of Electrochemical Energy); Zhou, Dong (Helmholtz-Zentrum Berlin); Zhao, C. (TU Delft RST/Storage of Electrochemical Energy); Wang, Jianlin (Chinese Academy of Sciences); Guo, Hao (China Institute of Atomic Energy); Wang, Liguang (Zhejiang University); Yao, Zhenpeng (Shanghai Jiao Tong University); Lu, Jun (Zhejiang University); Wagemaker, M. (TU Delft RST/Storage of Electrochemical Energy)","","2024","Sodium-ion batteries have not only garnered substantial attention for grid-scale energy storage owing to the higher abundance of sodium compared with lithium, but also present the possibility of fast charging because of the inherently higher sodium-ion mobility. However, it remains a phenomenal challenge to achieve a combination of these merits, given the complex structural chemistry of sodium-ion oxide materials. Here we show that O3-type sodium-ion layered cathodes (for example, Na5/6Li2/27Ni8/27Mn11/27Ti6/27O2) have the potential to attain high power density, high energy density (260 Wh kg−1 at the electrode level) and long cycle life (capacity retention of 80% over 700 cycles in full cells). The design involves introduction of characteristic P3-structural motifs into an O3-type framework that serves to promote sodium-ion diffusivity and address detrimental transition metal migration and phase transition at a high state of charge. This study provides a principle for the rational design of sodium-ion layered oxide electrodes and advances the understanding of the composition–structure–property relationships of oxide cathode materials.","","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-08-15","","","RST/Storage of Electrochemical Energy","","",""
"uuid:259572c1-f79a-4351-87d3-02efdbd20ee8","http://resolver.tudelft.nl/uuid:259572c1-f79a-4351-87d3-02efdbd20ee8","Kirkendall effect-induced uniform stress distribution stabilizes nickel-rich layered oxide cathodes","Gao, Ziyao (Tsinghua University); Zhao, C. (Tsinghua University); Zhou, Kai (Tsinghua University); Wu, Junru (Tsinghua University); Tian, Yao (Tsinghua University); Deng, Xianming (Tsinghua University); Zhang, Lihan (Tsinghua University); Lin, Kui (Tsinghua University); Wagemaker, M. (TU Delft RST/Storage of Electrochemical Energy)","","2024","Nickel-rich layered oxide cathodes promise ultrahigh energy density but is plagued by the mechanical failure of the secondary particle upon (de)lithiation. Existing approaches for alleviating the structural degradation could retard pulverization, yet fail to tune the stress distribution and root out the formation of cracks. Herein, we report a unique strategy to uniformize the stress distribution in secondary particle via Kirkendall effect to stabilize the core region during electrochemical cycling. Exotic metal/metalloid oxides (such as Al2O3 or SiO2) is introduced as the heterogeneous nucleation seeds for the preferential growth of the precursor. The calcination treatment afterwards generates a dopant-rich interior structure with central Kirkendall void, due to the different diffusivity between the exotic element and nickel atom. The resulting cathode material exhibits superior structural and electrochemical reversibility, thus contributing to a high specific energy density (based on cathode) of 660 Wh kg−1 after 500 cycles with a retention rate of 86%. This study suggests that uniformizing stress distribution represents a promising pathway to tackle the structural instability facing nickel-rich layered oxide cathodes.","","en","journal article","","","","","","","","","","","RST/Storage of Electrochemical Energy","","",""
"uuid:a097ae29-f9c3-4629-87f0-49c037cdec52","http://resolver.tudelft.nl/uuid:a097ae29-f9c3-4629-87f0-49c037cdec52","From Short Circuit to Completed Circuit: Conductive Hydrogel Facilitating Oral Wound Healing","Zhou, Qiangqiang (Fudan University); Dai, Hanqing (Fudan University); Yan, Yukun (Fudan University); Qin, Zhiming (Fudan University); Zhou, Mengqi (Fudan University); Zhang, Wanlu (Fudan University); Zhang, Kouchi (TU Delft Electronic Components, Technology and Materials); Guo, Ruiqian (Fudan University); Wei, X. (Fudan University)","","2024","The primary challenges posed by oral mucosal diseases are their high incidence and the difficulty in managing symptoms. Inspired by the ability of bioelectricity to activate cells, accelerate metabolism, and enhance immunity, a conductive polyacrylamide/sodium alginate crosslinked hydrogel composite containing reduced graphene oxide (PAA-SA@rGO) is developed. This composite possesses antibacterial, anti-inflammatory, and antioxidant properties, serving as a bridge to turn the “short circuit” of the injured site into a “completed circuit,” thereby prompting fibroblasts in proximity to the wound site to secrete growth factors and expedite tissue regeneration. Simultaneously, the PAA-SA@rGO hydrogel effectively seals wounds to form a barrier, exhibits antibacterial and anti-inflammatory properties, and prevents foreign bacterial invasion. As the electric field of the wound is rebuilt and repaired by the PAA-SA@rGO hydrogel, a 5 × 5 mm2 wound in the full-thickness buccal mucosa of rats can be expeditiously mended within mere 7 days. The theoretical calculations indicate that the PAA-SA@rGO hydrogel can aggregate and express SOX2, PITX1, and PITX2 at the wound site, which has a promoting effect on rapid wound healing. Importantly, this PAA-SA@rGO hydrogel has a fast curative effect and only needs to be applied for the first three days, which significantly improves patient satisfaction during treatment.","conductive hydrogel; microphysiological electric field; oral mucosal disease; tissue regeneration","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-08-02","","","Electronic Components, Technology and Materials","","",""
"uuid:99e01587-21a2-4d19-87ec-366f3d3b9b8d","http://resolver.tudelft.nl/uuid:99e01587-21a2-4d19-87ec-366f3d3b9b8d","Designing lithium halide solid electrolytes","Wang, Q. (TU Delft RST/Storage of Electrochemical Energy); Zhou, Yunan (Tsinghua University); Wang, Xuelong (Brookhaven National Laboratory); Guo, Hao (China Institute of Atomic Energy); Gong, Shuiping (Shanghai Jiao Tong University); Yao, Zhenpeng (Shanghai Jiao Tong University); Ganapathy, S. (TU Delft RST/Storage of Electrochemical Energy; TU Delft RID/TS/Instrumenten groep); Zhao, C. (TU Delft RST/Storage of Electrochemical Energy); Wagemaker, M. (TU Delft RST/Storage of Electrochemical Energy)","","2024","All-solid-state lithium batteries have attracted widespread attention for next-generation energy storage, potentially providing enhanced safety and cycling stability. The performance of such batteries relies on solid electrolyte materials; hence many structures/phases are being investigated with increasing compositional complexity. Among the various solid electrolytes, lithium halides show promising ionic conductivity and cathode compatibility, however, there are no effective guidelines when moving toward complex compositions that go beyond ab-initio modeling. Here, we show that ionic potential, the ratio of charge number and ion radius, can effectively capture the key interactions within halide materials, making it possible to guide the design of the representative crystal structures. This is demonstrated by the preparation of a family of complex layered halides that combine an enhanced conductivity with a favorable isometric morphology, induced by the high configurational entropy. This work provides insights into the characteristics of complex halide phases and presents a methodology for designing solid materials.","","en","journal article","","","","","","","","","","","RST/Storage of Electrochemical Energy","","",""
"uuid:bc088cea-5a70-459f-8eb9-e5e6d086379b","http://resolver.tudelft.nl/uuid:bc088cea-5a70-459f-8eb9-e5e6d086379b","Towards sustainable groundwater development with effective measures under future climate change in Beijing Plain, China","Liu, S. (TU Delft Water Resources; IHE Delft Institute for Water Education); Zhou, Yangxiao (IHE Delft Institute for Water Education; Hebei University); Eiman, Fatima (IHE Delft Institute for Water Education); McClain, M.E. (TU Delft Water Resources; IHE Delft Institute for Water Education); Wang, Xu sheng (China University of Geosciences)","","2024","To cope with the groundwater depletion problem and achieve sustainable groundwater development, groundwater conservation measures and managed aquifer recharge (MAR) have been implemented worldwide. However, knowledge gaps exit how does the aquifer system respond to these interventions differently and if these interventions are adequate to lead to long-term sustainable groundwater development under future climate change. In Beijing Plain, two measures have been implemented: reduction of groundwater abstraction by substituting groundwater abstraction with transferred surface water and implementation of managed aquifer recharge (MAR) in two major rivers. This study aims to assess how do the shallow and deep aquifers respond to these measures and if these measures can lead to long-term sustainable groundwater development in Beijing Plain under future climate change. A 3-D transient groundwater flow model was calibrated and used to simulate groundwater level and budget changes from 2021 to 2050. The monthly groundwater recharge was estimated using the projected monthly precipitation from three downscaled regional climate models under two scenarios (RCP4.5 and RCP8.5). The results show that declines in groundwater head and storage can be reversed with the combined two measures, thereby contributing to achieve sustainable groundwater development. The reduction of abstractions is a deciding measure to reverse the trend of groundwater depletion, especially in the deep confined aquifers, while large scale MAR schemes can restore the cones of depressions in shallow aquifers and maintain the groundwater abstraction. Climate variation has large impacts on groundwater resources, especially, consecutive dry years can cause rapid groundwater storage depletion. The projected monthly precipitation from 2021 to 2050 is not significantly different from the past. Therefore, the projected future precipitation has minor impacts on groundwater resources in the next 30 years. The findings from the study will support the Beijing municipality to maintain the tight control on groundwater abstraction and to implement large-scale MAR schemes in two rivers. This successful example will encourage managers of other heavily exploited aquifers to take similar measures to achieve sustainable groundwater development.","Beijing Plain; Climate change; Groundwater sustainability; Substitution of abstraction, Managed Aquifer Recharge","en","journal article","","","","","","","","","","","Water Resources","","",""
"uuid:2de10f3f-ef0e-495c-8b2c-3129d9ee35c4","http://resolver.tudelft.nl/uuid:2de10f3f-ef0e-495c-8b2c-3129d9ee35c4","Effect of temperature on dislocation-tuned dielectricity and piezoelectricity in single-crystal BaTiO3","Dietrich, Felix (Technische Universität Darmstadt); Ni, Fan (Technische Universität Darmstadt); Fulanović, Lovro (Technische Universität Darmstadt); Zhou, Xiandong (Sichuan University); Isaia, Daniel (Technische Universität Darmstadt); Braga Groszewicz, P. (TU Delft RST/Storage of Electrochemical Energy); Zhang, Chunlin (Physcience Optoelectronics Co., Ltd, Beijing); Xu, Bai Xiang (Technische Universität Darmstadt); Rödel, Jürgen (Technische Universität Darmstadt)","","2024","The pinning-controlled mobility of ferroelectric/ferroelastic domain walls is an important part of managing polarization switching and determining the final properties of ferroelectric and piezoelectric materials. Here, we assess the impact of temperature on dislocation-induced domain wall pinning as well as on dislocation-tuned dielectric and piezoelectric response in barium titanate single crystals. Our solid-state nuclear magnetic resonance spectroscopy results indicate that the entire sample exclusively permits in-plane domains, with their distribution remaining insensitive to temperature changes below the Curie temperature (TC). The domain wall pinning field monotonically decreases with increasing temperature up to TC, as evidenced by a combination of experimental observations and phase-field simulations. Our work highlights the promising potential of dislocation engineering in controlling domain wall mobility within bulk ferroelectrics.","","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-09-11","","","RST/Storage of Electrochemical Energy","","",""
"uuid:d8cc86d0-4c6b-481c-baed-fae5b285d72c","http://resolver.tudelft.nl/uuid:d8cc86d0-4c6b-481c-baed-fae5b285d72c","Astral Body: A Virtual Reality Game for Body Ownership Investigation","Zhou, Yimin (Student TU Delft); Gillavry, Merlijn Mac (Student TU Delft); Yang, Pengzhi (Student TU Delft); Xu, Zihao (Student TU Delft); Zhang, Baitian (Student TU Delft); Bidarra, Rafael (TU Delft Computer Graphics and Visualisation)","Dondio, Pierpaolo (editor); Rocha, Mariana (editor); Brennan, Attracta (editor); Schönbohm, Avo (editor); de Rosa, Francesca (editor); Koskinen, Antti (editor); Bellotti, Francesco (editor)","2024","As one of the most disruptive human-computer interaction techniques, Virtual Reality (VR) provides a novel way to examine human movements, e.g. when investigating Body Ownership (BO) in the field of cognitive sciences, especially when the visual output diverges from real-world actions. Previous research in BO uses questionnaires and brain imaging, where the former is a highly subjective metric, and the latter is very costly in time, money, and personnel. To answer the question How can a VR serious game help overcome current challenges of BO assessment?, we designed Astral Body, a VR game that helps cognitive science researchers assess people’s level of BO. In the game, players are asked to grab ‘flying collectibles’ coming from a portal in space. Researchers can inject different types and levels of asynchrony into the arms of the visualized avatar, thus affecting the players’ BO experience and perception. Players, in turn, can also report whenever they perceive possible mismatched avatar behavior. In addition, researchers can analyze player data, including looking for unconscious responses, e.g. small adjustments in physical movements to mitigate injected asynchrony. Preliminary results from playtesting and qualitative analysis of Astral Bodyindicate that a VR game can effectively help researchers investigate BO phenomena.","Body ownership; Control asynchrony; Virtual reality","en","conference paper","Springer","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-06-03","","","Computer Graphics and Visualisation","","",""
"uuid:328d3299-e8f0-42d8-9e72-d983e197d95e","http://resolver.tudelft.nl/uuid:328d3299-e8f0-42d8-9e72-d983e197d95e","Sub-seasonal soil moisture anomaly forecasting using combinations of deep learning, based on the reanalysis soil moisture records","Wang, X. (Chongqing Jiaotong University; Hohai University); Corzo, Gerald (IHE Delft Institute for Water Education); Lü, Haishen (Hohai University); Zhou, Shiliang (Chongqing Jiaotong University); Mao, K. (TU Delft Physical and Space Geodesy); Zhu, Yonghua (Hohai University); Duarte Prieto, F.S. (TU Delft Water Resources; IHE Delft Institute for Water Education); Liu, Mingwen (Hohai University); Su, Jianbin (Chinese Academy of Sciences)","","2024","Sub-seasonal drought forecasting is crucial for early warning in estimating agricultural production and optimizing irrigation management, as forecasting skills are relatively weak during this period. Soil moisture exhibits stronger persistence compared to other climate system quantities, which makes it especially influential in shaping land-atmosphere feedback, thus supplying a unique insight into drought forecasting. Relying on the soil moisture memory, this study investigates the combination of multiple deep-learning modules for sub-seasonal drought indices hindcast in the Huai River basin of China, using long-term ERA5-Land soil moisture records with a noise-assisted data analysis tool. The inter-compared deep-learning models include a hybrid model and a committee machine framework. The results show that the performance of the committee machine framework can be improved with the help of series decomposition and the forecasting skill is not impaired with the lead time increases. Overall, this study highlights the potential of combining deep-learning models with soil moisture memory analysis to improve sub-seasonal drought forecasting.","Committee model; Deep learning; Drought forecasting; Noise-assisted tool; Reanalysis soil moisture","en","journal article","","","","","","","","","","","Physical and Space Geodesy","","",""
"uuid:ac0ab01e-8d77-40e0-a304-b5497baf29ba","http://resolver.tudelft.nl/uuid:ac0ab01e-8d77-40e0-a304-b5497baf29ba","Power Disequilibrium Suppression in Bipolar DC Distribution Grids By Using A Series-Parallel Power Flow Controller","Liao, Jianquan (Sichuan University); Zhou, Niancheng (Chongqing University); Qin, Z. (TU Delft DC systems, Energy conversion & Storage); Wang, Qianggang (Chongqing University); Bauer, P. (TU Delft DC systems, Energy conversion & Storage)","","2023","The unbalanced power between positive and negative poles in a bipolar DC distribution network (DC-DN) generates an unbalanced current at the neutral line, which enlarges the power losses of the system and the voltage deviation of DC loads. An unbalanced power suppression strategy based on a series-parallel power flow controller (SP-PFC) is proposed in this paper. The SP-PFC is adopted as the interconnection between two different DC-DNs. The topology and operating modes of SP-PFC are analyzed. Subsequently, SP-PFC output voltage and line current expressions under constant power control are derived. The nonlinear relationship between the output voltage and line current is linearized at the operating point. On this basis, the influences of unbalanced load and receiving-end voltage on the SP-PFC are investigated. A small-signal model of bipolar DC-DN containing an SP-PFC is established, and the system stability is analyzed. A simulation model of the bipolar DC distribution network containing an SP-PFC is built up in MATLAB/Simulink, and the effectiveness of the SP-PFC in the suppression of unbalanced power is verified.","Bipolar DC distribution network; unbalanced power; power flow controller; constant power control","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-09-01","","","DC systems, Energy conversion & Storage","","",""
"uuid:41d54d45-250a-4cfb-b5b5-4b129994adb2","http://resolver.tudelft.nl/uuid:41d54d45-250a-4cfb-b5b5-4b129994adb2","Integrated Sensing and Communication in UAV Swarms for Cooperative Multiple Targets Tracking","Zhou, Longyu (University of Electronic Science and Technology of China (UESTC)); Leng, Supeng (University of Electronic Science and Technology of China (UESTC)); Wang, Q. (TU Delft Embedded Systems); Liu, Qiang (University of Electronic Science and Technology of China (UESTC))","","2023","Various interconnected Internet of Things (IoT) devices have emerged, led by the intelligence of the IoT, to realize exceptional interaction with the physical world. In this context, UAV swarm-enabled Multiple Targets Tracking (UAV-MTT), which can sense and track mobile targets for many applications such as hit-and-run, is an appealing topic. Unfortunately, UAVs cannot implement real-time MTT based on the traditional centralized pattern due to the complicated road network environment. It is also challenging to realize low-overhead UAV swarm cooperation in a distributed architecture for the real-time MTT. To address the problem, we propose a cyber-twin-based distributed tracking algorithm to update and optimize a trained digital model for real-time MTT. We then design a distributed cooperative tracking framework to promote MTT performance. In the design, both short-distance and long-distance distributed tracking cooperation manners are first realized with low energy consumption in communication by integrating resources of sensing and communication. Resource integration promotes target sensing efficiency with a highly successful tracking ratio as well. Theoretical derivation proves our algorithmic convergence. Hardware-in-the-loop simulation results demonstrate that our proposed algorithm can remarkably save 65.7% energy consumption in communication compared to other benchmarks while efficiently promoting 20.0% sensing performance.","Integrated sensing and communication; UAV swarm; Target tracking; cyber-twin","en","journal article","","","","","","","","2023-10-05","","","Embedded Systems","","",""
"uuid:72372386-f9c9-40fb-97ac-20ceee628027","http://resolver.tudelft.nl/uuid:72372386-f9c9-40fb-97ac-20ceee628027","Effects of dynamic changes of desiccation cracks on preferential flow: experimental investigation and numerical modeling","Luo, Y. (TU Delft Water Resources; China University of Geosciences); Zhang, Jiaming (China University of Geosciences); Zhou, Zhi (Hubei University Of Economics); Aguilar Lopez, J.P. (TU Delft Hydraulic Structures and Flood Risk); Greco, Roberto (Università degli Studi della Campania “Luigi Vanvitelli”); Bogaard, T.A. (TU Delft Water Resources)","","2023","Preferential flow induced by desiccation cracks (PF-DC) has been proven to be an important hydrological effect that could cause various geotechnical engineering and ecological environment problems. Investigation on the PF-DC remains a great challenge due to the soil shrinking–swelling behavior. This work presents an experimental and numerical study of the PF-DC considering the dynamic changes of desiccation cracks. A soil column test was conducted under wetting–drying cycles to investigate the dynamic changes of desiccation cracks and their hydrological response. The ratios between the crack area and soil matrix area (crack ratio), crack aperture and depth were measured. The soil water content, matrix suction and water drainage were monitored. A new dynamic dual-permeability preferential flow model (DPMDy) was developed, which includes physically consistent functions in describing the variation of both porosity and hydraulic conductivity in crack and matrix domains. Its performance was compared to the single-domain model (SDM) and rigid dual-permeability model (DPM) with fixed crack ratio and hydraulic conductivity. The experimental results showed that the maximum crack ratio and aperture decreased when the evaporation intensity was excessively raised. The self-closure phenomenon of cracks and increased surficial water content was observed during low-evaporation periods. The simulation results showed that the matrix evaporation modeled by the DPMDy is lower than that of the SDM and DPM, but its crack evaporation is the highest. Compared to the DPM, the DPMDy simulated a faster pressure head building-up process in the crack domain and higher water exchange rates from the crack to the matrix domain during rainfall. Using a fixed crack ratio in the DPM, whether it is the maximum or the average value from the experiment data, will overestimate the infiltration fluxes of PF-DC but underestimate its contribution to the matrix domain. In conclusion, the DPMDy better described the underlying physics involving crack evolution and hydrological response with respect to the SDM and DPM. Further improvement of the DPMDy should focus on the hysteresis effect of the soil water retention curve and soil deformation during wetting–drying cycles.","","en","journal article","","","","","","","","","","","Water Resources","","",""
"uuid:2910ea09-5226-4311-9106-31ff7cf6cd14","http://resolver.tudelft.nl/uuid:2910ea09-5226-4311-9106-31ff7cf6cd14","On the use of common random numbers in activity-based travel demand modeling for scenario comparison","Zhou, H. (Universiteit van Amsterdam; TNO); Dorsman, J. L. (Universiteit van Amsterdam); Mandjes, M. (Universiteit van Amsterdam); Snelder, M. (TU Delft Transport and Planning; TNO)","","2023","Activity-based travel demand models provide a high level of detail when modeling complex travel behavior. Since stochastic simulation is used, however, this high level may induce large random fluctuations in the output, necessitating many model reruns to produce reliable output. This may become prohibitive in terms of computation time when comparing travel behavior between multiple scenarios, in which case each scenario requires its own simulation. To alleviate this issue, we study the use of common random numbers, which is a technique that reuses the same random numbers for choices made by travelers between scenarios. This ensures that any observed difference in output across scenarios cannot be attributed to mutual differences in drawn random numbers, eliminating an important source of random fluctuation. We demonstrate by a numerical study that common random numbers can greatly reduce the number of runs needed, and thus also the required computation time, to obtain reliable output.","activity-based modeling; common random numbers; Scenario comparison; travel demand","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-09-22","","","Transport and Planning","","",""
"uuid:a73acffb-9714-49a4-9c20-dd20fd777838","http://resolver.tudelft.nl/uuid:a73acffb-9714-49a4-9c20-dd20fd777838","Experimental Testing and Constitutive Modelling of Pavement Materials","Liu, X. (TU Delft Pavement Engineering); Zhang, Yuqing (Aston University); You, Zhanping (Michigan Technological University); Wang, Linbing (University of Georgia); Zhou, Changhong (Guilin University of Electronic Technology)","","2023","","","en","contribution to periodical","","","","","","","","","","","Pavement Engineering","","",""
"uuid:5a93f427-df88-4734-b7a8-38605cbee71c","http://resolver.tudelft.nl/uuid:5a93f427-df88-4734-b7a8-38605cbee71c","Bandwidth Characterization of c-Si Solar Cells as VLC Receiver under Colored LEDs","Zhou, Y. (TU Delft Photovoltaic Materials and Devices); Ibrahim, Aya (Student TU Delft); Muttillo, M. (TU Delft Photovoltaic Materials and Devices); Manganiello, P. (TU Delft Photovoltaic Materials and Devices); Ziar, H. (TU Delft Photovoltaic Materials and Devices); Isabella, O. (TU Delft Photovoltaic Materials and Devices)","","2023","This paper presents the fundamental study on the relationship between LED light sources and the performance of solar cell as receivers in visible light communication (VLC) links. Here, different colors of LEDs are modulated with a sinusoidal signal, and the bandwidth of the VLC system based on various c-Si PV architectures is characterized at different bias voltages. The preliminary results show that the bandwidth of such VLC system is highly influenced by the bias voltage, where higher bias voltage leads to lower bandwidth. This means that there is a trade-off between energy harvesting and communication performance when solar cells are used as VLC receivers. Meanwhile, we also observed that the bandwidth decreases as the LED irradiance level increases, and the color of LED (currently red and blue LEDs are characterized) does not pose a significant impact on the bandwidth. The highest bandwidth is found at 50 kHz for a VLC system using a 6-in TOPCON solar cell under 100 W/m2 with 100 mV bias voltage.","visible light communication (VLC); solar cells; LED colors; Photovoltatronics","en","conference paper","IEEE","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-02-01","","","Photovoltaic Materials and Devices","","",""
"uuid:e08da0b8-609f-47f7-8d9c-4d1440a99664","http://resolver.tudelft.nl/uuid:e08da0b8-609f-47f7-8d9c-4d1440a99664","Distribution Network Reconfiguration Considering the Impacts of Local Renewable Generation and External Power Grid","Li, H. (Chongqing University of Technology); Lekić, A. (TU Delft Intelligent Electrical Power Grids); Li, Shan (Chongqing University of Technology); Jiang, Dongrong (Chongqing University of Technology); Guo, Qiang (Chongqing University of Technology); Zhou, Lin (Chongqing University)","","2023","The distribution network (DN) reconfiguration is a well-known optimal power flow (OPF) problem. However, with the transition of DN from 'passive' to 'active', new technical challenges arise in DN reconfiguration. This article addresses two key issues in this regard. Firstly, the integration of local renewable generation (LRG) introduces uncertainty into the system-wide power flow of the DN. Secondly, the coupling between DN and the external power grid (EPG) affects the determination of DN root voltage. Consequently, a novel DN reconfiguration approach is proposed in this article. To begin with, an explicit mixed-integer convex OPF model is constructed that incorporates both the EPG and DN sides. Notably, the OPF model embeds the function of local droop control that is provided by LRG. Subsequently, the original OPF model is decomposed, and the distributed optimization methods based on the augmented Lagrangian relaxation are employed. The article comprehensively discusses parallel processing and asynchronous implementation as parts of the distributed optimization procedure. Furthermore, to address the uncertainty related to LRG integration, the extreme scenario method is used to provide a robust decision regarding DN reconfiguration. The application of the extreme scenario method in the distributed OPF model concerning DN reconfiguration is successively developed. Finally, numerical results are presented to demonstrate the acceptable performance of the distributed optimization methods, in terms of optimality and convergence. Also, these are validated that the proposed DN reconfiguration approach exhibits robustness to LRG integration, the system-wide voltage profile is improved, and the active power loss is effectively reduced using the proposed DN reconfiguration approach.","Augmented lagrangian relaxation; distribution network reconfiguration; external power grid (EPG); extreme scenario method; Load flow; local renewable energy (LRG); Mathematical models; Metaheuristics; Optimization; Reactive power; Uncertainty; Voltage","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-02-05","","","Intelligent Electrical Power Grids","","",""
"uuid:b62d473b-618b-48c1-93d0-14c022c8967f","http://resolver.tudelft.nl/uuid:b62d473b-618b-48c1-93d0-14c022c8967f","Deep Learning for Size-Agnostic Inverse Design of Random-Network 3D Printed Mechanical Metamaterials","Pahlavani, H. (TU Delft Biomaterials & Tissue Biomechanics); Tsifoutis-Kazolis, Kostas (Student TU Delft); Cruz Saldivar, M. (TU Delft Biomaterials & Tissue Biomechanics); Mody, Prerak (Leiden University Medical Center); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Mirzaali, Mohammad J. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2023","Practical applications of mechanical metamaterials often involve solving inverse problems aimed at finding microarchitectures that give rise to certain properties. The limited resolution of additive manufacturing techniques often requires solving such inverse problems for specific specimen sizes. Moreover, the candidate microarchitectures should be resistant to fatigue and fracture. Such a multi-objective inverse design problem is formidably difficult to solve but its solution is the key to real-world applications of mechanical metamaterials. Here, a modular approach titled “Deep-DRAM” that combines four decoupled models is proposed, including two deep learning (DL) models, a deep generative model based on conditional variational autoencoders, and direct finite element (FE) simulations. Deep-DRAM integrates these models into a framework capable of finding many solutions to the posed multi-objective inverse design problem based on random-network unit cells. Using an extensive set of simulations as well as experiments performed on 3D printed specimens, it is demonstrate that: 1) the predictions of the DL models are in agreement with FE simulations and experimental observations, 2) an enlarged envelope of achievable elastic properties (e.g., rare combinations of double auxeticity and high stiffness) is realized using the proposed approach, and 3) Deep-DRAM can provide many solutions to the considered multi-objective inverse design problem.","additive manufacturing; deep learning; numerical simulations; random-network mechanical metamaterials; size-agnostic; variational autoencoder","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:b7e4221e-e417-4715-b4bb-f878da5f6874","http://resolver.tudelft.nl/uuid:b7e4221e-e417-4715-b4bb-f878da5f6874","The uncertainty associated with the use of copulas in multivariate analysis","Zhou, C. (TU Delft Water Resources); van Nooijen, R.R.P. (TU Delft Water Resources); Kolechkina, A.G. (TU Delft Team Bart De Schutter); Gargouri, E.F.G. (University of Tunis El Manar); Slama, Fairouz (University of Tunis El Manar); van de Giesen, N.C. (TU Delft Water Resources)","","2023","The dependency structure between hydrological variables is of critical importance to hydrological modelling and forecasting. When a copula capturing that dependence is fitted to a sample, information on the uncertainty of the fit is needed for subsequent hydrological calculations and reasoning. A new method is proposed to report inferential uncertainty in a copula parameter. The method is based on confidence curves constructed with the use of a pseudo maximum likelihood estimator for the copula parameter. The method was tested on synthetic data and then used as a tool in two hydrological examples. The first examines the probability of major floods in two locations on the Rhine River and its tributaries in the same calendar year. In the second example, rainfall–runoff from a karst region in Tunisia was analysed to determine a confidence interval for the delay between precipitation and runoff.","confidence curve; copulas; coverage probability; pseudo maximum likelihood estimator; uncertainty analysis","en","journal article","","","","","","","","","","","Water Resources","","",""
"uuid:dfa43129-6d90-46e4-8f4e-6003f100a584","http://resolver.tudelft.nl/uuid:dfa43129-6d90-46e4-8f4e-6003f100a584","Groyne-Induced Effects on Channel-Shoal Exchange and Saltwater Intrusion in Estuarine Environments","Zhou, Zaiyang (East China Normal University); Ge, Jianzhong (Institute of Eco-Chongming; East China Normal University); van Maren, D.S. (TU Delft Environmental Fluid Mechanics; Deltares; East China Normal University); Kuai, Y. (TU Delft Coastal Engineering); Ding, Pingxing (East China Normal University); Wang, Zhengbing (TU Delft Coastal Engineering; Deltares)","","2023","Existing knowledge about groyne-induced effects is primarily based on riverine or coastal environments where salinity gradients are absent or limited. However, in estuaries, salinity gradients drive physical processes such as longitudinal and lateral residual flows. The effect of groynes is much more complex because they can modulate channel hydrodynamics and directly affect lateral salinity gradients. In this study, an idealized model is applied to investigate the effects of groyne layouts in estuarine environments, including effects on (1) channel hydrodynamics, (2) lateral water exchange, (3) Coriolis effects, and (4) saltwater intrusion. Model results show that the aspect ratio (the width of groyne fields to the length of groynes) of groyne fields plays an important role. Groynes also induce asymmetry of lateral flows, for example, increasing near-bottom shoal-to-channel flows during low water slack. The aspect ratio has opposite effects on horizontal and vertical components of water exchange. A large aspect ratio strengthens horizontal exchange and weakens density-driven currents. For a large-scale groyne field (several kilometers), Coriolis effects introduce a substantial difference in exchange mechanisms along the north and south banks. A medium range of aspect ratio (2.0-3.0) leads to the strongest saltwater intrusion during both neap and spring tides.","","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-04-20","","","Environmental Fluid Mechanics","","",""
"uuid:c7aae6a5-8580-49ec-a906-099aa430f350","http://resolver.tudelft.nl/uuid:c7aae6a5-8580-49ec-a906-099aa430f350","Implementation of Active Damping Control Methodology on Modular Multilevel Converter(MMC)-Based Arbitrary Wave Shape Generator Used for High Voltage Testing","Zhou, Xiaochuan (Student TU Delft); Ganeshpure, D.A. (TU Delft High Voltage Technology Group); Soeiro, Thiago B. (University of Twente); Ghaffarian Niasar, M. (TU Delft High Voltage Technology Group); Wu, Y. (TU Delft DC systems, Energy conversion & Storage); Vaessen, P.T.M. (TU Delft High Voltage Technology Group; KEMA Laboratories)","","2023","In order to damp the resonance in the MMC-based Arbitrary Wave shape Generator (AWG) used for high voltage testing, an active damping control methodology is proposed in this paper instead of the passive damping with an arm resistor. It is vital to ensure the system’s stability when such an active damping closed loop control is implemented. Consequently, optimal parameters of a PI controller are designed by analyzing the stability margins of the involved transfer function using Bode-Plots. The performance of the designed active damping control methodology and the PI controller have been demonstrated with a 50 Hz sinusoidal waveform and arbitrary waveforms such as triangular, trapezoidal, and complex waveforms in MATLAB-Simulink. These results proves that the output voltage can track the reference without any reasonable error and does not contain any resonant frequency. Additionally, the Total Harmonic Distortion (THD) of the sinusoidal waveform and other arbitrary waveforms is less than 1% with the Phase Shift Carrier (PSC) modulation technique.","Modular Multilevel Converters (MMC); Phase-Shift Mode; Active damping; Controllers PI control; Stability analysis","en","conference paper","IEEE","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-04-02","","","High Voltage Technology Group","","",""
"uuid:2c412848-cbd8-4a05-bbf2-186bff72df76","http://resolver.tudelft.nl/uuid:2c412848-cbd8-4a05-bbf2-186bff72df76","Numerical Simulation of Grid-Generated Turbulence Interaction with a NACA0012 Airfoil","Trascinelli, L. (University of Bristol); Bowen, Luke (University of Bristol); Piccolo, A. (TU Delft Wind Energy); Zamponi, R. (TU Delft Wind Energy); Ragni, D. (TU Delft Wind Energy); Avallone, F. (Politecnico di Torino); Zhou, Beckett Y. (University of Bristol); Zang, Bin (University of Bristol)","","2023","The present study assesses the ability to numerically predict turbulence-interaction noise of a NACA0012 airfoil with grid-generated turbulence by utilizing the Lattice Boltzmann solver PowerFLOW. Both the near-field flow characteristics and far field noise are bench-marked against an existing experimental study. The grid was chosen to match that from the experiment to provide evidence that the present numerical approach in physically placing a grid upstream of the airfoil can reproduce the turbulence characteristics observed from the benchmark experiment and thus accurately capture the turbulence-interaction noise generated. The comparison of the results show that the turbulence statistics, including turbulence intensity, integral length scales and anisotropy are highly consistent with the experiment. Moreover, far field acoustics of the turbulence interaction as well as the near-field flow properties near the leading-edge and the unsteady wall pressure fluctuations of the airfoil are also analyzed and the results agreed well with the experimental measurements. The present study confirms that the grid-generated approach is suitable for numerical investigation of turbulence-interaction noise and its potential mitigation strategies.","","en","conference paper","American Institute of Aeronautics and Astronautics Inc. (AIAA)","","","","","","","","","","Wind Energy","","",""
"uuid:cebe0aa1-b8d1-4b70-a094-3d1b9b9b1532","http://resolver.tudelft.nl/uuid:cebe0aa1-b8d1-4b70-a094-3d1b9b9b1532","Metro systems: Construction, operation and impacts","Lin, Dong (University of Aberdeen); Zhou, Zhipeng (Nanjing University of Aeronautics and Astronautics); Weng, Miaocheng (Chongqing University); Broere, W. (TU Delft Geo-engineering); Cui, Jianqiang (Griffith University)","","2023","Metro systems have been in use for over 150 years, and new metro lines are still being constructed, either as new metro systems or as expansions of existing metro networks. In many cities the metro system is an essential form of transport to keep the cities functioning. This overview compares the findings of various international studies on metro construction and operation, and the impact that metro systems have on cities. The uncertainties inherent in underground construction, with sometimes uncertain hydro-geological conditions and impacts from nearby existing construction projects, are often apparent during metro construction, and have been widely studied. Similarly, passenger comfort and safety during operation is a topic that has received widespread attention, with the main focus on fire safety, as fire poses the most dangerous risk during operation. More recently, passenger comfort related to indoor air quality and aerodynamic effects has received increased attention. The vulnerability of the running stock and the metro network is a significant factor when determining the safety and efficiency of the metro system. Metro efficiency and reliability have a major impact on the transport, economic, environmental and social aspects of cities. Even though they are designed as separated own-right-of-way transport systems, metro systems strongly influence urban development and drive spatial changes in land use. The combination of metro systems with other urban functions provides great potential for the development of urban underground space and the development of more resilient and efficient urban areas. This in turn has an impact on housing prices and produces wider economic benefits beyond the city. Metro systems have also been shown to affect travel behaviour and have a positive impact on public health and environmental quality, by reducing pollution and emissions, despite the large concentration of passengers present in the metro, which brings its own problems. After an overview of the leading and more recent research topics in these areas, the key research gaps are discussed and recommendations for future research are made.","","en","journal article","","","","","","","","","","","Geo-engineering","","",""
"uuid:9721197d-bb95-4784-930c-2531821e1b86","http://resolver.tudelft.nl/uuid:9721197d-bb95-4784-930c-2531821e1b86","Laser shape variation influence on melt pool dynamics and solidification microstructure in laser powder bed fusion","Li, Erlei (University of Queensland); Shen, Haopeng (CSIRO Manufacturing, Victoria); Wang, L. (TU Delft QN/Akhmerov Group); Wang, Geoff (University of Queensland); Zhou, Zongyan (Monash University; Jiangxi University of Science and Technology)","","2023","The shape variation of the laser beam is evidently observed in the laser powder bed fusion (LPBF) process because of changes in laser incidence angle and misalignment between the build plate and the laser focus plane. This issue is particularly relevant in large-scale LPBF systems where the laser beam needs to scan a large build area. However, most LPBF modeling studies assume vertical laser radiation. The heat transfer, melt pool, and solidification evolution due to the laser shape variation have not been well addressed and quantified. In the present study, the temperature distribution, melt pool geometry and flow dynamics are captured via numerical modelling, and the grain morphology is characterized under various laser incidence angles. The results show that the melt pool depth becomes shallower, and the width is near the beam size as the laser beam becomes more elongated. The beam shape variation can affect the liquid flow pattern with increasing incidence angle, resulting in a larger vortex at the front of the melt pool and a smaller vortex at the rear of the melt pool. The thermal gradient increases and the solidification rate decreases as the laser incident angle becomes larger. The present study enhances the understanding of multi-physics in the LPBF process.","Laser incidence angle; Laser powder bed fusion; Laser shape variation; Melt pool dynamics; Solidification microstructure","en","journal article","","","","","","","","","","","QN/Akhmerov Group","","",""
"uuid:ef6439f8-937a-4559-8c77-70c1c7650932","http://resolver.tudelft.nl/uuid:ef6439f8-937a-4559-8c77-70c1c7650932","Numerical simulation of a managed aquifer recharge system designed to supply drinking water to the city of Amsterdam, The Netherlands","Pokhrel, Pranisha (Universiteit Utrecht; IHE Delft Institute for Water Education); Zhou, Yangxiao (Hebei University; IHE Delft Institute for Water Education); Smits, F.J.C. (TU Delft Water Resources; Waternet); Kamps, Pierre (Waternet); Olsthoorn, T.N. (Waternet)","","2023","Managed aquifer recharge (MAR) is increasingly used to secure drinking water supply worldwide. The city of Amsterdam (The Netherlands) depends largely on the MAR in coastal dunes for water supply. A new MAR scheme is proposed for the production of 10 × 106 m3/year, as required in the next decade. The designed MAR system consists of 10 infiltration ponds in an artificially created sandbank, and 25 recovery wells placed beneath the ponds in a productive aquifer. Several criteria were met for the design, such as a minimum residence time of 60 days and maximum drawdown of 5 cm. Steady-state and transient flow models were calibrated. The flow model computed the infiltration capacity of the ponds and drawdowns caused by the MAR. A hypothetical tracer transport model was used to compute the travel times from the ponds to the wells and recovery efficiency of the wells. The results demonstrated that 98% of the infiltrated water was captured by the recovery wells which accounted for 65.3% of the total abstraction. Other sources include recharge from precipitation (6.7%), leakages from surface water (13.1%), and natural groundwater reserve (14.9%). Sensitivity analysis indicated that the pond conductance and hydraulic conductivity of the sand aquifer in between the ponds and wells are important for the infiltration capacity. The temperature simulation showed that the recovered water in the wells has a stable temperature of 9.8–12.5 °C which is beneficial for post-treatment processes. The numerical modelling approach is useful and helps to gain insights for implementation of the MAR.","Infiltration capacity; Managed aquifer recharge; Numerical modelling; Recovery efficiency; The Netherlands","en","journal article","","","","","","","","","","","Water Resources","","",""
"uuid:1f2ad684-f792-456d-958e-f159f32c9073","http://resolver.tudelft.nl/uuid:1f2ad684-f792-456d-958e-f159f32c9073","Effects of downstream environmental flow release on enhancing the groundwater recharge and restoring the groundwater/surface-water connectivity in Yongding River, Beijing, China","Liu, S. (TU Delft Water Resources; IHE Delft Institute for Water Education); Zhou, Yangxiao (IHE Delft Institute for Water Education; Hebei University of Geosciences); Zang, Yining (IHE Delft Institute for Water Education); McClain, M.E. (TU Delft Water Resources; IHE Delft Institute for Water Education); Wang, Xu sheng (China University of Geosciences)","","2023","The Yongding River (Beijing, China) was dry most times of the year, and groundwater storage was severely depleted. To address this issue, a river rehabilitation project was initiated. A downstream environmental flow release (EFR) project from upstream reservoirs has been implemented since 2019. This study evaluated the impact of EFR by constructing transient groundwater-flow and numerical tracer transport models to simulate the hydrogeological responses to the water release events in 2019–2020. The study identified two factors that significantly influence the river leakage rate, which are operational factors (i.e., water release rate and duration) and physical factors (i.e., hydraulic properties of the riverbed, regional hydraulic gradients, and groundwater depth) that determine the maximum water availability for groundwater recharge and maximum infiltration capacity, respectively. Predictive modelling was performed to assess the long-term effects of the proposed EFR scheme from 2021 to 2050, which showed that groundwater levels along the river will increase by 10–20 m by 2050. Groundwater storage is expected to be largely recovered and groundwater/surface-water connectivity in the middle reach of the river will be restored. This restoration will not only maintain the environmental flow for the benefit of ecosystems but also enhance groundwater recharge, promoting sustainable groundwater development in the region. Overall, this study provides valuable insights into the effectiveness of the proposed EFR scheme in achieving sustainable groundwater development in the region.","China; Environmental flow release; Groundwater recharge; Groundwater/surface-water relations; Numerical simulations","en","journal article","","","","","","","","","","","Water Resources","","",""
"uuid:c968a864-bee6-4bcb-8c2a-85b073bbdaed","http://resolver.tudelft.nl/uuid:c968a864-bee6-4bcb-8c2a-85b073bbdaed","Recycling waste tyre polymer for production of fibre reinforced cemented tailings backfill in green mining","Guo, Z. (TU Delft Rivers, Ports, Waterways and Dredging Engineering; Northeastern University); Qiu, Jingping (Northeastern University); Kirichek, Alex (TU Delft Rivers, Ports, Waterways and Dredging Engineering); Zhou, Hao (Shougang Group Co., Ltd.); Liu, C. (TU Delft Materials and Environment); Yang, Lei (Johns Hopkins University)","","2023","The increasing amount of solid waste, e.g., waste tyres from car industry and tailings from mine operations, causes substantial environmental and societal issues. The recycled tyre polymer fibre (RTPF) reinforced cemented tailings backfill (CTB) is a kind of composite that can treat waste tyres and tailings simultaneously and realize green mining, but its engineering properties have not been well understood. In this study, the rheology (i.e., static and dynamic yield stress, and structural build-up), strength (i.e., uniaxial and triaxial compressive, splitting tensile and flexural strengths), microstructure, and life cycle of RTPF reinforced CTB are comprehensively evaluated. For comparison, the engineering performance of the commonly used polypropylene fibre (PPF) reinforced CTB in mines is tested. The experimental results demonstrate that incorporating 0.6 wt% RTPF into CTB can achieve comparable fluidity and strength to the CTB reinforced with 0.3 wt% PPF at reduced cost and improved sustainability. A strength enhancement approach for RTPF reinforced CTB is also developed by adjusting the viscosity of suspending CTB before the addition of RTPF. With this approach, the splitting tensile strength increases by 68 %. The results obtained from this study pave the way for promoting the recycling of abandoned waste tyres and the safe design of backfill structures in mines.","Solid waste utilization; Recycled Tyre polymer fibre; Cemented tailings backfill; Rheology; Strength; Microstructure","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-05-08","","","Rivers, Ports, Waterways and Dredging Engineering","","",""
"uuid:354e9b05-5175-4d54-a93e-10c3a18d69ec","http://resolver.tudelft.nl/uuid:354e9b05-5175-4d54-a93e-10c3a18d69ec","Optimal Design of Multilayer Optical Color Filters for Building-Integrated Photovoltaic (BIPV) Applications","Ortiz Lizcano, J.C. (TU Delft Photovoltaic Materials and Devices); Villa, Simona (DIANA FEA); Zhou, Y. (TU Delft Photovoltaic Materials and Devices); Frantzi, Georgia (Student TU Delft); Vattis, Kyriakos (Student TU Delft); Calcabrini, A. (TU Delft Photovoltaic Materials and Devices); Yang, G. (TU Delft Photovoltaic Materials and Devices); Zeman, M. (TU Delft Photovoltaic Materials and Devices); Isabella, O. (TU Delft Photovoltaic Materials and Devices)","","2023","Herein, the application of a comprehensive modeling framework that can help optimize the design of multilayered optical filters for coloring photovoltaic (PV) modules is presented based on crystalline silicon solar cells. To overcome technical issues related to the implementation of color filters (CFs) on PV modules, like glare and color instability, colorimetry metrics, such as the hue, chroma, luminance color space, and the quantitative concept of difference between two colors are extensively deployed. It is showcased in this work that designing colored modules with high hue and chroma stability is possible by using a front-side texturing with edged geometry, like V-shaped grooves and inverted pyramids, while obtaining colors with relatively high luminance values, indicating good brightness. Furthermore, it is argued that adapting the rear surface of the front glass with a random textured layout where the CF is applied can improve color and luminance stability without significant loss of chroma while eliminating glare. Finally, the models can be used to optimize the number of layers for a given CF, reducing unnecessary optical losses. Compared to a standard PV module, performance simulation of optimized, bright-colored PV modules predicts relative energy yield losses ranging from 7% to 25%.","colors; design; integration; performance; photovoltaics","en","journal article","","","","","","","","","","","Photovoltaic Materials and Devices","","",""
"uuid:24c00e56-8ae5-4f5e-be6c-2c53b4e24603","http://resolver.tudelft.nl/uuid:24c00e56-8ae5-4f5e-be6c-2c53b4e24603","Update Scheduling for ADMM-based Energy Sharing in Virtual Power Plants Considering Massive Prosumer Access","Feng, Cheng (Tsinghua University); Zheng, Kedi (Tsinghua University); Zhou, Yangze (Zhejiang University); Palensky, P. (TU Delft Electrical Sustainable Energy); Chen, Qixin (Tsinghua University)","","2023","With the proliferation of distributed energy resources (DERs), electricity consumers in virtual power plants (VPPs) are transitioning into prosumers and are encouraged to share surplus energy with peers. Nevertheless, large-scale energy sharing among thousands of prosumers may encounter communication-related challenges. Communication network congestion may result in a significant increase in the negotiation waiting time to reach a sharing agreement, and potentially risks exceeding the deadline of negotiation before the market gate closes, rendering energy sharing ineffective. This paper proposes an online partial-update algorithm for the alternating direction method of multipliers (ADMM)-based energy sharing. By restricting the update connection between the VPP and the prosumers, the algorithm selects a subset of the prosumers participating in ADMM updates each round, hence eliminating the excessively long waiting time caused by communication congestion. Considering the delay induced by massive prosumer communication access requests, a method for determining the optimal number of prosumers participating in updates is provided. To fully utilize the limited update opportunities, a fair and efficient prosumer update scheduling policy is designed. The VPP schedules the participation of prosumers in updates such that the convergence-critical prosumers receive higher priority, yet every prosumer is granted sufficient update opportunities. Additionally, the extra computation and communication overheads brought by the prosumer scheduling are minimized, allowing the whole algorithm to be executed in real time. Numerical studies are conducted to validate the effectiveness of the algorithm and its performance in reducing the overall convergence time.","Energy Sharing; Virtual Power Plant; ADMM; Machine type Communications; Access Delay; Update Scheduling; Distributed Energy Resource","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-02-23","","Electrical Sustainable Energy","","","",""
"uuid:fc61380c-de2e-48f4-89e4-d6ad554af389","http://resolver.tudelft.nl/uuid:fc61380c-de2e-48f4-89e4-d6ad554af389","The impact of product features on market orientation in technology-based new ventures","Zhou, Zhao (Shanghai University of Finance and Economics); Verburg, R.M. (TU Delft Economics of Technology and Innovation)","","2023","Little is known about the role of product features in shaping market orientation as most research focuses on organizational features, such as interdepartmental connectedness, centralization in the strategy formation process, and the nature of top management teams. In this study we draw on the theory of resource orchestration and hypothesize that the protect-ability and the scalability of new products relate positively to market orientation in technology-based new ventures. We also predict that the entrepreneurial experience of founders interacts positively with these product features in driving market orientation strategies. On the basis of original field data from 156 technology-based startups, we find support for the positive relationship between product features and market orientation and the proposed interaction. These findings contribute to the ongoing research on the antecedents of market orientation by showing how founders’ experience and product features shape the resource orchestration process within technology-based new ventures.","Market orientation; Product protect-ability; Product scalability; Resource orchestration theory; Technology entrepreneurship","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-02-24","","","Economics of Technology and Innovation","","",""
"uuid:bc66857f-33c9-4881-b146-056c9e64a120","http://resolver.tudelft.nl/uuid:bc66857f-33c9-4881-b146-056c9e64a120","Geospatial analysis of Indonesia's bankable utility-scale solar PV potential using elements of project finance","Langer, J.K.A. (TU Delft Energie and Industrie); Roosenboom-Kwee, Z. (TU Delft Economics of Technology and Innovation); Zhou, Y. (TU Delft Photovoltaic Materials and Devices); Isabella, O. (TU Delft Photovoltaic Materials and Devices); Ashqar, Ziad (Student TU Delft); Quist, J.N. (TU Delft Energie and Industrie); Praktiknjo, Aaron (Rheinisch-Westfälische Technische Hochschule); Blok, K. (TU Delft Energie and Industrie)","","2023","Geospatial analysis is useful for mapping the potential of renewables like solar PV. However, recent studies do not address PV’s bankable potential for which project financing can be secured. This paper proposes a framework that incorporates project finance into geospatial analyses to obtain the bankable potential of renewables. We demonstrate our framework for Indonesia, and compare the bankable potential with the socio-economic potential mostly used in literature. Using average inputs On average, the technical potential is 12,200 TWh/year and the socio-economic potential is 152.7 TWh/year if capped by 2030 demand (34% coverage). Considering PV’s financing risks, PV’s bankable potential is 16.0 TWh under current conditions if capped by 2030 demand (3.6% coverage). Both economic potentials are mainly in East Indonesia and absent on Java due to tariffs and land availability. For the bankable potential, the risk perception by banks and investors is another key influence. With a feed-in tariff of 11.5 US¢(2021)/kWh and temporary lift of import restrictions, the bankable potential is 23 TWh if capped by 2030 demand (5.2% coverage) and spreads to Java. For more widespread bankability, additional temporary measures are recommended until the PV’s costs have decreased further and trust by financial institutions has increased.","Solar PV; Geospatial Analysis; Project finance; Economic analysis; Indonesia; Monte Carlo simulation","en","journal article","","","","","","","","","","","Energie and Industrie","","",""
"uuid:169bf19f-9272-461b-af8c-1d57c0a86a83","http://resolver.tudelft.nl/uuid:169bf19f-9272-461b-af8c-1d57c0a86a83","A Petri-net approach for firefighting force allocation analysis of fire emergency response with backups","Zhou, Jianfeng (Guangdong University of Technology); Reniers, G.L.L.M.E. (TU Delft Safety and Security Science; Universiteit Antwerpen; Katholieke Universiteit Leuven); Cozzani, Valerio (University of Bologna)","","2023","Fire is one of the main accident scenarios occurring in chemical and process plants, and it can lead to domino effects due to thermal radiation. Emergency response is necessary to prevent fire escalation, in addition to safety barriers. In major industrial fire accidents, backup is usually required in emergency response, due to the lack of emergency response capacity of a single emergency response department. A method addressing the optimal allocation of emergency response forces, specifically considering the front-line departments, is developed in the present study. The emergency response of the front-line departments can reduce the thermal radiation received by the equipment adjacent to the primary fire and thus prolong the time to failure of the equipment, such that the backups have more time to get to the fire scene. The allocation analysis of emergency response teams is carried out considering the dynamic ttf of an adjacent equipment item resulting from the change in time of the thermal radiation received. A timed colored hybrid Petri-net (TCHPN) approach is proposed to model the emergency response process. The probability of preventing fire escalation is obtained from the TCHPN model and the optimal allocation of firefighting forces is determined. A case study illustrates the proposed approach, two scenarios are compared and results show that if a request for backup can be issued immediately according to the fire state, fewer emergency forces can be deployed on the front line department, such as the reduction from 6 emergency response teams to 3 teams to maintain the success probability of 0.91. The influence of other factors such as the position of fire departments and the layout of tanks on the allocation of emergency forces is also discussed.","Allocation analysis; Domino effect; Emergency response; Fire escalation; Petri-net","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Safety and Security Science","","",""
"uuid:10b4e1ea-9420-4e98-8cf6-fa75fdd9ed9d","http://resolver.tudelft.nl/uuid:10b4e1ea-9420-4e98-8cf6-fa75fdd9ed9d","A data-driven high spatial resolution model of biomass accumulation and crop yield: Application to a fragmented desert-oasis agroecosystem","Chen, Qiting (Chinese Academy of Sciences); Jia, Li (Chinese Academy of Sciences); Menenti, M. (TU Delft Optical and Laser Remote Sensing; Chinese Academy of Sciences); Hu, Guangcheng (Chinese Academy of Sciences); Wang, Kun (Chinese Academy of Sciences); Yi, Zhiwei (Chinese Academy of Sciences); Zhou, Jie (Central China Normal University); Peng, Fei (Chinese Academy of Sciences, Lanzhou); Ma, Shaoxiu (Chinese Academy of Sciences, Lanzhou)","","2023","Information on crop yield is important for food security, in particular under the conditions of climate change and growing population worldwide. We developed a new fully distributed, high spatial resolution, model of biomass accumulation and crop yield applicable to a highly heterogeneous desert-oasis agroecosystem. The bulk of required input data is obtained by retrieving pixel-wise biogeophysical variables from a suite of very diverse satellite data. Both temperature and water stress conditions at field-scale are given full consideration, while the model was designed to strike a balance between model applicability and satisfactory characterization of the heterogeneous desert-oasis system to estimate field-scale yield. The development of this model relies on three main innovations. First, the start and end of the growing season were estimated for each pixel by calibrating the high spatial and temporal resolution observations of Normalized Difference Vegetation Index (NDVI) by Sentinal-2 (S2) MSI (Multi-Spectral Instrument) against limited local phenological information. Second, to monitor crop water stress, account taken of irrigation, a process-based water and energy balance model was applied to estimate the actual evapotranspiration (ET). This requires knowledge of soil water availability, which is characterized by downscaling the ASCAT (Advanced SCATterrometer) soil moisture data product. To capture the dominant features of the eco-hydrological conditions in the desert and oasis agroecosystem, ET was further downscaled from the 1 km resolution. Third, likewise the water stress indicator, the air temperature stress indicator was mapped after characterizing the thermal contrast and heterogeneity of the desert-oasis system, by generating time series of air temperature at 1 km spatial resolution using the MODIS (Moderate Resolution Imaging Spectroradiometer) Land Surface Temperature (LST) data product. In the temporal dimension, gaps were mitigated by applying time series analysis techniques to reconstruct cloud-free time series of LST, NDVI, fAPAR and albedo. These innovations add up to a high resolution characterization of crop response to the geospatial variability of weather and climate forcing in the desert-oasis agroecosystem. The model was applied to the dominant crops, i.e., spring wheat, maize, sunflower, and melon, in the oases of the Shiyang River Basin (northwestern China) characterized by a rather fragmented land use. The high resolution of pixel-wise ecohydrological parameters, i.e., crop phenology, temperature stress and water stress factors successfully reflect differences of crops with different phenology and location in the oases. The relative errors for wheat and maize yields compared to the census data are less than 5% at district level. At the county level, the relative errors of wheat yields of Liangzhou, Minqin, Gulang, Jinchuan, and Yongchang equal to 0.87%, 24.2%, 9.7%, 12.5%, and 7.2%. For maize, the dominant crop, the error on estimated yields was less than 5%, except in Gulang. The relative error on estimated yield for sunflower was less than 10% compared to agricultural census data. The relative error on estimated melon yield was 16%. This performance highlights the applicability of the model to estimate field-scale yields in agroecosystems characterized by fragmented land use.","Crop yield estimation; Heterogeneous agroecosystem; High resolution; Multi-source remote sensing data","en","journal article","","","","","","","","","","","Optical and Laser Remote Sensing","","",""
"uuid:ae0bd627-4a17-4395-9f0b-0c8428533e3a","http://resolver.tudelft.nl/uuid:ae0bd627-4a17-4395-9f0b-0c8428533e3a","High Cationic Dispersity Boosted Oxygen Reduction Reactivity in Multi-Element Doped Perovskites","Li, Wenhuai (Nanjing Tech University); Li, Mengran (TU Delft ChemE/Materials for Energy Conversion and Storage); Guo, Y. (Nanjing Tech University); Hu, Zhiwei (Max Planck Institute for Chemical Physics of Solids); Zhou, Chuan (Nanjing Tech University); Brand, Helen E.A. (Australian Nuclear Science and Technology Organisation); Peterson, Vanessa K. (Australian Nuclear Science and Technology Organisation); Pao, Chih Wen (Australian Nuclear Science and Technology Organisation); Chen, Chien Te (National Synchrotron Radiation Research Center, Hsinchu)","","2023","Oxygen-ion conducting perovskite oxides are important functional materials for solid oxide fuel cells and oxygen-permeable membranes operating at high temperatures (>500 °C). Co-doped perovskites have recently shown their potential to boost oxygen-related kinetics, but challenges remain in understanding the underlying mechanisms. This study unveils the local cation arrangement as a new key factor controlling oxygen kinetics in perovskite oxides. By single- and co-doping Nb5+ and Ta5+ into SrCoO3-δ, dominant factors affecting oxygen kinetics, such as lattice geometry, cobalt states, and oxygen vacancies, which are confirmed by neutron and synchrotron X-ray diffraction as well as high-temperature X-ray absorption spectroscopy, are controlled. The combined experimental and theoretical study unveils that co-doping likely leads to higher cation dispersion at the B-site compared to single-doping. Consequently, a high-entropy configuration enhances oxygen ion migration in the lattice, translating to improved oxygen reduction activity.","configuration entropy; local cation arrangement; oxygen reduction reaction; perovskite oxides; solid oxide fuel cell","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","ChemE/Materials for Energy Conversion and Storage","","",""
"uuid:4cf4c51a-6995-4fb3-bb07-2803625aa802","http://resolver.tudelft.nl/uuid:4cf4c51a-6995-4fb3-bb07-2803625aa802","Self-assembly of ammonium assimilation microbiomes regulated by COD/N ratio","Han, Fei (Shandong University); Zhang, Mengru (Shandong University); Li, Zhe (Shandong University); Liu, Zhe (School of Environmental Science and Engineering; Shandong University); Han, Yufei (Shandong University); Li, L. (TU Delft Sanitary Engineering); Zhou, Weizhi (Shandong University)","","2023","Marine microorganisms have an inherent advantage in the treatment of saline wastewater due to their halophilic properties. Ammonium assimilation is the most important and common nitrogen conversion pathway in the ocean, which means that it may be a suitable nitrogen removal strategy under high salinity conditions. However, the targeted construction of engineering microbiomes with ammonium assimilation function for nitrogen recovery has not been realized. Here, we constructed four halophilic ammonium assimilation microbiomes from marine microbial community under varying chemical oxygen demand (COD) to nitrogen (COD/N) ratios. The regulation of COD/N ratio on microbial self-assembly was explored at the phenotypic, genetic, and microbial levels. The results of nitrogen balance tests, functional genes abundance and microbial community structure confirmed that the microbiomes regulated by different COD/N ratios all performed obligate ammonium assimilation functions. >93% of ammonium, 90% of TN, 98% of COD, and 82% of phosphorus were simultaneously removed by microbial assimilation under the COD/N ratio of 20. COD/N ratios significantly affected the self-assembly of microbiomes by selectively enriching heterotrophic microorganisms with different preference for organic carbon load. Additionally, the increase of COD/N ratio intensified the competition among species within the microbiome (the proportion of negative connections of microbial network increased from 5.0% to 24.4%), which may enhance the stability of community structure. Taken together, these findings can provide theoretical guidance for the construction and optimization of engineering microbiomes for synergistic nitrogen removal and recovery.","Ammonium assimilation microbiomes; Chemical oxygen demand to nitrogen (COD/N) ratios; Marine microbial community; Microbial network; Self-assembly process","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Sanitary Engineering","","",""
"uuid:9b8cd229-c7fe-434d-8b16-184ff4b63e7a","http://resolver.tudelft.nl/uuid:9b8cd229-c7fe-434d-8b16-184ff4b63e7a","Sustainable mobility strategies and their impact: A case study using a multimodal activity based model","Zhou, H. (TNO; Universiteit van Amsterdam); Dorsman, J.L. (Universiteit van Amsterdam); Mandjes, M. (Universiteit van Amsterdam); Snelder, M. (TU Delft Transport and Planning; TNO)","","2023","Nowadays, many cities are intending to reduce the use of private vehicles. Governments are incorporating new mobility services and are adapting their parking policies to promote a more sustainable mobility, as both strategies are believed to have the potential to reduce private vehicle use. To understand the effects of these strategies, one needs to be able to model complex travel behaviour up to a very high level of detail. Owing to their flexibility, robustness and ability to model travel activity behaviour on an individual level, activity based travel demand models (ABM) offer a highly suitable methodology for this purpose. In this paper, we employ this methodology to perform a case study in a metropolitan region in the Netherlands which surrounds and includes the cities of Rotterdam and The Hague. This region is of vital economic importance and has a very developed and dense road network. The population of this region is growing, which motivates the ambition to improve its accessibility and move towards sustainable mobility. Therefore, the findings of this study are important to similar regions seeking to do this as well. After setting up a suitable, calibrated ABM able to perform a comprehensive study on the effects of new mobility services and parking policy adaptations in the above-mentioned region, we design seven scenarios to give quantitative answers to policy-related questions on how altering features can reduce the extent to which private vehicles are used for travelling. These features include the availability of mobility hubs (hubs on neighbourhood level where sustainable travel modes are linked), the availability of car/bike sharing services, the availability of ‘Mobility as a Service’ (MaaS) subscriptions, the amount of parking capacity in the region and the parking costs. We also study what the impact would be of an improved public transport service with lowered public transport travel times to and from the city centers, and the impact of an improved cycling network infrastructure with significantly lowered travel times for bike and e-bike travellers. Based on the case study, we find that the introduction of mobility hubs alone has limited impact. However, combining this with making sharing services available to the public through MaaS subscriptions, there is a potential to reduce the number of car trips significantly, while the number of trips undertaken by a more sustainable (shared) e-bike increases as well as the number of so-called multi-modal mode trips (trips undertaken by a combination of various modes). Furthermore, improving the public transport service and micromobility network further increases the potential of mobility hubs in terms of making mobility more sustainable. The case study also shows that limiting parking capacity and increasing parking costs in the city centers is especially helpful for the reduction of vehicle use, leading to an improved car flow.","Activity based travel demand modelling; Case study; Metropolitan region Rotterdam and The Hague; Mobility hubs; New mobility services; Parking","en","journal article","","","","","","","","","","","Transport and Planning","","",""
"uuid:bf4b667a-7910-41d7-82be-6277ba76a408","http://resolver.tudelft.nl/uuid:bf4b667a-7910-41d7-82be-6277ba76a408","Capturing the uncertainty about a sudden change in the properties of time series with confidence curves","Zhou, C. (TU Delft Water Resources); van Nooijen, R.R.P. (TU Delft Water Resources); Kolechkina, A.G. (TU Delft Team Bart De Schutter)","","2023","The representation of uncertainty in results is an important aspect of statistical techniques in hydrology and climatology. Hypothesis tests and point estimates are not well suited for this purpose. Other statistical tools, such as confidence curves, are better suited to represent uncertainty. Therefore three parametric methods to construct confidence curves for the location of a sudden change in the properties of a time series, a change point (CP), are analyzed for three distributions: log-normal, gamma, and Gumbel. Two types of change are considered: a change in the mean and a change in the standard deviation. A question that confidence curves do not answer is how likely the null hypothesis of ‘no change’ is. A possible statistic to help answer this question, denoted by Un, is introduced and analyzed. It is compared to the statistic that underlies the Pettitt test. All methods perform well in terms of coverage and confidence set size. One method is based on the profile likelihood for a CP, the other two, first defined in this article, on the pseudolikelihood for a CP. The main advantage of the pseudolikelihood over the profile likelihood lies in the much lower computational cost. The confidence curves generated by the three methods are very similar. In a limited test on time series of measurements found in the literature, the methods gave results that largely matched those reported elsewhere. Some results are also given for an order one autoregressive series with a lognormal marginal distribution.","Change point detection; Confidence curves; L-moments; Likelihood; Method of moments; Pseudolikelihood; Structural break; Uncertainty","en","journal article","","","","","","","","","","","Water Resources","","",""
"uuid:90cd9fd8-110b-4ab0-8b60-1d6ae8d5cbe8","http://resolver.tudelft.nl/uuid:90cd9fd8-110b-4ab0-8b60-1d6ae8d5cbe8","Secure genotype imputation using homomorphic encryption","Zhou, Junwei (Wuhan University of Technology); Lei, Botian (Wuhan University of Technology); Lang, Huile (Wuhan University of Technology); Panaousis, Emmanouil (University of Greenwich); Liang, K. (TU Delft Cyber Security); Xiang, Jianwen (Wuhan University of Technology)","","2023","Genotype imputation estimates missing genotypes from the haplotype or genotype reference panel in individual genetic sequences, which boosts the potential of genome-wide association and is essential in genetic data analysis. However, the genetic sequences involve people's privacy, confirming an individual's identification and even disease information. This work proposes a secure genotype imputation model, which uses a linear regression model and the homomorphic encryption scheme over ciphertext to impute missing genotypes. The inference model is trained with float plaintext parameters, which are round into integers to avoid high complexity homomorphic evaluation on float number operations without bootstrapping operations. Even though the rounding parameters in the inference model are not the same as those in the trained model, We find that it will no effect on the outcome of the homomorphic prediction. Thus, a high-efficiency genotype imputation inference model over the ciphertext is obtained while keeping the high-security level. The simulation results indicate that the accuracy of the secure inference model is almost the same as the original model trained on float parameters. The secure inference model's accuracy is 98.6% for a single genotype.","Genetic security; Genotype imputation; Homomorphic encryption; Privacy computing; Privacy-preserving","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Cyber Security","","",""
"uuid:d44b7d08-eff5-40c2-b936-4c738c982724","http://resolver.tudelft.nl/uuid:d44b7d08-eff5-40c2-b936-4c738c982724","A cross-scale ‘material-component-system’ framework for transition towards zero-carbon buildings and districts with low, medium and high-temperature phase change materials","Zhou, Yuekuan (The Hong Kong University of Science and Technology; HKUST Shenzhen-Hong Kong Collaborative Innovation Research Institute); Liu, Zhengxuan (TU Delft Design & Construction Management)","","2023","Transition towards a carbon-neutral district energy community calls for carbon elimination and offsetting strategies, and phase change materials (PCMs) with substantial potential latent energy density can contribute significantly to carbon neutrality through both carbon-positive (like PCM-based thermal control in solar PVs) and carbon-negative strategies (like waste-to-energy recovery). However, roadmap for PCMs’ application in carbon-neutral transition is ambiguous in the current academia, and a state-of-the-art overview on latent thermal storage is necessary. In this study, a comprehensive review was conducted on cutting-edge technologies for carbon-neutral transition with latent thermal storages. Both carbon-positive and carbon-negative strategies in the operational stage are reviewed. Carbon-positive solution mainly focuses on energy-efficient buildings, through a series of passive, active, and smart control strategies with artificial intelligence. Passive strategies, to enhance thermal inertia and thermal storage of building envelopes, mainly include free cooling, solar chimney, solar façade, and Trombe walls. Active strategies mainly include mechanical ventilations, active water pipe-embedded radiative cooling, and geothermal system integration. The ultimate target is to minimise building energy demands, with improved utilisation efficiency on natural heating (e.g., concentrated solar thermal energy, geothermal heating, and solar-driven ventilative heating) and cooling resources (e.g., ventilative cooling, geothermal cooling, and sky radiative cooling). As one of the most critical solutions to offset the released carbon emission, carbon-negative strategies with PCMs mainly include cleaner power production and waste heat recovery. Main functions of PCMs include energy efficiency enhancement on cleaner power production, steady steam production, steady heat flux via the latent storage capacity, and pre-heat purpose on waste heat recovery. A thermal energy interaction network with transportation is formulated with PCMs’ recovering heat from internal combustion engines and spatiotemporal energy sharing, to provide frontier research guidelines. Future studies are recommended to spotlight standard testing procedure and database, benchmarks for suitable PCMs selection, seasonal cascaded energy storage, nanofluid-based heat transfer enhancement in PCMs, anti-corrosion, compatibility, thermochemical stability, and economic feasibility of PCMs. This study provides a clear roadmap on developing PCMs for transition towards a carbon-neutral district energy community, together with applications, prospects, and challenges, paving the path for combined efforts from chemical materials synthesis and applications.","Carbon-neutral district energy community; Cleaner power production; Energy efficiency enhancement; Latent thermal storage; Low, medium and high-temperature PCMs","en","review","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Design & Construction Management","","",""
"uuid:3f8cfafc-be8b-4bfe-b683-e0db00d2bfeb","http://resolver.tudelft.nl/uuid:3f8cfafc-be8b-4bfe-b683-e0db00d2bfeb","粉末床熔融的多材料铺粉过程中粉末扩散的数值研究","Wang, L. (TU Delft Resources & Recycling); Li, Erlei (Monash University); Zhou, Zongyan (Monash University; University of Science and Technology Beijing); Zhang, Baicheng (University of Science and Technology Beijing); Yu, Aibing (Monash University)","","2023","Powder bed fusion additive manufacturing has been applied to the fabrication of functionally graded materials. A new design that allows the material composition to change along the direction perpendicular to the powder spreading has been reported in the literature. Based on this design, this work examines the quality of the graded spread powder layer with two powders, which have a large difference of density. The results reveal that during the spreading of graded powders, the volume of particles on the heavy powder side is deposited less than that on the light powder side, indicating that heavy particles diffuse to the light powder side. This diffusion is affected by the spreading speed, but not much by the layer gap. Large spreading speed causes more significant deviation. The results also show that particle size affects diffusion, indicating that decreasing the particle size of the heavy powder may be a solution to reduce diffusion. [Figure not available: see fulltext.]","DEM simulation; Functionally graded material; Powder bed fusion additive manufacturing; Powder spreading","zh","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-09","","","Resources & Recycling","","",""
"uuid:1b79c224-6848-42a3-8e93-8ab43a690f67","http://resolver.tudelft.nl/uuid:1b79c224-6848-42a3-8e93-8ab43a690f67","BI-IEnKF coupling model for effective source term estimation of natural gas leakage in urban utility tunnels","Wu, Jiansong (China University of Mining and Technology (Beijing)); Cai, Jitao (China University of Mining and Technology (Beijing)); Liu, Z. (TU Delft Civil Engineering & Geosciences; China University of Mining and Technology (Beijing)); Yuan, S. (TU Delft Safety and Security Science); Bai, Yiping (China University of Mining and Technology (Beijing)); Zhou, Rui (Tsinghua University)","","2023","As an effective way to facilitate the increasing demand for reliable infrastructure, energy supply and sustainable urban development, underground utility tunnels have been developed rapidly in recent years. Due to the widespread distribution of utility tunnels, the safe operation of natural gas pipelines accommodated in utility tunnels has caused great concern considering fire, explosion, and other coupling consequences induced by the gas pipeline leakage. However, the limited information on leakage source terms in accidental leakage scenarios could preclude timely consequence assessment and effective emergency response. In this study, a BI-IEnKF coupling source term estimation (STE) model is developed, with the combination of gas dispersion model, Bayesian inference (BI) and iterative ensemble Kalman filter (IEnKF) method, to achieve the effective source term estimation (including leakage location and leakage rate) and gas concentration distribution prediction. The newly developed model is first evaluated by the twin experiment with good reliability and accuracy. Furthermore, three contributing factors affecting the performance of the developed BI-IEnKF coupling STE model were investigated to assist parameter selection for practical use. Additionally, the novel application of mobile sensors serving as an alternative for fixed sensors is explored, and an application framework is sequentially given to guide the deployment of the developed coupling model in utility tunnels. The results show that the developed model has great performance in accuracy, efficiency and robustness, as well as the potential to be applied in actual utility tunnel scenarios. This study can provide technical supports for safety control and emergency response in the case of natural gas pipeline leakage accidents in utility tunnels. Also, it could be helpful to reasonable references for gas lekage monitoring system design.","Bayesian inference; Iterative ensemble Kalman filter; Natural gas leakage; Source term estimation; Utility tunnel","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-09-16","Civil Engineering & Geosciences","","Safety and Security Science","","",""
"uuid:0fd002f8-2386-4735-b5e7-a2fae3608152","http://resolver.tudelft.nl/uuid:0fd002f8-2386-4735-b5e7-a2fae3608152","Extracting mud invasion information using borehole radar - A numerical study","Zhou, F. (TU Delft Applied Geophysics and Petrophysics; China University of Geosciences, Wuhan); Giannakis, Iraklis (University of Aberdeen); Giannopoulos, Antonios (University of Edinburgh); Holliger, Klaus (University of Lausanne); Slob, E.C. (TU Delft Applied Geophysics and Petrophysics)","","2023","In hydrocarbon drilling, mud filtrate penetrates permeable formations and alters the pore fluid characteristics in the immediate vicinity of the borehole. Typically, the prevailing in situ pore fluids are displaced by the invading mud filtrate, which leads to gradually changing distributions of the fluid and electrical properties. Understanding this invasion process is crucial for the interpretation of logging data and associated reservoir evaluations. Conventional logging methods tend to be inadequate for this purpose as their resolution is too low. We find that invasion depth can be determined from borehole radar data using an optimized antenna configuration and time-lapse measurements. A series of parametric sensitivity analyses provide information about the effects of variations of the rock and fluid properties on the identification and extraction of borehole radar signals reflected from the invasion front. Our results suggest that by embedding the radar antennas in cavities filled with an absorbing dielectric material, it is possible to minimize the interference arising from the metal components of the logging tool. In the simulated reservoir scenario, a time-lapse measurement mode with a time interval of at least 6 h can reliably extract the radar signals reflected from the invasion front, and the proposed borehole radar has a lateral detection range from 0.15 to 1 m. A comprehensive range of parametric sensitivity analyses indicates that the signals reflected from the invasion front are principally influenced by oil viscosity, porosity, and mud and formation water salinity, as well as by molecular diffusion coefficient and cementation exponent. These properties and parameters should be carefully explored and assessed when applying borehole radar to evaluate mud invasion information in a reservoir environment.","borehole geophysics; ground-penetrating radar","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-09-01","","","Applied Geophysics and Petrophysics","","",""
"uuid:028a0f1d-691c-4864-a6d3-1acbf9457acf","http://resolver.tudelft.nl/uuid:028a0f1d-691c-4864-a6d3-1acbf9457acf","A Plant-inspired Light Transducer for High-performance Near-infrared Light Mediated Gas Sensing","Liang, Hongping (South China Normal University; Huizhou University); Guo, Xin (South China Normal University); Guo, Lanpeng (South China Normal University); Liu, Siying (South China Normal University); Zhan, Qiuqiang (South China Normal University); Yang, Haihong (The First Affiliated Hospital of Guangzhou Medical University); Li, Hao (South China Normal University); de Rooij, Nicolaas Frans (South China Normal University); Lee, Yi Kuen (The Hong Kong University of Science and Technology); French, P.J. (TU Delft Bio-Electronics); Wang, Yao (South China Normal University); Zhou, Guofu (South China Normal University)","","2023","Constructing near-infrared light (NIR) light-enhanced room temperature gas sensors is becoming more promising for practical application. In this study, learning from the structure and photosynthetic process of chlorophyll thylakoid membranes in plants, the first “Thylakoid membrane” structural formaldehyde (HCHO) sensor is constructed by matching the upconversion emission of the lanthanide-doped upconversion nanoparticles (UCNPs) and the UV–vis adsorption of the as-prepared nanocomposites. The NIR-mediated sensor exhibits excellent performances, including ultra-high response (Ra / Rg = 2.22, 1 ppm), low practical limit of detection (50 ppb), reliable repeatability, high selectivity, and broadband spectral response. The practicality of the NIR-mediated gas sensor is confirmed through the remote and external stimulation test. A study of sensing mechanism demonstrates that it is the UCNPs-based light transducer produces more light-induced oxygen species for gas response in the process of non-radiative/radiative energy transfer, playing a key role in significantly improving the sensing properties of the sensor. The universality of NIR-mediated gas sensors based on UCNPs is verified using ZnO, In2O3, and SnO2 systems. This work paves a way for fabricating high-performance NIR-mediated gas sensors and will expand the application fields of NIR light.","gas sensors; light transducers; NIR-mediation; thylakoid membranes; upconversion nanoparticles","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-09-04","","","Bio-Electronics","","",""
"uuid:43bc5020-1406-432c-bd2e-32c99d156c53","http://resolver.tudelft.nl/uuid:43bc5020-1406-432c-bd2e-32c99d156c53","A scalable software package for time series reconstruction of remote sensing datasets on the Google Earth Engine platform","Zhou, J. (TU Delft Optical and Laser Remote Sensing; Central China Normal University); Menenti, M. (TU Delft Optical and Laser Remote Sensing; Chinese Academy of Sciences); Jia, Li (Chinese Academy of Sciences); Gao, Bo (Capital Normal University); Zhao, Feng (Central China Normal University); Cui, Yilin (Central China Normal University); Xiong, Xuqian (Central China Normal University); Liu, Xuan (Central China Normal University); Li, Dengchao (The First Geological brigade of Hubei Geological Bureau)","","2023","Spatiotemporal residual noise in terrestrial earth observation products, often caused by unfavorable atmospheric conditions, impedes their broad applications. Most users prefer to use gap-filled remote sensing products with time series reconstruction (TSR) algorithms. Applying currently available implementations of TSR to large-volume datasets is time-consuming and challenging for non-professional users with limited computation or storage resources. This study introduces a new open-source software package entitled ‘HANTS-GEE’ that implements a well-known and robust TSR algorithm, i.e. Harmonic ANalysis of Time Series (HANTS), on the Google Earth Engine (GEE) platform for scalable reconstruction of terrestrial earth observation data. Reconstruction tasks can be conducted on user-defined spatiotemporal extents when raw datasets are available on GEE. According to site-based and regional-based case evaluation, the new tool can effectively eliminate cloud contamination in the time series of earth observation data. Compared with traditional PC-based HANTS implementation, the HANTS-GEE provides quite consistent reconstruction results for most terrestrial vegetated sites. The HANTS-GEE can provide scalable reconstruction services with accelerated processing speed and reduced internet data transmission volume, promoting algorithm usage by much broader user communities. To our knowledge, the software package is the first tool to support full-stack TSR processing for popular open-access satellite sensors on cloud platforms.","gap-filling; Google Earth Engine; HANTS; remote sensing; Time series reconstruction","en","journal article","","","","","","","","","","","Optical and Laser Remote Sensing","","",""
"uuid:51cb1c9e-69de-48da-8ff1-b86e897db2c3","http://resolver.tudelft.nl/uuid:51cb1c9e-69de-48da-8ff1-b86e897db2c3","Perceived Appropriateness: A Novel View for Remediating Perceived Inappropriate Robot Navigation Behaviors","Zhou, Y. (TU Delft Internet of Things; TU Delft Industrial Design Engineering)","","2023","Robots navigating in social environments inevitably exhibit behavior perceived as inappropriate by people, which they will repeat unless they are aware of them; hindering their social acceptance. This highlights the importance of robots detecting and adapting to the perceived appropriateness of their behavior, in line with what we found in a systematic literature review. Therefore, we have conducted experiments (both outdoor and indoor) to understand the perceived appropriateness of robot social navigation behavior, based on which we collected a dataset and developed a machine learning model for detecting such perceived appropriateness. To investigate the usefulness of such information and inspire robot adaptive navigation behavior design, we will further conduct aWoZ study to understand how trained human operators adapt robot behavior to people's feedback. In all, this work will enable robots to better remediate their inappropriate behavior, thus improving their social acceptance.","Adaptive Behavior; Human-Robot Interaction; Perceived Appropriateness; Social Navigation; Social Signal Processing","en","conference paper","IEEE","","","","","","","2023-09-13","Industrial Design Engineering","","Internet of Things","","",""
"uuid:989f8f75-93a1-470e-ac97-e5e6c40dbb0f","http://resolver.tudelft.nl/uuid:989f8f75-93a1-470e-ac97-e5e6c40dbb0f","Experimental and numerical study of Conoscopic Interferometry sensitivity for optimal acoustic pulse detection in ultrafast acoustics","Robin, M.P. (TU Delft Dynamics of Micro and Nano Systems); Guis, R.H. (TU Delft Dynamics of Micro and Nano Systems); Arabul, Mustafa Umit (ASML); Zhou, Zili (ASML); Pandey, Nitesh (ASML); Verbiest, G.J. (TU Delft Dynamics of Micro and Nano Systems)","","2023","Conoscopic interferometry is a promising detection technique for ultrafast acoustics. By focusing a probe beam through a birefringent crystal before passing it through a polarizer, conoscopic interferences sculpt the spatial profile of the beam. The use of these patterns for acoustic wave detection revealed a higher detection sensitivity over existing techniques, such as reflectometry and beam distortion detection. However, the physical origin of the increased sensitivity is unknown. In this work, we present a model, describing the sensitivity behavior of conoscopic interferometry with respect to the quarter-wave plate orientation and the diaphragm aperture, which is validated experimentally. Using the model, we optimize the detection sensitivity of conoscopic interferometry. We obtain a maximal sensitivity of detection when placing the diaphragm edge on the dark fringes of the conoscopic interference patterns. In the configurations studied in this work, conoscopic interferometry can be 18 dB more sensitive to acoustic waves than beam distortion detection.","Acoustic waves detection; Beam distortion detection; Conoscopic interferometry; Picosecond ultrasonics; Reflectometry","en","journal article","","","","","","","","","","","Dynamics of Micro and Nano Systems","","",""
"uuid:ab08c005-177c-4784-ba4e-b4cc32e2e96a","http://resolver.tudelft.nl/uuid:ab08c005-177c-4784-ba4e-b4cc32e2e96a","Ship behavior during encounters in ports and waterways based on AIS data: From theoretical definitions to empirical findings","Zhou, Y. (TU Delft Rivers, Ports, Waterways and Dredging Engineering; Wuhan University of Technology); Daamen, W. (TU Delft Transport and Planning); Vellinga, T. (TU Delft Rivers, Ports, Waterways and Dredging Engineering); Hoogendoorn, S.P. (TU Delft Transport and Planning)","","2023","Currently, the research on ship behavior during encounters focuses on evasive behavior during specific situations with existing risks of collision. However, the preliminary selection of encounters to refine the presented ship behavior is biased. To obtain a full understanding of all ship behavior during different encounters in ports and waterways, the encounter is defined from the viewpoint of the spatial-temporal co-existence of ships in the same waterway segments during the same period. Based on this definition, this paper investigates ship behavior through the encounter process with other ships. The proposed approach starts from the moment when the distance in between is minimum as the critical moment to recognize ship behavior change (course alteration and speed change) based on the Sliding Window algorithm. Thus, the encounter process is identified by the key behavior feature point into phases, being before decision-making, before the critical moment, after the critical moment, and after being past and clear. The relative movement factors are calculated according to the behavior status of both ships to describe the conditions, timing, and objective of behavior change during the dynamic process of encounters. The empirical findings based on one-year Automatic Identification System data in the port of Rotterdam are presented. In the overtaking encounters, as the give-way ship, about 14% of the overtaking ships do not take any evasive actions. Among the ships with behavior changes, the preference for course alteration and speed change is equal. As the stand-on ship, about 87% of the overtaken ships take cooperative maneuvers to facilitate the encounter, in which deceleration seems the primary choice. The timing of overtaken ship's behavior change is later than overtaking ship. For overtaking ships, the objective of course alteration is a clear passing distance of about 5 times her beam, 100m for overtaken ships irrespective of her own size. Regarding speed, the overtaking ship aims to reach a relative speed of 0.3 times her own SOG, while the objective for the overtaken ship is fixed at around 2–3 m/s. In the encounters of ships sailing in the opposite direction, most of the ships take maneuvers to change their course or speed. However, within the influence distance of 2 km, over 76% of the ships do not take any evasive behavior, which implies a passing-by situation. Based on the recognized key feature points of behavior change, statistical tests show the objective of clear passing distance has been reached beforehand. The behavior change during head-on situations could be due to the precautionary behavior of officers onboard in case of interaction between ships. The findings enrich the knowledge of ship behavior during different types of encounters in real-life navigation, which can be further applied to simulation models for ship behavior in ports and waterways.","AIS data; Encounter; Head-on situation; Overtaking situation; Ports and waterways; Ship behavior","en","journal article","","","","","","","","","","Transport and Planning","Rivers, Ports, Waterways and Dredging Engineering","","",""
"uuid:c2210e62-90e3-4879-a1cc-7cf509199dad","http://resolver.tudelft.nl/uuid:c2210e62-90e3-4879-a1cc-7cf509199dad","A novel supply chain network evolving model under random and targeted disruptions","Wang, Jiepeng (Beihang University; Beijing Key Laboratory of Emergency Support Simulation Technologies for City Operations); Zhou, Hong (Beihang University; Beijing Key Laboratory of Emergency Support Simulation Technologies for City Operations); Sun, Xinlei (Nanjing University of Aeronautics and Astronautics); Yuan, Y. (TU Delft Transport and Planning)","","2023","Due to the fact that there is a lack of comprehensive understanding of how the dynamic nature of supply chain networks (SCNs) interrelates with network structures, particularly network topologies under disruptions. This research employs a novel evolving model of a supply chain network (SCNE model) by modifying the Barabási and Albert (BA) model to capture the phenomenon of regional economy and the factor of firms’ attractiveness, considering the degree, the locality preference, and the heterogeneity of SCN members simultaneously. We then analyze the SCNE model via the mean-field theory and conduct simulation study to identify the scale-free characteristic of the proposed supply chain network model. Additionally, we leverage node and edge removal to emulate random and targeted disruptions. We measure and compare the robustness of four network models, i.e., the SCNE model, the Erdos and Rényi (ER) model, the BA model, and the Watts and Strogatz (WS) model using two essential metrics, i.e., the size of the largest connected component and the network efficiency. We find that the robustness of the SCNE model is better than the BA model and the WS model on the whole in the presence of disruptions. Also, from the node level, the SCNE model maintains resilience, behaving similarly to the ER model against random disruptions while it shows vulnerability under targeted disruptions, responding in line with the BA model and the WS model. From the edge level, the network efficiency of the SCNE model changes slowly, and the topological structure of the SCNE model slightly changes initially but decreases rapidly at some value, as well as the BA model, the WS model, and the ER model. Based on the results, we summarize key points of the implications for research and practice in supply chain management.","Complex network; Robustness; Simulation; Supply chain disruptions; Supply chain management","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-09-27","","","Transport and Planning","","",""
"uuid:8e299658-4bc6-4627-bab7-3985684bea05","http://resolver.tudelft.nl/uuid:8e299658-4bc6-4627-bab7-3985684bea05","Modelling preferential flow induced by dynamic changes of desiccation cracks: A comparative numerical study","Luo, Y. (TU Delft Water Resources; China University of Geosciences, Wuhan); Zhang, Jiaming (China University of Geosciences, Wuhan); Zhou, Zhi (Hubei University Of Economics); Victor, Chikhotkin (China University of Geosciences, Wuhan)","","2023","Quantitative investigation on the preferential flow induced by desiccation cracks (PF-DC) remains a great challenge due to the soil shrinking-swelling behavior. This work presents a series of comparative numerical studies to investigate the accuracy and substitutability of different models in simulating the water flux, hydrological response and crack evolution induced by PF-DC. As a comparative study, an effective dynamic dual-permeability model (DDPM) we recently developed and validated was regarded as a benchmark model. Three numerical experiments were conducted to (i) compare the difference among the single-domain model (SDM), rigid dual-permeability model (RDPM) and DDPM; (ii) test the sensitivity of the DDPM to the shrinking-swelling parameters; (iii) test the rationality of a “lighter” dynamic DPM (LDPM) only considering the proportion changes of each domain while neglecting the variation of hydraulic properties. The results showed that compared to the DDPM, the SDM overestimated the water content under low-rainfall intensity while underestimating the water content under high-intensity rainfall and failed to capture the early increase of water content in deep soils induced by PF-DC. The RDPM greatly overestimated the total water content and water storage capacity of the crack domain, which was not suggested to be used in the surface runoff or flood forecast. The DDPM is overall not sensitive to the shrinking-swelling parameters, indicative of relatively loose accuracy requirements in measuring the soil shrinking-swelling parameters. The LDPM can be a tentative alternative option for the DDPM, but it is better not to use it to evaluate the surface runoff or use it under long-term extreme drought. In conclusion, the prediction errors without considering crack evolution and variation of hydraulic properties of each domain (RDPM) are the highest, then followed by the only considering crack evolution (LDPM) and uncertainties of shrinking-swelling parameters.","Desiccation cracks; Dual-permeability model; Dynamic changes; Numerical experiments; Preferential flow","en","journal article","","","","","","","","","","","Water Resources","","",""
"uuid:4c515da8-6d44-45d9-bf8a-5c80b1a10eae","http://resolver.tudelft.nl/uuid:4c515da8-6d44-45d9-bf8a-5c80b1a10eae","Engineered biochemical cues of regenerative biomaterials to enhance endogenous stem/progenitor cells (ESPCs)-mediated articular cartilage repair","Zhou, Liangbin (The Hong Kong Polytechnic University; Chinese University of Hong Kong); Xu, J. (Erasmus MC); Schwab, Andrea (Erasmus MC); Tong, Wenxue (Chinese University of Hong Kong); Zheng, Lizhen (Chinese Academy of Sciences; Chinese University of Hong Kong); Li, Zhuo (Chinese University of Hong Kong); Xu, Shunxiang (Chinese University of Hong Kong); van Osch, G.J.V.M. (TU Delft Biomaterials & Tissue Biomechanics; Erasmus MC); Wen, Chunyi (The Hong Kong Polytechnic University); Qin, Ling (Chinese Academy of Sciences; Chinese University of Hong Kong)","","2023","As a highly specialized shock-absorbing connective tissue, articular cartilage (AC) has very limited self-repair capacity after traumatic injuries, posing a heavy socioeconomic burden. Common clinical therapies for small- to medium-size focal AC defects are well-developed endogenous repair and cell-based strategies, including microfracture, mosaicplasty, autologous chondrocyte implantation (ACI), and matrix-induced ACI (MACI). However, these treatments frequently result in mechanically inferior fibrocartilage, low cost-effectiveness, donor site morbidity, and short-term durability. It prompts an urgent need for innovative approaches to pattern a pro-regenerative microenvironment and yield hyaline-like cartilage with similar biomechanical and biochemical properties as healthy native AC. Acellular regenerative biomaterials can create a favorable local environment for AC repair without causing relevant regulatory and scientific concerns from cell-based treatments. A deeper understanding of the mechanism of endogenous cartilage healing is furthering the (bio)design and application of these scaffolds. Currently, the utilization of regenerative biomaterials to magnify the repairing effect of joint-resident endogenous stem/progenitor cells (ESPCs) presents an evolving improvement for cartilage repair. This review starts by briefly summarizing the current understanding of endogenous AC repair and the vital roles of ESPCs and chemoattractants for cartilage regeneration. Then several intrinsic hurdles for regenerative biomaterials-based AC repair are discussed. The recent advances in novel (bio)design and application regarding regenerative biomaterials with favorable biochemical cues to provide an instructive extracellular microenvironment and to guide the ESPCs (e.g. adhesion, migration, proliferation, differentiation, matrix production, and remodeling) for cartilage repair are summarized. Finally, this review outlines the future directions of engineering the next-generation regenerative biomaterials toward ultimate clinical translation.","Articular cartilage (AC) repair; Biochemical cues; Endogenous stem/progenitor cells (ESPCs); Regenerative biomaterials","en","review","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:16283eaf-fd25-4b1c-96a8-66567cad851c","http://resolver.tudelft.nl/uuid:16283eaf-fd25-4b1c-96a8-66567cad851c","Cardiac q-space trajectory imaging by motion-compensated tensor-valued diffusion encoding in human heart in vivo","Teh, Irvin (University of Leeds); Shelley, David (University of Leeds); Boyle, J.H. (TU Delft Emerging Materials); Zhou, Fenglei (University College London (UCL); Astrea Bioseparation, Comberton); Poenar, Ana Maria (University of Leeds); Sharrack, Noor (University of Leeds); Foster, Richard J. (University of Leeds); Yuldasheva, Nadira Y. (University of Leeds); Parker, Geoff J.M. (University College London (UCL); Bioxydyn Limited, Manchester)","","2023","Purpose: Tensor-valued diffusion encoding can probe more specific features of tissue microstructure than what is available by conventional diffusion weighting. In this work, we investigate the technical feasibility of tensor-valued diffusion encoding at high b-values with q-space trajectory imaging (QTI) analysis, in the human heart in vivo. Methods: Ten healthy volunteers were scanned on a 3T scanner. We designed time-optimal gradient waveforms for tensor-valued diffusion encoding (linear and planar) with second-order motion compensation. Data were analyzed with QTI. Normal values and repeatability were investigated for the mean diffusivity (MD), fractional anisotropy (FA), microscopic FA (μFA), isotropic, anisotropic and total mean kurtosis (MKi, MKa, and MKt), and orientation coherence (Cc). A phantom, consisting of two fiber blocks at adjustable angles, was used to evaluate sensitivity of parameters to orientation dispersion and diffusion time. Results: QTI data in the left ventricular myocardium were MD = 1.62 ± 0.07 μm2/ms, FA = 0.31 ± 0.03, μFA = 0.43 ± 0.07, MKa = 0.20 ± 0.07, MKi = 0.13 ± 0.03, MKt = 0.33 ± 0.09, and Cc = 0.56 ± 0.22 (mean ± SD across subjects). Phantom experiments showed that FA depends on orientation dispersion, whereas μFA was insensitive to this effect. Conclusion: We demonstrated the first tensor-valued diffusion encoding and QTI analysis in the heart in vivo, along with first measurements of myocardial μFA, MKi, MKa, and Cc. The methodology is technically feasible and provides promising novel biomarkers for myocardial tissue characterization.","cardiac microstructure; diffusion tensor imaging; motion-compensated diffusion encoding; q-space trajectory imaging; tensor-valued diffusion encoding; tissue characterization","en","journal article","","","","","","","","","","","Emerging Materials","","",""
"uuid:d5e757b9-f084-43dd-9e00-8dad372190ae","http://resolver.tudelft.nl/uuid:d5e757b9-f084-43dd-9e00-8dad372190ae","Cationic Effects on Photo- and X-ray Radioluminescence of K3RE(PO4)2:Ce3+/Pr3+ (RE = La, Gd, and Y) Phosphors toward X-ray Detection","Ou, Yiyi (Sun Yat-sen University); Zhou, Weijie (Sun Yat-sen University); Dorenbos, P. (TU Delft RST/Luminescence Materials); Liang, Hongbin (Sun Yat-sen University)","","2023","Cationic tuning for lanthanide (Ce3+/Pr3+)-activated inorganic phosphors with stable, efficient, and fast-decay 5d-4f emissions has emerged as an important strategy toward the continuing pursuit of superior scintillators. The in-depth understanding of the cationic effects on photo- and radioluminescence of lanthanides Ce3+ and Pr3+ centers is requisite for the rational cationic tuning. Here, we perform a systematic study on the structure and photo- and X-ray radioluminescence properties of K3RE(PO4)2:Ce3+/Pr3+ (RE = La, Gd, and Y) phosphors to elucidate the underlying cationic effects on their 4f-5d luminescence. By using the Rietveld refinements, low-temperature synchrotron-radiation vacuum ultraviolet-ultraviolet spectra, vibronic coupling analyses, and vacuum-referred binding energy schemes, the origins of lattice parameter evolutions, 5d excitation energies, 5d emission energies, and Stokes shifts as well as good emission thermal stabilities of K3RE(PO4)2:Ce3+ systems are revealed. In addition, the correlations of Pr3+ luminescence to Ce3+ in the same sites are also discussed. Finally, the X-ray excited luminescence manifests that the K3Gd(PO4)2:1%Ce3+ sample possesses a light yield of ∼10,217 photons/MeV, indicating its potentiality toward X-ray detection application. These results deepen the understanding of cationic effects on Ce3+ and Pr3+ 4f-5d luminescence and inspire the inorganic scintillator development.","","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-10-05","","","RST/Luminescence Materials","","",""
"uuid:5683d13d-c469-45e0-a15c-a8b5b7337153","http://resolver.tudelft.nl/uuid:5683d13d-c469-45e0-a15c-a8b5b7337153","Effects of phosphate addition on the removal of disinfection by-product formation potentials by biological activated carbon filtration","Wang, Feifei (Shanghai University); Hua, Yulin (Shanghai University); Pan, Jiazheng (Shanghai University); Zhou, Jie (Shanghai University); Hea, Chiquan (Shanghai University); Hofman, J.A.M.H. (University of Bath); Chu, Wenhai (Tongji University); van der Hoek, J.P. (TU Delft Sanitary Engineering; Waternet)","","2023","In drinking water treatment plants (DWTPs), the widely used biological activated carbon filters (BACFs), as the last barrier before disinfection, can remove dissolved organic matter (DOM) known as precursors of disinfection by-products (DBPs). Whether phosphate addition can improve water purification and DBP control of BACFs is still controversial. This study investigated short-term and long-term effects of phosphate addition on controlling DBP formation potentials (FPs) by BACFs via column and batch experiments. The BAC columns presented good water purification performance: they removed around 50 % DOM, nearly all fulvic acid-likes and humic acid-likes as well as 5 %–70 % chlor(am)innated THM4, HAA9 and HAN4 FPs (except chloraminated THM4 FPs), which was mainly contributed by aerobic bacteria not anoxic bacteria. Phosphate addition within 7–14 days further improved removals of DOM, aromatic organics, fluorescence fractions in DOM as well as HAA9 and HAN4 FPs (especially TCAA FP and TCAN FP) to different extent. However, this improvement did not last longer, and removals of DOM, aromatic organics, two fluorescence fractions (soluble microbial byproduct-likes and humic acid-likes) and DBP FPs decreased despite long-term phosphate addition. Oxic and anoxic batch experiments showed that the positive response of water purification to short-term phosphate addition was also mainly attributed to aerobic bacteria and not to anoxic bacteria. For example, the former decreased DOM and DBP FPs, while the latter increased protein- and tryptophan-like substances as well as chloraminated THM4 FPs. Phosphate addition resulted in EPS increase in anoxic reactors and decrease in oxic reactors. These results indicated that a high dissolved oxygen in BACFs may be helpful for water purification and DBP control. Overall, short-term phosphate addition into phosphorus-limited water is beneficial for BACFs to control DBPs while long-term addition has no effect. Therefore, an intermittent phosphate addition into BACFs is suggested to control DBPs in DWTPs.","Anoxic condition; Chloramination; Chlorination; Disinfection by-products; Oxic condition; Phosphate","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-10-20","","","Sanitary Engineering","","",""
"uuid:16b3989a-cea5-46dd-94ea-4e1758b2b3cb","http://resolver.tudelft.nl/uuid:16b3989a-cea5-46dd-94ea-4e1758b2b3cb","Metaverse for Connected and Automated Vehicles and Intelligent Transportation Systems [From the Guest Editors]","Zhou, Pengyuan (University of Science and Technology of China); Lee, Lik Hang (The Hong Kong Polytechnic University); Liu, Zhi (University of Electro-Communication); Qiu, Hang (University of California); Braud, Tristan (The Hong Kong University of Science and Technology); Ding, Aaron Yi (TU Delft Information and Communication Technology); Tarkoma, Sasu (University of Helsinki); Hui, Pan (The Hong Kong University of Science and Technology)","","2023","The metaverse aims to blur the boundary between the physical world and digital content. To achieve this goal, the metaverse relies heavily on extended reality (XR), the Internet of Things, and communication technologies. Concurrently, connected vehicles and intelligent transportation systems (ITSs) are envisioned as the future paradigm of driving and becoming reality thanks to increasingly powerful onboard vehicular processing capacity and advanced vehicle-to-everything networking technologies.","","en","review","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-06-28","","","Information and Communication Technology","","",""
"uuid:89517b06-0356-41c2-a01f-06aa80335777","http://resolver.tudelft.nl/uuid:89517b06-0356-41c2-a01f-06aa80335777","Deep learning-based design model for suction caissons on clay","Yin, Xilin (Student TU Delft); Wang, H. (TU Delft Geo-engineering; Norwegian Geotechnical Institute); Pisano, F. (TU Delft Geo-engineering); Gavin, Kenneth (TU Delft Geo-engineering); Askarinejad, A. (TU Delft Geo-engineering); Zhou, Hongpeng (The University of Manchetser)","","2023","Predicting the non-linear loading response is the key to the design of suction caissons. This paper presents a systematic study to explore the applicability of deep learning techniques in foundation design. Firstly, a series of three-dimensional finite element simulations was performed, covering a wide range of embedment ratios and different loading directions, to provide training data for the deep neural network (DNN) model. Then, hyper-parameter tuning was performed and it is found that the basic Fully-Connected (FC) neural network model is sufficient to capture the non-linear response of suction caissons with excellent accuracy and robustness. Furthermore, the optimized FC neural network model was also successfully applied to a database of suction caissons in sand, demonstrating its broad applicability. By comparing three typical DNNs, i.e., FC, Convolutional Neural Network (CNN) and Long Short-Term Memory (LSTM), it was observed that the FC neural network model excels over others in terms of simplicity, efficiency and accuracy. More importantly, by looking into the model's generalization performance, the FC neural network model can also identify the change in foundation failure mechanisms. This study demonstrates the DNN's powerful mapping ability and its potential for future use in offshore foundation design.","Caisson foundation; Deep learning; Load–displacement relationship; Numerical modelling","en","journal article","","","","","","","","","","","Geo-engineering","","",""
"uuid:65309414-5e39-42f0-8567-420df97afd2c","http://resolver.tudelft.nl/uuid:65309414-5e39-42f0-8567-420df97afd2c","Sustainable Sources of Raw Materials for Additive Manufacturing of Bone-Substituting Biomaterials","Putra, N.E. (TU Delft Biomaterials & Tissue Biomechanics); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2023","The need for sustainable development has never been more urgent, as the world continues to struggle with environmental challenges, such as climate change, pollution, and dwindling natural resources. The use of renewable and recycled waste materials as a source of raw materials for biomaterials and tissue engineering is a promising avenue for sustainable development. Although tissue engineering has rapidly developed, the challenges associated with fulfilling the increasing demand for bone substitutes and implants remain unresolved, particularly as the global population ages. This review provides an overview of waste materials, such as eggshells, seashells, fish residues, and agricultural biomass, that can be transformed into biomaterials for bone tissue engineering. While the development of recycled metals is in its early stages, the use of probiotics and renewable polymers to improve the biofunctionalities of bone implants is highlighted. Despite the advances of additive manufacturing (AM), studies on AM waste-derived bone-substitutes are limited. It is foreseeable that AM technologies can provide a more sustainable alternative to manufacturing biomaterials and implants. The preliminary results of eggshell and seashell-derived calcium phosphate and rice husk ash-derived silica can likely pave the way for more advanced applications of AM waste-derived biomaterials for sustainably addressing several unmet clinical applications.","3D printing of implants; additive manufacturing; orthopedic biomaterials; sustainability","en","review","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:b16f042c-06ef-4b71-84ea-f266c42e4ee2","http://resolver.tudelft.nl/uuid:b16f042c-06ef-4b71-84ea-f266c42e4ee2","Erratum: Electrical characteristics and photodetection mechanism of TiO2/AlGaN/GaN heterostructure-based ultraviolet detectors with a Schottky junction (J. Mater. Chem. C (2023) 11 (1704–1713) DOI: 10.1039/D2TC04491A)","Zhan, Teng (Chinese Academy of Sciences; University of Chinese Academy of Sciences); Sun, Jianwen (Tsinghua University); Feng, Tao (Chinese Academy of Sciences; University of Chinese Academy of Sciences); Zhang, Yulong (Tsinghua University); Zhou, Binru (Chinese Academy of Sciences; University of Chinese Academy of Sciences); Zhang, Banghong (Chinese Academy of Sciences; University of Chinese Academy of Sciences); Wang, Junxi (Chinese Academy of Sciences; University of Chinese Academy of Sciences); Sarro, Pasqualina M (TU Delft Electronic Components, Technology and Materials); Zhang, Kouchi (TU Delft Electronic Components, Technology and Materials)","","2023","The authors regret an error in the abstract of the published article: the text ‘‘(i) the Schottky emission mechanism at a low reverse voltage (0–1 V) before the current is fully turned on.’’ should be changed to ‘‘(i) the Schottky emission mechanism at a low reverse voltage (0 to 1 V) before the current is fully turned on.’’ This change does not affect the main conclusions of the manuscript. The authors would like to apologize for any inconvenience caused. The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.","","en","journal article","","","","","","","","","","","Electronic Components, Technology and Materials","","",""
"uuid:643ae557-8981-4965-9c88-bdaae0181490","http://resolver.tudelft.nl/uuid:643ae557-8981-4965-9c88-bdaae0181490","Liveness Checking of the HotStuff Protocol Family","Decouchant, Jérémie (TU Delft Data-Intensive Systems); Kulahcioglu Ozkan, Burcu (TU Delft Software Engineering); Zhou, Yanzhuo (Student TU Delft)","Ceballos, Cristina (editor)","2023","Byzantine consensus protocols aim at maintaining safety guarantees under any network synchrony model and at providing liveness in partially or fully synchronous networks. However, several Byzantine consensus protocols have been shown to violate liveness properties under certain scenarios. Existing testing methods for checking the liveness of consensus protocols check for time-bounded liveness violations, which generate a large number of false positives. In this work, for the first time, we check the liveness of Byzantine consensus protocols using the temperature and lasso detection methods, which require the definition of ad-hoc system state abstractions. We focus on the HotStuff protocol family that has been recently developed for blockchain consensus. In this family, the HotStuff protocol is both safe and live under the partial synchrony assumption, while the 2-Phase Hotstuff and Sync HotStuff protocols are known to violate liveness in subtle fault scenarios. We implemented our liveness checking methods on top of the Twins automated unit test generator to test the HotStuff protocol family. Our results indicate that our methods successfully detect all known liveness violations and produce fewer false positives than the traditional time-bounded liveness checks.","Byzantine consensus; Hotstuff protocols; Liveness checking; Lasso detection; Testing","en","conference paper","IEEE","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-06-21","","","Data-Intensive Systems","","",""
"uuid:cd33c3c4-60d8-4e12-80f1-fbc67e2c26fa","http://resolver.tudelft.nl/uuid:cd33c3c4-60d8-4e12-80f1-fbc67e2c26fa","Peroxygenase-Catalysed Sulfoxidations in Non-Aqueous Media","Li, Huanhuan (Xi’an Jiaotong University; Chinese Academy of Sciences); Shen, Qianqian (Xi’an Jiaotong University; Chinese Academy of Sciences); Zhou, Xiaoying (Chinese Academy of Sciences); Duan, Peigao (Xi’an Jiaotong University); Hollmann, F. (TU Delft BT/Biocatalysis); Huang, Yawen (Chinese Academy of Sciences); Zhang, Wuyuan (Chinese Academy of Sciences)","","2023","Chiral sulfoxides are valuable building blocks in asymmetric synthesis. However, the biocatalytic synthesis of chiral sulfoxides is still challenged by low product titres. Herein, we report the use of peroxygenase as a catalyst for asymmetric sulfoxidation under non-aqueous conditions. Upon covalent immobilisation, the peroxygenase showed stability and activity under neat reaction conditions. A large variety of sulfides was converted into chiral sulfoxides in very high product concentration with moderate to satisfactory optical purity (e. g. 626 mM of (R)-methyl phenyl sulfoxide in approx. 89 % ee in 48 h). Further polishing of the ee value via cascading methionine reductase A (MsrA) gave>99 % ee of the sulfoxide. The robustness of the enzymes and high product titer is superior to the state-of-the-art methodologies. Gram-scale synthesis has been demonstrated. Overall, we demonstrated a practical and facile catalytic method to synthesize chiral sulfoxides.","Asymmetric sulfoxidation; Biocatalysis; Cascade; Enzyme Immobilisation; Peroxygenase","en","journal article","","","","","","","","","","","BT/Biocatalysis","","",""
"uuid:1456c50d-8c88-48cc-a5be-c97220466c7c","http://resolver.tudelft.nl/uuid:1456c50d-8c88-48cc-a5be-c97220466c7c","Direct Evidence of Salinity Difference Effect on Water Transport in Oil: Pore-Scale Mechanisms","Yan, L. (TU Delft Reservoir Engineering; Universiteit Utrecht); Golestan, Mohammad Hossein (Norwegian University of Science and Technology (NTNU)); Zhou, Wenyu (Norwegian University of Science and Technology (NTNU)); Hassanizadeh, S. Majid (Universiteit Utrecht; University of Stuttgart); Berg, Carl Fredrik (Norwegian University of Science and Technology (NTNU)); Raoof, Amir (Universiteit Utrecht)","","2023","Low salinity water flooding is a common technique for enhancing oil recovery; however, the mechanism behind the low-salinity effect, positive or negative, is still not fully understood. In the proposed mechanisms, osmosis and emulsification are considered as two potential reasons for explaining the oil remobilization, but the specific contributions on the remobilization are not well studied at pore-scale. In this article, we performed a series of microfluidic experiments to investigate the movement of constrained oil between invading low-salinity brine and residual high-salinity brine. We find that various salinity contrasts over oil films cause different water fluxes through the oil and swelling areas of the trapped brine, resulting in the relocation of oil phases within the pore spaces. A higher salinity contrast (1.7-170 g/L salt concentrations) provides a faster water penetration in oil phases. In the presence of an oil-soluble surfactant, spontaneous emulsification occurs at the interface of low-salinity brine/oil, which enhances almost 100 times the water flux in two oil phases (n-heptane and n-dodecane). We directly observe pore-scale spontaneous emulsification at the low-salinity brine/oil interface but not at the high-salinity brine/oil interface. Furthermore, two scenarios for explaining water transport through the oil phase are proposed: water diffusion due to chemical potential gradient and water transport via reverse micelle or microemulsions movement.","","en","journal article","","","","","","","","","","","Reservoir Engineering","","",""
"uuid:295126a6-7d1c-436f-8b84-505e0f5fc429","http://resolver.tudelft.nl/uuid:295126a6-7d1c-436f-8b84-505e0f5fc429","Road performance evaluation of prestressed high-strength concrete pile waste powder as alternative filler in asphalt concrete","Tu, Botao (Guangdong Hongye Building Materials Technology Co., Ltd.); Yang, Xinkui (Wuhan University of Technology); Xu, S. (TU Delft Materials and Environment; Wuhan University of Technology); Zhao, Zenggang (Wuhan University of Technology); Zhou, Yuheng (Wuhan University of Technology); Jiang, Jian (Shenzhen Sez Construction Group Co., Ltd.); Fan, Lulu (Shenzhen Sez Construction Group Co., Ltd.); Tu, Liangliang (Shenzhen Sez Construction Group Co., Ltd.)","","2023","As a kind of solid waste, using Prestressed High-Strength Concrete Pile Waste Concrete (PPWC) as the replacement for limestone filler in asphalt concrete can not only reduce the accumulation of PPWC and increase its utilization but also avoid the increased road construction costs and environmental degradation associated with limestone mining. This study aims to investigate the effect of using PPWC filler to replace limestone filler on the road performance of asphalt concrete. Firstly, PPWC was ground into filler particles with a diameter less than 0.075 mm. The particle characteristics such as surface morphology, particle size distribution and chemical composition of PPWC filler and limestone filler were compared. Then, PPWC filler was used to replace limestone filler with different volume fractions to prepare asphalt concrete, and the water damage resistance, high-temperature rutting resistance, low-temperature crack resistance, fatigue resistance and adhesion performance of asphalt concrete were tested. The results showed that PPWC filler has a smaller particle size and rougher surface than limestone filler, and it contains Ca(OH)2 produced by hydration. The addition of PPWC filler can effectively improve the mechanical properties of asphalt concrete without reducing its water damage resistance. PPWC filler can improve the high-temperature rutting resistance and low-temperature crack resistance of asphalt concrete, but reduce its low-temperature fatigue resistance. The low content of PPWC filler will enhance the adhesion between asphalt mortar and aggregate. However, when the content of PPWC filler exceeds 50%, Ca (OH)2 in PPWC will reduce the adhesion between acid asphalt mortar and alkaline basalt aggregate. Therefore, the use of PPWC as filler in asphalt mixtures provides a reliable solution for the sustainable development of road materials.","asphalt concrete; filler; particle characteristics; PHC pile waste concrete; road performance","en","journal article","","","","","","","","","","","Materials and Environment","","",""
"uuid:34a60ef1-ec71-49e5-8593-eadda560bdf0","http://resolver.tudelft.nl/uuid:34a60ef1-ec71-49e5-8593-eadda560bdf0","Transversal optical singularity induced precision measurement of step-nanostructures","Dou, X. (TU Delft ImPhys/Pereira group; Shenzhen University); Zhou, Jiakang (Shenzhen University); Zhang, Yuquan (Shenzhen University); Min, Changjun (Shenzhen University); Pereira, S.F. (TU Delft ImPhys/Pereira group); Yuan, Xiaocong (Shenzhen University)","","2023","Optical singularities indicate zero-intensity points in space where parameters, such as phase, polarization, are undetermined. Vortex beams such as the Laguerre–Gaussian modes are characterized by a phase factor eilθ, and contain a phase singularity in the middle of its beam. In the case of a transversal optical singularity (TOS), it occurs perpendicular to the propagation, and its phase integral is 2π in nature. Since it emerges within a nano-size range, one expects that TOSs could be sensitive in the light-matter interaction process and could provide a great possibility for accurate determination of certain parameters of nanostructure. Here, we propose to use TOSs generated by a three-wave interference to illuminate a step nanostructure. After interaction with the nanostructure, the TOS is scattered into the far field. The scattering direction can have a relation with the physical parameters of the nanostructure. We show that by monitoring the spatial coordinates of the scattered TOS, its propagation direction can be determined, and as consequence, certain physical parameters of the step nanostructure can be retrieved with high precision.","","en","journal article","","","","","","","","","","","ImPhys/Pereira group","","",""
"uuid:a9c9911a-8695-4cfd-ac27-1eeb19af59b5","http://resolver.tudelft.nl/uuid:a9c9911a-8695-4cfd-ac27-1eeb19af59b5","Damage pattern recognition for corroded beams strengthened by CFRP anchorage system based on acoustic emission techniques","Pan, Tanbo (Tongji University); Zheng, Yonglai (Tongji University); Zhou, Y. (TU Delft Concrete Structures); Luo, Wenbin (Tongji University); Xu, Xubing (Tongji University); Hou, Chenyu (Tongji University); Zhou, Yujue (Tongji University; Sanming University)","","2023","This study presents a damage pattern recognition approach for corroded steel beams strengthened by CFRP anchorage system based on acoustic emission clustering analysis. The proposed method includes four steps: acoustic emission signal acquisition, feature extraction, clustering analysis, and damage pattern recognition. Four corroded beams with different corrosion levels and strengthening schemes were tested under four-point bending loading. The acoustic emission signals were collected during the loading process and analyzed using Gaussian mixture model clustering method. The results showed that the collected AE data were analyzed using clustering analysis, successfully distinguishing the distinct damage patterns associated with each mode. The AE signals exhibited distinct characteristics for different damage modes: concrete matrix damage had high-frequency and low-energy characteristics, CFRP-matrix debonding showed intermediate values for all parameters, and CFRP tearing had longer durations, lower peak frequencies, and high-energy characteristics. Besides, the study identified three stages of the damage process: an initial stage with fewer low-intensity AE signals, a damage development stage characterized by an increase in concrete-matrix damage and CFRP – matrix debonding signals, and a continuous damage growth stage with significant AE signals associated with three damage modes. Furthermore, the degree of corrosion significantly influenced the cumulative AE energy of damage modes. Lower degrees of corrosion led to higher cumulative energy from concrete matrix damage and CFRP-matrix debonding. These findings provide valuable insights for understanding the damage evolution and failure mechanisms of CFRP-strengthened corroded beams. The use of AE techniques for damage pattern recognition can enhance the evaluation and design of CFRP anchorage systems, leading to more effective rehabilitation strategies for corroded structures.","Acoustic emission; CFRP anchorage system; Damage mechanism; Damage pattern recognition","en","journal article","","","","","","","","","","","Concrete Structures","","",""
"uuid:4a25e88a-d481-42d2-82e2-8799c06b5361","http://resolver.tudelft.nl/uuid:4a25e88a-d481-42d2-82e2-8799c06b5361","A geographic information system-based large scale visibility assessment tool for multi-criteria photovoltaic planning on urban building roofs","Zhou, Y. (TU Delft Photovoltaic Materials and Devices); Wilmink, D. (Student TU Delft); Zeman, M. (TU Delft Photovoltaic Materials and Devices); Isabella, O. (TU Delft Photovoltaic Materials and Devices); Ziar, H. (TU Delft Photovoltaic Materials and Devices)","","2023","Integration of photovoltaics (PV) into the urban environment will play a major role in the energy transition. However, installing PV systems on building roofs can be challenging, particularly for monumental buildings with strict architectural and social value restrictions. Assessing roof surface visibility is, therefore, key to finding as much permitted roof surface area as possible that may be used for PV installation. In this study, a GIS-based large-scale visibility assessment tool is developed that can assist in evaluating roof visibility, using LiDAR, road networks, and cadastral data as inputs. The tool delivers multi-level outputs, including maps of roof binary visibility, roof visual amplitude, roof PV system layout, roof PV system AC yield, and roof PV module visibility. After optimization, an average speed of 0.12 s/m2 is achieved. For each roof surface, an additional sensitivity analysis has been conducted. This step determines the optimal values for two visibility analysis parameters: assessment range and observer spacing, balancing the computational demand and result accuracy. Application of this workflow to the monumental buildings on the TU Delft campus revealed that approximately 2.68 GWh/year of electricity could be harvested from imperceptible PV modules, while an additional 0.42 GWh/year of energy is attributed to PV modules with medium visibility, and 0.37 GWh/year of energy is associated with PV modules with high visibility. This modeling workflow supports the multi-criteria decision-making process for urban roof PV planning.","GIS spatial analysis; Multi-criteria decision making; Rooftop PV; Urban planning; Visual impact","en","journal article","","","","","","","","","","","Photovoltaic Materials and Devices","","",""
"uuid:58cbb288-c334-47c6-b310-5013ab08e67f","http://resolver.tudelft.nl/uuid:58cbb288-c334-47c6-b310-5013ab08e67f","Deep residual learning for acoustic emission source localization in A steel-concrete composite slab","Zhou, Y. (TU Delft Concrete Structures); Liang, M. (TU Delft Materials and Environment); Yue, X. (TU Delft Electronic Instrumentation)","","2023","Large errors can be introduced in traditional acoustic emission (AE) source localization methods using extracted signal features such as arrival time difference. This issue is obvious in the case of irregular structural geometries, complex composite structure types or presence of cracks in wave travel paths. In this study, based on a novel deep learning algorithm called deep residual network (DRN), a structural health monitoring (SHM) strategy is proposed for AE source localization through classifying and recognizing the AE signals generated in different sub-regions of critical areas in structures. Hammer hits and pencil-leak break (PLB) tests were carried out on a steel-concrete composite slab specimen to register time-domain AE signals under multiple structural damage conditions. The obtained time-domain AE signals were then converted into time-frequency images as inputs for the proposed DRN architecture using the continuous wavelet transform (CWT). The DRNs were trained, validated and tested by AE signals generated from different source types at various damage states of the slab specimen. The proposed DRN architecture shows an effective potential for AE source localization. The results show that the DRN models pre-trained by the AE signals obtained in the undamaged specimen are able to accurately classify and identify the locations of different types of AE sources with 3–4.5 cm intervals even when multiple cracks with widths up to 4–6 mm are present in the wave travel paths. Moreover, the influence factors on the model performance are investigated, including structural damage conditions, sensor-to-source distances and AE sensor mounting positions; in accordance with the parametric analyses, recommendations are proposed for the engineering application of the proposed SHM strategy.","Acoustic emission (AE) source localization; Deep residual network (DRN); Image classification; Steel-concrete composite structures; Wave propagation in damaged structures","en","journal article","","","","","","","","","","","Concrete Structures","","",""
"uuid:4329b194-7c01-4ecd-849e-8ff3148450f9","http://resolver.tudelft.nl/uuid:4329b194-7c01-4ecd-849e-8ff3148450f9","A conflict cluster-based method for collision avoidance decision-making in multi-ship encounter situations","Liu, Kezhong (Wuhan University of Technology; Hubei Key Laboratory of Inland Shipping Technology); Wu, Xiaolie (Wuhan University of Technology; Hubei Key Laboratory of Inland Shipping Technology); Zhou, Y. (TU Delft Rivers, Ports, Waterways and Dredging Engineering; Wuhan University of Technology); Yuan, Zhitao (Wuhan University of Technology; Hubei Key Laboratory of Inland Shipping Technology); Yang, Xing (Wuhan University of Technology; Hubei Key Laboratory of Inland Shipping Technology); Xin, Xuri (Wuhan University of Technology; Hubei Key Laboratory of Inland Shipping Technology); Zhuang, Sujie (Wuhan University of Technology)","","2023","During the process of collision avoidance, especially in a multi-ship encounter situation, the dynamic interactions among individual ships impose a significant impact on collision avoidance decision-making. It is imperative, therefore, that collision avoidance decisions are formulated with a comprehensive consideration of not only the current direct collision conflict but also the potential conflicts due to planned collision avoidance actions. To address this requirement, this paper proposes a dynamic conflict cluster detection method for collision avoidance decision-making in multi-ship encounters. The involved ships are clustered into stable temporal-dependent ship conflict groups taking into account both conflict connectivity and the potential spatiotemporal interactions originating from planned collision avoidance actions. The conflict cluster detection model is implemented within a framework to achieve hierarchical coordinated collision avoidance decision-making. By a simulation experiment of an 11-ship encounter, the proposed method successfully discerns the ships with conflicts and provides feasible collision avoidance decisions. Compared to the non-cluster collision avoidance methods, the proposed method generates the results with acceptable deviating distance and number of collision avoidance actions at minimum computation load. It has been demonstrated that the proposed method is both effective and efficient for officers on board and operators at Vessel Traffic Services centers in real-life navigation.","Collision avoidance; Conflict cluster detection; Decision-making; Multi-ship encounter","en","journal article","","","","","","","","","","","Rivers, Ports, Waterways and Dredging Engineering","","",""
"uuid:90f1dd5c-15b1-48f2-924e-bb7b86c422f8","http://resolver.tudelft.nl/uuid:90f1dd5c-15b1-48f2-924e-bb7b86c422f8","Continuous Fatty Acid Decarboxylation using an Immobilized Photodecarboxylase in a Membrane Reactor","Zhou, Jianle (South China University of Technology); Hollmann, F. (TU Delft BT/Biocatalysis); He, Qi (South China University of Technology); Chen, Wen (South China University of Technology); Ma, Yunjian (South China University of Technology); Wang, Yonghua (South China University of Technology; GuangdongYoumei Institute of Intelligent Bio-manufacturing Co. Ltd., v)","","2023","The realm of photobiocatalytic alkane biofuel synthesis has burgeoned recently; however, the current dearth of well-established and scalable production methodologies in this domain remains conspicuous. In this investigation, we engineered a modified form of membrane-associated fatty acid photodecarboxylase sourced from Micractinium conductrix (McFAP). This endeavour resulted in creating an innovative assembled photoenzyme-membrane (protein load 5 mg cm−2), subsequently integrated into an illuminated flow apparatus to achieve uninterrupted generation of alkane biofuels. Through batch experiments, the photoenzyme-membrane exhibited its prowess in converting fatty acids spanning varying chain lengths (C6–C18). Following this, the membrane-flow mesoscale reactor attained a maximum space-time yield of 1.2 mmol L−1 h−1 (C8) and demonstrated commendable catalytic proficiency across eight consecutive cycles, culminating in a cumulative runtime of eight hours. These findings collectively underscored the photoenzyme-membrane's capability to facilitate the biotransformation of diverse fatty acids, furnishing valuable benchmarks for the conversion of biomass via photobiocatalysis.","alkane biofuel; continuous photocatalysis; decarboxylation; photoenzyme-membrane; self-assembly","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-06-15","","","BT/Biocatalysis","","",""
"uuid:7492e91a-ea74-4ce2-8274-9a5f9eb36f01","http://resolver.tudelft.nl/uuid:7492e91a-ea74-4ce2-8274-9a5f9eb36f01","A tour-based multimodal mode choice model for impact assessment of new mobility concepts and mobility as a service","Zhou, H. (TNO; Universiteit van Amsterdam); Dorsman, J. L. (Universiteit van Amsterdam); Mandjes, M. (Universiteit Leiden; Universiteit van Amsterdam); Snelder, M. (TU Delft Transport and Planning; TNO)","","2023","Mobility as a Service (MaaS) and new mobility concepts mutually inspire each other, provide alternatives for the private car-oriented transport system as we know it, and will offer more mobility choices in a single journey than ever. This multitude of mobility choices however poses challenges in modeling the travelers’ mode choices in travel demand prediction models. To address these challenges, this paper develops a multimodal tour-based mode choice model as part of an activity-based demand model. By explicitly modeling access and egress modes, this choice model creates multimodal mode chain sets on a tour level based on restrictions with respect to personal vehicle ownership, MaaS subscription ownership and vehicle states, and subsequently makes mode choices for every traveler. For the creation of these mode chain sets, we introduce the concept of mode categorization. Seven mode categories are proposed, which include both private and shared mobility concepts. This categorization makes sure that modes are mutually sufficiently different in nature, so that reasonably unbiased mode chain choices can be made. Furthermore, the reduction to seven categories enables the study of large scenarios, while the introduced categories still represent new and already existing modes well. The potential of the model is illustrated by simulating travel demand in the Metropolitan region Rotterdam-The Hague. The results show that our model is capable of making plausible mode choices in the presence of MaaS and new mobility concepts, and can be used to assess the impact of mobility hubs where access and egress mode choice is important.","MaaS; Mode choice; Multimodal trips; New mobility concepts; Tour-based","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-05-27","","","Transport and Planning","","",""
"uuid:43d6ac40-1fff-4a8e-8864-7920731468a2","http://resolver.tudelft.nl/uuid:43d6ac40-1fff-4a8e-8864-7920731468a2","Association analysis of accident factors in petrochemical storage tank farms","Liu, Zhihao (Guangdong University of Technology); Zhou, Jianfeng (Guangdong University of Technology); Reniers, G.L.L.M.E. (TU Delft Safety and Security Science; Universiteit Antwerpen; Katholieke Universiteit Leuven)","","2023","In order to identify and clarify the association between the factors leading to accidents in a petrochemical tank area, this study analyzes investigation reports of 212 petrochemical tank farm accidents and combines this with the “association rule” mining and science related to complex networks. The main risk factors are determined and a risk factor data set is constructed; 75 association rules are extracted from the factor data set based on the Apriori algorithm. Then the obtained association rules are used to construct an accident factors network of the petrochemical storage tank area, and the topology characteristics of the network are further analyzed to reveal the importance of factors. Factors with large node degree, betweenness, and clustering coefficients are obtained, such as “violation of operating regulations”, “high concentration of flammable gas in the air”, “lack of experience and professional skills”, etc. These factors play an important role in the formation and development of accidents. The results also show that the accident cause network of the petrochemical storage tank area has a small average shortest path length and a large cluster coefficient, indicating a relatively close connection between the accident factors. The contributions of this study is not only extracting the hidden relationships among contributory factors to tank farm accidents using association analysis, but also revealing which factors are more important for the tank farm safety through the complex network.","Association rule mining; Complex networks; Important accident factors; Tank farm accidents","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-12-14","","","Safety and Security Science","","",""
"uuid:a6b2f9f5-2a85-46d3-92fd-a097f8a4367c","http://resolver.tudelft.nl/uuid:a6b2f9f5-2a85-46d3-92fd-a097f8a4367c","Mechanical and shape memory properties of NiTi triply periodic minimal surface structures fabricated by laser powder bed fusion","Sun, Lingqi (Huazhong University of Science and Technology); Chen, K. (TU Delft Biomechanical Engineering); Geng, Peng (Huazhong University of Science and Technology); Zhou, Yan (Huazhong University of Science and Technology); Wen, Shifeng (Huazhong University of Science and Technology); Shi, Yusheng (Huazhong University of Science and Technology)","","2023","Porous NiTi lattice structures are widely used in the manufacture of crucial components owing to their excellent shape memory effect, superelasticity, and high damping capacities. However, the specific strength and lightweight characteristics of porous NiTi lattice structures fabricated by conventional technologies are limited by unpredictability. In this work, three types of porous NiTi structures based on triply periodic minimal surface (TPMS) – Diamond, Gyroid, and Primitive – were designed and manufactured by the laser powder bed fusion (LPBF) additive manufacturing process. This work demonstrates LPBF is a feasible and efficient approach to fabricate highly accurate porous NiTi TPMS structures. Moreover, the influence of each of these structures on the mechanical and shape memory properties was investigated. Among the three structures, Gyroid had the smallest volume fraction deviation. Furthermore, the Diamond structure had the largest compressive modulus (782.82 MPa) and ultimate yield strength (163.14 MPa). The Gyroid and Primitive structures exhibit excellent elastic recovery deriving from high values of compressive modulus (662.44 MPa, and 703.29 MPa), and can maintain reliable structural robustness. The Primitive structure exhibited the lowest mechanical properties (37.80 MPa). During the cyclic compression test, Gyroid and Primitive show a smaller unrecovered strain than Diamond. Primitive shows the largest recovered strain during the heating process (6.98%). The higher mechanical flexibility of Primitive structure endows this structure with higher recovery ratio. During the direct compression test, the residual strain exhibits a positive correlation with the loading strain. All three structures exhibit good deformation recovery capability with a strain of 4%. At a strain of 12%, recovered strain during heating became the dominant factor in the recovery of the TPMS structure. Overall, porous NiTi TPMS structures are capable of reversible compressibility composed of rapid elastic recovery and controllable shape memory recovery. The unique performance of porous NiTi TPMS structure fabricated by LPBF renders it a highly efficiency energy-absorbing structure.","Laser powder bed fusion; NiTi alloy; Shape memory effect; Three-period minimum surface","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-01-05","","Biomechanical Engineering","","","",""
"uuid:bb98e55c-59ff-412c-af06-30e517dfa6a8","http://resolver.tudelft.nl/uuid:bb98e55c-59ff-412c-af06-30e517dfa6a8","Ultra-low-frequency radio astronomy observations from a Seleno-centric orbit: First results of the Longjiang-2 experiment","Yan, Jingye (Chinese Academy of Sciences; National Space Science Center; University of Chinese Academy of Sciences); Wu, Ji (National Space Science Center; University of Chinese Academy of Sciences); Gurvits, L. (TU Delft Astrodynamics & Space Missions; Joint Institute for VLBI ERIC); Wu, Lin (State Key Laboratory of Space Weather; Chinese Academy of Sciences; National Space Science Center; University of Chinese Academy of Sciences); Deng, Li (National Space Science Center); Zhao, Fei (National Space Science Center); Zhou, Li (National Space Science Center); Lan, Ailan (Chinese Academy of Sciences; National Space Science Center; University of Chinese Academy of Sciences); Fan, Wenjie (National Space Science Center)","","2023","This paper introduces the first results of observations with the Ultra-Long-Wavelength (ULW) —- Low Frequency Interferometer and Spectrometer (LFIS) on board the selenocentric satellite Longjiang-2. We present a brief description of the satellite and focus on the LFIS payload. The in-orbit commissioning confirmed a reliable operational status of the instrumentation. We also present results of a transition observation, which offers unique measurements on several novel aspects. We estimate the RFI suppression required for such a radio astronomy instrumentation at the Moon-distances from Earth as order of − 80 dB. We analyse a method of separating Earth- and satellite-originated radio frequency interference (RFI). It is found that the RFI level at frequencies lower than a few MHz is smaller than the receiver noise floor.","DSL; FLIS; Interferometric radiometer; Longjiang-2; Lunar orbit; Radio astronomy; Satellite array; Ultra-low frequencies","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-09-02","","","Astrodynamics & Space Missions","","",""
"uuid:68b6aff9-74b7-4373-8089-ed0e2e0c8c56","http://resolver.tudelft.nl/uuid:68b6aff9-74b7-4373-8089-ed0e2e0c8c56","A Strategy Inspired by the Cicada Shedding Its Skin for Synthesizing the Natural Material NaFe3S5·2H2O","Dai, Hanqing (Fudan University); Dai, Wenqing (Shanghai Jiao Tong University); Chen, Yuanyuan (Fudan University); Yan, Yukun (Fudan University); Zuo, Guangzheng (Fudan University); Hu, Zhe (Fudan University); Wei, Jinxin (Fudan University); Zhou, Wenjie (Fudan University); Zhang, Kouchi (TU Delft Electronic Components, Technology and Materials)","","2023","Sulfide minerals hold significant importance in both fundamental science and industrial advancement. However, certain natural sulfide minerals, such as NaFe3S5·2H2O (NFS), pose great challenges for exploitation and synthesis due to their high susceptibility to oxidation. To date, no successful precedent exists for synthesizing NFS. Here, a novel approach to synthesizing low-cost and pollution-free NFS with high stability using the high-pressure hydrothermal method based solely on knowledge of its chemical formula is presented. Moreover, an innovative strategy inspired by the cicada's molting process to develop unstable natural materials is proposed. The mechanical, thermal, optical, electrochemical, and magnetic properties of the NFS are thoroughly investigated. The storage of lithium, sodium, and potassium ions is primarily concentrated in the gap between (0 0 1) crystal planes. Additionally, as a catalyst for hydrogen evolution reaction (HER) at 10 mA cm−2, micron-sized NFS exhibits an excellent overpotential of 6.5 mV at 90 °C, surpassing those of reported HER catalysts of similar size. This research bridges the gap in the sulfide mineral family, overcomes limitations of the high-pressure hydrothermal method, and paves the way for future synthesis of natural minerals, lunar minerals, and Martian minerals.","catalyze; energy storage; NaFeS·2HO; sulfide mineral","en","journal article","","","","","","","","","","","Electronic Components, Technology and Materials","","",""
"uuid:345a4c40-612c-451e-8203-f8e104fd79fb","http://resolver.tudelft.nl/uuid:345a4c40-612c-451e-8203-f8e104fd79fb","A deep learning framework based on improved self-supervised learning for ground-penetrating radar tunnel lining inspection","Huang, Jian (China University of Geosciences, Wuhan); Yang, Xi (China University of Geosciences, Wuhan); Zhou, Feng (China University of Geosciences, Wuhan; Southern University of Science and Technology); Li, Xiaofeng (China University of Geosciences, Wuhan); Zhou, Bin (China Railway Southwest Research Institute Co. Ltd.); Lu, Song (China Railway Southwest Research Institute Co. Ltd.); Ivashov, Sergey (Bauman Moscow State Technical University); Giannakis, Iraklis (University of Aberdeen); Kong, Fannian (Norwegian Geotechnical Institute); Slob, E.C. (TU Delft Applied Geophysics and Petrophysics)","","2023","It is not practical to obtain a large number of labeled data to train a supervised learning network in tunnel lining nondestructive testing with ground-penetrating radar (GPR). To decrease the dependence of supervised learning on the number of labeled data, an improved self-supervised learning algorithm—self-attention dense contrastive learning (SA-DenseCL)—is proposed and incorporated with a mask region-convolution neural network (Mask R-CNN), which is trained by unlabeled and labeled GPR data. The proposed SA-DenseCL adds a self-attention-based relevant projection head to the DenseCL architecture of self-supervised learning, capturing the spatially continuing information between adjacent GPR traces. In the workflow, some unlabeled GPR images are used to pre-train the SA-DenseCL network for feature extraction and obtaining the backbone weights, which is superior to the conventional pre-training methods of supervised learning pre-trained by ImageNet images. The weights of the pre-trained backbone are then used to initialize the Mask R-CNN through transfer learning. Subsequently, a limited number of labeled GPR images are used to fine-tune the Mask R-CNN for automatically identifying the locations of the reinforcement bars and voids and estimating the secondary lining thickness. The experimental results show that the average precision reaches 96.70%, 81.04%, and 94.67% in identifying reinforcement bar locations, detecting void defects, and estimating secondary lining thickness, respectively, which outperform the conventional methods that use ImageNet-based supervised learning or GPR image-based DenseCL for initializing the Mask R-CNN backbone weights. It is observed that the improved self-supervised learning-based framework can improve the detection and estimation accuracy in GPR tunnel lining inspection.","","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-11-19","","","Applied Geophysics and Petrophysics","","",""
"uuid:29d9ea82-d723-44b1-94bb-f64c95631b6b","http://resolver.tudelft.nl/uuid:29d9ea82-d723-44b1-94bb-f64c95631b6b","Bio-inspired combinable self-powered soft device operating during the disintegration and reconstruction for next-generation artificial electric organs","Chen, Yuanyuan (Fudan University); Dai, Hanqing (Fudan University); Hu, Zhe (Fudan University); Wei, Jinxin (Fudan University); Zhou, Wenjie (Fudan University); Duan, Zhongtao (Fudan University); Cui, Zhongjie (Fudan University); Wei, Wei (Nanjing University of Posts and Telecommunications); Zhang, Kouchi (TU Delft Electronic Components, Technology and Materials)","","2023","Hydrogel materials have biocompatibility, flexibility, transparency, self-healing ability, adhesion with various substrates, anti-freeze ability, and high-temperature resistance. However, the existing hydrogel devices cannot continue to operate in the case of damage, and they cannot work during the repair period, which brings great challenges and threats to life safety. Herein, we have designed a bio-inspired combinable low-power device by imitating the generation of nerve signals whose components can be disassembled and can continue to operate during the period of reconstruction. And the mechanism and determinants of the above phenomena are revealed. The results indicate that this device can establish some information interaction relationships with the body or its surroundings to reflect and identify certain changes, implying that it will possess promising potential in feedback systems, power transformers, intelligence systems, soft robotics, wearable devices, implanted electronics with flexible characteristics matching biological tissues, etc.","Combinable ability; Disintegration; Hydrogel sensor array; Programmable intelligent identification model; Reconstruction; Self-powered sensors","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-10-23","","","Electronic Components, Technology and Materials","","",""
"uuid:fd0a7c06-3f8d-4131-a9cd-1dba103659df","http://resolver.tudelft.nl/uuid:fd0a7c06-3f8d-4131-a9cd-1dba103659df","Spatiotemporal Patterns in Land Use/Land Cover Observed by Fusion of Multi-Source Fine-Resolution Data in West Africa","Asenso Barnieh, Beatrice (International Research Center for Big Data for Sustainable Development Goals; Chinese Academy of Sciences; University of Energy and Natural Resources); Jia, Li (International Research Center for Big Data for Sustainable Development Goals; Chinese Academy of Sciences); Menenti, M. (TU Delft Optical and Laser Remote Sensing; Chinese Academy of Sciences); Yu, Le (Tsinghua University); Nyantakyi, Emmanuel Kwesi (University of Energy and Natural Resources); Kabo-Bah, Amos Tiereyangn (University of Energy and Natural Resources); Jiang, Min (Chinese Academy of Sciences); Zhou, Jie (Central China Normal University); Lv, Yunzhe (Chinese Academy of Sciences)","","2023","Land Use/Land Cover (LULC) change is a major global concern and a topic of scientific debate. In West Africa, the key trend among the changes of the past few years is the loss of natural vegetation related to changes in different LULC categories, e.g., water bodies, wetland, and bare soil. However, not all detected changes in these LULC categories are relevant for LULC change management intervention in a resource-constrained continent, as a massive change in the dominant LULC types may be due to errors in the LULC maps. Previous LULC change analysis detected large discrepancies in the existing LULC maps in Africa. Here, we applied an open and synergistic framework to update and improve the existing LULC maps for West Africa at five-year intervals from 1990 to 2020—updating them to a finer spatial resolution of 30 m. Next, we detected spatial–temporal patterns in past and present LULC changes with the intensity analysis framework, focusing on the following periods: 1990–2000, 2000–2010, and 2010–2020. A faster annual rate of overall transition was detected in 1990–2000 and 2010–2020 than in 2000–2010. We observed consistent increases in shrubland and grassland in all of the periods, which confirms the observed re-greening of rangeland in West Africa. By contrast, forestland areas experienced consistent decreases over the entire period, indicating deforestation and degradation. We observed a net loss for cropland in the drought period and net gains in the subsequent periods. The settlement category also gained actively in all periods. Net losses of wetland and bare land categories were also observed in all of the periods. We observed net gains in water bodies in the 1990–2000 period and net losses in the 2010–2020 period. We highlighted the active forestland losses as systematic and issued a clarion call for an intervention. The simultaneous active gross loss and gain intensity of cropland raises food security concerns and should act as an early warning sign to policy makers that the food security of marginal geographic locations is under threat, despite the massive expansion of cropland observed in this study area. Instead of focusing on the dynamics of all the LULC categories that may be irrelevant, the intensity analysis framework was vital in identifying the settlement category relevant for LULC change management intervention in West Africa, as well as a cost-effective LULC change management approach.","intensity analysis; natural vegetation; random transitions; spatial patterns; systematic transitions; West Africa","en","journal article","","","","","","","","","","","Optical and Laser Remote Sensing","","",""
"uuid:3cd9ff56-1f27-4cf8-89c1-74a815c23c1a","http://resolver.tudelft.nl/uuid:3cd9ff56-1f27-4cf8-89c1-74a815c23c1a","Intrinsic-Strain Engineering by Dislocation Imprint in Bulk Ferroelectrics","Zhuo, Fangping (Technische Universität Darmstadt); Zhou, Xiandong (Sichuan University); Gao, Shuang (Technische Universität Darmstadt); Dietrich, Felix (Technische Universität Darmstadt); Braga Groszewicz, P. (TU Delft RST/Storage of Electrochemical Energy); Fulanović, Lovro (Technische Universität Darmstadt); Breckner, Patrick (Technische Universität Darmstadt); Xu, Bai Xiang (Technische Universität Darmstadt); Kleebe, Hans Joachim (Technische Universität Darmstadt)","","2023","We report an intrinsic strain engineering, akin to thin filmlike approaches, via irreversible high-temperature plastic deformation of a tetragonal ferroelectric single-crystal BaTiO3. Dislocations well-aligned along the [001] axis and associated strain fields in plane defined by the [110]/[1¯10] plane are introduced into the volume, thus nucleating only in-plane domain variants. By combining direct experimental observations and theoretical analyses, we reveal that domain instability and extrinsic degradation processes can both be mitigated during the aging and fatigue processes, and demonstrate that this requires careful strain tuning of the ratio of in-plane and out-of-plane domain variants. Our findings advance the understanding of structural defects that drive domain nucleation and instabilities in ferroic materials and are essential for mitigating device degradation.","","en","journal article","","","","","","","","","","","RST/Storage of Electrochemical Energy","","",""
"uuid:5d1a2896-3467-4368-912b-16ee46ce1e41","http://resolver.tudelft.nl/uuid:5d1a2896-3467-4368-912b-16ee46ce1e41","Additive manufacturing of vascular stents","Li, Yageng (University of Science and Technology Beijing); Shi, Yixuan (University of Science and Technology Beijing); Lu, Yuchen (University of Science and Technology Beijing); Li, Xuan (University of Science and Technology Beijing); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics); Wang, Luning (University of Science and Technology Beijing)","","2023","With the advancement of additive manufacturing (AM), customized vascular stents can now be fabricated to fit the curvatures and sizes of a narrowed or blocked blood vessel, thereby reducing the possibility of thrombosis and restenosis. More importantly, AM enables the design and fabrication of complex and functional stent unit cells that would otherwise be impossible to realize with conventional manufacturing techniques. Additionally, AM makes fast design iterations possible while also shortening the development time of vascular stents. This has led to the emergence of a new treatment paradigm in which custom and on-demand-fabricated stents will be used for just-in-time treatments. This review is focused on the recent advances in AM vascular stents aimed at meeting the mechanical and biological requirements. First, the biomaterials suitable for AM vascular stents are listed and briefly described. Second, we review the AM technologies that have been so far used to fabricate vascular stents as well as the performances they have achieved. Subsequently, the design criteria for the clinical application of AM vascular stents are discussed considering the currently encountered limitations in materials and AM techniques. Finally, the remaining challenges are highlighted and some future research directions are proposed to realize clinically-viable AM vascular stents. Statement of significance: Vascular stents have been widely used for the treatment of vascular disease. The recent progress in additive manufacturing (AM) has provided unprecedented opportunities for revolutionizing traditional vascular stents. In this manuscript, we review the applications of AM to the design and fabrication of vascular stents. This is an interdisciplinary subject area that has not been previously covered in the published review articles. Our objective is to not only present the state-of-the-art of AM biomaterials and technologies but to also critically assess the limitations and challenges that need to be overcome to speed up the clinical adoption of AM vascular stents with both anatomical superiority and mechanical and biological functionalities that exceed those of the currently available mass-produced devices.","Additive manufacturing; Biological performance; Biomaterial; Mechanical property; Vascular stent","en","review","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:b47fe8b3-30bc-48d7-9174-ac99da1cfe6a","http://resolver.tudelft.nl/uuid:b47fe8b3-30bc-48d7-9174-ac99da1cfe6a","Combining Atomic Layer Deposition with Surface Organometallic Chemistry to Enhance Atomic-Scale Interactions and Improve the Activity and Selectivity of Cu-Zn/SiO2 Catalysts for the Hydrogenation of CO2 to Methanol","Zhou, Hui (ETH Zürich; Tsinghua University); Docherty, Scott R. (ETH Zürich); Phongprueksathat, N. (TU Delft ChemE/Catalysis Engineering); Chen, Zixuan (ETH Zürich); Bukhtiyarov, Andrey V. (Boreskov Institute of Catalysis SB RAS); Prosvirin, Igor P. (Boreskov Institute of Catalysis SB RAS); Safonova, Olga V. (Paul Scherrer Institut); Urakawa, A. (TU Delft ChemE/Catalysis Engineering); Copéret, Christophe (ETH Zürich); Müller, Christoph R. (ETH Zürich); Fedorov, Alexey (ETH Zürich)","","2023","The direct synthesis of methanol via the hydrogenation of CO2, if performed efficiently and selectively, is potentially a powerful technology for CO2 mitigation. Here, we develop an active and selective Cu-Zn/SiO2 catalyst for the hydrogenation of CO2 by introducing copper and zinc onto dehydroxylated silica via surface organometallic chemistry and atomic layer deposition, respectively. At 230 °C and 25 bar, the optimized catalyst shows an intrinsic methanol formation rate of 4.3 g h-1 gCu-1 and selectivity to methanol of 83%, with a space-time yield of 0.073 g h-1 gcat-1 at a contact time of 0.06 s g mL-1. X-ray absorption spectroscopy at the Cu and Zn K-edges and X-ray photoelectron spectroscopy studies reveal that the CuZn alloy displays reactive metal support interactions; that is, it is stable under H2 atmosphere and unstable under conditions of CO2 hydrogenation, indicating that the dealloyed structure contains the sites promoting methanol synthesis. While solid-state nuclear magnetic resonance studies identify methoxy species as the main stable surface adsorbate, transient operando diffuse reflectance infrared Fourier transform spectroscopy indicates that μ-HCOO*(ZnOx) species that form on the Cu-Zn/SiO2 catalyst are hydrogenated to methanol faster than the μ-HCOO*(Cu) species that are found in the Zn-free Cu/SiO2 catalyst, supporting the role of Zn in providing a higher activity in the Cu-Zn system.","ALD; CO hydrogenation; CuZn alloy; dealloying; operando DRIFTS; SOMC","en","journal article","","","","","","","","","","","ChemE/Catalysis Engineering","","",""
"uuid:a5beb13b-56f8-426c-acd4-e6a29e50d20e","http://resolver.tudelft.nl/uuid:a5beb13b-56f8-426c-acd4-e6a29e50d20e","Wastewater-based epidemiology predicts COVID-19-induced weekly new hospital admissions in over 150 USA counties","Li, Xuan (University of Technology Sydney); Liu, Huan (University of Technology Sydney); Gao, Li (South East Water); Sherchan, Samendra P. (Morgan State University; Tulane University); Zhou, Ting (University of Technology Sydney); Khan, Stuart J. (University of New South Wales); van Loosdrecht, Mark C.M. (TU Delft BT/Environmental Biotechnology); Wang, Qilin (University of Technology Sydney)","","2023","Although the coronavirus disease (COVID-19) emergency status is easing, the COVID-19 pandemic continues to affect healthcare systems globally. It is crucial to have a reliable and population-wide prediction tool for estimating COVID-19-induced hospital admissions. We evaluated the feasibility of using wastewater-based epidemiology (WBE) to predict COVID-19-induced weekly new hospitalizations in 159 counties across 45 states in the United States of America (USA), covering a population of nearly 100 million. Using county-level weekly wastewater surveillance data (over 20 months), WBE-based models were established through the random forest algorithm. WBE-based models accurately predicted the county-level weekly new admissions, allowing a preparation window of 1-4 weeks. In real applications, periodically updated WBE-based models showed good accuracy and transferability, with mean absolute error within 4-6 patients/100k population for upcoming weekly new hospitalization numbers. Our study demonstrated the potential of using WBE as an effective method to provide early warnings for healthcare systems.","","en","journal article","","","","","","","","","","","BT/Environmental Biotechnology","","",""
"uuid:555d035f-deed-4d3c-912b-60a9c4c99969","http://resolver.tudelft.nl/uuid:555d035f-deed-4d3c-912b-60a9c4c99969","Physiomimetic biocompatibility evaluation of directly printed degradable porous iron implants using various cell types","Li, Y. (TU Delft Biomaterials & Tissue Biomechanics; University of Science and Technology Beijing); Pavanram, P. (University Hospital RWTH Aachen); Bühring, J. (Rheinisch-Westfälische Technische Hochschule); Rütten, S. (University Hospital RWTH Aachen); Schröder, K. U. (Rheinisch-Westfälische Technische Hochschule); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Pufe, T. (University Hospital RWTH Aachen); Wang, L. . (University of Science and Technology Beijing); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics); Jahr, H. (Rheinisch-Westfälische Technische Hochschule; University Hospital RWTH Aachen)","","2023","Additively manufactured (AM) degradable porous metallic biomaterials offer unique opportunities for satisfying the design requirements of an ideal bone substitute. Among the currently available biodegradable metals, iron has the highest elastic modulus, meaning that it would benefit the most from porous design. Given the successful preclinical applications of such biomaterials for the treatment of cardiovascular diseases, the moderate compatibility of AM porous iron with osteoblast-like cells, reported in earlier studies, has been surprising. This may be because, as opposed to static in vitro conditions, the biodegradation products of iron in vivo are transported away and excreted. To better mimic the in situ situations of biodegradable biomaterials after implantation, we compared the biodegradation behavior and cytocompatibility of AM porous iron under static conditions to the conditions with dynamic in situ-like fluid flow perfusion in a bioreactor. Furthermore, the compatibility of these scaffolds with four different cell types was evaluated to better understand the implications of these implants for the complex process of natural wound healing. These included endothelial cells, L929 fibroblasts, RAW264.7 macrophage-like cells, and osteoblastic MG-63 cells. The biodegradation rate of the scaffolds was significantly increased in the perfusion bioreactor as compared to static immersion. Under either condition, the compatibility with L929 cells was the best. Moreover, the compatibility with all the cell types was much enhanced under physiomimetic dynamic flow conditions as compared to static biodegradation. Our study highlights the importance of physiomimetic culture conditions and cell type selection when evaluating the cytocompatibility of degradable biomaterials in vitro. Statement of Significance: Additively manufactured (AM) degradable porous metals offer unique opportunities for the treatment of large bony defects. Despite the successful preclinical applications of biodegradable iron in the cardiovascular field, the moderate compatibility of AM porous iron with osteoblast-like cells was reported. To better mimic the in vivo condition, we compared the biodegradation behavior and cytocompatibility of AM porous iron under static condition to dynamic perfusion. Furthermore, the compatibility of these scaffolds with various cell types was evaluated to better simulate the process of natural wound healing. Our study suggests that AM porous iron holds great promise for orthopedic applications, while also highlighting the importance of physio-mimetic culture conditions and cell type selection when evaluating the cytocompatibility of degradable biomaterials in vitro.","Additive manufacturing; Biocompatibility; Biodegradation; MG-63, L929, HUVEC, RAW264.7; Perfusion bioreactor; Porous iron","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-02-01","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:50edb126-c29a-4fe7-9f71-1464f97d40a3","http://resolver.tudelft.nl/uuid:50edb126-c29a-4fe7-9f71-1464f97d40a3","Promotion effects of alkali metals on iron molybdate catalysts for CO2 catalytic hydrogenation","Zhou, Yong (Université de Lille; University of Artois); Sadia Traore, Aliou (University of Strasbourg); Peron, Deizi V. (Université de Lille; University of Artois); Barrios, Alan J. (Université de Lille; University of Artois); Chernyak, Sergei A. (Université de Lille; University of Artois); Corda, Massimo (Université de Lille); Safonova, Olga V. (Paul Scherrer Institut); Dugulan, A.I. (TU Delft RST/Fundamental Aspects of Materials and Energy; TU Delft RID/TS/Instrumenten groep); Ersen, Ovidiu (University of Strasbourg)","","2023","CO2 hydrogenation is an attractive way to store and utilize carbon dioxide generated by industrial processes, as well as to produce valuable chemicals from renewable and abundant resources. Iron catalysts are commonly used for the hydrogenation of carbon oxides to hydrocarbons. Iron-molybdenum catalysts have found numerous applications in catalysis, but have been never evaluated in the CO2 hydrogenation. In this work, the structural properties of iron-molybdenum catalysts without and with a promoting alkali metal (Li, Na, K, Rb, or Cs) were characterized using X-ray diffraction, hydrogen temperature-programmed reduction, CO2 temperature-programmed desorption, in-situ 57Fe Mossbauer spectroscopy and operando X-ray adsorption spectroscopy. Their catalytic performance was evaluated in the CO2 hydrogenation. During the reaction conditions, the catalysts undergo the formation of an iron (II) molybdate structure, accompanied by a partial reduction of molybdenum and carbidization of iron. The rate of CO2 conversion and product selectivity strongly depend on the promoting alkali metals, and electronegativity was identified as an important factor affecting the catalytic performance. Higher CO2 conversion rates were observed with the promoters having higher electronegativity, while low electronegativity of alkali metals favors higher light olefin selectivity.","Alkali metals; CO utilization; In-situ characterization; Iron molybdate catalysts; Light olefins; Promotion","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-01-01","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:5bff66fb-4568-4659-b0e2-a7181dbf7ef6","http://resolver.tudelft.nl/uuid:5bff66fb-4568-4659-b0e2-a7181dbf7ef6","Biomechanical evaluation of additively manufactured patient-specific mandibular cage implants designed with a semi-automated workflow: A cadaveric and retrospective case study","van Kootwijk, A. (Erasmus MC); Jonker, B. P. (Erasmus MC); Wolvius, E. B. (Erasmus MC); Cruz Saldivar, M. (TU Delft Biomaterials & Tissue Biomechanics); Leeflang, M.A. (TU Delft Biomaterials & Tissue Biomechanics); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Tümer, N. (TU Delft Biomaterials & Tissue Biomechanics); Mirzaali, Mohammad J. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2023","Objective: Mandibular reconstruction using patient-specific cage implants is a promising alternative to the vascularized free flap reconstruction for nonirradiated patients with adequate soft tissues, or for patients whose clinical condition is not conducive to microsurgical reconstruction. This study aimed to assess the biomechanical performance of 3D printed patient-specific cage implants designed with a semi-automated workflow in a combined cadaveric and retrospective case series study. Methods: We designed cage implants for two human cadaveric mandibles using our previously developed design workflow. The biomechanical performance of the implants was assessed with the finite element analysis (FEA) and quasi-static biomechanical testing. Digital image correlation (DIC) was used to measure the full-field strains and validate the FE models by comparing the distribution of maximum principal strains within the bone. The retrospective study of a case series involved three patients, each of whom was treated with a cage implant of similar design. The biomechanical performance of these implants was evaluated using the experimentally validated FEA under the scenarios of both mandibular union and nonunion. Results: No implant or screw failure was observed prior to contralateral bone fracture during the quasi-static testing of both cadaveric mandibles. The FEA and DIC strain contour plots indicated a strong linear correlation (r = 0.92) and a low standard error (SE=29.32με), with computational models yielding higher strain values by a factor of 2.7. The overall stresses acting on the case series’ implants stayed well below the yield strength of additively manufactured (AM) commercially pure titanium, when simulated under highly strenuous chewing conditions. Simulating a full union between the graft and remnant mandible yielded a substantial reduction (72.7±1.5%) in local peak stresses within the implants as compared to a non-bonded graft. Conclusions: This study shows the suitability of the developed semi-automated workflow in designing patient-specific cage implants with satisfactory mechanical functioning under demanding chewing conditions. The proposed workflow can aid clinical engineers in creating reconstruction systems and streamlining pre-surgical planning. Nevertheless, more research is still needed to evaluate the osteogenic potential of bone graft insertions.","3D printing; Automated implant design; Biomechanical study; Finite element method; Mandibular reconstruction; Patient-specific implant","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:e70a7df9-9492-4785-8283-33534a622a0d","http://resolver.tudelft.nl/uuid:e70a7df9-9492-4785-8283-33534a622a0d","A critical review on the vertical stiffness irregularity of railway ballasted track","Shi, Can (Shenzhen University); Zhou, Yu (Shenzhen University); Xu, Lei (Central South University China); Zhang, Xu (Guangdong University of Technology); Guo, Y. (TU Delft Railway Engineering)","","2023","The dynamic performance of a railway track subjected to moving trains depends strongly on track support conditions. In reality, even for the well-constructed and well-maintained tracks, sleeper support stiffness and global track stiffness vary substantially along the track, which affects the train-track dynamic interactions, causing rapid track geometry degradation as well as the riding comfort and safety issues. Consequently, track stiffness irregularity (TSI, the spatial variation of track stiffness along the track) is important for railway construction and maintenance in addition to track geometry irregularities. So far, extensive research has been published on the TSI whereas the relevant issues have not been paid sufficient attention. In this paper, a summary and comments have been made in the field of TSI about the current research status and future trends from a critical point of view. Novel concepts of the critical values of TSIs and the integrated management of the track geometry and stiffness irregularities are proposed. The review presented in this work is valuable to advance the research on TSI and can help guide the design, construction and maintenance of railway tracks.","Measurement results; Optimal track stiffness; Track stiffness irregularity; Train-track performance","en","review","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-02-05","","","Railway Engineering","","",""
"uuid:288d1928-4fba-4db7-b292-c5feacdc08a9","http://resolver.tudelft.nl/uuid:288d1928-4fba-4db7-b292-c5feacdc08a9","Advanced controls on energy reliability, flexibility and occupant-centric control for smart and energy-efficient buildings","Liu, Zhengxuan (TU Delft Design & Construction Management); Zhang, Xiang (University of Pennsylvania); Sun, Ying (Qingdao University of Technology); Zhou, Yuekuan (The Hong Kong University of Science and Technology)","","2023","Advanced controls have attracted increasing interests due to the high requirement on smart and energy-efficient (SEE) buildings and decarbonization in the building industry with optimal tradeoff strategies between energy consumption and thermal comfort of built environment. However, a state-of-the-art review is lacking on advanced controls for SEE buildings, especially considering advanced building energy systems, machine learning based advanced controls, and advanced occupant-centric controls (OCC). This study presents a comprehensive review on the latest advancement of advanced controls for SEE buildings, which covers recent research on data collection through smart metering and sensors, big data and building automation, energy digitization, and building energy simulation. Machine learning based advanced controls are comprehensively reviewed, including supervised, unsupervised and reinforcement learning, together with their roles and underlying mechanisms. In addition, advanced controls for energy security, reliability, robustness, flexibility, and resilience are further reviewed for energy-efficient and low-carbon buildings, with respect to fault detection and diagnosis, fire alarming and building energy safety, and climate change adaptation. Moreover, this study explores the advanced OCC systems and their applications in SEE buildings. Last but not the least, this study emphasizes the challenges and future prospects of the trade-off between complexity and predictive/control performance, AI-based controllers and climate change adaptation, OCC in thermal comfort and energy saving for the SEE buildings. This study offers valuable insights into the latest research progress concerning the underlying mechanisms, algorithms and applications of advanced controls for SEE buildings, paving the path for sustainable and low-carbon transition in building sectors.","Energy-efficient building; Intelligent control; Machine learning; Occupant-centric control; Smart building","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-02-09","","","Design & Construction Management","","",""
"uuid:75bf088b-87eb-4cd5-a78b-c0063d589b93","http://resolver.tudelft.nl/uuid:75bf088b-87eb-4cd5-a78b-c0063d589b93","The evolution of ontology in AEC: A two-decade synthesis, application domains, and future directions","Farghaly, Karim (University College London (UCL)); Soman, R. K. (TU Delft Integral Design & Management); Zhou, Shanjing Alexander (University College London (UCL); The Hong Kong University of Science and Technology)","","2023","Ontologies play a pivotal role in knowledge representation, particularly beneficial for the Architecture, Engineering, and Construction (AEC) sector due to its inherent data diversity and intricacy. Despite the growing interest in ontology and data integration research, especially with the advent of knowledge graphs and digital twins, a noticeable lack of consolidated academic synthesis still needs to be addressed. This review paper aims to bridge that gap, meticulously analysing 142 journal articles from 2000 to 2021 on the application of ontologies in the AEC sector. The research is segmented through systematic evaluation into ten application domains within the construction realm- process, cost, operation/maintenance, health/safety, sustainability, monitoring/control, intelligent cities, heritage building information modelling (HBIM), compliance, and miscellaneous. This categorisation aids in pinpointing ontologies suitable for various research objectives. Furthermore, the paper highlights prevalent limitations within current ontology studies in the AEC sector. It offers strategic recommendations, presenting a well-defined path for future research to address these gaps.","Building information modelling; Industry foundation classes (IFC); Interoperability; Linked data; Ontology; Semantic web","en","review","","","","","","","","","","","Integral Design & Management","","",""
"uuid:08bf0e3e-cca9-4175-b4b4-c20db9a9fe7b","http://resolver.tudelft.nl/uuid:08bf0e3e-cca9-4175-b4b4-c20db9a9fe7b","Frontier ocean thermal/power and solar PV systems for transformation towards net-zero communities","Liu, Zhengxuan (TU Delft Design & Construction Management); Zhou, Yuekuan (The Hong Kong University of Science and Technology); Yan, Jun (Shanghai Jiao Tong University); Tostado-Véliz, Marcos (Universidad de Jaén)","","2023","Ocean thermal and power energy systems are promising driving forces for seashore coastal communities to achieve net-zero energy/emission target, whereas energy planning and management on ocean thermal/power and distributed building integrated photovoltaic (BIPV) systems are critical, in terms of serving scale sizing and planning on geographical locations of district building community, and cycling aging of battery storages. However, the current literature provides insufficient studies on this topic. This study aims to address this research gap by transforming towards zero-energy coastal communities from the district level in subtropical regions, including centralised seawater-based chiller systems, distributed BIPVs and coastal oscillating water column technologies, as well as multi-directional Vehicle-to-Building energy interaction paradigms. Advanced energy management strategies were explored to enhance renewable penetration, import cost-saving, and deceleration of battery cycling aging, in response to relative renewable-to-demand difference, off-peak grid information with low price, and real-time battery cycling aging. Furthermore, in accordance with the power generation characteristic of two wave stations (i.e., Kau Yi Chau (KYC) and West Lamma Channel (WLC)) in Hong Kong, energy system planning and structural configurations of the coastal community were proposed and comparatively studied for the multi-criteria performance improvement. Research results showed that, compared to an air-cooled chiller, the water-cooled chiller with a much higher Coefficient of Performance (COP) will reduce the energy consumption of cooling systems, leading to a decrease in total electric demand from 134 to 126.5 kWh/m2·a. The scale for the net-zero energy district community with distributed BIPVs and oscillating water column was identified as 5 high-rise office buildings, 5 high-rise hotel buildings, 150 private cars and 120 public shuttle buses. Furthermore, the geographical location planning scheme on the Case 1 (office buildings close to KYC, and hotel buildings close to WLC) was identified as the most economically and environmentally feasible scheme, whereas the Case 3 (only office buildings are planned close to all power supply with oscillating water column) showed the highest flexibility in grid electricity shifting, together with the highest value of equivalent battery relative capacity. This study demonstrates techno-economic performances and energy flexibility of frontier ocean energy technologies in a coastal community under advanced energy management strategies, together with technical guidance for serving scale sizing and planning on geographical locations. The research results highlight the prospects and promote frontier ocean energy techniques in subtropical coastal regions.","Coastal oscillating water column; Cycling aging of battery; Energy management strategy; Ocean thermal/power energy; Scale sizing and energy planning; Solar energy","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care. Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-01-13","","","Design & Construction Management","","",""
"uuid:39838976-4df2-4d10-8ea8-f8df88558a63","http://resolver.tudelft.nl/uuid:39838976-4df2-4d10-8ea8-f8df88558a63","Critical considerations and effective assessment of extraction and recovery processes of RAP","Zhong, Haobai (Tongji University); Huang, Weidong (Tongji University); Lin, P. (TU Delft Pavement Engineering); Zhou, L. (University of Nottingham); Lv, Quan (Tongji University)","","2023","With the increasing shortage of resources, the reuse of recycled asphalt pavements (RAP) in pavement engineering is considered as a sustainable technology. Challenges posed by common extraction and recovery methods may result in misjudgment of asphalt pavement performance. In this study, we investigate the optimization of extraction and recovery processes in recycled asphalt pavement (RAP) recycling, aiming to promote sustainable development within the pavement engineering sector. We prepared eleven asphalt samples to simulate common extraction and recovery scenarios, using virgin SBS-modified asphalt as a reference. Employing Fourier Transform Infrared (FTIR) analysis, thermogravimetric analysis (TGA), and Dynamic Shear Rheometer (DSR) testing, we assessed the samples' rheological and chemical properties. We pointed out three common but easily overlooked problems in the extraction and recovery process, namely residual mineral powder, residual trichloroethylene, and incomplete extraction. Residual mineral powder and trichloroethylene greatly influence extraction recovery accuracy; high-speed centrifugation effectively addresses trichloroethylene, but completely removing mineral powder remains challenging. Accurate evaluation of residual substances in recycled asphalt is achievable through FTIR, TGA, and rheological tests, providing valuable insights for material selection and processing. Additionally, it is crucial to fully recover the binder from RAP for precise performance evaluation, as the binder's interior exhibits lower aging levels compared to the surface. This aging heterogeneity should be considered when assessing RAP performance and developing effective rehabilitation strategies. Our findings hold significant implications for enhancing the efficiency and effectiveness of extraction and recovery processes in RAP recycling, ultimately contributing to sustainable development in pavement engineering.","Aging heterogeneity; Extraction optimization; RAP recycling; Residual substances; Sustainability","en","journal article","","","","","","","","","","","Pavement Engineering","","",""
"uuid:3e98f1e9-10ab-4573-857b-8e72d285a37a","http://resolver.tudelft.nl/uuid:3e98f1e9-10ab-4573-857b-8e72d285a37a","Release behavior of soluble salts in MSWI bottom ash used as road basement materials under continuous rainfall conditions","Zhao, Lingqin (Zhejiang University); Zhang, Dongming (Zhejiang Zheneng Xingyuan Energy Saving Technology Co. Ltd); Hu, Yanjun (Zhejiang University); Guo, Qianqian (Zhejiang University); Jiao, Long (Zhejiang University); Zhou, Nan (Zhejiang University); Di Maio, F. (TU Delft Resources & Recycling)","","2023","The bottom ash is increasingly used as a substitute aggregate material in road construction in China, and road salting is the major salt source in groundwater. Continuous rainfall releases soluble salts from the bottom ash subgrade into the surrounding soil and groundwater, resulting in potential hazards. Different methods were employed to simulate and collect runoff water during rainfall events, including batch leaching test, dynamic leaching test and constant head test, to assess environmental impact of bottom ash as road basement materials under continuous rainfall conditions. This study simulated the seepage of bottom ash backfill roads under different rainfall intensities, rainfall times, and rainfall pH values. A comprehensive sampling and laboratory testing program was undertaken to characterize the environmental impact of soluble salts from bottom ash. The obtained results reveal that the leaching concentrations of Cl− and SO42− exceed the limit specified in the class V standard of surface water, which are 2.06–2.17 times and 1.08–1.25 times, respectively. By examining the long-term environmental influence under the condition of continuous rainfall, the leaching of Cl− mainly occurs in the early leaching stage, and the maximum leaching concentration reaches 19,700 mg/L. The release concentration of Cl− begins to be lower than the class V standard of surface water when continuous rainfall approaches the total rainfall for 13 months. The cumulative release of Cl− in the bottom ash is 2.8–5.4 mg/g. Both rainfall intensity and rain pH affect the release of Cl−. The obtained results derived from the constant head tests indicate that stagnant water caused by rainfall deteriorates the release of soluble salt into the groundwater in only 1 day, especially at the early stage of 12 h. This work provides some basic information about how to minimize damage to the surrounding environment caused by the leaching of salt in bottom ash.","Continuous rainfall; Incineration bottom ash; Leaching; Municipal solid waste; Salts","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-03-02","","","Resources & Recycling","","",""
"uuid:32b815c2-b775-41a7-9c2b-4afec67b3ab2","http://resolver.tudelft.nl/uuid:32b815c2-b775-41a7-9c2b-4afec67b3ab2","Progress toward the sustainable development of world cultural heritage sites facing land-cover changes","Guo, Huadong (International Research Center for Big Data for Sustainable Development Goals; International Centre on Space Technologies for Natural and Cultural Heritage under the Auspices of UNESCO); Chen, Fulong (International Research Center for Big Data for Sustainable Development Goals; Chinese Academy of Sciences; International Centre on Space Technologies for Natural and Cultural Heritage under the Auspices of UNESCO); Tang, Yunwei (International Research Center for Big Data for Sustainable Development Goals; Chinese Academy of Sciences); Ding, Yanbin (Hengyang Normal University); Chen, Min (Nanjing Normal University); Zhou, Wei (International Research Center for Big Data for Sustainable Development Goals; Chinese Academy of Sciences; International Centre on Space Technologies for Natural and Cultural Heritage under the Auspices of UNESCO); Zhu, Meng (International Research Center for Big Data for Sustainable Development Goals; Chinese Academy of Sciences; International Centre on Space Technologies for Natural and Cultural Heritage under the Auspices of UNESCO); Zheng, Wenwu (Hengyang Normal University); Pereira Roders, A. (TU Delft Heritage & Architecture)","","2023","The quantification of the extent and dynamics of land-use changes is a key metric employed to assess the progress toward several Sustainable Development Goals (SDGs) that form part of the United Nations 2030 Sustainable Development Agenda. In terms of anthropogenic factors threatening the conservation of heritage properties, such a metric aids in the assessment of achievements toward heritage sustainability solving the problem of insufficient data availability. Therefore, in this study, 589 cultural World Heritage List (WHL) properties from 115 countries were analyzed, encompassing globally distributed and statistically significant samples of “monuments and groups of buildings” (73.2%), “sites” (19.3%), and “cultural landscapes” (7.5%). Land-cover changes in the WHL properties between 2015 and 2020 were automatically extracted from big data collections of high-resolution satellite imagery accessed via Google Earth Engine using intelligent remote sensing classification. Sustainability indexes (SIs) were estimated for the protection zones of each property, and the results were employed, for the first time, to assess the progress of each country toward SDG Target 11.4. Despite the apparent advances in SIs (10.4%), most countries either exhibited steady (20.0%) or declining (69.6%) SIs due to limited cultural investigations and enhanced negative anthropogenic disturbances. This study confirms that land-cover changes are among serious threats for heritage conservation, with heritage in some countries wherein the need to address this threat is most crucial, and the proposed spatiotemporal monitoring approach is recommended.","","en","journal article","","","","","","","","","","","Heritage & Architecture","","",""
"uuid:9e066479-d288-4a8a-b962-5a312e56f337","http://resolver.tudelft.nl/uuid:9e066479-d288-4a8a-b962-5a312e56f337","Experimental investigation of wave attenuation by mangrove forests with submerged canopies","Zhang, R. (Hohai University; State Environmental Protection Key Laboratory of Marine Ecosystem Restoration); Chen, Y. (Hohai University); Lei, Jiaxin (Hohai University); Zhou, Xin (Hohai University; Ministry of Land and Resources of China); Yao, P. (Hohai University); Stive, M.J.F. (TU Delft Coastal Engineering)","","2023","Mangroves can function as a ‘bio-shield’ to protect coastal communities from harsh environments because of their strong ability to attenuate wave energy. However, as mangroves are usually oversimplified as rigid cylinders in antecedent studies, the effects of complex mangrove morphology on wave attenuation have not been well researched. Although increasing attention has been paid to the wave dissipation induced by varying mangrove morphologies, most of them focus on the bottom trunk and root components of mature mangrove trees. There are few investigations about the contributions of the canopies of young saplings and/or short species to wave attenuation. To bridge this knowledge gap, a series of laboratory experiments under regular waves were conducted to examine the hydrodynamic variations affected by varying mangrove morphology configurations. Three water depths were considered to explore the influences of the vertical-varying submerged volume of mangroves when the artificial mangrove models are submerged, nearly emergent, and fully emergent. The mangrove forest model is 2 m long at a 1:10 scale. Three mangrove configurations, i.e. with no canopy, sparse canopy, and dense canopy were applied and compared to isolate the wave attenuation contributed by mangrove canopies. The results highlight the wave energy attenuation attributed to the canopy density. A linear correlation is found between the wave damping factor and a new variable named hydraulic submerged volume index (HSVI). The bulk drag coefficient, including canopy effects, was calculated to characterize mangrove-induced wave attenuation when the mangrove canopy is submerged. The relationships between the bulk drag coefficient CD and the characteristic hydraulic numbers (i.e., Reynolds number, Keulegan–Carpenter number, Ursell number) are discussed in detail. Consequently, new generic formulas of CD were deduced considering the effects of the submerged canopy. The employment of new CD formulas improves the reliability of the prediction of the wave attenuation ability by mangroves since the canopy effects are incorporated.","Drag coefficient; Experimental analysis; Submerged mangrove canopies; Wave attenuation; Wave damping factor","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-03-23","","","Coastal Engineering","","",""
"uuid:e8abab9a-e708-40c0-8fb5-79df072b3e1a","http://resolver.tudelft.nl/uuid:e8abab9a-e708-40c0-8fb5-79df072b3e1a","TTMRN: A topological-geometric two-layer maritime route network modeling for ship intelligent navigation","Zhou, Chunhui (Wuhan University of Technology; China Laboratory of Transport Pollution Control and Monitoring Technology; Hubei Key Laboratory of Inland Shipping Technology); Xiang, Jiale (Wuhan University of Technology; Hubei Key Laboratory of Inland Shipping Technology); Huang, Hongxun (Wuhan University of Technology; Hubei Key Laboratory of Inland Shipping Technology); Yan, Yi (Wuhan University of Technology; Hubei Key Laboratory of Inland Shipping Technology); Huang, L. (TU Delft Safety and Security Science; Wuhan University of Technology); Wen, Yuanqiao (National Engineering Research Center for Water Transport Safety; Wuhan University of Technology); Xiao, Changshi (Wuhan University of Technology; Hubei Key Laboratory of Inland Shipping Technology)","","2023","The construction of maritime route networks holds significant importance for autonomous navigation of vessels. In this study, a two-layer maritime route network modeling method based on huge amounts of ship trajectory data was proposed. Firstly, we introduce a novel method for extracting nodes of the marine route network, which identifies feature points in ship trajectories through clustering. Secondly, we use a spatial computing method to transform ship trajectory data into a sequence of waypoint regions and establish a node connection matrix to realize the nodes' connection of the topological layer route network. And routes are extracted between waypoint regions to characterize the connection relationship of the geometric layer network. Finally, by connecting nodes of the topological layer with the support of the connection matrix and waypoint regions of the geometric layer with the route, the two-layer maritime route network that combines topological and geometric layers is constructed. The proposed method was applied to the waters of Vancouver, successfully constructing a topological-geometric two-layer maritime route network. Overall, the proposed method is beneficial for improving the safety and efficiency of autonomous navigation of ships, and has a positive impact on the development of smart shipping industry.","AIS data; Cluster analysis; Intelligent navigation; Maritime route network; Trajectory feature points","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-03-23","","","Safety and Security Science","","",""
"uuid:617375c2-27ed-429d-bb8c-a0ffef28e042","http://resolver.tudelft.nl/uuid:617375c2-27ed-429d-bb8c-a0ffef28e042","Extrusion-based 3D printing of biodegradable, osteogenic, paramagnetic, and porous FeMn-akermanite bone substitutes","Putra, N.E. (TU Delft Biomaterials & Tissue Biomechanics); Leeflang, M.A. (TU Delft Biomaterials & Tissue Biomechanics); Klimopoulou, M. (TU Delft Biomaterials & Tissue Biomechanics); Dong, J. (TU Delft Biomaterials & Tissue Biomechanics); Taheri, P. (TU Delft Team Peyman Taheri); Huan, Z. (Shanghai Institute of Ceramics Chinese Academy of Sciences); Fratila-Apachitei, E.L. (TU Delft Biomaterials & Tissue Biomechanics); Mol, J.M.C. (TU Delft Team Arjan Mol); Chang, J. (Shanghai Institute of Ceramics Chinese Academy of Sciences); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2023","The development of biodegradable Fe-based bone implants has rapidly progressed in recent years. Most of the challenges encountered in developing such implants have been tackled individually or in combination using additive manufacturing technologies. Yet not all the challenges have been overcome. Herein, we present porous FeMn-akermanite composite scaffolds fabricated by extrusion-based 3D printing to address the unmet clinical needs associated with Fe-based biomaterials for bone regeneration, including low biodegradation rate, MRI-incompatibility, mechanical properties, and limited bioactivity. In this research, we developed inks containing Fe, 35 wt% Mn, and 20 or 30 vol% akermanite powder mixtures. 3D printing was optimized together with the debinding and sintering steps to obtain scaffolds with interconnected porosity of 69%. The Fe-matrix in the composites contained the γ-FeMn phase as well as nesosilicate phases. The former made the composites paramagnetic and, thus, MRI-friendly. The in vitro biodegradation rates of the composites with 20 and 30 vol% akermanite were respectively 0.24 and 0.27 mm/y, falling within the ideal range of biodegradation rates for bone substitution. The yield strengths of the porous composites stayed within the range of the values of the trabecular bone, despite in vitro biodegradation for 28 d. All the composite scaffolds favored the adhesion, proliferation, and osteogenic differentiation of preosteoblasts, as revealed by Runx2 assay. Moreover, osteopontin was detected in the extracellular matrix of cells on the scaffolds. Altogether, these results demonstrate the remarkable potential of these composites in fulfilling the requirements of porous biodegradable bone substitutes, motivating future in vivo research. Statement of significance: We developed FeMn-akermanite composite scaffolds by taking advantage of the multi-material capacity of extrusion-based 3D printing. Our results demonstrated that the FeMn-akermanite scaffolds showed an exceptional performance in fulfilling all the requirements for bone substitution in vitro, i.e., a sufficient biodegradation rate, having mechanical properties in the range of trabecular bone even after 4 weeks biodegradation, paramagnetic, cytocompatible and most importantly osteogenic. Our results encourage further research on Fe-based bone implants in in vivo.","Akermanite; Biodegradable; Bone; Extrusion-based 3D printing; Iron-manganese; Scaffold","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:cb6b6300-7699-46b2-968f-b8ae83cc4875","http://resolver.tudelft.nl/uuid:cb6b6300-7699-46b2-968f-b8ae83cc4875","Deep Learning in Maritime Autonomous Surface Ships: Current Development and Challenges","Ye, Jun (Wuhan University of Technology); Li, Chengxi (The Hong Kong Polytechnic University); Wen, Weisong (The Hong Kong Polytechnic University); Zhou, Ruiping (Wuhan University of Technology); Reppa, V. (TU Delft Transport Engineering and Logistics)","","2023","Autonomous surface ships have become increasingly interesting for commercial maritime sectors. Before deep learning (DL) was proposed, surface ship autonomy was mostly model-based. The development of artificial intelligence (AI) has prompted new challenges in the maritime industry. A detailed literature study and examination of DL applications in autonomous surface ships are still missing. Thus, this article reviews the current progress and applications of DL in the field of ship autonomy. The history of different DL methods and their application in autonomous surface ships is briefly outlined. Then, the previously published works studying DL methods in ship autonomy have been categorized into four groups, i.e., control systems, ship navigation, monitoring system, and transportation and logistics. The state-of-the-art of this review paper majorly lies in presenting the existing limitations and innovations of different applications. Subsequently, the current issues and challenges for DL application in autonomous surface ships are discussed. In addition, we have proposed a comparative study of traditional and DL algorithms in ship autonomy and also provided the future research scope as well.","Artificial intelligence (AI); Deep learning (DL); Maritime autonomous surface ships; Review","en","review","","","","","","","","2024-03-25","","","Transport Engineering and Logistics","","",""
"uuid:5b9709a2-4a02-4793-b6a3-64fe6c762daf","http://resolver.tudelft.nl/uuid:5b9709a2-4a02-4793-b6a3-64fe6c762daf","A bio-inspired and switchable H+/OH− ion-channel for room temperature exhaled CO2 chemiresistive sensing","Chen, Honghao (South China Normal University); Lu, Ruofei (South China Normal University); Gao, Yixun (South China Normal University); Yue, Xiaorui (South China Normal University); Yang, Haihong (The First Affiliated Hospital of Guangzhou Medical University); Li, Hao (South China Normal University); Lee, Yi Kuen (The Hong Kong University of Science and Technology); French, P.J. (TU Delft Bio-Electronics); Wang, Yao (South China Normal University); Zhou, Guofu (South China Normal University)","","2023","Inspired by the CO2-induced reversible activation mechanism of the slow anion channel 1 (SLAC1) in plant stomatal guard cells during plant photosynthesis, we designed and prepared a CO2- switchable H+/OH− ion channel (CSPH ion channel). A high-performance chemiresistive room temperature CO2 sensor has been prepared based on this CSPH ion channel. The obtained CO2 room temperature sensor γ-CD-MOF@RhB exhibits high sensitivity (Rg/R0 = 1.50, 100 ppm), excellent selectivity, good stability (less than 5% reduction in 30 days response value), and 99.96% consistency with commercial infrared CO2 meter. The practical limit of detection (pLOD) of the γ-CD-MOF@RhB sensor reaches 10 ppm at room temperature toward CO2, which is the lowest for reported MOF-derived chemiresistive room temperature CO2 sensors so far. Ion conduction mechanism studies have shown that the CSPH ion channel behaves as a CO2-switchable H+/OH− ion channel with a switching point of approximately 60 000 ppm CO2. As an application attempt, the fabricated low pLOD CO2 sensor has been used for human exhaled CO2 detection to compare CO2 concentration in the breath of individuals before and after exercise and COVID-19. It was also logically indicated that the average concentration of human exhaled CO2 after COVID-19 recovery is different for undiseased subjects.","","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2024-03-25","","","Bio-Electronics","","",""
"uuid:975efd29-b2af-49f1-b6d7-97df55ba5a3d","http://resolver.tudelft.nl/uuid:975efd29-b2af-49f1-b6d7-97df55ba5a3d","Quality of AM implants in biomedical application","Mirzaali, Mohammad J. (TU Delft Biomaterials & Tissue Biomechanics); Shahriari, N.S. (TU Delft Biomaterials & Tissue Biomechanics); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","Kadkhodapour, Javad (editor); Schmauder, Siegfried (editor); Sajadi, Felix (editor)","2023","Additive manufacturing (AM) technologies, particularly those based on powder bed fusion (PBF), most notably, selective laser melting (SLM) for metals, have in recent years emerged as unique fabrication methods for patient-specific implants made of metals and their alloys. The ability to manufacture complex geometries together with the other features of PBF has resulted in successful fabrication of previously unseen functional implants with reliable, reproducible, and predictable properties. The capability of SLM to manufacture a wide range of metals has made this process the most favored one in the manufacturing of implants, mostly for orthopedic applications. As such, it has received tremendous attention from both academia and industry to speed up the achievement of technological maturity, which is demonstrated by the ability to ensure the desired quality of SLM implants and reproducibility in a cost-effective manner. We will, in this chapter, address some of the critical aspects of PBF, particularly those of SLM, including the effects of geometrical design, process parameters, and material type on the quality and properties of AM implants. Finally, we will conclude this chapter with a discussion on the limitations, challenges, and outlook of SLM for implants.","Additive manufacturing; Metallic implants; Orthopedic implants; Porous implants; Selective laser melting; Surface quality of AM implants","en","book chapter","Elsevier","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-27","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:0119ce73-6c43-44bf-ac51-6769ed0cd767","http://resolver.tudelft.nl/uuid:0119ce73-6c43-44bf-ac51-6769ed0cd767","Damage Mode Identification of CFRP-Strengthened Beam Based on Acoustic Emission Technique","Pan, Tanbo (Tongji University); Zheng, Yonglai (Tongji University); Zhou, Y. (TU Delft Concrete Structures); Wu, Zhuorui (Tongji University); Zhou, Yujue (Tongji University)","Ilki, Alper (editor); Çavunt, Derya (editor); Çavunt, Yavuz Selim (editor)","2023","Externally bonded (EB) carbon fiber reinforced polymer (CFRP) is widely used in structural strengthening and retrofitting. Premature debonding of the FRP severely limits the efficiency of CFRP utilization. The application of CRRP anchorage system offers a solution to the debonding problem. However, the understanding of damage mode identification of this combined system still remains elusive. Acoustic emission (AE) technique is employed to identify the damage mode of this CFRP anchorage system, due to its high sensitivity and the ability to detect damage in real-time. The objective of the current study is to identify the failure mechanisms of CFRP-strengthened beam by applying advanced pattern recognition techniques to the collected AE data. Firstly, four-point test of CFRP-strengthened beam was carried out until failure with simultaneous recording of AE signals. Then, correlation analysis was adopted to select the AE characteristic parameters, and principal component analysis (PCA) was used for dimensionality reduction. Lastly, the AE signals of the CFRP-strengthened beam was clustered to track the evolutionary behavior of the different damage modes by Gaussian mixture model (GMM) algorithm. Three main damage modes of CFRP-strengthened beam were identified by GMM clustering: concrete cracking, debonding of CFRP sheet and fracture of CFRP sheet. This study explores the damage evolution mechanism of combined system and provides a basis for achieving health monitoring of CFRP-strengthened structures.","Acoustic emission; CFRP anchorage system; Damage mode identification; Gaussian mixed model clustering; Principal component analysis","en","conference paper","Springer","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-12-03","","","Concrete Structures","","",""
"uuid:1662ab09-95dc-4289-8faf-13a6bb22ef3b","http://resolver.tudelft.nl/uuid:1662ab09-95dc-4289-8faf-13a6bb22ef3b","Cyano-Chromic Interface: Aligning Human-Microbe Temporalities Towards Noticing and Attending to Living Artefacts","Zhou, J. (TU Delft Mechatronic Design); Kim, Raphael (TU Delft Materials and Manufacturing); Doubrovski, E.L. (TU Delft Mechatronic Design); Soares de Oliveira Martins, J. (TU Delft Mechatronic Design); Giaccardi, Elisa (TU Delft Human Information Communication Design); Karana, E. (TU Delft Emerging Materials; Avans University of Applied Sciences)","Byrne, D. (editor); Martelaro, N. (editor)","2023","Microbes offer designers opportunities to endow artefacts with environmental sensing and adapting abilities, and unique expressions. However, microbe-embedded artefacts present a challenge of temporal dissonance, reflected by a “time lag” typically experienced by humans in noticing the gradual and minute shifts in microbial metabolism. This could compromise fluency of interactions and may hinder timely noticing and attending to microbes in living artefacts. In addressing this challenge, we introduce Cyano-chromic Interface, in which photosynthetic activity of cyanobacteria (Synechocystis sp. PCC6803) is timely surfaced by an electrochromic (EC) material through its monochromatic display. Grounded through interface performance characterization and design primitives, we developed application concepts through which we instantiate how the interface can be tuned for diverse functional and experiential outcomes in living artefacts. We further discuss the potential of aligning human-microbe temporalities for enriched interactions and reciprocal relationships with microbes, and beyond.","cyanobacteria; human-microbe interactions; temporality; living media interfaces; microbial displays; Biological-HCI; microorganisms; surfacing livingness","en","conference paper","Association for Computing Machinery (ACM)","","","","","","","","","","Mechatronic Design","","",""
"uuid:dab6c5bb-5daa-496a-a912-8c3dfaff0ebe","http://resolver.tudelft.nl/uuid:dab6c5bb-5daa-496a-a912-8c3dfaff0ebe","Ship Behavior in Ports and Waterways: An Empirical Perspective","Zhou, Y. (TU Delft Rivers, Ports, Waterways and Dredging Engineering)","Daamen, W. (promotor); Hoogendoorn, S.P. (promotor); Vellinga, T. (promotor); Delft University of Technology (degree granting institution)","2022","As one of the most important freight transportation modes, maritime transport has been the backbone of international trade and global economy. From the cargo flow point of view, seaports and inland shipping link the individual countries and the global waterborne transportation networks. To analyze the current ship traffic and port performance or predict future scenarios, understanding ship behavior in ports and waterways is necessary. However, the depicted sailing environment is in the current studies far simpler than the real-life ports and waterways. To this end, we formulate the following research objective:
to gain empirical knowledge of ship behavior in real-life sailing environments and to empirically investigate the influencing mechanisms of intrinsic and external factors.","","en","doctoral thesis","","978-90-5584-319-0","","","","","","","","","Rivers, Ports, Waterways and Dredging Engineering","","",""
"uuid:9f1481f0-5917-481d-8aa8-c52f846492cf","http://resolver.tudelft.nl/uuid:9f1481f0-5917-481d-8aa8-c52f846492cf","Policies, applications, barriers and future trends of building information modeling technology for building sustainability and informatization in China","Xie, Mingjing (Central South University China); Qiu, Yangzi (Central South University China); Liang, Yishuang (Central South University China); Zhou, Yuekuan (The Hong Kong University of Science and Technology; HKUST Shenzhen-Hong Kong Collaborative Innovation Research Institute); Liu, Zhengxuan (TU Delft Design & Construction Management; Central South University China; Hunan University); Zhang, Guoqiang (Hunan University)","","2022","The application of building information modeling (BIM) technology has effectively supported the high-quality development of building sustainability and informatization in China. However, few studies comprehensively analyzed the enacted policies, prevalent applications, and existing barriers of the latest application and development of BIM technology in building industry from building sustainability and informatization perspectives to provide effective consultation and guidelines for its rational scale application in China. This paper firstly made a statistical analysis on the policies and standards of BIM technology issued from 2011 to 2021 in China. Moreover, the latest application, development and existing issues of BIM technology in building sustainability and informatization were also comprehensively discussed and analyzed. The main conclusions indicated that the application status of BIM technology for building sustainability and informatization in China was large in quantity, wide in scope, but low in level. The existing issue and limitation in terms of BIM application in China was mainly due to the lack of standards and domestic-oriented tools. Finally, the future outlook and recommendations of BIM technology for building sustainability and informatization in China were also presented as avenues for upcoming research.","Building information modeling; Building informatization; Building sustainability; Engineering management; Sustainable development","en","review","","","","","","","","","","","Design & Construction Management","","",""
"uuid:f495093f-c5e1-4133-b136-76aae1ae2ac7","http://resolver.tudelft.nl/uuid:f495093f-c5e1-4133-b136-76aae1ae2ac7","Use of confidence curves to represent uncertainty in hydro-meteorological time series analysis","Zhou, C. (TU Delft Water Resources)","van de Giesen, N.C. (promotor); van Nooijen, R.R.P. (copromotor); Delft University of Technology (degree granting institution)","2022","Climate change is incompatible with the assumption of stationarity. This has lead to a sharp increase in the detection and study of nonstationarity in hydro-meteorological processes. Most hydro-meteorological processes are still analyzed by studying time series of observations. From the perspective of statistical characteristics, a stationary time series does not show significant changes. On the contrary, a nonstationarity time series often shows a slowly increasing/decreasing trend or a sudden change. A sudden change or a change point is a time point that a time series shows a great change in its statistical characteristics, for instance in themean or the standard deviation. For stationary cases, hydrologists have a large number of statistical tools to analyse these time series. These tools can not only help hydrologists to gain a deep insight into time series, but they can also analyse the corresponding uncertainty. For nonstationary cases, the detection of changes has drawn the majority of attention, however, the uncertainty associated with the detection has still been rarely studied. Therefore, this PhD research aims at bridging the gap between nonstationarity detection and the uncertainty of detection. To be more specific the main scope is rooted in analysing the uncertainty associated with detecting a change point in hydro-meteorological time series. When it comes to representing uncertainties, a traditional choice is using a confidence interval with a certain confidence level. In this research instead, the uncertainty is represented by confidence curves because they are capable of capturing more information by including all confidence intervals at all confidence levels and they visualize uncertainty in a curve. To verify the general applicability of a confidence curve in representing uncertainties, both a discrete parameter and a continuous parameter are considered in this research. The location of a change point is considered as a discrete parameter, and the dependence parameter in copula models will be considered as a continuous one. Additionally, in order to simplify the construction of a confidence curve, several new approaches have been presented in this research. Based on results and findings, confidence curves have been proven to be more informative and theoretically they can represent uncertainties of all types of parameter of interest. With a confidence curve, hydrologists can easily read the uncertainty of the detected change point and this would also provide decision-makers a better insight into the nonstationarity of a time series of a hydro-meteorological observations.","Confidence curves; Confidence sets; Uncertainty","en","doctoral thesis","","","","","","","","","","","Water Resources","","",""
"uuid:f17a4315-7fef-4a15-9f08-8b56c1e491dc","http://resolver.tudelft.nl/uuid:f17a4315-7fef-4a15-9f08-8b56c1e491dc","Blockchain technologies empowering peer-to-peer trading in multi-energy systems: From advanced technologies towards applications","Hua, Weiqi (University of Oxford); Luo, Fengji (University of Sydney); Du, Liang (Temple University); Chen, Sijie (Shanghai Jiao Tong University); Kim, Taesic (Texas A and M University); Morstyn, Thomas (University of Edinburgh); Robu, Valentin (TU Delft Algorithmics; Centrum Wiskunde & Informatica (CWI)); Zhou, Yue (Cardiff University)","","2022","","","en","contribution to periodical","","","","","","","","","","","Algorithmics","","",""
"uuid:94b0cdd5-280b-4afb-a210-f19ecf12cf66","http://resolver.tudelft.nl/uuid:94b0cdd5-280b-4afb-a210-f19ecf12cf66","Bayesian deep learning for system identification","Zhou, H. (TU Delft Robot Dynamics)","Wisse, M. (promotor); Pan, W. (copromotor); Delft University of Technology (degree granting institution)","2022","Applying deep neural networks (DNNs) for system identification (SYSID) has attracted more andmore attention in recent years. The DNNs, which have universal approximation capabilities for any measurable function, have been successfully implemented in SYSID tasks with typical network structures, e.g., feed-forward neural networks and recurrent neural networks (RNNs). However, DNNs also have limitations. First, DNNs can easily overfit the training data due to the model complexity. Second, DNNs are normally regarded as black-box models, which lack interpretability and cannot be used for white-box modelling. In this thesis, we develop sparse Bayesian deep learning (SBDL) algorithms that can address these limitations in an effectivemanner.","Deep learning; System identification; Hessian calculation; Sparse Bayesian learning; Symbolic regression; Neural architecture search; Network compression","en","doctoral thesis","","978-94-6384-329-4","","","","","","","","","Robot Dynamics","","",""
"uuid:7a57b97e-6822-4ed3-8e53-e55809d21740","http://resolver.tudelft.nl/uuid:7a57b97e-6822-4ed3-8e53-e55809d21740","Contour Moments Based Manipulation of Composite Rigid-Deformable Objects With Finite Time Model Estimation and Shape/Position Control","Qi, Jiaming (Harbin Institute of Technology); Ma, Guangfu (Harbin Institute of Technology); Zhu, J. (TU Delft Learning & Autonomous Control); Zhou, Peng (The Hong Kong Polytechnic University); Lyu, Yueyong (Harbin Institute of Technology); Zhang, Haibo (Beijing Institute of Control Engineering); Navarro-Alarcon, David (The Hong Kong Polytechnic University)","","2022","The robotic manipulation of composite rigid-deformable objects (i.e., those with mixed nonhomogeneous stiffness properties) is a challenging problem with clear practical applications that, despite the recent progress in the field, it has not been sufficiently studied in the literature. To deal with this issue, in this article, we propose a new visual servoing method that has the capability to manipulate this broad class of objects (which varies from soft to rigid) with the same adaptive strategy. To quantify the object's infinite-dimensional configuration, our new approach computes a compact feedback vector of 2-D contour moments features. A sliding mode control scheme is then designed to simultaneously ensure the finite-time convergence of both the feedback shape error and the model estimation error. The stability of the proposed framework (including the boundedness of all the signals) is rigorously proved with Lyapunov theory. Detailed simulations and experiments are presented to validate the effectiveness of the proposed approach. To the best of the author's knowledge, this is the first time that contour moments along with finite-time control have been used to solve this difficult manipulation problem.","Contour moments; deformable objects; Robot kinematics; robotics; Robots; Service robots; Shape; sliding mode control (SMC); Strain; Task analysis; Visual servoing; visual-servoing","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Learning & Autonomous Control","","",""
"uuid:196ce3b4-1074-43bc-a159-329c4e0ad514","http://resolver.tudelft.nl/uuid:196ce3b4-1074-43bc-a159-329c4e0ad514","Review of Ship Behavior Characteristics in Mixed Waterborne Traffic","Tang, Yingjie (Wuhan University of Technology); Mou, Junmin (Wuhan University of Technology); Chen, Linying (Wuhan University of Technology); Zhou, Y. (TU Delft Rivers, Ports, Waterways and Dredging Engineering)","","2022","Through the continuous development of intellectualization, considering the lifecycle of ships, the future of a waterborne traffic system is bound to be a mixed scenario where intelligent ships of different autonomy levels co-exist, i.e., mixed waterborne traffic. According to the three modules of ships’ perception, decision-making, and execution, the roles of humans and machines under different autonomy levels are analyzed. This paper analyzes and summarizes the intelligent algorithms related to the three modules proposed in the last five years. Starting from the characteristics of the algorithms, the behavior characteristics of ships with different autonomous levels are analyzed. The results show that in terms of information perception, relying on the information perception techniques and risk analysis methods, the ship situation can be judged, and the collision risk is evaluated. The risk can be expressed in two forms, being graphical and numerical. The graphical images intuitively present the risk level, while the numerical results are easier to apply into the control link of ships. In the future, it could be considered to establish a risk perception system with digital and visual integration, which will be more efficient and accurate in risk identification. With respect to intelligent decision-making, currently, unmanned ships mostly use intelligent algorithms to make decisions and tend to achieve both safe and efficient collision avoidance goals in a high-complexity manner. Finally, regarding execution, the advanced power control devices could improve the ship’s maneuverability, and the motion control algorithms help to achieve the real-time control of the ship’s motion state, so as to further improve the speed and accuracy of ship motion control. With the upgrading of the autonomy level, the ship’s behavior develops in a safer, more efficient, and more environment-friendly manner.","Execution; Information perception; Intelligent decision-making; Mixed waterborne traffic; Ship autonomy; Ship behavior","en","review","","","","","","","","","","","Rivers, Ports, Waterways and Dredging Engineering","","",""
"uuid:f0b0f23e-737d-4426-8579-a48b29ce1e35","http://resolver.tudelft.nl/uuid:f0b0f23e-737d-4426-8579-a48b29ce1e35","Optical Characteristics and Fault Diagnosis of Partial Discharge in C4F7N/CO2 Gas mixture and SF6 Based on Novel Multispectral Microarray Detection","Zang, Y. (Shanghai Jiao Tong University); Qian, Yong (Shanghai Jiao Tong University); Zhou, Xiaoli (Fudan University); Ghaffarian Niasar, M. (TU Delft DC systems, Energy conversion & Storage); Sheng, Gehao (Shanghai Jiao Tong University); Jiang, Xiuchen (Shanghai Jiao Tong University)","","2022","Optical partial discharge (PD) detection is an efficient means of diagnosing the insulation status of power equipment. C4F7N/CO2 gas mixture is a very potential environmentally-friendly SF6 substitute gas, and its PD optical characteristics need to be studied to guide the PD diagnosis of novel C4F7N/CO2 equipment. Therefore, this article proposes a multispectral microarray detection technology, which can achieve high-sensitivity detection and PD diagnosis by simultaneously collecting the spectral characteristics of multiple bands. By setting up an experimental platform, the PD experiments of four typical defects in the C4F7N/CO2 gas mixture with five different proportions and pure SF6 are carried out. Based on the analysis of PD multispectral features, the correlation between different gases and the difference between different defects are obtained. Finally, by combining multispectral detection with a t-distributed stochastic neighbor embedding (T-SNE) feature extraction algorithm, a PD diagnosis method that can adapt to both C4F7N/CO2 gas mixture and SF6 is proposed, which provides a reference for the PD detection of novel C4F7N/CO2 equipment application.","C4F7N/CO2 gas mixture; multispectral microarray detection; optical characteristic; Optical sensors; partial discharge; Partial discharges","en","journal article","","","","","","","","","","","DC systems, Energy conversion & Storage","","",""
"uuid:319f01fe-2dfe-4507-89bc-071a629b8db4","http://resolver.tudelft.nl/uuid:319f01fe-2dfe-4507-89bc-071a629b8db4","Efficient Online Globalized Dual Heuristic Programming With an Associated Dual Network","Zhou, Y. (TU Delft Control & Simulation; Universiti Sains Malaysia)","","2022","Globalized dual heuristic programming (GDHP) is the most comprehensive adaptive critic design, which employs its critic to minimize the error with respect to both the cost-to-go and its derivatives simultaneously. Its implementation, however, confronts a dilemma of either introducing more computational load by explicitly calculating the second partial derivative term or sacrificing the accuracy by loosening the association between the cost-to-go and its derivatives. This article aims at increasing the online learning efficiency of GDHP while retaining its analytical accuracy by introducing a novel GDHP design based on a critic network and an associated dual network. This associated dual network is derived from the critic network explicitly and precisely, and its structure is in the same level of complexity as dual heuristic programming critics. Three simulation experiments are conducted to validate the learning ability, efficiency, and feasibility of the proposed GDHP critic design.","Adaptation models; Adaptive critic designs (ACDs); Backpropagation; Complexity theory; Costs; globalized dual heuristic programming; incremental model; Mathematical models; neural networks; Programming; radial basis functions; reinforcement learning (RL).; Task analysis","en","journal article","","","","","","","","2023-12-19","","","Control & Simulation","","",""
"uuid:c1b7f626-4294-498f-ba13-8fc04f7283ba","http://resolver.tudelft.nl/uuid:c1b7f626-4294-498f-ba13-8fc04f7283ba","Rural Post-Earthquake Resettlement Mode Choices: Empirical Case Studies of Sichuan, China","Zhao, Lei (Chengdu University of Technology); Zhou, Sifan (Chengdu University of Technology); Zhong, Jinglin (Chengdu University of Technology); Ao, Yibin (Chengdu University of Technology); Wang, Yan (Sichuan College of Architectural Technology); Wang, T. (TU Delft Design & Construction Management); Chen, Yunfeng (Purdue University)","","2022","Earthquakes occur frequently in rural areas of Sichuan, China, causing huge damage and high mortality. The built environment plays a significant role in providing residents with safe and resilient settlements in such areas. There is yet little research on how rural families in developing countries cope with geological disasters like earthquakes, and how built environmental factors would influence their resettlement choices which would directly affect their quality of life afterward. Urban planning activities should be accompanied by these insights to design and create human-centric resettlements accordingly. In this study, the resettlement choices after three major earthquakes in Sichuan were studied for this reason. Random sampling and face-to-face questionnaire surveys were combined with factor analysis and binary logistic regression to understand the resettlement modes desired by the residents and the influencing factors. The results show that residents who have lived in their current places long and whose houses were not built recently are more likely to choose the in-situ resettlement. Accessibility to employment and public services has a significant impact on residents' choice of in-situ resettlement or reallocated resettlement, and so does the previous resettlement experience. The research results can provide useful suggestions for Chinese rural area post-earthquake resettlement planning following a human-centric approach with empirical data.","post-earthquake resettlement mode; influencing factor; factor analysis; binary logistic regression; Wenchuan earthquake; Changning earthquake; Lushan earthquake","en","journal article","","","","","","","","","","","Design & Construction Management","","",""
"uuid:5dbc5148-f5a7-4102-84c5-f10ca6ff00e3","http://resolver.tudelft.nl/uuid:5dbc5148-f5a7-4102-84c5-f10ca6ff00e3","Effects of biological activated carbon filter running time on disinfection by-product precursor removal","Wang, Feifei (Shanghai University); Pan, Jiazheng (Shanghai University); Hu, Yulin (Shanghai University); Zhou, Jie (Shanghai University); Wang, Haoqian (Shanghai University); Huang, Xin (Shanghai University); Chu, Wenhai (Tongji University); van der Hoek, J.P. (TU Delft Sanitary Engineering; Waternet)","","2022","Biological activated carbon (BAC) filtration is usually considered to be able to decrease formation potentials (FPs) of disinfection by-products (DBPs) in drinking water treatment plant (DWTP). However, BAC filters with long running time may release microbial metabolites to effluents and therefore increase FPs of nitrogenous DBPs with high toxicity. To verify this hypothesis, this study continuously tracked BAC filters in a DWTP for one year, and assessed effects of old (running time 8–9 years) and new (running time 0–13 months) BAC filters on FPs of 15 regulated and unregulated DBPs. Results revealed that dissolved organic carbon (DOC) removal was slightly higher in the new BAC than the old one. All fluorescent components of dissolved organic matter evidently declined after new BAC filtration, but fulvic acid-like and soluble microbial product-like substances increased after old BAC filtration, which could be caused by microbial leakage. Correspondingly, new BAC filter generally removed more DBP FPs than the old one. 46.5% HAA7 FPs from chlorination and 44.3% THM4 FPs from chloramination were removed by new BAC filter. However, some DBP FPs, especially HAN FPs, were poorly removed or even increased by the old BAC filter. Proteobacteria could be a main contributor for DBP precursor removal in BAC filters. Herminiimonas, most abundant genera in new BAC filter, may explain its better DOC and UV254 removal performance and lower DBP FPs, while Bradyrhizobium, most abundant genera in old BAC filter, might produce more extracellular polymeric substances and therefore increased N-DBP FPs in old BAC effluent. This study provided insight into variations of DBP FPs and microbial communities in the new and old BAC filters, and will be helpful for the optimization of DWTP design and operation for public health.","Biological activated carbon; Chlorination; Chloramination; Disinfection by-products; Formation potentials; High-throughput sequencing","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-11-14","","","Sanitary Engineering","","",""
"uuid:dc417e62-58bd-4bd7-b1fc-68662770e36e","http://resolver.tudelft.nl/uuid:dc417e62-58bd-4bd7-b1fc-68662770e36e","Hydrogenated Boron Phosphide with the excellent tunability of electronic properties and Current-Voltage responses","Tan, C. (TU Delft Electronic Components, Technology and Materials; Southern University of Science and Technology; Shenzhen Institute of Wide-bandgap Semiconductors); Zhou, Quan (Chongqing University); Liu, X. (TU Delft Electronic Components, Technology and Materials; Southern University of Science and Technology; Shenzhen Institute of Wide-bandgap Semiconductors); Zhang, Kouchi (TU Delft Electronic Components, Technology and Materials); Ye, H. (Shenzhen Institute of Wide-bandgap Semiconductors; Southern University of Science and Technology; Chongqing University); Wu, Qibao (ShenZhen Institute of Information Technology)","","2022","Combining the first principles calculations and the non-equilibrium Green’s function formalisms, we decipher the structural, electronic, and transport properties of boron phosphide (BP) with hydrogenation. Hydrogenated BP monolayer is an indirect semiconductor with a wide-bandgap of 3.76 eV that is favorable in power devices. We find that the electronic properties are dependent of the stacking orders and the binding strength of the AA-, AB-, and AE-stacked patterns are strongest in the investigated configurations. Under the external E-field, the bandgaps of hydrogenated BP bilayer show a quasi-parabolic function and a feature of the semiconductor-metallic transition. Besides, when we apply a tensile strain on hydrogenated BP bilayer, its bandgap linearly decreases with the increasing of the strain strength along the zigzag and armchair directions. The strain energies further confirm that hydrogenated BP has an excellent characteristic of elastic deformation, being independent of the stacking orders and strain orientation. The transport calculations exhibit various responses to the different two-probe configurations, which indicates that hydrogenated BP possesses the feature of transmission anisotropy. Owing to the nontrivial tunability and transport feature, the hydrogenated BP materials may have tremendous prospects to be applied in micro-/nano-devices with high consumption.","First principles calculations; NEGF; hydrogenation; Boron phosphide; External stimulus; Transport feature","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Electronic Components, Technology and Materials","","",""
"uuid:c46c3186-e2a1-42ac-948b-624d34739e9b","http://resolver.tudelft.nl/uuid:c46c3186-e2a1-42ac-948b-624d34739e9b","Optical Detection Method for Partial Discharge of Printed Circuit Boards in Electrified Aircraft under Various Pressures and Voltages","Zang, Yiming (Shanghai Jiao Tong University); Ghaffarian Niasar, M. (TU Delft DC systems, Energy conversion & Storage); Qian, Yong (Shanghai Jiao Tong University); Zhou, Xiaoli (Fudan University); Sheng, Gehao (Shanghai Jiao Tong University); Jiang, Xiuchen (Shanghai Jiao Tong University); Vaessen, P.T.M. (TU Delft DC systems, Energy conversion & Storage)","","2022","Realization of an electrical aircraft demands a low-weight electric distribution and propulsion system. The use of high voltage and power electronics operated at high switching frequencies is essential to achieve this objective. However, printed circuit boards (PCBs) in electrified aircraft are in a harsh working environment, which can make PCBs more susceptible to generate partial discharges (PDs). The current PD detection technology has poor immunity to the electromagnetic interference and acoustic interference in the operating environment of aircraft. Therefore, this article proposes an optical-based PD detection method for PCBs, which is effectively immune to electromagnetic and acoustic interference. This method uses fluorescent fiber as a PD optical signal sensor and then collects the optical signal by the avalanche photodiode (APD). Experiments have verified that the detection sensitivity, sensing range, and anti-interference performance of this method are well satisfied with the PD detection. In addition, single PD pulse, optical phase resolved PD (PRPD) patterns, and PD inception voltage (PDIV) under different air pressure and voltage conditions are investigated. Finally, the relationship between the optical signal and PD amplitude is found to be proportional, which proves that the severity of the PD on PCBs can be effectively detected and evaluated by this method.","partial discharge; printed circuit boards; optical detection; electrified aircraft; fluorescent fiber","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","DC systems, Energy conversion & Storage","","",""
"uuid:9da909a0-69c7-461b-937b-cb94ea8efeec","http://resolver.tudelft.nl/uuid:9da909a0-69c7-461b-937b-cb94ea8efeec","Semi-automated digital workflow to design and evaluate patient-specific mandibular reconstruction implants","van Kootwijk, A. (Student TU Delft); Moosabeiki, Vahid (TU Delft Biomaterials & Tissue Biomechanics); Cruz Saldivar, M. (TU Delft Biomaterials & Tissue Biomechanics); Pahlavani, H. (TU Delft Biomaterials & Tissue Biomechanics); Leeflang, M.A. (TU Delft Biomaterials & Tissue Biomechanics); Kazemivand Niar, S. (Tarbiat Modares University); Tümer, N. (TU Delft Biomaterials & Tissue Biomechanics); Mirzaali, Mohammad J. (TU Delft Biomaterials & Tissue Biomechanics); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2022","The reconstruction of large mandibular defects with optimal aesthetic and functional outcomes remains a major challenge for maxillofacial surgeons. The aim of this study was to design patient-specific mandibular reconstruction implants through a semi-automated digital workflow and to assess the effects of topology optimization on the biomechanical performance of the designed implants. By using the proposed workflow, a fully porous implant (LA-implant) and a topology-optimized implant (TO-implant) both made of Ti-6Al-4V ELI were designed and additively manufactured using selective laser melting. The mechanical performance of the implants was predicted by performing finite element analysis (FEA) and was experimentally assessed by conducting quasi-static and cyclic biomechanical tests. Digital image correlation (DIC) was used to validate the FE model by comparing the principal strains predicted by the FEM model with the measured distribution of the same type of strain. The numerical predictions were in good agreement with the DIC measurements and the predicted locations of specimen failure matched the actual ones. No statistically significant differences (p < 0.05) in the mean stiffness, mean ultimate load, or mean ultimate displacement were detected between the LA- and TO-implant groups. No implant failures were observed during quasi-static or cyclic testing under masticatory loads that were substantially higher (>1000 N) than the average maximum biting force of healthy individuals. Given its relatively lower weight (16.5%), higher porosity (17.4%), and much shorter design time (633.3%), the LA-implant is preferred for clinical application. This study clearly demonstrates the capability of the proposed workflow to develop patient-specific implants with high precision and superior mechanical performance, which will greatly facilitate cost- and time-effective pre-surgical planning and is expected to improve the surgical outcome.","Biomechanical validation; Finite element analysis; Implant design workflow; Mandibular reconstruction; Patient-specific implant; Topology optimization","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:5e5022f8-2ee1-4803-9716-37d0ca5c399a","http://resolver.tudelft.nl/uuid:5e5022f8-2ee1-4803-9716-37d0ca5c399a","Electron-Irradiation-Induced Degradation of Transfer Characteristics in Super-Junction VDMOSFET","Jiang, Jing (Fudan University); Wang, S. (TU Delft Bio-Electronics; Southern University of Science and Technology); Liu, X. (TU Delft Interactive Intelligence; Southern University of Science and Technology); Liu, Jianhui (Sky Chip Interconnection Technology Co); Li, Jun (Sky Chip Interconnection Technology Co); Zhou, Dexiang (Sky Chip Interconnection Technology Co); Zhang, Kouchi (TU Delft Electronic Components, Technology and Materials); Ye, H. (TU Delft Electronic Components, Technology and Materials; Southern University of Science and Technology; Chongqing University); Tan, C. (TU Delft Electronic Components, Technology and Materials; Chongqing University)","","2022","High electric-field stress is an effective solution to the recovery of irradiated devices. In this paper, the dependence of the recovery level on the magnitude of gate voltage and duration is investigated. Compared with the scheme of high gate-bias voltage with a short stress time, the transfer characteristics are significantly recovered by applying a low electric field with a long duration. When the electric field and stress time are up to a certain value, the threshold voltage almost approaches the limitation, which is less than that before irradiation. Meanwhile, the effect of temperature on the recovery of the irradiated devices is also demonstrated. The result indicates that a high temperature of 175 °C used for the irradiated devices’ annealing does not play a role in promoting the recovery of transfer characteristics. In addition, to obtain a deep-level understanding of threshold degradation, the first-principles calculations of three Si/SiO2 interfaces are performed. It is found that new electronic states can be clearly observed in the conduction bans and valence bands after the Si-H/-OH bonds are broken by electron irradiation. However, their distribution depends on the selection of the passivation scheme. Ultimately, it can be observed that the threshold voltage linearly decreases with the increase in interface charge density. These results can provide helpful guidance in the deep interpretation of threshold degradation and the recovery of the irradiated super-junction devices.","electron irradiation; transfer characteristics; degradation; Si/SiO2 interface; first-principles calculation; interface charge density; threshold variation","en","journal article","","","","","","","","","","","Bio-Electronics","","",""
"uuid:31a8a4d3-652f-464d-bda5-d9b5de2e9be2","http://resolver.tudelft.nl/uuid:31a8a4d3-652f-464d-bda5-d9b5de2e9be2","Platform Development of BIM-Based Fire Safety Management System Considering the Construction Site","Yang, Yapin (Hunan University); Sun, Ying (Concordia University); Chen, Mingsi (Hunan University); Zhou, Yuekuan (The Hong Kong Polytechnic University; The Hong Kong University of Science and Technology); Wang, Ran (Hunan University); Liu, Zhengxuan (TU Delft Design & Construction Management; Hunan University)","","2022","Fire at a construction site usually results in serious accidents. Therefore, fire management at the construction site is critical to decreasing possible accidents. However, conventional fire safety management can be problematic in many aspects, such as visualization, multi-stage alarm systems, and dynamic escape route optimization. To solve these issues, this paper develops a platform for a BIM-based fire safety management system that considers the construction site. The developed platform contains four subsystems: a remote monitoring subsystem, a fire visualization subsystem, a multi-stage fire alarm subsystem, and an escape route optimization subsystem. It detects the fire hazard in the early stage of the fire by the remote monitoring subsystem and transmits this information to the fire visualization subsystem for displaying. Furthermore, the multi-stage fire alarm subsystem sends warnings or alarms based on the fire’s severity. Moreover, the escape route optimization subsystem dynamically optimizes the evacuation routes by considering the actual number of people at the construction site and the potential crowding as people pass through the escapeway. Results show that this system can provide informative and on-time fire protection measures to different participants at the construction site. This study can also serve as a solution to improve fire safety management at the construction site.","construction site; fire safety management; BIM technology; escape route optimization; visualization","en","journal article","","","","","","","","","","","Design & Construction Management","","",""
"uuid:ead36177-821d-4233-a014-71f860d662fd","http://resolver.tudelft.nl/uuid:ead36177-821d-4233-a014-71f860d662fd","Deep Deterministic Policy Gradient for High-Speed Train Trajectory Optimization","Ning, Lingbin (Beijing Jiaotong University); Zhou, Min (Beijing Jiaotong University); Hou, Zhuopu (Beijing Jiaotong University); Goverde, R.M.P. (TU Delft Transport and Planning); Wang, Fei Yue (Chinese Academy of Sciences); Dong, Hairong (Beijing Jiaotong University)","","2022","This paper proposes a novel train trajectory optimization approach for high-speed railways. We restrict our attention to single train operation scenarios with different scheduled/rescheduled running times aiming at generating optimal train recommended trajectories in real time, which can ensure punctuality and energy efficiency of train operation. A learning-based approach deep deterministic policy gradient (DDPG) is designed to generate optimal train trajectories based on the offline training from the interaction between the agent and the trajectory simulation environment. An allocating running time and selecting operation modes (ARTSOM) algorithm is proposed to improve train punctuality and give a series of discrete operation modes (full traction, cruising, coasting, full braking), and thus to produce a feasible training set for DDPG, which can speed up the training process. Numerical experiments show that an optimized speed profile can be generated by DDPG within seconds on a realistic railway line. In addition, the results demonstrate the generalization ability of trained DDPG in solving TTO problems with different running times and line conditions.","deep deterministic policy gradient; energy efficiency; High-speed railway; train trajectory optimization","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Transport and Planning","","",""
"uuid:8f892dbc-d17b-46ab-b9b9-e7478b8c9d0c","http://resolver.tudelft.nl/uuid:8f892dbc-d17b-46ab-b9b9-e7478b8c9d0c","Additive Manufacturing of Biomaterials: Design Principles and Their Implementation","Mirzaali, Mohammad J. (TU Delft Biomaterials & Tissue Biomechanics); Moosabeiki, Vahid (TU Delft Biomaterials & Tissue Biomechanics); Rajaai, S.M. (TU Delft Biomaterials & Tissue Biomechanics); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2022","Additive manufacturing (AM, also known as 3D printing) is an advanced manufacturing technique that has enabled progress in the design and fabrication of customised or patient-specific (meta-)biomaterials and biomedical devices (e.g., implants, prosthetics, and orthotics) with complex internal microstructures and tuneable properties. In the past few decades, several design guidelines have been proposed for creating porous lattice structures, particularly for biomedical applications. Meanwhile, the capabilities of AM to fabricate a wide range of biomaterials, including metals and their alloys, polymers, and ceramics, have been exploited, offering unprecedented benefits to medical professionals and patients alike. In this review article, we provide an overview of the design principles that have been developed and used for the AM of biomaterials as well as those dealing with three major categories of biomaterials, i.e., metals (and their alloys), polymers, and ceramics. The design strategies can be categorised as: library-based design, topology optimisation, bio-inspired design, and meta-biomaterials. Recent developments related to the biomedical applications and fabrication methods of AM aimed at enhancing the quality of final 3D-printed biomaterials and improving their physical, mechanical, and biological characteristics are also highlighted. Finally, examples of 3D-printed biomaterials with tuned properties and functionalities are presented.","additive manufacturing; biomaterials; metals; polymers; ceramics","en","review","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:83270c60-8335-4bf4-ab17-73295c7b6690","http://resolver.tudelft.nl/uuid:83270c60-8335-4bf4-ab17-73295c7b6690","ArduPilot-Based Adaptive Autopilot: Architecture and Software-in-The-Loop Experiments","Baldi, S. (TU Delft Team Bart De Schutter; Southeast University); Sun, Danping (Wuhan Textile University; Hubei Electrical Machinery and Control System Engineering Technology Research Center); Xia, Xin (Southeast University); Zhou, Guopeng (Hubei Electrical Machinery and Control System Engineering Technology Research Center); Liu, Di (Southeast University; Rijksuniversiteit Groningen)","","2022","This article presents an adaptive method for ArduPilot-based autopilots of fixed-wing unmanned aerial vehicles (UAVs). ArduPilot is a popular open-source unmanned vehicle software suite. We explore how to augment the PID loops embedded inside ArduPilot with a model-free adaptive control method. The adaptive augmentation, adopted for both attitude and total energy control, uses input/output data without requiring an explicit model of the UAV. The augmented architecture is tested in a software-in-The-loop UAV platform in the presence of several uncertainties (unmodeled low-level dynamics, different payloads, time-varying wind, and changing mass). The performance is measured in terms of tracking errors and control efforts of the attitude and total energy control loops. Extensive experiments with the original ArduPilot, the proposed augmentation, and alternative autopilot strategies show that the augmentation can significantly improve the performance for all payloads and wind conditions: The UAV is less affected by wind and exhibits more than 70% improved tracking, with more than 7% reduced control effort.","ArduPilot; attitude control; autopilot; model-free adaptive control; total energy control; unmanned aerial vehicle (UAV)","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Team Bart De Schutter","","",""
"uuid:818bc40d-e714-4f48-a254-7e9dfe7c3718","http://resolver.tudelft.nl/uuid:818bc40d-e714-4f48-a254-7e9dfe7c3718","Preventing Antibiotic-Resistant Infections: Additively Manufactured Porous Ti6Al4V Biofunctionalized with Ag and Fe Nanoparticles","Putra, N.E. (TU Delft Biomaterials & Tissue Biomechanics); Leeflang, M.A. (TU Delft Biomaterials & Tissue Biomechanics); Ducret, Verena (University of Geneva); Patrulea, Viorica (University of Oxford); Fratila-Apachitei, E.L. (TU Delft Biomaterials & Tissue Biomechanics); Perron, Karl (University of Geneva); Ye, Hua (University of Oxford); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Apachitei, I. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2022","Implant-associated infections are highly challenging to treat, particularly with the emergence of multidrug-resistant microbials. Effective preventive action is desired to be at the implant site. Surface biofunctionalization of implants through Ag-doping has demonstrated potent antibacterial results. However, it may adversely affect bone regeneration at high doses. Benefiting from the potential synergistic effects, combining Ag with other antibacterial agents can substantially decrease the required Ag concentration. To date, no study has been performed on immobilizing both Ag and Fe nanoparticles (NPs) on the surface of additively manufactured porous titanium. We additively manufactured porous titanium and biofunctionalized its surface with plasma electrolytic oxidation using a Ca/P-based electrolyte containing Fe NPs, Ag NPs, and the combinations. The specimen’s surface morphology featured porous TiO2 bearing Ag and Fe NPs. During immersion, Ag and Fe ions were released for up to 28 days. Antibacterial assays against methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa showed that the specimens containing Ag NPs and Ag/Fe NPs exhibit bactericidal activity. The Ag and Fe NPs worked synergistically, even when Ag was reduced by up to three times. The biofunctionalized scaffold reduced Ag and Fe NPs, improving preosteoblasts proliferation and Ca-sensing receptor activation. In conclusion, surface biofunctionalization of porous titanium with Ag and Fe NPs is a promising strategy to prevent implant-associated infections and allow bone regeneration and, therefore, should be developed for clinical application.","antibiotic-resistant bacteria; implant-associated infection; surface biofunctionalization; additive manufacturing; antibacterial; iron nanoparticles; silver nanoparticles","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:17487f41-b96a-4063-a64f-9760ff465c17","http://resolver.tudelft.nl/uuid:17487f41-b96a-4063-a64f-9760ff465c17","Measuring Bed Exchange Properties of Cohesive Sediments Using Tripod Data","Zhou, Z. (TU Delft Coastal Engineering; East China Normal University); Ge, Jianzhong (Shanghai Estuarine and Coastal Science Research Center; Institute of Eco-Chongming (IEC); East China Normal University); van Maren, D.S. (TU Delft Environmental Fluid Mechanics; East China Normal University; Deltares); Gu, Jinghua (East China Normal University); Ding, Pingxing (East China Normal University); Wang, Zhengbing (TU Delft Coastal Engineering; Deltares)","","2022","The Krone–Partheniades (K-P) framework has been used for decades to quantify and analyze the sediment exchange at a water–bed interface. Measuring the erosion and deposition parameters that are part of this framework requires time-consuming field observations. Additionally, the erosion parameters are measured independently of deposition parameters, while in reality they are coupled. In numerical models applying the K-P framework these parameters are often assumed to be constant in time and mutually independent. In this study, we develop a relatively simple methodology to determine the erosion and deposition parameters, using conventional near-bed observations of bed level, sediment concentration and flow velocity. This methodology is subsequently applied to tripod observations collected in the Changjiang estuary, China, to compute continuous time-varying erosion and settling parameters. We propose a diagram to visualize the interdependency and accuracy of erosion and deposition parameters, which is the input for K-P framework models requiring this interdependency","Krone–Partheniades equations; observations techniques; settling velocity; critical shear stress","en","journal article","","","","","","","","","","","Coastal Engineering","","",""
"uuid:aa5aa602-d6c9-4657-9321-9946a85c0fee","http://resolver.tudelft.nl/uuid:aa5aa602-d6c9-4657-9321-9946a85c0fee","Near-surface Monitoring of CO2 Storage Sites: Case Study from CaMI FRS","Butcher, A. (University of Bristol); Zhou, W. (TU Delft Applied Geophysics and Petrophysics); Kendall, J. (University of Oxford); Stork, A. (Silixa); Vandeweijer, V. (TNO); Macquet, M. (University of Calgary); Lawton, D. (University of Calgary)","","2022","","","en","conference paper","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Applied Geophysics and Petrophysics","","",""
"uuid:cb074e80-4f75-41d9-906a-b907d21d992b","http://resolver.tudelft.nl/uuid:cb074e80-4f75-41d9-906a-b907d21d992b","Designing living artefacts: Opportunities and challenges for biodesign","Kim, Raphael (TU Delft Materials and Manufacturing); Zhou, J. (Student TU Delft); Groutars, E.G. (TU Delft Mechatronic Design; Avans University of Applied Sciences); Karana, E. (TU Delft Emerging Materials)","","2022","Biodesign is an emerging form of design practice integrating biological materials and processes, and there is a growing interest in the field for structured conversations to generate insights on how it can be best taught, researched, and disseminated. In our conversations, we began exploring biodesign under the framework of Living Artefacts, in which livingness is prolonged to the use time of artefacts, and understood as a biological, ecological, and experiential phenomenon. Two researchers investigating Living Artefacts, through their short show-and-tell presentations, initiated threads of moderated open discussions. Using the Living Artefacts framework as a departure point, we collectively explored opportunities and challenges in biodesign, and possible ways in which they could be addressed.","biodesign; living artefacts; living aesthetics; habitabilities; microorganisms","en","conference paper","","","","","","","","","","","Materials and Manufacturing","","",""
"uuid:f7b9783d-4c15-4180-b626-0eb3acc8ab66","http://resolver.tudelft.nl/uuid:f7b9783d-4c15-4180-b626-0eb3acc8ab66","Habitabilities of Living Artefacts: A Taxonomy of Digital Tools for Biodesign","Zhou, J. (TU Delft BN/Marie-Eve Aubin-Tam Lab; TU Delft Mechatronic Design); Barati, B. (TU Delft Emerging Materials; Eindhoven University of Technology); Giaccardi, Elisa (TU Delft Human Information Communication Design); Karana, E. (TU Delft Emerging Materials)","","2022","This paper offers a taxonomy of digital tools for crafting habitabilities in biodesign practices. Over the past decade, interest has grown among design and Human-Computer Interaction (HCI) scholars to explore the potentials of living organisms for novel responsive behavior and interaction possibilities. Yet, to date, it remains unexplored how digital technologies can support the design of living artefacts, that is, artefacts in which the organism is alive at the time of use. Our taxonomy bridges this gap by examining and reinterpreting the roles existing digital tools can play in the exploration of the abilities of things to provide a habitat for living artefacts both at design time and use time, i.e., crafting habitabilities in biodesign. The taxonomy is grounded in a systematic analysis of ten cases of living artefacts from art, design, and HCI, and it identifies three roles for digital tools: understanding, embodying, and perpetuating the habitat. Forwarding a relational perspective through the lens of habitability, this work promotes the mutual wellbeing of both humans and non-humans in biodesign.","Biodesign; Biological HCI; Living Artefacts; Living Materials; More-than-Human Design","en","journal article","","","","","","","","","","","BN/Marie-Eve Aubin-Tam Lab","","",""
"uuid:f65b65e3-7e96-4adb-8b25-1d364f8f71e7","http://resolver.tudelft.nl/uuid:f65b65e3-7e96-4adb-8b25-1d364f8f71e7","Using Eye-Tracking Data to Predict Situation Awareness in Real Time During Takeover Transitions in Conditionally Automated Driving","Zhou, Feng (University of Michigan-Dearborn); Yang, X. Jessie (University of Michigan); de Winter, J.C.F. (TU Delft Human-Robot Interaction)","","2022","Situation awareness (SA) is critical to improving takeover performance during the transition period from automated driving to manual driving. Although many studies measured SA during or after the driving task, few studies have attempted to predict SA in real time in automated driving. In this work, we propose to predict SA during the takeover transition period in conditionally automated driving using eye-tracking and self-reported data. First, a tree ensemble machine learning model, named LightGBM (Light Gradient Boosting Machine), was used to predict SA. Second, in order to understand what factors influenced SA and how, SHAP (SHapley Additive exPlanations) values of individual predictor variables in the LightGBM model were calculated. These SHAP values explained the prediction model by identifying the most important factors and their effects on SA, which further improved the model performance of LightGBM through feature selection. We standardized SA between 0 and 1 by aggregating three performance measures (i.e., placement, distance, and speed estimation of vehicles with regard to the ego-vehicle) of SA in recreating simulated driving scenarios, after 33 participants viewed 32 videos with six lengths between 1 and 20 s. Using only eye-tracking data, our proposed model outperformed other selected machine learning models, having a root-mean-squared error (RMSE) of 0.121, a mean absolute error (MAE) of 0.096, and a 0.719 correlation coefficient between the predicted SA and the ground truth. The code is available at https://github.com/refengchou/Situation-awareness-prediction. Our proposed model provided important implications on how to monitor and predict SA in real time in automated driving using eye-tracking data.","Atmospheric measurements; automated driving; explainability.; eye-tracking measures; Particle measurements; Predictive models; Real-time situation awareness prediction; Real-time systems; takeover; Task analysis; Time measurement; Vehicles","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2021-10-06","","","Human-Robot Interaction","","",""
"uuid:01128df0-d17b-4182-939f-893ebf6b6555","http://resolver.tudelft.nl/uuid:01128df0-d17b-4182-939f-893ebf6b6555","Morphodynamic changes in the Yangtze Estuary under the impact of the Three Gorges Dam, estuarine engineering interventions and climate-induced sea level rise","Cheng, H. Q. (East China Normal University; Institute of Eco-Chongming (IEC)); Chen, W. (Helmholtz-Zentrum Geesthacht - Zentrum für Material- und Küstenforschung GmbH); Li, J. F. (East China Normal University; Institute of Eco-Chongming (IEC)); Jiang, Y. H. (China Geological Survey); Hu, X. (Shanghai Chengtou Group Corporation); Zhang, X. L. (Shanghai Municipal Planning and Natural Resources Bureau); Zhou, F. N. (Changjiang Water Resources Commission); Hu, F. X. (East China Normal University); Stive, M.J.F. (TU Delft Coastal Engineering)","","2022","The estuarine turbidity maximum (ETM) in the Yangtze Estuary Delta (YED) is muddy by definition and lacks bottom undulations. However, since 2013, a remarkable change has occurred in the YED. Recent images detected by a multibeam echosounder system, SeaBat 7125, for the first time have confirmed widespread regions of subaqueous dunes in the Yangtze ETM channel. This abnormal change is the result of morphodynamic transformation from the combination of an abrupt decline in sediment supply resulting from the construction of the Three Gorges Dam (TGD) and hydrodynamic changes caused by sea level rise. The latter includes anthropogenic-induced sea level rises (from land subsidence and coastal engineering) of 7–37 cm and a climate-induced sea level rise of 8 cm during the past four decades. Obvious evidence of hydrodynamic changes includes tidal amplification, i.e., a 10–28 cm rise in the tidal range, 42–65 cm rise in the lowest tidal level in the dry season, 45–67 cm rise in the highest tidal level in the flood season and 10–30% increase in the amplitude of the major tidal component. These findings will likely have global implications in formulating strategies to combat the superimposed effects of human interventions and climate change on upstream river and downstream coastal developments.","estuarine turbidity maxima; sea level rise; subaqueous dunes; tidal amplification; Yangtze Estuary","en","journal article","","","","","","","","","","","Coastal Engineering","","",""
"uuid:5f61f491-9db0-4f8a-b2ad-554045bbc6d8","http://resolver.tudelft.nl/uuid:5f61f491-9db0-4f8a-b2ad-554045bbc6d8","Extrusion-based additive manufacturing of Mg-Zn alloy scaffolds","Dong, J. (TU Delft Biomaterials & Tissue Biomechanics); Tümer, N. (TU Delft Biomaterials & Tissue Biomechanics); Leeflang, M.A. (TU Delft Biomaterials & Tissue Biomechanics); Taheri, P. (TU Delft Team Peyman Taheri); Fratila-Apachitei, E.L. (TU Delft Biomaterials & Tissue Biomechanics); Mol, J.M.C. (TU Delft Team Arjan Mol); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2022","Porous biodegradable Mg and its alloys are considered to have a great potential to serve as ideal bone substitutes. The recent progress in additive manufacturing (AM) has prompted its application to fabricate Mg scaffolds with geometrically ordered porous structures. Extrusion-based AM, followed by debinding and sintering, has been recently demonstrated as a powerful approach to fabricating such Mg scaffolds, which can avoid some crucial problems encountered when applying powder bed fusion AM techniques. However, such pure Mg scaffolds exhibit a too high rate of in vitro biodegradation. In the present research, alloying through a pre-alloyed Mg-Zn powder was ultilized to enhance the corrosion resistance and mechanical properties of AM geometrically ordered Mg-Zn scaffolds simultaneously. The in vitro biodegradation behavior, mechanical properties, and electrochemical response of the fabricated Mg-Zn scaffolds were evaluated. Moreover, the response of preosteoblasts to these scaffolds was systematically evaluated and compared with their response to pure Mg scaffolds. The Mg-Zn scaffolds with a porosity of 50.3% and strut density of 93.1% were composed of the Mg matrix and MgZn2 second phase particles. The in vitro biodegradation rate of the Mg-Zn scaffolds decreased by 81% at day 1, as compared to pure Mg scaffolds. Over 28 days of static immersion in modified simulated body fluid, the corrosion rate of the Mg-Zn scaffolds decreased from 2.3 ± 0.9 mm/y to 0.7 ± 0.1 mm/y. The yield strength and Young's modulus of the Mg-Zn scaffolds were about 3 times as high as those of pure Mg scaffolds and remained within the range of those of trabecular bone throughout the biodegradation tests. Indirect culture of MC3T3-E1 preosteoblasts in Mg-Zn extracts indicated favorable cytocompatibility. In direct cell culture, some cells could spread and form filopodia on the surface of the Mg-Zn scaffolds. Overall, this study demonstrates the great potential of the extrusion-based AM Mg-Zn scaffolds to be further developed as biodegradable bone-substituting biomaterials.","Additive manufacturing; Biodegradation; Magnesium-zinc alloy; Material extrusion; Porous scaffold","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:5df90966-44ab-41ef-a011-f776749d0d54","http://resolver.tudelft.nl/uuid:5df90966-44ab-41ef-a011-f776749d0d54","GPR-assisted evaluation of probabilistic fatigue crack growth in rib-to-deck joints in orthotropic steel decks considering mixed failure models","Heng, J. (TU Delft Steel & Composite Structures; Shenzhen University); Zhou, Zhixiang (Shenzhen University); Zou, Yang (Chongqing Jiaotong University); Kaewunruen, Sakdirat (University of Birmingham)","","2022","Rib-to-deck (RD) welded joints in orthotropic steel decks (OSDs) of bridges demonstrates two major fatigue failure models, including the toe-to-deck (TTD) cracking and root-to-deck (RTD) cracking. Generally, the sole failure model is employed in the fatigue assessment of RD joints, causing a hot dispute on the dominant failure model. In this paper, the fatigue crack growth (FCG) in RD joints has been evaluated considering uncertainties and mixed failure models. A probabilistic fatigue crack growth (PFCG) model is at first established for the RD joint, in which two crack-like initial flaws are assumed at the weld toe and root of the RD joint. After that, the gaussian process regression is used to assist and boost the PFCG simulation. Then, the PFCG model is implemented on a typical OSD with the random traffic model. Finally, the result of the PFCG model is discussed in detail, including the failure model, fatigue reliability and life prediction, and crack size evolution. It is revealed that both the TTD and RTD cracking models have a notable contribution to fatigue failure and could not be ignored. More crucial, a remarkable reduction can be observed in the fatigue reliability of RD joints when considering mixed failure models. This study not only highlights the influence of mixed failure models on the fatigue performance of welded joints, but also provide an insight into the application of novel machine learning tools in solving the traditional structural issue.","Gaussian process regression; Mixed failure models; Orthotropic steel deck; Probabilistic fatigue crack growth; Rib-to-deck joint","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Steel & Composite Structures","","",""
"uuid:968c2d5b-3a0d-493e-aca6-f6b46c1c736b","http://resolver.tudelft.nl/uuid:968c2d5b-3a0d-493e-aca6-f6b46c1c736b","A hybrid methodology for structural damage detection uniting FEM and 1D-CNNs: Demonstration on typical high-pile wharf: Demonstration on typical high-pile wharf","Zhou, Yujue (Sanming University; Tongji University); Zheng, Yonglai (Tongji University); Liu, Yongcheng (Tongji University); Pan, Tanbo (Tongji University); Zhou, Y. (TU Delft Applied Mechanics)","","2022","Vibration-based structural damage detection (SDD) has been a subject of intense research in structural health monitoring (SHM) for large civil engineering structures over the decades. The performance of the conventional SDD approaches predominantly relies on the rational choices of the damage feature and classifier. Hand-crafted features or fixed classifiers would not be the optimal choice for all structural damaged scenarios. This paper proposes a novel, quick and precise real-time SDD framework for high-pile wharf foundations using a combination of finite element modeling and 1D convolutional neural networks (CNNs). The distinct advantage of this method lies in extracting the damage-related features from the raw displacement response directly and automatically, and the computational complexity of the compact 1D CNNs is significantly lower because the data processing involves only simple 1D operations. The results show that the presented 1D CNNs have a superior ability to accurately identify the occurrence and location of damage in real time. In addition, the comprehensive performance of the CNNs trained by the displacement response dataset in component form is significantly better than that based on the dataset in absolute value form. The results also demonstrated that although the proposed CNNs are more sensitive to the longitudinal and lateral displacement responses of the high-pile wharf structure, the vertical component still has a positive effect on the improvement of the generalization and robustness of the CNNs.","1D Convolutional neural networks; Finite element modeling; High-pile wharf; Pile foundations; Structural damage detection; Structural health monitoring; Vibration","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Applied Mechanics","","",""
"uuid:39507656-c011-4558-a0da-ba3280410ac7","http://resolver.tudelft.nl/uuid:39507656-c011-4558-a0da-ba3280410ac7","Poly(2-ethyl-2-oxazoline) coating of additively manufactured biodegradable porous iron","Putra, N.E. (TU Delft Biomaterials & Tissue Biomechanics); Tigrine, A. (Avroxa B.V., Ghent); Aksakal, S. (Avroxa B.V., Ghent); de la Rosa, V. R. (Avroxa B.V., Ghent); Taheri, P. (TU Delft Team Peyman Taheri); Fratila-Apachitei, E.L. (TU Delft Biomaterials & Tissue Biomechanics); Mol, J.M.C. (TU Delft Team Arjan Mol); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2022","Additively manufacturing of porous iron offers a unique opportunity to increase its biodegradation rate by taking advantage of arbitrarily complex porous structures. Nevertheless, achieving the required biodegradation profile remains challenging due to the natural passivation of iron that decrease the biodegradation rate. Moreover, the biocompatibility of iron is reported to be limited. Here, we address both challenges by applying poly(2-ethyl-2-oxazoline) coating to extrusion-based 3D printed porous iron. We characterized the specimens by performing in vitro biodegradation, electrochemical measurements, time-dependent mechanical tests, and in vitro cytocompatibility assays. The coated porous iron exhibited a biodegradation rate that was 2.6× higher than that of non-coated counterpart and maintained the bone-mimicking mechanical properties throughout biodegradation. Despite the formation of dense biodegradation products, the coating ensured a relatively stable biodegradation (i.e., 17% reduction in the degradation rate between days 14 and 28) as compared to that of non-coated specimens (i.e., 43% drop). Furthermore, the coating could be identified even after biodegradation, demonstrating the longevity of the coating. Finally, the coated specimens significantly increased the viability and supported the attachment and growth of preosteoblasts. Our results demonstrate the great potential of poly(2-ethyl-2-oxazoline) coating for addressing the multiple challenges associated with the clinical adoption of porous iron.","Biodegradable; Bone substitution; Extrusion-based 3D printing; iron; Poly(2-ethyl-2-oxazoline) coating; Scaffold","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:7d00389e-f244-402c-8de3-c48c2ac1aba3","http://resolver.tudelft.nl/uuid:7d00389e-f244-402c-8de3-c48c2ac1aba3","Quantifying spatial reallocation of land use/land cover categories in West Africa","Asenso Barnieh, Beatrice (Chinese Academy of Sciences; University of Chinese Academy of Sciences; University of Energy and Natural Resources); Jia, Li (Chinese Academy of Sciences); Menenti, M. (TU Delft Optical and Laser Remote Sensing; Chinese Academy of Sciences); Jiang, Min (Chinese Academy of Sciences); Zhou, Jie (Central China Normal University); Lv, Yunzhe (Chinese Academy of Sciences; University of Chinese Academy of Sciences); Zeng, Yelong (Chinese Academy of Sciences; University of Chinese Academy of Sciences); Bennour, Ali (Chinese Academy of Sciences; University of Chinese Academy of Sciences; Commissariat Regional au Development Agricole)","","2022","Past Land Use Land Cover (LULC) transitions analysis at the sub-continental scale of West Africa revealed spatial reallocation, i.e., simultaneous losses and gains of the LULC categories at different locations. We applied the component analysis approach to separate the total change into three major components, i.e., quantity (net change), exchange and shift (allocation change) as a way to analyse such spatial reallocation and identify the paired categories that accounted for the largest exchange and shift through time. Quantity change is the absolute value of the category's gross gains minus the category's gross losses. An exchange occurs when for example, a natural vegetation patch evolves to cropland at a location concurrently with an equal extent of cropland evolving into natural vegetation at a different location. A shift occurs when the LULC categories involved in the exchange are more than two. The amount of exchange and shift and locations that these exchanges occurred are very useful information for land policies appraisal and the long term contested re-greening of Africa as it may signal simultaneous regrowth and degradation of natural vegetation at different locations in the same landscape and also possible misclassification errors. The results revealed large exchanges in the landscape of West Africa between 1975 and 2000 for arid and humid eco-regions in West Africa. Overall, the exchange and shift components between wetland, water bodies and some other LULC categories such as forestland, other vegetation and cropland were the highest. The exchange between natural vegetation and cropland was considerable, which confirms regrowth despite the massive degradation revealed by the previous studies. Here, the large exchange in 1975–2000 highlighted large spatial reallocation of the LULC categories. The highest net change was experienced in the period between 2000 and 2013 at all spatial aggregations. Settlement and cropland experienced the highest positive net change whilst forestland and other vegetation experienced the highest negative net change. Shift was absent in the category of settlements indicating persistence over time. This analysis provided useful information on the contested re-greening of West Africa.","Exchange; LULC transitions; Net change; Shift; Spatial reallocation; West Africa","en","journal article","","","","","","","","","","","Optical and Laser Remote Sensing","","",""
"uuid:1bf09dee-f2ac-4b22-97c2-ad0c2a3a3aa7","http://resolver.tudelft.nl/uuid:1bf09dee-f2ac-4b22-97c2-ad0c2a3a3aa7","Health diagnosis of bus operation based on multi-source data","Zhou, Xuemei (Tongji University); Guan, Zhen (Tongji University); Pang, Y. (TU Delft Transport Engineering and Logistics); Ji, Xiangfeng (Qingdao University of Technology); Lin, Xiaodan (Tongji University)","","2022","Based on the multi-source data available for bus operations, this paper proposes a health diagnosis system for single-line bus operation systems from two aspects: The operation efficiency and stability. Firstly, the index weight has been defined and calculated based on the Entropy Method. The composite index of bus operation has been obtained, and the health classification standards that pertain to efficient and effective bus operations have also been constructed (Very Healthy, Healthy, Sub-Healthy, and Unhealthy). Secondly, the more efficient machine learning method has been used in order to establish the classification algorithm training set. The effect of the k-Nearest Neighbour and Decision Tree Classification Model has also been compared and analysed in this particular study. Finally, a bus line in Foshan is taken as a case study to verify the effectiveness of the method. This paper can effectively improve the diagnosis efficiency and accuracy by introducing the artificial intelligence algorithm into bus operation diagnosis. It provides a foundation for the development of bus operation health diagnosis decision support system with the function of “bus disease” prevention and treatment.","","en","journal article","","","","","","","","","","","Transport Engineering and Logistics","","",""
"uuid:1cfb6b33-55e4-4f70-8b6e-28fa004904a5","http://resolver.tudelft.nl/uuid:1cfb6b33-55e4-4f70-8b6e-28fa004904a5","Revealing the influence of Mo addition on interphase precipitation in Ti-bearing low carbon steels","Dong, Haokai (Tsinghua University; South China University of Technology); Chen, Hao (Tsinghua University); Riyahi khorasgani, Ahmadreza (Center for Interface-Dominated High Performance Materials); Zhang, Boning (Tsinghua University); Zhang, Yongjie (Tohoku University); Wang, Zhenqiang (Harbin Engineering University); Zhou, Xiaosheng (Tsinghua University); Wang, Wei (Baosteel Research Institute); van der Zwaag, S. (TU Delft Novel Aerospace Materials; Tsinghua University)","","2022","Mo is widely used as an effective microalloying element to improve mechanical performance of interphase precipitation steels, but the precise role of Mo in interphase precipitation behavior is not fully understood. In this contribution, interphase precipitation behavior in a series of Ti-Mo-bearing low carbon steels is systematically studied, and the role of Mo in interphase precipitates and its coarsening behavior is revisited. It is found that (Ti, Mo)C precipitates instead of TiC are formed in the Mo-containing alloys, and the average site fraction of Mo in (Ti, Mo)C is almost independent of the bulk Mo content. Moreover, the number density of interphase precipitates can be substantially enhanced by a minor addition of Mo, albeit it does not further rise with increasing the bulk Mo content. This is because the Mo fraction in (Ti, Mo)C rather than the bulk Mo content governs the driving force for precipitation nucleation and the interfacial energy of the (Ti, Mo)C/α and (Ti, Mo)C/γ interfaces. In addition to the reduced interfacial energy, decrease of Ti trans-interface diffusivity has been identified as another key reason for the enhanced carbide coarsening resistance in Mo-containing alloys.","(Ti, Mo)C; Carbide nucleation; Coarsening resistance; Interfacial energy; Interphase precipitation; Trans-interface diffusivity","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-05-16","","","Novel Aerospace Materials","","",""
"uuid:c47c6b98-2be5-45e0-a22e-9f88cea73a7d","http://resolver.tudelft.nl/uuid:c47c6b98-2be5-45e0-a22e-9f88cea73a7d","Petri-net based cooperation modeling and time analysis of emergency response in the context of domino effect prevention in process industries","Zhou, Jianfeng (Guangdong University of Technology); Reniers, G.L.L.M.E. (TU Delft Safety and Security Science; Universiteit Antwerpen; Katholieke Universiteit Leuven)","","2022","Emergency response is an important way to reduce losses after a major industrial accident occurs and mitigation measures should be arranged and analyzed in preparedness. The cooperation in emergency response actions which make up an emergency response process has a significant impact on the efficiency and success rate (or reliability) of emergency response, and improper arrangement of actions may reduce emergency response efficiency. As emergency response is characterized by rapid response, this work studies the success of emergency response based on time analysis. In this paper, cooperation modes of emergency response actions and their time characteristics are analyzed. A timed colored Petri-net (TCPN) based approach is proposed to model the cooperation of the actions and perform time analysis. The proposed approach is illustrated by an example of fire brigades’ response to a tank fire. Simulations are performed and the probabilities of preventing fire escalation under different cooperation modes are analyzed. TCPN based modeling and analysis of emergency response actions are helpful for planning the necessary actions in the preparation of an emergency situation.","Cooperation modeling; Emergency response actions; Time analysis; Timed colored Petri-net","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Safety and Security Science","","",""
"uuid:881aceeb-6c6c-4d9a-916f-9a60db0196cf","http://resolver.tudelft.nl/uuid:881aceeb-6c6c-4d9a-916f-9a60db0196cf","Carbon-Iron Electron Transport Channels in Porphyrin–Graphene Complex for ppb-Level Room Temperature NO Gas Sensing","Gao, Yixun (South China Normal University); Wang, Jianqiang (South China Normal University); Feng, Yancong (South China Normal University); Cao, Nengjie (South China Normal University); Li, Hao (National Center for International Research on Green Optoelectronics; South China Normal University); de Rooij, Nicolaas Frans (South China Normal University); Umar, Ahmad (Najran University); French, P.J. (TU Delft Bio-Electronics); Wang, Yao (South China Normal University); Zhou, Guofu (South China Normal University)","","2022","It is a great challenge to develop efficient room-temperature sensing materials and sensors for nitric oxide (NO) gas, which is a biomarker molecule used in the monitoring of inflammatory respiratory diseases. Herein, Hemin (Fe (III)-protoporphyrin IX) is introduced into the nitrogen-doped reduced graphene oxide (N-rGO) to obtain a novel sensing material HNG-ethanol. Detailed XPS spectra and DFT calculations confirm the formation of carbon–iron bonds in HNG-ethanol during synthesis process, which act as electron transport channels from graphene to Hemin. Owing to this unique chemical structure, HNG-ethanol exhibits superior gas sensing properties toward NO gas (Ra/Rg = 3.05, 20 ppm) with a practical limit of detection (LOD) of 500 ppb and reliable repeatability (over 5 cycles). The HNG-ethanol sensor also possesses high selectivity against other exhaled gases, high humidity resistance, and stability (less than 3% decrease over 30 days). In addition, a deep understanding of the gas sensing mechanisms is proposed for the first time in this work, which is instructive to the community for fabricating sensing materials based on graphene-iron derivatives in the future.","carbon -iron bonds; gas sensors; graphene; Hemin; nitric oxide","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Bio-Electronics","","",""
"uuid:3e540878-2d5e-4f0a-b028-978cc958f967","http://resolver.tudelft.nl/uuid:3e540878-2d5e-4f0a-b028-978cc958f967","Coupled effects of corrosion damage and sustained loading on the flexural behavior of RC beams strengthened with CFRP anchorage system","Pan, Tanbo (Tongji University); Zheng, Yonglai (Tongji University); Zhou, Yujue (Tongji University; Sanming University); Liu, Yongcheng (Tongji University); Yu, Kunlong (Tongji University); Zhou, Y. (TU Delft Applied Mechanics)","","2022","This paper presents the results of an experimental study on the flexural behavior of carbon fibre reinforced polymer (CFRP) anchorage system strengthened reinforced concrete (RC) beams under the coupled effects of corrosion damage and sustained loading. The test beams were subjected to combined accelerated corrosion in 5% NaCl solution and sustained loads for 25, 50 and 100 days at 0% and 50% load levels of the virgin beam ultimate load capacity. The failure modes, load carrying capacity, deflection, ductility and strain response of the beams were investigated in detail. The results indicated that CFRP anchorage systems enhanced the yield and ultimate load of the corrosion-damaged beams. The use of CFRP anchorage system restored the ultimate load of corroded beams between 87.6% and 104.8% and the yield load between 81.9% and 92.7% with respect to those of the virgin beam. In contrast, the ductility and energy absorption index suffered a decline. CFRP-strengthened beams showed a reduction of 4.5%–28.9% for the ductility index compared with their counterparts without CFRP anchorage system. Sustained loads resulted in more considerable reductions in load-bearing capacity, greater loss of rebars mass, wider width of corrosion cracks, indicating a significant coupling effect between sustained loading and corrosion damage. Three typical failure modes of the CFRP-strengthened beams were observed and explained in the paper, thus revealing the failure mechanism of CFRP-strengthened beams. In the engineering practice of CFRP anchorage system, the coupled effects of corrosion damage and sustained loading on the strengthened systems should be taken into accountant comprehensively.","CFRP anchorage system; Corrosion; Flexural behavior; Reinforced concrete; Strengthening; Sustained loading","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Applied Mechanics","","",""
"uuid:1148f23f-7bbd-4a9d-9e9b-a4f72d908f43","http://resolver.tudelft.nl/uuid:1148f23f-7bbd-4a9d-9e9b-a4f72d908f43","Direct microbial electron uptake as a mechanism for stainless steel corrosion in aerobic environments","Zhou, Enze (Northeastern University); Li, Feng (Tianjin University); Zhang, Dawei (University of Science and Technology Beijing); Xu, Dake (Northeastern University); Li, Zhong (Northeastern University); Jia, Ru (Ohio University); Song, Hao (Tianjin University); Gu, Tingyue (Ohio University); Homborg, A.M. (Netherlands Defence Academy); Mol, J.M.C. (TU Delft Team Arjan Mol)","","2022","Shewanella oneidensis MR-1 is an attractive model microbe for elucidating the biofilm-metal interactions that contribute to the billions of dollars in corrosion damage to industrial applications each year. Multiple mechanisms for S. oneidensis-enhanced corrosion have been proposed, but none of these mechanisms have previously been rigorously investigated with methods that rule out alternative routes for electron transfer. We found that S. oneidensis grown under aerobic conditions formed thick biofilms (∼50 µm) on stainless steel coupons, accelerating corrosion over sterile controls. H2 and flavins were ruled out as intermediary electron carriers because stainless steel did not reduce riboflavin and previous studies have demonstrated stainless does not generate H2. Strain ∆mtrCBA, in which the genes for the most abundant porin-cytochrome conduit in S. oneidensis were deleted, corroded stainless steel substantially less than wild-type in aerobic cultures. Wild-type biofilms readily reduced nitrate with stainless steel as the sole electron donor under anaerobic conditions, but strain ∆mtrCBA did not. These results demonstrate that S. oneidensis can directly consume electrons from iron-containing metals and illustrate how direct metal-to-microbe electron transfer can be an important route for corrosion, even in aerobic environments.","Direct electron transfer; Microbiologically influenced corrosion; Porin-cytochrome conduit; Shewanella oneidensis; Stainless steel","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-11-05","","","Team Arjan Mol","","",""
"uuid:ca0d07cd-62bc-4859-b98e-d8c62683327c","http://resolver.tudelft.nl/uuid:ca0d07cd-62bc-4859-b98e-d8c62683327c","Left ventricular thrombus after acute ST-segment elevation myocardial infarction: Multi-parametric cardiac magnetic resonance imaging with long-term outcomes","Shi, Ruo yang (Shanghai Jiao Tong University); Chen, Bing hua (Shanghai Jiao Tong University); Wu, Chong wen (Shanghai Jiao Tong University); Wesemann, Luke (Wayne State University); Hu, Jiani (Wayne State University); Xu, Jian rong (Shanghai Jiao Tong University); Zhou, Yan (Shanghai Jiao Tong University); Tao, Q. (TU Delft ImPhys/Medical Imaging; Leiden University Medical Center); Wu, Lian ming (Shanghai Jiao Tong University)","","2022","Left ventricular thrombus (LVT) after acute ST-segment elevation myocardial infarction (STEMI) are generally associated with poorer outcomes for patients at long-term follow-up. We hypothesis that tissue characteristics and strain parameters by cardiac magnetic resonance (CMR) imaging may indicate the interactions of LVT with ventricular myocardium remodeling at both acute stage and chronic stages in STEMI patients. This retrospective study included 111 consecutive STEMI patients (38 with LVT and 73 without LVT). All patients underwent CMR during acute stage (within 7 days) and chronic stage (after at least 2 months) periods after percutaneous coronary intervention (PCI). Left ventricular native T1, extracellular volume (ECV), radial, circumferential, and longitudinal strain were analyzed in both phases. Major adverse cardiac events (MACE, including cardiovascular death, myocardial reinfarction, and hospitalization for heart failure), thromboembolic and bleeding events, were the clinical endpoints of the study. During the acute stage, left ventricular ejection fraction (LVEF) (OR 0.77, P value = 0.01) and longitudinal strain (OR 1.90, P value < 0.001) were correlated with LVT formation. Strain parameters were reduced, while the native T1 and ECV values of both the infarcted area and remote myocardium were elevated in LVT patients. During the chronic stage, LVT resolved in 29 of 38 patients (76%). LVT remaining patients had lower LVEF, a larger LV, and higher ECV in the acute stage than those of the LVT-resolved patients. In the long-term follow up of 678 days, LVT (HR 2.45, P value = 0.02), aneurysm (HR 1.81, P value = 0.04), and native T1 (HR 2.44, P value = 0.01) were identified as three independent predictors of MACE, the incidence of thromboembolic events and bleeding events by a multivariable stepwise Cox proportional hazards regression. STEMI patients developing LVT had worse LV function, myocardial infarction extent, strain, and higher T1 and ECV values than STEMI patients without LVT. The LVT-remaining patients in the chronic stage had poorer functional and mapping parameters beginning in the first week. During the acute stage, LVEF and global longitudinal strain were independent correlated with LVT formation. During the long-term follow up, LVT, aneurysm and elevated myocardial T1 were associated with adverse outcomes in acute STEMI patients.","Extracellular volume; Left ventricular thrombus; Strain analysis; T1 map","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","ImPhys/Medical Imaging","","",""
"uuid:ee504601-79bb-48ee-97bc-bb5d54374695","http://resolver.tudelft.nl/uuid:ee504601-79bb-48ee-97bc-bb5d54374695","Ammonium-assimilating microbiome: A halophilic biosystem rationally optimized by carbon to nitrogen ratios with stable nitrogen conversion and microbial structure","Zhang, Mengru (Shandong University); Han, Fei (Shandong University); Liu, Zhe (Shandong University); Han, Yufei (Shandong University); Li, L. (TU Delft Sanitary Engineering); Zhou, Weizhi (Shandong University)","","2022","The contradiction between theoretical metabolism of ammonium assimilation and experiential understanding of conventional biosystems makes the rational optimization of the ammonium-assimilating microbiome through carbon to nitrogen (C/N) ratios perplexing. The effect of different C/N ratios on ammonium-assimilating biosystems was investigated in saline wastewater treatment. C/N ratios significantly hindered the nutrient removal efficiency, but ammonium-assimilating biosystems maintained functional stability in nitrogen conversions and microbial communities. With sufficient biomass, higher than 86% ammonium and 73% phosphorus were removed when C/N ratios were higher than 25. Ammonium assimilation dominated the nitrogen metabolism in all biosystems even under relatively low C/N ratios, evidenced by the extremely low abundances of nitrification functional genes. Different C/N ratios did not significantly change the bacterial community structure of ammonium-assimilating biosystems. It is anticipated that the ammonium-assimilating biosystem with advantages of clear metabolic pathway and easy optimization can be applied to nutrient removal and recovery in saline environments.","Ammonium assimilation; Ammonium-assimilating biosystems; Bacterial community; C/N ratios; Saline wastewater treatment","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Sanitary Engineering","","",""
"uuid:d30f03ed-96e3-471e-a2c2-6e4da3a4cba9","http://resolver.tudelft.nl/uuid:d30f03ed-96e3-471e-a2c2-6e4da3a4cba9","Extrusion-based additive manufacturing of Mg-Zn/bioceramic composite scaffolds","Dong, J. (TU Delft Biomaterials & Tissue Biomechanics); Lin, P. (TU Delft Pavement Engineering); Putra, N.E. (TU Delft Biomaterials & Tissue Biomechanics); Tümer, N. (TU Delft Biomaterials & Tissue Biomechanics); Leeflang, M.A. (TU Delft Biomaterials & Tissue Biomechanics); Huan, Z. (Shanghai Institute of Ceramics Chinese Academy of Sciences); Fratila-Apachitei, E.L. (TU Delft Biomaterials & Tissue Biomechanics); Chang, J. (Shanghai Institute of Ceramics Chinese Academy of Sciences); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2022","The treatment of femoral nonunion with large segmental bone defect is still challenging. Although magnesium alloys have been considered potential materials for such a treatment, their application is limited by their fast degradation. Adding bioceramic particles into magnesium to form Mg-matrix composites is a promising strategy to adjust their biodegradation rates and to improve their mechanical properties and cytocompatibility further. Here, we developed an extrusion-based additive manufacturing technique to fabricate biodegradable Mg-Zn/bioceramic composite scaffolds ex-situ. Inks carrying a Mg-Zn powder and 5, 10 and 15% β-tricalcium phosphate (TCP) powder particles were investigated regarding the dispersion of β-TCP particles in the inks and viscoelastic properties. Optimally formulated inks were then employed for subsequent 3D printing of porous composite scaffolds. The in vitro biodegradation rate of the scaffolds containing 5% β-TCP decreased to 0.5 mm/y, which falls within the range desired for critical-sized bone substitution. As compared to the monolithic Mg-Zn scaffolds, the elastic moduli and yield strengths of the composite scaffolds were much enhanced, which remained in the range of the cancellous bone properties even after 28 d of in vitro degradation. The Mg-Zn/5TCP and Mg-Zn/10TCP scaffolds also exhibited improved biocompatibility when cultured with preosteoblasts, as compared to Mg-Zn scaffolds. In addition, the ALP activity and mineralization level of the composite scaffolds were much enhanced in the extracts of the composite scaffolds. Taken together, this research marks a great breakthrough in fabricating porous Mg-matrix composite scaffolds that meet several design criteria in terms of appropriate biodegradation rate, mechanical properties, and bioactivity. Statement of significance: The treatment of posttraumatic femoral nonunion with large segmental bone defect is still challenging. In this study, we developed a multi-material extrusion-based additive technique to fabricate porous Mg/bioceramic composite scaffolds for such a treatment. The technique allowed for the fine-tuning of printable inks to optimize the dispersion of micro-sized particles. The relative densities of the struts of the fabricated composite scaffolds reached 99%. The added bioceramic particles (β-TCP) exhibited proper interfacial bonding with the Mg alloy matrix. The porous Mg-based composite possessed desired biodegradability, bone-mimicking mechanical properties throughout the in vitro biodegradation period and improved bioactivity to bone cells. These results demonstrated great prospects of extrusion-based 3D printed porous Mg materials to be developed further as ideal biodegradable bone-substituting materials.","3D printing; Composite; Magnesium; Material extrusion; Scaffold","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:b2353f69-def7-43e7-af85-388564926577","http://resolver.tudelft.nl/uuid:b2353f69-def7-43e7-af85-388564926577","A numerical assessment on the managed aquifer recharge to achieve sustainable groundwater development in Chaobai River area, Beijing, China","Liu, S. (TU Delft Water Resources; IHE Delft Institute for Water Education); Zhou, Yangxiao (IHE Delft Institute for Water Education; Hebei University); Luo, Weijia (IHE Delft Institute for Water Education); Wang, Feiran (IHE Delft Institute for Water Education); McClain, M.E. (TU Delft Water Resources; IHE Delft Institute for Water Education); Wang, Xu sheng (China University of Geosciences)","","2022","Intensive groundwater exploitation has depleted groundwater storage and led to a series of geo-environmental problems in Beijing Plain, China. Managed Aquifer Recharge (MAR) has been endorsed to mitigate the groundwater storage depletion and achieve groundwater sustainability. A pilot MAR has been tested in the Chaobai River catchment since 2015. An innovative large-scale MAR consisting of 9 cascade terraced infiltration ponds was proposed and its effectiveness was assessed in this study using an integrated modelling approach. The integrated model coupled the regional and local transient flow and transport processes. The transient regional flow model simulated historical groundwater level declines and storage depletion in the Beijing Plain from 1995 to 2018. The coupled regional and local flow model was used to simulate the pilot MAR test in the Chaobai River from 2015 to 2018. A significant groundwater level increase was observed nearby the pilot MAR since 2015. The transport model results indicate that approximately 40% of the infiltrated water was captured by pumping wells in the No.8 well field. The models were further used to assess the long-term effects of the large-scale MAR from 2020 to 2050. The simulation results show that the groundwater system will reach a new equilibrium state under the implementation of the large-scale MAR scheme. Almost 91% of the abstracted water in the No. 8 well field will come from the MAR infiltration. The proposed large-scale MAR is very effective in restoring the depleted aquifer storage and maintaining the groundwater abstraction in the No.8 well field. However, with the increase of the groundwater level, the infiltration rate of several ponds will decrease. Therefore, it is important to maintain a dynamic balance between artificial recharge and groundwater abstraction in order to achieve a sustainable long-term MAR operation in the region.","Infiltration rate and capacity; Managed aquifer recharge; Restoration of groundwater storage; Simulation models; Sustainability of a large well field","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Water Resources","","",""
"uuid:19970bf0-78a9-46e3-9494-761ee9f432d7","http://resolver.tudelft.nl/uuid:19970bf0-78a9-46e3-9494-761ee9f432d7","The key factor in High Pressure Hydrogenotrophic Denitrification: Hydrogen partial pressure","Zhou, Jianmin (East China University of Science and Technology); Ding, Lei (East China University of Science and Technology); Shi, Mu (East China University of Science and Technology); Lindeboom, R.E.F. (TU Delft Sanitary Engineering); Cui, Changzheng (East China University of Science and Technology)","","2022","In the envisaged hydrogen economy, H2 could be an interesting alternative electron donor for the denitrification of drinking water or wastewater. The main obstacle to engineering the hydrogenotrophic denitrification process is the low solubility of H2 in water under atmospheric pressure, which limits denitrification rate and nitrogen removal efficiency. In this paper, we demonstrated a novel configuration of hydrogenotrophic denitrification, namely High Pressure Hydrogenotrophic Denitrification (HPHD). Elevated H2 partial pressure (pH2) was employed to increase dissolved H2 concentration and concomitantly enhance denitrification rate. Our results showed that the specific denitrification rate increased from 9.6 mg N/(gVSS·h) at 0.5 bars to 51.0 mg N/(gVSS·h) at 9 bars in HPHD. The denitrification effect could be retained with elevated pH2 at a low temperature. The specific denitrification rate at 3 bars and 15 °C was 20.5 mg N/(gVSS·h), approximately 1.5 times that at 1 bar and 30 °C, which was quite beneficial for hydrogenotrophic denitrification under cold conditions. Different from nitrite reduction, less impact was observed on nitrate reduction by low temperature, which explained high nitrite accumulation in HPHD at 15 °C. Overall, our investigations shed light on the role of pH2 in the promising solution for nitrogen removal in HPHD.","High pressure; Hydrogen; Low temperature; Nitrite accumulation; Specific denitrification rate","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Sanitary Engineering","","",""
"uuid:f59eb904-bdb1-4a59-920b-35d058a6ef18","http://resolver.tudelft.nl/uuid:f59eb904-bdb1-4a59-920b-35d058a6ef18","Solvent Engineering for High-Performance Two-Dimensional Ruddlesden-Popper CsPbI3Solar Cells","Chen, Haiqiang (Lanzhou University); Lei, Yutian (Lanzhou University); Yao, Huanhuan (Lanzhou University); Li, Zhizai (Lanzhou University); Peng, Guoqiang (Lanzhou University); Zhou, Xufeng (Liaocheng University); Wang, H. (TU Delft Photovoltaic Materials and Devices); Wang, Qian (Lanzhou University); Jin, Zhiwen (Lanzhou University)","","2022","Two-dimensional (2D) Ruddlesden-Popper (RP) CsPbI3 exhibits enhanced phase stability compared with 3D CsPbI3. However, the issue of the uncontrollable crystallization process limits its photovoltaic performance. Here, the influence of a binary mixed solvent on the film quality and photovoltaic properties of (PEA)2Cs4Pb5I16 (n = 5) is studied in detail. It is demonstrated that the crystallization rate and crystal growth can be controlled by adjusting the amount of dimethyl sulfoxide (DMSO). Optimizing the solvent composition with adding 10% DMSO in pure dimethyl formamide (DMF) leads to perfect coverage, larger flaky 2D grains, reduced grain boundaries, and a better vertical orientation to the substrate due to the formation of a more stable intermediate phase. This can form good interface contact, which is beneficial to charge transport/extraction between TiO2 (electron transport layer, ETL) and perovskite, finally resulting in improved device performance. The enhancement of the power conversion efficiency of the optimized device based on DMF/DMSO (9:1) is 3.57% compared with the reference device based on pure DMF. This work illustrates the role of crystallization kinetics in the RP CsPbI3 film and offers a simple and effective method for high-performance 2D CsPbI3 solar cells.","2D inorganic perovskites; crystallization kinetics; intermediate phase; Ruddlesden-Popper phase; solvent engineering","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-02-19","","","Photovoltaic Materials and Devices","","",""
"uuid:c5597a1e-37a0-485a-ae6c-b1e3ef8cd458","http://resolver.tudelft.nl/uuid:c5597a1e-37a0-485a-ae6c-b1e3ef8cd458","An inter-city energy migration framework for regional energy balance through daily commuting fuel-cell vehicles","He, Yingdong (Hunan University; University of California); Zhou, Yuekuan (The Hong Kong University of Science and Technology; HKUST Shenzhen-Hong Kong Collaborative Innovation Research Institute); Liu, Jia (Guangzhou University; The Hong Kong Polytechnic University); Liu, Zhengxuan (TU Delft Design & Construction Management; Hunan University); Zhang, Guoqiang (Hunan University)","","2022","Spatiotemporal energy interaction and sharing are promising solutions to penetrate renewable energy, enhance grid power stability, and improve regional energy flexibility. However, the current literature is restrained in a small-scale neighborhood level, without considering inter-city energy migration through spatiotemporal complementarity between renewable-abundant regions (like suburb or countryside areas) and demand-shortage regions (like city centers). In this study, the energy interaction boundary is extended from a neighborhood scale to an inter-city scale, to maximize the renewable energy penetration, demand coverage, and reduce regional energy imbalance. This study firstly proposes a holistic framework on inter-city transportation-based energy migration, consisting of a residential community with rooftop photovoltaic systems and electrical batteries, an office building, hydrogen vehicles (HVs), a hydrogen (H2) station, and local power grids, for the energy transmission between building groups in spatially different regions through the daily commuting of HVs. Optimal grid-regulation strategies are thereafter proposed and adopted to stabilize the grid power and reduce energy costs. Parametric analysis on energy trading strategies and prices has been conducted, to improve the participation motivations of different stakeholders. Results indicate that, compared to the reference case with isolated buildings and vehicles, the transportation-based energy migration framework covers 23.2 % of the office energy demand and elevates the community's renewable self-use ratio from 72.7 % to 98.6 %. Meanwhile, the maximum grid-export power in the renewable-abundant region (suburb residential community) and the annual grid-import power in the demand-shortage region (city-center office) are reduced by up to 86.9 % (from 155.7 to 20.4 kW) and 29.4 % (from 49.0 to 34.6 kW), respectively. Moreover, even considering the fuel cell degradation cost of HVs, the transportation-based energy migration framework reduces the operating costs of the office building and HVs (the H2 cost and the fuel cell degradation cost) by 16.4 % (from $52791.3 to $44154.7) and 1.7 % (from $27172.5 to $26707.4), respectively. Afterward, compared to the reference case, the peak-shaving and load-shaping grid-regulation strategies can decrease the peak grid-export power of the community by about 71.6 % (from 155.7 to 44.2 kW), and the maximum grid-import power of the office by 23.7 % (from 49.0 to 37.4 kW), respectively. Furthermore, the transportation-based energy migration framework is economically feasible, only when the renewable export price for H2 production is 0.07 $/kWh, the onsite-renewable-generated H2 lower than 6.5 $/kg for the HV owners, and the vehicle-to-building electricity lower than 0.3 $/kWh for the office building. This study provides a novel inter-city energy migration framework with hydrogen networks to enhance district energy sharing, improve regional energy balance and reduce carbon emission, together with frontier guidelines on energy trading prices to promote participation motivations from different stakeholders.","Distributed hydrogen infrastructure; Energy trading; Hydrogen economy; Innovative Grid-regulation strategy; Spatiotemporal energy sharing network; Transportation-based Inter-city energy migration","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-01-31","","","Design & Construction Management","","",""
"uuid:679aca4d-8276-4480-ace5-4a1736cbd8fd","http://resolver.tudelft.nl/uuid:679aca4d-8276-4480-ace5-4a1736cbd8fd","Artificial intelligence powered large-scale renewable integrations in multi-energy systems for carbon neutrality transition: Challenges and future perspectives","Liu, Zhengxuan (TU Delft Design & Construction Management; Hunan University); Sun, Ying (Concordia University); Xing, Chaojie (Hunan University); Liu, Jia (Guangzhou University; The Hong Kong Polytechnic University); He, Yingdong (Hunan University); Zhou, Yuekuan (The Hong Kong University of Science and Technology; HKUST Shenzhen-Hong Kong Collaborative Innovation Research Institute); Zhang, Guoqiang (Hunan University)","","2022","The vigorous expansion of renewable energy as a substitute for fossil energy is the predominant route of action to achieve worldwide carbon neutrality. However, clean energy supplies in multi-energy building districts are still at the preliminary stages for energy paradigm transitions. In particular, technologies and methodologies for large-scale renewable energy integrations are still not sufficiently sophisticated, in terms of intelligent control management. Artificial intelligent (AI) techniques powered renewable energy systems can learn from bio-inspired lessons and provide power systems with intelligence. However, there are few in-depth dissections and deliberations on the roles of AI techniques for large-scale integrations of renewable energy and decarbonisation in multi-energy systems. This study summarizes the commonly used AI-related approaches and discusses their functional advantages when being applied in various renewable energy sectors, as well as their functional contribution to optimizing the operational control modalities of renewable energy and improving the overall operational effectiveness. This study also presents practical applications of various AI techniques in large-scale renewable energy integration systems, and analyzes their effectiveness through theoretical explanations and diverse case studies. In addition, this study introduces limitations and challenges associated with the large-scale renewable energy integrations for carbon neutrality transition using relevant AI techniques, and proposes further promising research perspectives and recommendations. This comprehensive review ignites advanced AI techniques for large-scale renewable integrations and provides valuable informational instructions and guidelines to different stakeholders (e.g., engineers, designers and scientists) for carbon neutrality transition.","Artificial intelligent techniques; Carbon neutrality; Energy transition; Large-scale integration; Renewable energy","en","review","","","","","","","","","","","Design & Construction Management","","",""
"uuid:83312bef-f1fc-4660-990e-c8632742ee2a","http://resolver.tudelft.nl/uuid:83312bef-f1fc-4660-990e-c8632742ee2a","Examining industrial air pollution embodied in trade: implications of a hypothetical China-UK FTA","Zhang, Yuquan W. (Shanghai Jiao Tong University); Geng, Yong (Shanghai Jiao Tong University; Tongji University); Zhang, Bin (Ministry of Ecology and Environment); Yang, Shaohua (Shanghai Jiao Tong University); Izikowitz, David V. (Shanghai Jiao Tong University); Yin, Haitao; Wu, F. (TU Delft Energie and Industrie; ETH Zürich); Yu, Haishan (Shanghai Jiao Tong University); Liu, Huiwen (Shanghai Jiao Tong University); Zhou, Weiduo (Shanghai Academy of Social Sciences)","","2022","Very few developed economies have a full free trade agreement (FTA) with China. This study employs one GTAP model and builds an extended environmental multi-region input–output model to investigate a hypothetical China-UK FTA, concerning embodied industrial emissions of SO2, PM2.5, NOX, and NH3. The economic sectors are also classified based on their embodied pollution intensity and trade advantage index under various FTA scenarios. Results show that the UK’s GDP and welfare and China’s welfare will increase, along with changes in their trade structures. Overall, this FTA brings about larger net impacts on embodied emissions of SO2 than on PM2.5, NOX and NH3, and both countries are net importers of the latter three pollutants. Key sectors such as non-metallic mineral products, chemical products, and agriculture are inclined to become less competitive and less polluting under the FTA. The inclusion of agri-food sectors exhibits slight counteracting effects in general. The findings are of policy importance as they provide insights into how best to target key sectors, seeking a balance between trade development and environmental protection.","Embodied pollution; Environmental MRIO; FTA; GTAP; Trade competitiveness","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Energie and Industrie","","",""
"uuid:2b161ba2-3f05-4d33-9418-6a41668344ef","http://resolver.tudelft.nl/uuid:2b161ba2-3f05-4d33-9418-6a41668344ef","Fractal characteristics and damage evaluation of corroded beams under four-point bending tests based on acoustic emission techniques","Zheng, Yonglai (Tongji University); Wen, Yuan (Tongji University); Pan, Tanbo (Tongji University); Liu, Yongcheng (Tongji University); Zhou, Yujue (Tongji University; Sanming University); Li, Ruizhi (Tongji University); Zhou, Y. (TU Delft Concrete Structures)","","2022","This study investigated the relationship between the acoustic emission (AE) signals parameter sequence fractal characteristics and the damage evolution information of corroded reinforced concrete (RC) beams under four-point bending. Strength deterioration behavior and AE data can be obtained by coupling the four-point bending test and the AE monitoring. The results show that AE ringing counts of corroded and uncorroded beams had prominent fractal characteristics. The fractal dimension values of corroded RC beams all showed a fluctuating rise to a peak and then a sharp drop before the failure. The damage index corresponding to the peak point decreases with the increase of corrosion degree. Fractal dimension peak point could be used as an early warning point for corroded RC beams' failure. Moreover, the AE fractal dimension analysis can effectively reflect the pattern of crack development, which have an important value for evaluating the process of corroded RC beams rupture.","Acoustic emission; Concrete fracture monitoring; Damage assessment; Fractal Characteristics; Steel corrosion","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Concrete Structures","","",""
"uuid:72ef293a-5e1b-478a-932c-ac7b900b669c","http://resolver.tudelft.nl/uuid:72ef293a-5e1b-478a-932c-ac7b900b669c","Sparse Bayesian deep learning for dynamic system identification","Zhou, H. (TU Delft Robot Dynamics); Chahine, I. (Student TU Delft); Zheng, Wei Xing (Western Sydney University); Pan, W. (TU Delft Robot Dynamics; The University of Manchester)","","2022","This paper proposes a sparse Bayesian treatment of deep neural networks (DNNs) for system identification. Although DNNs show impressive approximation ability in various fields, several challenges still exist for system identification problems. First, DNNs are known to be too complex that they can easily overfit the training data. Second, the selection of the input regressors for system identification is nontrivial. Third, uncertainty quantification of the model parameters and predictions are necessary. The proposed Bayesian approach offers a principled way to alleviate the above challenges by marginal likelihood/model evidence approximation and structured group sparsity-inducing priors construction. The identification algorithm is derived as an iterative regularised optimisation procedure that can be solved as efficiently as training typical DNNs. Remarkably, an efficient and recursive Hessian calculation method for each layer of DNNs is developed, turning the intractable training/optimisation process into a tractable one. Furthermore, a practical calculation approach based on the Monte-Carlo integration method is derived to quantify the uncertainty of the parameters and predictions. The effectiveness of the proposed Bayesian approach is demonstrated on several linear and nonlinear system identification benchmarks by achieving good and competitive simulation accuracy. The code to reproduce the experimental results is open-sourced and available online.","Deep neural networks; Group sparsity; Regularised system identification; Sparse Bayesian learning","en","journal article","","","","","","","","","","","Robot Dynamics","","",""
"uuid:f168c729-222d-49c4-906c-514e401f71fa","http://resolver.tudelft.nl/uuid:f168c729-222d-49c4-906c-514e401f71fa","Dynamic analysis of fire induced domino effects to optimize emergency response policies in the chemical and process industry","Zhou, Jianfeng (Guangdong University of Technology); Reniers, G.L.L.M.E. (TU Delft Safety and Security Science; Universiteit Antwerpen; Katholieke Universiteit Leuven)","","2022","A fire accident is one the most dangerous accidents that may lead to knock-on effects, especially in the plants dealing with large quantities of hazardous substances. Different from other accidents, e.g., explosions, fires can last certain period of time and the thermal radiations emitted by them have a synergistic effect. At the same time, the heat-up of target installations under the effect of thermal radiation is also a process that takes a certain amount of time. These characteristics make fire induced domino effects a dynamic process. During an emergency response due to a fire accident, emergency personnel may arrive at the fire scene at different times, so they may face different accident situations. In this work, an adaptive timed Petri-net (ATPN) based approach is proposed to model the propagation of fires and perform a dynamic analysis of potential domino effects. The definition of ATPN as well as the enabling and execution rules is provided. Through simulations, not only the probabilities of fires in different installations, but also the probabilities of the fire extension propagated over time can be obtained. An example of a tank farm fire illustrates the approach. Our developed approach for carrying out a dynamic analysis of domino effects is helpful for emergency preparation.","Domino effect; Emergency response; Fire accident; Petri-net; Time analysis","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Safety and Security Science","","",""
"uuid:5d055e62-5c7b-4b42-970b-ac878fb12706","http://resolver.tudelft.nl/uuid:5d055e62-5c7b-4b42-970b-ac878fb12706","Resilience assessment of asphalt pavement rutting under climate change","Zhang, Chao (Harbin Institute of Technology); Tan, Yiqiu (Harbin Institute of Technology); Gao, Y. (TU Delft Pavement Engineering); Fu, Yongkang (Poly Changda Overseas Engineering Co.); Li, Jilu (Harbin Institute of Technology); Li, Shuai (Harbin Institute of Technology); Zhou, Xingye (Ministry of Transport of the People's Republic of China)","","2022","The service performances of asphalt pavement, especially rutting, will be inevitably affected by climate change. However, existing studies have generally focused on the rutting depth and rutting life, and thus became insufficient for comprehensively evaluating the influence of climate change on rutting over the service life. A resilience assessment method for asphalt pavement rutting is developed to solve the above problem. First, the original resilience method is extended to fit the system whose performance level continues to decline. Then, the calculation formulas of rutting resilience are derived by combining the rutting prediction model and the level assessment model. Subsequently, the influence degrees of climate change in representative cities on rutting resilience are studied. The results suggest that neglecting climate change in rutting design of asphalt pavement will lead to insufficient resilience, especially in northern China. Furthermore, the predicted temperature under RCP8.5 should be employed for asphalt pavement design.","Asphalt pavement; Climate change; Recovery stage; Resilience; Resistance stage; Rutting","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Pavement Engineering","","",""
"uuid:0040a274-8455-4bb0-bfdd-f0376c79d959","http://resolver.tudelft.nl/uuid:0040a274-8455-4bb0-bfdd-f0376c79d959","Direct Injection of Aluminum-Organic Matter Flocs to Reduce Soil Permeability and Create a Vertical Flow Barrier in Situ","Zhou, Jianchao (TU Delft Geo-engineering); Laumann, S.J. (TU Delft Applied Geophysics and Petrophysics); Heimovaara, T.J. (TU Delft Geoscience and Engineering)","","2022","This study presents a novel geotechnical engineering approach that utilizes naturally occurring processes to reduce soil permeability in-situ. This approach is inspired by a soil stratification process (Podzolization), where a low permeability layer is formed by metal-organic matter precipitates. In a field experiment, a direct aluminum-organic matter (Al-OM) floc injection was applied to create a continuous vertical flow barrier in a dike. Direct injection uses the shear-dependent size of Al-OM flocs. High-shear conditions (i.e., during injection) lead to the breakage of Al-OM flocs and thus allow their transportation in soils. When the injection stops and low-shear conditions prevail, the Al-OM flocs re-grow in size and block the pores, which ultimately reduces soil permeability. Two different Al-OM floc concentrations were applied in the field. Results show that a continuous flow barrier is only formed at lower concentrations; at higher concentrations a scattered permeability reduction was achieved. This demonstrates the viability of this approach in reducing soil permeability in-situ and shows that the spatial distribution of the flocs depends on input concentration.","","en","journal article","","","","","","","","","","Geoscience and Engineering","Applied Geophysics and Petrophysics","","",""
"uuid:a8e3a4dd-5d7f-4be6-b6e1-bfca9d3d0851","http://resolver.tudelft.nl/uuid:a8e3a4dd-5d7f-4be6-b6e1-bfca9d3d0851","Induced seismicity red-light thresholds for enhanced geothermal prospects in the Netherlands","Schultz, Ryan (Stanford University); Muntendam-Bos, A.G. (TU Delft Applied Geology; Staatstoezicht op de Mijnen); Zhou, W. (TU Delft Applied Geology); Beroza, Gregory C. (Stanford University); Ellsworth, William L. (Stanford University)","","2022","Prospects for geothermal energy in the Netherlands have renewed concerns around induced earthquakes. Risks from induced earthquakes are managed by traffic light protocols (TLPs), where the red-light is chosen as the stop-point before exceeding a tolerance to risk. Here, we simulate post-shut-in earthquake scenarios based on realistic information for the Netherlands. We focus on three risk metrics: aggregates like nuisance and damage impacts and also local personal risk (LPR) – a likelihood of building collapse fatality for an individual. Our results show that the severity of these risks varies spatially by orders of magnitude. Prior induced seismicity (e.g., the 2012 Huizinge event) provides a reference baseline to calibrate the Dutch earthquake risk tolerances. We find that these calibrated risk tolerances are similar to those observed in North America, suggesting an underlying sociological ‘license to operate.’ Furthermore, the use of calibrated risk tolerances results in nuisance concerns completely eclipsing the other two metrics. We compare our results to a hypothetical Groningen geothermal operation and find that our approach sets red-light thresholds approximately one magnitude unit below the ML 3.6 Huizinge event. Overall, our results provide a first-order recommendation for red-light thresholds and proactive management of Dutch enhanced geothermal induced seismicity.","Enhanced geothermal systems; Induced seismicity; Red-light; Seismic hazard; Seismic risk; Traffic light protocols","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Applied Geology","","",""
"uuid:a6fec65d-b5ff-4a56-adca-431b4af37adb","http://resolver.tudelft.nl/uuid:a6fec65d-b5ff-4a56-adca-431b4af37adb","DEM-based stress transmission in asphalt mixture skeleton filling system","Xing, Chao (Harbin Institute of Technology); Liu, Bo (Harbin Institute of Technology); Sun, Zhiqi (Shijiazhuang Tiedao University); Tan, Yiqiu (Harbin Institute of Technology); Liu, X. (TU Delft Pavement Engineering); Zhou, Changhong (Guilin University of Electronic Technology)","","2022","Asphalt mixture is a skeleton filling system consisting of aggregate, asphalt, and mineral powder. High performance asphalt mixture design is directly affected by internal stress transmission of skeleton filling system. In this paper, the discrete element method based on digital image was employed to study the stress transmission. By analyzing the effect of skeleton structure on the contact force between aggregate and mortar, it is concluded that the skeleton aggregate in the asphalt mixture is the main stress transmission medium. The lower the degree of disruption, the higher the contact force of skeleton aggregate. At the same time, the variation coefficient of contact force of asphalt mortar with low filling coefficient is larger and the localization phenomenon is more serious. By analyzing the effect of mortar properties on the contact force between aggregate and mortar, it is concluded that the lower the modulus of asphalt mortar, the higher the degree of localization of contact force and the more likely to have local damage.","Asphalt mixtures; Contact force transmission; DEM; Mesostructure; Skeleton filling system","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Pavement Engineering","","",""
"uuid:5d62b73f-d4d4-4e0b-8450-9e76e06af08e","http://resolver.tudelft.nl/uuid:5d62b73f-d4d4-4e0b-8450-9e76e06af08e","Aerodynamic design and evaluation of a ducted fan lift system for vertical takeoff and landing flying cars","Jiang, Hanjie (Universiti Sains Malaysia); Zhou, Y. (TU Delft Control & Simulation; Universiti Sains Malaysia); Ho, H.W. (TU Delft Control & Simulation; Universiti Sains Malaysia)","","2022","Urban air mobility is a relatively new concept that has been proposed in recent years as a means of transporting passengers and goods in urban areas. It encompasses a diverse range of Vertical TakeOff and Landing (VTOL) vehicles that function more like passenger-carrying drones for on-demand transportation. Among them, the car-like VTOL is advantageous due to its compact configuration, safe rotors, high user affinity, and technological fashion. These characteristics are frequently derived from the flying car’s Ducted Fan Lift System (DFLS). This study aims to develop a method for the rapid design and the evaluation of the aerodynamic performance of the DFLS, to support the preliminary scheme demonstration of the ducted fan flying car. The proposed method uses blade element theory to design the unducted fan and applies momentum theory to calculate the aerodynamic thrust of the DFLS. The DFLS of a 1:3 scale verifier for a flying car scheme was designed and evaluated using the proposed method and a numerical method, respectively. To validate the proposed method, a prototype of the scale DFLS was manufactured and tested, and the result was compared with those of the proposed theoretical method and the numerical method. This study demonstrates that while both the theoretical and numerical methods are capable of designing an unducted fan accurately, the theoretical method is simpler and faster. Compared to the DFLS test results, the theoretical method’s average difference is approximately 1.9%. When evaluating the DFLS, the accuracy of the numerical calculation is reduced, and the difference is greater than 30% at low power. The theoretical method presented in this paper can be used to improve the aerodynamic design and evaluation efficiency of the DFLS and to aid in the configuration evaluation of VTOLs equipped with ducted fans.","Ducted fan design; flying car; numerical calculation; urban air mobility; vertical takeoff and landing","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Control & Simulation","","",""
"uuid:0797bee5-0a87-4784-84d0-335d6604b4c2","http://resolver.tudelft.nl/uuid:0797bee5-0a87-4784-84d0-335d6604b4c2","Online robot guidance and navigation in non-stationary environment with hybrid Hierarchical Reinforcement Learning","Zhou, Y. (TU Delft Control & Simulation; Universiti Sains Malaysia); Ho, H.W. (TU Delft Control & Simulation; Universiti Sains Malaysia)","","2022","Hierarchical Reinforcement Learning (HRL) provides an option to solve complex guidance and navigation problems with high-dimensional spaces, multiple objectives, and a large number of states and actions. The current HRL methods often use the same or similar reinforcement learning methods within one application so that multiple objectives can be easily combined. Since there is not a single learning method that can benefit all targets, hybrid Hierarchical Reinforcement Learning (hHRL) was proposed to use various methods to optimize the learning with different types of information and objectives in one application. The previous hHRL method, however, requires manual task-specific designs, which involves engineers’ preferences and may impede its transfer learning ability. This paper, therefore, proposes a systematic online guidance and navigation method under the framework of hHRL, which generalizes training samples with a function approximator, decomposes the state space automatically, and thus does not require task-specific designs. The simulation results indicate that the proposed method is superior to the previous hHRL method, which requires manual decomposition, in terms of the convergence rate and the learnt policy. It is also shown that this method is generally applicable to non-stationary environments changing over episodes and over time without the loss of efficiency even with noisy state information.","Function approximation; Hybrid Hierarchical Reinforcement Learning; Non-stationary environment; Online guidance and navigation; State space decomposition","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Control & Simulation","","",""
"uuid:c7311211-3010-4ded-9607-621575b5ff08","http://resolver.tudelft.nl/uuid:c7311211-3010-4ded-9607-621575b5ff08","Monitoring the Monthly Expansion Pattern of Pioneer Vegetation in Tidal Flats Using a Terrestrial Laser Scanner","Zhan, Y.J. (TU Delft Coastal Engineering; Shanghai Estuarine and Coastal Science Research Center); Aarninkhof, S.G.J. (TU Delft Hydraulic Engineering); Wang, Zhengbing (TU Delft Coastal Engineering); Zhou, Yunxuan (Shanghai Estuarine and Coastal Science Research Center)","","2022","Research on the expansion pattern of pioneer vegetation in tidal flats is important, because this pattern affects the development of both topography and ecology. This study aimed to determine the monthly expansion patterns of seedlings and tussocks by using terrestrial laser scanning (TLS). Overall change process research and spatial analyses of both seedling recruitment and tussock development were carried out in this work. The results show that the overall change in pioneer vegetation reflected an expansion toward the shoreline in the first year and then a northward colonization in the second year. Moreover, positive feedback effects were observed between vegetation colonization and sedimentation accretion. Colonization accelerated the depositional process at the study site. Moreover, sedimentation accretion in the northern subarea, which is located close to the seawall, promoted the colonization of vegetation in this region. A strong spatial relationship was observed between seedling recruitment and tussock development. Tussocks tended to force seedlings to expand outward by squeezing the established space of the seedlings. Moreover, seedlings were densely concentrated within a certain distance from tussocks. The distances between seedlings and tussocks tended to shorten annually as the entire vegetation area underwent the expansion process. The average distance between seedlings was found to be concentrated from 10 to 20 m. The monthly vegetation expansion process was studied on small and medium scales in this work, revealing the advantages of TLS technology in rapidly acquiring data with high resolution and high precision.","Monthly monitoring; seedling and tussock","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","Hydraulic Engineering","Coastal Engineering","","",""
"uuid:c3c3354e-c548-43da-86f0-63fb55a7c18f","http://resolver.tudelft.nl/uuid:c3c3354e-c548-43da-86f0-63fb55a7c18f","Advances on methane reforming in solid oxide fuel cells","Fan, Liyuan (James Cook University, Australia); Li, Chao'en (CSIRO Energy); van Biert, L. (TU Delft Ship Design, Production and Operations); Zhou, Shou Han (James Cook University, Australia); Tabish, Asif Nadeem (University of Engineering and Technology Lahore); Mokhov, Anatoli (Rijksuniversiteit Groningen); Aravind, Purushothaman Vellayani (Rijksuniversiteit Groningen); Cai, Weiwei (China University of Geosciences, Wuhan)","","2022","With the demand for anticipated green hydrogen and power production, novel and upgraded catalytic processes are desired for more effective utilization of precious natural resources. Methane steam reforming is an advanced and matured technology for converting methane to hydrogen and syngas. As a renewable energy resource containing a large amount of methane, biogas is a promising fuel for green hydrogen production. Because of the fuel flexibility and high efficiency relative to alternative technologies, solid oxide fuel cells with internal methane reforming capabilities may become an economically viable technology for hydrogen and power generation. A renewed interest in the flexible application of biogas in solid oxide fuel cells for the co-generation of green hydrogen and power has emerged recently, driven by the spectacular advances in fuel cell technology. However, the methane reforming process suffers from inaccurate or unprecise descriptions. Knowledge of the factors influencing the reforming reaction rate on the novel and improved reforming anode catalysts in solid oxide fuel cells are still required to design and operate such systems. Therefore, a comprehensive review of recent advances in methane steam reforming provides meaningful insight into technological progress. Herein, major descriptors of the methane steam reforming reaction engineering are reviewed to provide a practical perspective for the direct application of biogas in solid oxide fuel cells, which serves as an alternative sustainable, flexible process for green hydrogen and power co-production. Current advances and challenges are evaluated, and perspectives for future work are discussed.","Biogas; Hydrogen production; Methane reforming kinetics; Solid oxide fuel cells; System modelling","en","review","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Ship Design, Production and Operations","","",""
"uuid:dc53d6f3-fee3-4f92-aa77-23d1ca3c99f3","http://resolver.tudelft.nl/uuid:dc53d6f3-fee3-4f92-aa77-23d1ca3c99f3","Micro-nano bubbles assisted laccase for biocatalytic degradation of bisphenols","Zhang, Jie (Chongqing Technology and Business University); Tan, Lirong (Chongqing Technology and Business University); Hagedoorn, P.L. (TU Delft BT/Biocatalysis); Wang, Ruiqi (Chongqing Technology and Business University); Wen, Li (Chongqing Technology and Business University); Wu, Siwei (Chongqing Technology and Business University); Tan, Xuemei (Chongqing Technology and Business University); Xu, Hui (Chongqing Technology and Business University); Zhou, Xing (Chongqing Academy of Chinese Materia Medica, Chongqing)","","2022","Bisphenols are important industrial materials for example for the production of plastics, but are also well known for their adverse health effects, in particular bisphenol A (BPA) is an endocrine disruptor. The widespread use of plastics has raised concerns. Therefore, the removal of bisphenols from wastewater has sparked the interest of the scientific community. This work introduces a novel hybrid technique of micro-nano bubbles assisted laccase (MNB-Lac) to degrade bisphenols in water. The feasibility of MNB-Lac using BPA as a model contaminant was evaluated by comparing with MNB, Lac, ultrasound (UL), UL-Lac, and UL-MNB-Lac. Comprehensive investigations were carried out to understand the specific influences of key process parameters including the initial pollutant concentration, temperature, air intake, pH, outlet pipe length, and Lac concentration on BPA degradation. The alkaline environment and extended length of outlet pipe could improve the degradation efficiency further. MNB-Lac exhibited 2.3–6.2 folds higher BPA degradation and less time than the other above process under the optimal parameters. The mechanism of MNB-Lac revealed that the generation of hydroxyl radical, high O2 solubility, and high mass transfer efficiency induced by MNB play important roles on enhancing the degradation catalyzed by Lac. MNB-Lac was successfully used for treating bisphenol B, bisphenol C, and the mixture of three bisphenols with high removal efficiency. Subsequently, these degradation products were analyzed by GC–MS. MNB-Lac potentially represents an innovative technology with considerable advantages in contaminant cleanup and time efficiency for treating phenolic contaminated water. Furthermore, the findings provide new insights into the enhancement of the performance of an oxidizing enzyme by introducing MNB technology.","Bisphenol; Degradation; Hydroxyl radical; Laccase; Micro-nano bubbles","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","BT/Biocatalysis","","",""
"uuid:f0090251-0935-4a8c-bec8-5cacb424aec6","http://resolver.tudelft.nl/uuid:f0090251-0935-4a8c-bec8-5cacb424aec6","Machine Learning-Assisted probabilistic fatigue evaluation of Rib-to-Deck joints in orthotropic steel decks","Heng, J. (TU Delft Steel & Composite Structures; Shenzhen University); Zheng, Kaifeng (Southwest Jiaotong University); Feng, Xiaoyang (Southwest Jiaotong University); Veljkovic, M. (TU Delft Steel & Composite Structures); Zhou, Zhixiang (Shenzhen University)","","2022","This study integrates the fatigue test and numerical prediction to derive a comprehensive probability-stress-life (P-S-N) curve for rib-to-deck (RD) welded joints in orthotropic steel decks. Fatigue tests of RD joints are conducted to measure fatigue strength and crack growth data. Based on the test, a probabilistic fatigue crack growth (PFCG) model is established to predict the distribution of fatigue life under various stress ranges. Two machine learning tools are adopted to assist the PFCG model-based prediction, i.e., the Gaussian process regression (GPR) and dynamic Bayesian network (DBN). The GPR is used to train a surrogate model solving stress intensity factors for the PFCG prediction, using 2,000 samples generated from finite element (FE) analyses. The trained model is then validated by a new dataset of 100 FE samples. An adapted DBN model is proposed to update the PFCG model with the fatigue crack growth data measured from ten specimens. According to the result, the application of GPR can reduce the solution cost of the PFCG prediction by approximately 1,875 times. Compared with the prior PFCG model, the updated posterior model shows an improved agreement with the test data, i.e., the maximum difference in fatigue strength between model prediction and test data decreases from 12% to 3%. Based on the posterior PFCG model, the P-S-N curve of RD joints is statistically derived using sufficient numerical samples.","dynamic Bayesian network; Gaussian process regression; Orthotropic steel decks; Probabilistic fatigue assessment; Rib-to-deck joints","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-12-09","","","Steel & Composite Structures","","",""
"uuid:33d48b63-f465-4beb-a279-9a1b7aa0dca5","http://resolver.tudelft.nl/uuid:33d48b63-f465-4beb-a279-9a1b7aa0dca5","Thermodynamics up to the melting point in a TaVCrW high entropy alloy: Systematic ab initio study aided by machine learning potentials","Zhou, Ying (Loughborough University); Srinivasan, Prashanth (University of Stuttgart); Körmann, F.H.W. (TU Delft Team Marcel Sluiter; Max-Planck-Institut für Eisenforschung); Grabowski, Blazej (University of Stuttgart); Smith, Roger (Loughborough University); Goddard, Pooja (Loughborough University); Duff, Andrew Ian (STFC Daresbury Laboratory)","","2022","Multi-principal-component alloys have attracted great interest as a novel paradigm in alloy design, with often unique properties and a vast compositional space auspicious for materials discovery. High entropy alloys (HEAs) belong to this class and are being investigated for prospective nuclear applications with reported superior mechanical properties including high-temperature strength and stability compared to conventional alloys. Computational materials design has the potential to play a key role in screening such alloys, yet for high-temperature properties, challenges remain in finding an appropriate balance between accuracy and computational cost. Here we develop an approach based on density-functional theory (DFT) and thermodynamic integration aided by machine learning based interatomic potential models to address this challenge. We systematically evaluate and compare the efficiency of computing the full free energy surface and thermodynamic properties up to the melting point at different stages of the thermodynamic integration scheme. Our new approach provides a ×4 speed-up with respect to comparable free energy approaches at the level of DFT, with errors on high-temperature free energy predictions less than 1 meV/atom. Calculations are performed on an equiatomic HEA, TaVCrW - a low-activation composition and therefore of potential interest for next generation fission and fusion reactors.","","en","journal article","","","","","","","","","","","Team Marcel Sluiter","","",""
"uuid:c2d15bc9-93ab-4978-9d1c-76441302c247","http://resolver.tudelft.nl/uuid:c2d15bc9-93ab-4978-9d1c-76441302c247","Guanidium-assisted crystallization engineering for highly efficient CsPbI3 solar cells","Wang, Shuo (Lanzhou University); Xu, Youkui (Lanzhou University); Wang, Qian (Lanzhou University); Zhou, Xufeng (Liaocheng University); Li, ZhenHua (Lanzhou University); Wang, Meng (Lanzhou University); Lei, Yutian (Lanzhou University); Zhang, Hong (Lanzhou University); Wang, H. (TU Delft Photovoltaic Materials and Devices); Jin, Zhiwen (Lanzhou University)","","2022","Iodine vacancies and uncoordinated iodide ions of CsPbI3 films are mainly responsible for nonradiative recombination. Here, we report a composition-engineering passivation method that through guanidium (GA+) and I− forms strong hydrogen bonds to passivate iodine vacancies and reduce defects. Both experimental and theoretical results confirmed strong chemical interactions between GA+ and uncoordinated I− in the GAxCs1−xPbI3 bulk or at the grain boundary. Moreover, GA+ doping could slow down the crystallization speed of perovskite films during the deposition process. As a result, we observed GA+ modified films with much lower defect density, larger grain size, and better carrier extraction and transportation. Upon GA+ passivation, the power conversion efficiency (PCE) is boosted from 18.01% to 19.05%, with open-circuit voltage (VOC) enhancement from 1.08 V to 1.14 V.","","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-10-25","","","Photovoltaic Materials and Devices","","",""
"uuid:6e27a89b-6031-40be-8535-61bd5d4dbcf9","http://resolver.tudelft.nl/uuid:6e27a89b-6031-40be-8535-61bd5d4dbcf9","HRBF-Fusion: Accurate 3D Reconstruction from RGB-D Data Using On-the-fly Implicits","Xu, Yabin (Nanjing University of Aeronautics and Astronautics); Nan, L. (TU Delft Urban Data Science); Zhou, Laishui (Nanjing University of Aeronautics and Astronautics); Wang, Jun (Nanjing University of Aeronautics and Astronautics); Wang, C.C. (TU Delft Materials and Manufacturing; The University of Manchester)","","2022","Reconstruction of high-fidelity 3D objects or scenes is a fundamental research problem. Recent advances in RGB-D fusion have demonstrated the potential of producing 3D models from consumer-level RGB-D cameras. However, due to the discrete nature and limited resolution of their surface representations (e.g., point or voxel based), existing approaches suffer from the accumulation of errors in camera tracking and distortion in the reconstruction, which leads to an unsatisfactory 3D reconstruction. In this article, we present a method using on-the-fly implicits of Hermite Radial Basis Functions (HRBFs) as a continuous surface representation for camera tracking in an existing RGB-D fusion framework. Furthermore, curvature estimation and confidence evaluation are coherently derived from the inherent surface properties of the on-the-fly HRBF implicits, which are devoted to a data fusion with better quality. We argue that our continuous but on-the-fly surface representation can effectively mitigate the impact of noise with its robustness and constrain the reconstruction with inherent surface smoothness when being compared with discrete representations. Experimental results on various real-world and synthetic datasets demonstrate that our HRBF-fusion outperforms the state-of-the-art approaches in terms of tracking robustness and reconstruction accuracy.","3D reconstruction; camera tracking; closed-form HRBFs; fusion; registration","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright older of this work and the author uses the Dutch legislation to make this work public.","","2022-10-28","","","Urban Data Science","","",""
"uuid:f52b5741-4598-4c5e-a551-2caf12aafd8c","http://resolver.tudelft.nl/uuid:f52b5741-4598-4c5e-a551-2caf12aafd8c","Quantification and Assessment of Global Terrestrial Water Storage Deficit Caused by Drought Using GRACE Satellite Data","Lu, Jing (Chinese Academy of Sciences); Jia, Li (Chinese Academy of Sciences); Zhou, Jie (Central China Normal University); Jiang, Min (Chinese Academy of Sciences); Zhong, Yulong (China University of Geosciences, Wuhan); Menenti, M. (TU Delft Optical and Laser Remote Sensing; Chinese Academy of Sciences)","","2022","A drought-induced water storage deficit index (D-WSDI) is proposed to quantify the response of GRACE-based terrestrial water storage change to meteorological drought and the impact of drought on water storage deficit. D-WSDI is defined as the normalized residual component of GRACE time-series data after removing the long-term trend and seasonal components. The evaluation based on the Emergency Events Database (EM-DAT) showed that more than 90% of global drought events from 2002 to 2019 led to a water storage deficit, which can be detected by the proposed D-WSDI. The severity of the water storage deficit caused by drought increases with the extending drought duration. An average of 73% of water storage deficit months at the global scale is related to precipitation shortages. The cumulative precipitation deficit in relatively short periods of less than 9 months can lead to the water storage deficit in low-latitude regions, whereas a longer time scale is required to lead to a water storage deficit in high-latitude regions. The negative monthly precipitation anomaly of about -20% can lead to a water storage deficit in high rainfall regions, whereas the negative precipitation anomaly can reach -80% in arid and semiarid areas. D-WSDI holds the capability to quantify the water storage deficit caused by drought, especially in the regions with terrestrial water storage change influenced by the long-term trends in climate and anthropogenic activities, and can be used as an index of drought monitoring with similar or superior performance compared to some traditional drought indices.","Decomposing time series; drought; Gravity Recovery and Climate Experiment (GRACE); water storage deficit","en","journal article","","","","","","","","","","","Optical and Laser Remote Sensing","","",""
"uuid:b744923a-1aa8-4826-9e88-220324010e0a","http://resolver.tudelft.nl/uuid:b744923a-1aa8-4826-9e88-220324010e0a","Functionalized Hydrogels for Articular Cartilage Tissue Engineering","Zhou, Liangbin (Chinese University of Hong Kong); Guo, Peng (Chinese University of Hong Kong; AO Research Institute Davos, Davos); D'Este, Matteo (AO Research Institute Davos, Davos); Tong, Wenxue (Chinese University of Hong Kong); Xu, Jiankun (Chinese University of Hong Kong); Yao, Hao (Chinese University of Hong Kong); Stoddart, Martin J. (AO Research Institute Davos, Davos); van Osch, G.J.V.M. (TU Delft Biomaterials & Tissue Biomechanics; Erasmus MC); Ho, Kevin Ki Wai (Chinese University of Hong Kong); Li, Zhen (AO Research Institute Davos, Davos); Qin, Ling (Chinese Academy of Sciences; Chinese University of Hong Kong)","","2022","Articular cartilage (AC) is an avascular and flexible connective tissue located on the bone surface in the diarthrodial joints. AC defects are common in the knees of young and physically active individuals. Because of the lack of suitable tissue-engineered artificial matrices, current therapies for AC defects, especially full-thickness AC defects and osteochondral interfaces, fail to replace or regenerate damaged cartilage adequately. With rapid research and development advancements in AC tissue engineering (ACTE), functionalized hydrogels have emerged as promising cartilage matrix substitutes because of their favorable biomechanical properties, water content, swelling ability, cytocompatibility, biodegradability, and lubricating behaviors. They can be rationally designed and conveniently tuned to simulate the extracellular matrix of cartilage. This article briefly introduces the composition, structure, and function of AC and its defects, followed by a comprehensive review of the exquisite (bio)design and (bio)fabrication of functionalized hydrogels for AC repair. Finally, we summarize the challenges encountered in functionalized hydrogel-based strategies for ACTE both in vivo and in vitro and the future directions for clinical translation.","Articular cartilage; Cartilage repair; Cartilage tissue engineering; Clinical translation; Functionalized hydrogels","en","review","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:90f46102-35bf-4cdd-9f9e-0582f94f04ea","http://resolver.tudelft.nl/uuid:90f46102-35bf-4cdd-9f9e-0582f94f04ea","An improved mean-field homogenization model for the three-dimensional elastic properties of masonry","Zhou, Y. (TU Delft Concrete Structures); Sluys, Lambertus J.; Esposito, R. (TU Delft Materials- Mechanics- Management & Design)","","2022","Accurate assessment of the overall mechanical behavior of masonry, composed of bricks and mortar joints, remains challenging due to its inhomogeneous and orthotropic nature. In this study, the feasibility of various mean-field homogenization schemes for the three-dimensional orthotropic elastic properties of masonry is comprehensively investigated. Three kinds of masonry patterns are considered, including the stack bonded pattern, the running bonded pattern and the double-leaf Flemish bonded pattern that has received limited attention so far. Special attention is paid to the homogenization schemes which have not been applied to the masonry case, such as Lielens’ interpolative double inclusions (D-I) and the interaction direct derivative (IDD) schemes. After a comparison between the well-known mean-field homogenization schemes, an improved micro-mechanical model is proposed by combining the advantages of the IDD and D-I models. The validation of the proposed model is conducted through a comparison against experimental data from literature and numerical results obtained via finite element analyses (FEA). The results show that the proposed model can accurately evaluate the orthotropic elastic properties of the three masonry typologies for a wide range of stiffness ratios between brick and mortar, ranging from 1 to 1000. The proposed model also shows better performance than the classical schemes especially when the stiffness ratios between brick and mortar are higher than 10, which is of major importance for the application of mean-field homogenization based multiscale methods to the nonlinear analysis of masonry. Furthermore, the presented homogenization method can be of interest for other anisotropic materials, e.g., laminate materials.","Masonry; Mean-field homogenization; Micromechanics; Orthotropic stiffness tensor","en","journal article","","","","","","","","","","Materials- Mechanics- Management & Design","Concrete Structures","","",""
"uuid:9bd871d0-b176-47ea-a91f-9d3c698ac103","http://resolver.tudelft.nl/uuid:9bd871d0-b176-47ea-a91f-9d3c698ac103","The Guidance and Control of Urban Planning for Reuse of Industrial Heritage: A Study of Nanjing","Wu, Y. (TU Delft Heritage & Technology; Southeast University); Pottgiesser, U. (TU Delft Heritage & Technology; Hagschule Ostwestfalen-Lippe); Quist, W.J. (TU Delft Heritage & Technology); Zhou, Qi (Southeast University)","","2022","Industrial heritage is among the products of modern urban development, and the influencing factors of its regeneration and development are often complex. Due to different national conditions, the research progress and approaches in industrial heritage reuse in China are different from other countries. While industrial heritage sites in Europe have become part of urban redevelopment in several regions, China still focuses mostly on single objects, lacking systematic analysis, especially at the urban scale. Regarding the city of Nanjing, an operational approach to complex urban dynamics is proposed based on a simplified analysis of official statistics, maps and GIS technology. The influence mechanisms of Nanjing’s urban planning on industrial heritage regeneration and development after 1990 are analyzed. The results show that urban growth boundaries, traffic accessibility, eco-environmental policies, population distribution, industrial renovation investment and natural resource change all have a significant impact on the abandonment and regeneration of Nanjing industrial heritage. This study expands the research perspective of industrial heritage reuse in China and proposes a clearer systematic planning strategy for the future of industrial heritage in cities.","urban development; mechanism of influence; industrial heritage; reuse","en","journal article","","","","","","","","","","","Heritage & Technology","","",""
"uuid:32257460-42c8-4f3b-8874-9de931e7351b","http://resolver.tudelft.nl/uuid:32257460-42c8-4f3b-8874-9de931e7351b","Resource Allocation Equity in the China’s Rural Three-Tier Healthcare System","Ao, Yibin (Chengdu University of Technology); Feng, Qiqi (Chengdu University of Technology); Zhou, Zhongli (Chengdu University of Technology); Chen, Yunfeng (Purdue University); Wang, T. (TU Delft Design & Construction Management)","","2022","The rural three-tier healthcare system is an essential part of the Chinese healthcare service system. To ensure rural residents’ equal access to such healthcare services, it is necessary to examine the current status of the healthcare system in rural China and formulate corresponding improvement suggestions. This study therefore collects the data from the China Health Statistics Yearbook, the China Health Yearbook and the China Statistical Yearbook between the years 2004 and 2021 to calculate the Gini coefficient (G), health resource density index (HRDI) and Theil index (T) first, and then perform the Mann–Kendall test afterwards to evaluate the equity of healthcare resource allocation comprehensively. This series of analysis helps in drawing the following conclusions: (1) county and county-level city medical and health institutions (CMHIs) show a higher development trend in comparison with township hospitals (THs) and village clinics (VCs); (2) VCs have higher institutional fairness, while for beds and personnel, CMHIs and THs are more fairly positioned; (3) more specifically for CMHIs and THs, personnel allocation is more fair than beds and institution allocations; (4) the density of healthcare resources in the eastern and central regions is higher than that in the western part, while the intra-regional distribution of beds and personnel in the west and central regions is better than that in the eastern region; (5) intra-regional differences are more significant than inter-regional differences and the fairness according to population distribution is higher than that of geographical area allocation. The results of this study provide theoretical basis for further optimizing the allocation of healthcare resources and improving the fairness of healthcare resources allocation from a macro perspective.","equity; resource allocation; rural China; three-tier healthcare system","en","journal article","","","","","","","","","","","Design & Construction Management","","",""
"uuid:e6340faf-fb36-4812-bde9-345489f6e941","http://resolver.tudelft.nl/uuid:e6340faf-fb36-4812-bde9-345489f6e941","Deep learning for the rare-event rational design of 3D printed multi-material mechanical metamaterials","Pahlavani, H. (TU Delft Biomaterials & Tissue Biomechanics); Amani, M. (TU Delft Biomaterials & Tissue Biomechanics); Cruz Saldivar, M. (TU Delft Biomaterials & Tissue Biomechanics); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Mirzaali, Mohammad J. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2022","Emerging multi-material 3D printing techniques enables the rational design of metamaterials with not only complex geometries but also arbitrary distributions of multiple materials within those geometries, yielding unique combinations of elastic properties. However, discovering the rare designs that lead to highly unusual combinations of material properties, such as double-auxeticity and high elastic moduli, remains a non-trivial crucial task. Here, we use computational models and deep learning algorithms to identify rare-event designs. In particular, we study the relationship between random distributions of hard and soft phases in three types of planar lattices and the resulting mechanical properties of the two-dimensional networks. By creating a mapping from the space of design parameters to the space of mechanical properties, we are able to reduce the computational time required for evaluating each design to ≈2.4 × 10−6 s, and to make the process of evaluating different designs highly parallelizable. We then select ten designs to be 3D printed, mechanically test them, and characterize their behavior using digital image correlation to validate the accuracy of our computational models. Our simulation results show that our deep learning-based algorithms can accurately predict the mechanical behavior of the different designs and that our modeling results match experimental observations.","","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:0628d7d6-3580-4d46-9590-e031ac7f83f3","http://resolver.tudelft.nl/uuid:0628d7d6-3580-4d46-9590-e031ac7f83f3","A PDE-free, neural network-based eddy viscosity model coupled with RANS equations","Xu, R. (TU Delft Aerodynamics); Zhou, Xu Hui (Virginia Tech); Han, Jiequn (Flatiron Institute); Dwight, R.P. (TU Delft Aerodynamics); Xiao, Heng (Virginia Tech)","","2022","In fluid dynamics, constitutive models are often used to describe the unresolved turbulence and to close the Reynolds averaged Navier–Stokes (RANS) equations. Traditional PDE-based constitutive models are usually too rigid to calibrate with a large set of high-fidelity data. Moreover, commonly used turbulence models are based on the weak equilibrium assumption, which cannot adequately capture the nonlocal physics of turbulence. In this work, we propose using a vector-cloud neural network (VCNN) to learn the nonlocal constitutive model, which maps a regional mean flow field to the local turbulence quantities without solving the transport PDEs. The network is strictly invariant to coordinate translation, rotation, and uniform motion, as well as ordering of the input points. The VCNN-based nonlocal constitutive model is trained and evaluated on flows over a family of parameterized periodic hills. Numerical results demonstrate its predictive capability on target turbulence quantities of turbulent kinetic energy k and dissipation ɛ. More importantly, we investigate the robustness and stability of the method by coupling the trained model back to RANS solver. The solver shows good convergence with the simulated velocity field comparable to that based on k–ɛ model when starting from a reasonable initial condition. This study, as a proof of concept, highlights the feasibility of using a nonlocal, frame-independent, neural network-based constitutive model to close the RANS equations, paving the way for the further emulation of the Reynolds stress transport models.","Machine learning; Neural networks; Nonlocal model; RANS; Turbulence modelling","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Aerodynamics","","",""
"uuid:448b28ec-e2c4-4613-8aa1-6b6b3f55dcf9","http://resolver.tudelft.nl/uuid:448b28ec-e2c4-4613-8aa1-6b6b3f55dcf9","Monitoring Yearly Change Patterns of the Surface Tidal Trail (STT) in Tidal Flats: A Novel Morphological Indicator Extracted from a Near-Infrared Terrestrial Laser Scanner","Zhan, Y.J. (TU Delft Coastal Engineering; Shanghai Estuarine and Coastal Science Research Center); Aarninkhof, S.G.J. (TU Delft Hydraulic Engineering); Wang, Zhengbing (TU Delft Coastal Engineering); Zhou, Yunxuan (Shanghai Estuarine and Coastal Science Research Center)","","2022","Tidal flats play an important role in the geomorphological and biological dynamics of coasts. Research on the morphological evolution of tidal flats constitutes one of the key research issues pertaining to the sustainability of coastal ecosystems and related coastal defense issues. In this work, a novel indicator, the surface tidal trail (STT), was extracted from a near infrared terrestrial laser scanner and studied. The results show that the area intensity and size of STTs decline yearly. Meanwhile, the position shift of the peak value on the STT curves presents a similar pattern of hydrodynamic force in response to the seawall, which has been studied in previous works. Although no direct correlation between the STT intensity and the deposition rate was found, the corresponding hydrodynamic force data were not available in this work. The change process of STTs still provides a possible speculation that hydrodynamic force and the softness of tidal surfaces are two main factors that form and influence STTs. For future research, establishing the direct quantitative relationships among hydrodynamic force, topography, and STTs on different temporal and spatial scales would help to better understand this novel indicator.","fine-scale; micro topography; Seawall; surface moisture","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","Hydraulic Engineering","Coastal Engineering","","",""
"uuid:99dc4a89-524a-4740-95f0-bf3af94012a9","http://resolver.tudelft.nl/uuid:99dc4a89-524a-4740-95f0-bf3af94012a9","An Interface Co-modification Strategy for Improving the Efficiency and Stability of CsPbI3Perovskite Solar Cells","Guan, Hui (Lanzhou University); Lei, Yutian (Lanzhou University); Wu, Qiyuan (Lanzhou University); Zhou, Xufeng (Liaocheng University); Wang, H. (TU Delft Photovoltaic Materials and Devices); Wang, Gang (Ningbo University); Li, Wenquan (Qinghai Normal University); Jin, Zhiwen (Lanzhou University); Lan, Wei (Lanzhou University)","","2022","Interface engineering is a simple and effective strategy for improving the photovoltaic performance and stability of perovskite solar cells (PSCs). Herein, an interface co-modification strategy is proposed, using [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and 2-fluoro-1,4-phenylenediammonium iodide (2FPPD) to modify the electron transport layer (ETL)/perovskite (PVK) and the PVK/hole transport layer (HTL) interfaces, respectively. A series of characterizations demonstrate that the PCBM&2FPPD interface co-modification strategy effectively enhances the extraction and transport efficiency of carriers at the interface, passivates surface defects, inhibits the nonradiative recombination of carriers, and simultaneously inhibits ion migration. Moreover, this strategy improves the crystallinity and surface hydrophobicity of PVK and optimizes the energy level alignment of PSCs. As a result, all photovoltaic parameters are improved after optimization, where the power conversion efficiency (PCE) of PSCs has increased from 17.01% to 18.36%. Meanwhile, the optimized PSCs show excellent environmental stability, which can be stably stored in air (RH = 10-20%) for about 800 h.","CsPbI; defect passivation; interface engineering; perovskite solar cell; photovoltaic performance; stability","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-04-27","","","Photovoltaic Materials and Devices","","",""
"uuid:dfb87d95-4f18-4ce2-b2ca-be55b5c7f5b5","http://resolver.tudelft.nl/uuid:dfb87d95-4f18-4ce2-b2ca-be55b5c7f5b5","Anisotropic dislocation-domain wall interactions in ferroelectrics","Zhuo, Fangping (Technische Universität Darmstadt); Zhou, Xiandong (Technische Universität Darmstadt); Gao, Shuang (Technische Universität Darmstadt; Southwest Jiaotong University); Höfling, Marion (Technical University of Denmark); Braga Groszewicz, P. (TU Delft RST/Storage of Electrochemical Energy); Fulanović, Lovro (Technische Universität Darmstadt); Tan, Xiaoli (Iowa State University); Koruza, Jurij (Graz University of Technology); Damjanovic, Dragan (Swiss Federal Institute of Technology); Rödel, Jürgen (Technische Universität Darmstadt)","","2022","Dislocations are usually expected to degrade electrical, thermal and optical functionality and to tune mechanical properties of materials. Here, we demonstrate a general framework for the control of dislocation–domain wall interactions in ferroics, employing an imprinted dislocation network. Anisotropic dielectric and electromechanical properties are engineered in barium titanate crystals via well-controlled line-plane relationships, culminating in extraordinary and stable large-signal dielectric permittivity (≈23100) and piezoelectric coefficient (≈2470 pm V–1). In contrast, a related increase in properties utilizing point-plane relation prompts a dramatic cyclic degradation. Observed dielectric and piezoelectric properties are rationalized using transmission electron microscopy and time- and cycle-dependent nuclear magnetic resonance paired with X-ray diffraction. Succinct mechanistic understanding is provided by phase-field simulations and driving force calculations of the described dislocation–domain wall interactions. Our 1D-2D defect approach offers a fertile ground for tailoring functionality in a wide range of functional material systems.","","en","journal article","","","","","","","","","","","RST/Storage of Electrochemical Energy","","",""
"uuid:2b193530-7219-447c-8ca5-668b6bf69083","http://resolver.tudelft.nl/uuid:2b193530-7219-447c-8ca5-668b6bf69083","Seismic velocity changes in the Groningen reservoir associated with distant drilling","Zhou, W. (TU Delft Applied Geology; Universiteit Utrecht); Paulssen, Hanneke (Universiteit Utrecht)","","2022","In this study, we show that passively recorded data of nearby passing trains by a deep borehole geophone array could be linked to fluctuations of the gas-water contact in the Groningen reservoir in The Netherlands. During a period of 1.5 months, changes of inter-geophone P-wave travel times were detected by deconvolution interferometry of the recorded train signals. P-to-S converted waves, obtained by deconvolution of the horizontal component by the vertical component at individual geophones, showed simultaneous variations. The observed travel-time changes could be related to fluctuations of the gas-water contact in the observation well caused by pressure variations at a well drilling 4.5 km away. The ∼ 3.5 day delay between drilling in the reservoir and the seismic response yields a hydraulic diffusivity of approximately 5 m2/s and suggests that the pressure front is effectively propagated over such a long distance. Our observations illustrate that downhole geophone arrays can be used to monitor changes in the subsurface if repeating noise sources are available, and that unexpected effects may occur due to drilling.","","en","journal article","","","","","","","","","","","Applied Geology","","",""
"uuid:344797c6-a7ae-47a5-a4a8-b069f299cc75","http://resolver.tudelft.nl/uuid:344797c6-a7ae-47a5-a4a8-b069f299cc75","Lanthanide-Doped Nanoprobes as Orthogonal NIR-II Fluorescence Channels for In Vivo Information Storage","Wang, Xiaolu (Capital Normal University); Jia, Q. (TU Delft BT/Biocatalysis; Beijing Normal University); Ma, Liyi (Capital Normal University); Zhai, Xuejiao (Capital Normal University); Liu, Yuxin (Capital Normal University; Max-Planck-Inst. F. Kolloid-und G.); Liao, Xianquan (Capital Normal University); Zhou, Jing (Capital Normal University)","","2022","Information storage in vivo will lead to next-generation identification and security authentication. Here, an information storage method was proposed for in vivo application by using a pair of lanthanide-doped nanoprobes (NdNPs and ErNPs) with orthogonal emissions in the second near-infrared window. The information is stored in different fluorescence channels separately, while the selective readout could be realized by simply manipulating excitation wavelengths. The small-animal experiments primarily confirm the applicability of this method in vivo. The binary numbers ″1″ and ″0″ are implanted under the mice's skin, and the corresponding signals ″on″ and ″off″ can be collected by charge-coupled devices under different laser filter combinations. The design of lanthanide-doped probes with the nanoscale features and orthogonal emissions is expected to provide a new strategy for information storage in vivo. The lanthanide materials with excellent down-conversion near-infrared fluorescence performance have shown great application potential in the field of photonics.","information storage; multichannel imaging; orthogonal; rare earth-based nanoparticles; second near-infrared window","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","BT/Biocatalysis","","",""
"uuid:c75f864b-814f-4f8d-b749-0b503906af15","http://resolver.tudelft.nl/uuid:c75f864b-814f-4f8d-b749-0b503906af15","Quantifying the Uncertainty of Short-Term Vegetation Anomalies Detection Using Eo-Based Coarse-Resolution Vegetation Products","Zhou, J. (TU Delft Optical and Laser Remote Sensing; Central China Normal University; Key Laboratory for Geographical Process Analysis & Simulation of Hubei Province, Wuhan); Liu, Xuan (Central China Normal University; Key Laboratory for Geographical Process Analysis & Simulation of Hubei Province, Wuhan); Xiong, Xuqian (Central China Normal University; Key Laboratory for Geographical Process Analysis & Simulation of Hubei Province, Wuhan); Jia, Li (Chinese Academy of Sciences); Lu, Jing (Chinese Academy of Sciences); Cui, Yilin (Central China Normal University; Key Laboratory for Geographical Process Analysis & Simulation of Hubei Province, Wuhan)","","2022","Satellite-based Earth Observation systems archived a variety of vegetation products during the last 50 years, which can reveal regional to global ecosystem dynamics across diverse spatiotemporal scales. The anomaly metrics such as Vegetation Condition Index (VCI) defined by comparing the current vegetation growth condition to historical average status based on long-term EO-based vegetation products were widely used to delineate abnormal vegetation variation exerted by either climatic or anthropogenic factors (e.g., droughts, wildfires). However, currently available long-term vegetation products may differ from each other in terms of sensors (observational platform or spectral bands), bio-physical definitions (e.g., NDVI, EVI, LAI, and VOD), spatiotemporal resolution, as well as the time-spans, which results in inconsistency across these vegetation products. Taking the VCI as an example, this study evaluated the uncertainty of vegetation anomalies detected based on different vegetation products over the middle reach of the Yangtze River by explicitly considering the effect of sensors, biophysical definitions, and time-spans. The preliminary results showed that VCI derived from NDVI products from different sensors (AVHRR vs. MODIS) induced significant inconsistent anomalies over most landscapes. The differences resulting from products with different biophysical definitions (NDVI vs. EVI, LAI, and VOD) are much lower than those from different sensors but still significant over specific areas. As for the time-spans, the 20-year NDVI based VCI presented a considerable reduction in variance over the study area on average compared to VCI calculated based on 5-year NDVI. In summary, caution should be taken when applying EO-based vegetation products for vegetation anomalies mapping, especially for quantitative assessment.","EO-based vegetation products; uncertainty; vegetation anomalies; Vegetation Condition Index","en","conference paper","Institute of Electrical and Electronics Engineers (IEEE)","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Optical and Laser Remote Sensing","","",""
"uuid:6a7e0774-322a-42f6-af25-73cd221106a0","http://resolver.tudelft.nl/uuid:6a7e0774-322a-42f6-af25-73cd221106a0","Response of hydrogeological processes in a regional groundwater system to environmental changes: A modeling study of Yinchuan Basin, China","Li, J. (Chang'an University); Zhou, Yangxiao (Hebei University of Geosciences; IHE Delft Institute for Water Education); Wang, Wenke (Chang'an University); Liu, S. (TU Delft Water Resources; IHE Delft Institute for Water Education); Li, Ying (Geological Bureau of Ningxia Hui Autonomous Region, Yinchuan); Wu, Ping (Institute of Hydrogeology and Environmental Geology of Ningxia, Yinchuan)","","2022","The sustainable development of groundwater resources in arid and semi-arid regions is a challenging task hindered by climate change and human activities. The rational utilization and management of groundwater resources is, therefore, dependent on an understanding of the influences of human and climatic factors on the spatial distribution of groundwater resources and their change over time. The thick Quaternary aquifers in the Yinchuan Basin, China were used herein as an example of how to quantitatively assess spatial and temporal trends in groundwater resources in response to human activities and climate change. A 3D transient groundwater flow model was constructed and used to simulate the evolution and spatial variability of hydrogeological processes from 1990 to 2020. By subsequently applying regime shift detection and correlation analysis to the simulation results, we found that: 1) groundwater storage was continuously depleted over the 30-year period, reaching a cumulative depletion of 1.89×109 m3; 2) human activities were mainly responsible for variations in regional hydrogeological processes for a period of up to 30 years. Climate only affected short-term interannual fluctuations in groundwater storage; 3) human activities (e.g., river water diversion and groundwater abstractions) were the decisive factors causing a continuous reduction of groundwater resources. A policy-driven reduction in water diversion from the Yellow River directly led to a significant drop in groundwater storage, which had a consequent effect on surface water and groundwater interactions and altered agricultural irrigation patterns (crop patterns and irrigation methods); 4) the amount of groundwater recharge from the Yellow River and local lakes increased from 1990 to 2020, whereas the discharge of groundwater to the Yellow River and lakes decreased.","Climate change; Human activities; Numerical groundwater flow model; Quaternary sediments, Yinchuan Basin; Surface water-groundwater interactions","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Water Resources","","",""
"uuid:667d438c-de8e-411b-84b6-7d9102118bb6","http://resolver.tudelft.nl/uuid:667d438c-de8e-411b-84b6-7d9102118bb6","Electrical characteristics and photodetection mechanism of TiO2/AlGaN/GaN heterostructure-based ultraviolet detectors with a Schottky junction","Zhan, Teng (Chinese Academy of Sciences; University of Chinese Academy of Sciences); Sun, J. (TU Delft Electronic Components, Technology and Materials; Tsinghua University); Feng, Tao (Chinese Academy of Sciences; University of Chinese Academy of Sciences); Zhang, Yulong (Tsinghua University); Zhou, Binru (Chinese Academy of Sciences; University of Chinese Academy of Sciences); Zhang, Banghong (Chinese Academy of Sciences; University of Chinese Academy of Sciences); Wang, Junxi (Chinese Academy of Sciences; University of Chinese Academy of Sciences); Sarro, Pasqualina M (TU Delft Electronic Components, Technology and Materials); Zhang, Kouchi (TU Delft Electronic Components, Technology and Materials)","","2022","Recent research focusing on wide-bandgap and two-dimensional materials with a Schottky junction has provided a new concept for ultraviolet photodetectors. However, the working mechanism of the Schottky junction-based detector varies depending on the photosensitive materials used and the device structure. We demonstrated a TiO2/AlGaN/GaN heterostructure-based photodetector with a Schottky junction, integrating an ultraviolet photosensitive TiO2 nanolayer, a two-dimensional electron gas (2DEG) field effect transistor, and a metal-semiconductor Schottky diode. The spectral response wavelength region of the detector is 200-365 nm and the peak responsivity is 37.396 A W−1 at −5 V bias under 240 nm UV illumination, respectively. Meanwhile, a peak photo-to-dark current ratio (PDCR) of 5.1 × 102 at −2 V bias voltage was observed under 274 nm UV irradiation. This Schottky-based 2DEG heterostructure detector can realize three dominant working principles: (i) the Schottky emission mechanism at a low reverse voltage (0-1 V) before the current is fully turned on, (ii) the Poole-Frenkel emission mechanism at a medium reverse voltage (−1 to −2 V) with peak PDCR, and (iii) the Fowler-Nordheim tunneling mechanism at a high reverse voltage (>−2 V) with a high responsivity. Continuous cycle response measurement results indicate that the detectors have good response repeatability and reliability. The characteristics of response wavelength, responsivity, and stability show that the detector can be used for several commercial applications, including sunscreen UV monitoring and LED sterilization light source detection.","","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public. Correction: https://doi.org/10.1039/D2TC04491A","","2023-06-19","","","Electronic Components, Technology and Materials","","",""
"uuid:128aaec4-78e9-44cf-a33d-4b7ad2c03e22","http://resolver.tudelft.nl/uuid:128aaec4-78e9-44cf-a33d-4b7ad2c03e22","Seismic Noise Interferometry and Distributed Acoustic Sensing (DAS): Inverting for the Firn Layer S-Velocity Structure on Rutford Ice Stream, Antarctica","Zhou, W. (TU Delft Applied Geophysics and Petrophysics; University of Bristol); Butcher, Antony (University of Bristol); Brisbourne, Alex M. (British Antarctic Survey); Kufner, Sofia Katerina (British Antarctic Survey; Karlsruhe Institut für Technologie); Kendall, J. Michael (University of Oxford); Stork, Anna L. (Silixa)","","2022","Firn densification profiles are an important parameter for ice-sheet mass balance and palaeoclimate studies. One conventional method of investigating firn profiles is using seismic refraction surveys, but these are difficult to upscale to large-area measurements. Distributed acoustic sensing (DAS) presents an opportunity for large-scale seismic measurements of firn with dense spatial sampling and easy deployment, especially when seismic noise is used. We study the feasibility of seismic noise interferometry (SI) on DAS data for characterizing the firn layer at the Rutford Ice Stream, West Antarctica. Dominant seismic energy appears to come from anthropogenic noise and shear-margin crevasses. The DAS cross-correlation interferometry yields noisy Rayleigh wave signals. To overcome this, we present two strategies for cross-correlations: (a) hybrid instruments—correlating a geophone with DAS, and (b) stacking of selected cross-correlation panels picked in the tau-p domain. These approaches are validated with results derived from an active survey. Using the retrieved Rayleigh wave dispersion curve, we inverted for a high-resolution 1D S-wave velocity profile down to a depth of 100 m. The profile shows a “kink” (velocity gradient inflection) at ∼12 m depth, resulting from a change of compaction mechanism. A triangular DAS array is used to investigate directional variation in velocity, which shows no evident variations thus suggesting a lack of azimuthal anisotropy in the firn. Our results demonstrate the potential of using DAS and SI to image the near-surface and present a new approach to derive S-velocity profiles from surface wave inversion in firn studies.","distributed acoustic sensing; firn; glacier; near-surface imaging; noise interferometry; S-velocity model","en","journal article","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:53553f0e-2e2e-492e-8a17-a4837053fa56","http://resolver.tudelft.nl/uuid:53553f0e-2e2e-492e-8a17-a4837053fa56","Probing Spin Dynamics on Diamond Surfaces Using a Single Quantum Sensor","Dwyer, Bo L. (Harvard University); Rodgers, Lila V.H. (Princeton University); Urbach, Elana K. (Harvard University); Bluvstein, Dolev (Harvard University); Sangtawesin, Sorawis (Suranaree University of Technology, Nakhonratchasima); Zhou, Hengyun (Harvard University); Nassab, Yahia (Princeton University); Fitzpatrick, Mattias (Princeton University); Dobrovitski, V.V. (TU Delft QID/Dobrovitski Group; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft)","","2022","Understanding the dynamics of a quantum bit's environment is essential for the realization of practical systems for quantum information processing and metrology. We use single nitrogen-vacancy (NV) centers in diamond to study the dynamics of a disordered spin ensemble at the diamond surface. Specifically, we reduce the density of ""dark""surface spins to interrogate their contribution to the decoherence of shallow NV center spin qubits. When the average surface spin spacing exceeds the NV center depth, we find that the surface spin contribution to the NV center free induction decay can be described by a stretched exponential with variable power n. We show that these observations are consistent with a model in which the spatial positions of the surface spins are fixed for each measurement, but some of them reconfigure between measurements. In particular, we observe a depth-dependent critical time associated with a dynamical transition from Gaussian (n=2) decay to n=2/3, and show that this transition arises from the competition between the small decay contributions of many distant spins and strong coupling to a few proximal spins at the surface. These observations demonstrate the potential of a local sensor for understanding complex systems and elucidate pathways for improving and controlling spin qubits at the surface.","","en","journal article","","","","","","","","","","","QID/Dobrovitski Group","","",""
"uuid:d0435cf9-7bc5-488c-b838-b1e9835127d2","http://resolver.tudelft.nl/uuid:d0435cf9-7bc5-488c-b838-b1e9835127d2","Microstructural basis for improved corrosion resistance and mechanical properties of fabricated ultra-fine grained Mg-Akermanite composites","Mehdizade, M. (Iran University of Science and Technology); Eivani, A.R. (Iran University of Science and Technology); Tabatabaei, F. (Iran University of Science and Technology); Jafarian, H. R. (Iran University of Science and Technology); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2022","In the present research, a composite with a magnesium alloy (WE43) as the matrix and Akermanite as the bioactive and reinforcing agent was fabricated by friction stir processing (FSP), resulting in a microstructure with uniformly distributed fine grains, second-phase particles and micro-sized Akermanite particles. The effect of an addition of Akermanite to the alloy on the mechanical properties and corrosion resistance of the resulting composite was investigated. The compressive strength and ductility of the composite were found to be significantly higher than those of the monolithic WE43 alloy. The value of yield strength of the WE43 sample increased from 75 MPa up to 119 and 225 MPa for WE43-6P and WE43-A-6P samples, respectively. Also, the value of the ultimate compressive strength of the WE43 sample increased from 210 MPa up to 240 and 362 MPa for WE43-6P and WE43-A-6P samples, respectively. The value of elongation for WE43, WE43-6P, and WE43-A-6P samples were 4.5%, 16%, and 22%, respectively. The EIS test showed that the corrosion mechanism of WE43 sample is a combination of localized pitting and uniform corrosion, which shifted towards more uniform corrosion with higher corrosion resistance by applying FSP and adding Akermanite powder. The potentiodynamic polarization and in vitro immersion tests confirmed this finding, as evidenced by the increase in polarization resistance from 0.192 for the monolithic WE43 alloy up to 0.339 and 0.609 kΩ/cm2 for WE43-6P and WE43-A-6P samples, respectively. The mass loss rate of the WE43 sample decreased from 20.82 to 10.13 mm per year for the WE43-A-6P sample after 312 h immersion in SBF solution. All tests approved that by applying FSP and adding Akermanite to WE43, the corrosion resistance in the SBF solution could be significantly enhanced.","Akermanite; Composite; Corrosion; Friction stir processing; Magnesium","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:488cad9d-badf-4818-8cb2-1b28d5d44c01","http://resolver.tudelft.nl/uuid:488cad9d-badf-4818-8cb2-1b28d5d44c01","The First Multimodal Information Based Speech Processing (Misp) Challenge: Data, Tasks, Baselines And Results","Chen, Hang (University of Science and Technology of China); Zhou, Hengshun (University of Science and Technology of China); Du, Jun (University of Science and Technology of China); Lee, Chin-Hui (Georgia Institute of Technology); Chen, Jingdong (Northwestern Polytechnical University); Watanabe, Shinji (Carnegie Mellon University); Siniscalchi, Sabato Marco (Georgia Institute of Technology; University of Enna Kore); Scharenborg, O.E. (TU Delft Multimedia Computing); Liu, Di-Yuan (iFlytek)","","2022","In this paper we discuss the rational of the Multi-model Information based Speech Processing (MISP) Challenge, and provide a detailed description of the data recorded, the two evaluation tasks and the corresponding baselines, followed by a summary of submitted systems and evaluation results. The MISP Challenge aims at tack-ling speech processing tasks in different scenarios by introducing information about an additional modality (e.g., video, or text), which will hopefully lead to better environmental and speaker robustness in realistic applications. In the first MISP challenge, two bench-mark datasets recorded in a real-home TV room with two reproducible open-source baseline systems have been released to promote research in audio-visual wake word spotting (AVWWS) and audio-visual speech recognition (AVSR). To our knowledge, MISP is the first open evaluation challenge to tackle real-world issues of AVWWS and AVSR in the home TV scenario.","MISP challenge; microphone array; audio-visual; automatic speech recognition; wake word spotting","en","conference paper","IEEE","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Multimedia Computing","","",""
"uuid:74fc0816-0901-423d-b917-365574bf24a3","http://resolver.tudelft.nl/uuid:74fc0816-0901-423d-b917-365574bf24a3","Audio-Visual Wake Word Spotting in MISP2021 Challenge: Dataset Release and Deep Analysis","Zhou, Hengshun (University of Science and Technology of China); Du, Jun (University of Science and Technology of China); Zou, Gongzhen (University of Science and Technology of China); Nian, Zhaoxu (University of Science and Technology of China); Lee, Chin Hui (Georgia Institute of Technology); Siniscalchi, Sabato Marco (Georgia Institute of Technology; University of Enna Kore); Watanabe, Shinji (Carnegie Mellon University); Scharenborg, O.E. (TU Delft Multimedia Computing); Chen, Jingdong (Northwestern Polytechnical University)","","2022","In this paper, we describe and release publicly the audio-visual wake word spotting (WWS) database in the MISP2021 Challenge, which covers a range of scenarios of audio and video data collected by near-, mid-, and far-field microphone arrays, and cameras, to create a shared and publicly available database for WWS. The database and the code 2 are released, which will be a valuable addition to the community for promoting WWS research using multi-modality information in realistic and complex conditions. Moreover, we investigated the different data augmentation methods for single modalities on an end-to-end WWS network. A set of audio-visual fusion experiments and analysis were conducted to observe the assistance from visual information to acoustic information based on different audio and video field configurations. The results showed that the fusion system generally improves over the single-modality (audio- or video-only) system, especially under complex noisy conditions.","analysis; audio-visual database; data augmentation; Wake word spotting","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Multimedia Computing","","",""
"uuid:eedbec39-ee44-4d87-9b7c-8687bf524241","http://resolver.tudelft.nl/uuid:eedbec39-ee44-4d87-9b7c-8687bf524241","Additive manufacturing of bioactive and biodegradable porous iron-akermanite composites for bone regeneration","Putra, N.E. (TU Delft Biomaterials & Tissue Biomechanics); Borg, K. G.N. (Student TU Delft); Diaz Payno, P.J. (TU Delft Biomaterials & Tissue Biomechanics; Erasmus MC); Leeflang, M.A. (TU Delft Biomaterials & Tissue Biomechanics); Klimopoulou, M. (TU Delft Biomaterials & Tissue Biomechanics); Taheri, P. (TU Delft Team Peyman Taheri); Mol, J.M.C. (TU Delft Team Arjan Mol); Fratila-Apachitei, E.L. (TU Delft Biomaterials & Tissue Biomechanics); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2022","Advanced additive manufacturing techniques have been recently used to tackle the two fundamental challenges of biodegradable Fe-based bone-substituting materials, namely low rate of biodegradation and insufficient bioactivity. While additively manufactured porous iron has been somewhat successful in addressing the first challenge, the limited bioactivity of these biomaterials hinder their progress towards clinical application. Herein, we used extrusion-based 3D printing for additive manufacturing of iron-matrix composites containing silicate-based bioceramic particles (akermanite), thereby addressing both of the abovementioned challenges. We developed inks that carried iron and 5, 10, 15, or 20 vol% of akermanite powder mixtures for the 3D printing process and optimized the debinding and sintering steps to produce geometrically-ordered iron-akermanite composites with an open porosity of 69–71%. The composite scaffolds preserved the designed geometry and the original α-Fe and akermanite phases. The in vitro biodegradation rates of the composites were improved as much as 2.6 times the biodegradation rate of geometrically identical pure iron. The yield strengths and elastic moduli of the scaffolds remained within the range of the mechanical properties of the cancellous bone, even after 28 days of biodegradation. The composite scaffolds (10–20 vol% akermanite) demonstrated improved MC3T3-E1 cell adhesion and higher levels of cell proliferation. The cellular secretion of collagen type-1 and the alkaline phosphatase activity on the composite scaffolds (10–20 vol% akermanite) were, respectively higher than and comparable to Ti6Al4V in osteogenic medium. Taken together, these results clearly show the potential of 3D printed porous iron-akermanite composites for further development as promising bone substitutes. Statement of significance: Porous iron matrix composites containing akermanite particles were produced by means of multi-material additive manufacturing to address the two fundamental challenges associated with biodegradable iron-based biomaterials, namely very low rate of biodegradation and insufficient bioactivity. Our porous iron-akermanite composites exhibited enhanced biodegradability and superior bioactivity compared to porous monolithic iron scaffolds. The murine bone cells proliferated on the composite scaffolds, and secreted the collagen type-1 matrix that stimulated bony-like mineralization. The results show the exceptional potential of the developed porous iron-based composite scaffolds for application as bone substitutes.","Akermanite; Biodegradable; Bone substitution; Composite; Extrusion-based 3D printing; Iron; Scaffold","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:34d51c5a-7a36-4165-aa16-0b9e955bb11c","http://resolver.tudelft.nl/uuid:34d51c5a-7a36-4165-aa16-0b9e955bb11c","Application of abandoned wells integrated with renewables","Zhou, Yuekuan (The Hong Kong University of Science and Technology); Liu, Zhengxuan (TU Delft Design & Construction Management; Hunan University); Xing, Chaojie (Hunan University)","","2022","The large thermal potentials with geothermal gradient of abandoned wells provide the possibility and opportunity for carbon-neutrality transition of district heating systems, whereas energy harvesting from abandoned geothermal wells is full of challenges, due to the considerable initial investment in economic cost, system performance degradation, and so on. In this chapter, a systematic and comprehensive review on the application techniques of abandoned wells is presented, in terms of advanced thermal/power conversions, renewable integrations for district heating, and strategies for performance enhancement. Discussions on real applications have been conducted and future prospects presented, from perspectives of lifetime system performance, techno-economic feasibility analysis, and potential assessment of abandoned wells for carbon-neutrality transition. The results of this chapter can provide preliminary knowledge and cutting-edge technologies on renewable integrations with abandoned wells, so as to demonstrate techno-economic-environmental potentials of abandoned wells and contributions toward carbon-neutrality transition.","Abandoned wells; Geothermal energy; Renewable energy; Smart controllers; Techno-economic feasibility","en","book chapter","Elsevier","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Design & Construction Management","","",""
"uuid:40920e0d-ef7f-49f8-b979-73fed64baf68","http://resolver.tudelft.nl/uuid:40920e0d-ef7f-49f8-b979-73fed64baf68","The main utilization forms and current developmental status of geothermal energy for building cooling/heating in developing countries","Liu, Zhengxuan (TU Delft Design & Construction Management; Hunan University); Xing, Chaojie (Hunan University); Zeng, Chao (Southwest Jiaotong University); Zhou, Yuekuan (The Hong Kong University of Science and Technology)","","2022","Geothermal energy (GE), as an ideal renewable resource for building cooling/heating with stability and abundance in energy supply, has been widely exploited in developing countries. The common utilization forms of GE mainly include the ground source heat pump (GSHP), underground duct system (UDS), and abandoned wells energy (AWE) system. However, there is still a lack of comprehensive overview of the current developmental status of the GSHP, UDS, and AWE systems for building cooling/heating in developing countries. This chapter will be conducted from the following aspects: (1) The literature review and categories of GE utilization in the developing countries, mainly including the latest literature review on GE development and categories of utilization for building cooling/heating. (2) The common utilization of the GSHP system and its current application and development in the developing countries, mainly including the ground-coupled heat pump (GCHP) system and groundwater heat pump (GWHP) system. (3) The common utilization of the UDS system and its current application and development in the developing countries, mainly including the horizontal UDS system, vertical UDS system, and the corresponding coupled system with phase change energy storage and other advanced technologies. (4) The common utilization of the AWE system and its current application and development in the developing countries, mainly including the abandoned oil and gas wells. (5) The existing issues and in-depth analysis on the practical application of GE for building cooling/heating in the developing countries. This chapter can provide some effective guidelines on the various GE utilization forms for building cooling/heating in developing countries.","Abandoned wells energy; Building cooling/heating; Developing countries; Geothermal energy; Ground source heat pump; Underground duct system","en","book chapter","Elsevier","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Design & Construction Management","","",""
"uuid:ba0d1128-f27c-4796-9271-1382d8389b36","http://resolver.tudelft.nl/uuid:ba0d1128-f27c-4796-9271-1382d8389b36","Steel Slag Aggregate Characteristics Evaluation as Railway Ballast","Jing, Guoqing (Beijing Jiaotong University); Aela, Peyman (Beijing Jiaotong University); Zhou, Qiang (Beijing Jiaotong University); Jia, W. (TU Delft Railway Engineering)","Tutumluer, Erol (editor); Nazarian, Soheil (editor); Al-Qadi, Imad (editor); Qamhia, Issam I. A. (editor)","2022","The use of recycled materials is a new tendency in the field of railway engineering. Steel slag aggregates (SSA) are one of the recycled materials derived from the steel industry. The application of SSA in ballasted railway tracks requires mechanical examination. In the present paper, the shear behavior of the ballast layer constructed by SSA and basalt aggregates was considered to assess the use of SSA as a substitution for basalt. In this regard, a series of large-direct shear tests were performed on basalt and SSA under various normal stresses. Based on the results, basalt aggregates have higher shear resistance than SSA for all normal stress. However, steel slag has sufficient shear strength as well as particle abrasion resistance. Overall, it was proven that the SSA has suitable stability against shear forces that could be applied on railway ballast.","Basalt; LA abrasion; Large-direct shear test; Shear resistance; SSA","en","conference paper","Springer","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Railway Engineering","","",""
"uuid:cc6848ff-ee93-4af8-a322-5b27d354da7f","http://resolver.tudelft.nl/uuid:cc6848ff-ee93-4af8-a322-5b27d354da7f","Lateral Flows and Sediment Dynamics in a Large Engineered Estuary","Zhou, Z. (TU Delft Coastal Engineering)","Wang, Zhengbing (promotor); Ding, Ping Xing (promotor); van Maren, D.S. (promotor); Delft University of Technology (degree granting institution)","2021","Estuaries are partially enclosed water bodies where river water mixes with sea water. Estuaries provide important ecological functions which are strongly regulated by estuarine hydrodynamics and sediment dynamics, and also by human interventions. Sustainable management of such systems therefore requires a thorough understanding of the interplay between hydrodynamics, sediment dynamics, and human interventions. However, estuaries are often complex systems influenced by river runoff and coastal hydrodynamics (tide, wind, and wave), which all interact with human interventions on various time and spatial scales. Our understanding of estuaries is still insufficient to understand the response of strongly engineered systems to both human interventions and to natural fluctuations. Many estuaries worldwide are strongly influenced by a wide range of human interventions, including engineering constructions, deepening, and land reclamations. An example of highly engineered estuaries is the Changjiang Estuary (CE), China. The upstream river discharge and sediment load is strongly influenced by the Three Gorges Dam (TGD), a multi-purpose dam in the Changjiang River aiming at optimizing flood control and irrigation, and generate hydropower. In the North Passage (NP), an outlet and the main navigation channel of the CE, the Deepwater Navigation Channel (DNC) has been constructed to improve channel navigability. The DNC project includes constructions of dikes and groynes, and regular dredging work. These various interventions strongly influence estuarine hydro- and sediment dynamics but take place concurrently, and therefore their individual impact is not straightforward to assess. A better understanding of the impact of these interventions requires systematic analysis of hydrodynamic and sediment transport processes in relation to the interventions. This dissertation aims to unravel the effect of groynes on lateral flows and sediment transport in a tidal channel-shoal system (i.e. the NP). Groyne fields provide buffer zones, with a salinity lagging behind that in the main navigation channel. The resulting lateral salinity gradients drive lateral density currents, which in turn modify longitudinal salinity gradients in the main channel. These salinity-driven currents also impact the lateral sediment exchange between the main channel and the groyne fields. The effects of groynes on lateral flows and lateral sediment exchange are analyzed using numerical simulations in combination with in-situ observations. Water-bed sediment exchange processes are investigated in more detail using measurements collected with two tripods deployed in the CE. Measured bed level changes are analyzed by semi-automatically fitting the Krone-Partheniades equations to the bed level data using observations of velocity and sediment concentration. This method provides continuous timeseries of sediment properties related to erosion and deposition. It is demonstrated that the erosion parameters are strongly fluctuating, and not constant as typically assumed in numerical models. Such a variability needs to be reflected in a model, either by time-varying parameters or including more detailed processes (for example, consolidation). This dissertation introduces a method to obtain a parameter space that includes the values and accuracies of all potential combinations of input parameters, which is important input for morphodynamic models. To further quantify effects of groynes on hydrodynamics and sediment dynamics, an idealized hydrodynamic model with a single channel with groynes is developed and analyzed. The idealized system has geometric features comparable to the NP, but is set up in such a way that the groyne field aspect ratios (the ratio of the distance between contiguous groynes to the length of groynes) can be systematically investigated. Model results reveal that groynes can influence channel hydrodynamics and local mixing conditions, which influence lateral flows and the longitudinal salt intrusion. Salt intrusion is highest for intermediate aspect ratios, but weaker for very wide or narrow groyne fields. These results highlight the complexity of the hydrodynamics in salt fresh-water transition zones, and specifically the role of human intervention thereon.","hydrodynamics; lateral flows; sediment dynamics; sediment transport; dikes and groynes; salt intrusion","en","doctoral thesis","","9789464235609","","","","","","","","","Coastal Engineering","","",""
"uuid:10562ad6-ef0c-417c-9c89-f9668cc8eba6","http://resolver.tudelft.nl/uuid:10562ad6-ef0c-417c-9c89-f9668cc8eba6","On the formation mechanisms and properties of MAX phases: A review","Zhang, Z. (TU Delft Novel Aerospace Materials; Harbin Institute of Technology); Duan, X. (TU Delft OLD Surface and Interface Engineering; Harbin Institute of Technology); Jia, Dechang (Harbin Institute of Technology); Zhou, Y. (TU Delft PLD Infra & construction; Harbin Institute of Technology); van der Zwaag, S. (TU Delft Novel Aerospace Materials)","","2021","MAX phases are a family of ternary carbide or nitride ceramics possessing a layered crystal structure and, due to their chemical bonds having a mixed covalent-ionic-metallic nature, have unique properties combining those of metals and ceramics. In this review, the formation mechanisms of MAX phases from elemental and compound powders are reviewed in detail, as the formation mechanisms are closely related to the unique properties of well-synthesized MAX phases. The stability of MAX phases in some harsh external environments is significantly influenced by the defect population, allowing the mechanisms of defect formation and migration to strongly influence their self-healing performance and radiation tolerance. The properties of MAX phases can be tailored by creating solid solutions, which have lattice distortions, and texturing which results in the preferential orientation of plate-like grains.","Formation mechanisms; MAX phases; Point defects; Solid solutions; Texture","en","review","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2021-09-13","","","Novel Aerospace Materials","","",""
"uuid:467f9f64-ae55-4e66-be24-0d0cb5f46fc4","http://resolver.tudelft.nl/uuid:467f9f64-ae55-4e66-be24-0d0cb5f46fc4","Novel applications of ground-penetrating radar in oil fields","Zhou, F. (TU Delft Applied Geophysics and Petrophysics)","Slob, E.C. (promotor); Delft University of Technology (degree granting institution)","2021","Ground-penetrating radar (GPR), usually working in the frequency from tens of megahertz to several gigahertz, is widely applied in mapping near-surface applications. In recent decades, GPR is frequently utilized for fluid-related applications, such as groundwater assessment, contaminant monitoring, and water-filled fracture detection, based on the principle that at these radar frequencies, electromagnetic (EM) waves are sensitive to water content. When operated from the surface, ground-penetrating radars are limited to a survey depth up to tens of meters in most soils. To further extend the detection range, borehole radar is developed by placing the GPR antennas in boreholes close to the underground targets. Different downhole survey modes, e.g. single-hole, cross-hole, and vertical radar profiling measurements, have demonstrated applicabilities for fracture detection, metal ore exploration, or water content prediction, up to a depth of a few hundred meters from the ground. Deeper GPR measurements in hydrocarbon reservoirs have been proposed. Some theoretical studies have shown that a borehole radar is expected to have the capability of mapping structures in the range of a few decimeters to ten meters away from the borehole in most reservoir environments, filling in the gap of the conventional electrical, sonic and nuclear logging methods. More attractively, GPR has a relatively high radial resolution and suits best for the downhole structure and fluid imaging. This thesis aims to explore the potential applications of GPR and assess their values in these oil industry applications. Applicability studies are carried out in the fields of well logging and monitoring of oil production. Numerical simulations are carried out, where joint multiphase flow and borehole radar modelling is established.","Ground-penetrating radar; Borehole geophysics; Enhanced oil recovery; Reservoir estimation","en","doctoral thesis","","978-94-6384-183-2","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:6e12be22-c1ec-4f02-9c4f-8a43e539c947","http://resolver.tudelft.nl/uuid:6e12be22-c1ec-4f02-9c4f-8a43e539c947","Simulation of deformation and fracture initiation during equal channel angular pressing of AZ31 magnesium alloy with covered tube casing","Eivani, A.R. (Iran University of Science and Technology); Mirghasemi, S. M. (Iran University of Science and Technology); Seyedein, S. H. (Iran University of Science and Technology); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Jafarian, H. R. (Iran University of Science and Technology)","","2021","The present research was aimed at lowering the deformation temperature by applying cover tube casing (CTC) to AZ31 magnesium alloy samples subjected to equal channel angular pressing (ECAP) without triggering surface defects and/or fracture. The Cockcroft-Latham (C & L) fracture model was incorporated into finite element simulation and the critical values for a fracture to occur were determined. The fracture was predicted for the samples deformed at 150, 175, and 200 °C without CTC and with CTC having thicknesses of 1 and 4 mm. The predictions of the model were verified with experimental data. It was found that the workability of AZ31 increased with increasing CTC thickness, as a result of a reduction in the maximum principal stress at the top surface, a uniform distribution of strains, and an increase in the critical damage. In practice, the use of CTC led to the possibility of a reduction in deformation temperature by 25 °C. A sound product with a homogeneous grain structure and a mean grain size of 11 μm was achieved at 175 °C. Thus, the ECAP working window for the alloy was enlarged with accompanying benefits in energy consumption, tooling life, and manufacturing costs.","Equal channel angular pressing; Finite element simulation; Fracture; Magnesium; Workability","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:cbaf4b3d-3d5b-45d9-b003-b39ca4a96661","http://resolver.tudelft.nl/uuid:cbaf4b3d-3d5b-45d9-b003-b39ca4a96661","Applying multi-pass friction stir processing to refine the microstructure and enhance the strength, ductility and corrosion resistance of WE43 magnesium alloy","Eivani, A.R. (Iran University of Science and Technology); Mehdizade, M. (Iran University of Science and Technology); Chabok, S. (Iran University of Science and Technology); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2021","Magnesium alloys have many unique properties, mostly benefitting from the low density of magnesium. However, they are not competitive, when compared with other lightweight materials, such as aluminum alloys, particularly in ductility and corrosion resistance. There is a strong need to improve the mechanical properties and corrosion resistance of magnesium alloys. In the present research, friction stir processing (FSP) as a severe plastic deformation process was applied to the WE43 magnesium alloy. The effect of FSP up to 6 passes on the grain structure, second-phase particle distribution, mechanical properties and corrosion resistance of the alloy was investigated. It was found that a continuous network of second-phase particles was present at the grain boundaries, which was considered to be one of the main causes for the poor ductility of the alloy in the as-annealed state. By applying two passes of FSP, the grain structure was significantly refined, changing from an average grain size of 12.4 to 2.5 μm. By further FSP, the grain structure continued to refine to an average grain size of 1.4 μm after 4 passes and remained unchanged after 6 passes. However, the fragmentation and redistribution of second-phase particles continued to occur during the 4th and 6th passes of FSP. Because of these microstructural changes, the uniform strain to maximum stress and the strength of specimens gradually improved with increasing number of FSP passes. The corrosion resistance of the alloy was found to be improved by applying 6 passes of FSP, compared to that of the alloy in the initial as-annealed state, which was attributed to the fragmentation and redistribution of second-phase particles. By applying FSP, the uniformity of the protective passive layer was improved and, in the meantime, the intensity of micro-galvanic coupling leading to pitting corrosion was decreased.","Corrosion; Friction stir processing; Magnesium; Mechanical properties; Microstructure","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:35d99488-a26a-4de6-90bc-cafac653d708","http://resolver.tudelft.nl/uuid:35d99488-a26a-4de6-90bc-cafac653d708","Stable Spinning Deployment Control of a Triangle Tethered Formation System","Zhang, Fan (Northwestern Polytechnical University); Zhou, He (Northwestern Polytechnical University); Huang, Panfeng (Northwestern Polytechnical University); Guo, J. (TU Delft Space Systems Egineering)","","2021","The tethered formation system has been widely studied due to its extensive use in aerospace engineering, such as Earth observation, orbital location, and deep space exploration. The deployment of such a multitethered system is a problem because of the oscillations and complex formation maintenance caused by the space tether's elasticity and flexibility. In this article, a triangle tethered formation system is modeled, and an exact stable condition for the system's maintaining is carefully analyzed, which is given as the desired trajectories; then, a new control scheme is designed for its spinning deployment and stable maintenance. In the proposed scheme, a novel second-order sliding mode controller is given with a designed nonsingular sliding-variable. Based on the theoretical proof, the addressed sliding variable from the arbitrary initial condition can converge to the manifold in finite time, and then sliding to the equilibrium in finite time as well. The simulation results show that compared with classic second sliding-mode control, the proposed scheme can speed up the convergence of the states and sliding variables.","Mathematical model; Orbits; Sliding mode control; Space missions; Space stations; Space vehicles; Spinning; Stable and spinning deployment; tethered satellites system; triangle formation","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Space Systems Egineering","","",""
"uuid:4cfa58d6-d49a-4481-bb3a-e7819e9dafbf","http://resolver.tudelft.nl/uuid:4cfa58d6-d49a-4481-bb3a-e7819e9dafbf","Technical considerations in the Verasonics research ultrasound platform for developing a photoacoustic imaging system","Kratkiewicz, Karl (Wayne State University); Manwar, Rayyan (University of Illinois at Chicago); Zhou, Yang (Wayne State University); Mozaffarzadeh, M. (TU Delft ImPhys/Medical Imaging); Avanaki, Kamran (University of Illinois at Chicago)","","2021","Photoacoustic imaging (PAI) is an emerging functional and molecular imaging technology that has attracted much attention in the past decade. Recently, many researchers have used the vantage system from Verasonics for simultaneous ultrasound (US) and photoacoustic (PA) imaging. This was the motivation to write on the details of US/PA imaging system implementation and characterization using Verasonics platform. We have discussed the experimental considerations for linear array based PAI due to its popularity, simple setup, and high potential for clinical translatability. Specifically, we describe the strategies of US/PA imaging system setup, signal generation, amplification, data processing and study the system performance.","","en","journal article","","","","","","","","","","","ImPhys/Medical Imaging","","",""
"uuid:b3f4ef40-803d-420d-8717-2e2e5cc4f66b","http://resolver.tudelft.nl/uuid:b3f4ef40-803d-420d-8717-2e2e5cc4f66b","Simulation framework for activity recognition and benchmarking in different radar geometries","Zhou, Boyu (University of Electronic Science and Technology of China); Lin, Yier (University of Electronic Science and Technology of China); Le Kernec, Julien (University of Glasgow; University of Electronic Science and Technology of China; University of Cergy-Pontoise); Yang, Shufan (University of Glasgow); Fioranelli, F. (TU Delft Microwave Sensing, Signals & Systems); Romain, Olivier (University of Cergy-Pontoise); Zhao, Zhiqin (University of Electronic Science and Technology of China)","","2021","Radar micro-Doppler signatures have been proposed for human monitoring and activity classification for surveillance and outdoor security, as well as for ambient assisted living in healthcare-related applications. A known issue is the performance reduction when the target is moving tangentially to the line of sight of the radar. Multiple techniques have been proposed to address this, such as multistatic radar and to some extent, interferometric (IF) radar. A simulator is presented to generate synthetic data representative of eight radar systems (monostatic, circular multistatic and in-line multistatic [IM] and IF) to quantify classification performances as a function of aspect angles and deployment geometries. This simulator allows an unbiased performance evaluation of different radar systems. Six human activities are considered with signatures originating from motion-captured data of 14 different subjects. The classification performances are analysed as a function of aspect angles ranging from 0° to 90° per activity and overall. It demonstrates that IF configurations are more robust than IM configurations. However, IM performs better at angles below 55° before IF configurations take over.","","en","journal article","","","","","","","","","","","Microwave Sensing, Signals & Systems","","",""
"uuid:15d3760c-89f3-4189-aabf-8c1b91e075c3","http://resolver.tudelft.nl/uuid:15d3760c-89f3-4189-aabf-8c1b91e075c3","A case study for scientific research prior to conservation of marine metal artefacts","van der Stok-Nienhuis, Janneke (Universiteit van Amsterdam); Kuiper, Elisabeth (Universiteit van Amsterdam); Beentjes, Tonny (Universiteit van Amsterdam); Joosten, Ineke (Cultural Heritage Agency of the Netherlands); van Eijck, L. (TU Delft RST/Neutron and Positron Methods in Materials); Zhou, Z. (TU Delft RST/Neutron and Positron Methods in Materials); van Bommel, Maarten (Universiteit van Amsterdam)","","2021","A rare find of a high-status 17th century oval box, retrieved from a shipwreck, provided a unique opportunity to research the construction and finishing layers of an object that is untouched for 350 years. This case study was used to demonstrate the extent of data that can be gained from analytical techniques prior to conservation. The amalgam-gilt brass object was studied by optical and electron microscopy, X-radiography, micro-computed X-ray tomography, neutron tomography, X-ray fluorescence, X-ray diffraction, Rutherford backscattering spectrometry, proton-induced X-ray emission and gas chromatography. The results have led to a characterisation of the manufacturing methods used on the box and to a better understanding of the practicality of modern analytical methods and techniques in (maritime) archaeological research.","17th century; Conservation; Gilt brass; Maritime archaeology; Possibilities and limitations analytical techniques; Technical art history","en","journal article","","","","","","","","","","","RST/Neutron and Positron Methods in Materials","","",""
"uuid:6a5eb501-dc8b-4334-81bf-447fd1ac83f6","http://resolver.tudelft.nl/uuid:6a5eb501-dc8b-4334-81bf-447fd1ac83f6","Sediment Characteristics and Intertidal Beach Slopes along the Jiangsu Coast, China","Kuai, Y. (TU Delft Coastal Engineering); Tao, Jianfeng (Hohai University); Zhou, Z. (TU Delft Coastal Engineering; East China Normal University); Aarninkhof, S.G.J. (TU Delft Hydraulic Engineering); Wang, Zhengbing (TU Delft Coastal Engineering; Deltares)","","2021","Tidal flats play an important role in promoting coastal biodiversity, defense against flooding, land reclamation and recreation. Many coastal tidal flats, especially the tide-dominant ones, are muddy. However, the number of studies on the profile shape and surficial sediment distribution of muddy tidal flats is small compared to sandy beaches. Based on high spatial-resolution measurements along the tide-dominant Jiangsu Coast, China, we analyzed the morphology and sediment characteristics of the unvegetated intertidal flats along the Jiangsu Coast. The Jiangsu Coast can be divided into an eroding northern part (north coast) and an accreting southern part (south coast). The beach slope of the north coast shows a southward flattening trend, apart from some outliers related to rocky parts of the coastline. We found alternating very fine and coarse sediment (depending on the local clay content) for different locations along the north coast, which can be explained from consolidation and armoring-induced erosion resistance. In the south coast, we found gradual coarsening of bed surface sediment and gradual flattening of beach slopes to the south. This seemingly unexpected pattern is explained by the flood-dominant current causing landward sediment transport, larger tidal range in the south part, sheltering effect of the Radial Sand Ridges, and contribution of different sediment sources, viz. the Abandoned Yellow River Delta and the Radial Sand Ridges. In the cross-shore direction, the sediment grain size decreases landward. Waves are only of secondary importance for the sediment dynamics at the unvegetated tidal flats along the Jiangsu Coast.","Beach slope; Human intervention; Intertidal beach; Jiangsu Coast; Surficial sediment grain-size","en","journal article","","","","","","","","","","Hydraulic Engineering","Coastal Engineering","","",""
"uuid:4ca74907-f71b-4098-8e3e-dbfbba131212","http://resolver.tudelft.nl/uuid:4ca74907-f71b-4098-8e3e-dbfbba131212","Enabling Supply Chain Visibility and Compliance Through Voluntary Information Sharing with Customs: A Case Study of the Global Quality Traceability System in China Customs","Zhou, Xin (Shanghai Customs College); Tan, Y. (TU Delft Information and Communication Technology); Rukanova, B.D. (TU Delft Information and Communication Technology)","","2021","The promotion of digital customs and data analytics have led customs administrations to seek to improve their analytics capabilities and exploit data from the trade community. Despite the increased data analysis capabilities of Customs, the data available to them are still limited to the current mandated declaration. If businesses are willing to share additional commercial information with Customs, it will enable them to make a more accurate risk assessment and ensure compliance. As a new form of Customs and business partnership, voluntary information sharing can be a supplementary data source to the mandated declaration and enable Customs to exploit additional commercial information. This study analysed an exploratory case study on the Global Quality Traceability System (GQTS) initiated by China Customs to investigate how voluntary information sharing can be achieved, and to explore the benefits for the participants. This study demonstrated that voluntary information sharing with Customs implemented through a data pipeline enhanced supply chain visibility and ensured compliance. The private companies who shared information contributed to the supply chain visibility and in return benefited from it.","","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-02-01","","","Information and Communication Technology","","",""
"uuid:5ade4a31-f6ff-4685-ad20-1a599f2ac667","http://resolver.tudelft.nl/uuid:5ade4a31-f6ff-4685-ad20-1a599f2ac667","Optimal Estimate of Global Biome: Specific Parameter Settings to Reconstruct NDVI Time Series with the Harmonic ANalysis of Time Series (HANTS) Method","Zhou, J. (TU Delft Optical and Laser Remote Sensing; Central China Normal University); Jia, Li (Chinese Academy of Sciences); Menenti, M. (TU Delft Optical and Laser Remote Sensing; Chinese Academy of Sciences); Liu, Xuan (Central China Normal University)","","2021","Terrestrial remote sensing data products retrieved from radiometric measurements in the optical and thermal infrared spectrum such as vegetation spectral indices can be heavily contaminated by atmospheric conditions, including cloud and aerosol layers. This contamination results in gaps or noisy observations. The harmonic analysis of time series (HANTS) has been widely used for time series reconstruction of remote sensing imagery in recent decades. To use HANTS model, a series of parameters, such as number of frequencies (NF), fitting error tolerance (FET), degree of over-determinedness (DoD), and regularization factor (Delta), need to be defined by users. These parameters provide flexibilities, but also make it difficult for non-expert users to determine appropriate settings for specific applications. This study systematically evaluated the reconstruction performance of the model under different parameter setting scenarios by simulating pixel-wise reference and noisy NDVI time series. The results of these numerical experiments were further used to identify optimal settings and improve global NDVI reconstruction performance. The results suggested optimal settings for different areas (local optimization). If a user opts to use unique settings for global reconstruction, the setting NF = 4, FET = 0.05, DoD = 5, and Delta = 0.5 can produce the best performance across all setting scenarios (global optimization). In addition, several internal improvements, such as dynamic weighting scheme, polynomial and inter-annual harmonic components, and ancillary attributes of input data can be used to further improve the performance of reconstruction. With these results, future non-expert users can easily determine appropriate settings of HANTS for specific applications in different regions.","NDVI; HANTS; harmonic analysis; gap-filling; time series","en","journal article","","","","","","","","","","","Optical and Laser Remote Sensing","","",""
"uuid:dce6d6a2-2568-4b0c-a94e-440bc0159d16","http://resolver.tudelft.nl/uuid:dce6d6a2-2568-4b0c-a94e-440bc0159d16","Hydraulic characteristics of emerged rigid and submerged flexible vegetations in the riparian zone","Meng, Xin (Zhejiang University); Zhou, Y. (TU Delft Materials- Mechanics- Management & Design); Sun, Zhilin (Zhejiang University); Ding, Kaixuan (Zhejiang University); Chong, Lin (Zhejiang University)","","2021","Flow resistance, velocity distribution, and turbulence intensity are significantly influenced by aquatic vegetations (AV) in riparian zones. Understanding the hydraulics of flow with planted floodplains is of great significance for determining the velocity distribution profile and supporting the fluvial processes management. However, the traditional flume experiment method is inefficient. Therefore, the multigroup simultaneous flume test method was carried out to describe the flow patterns affected by emerged rigid (reed and wooden stick) and submerged flexible vegetations (grass and chlorella). The Acoustic Doppler Velocimeter (ADV) was utilized to measure the velocity at one point for different experimental conditions. The results showed that hydraulic features were influenced by different types of vegetation. Furthermore, the relative depth (z/h) was a determining factor of those variations. In addition, the time-averaged velocity distributions of planted floodplains are not logarithmic. Instead, they represented “s-shape” profiles. In detail, for the vegetated floodplains, reed and wood followed an s-shape profile, but for grass and chlorella, they followed reverse s-shape profile. For all cases, turbulence is not isotropic and the change law of turbulence intensity is different in different sections. The flow resistance, turbulence intensities, and Reynold stresses influenced by different types of vegetation were also analyzed.","Flow resistance; Flume experiment; Reynold stress; Vegetated flow","en","journal article","","","","","","","","","","Materials- Mechanics- Management & Design","","","",""
"uuid:306a555b-c312-40c3-898f-91b1c131b56b","http://resolver.tudelft.nl/uuid:306a555b-c312-40c3-898f-91b1c131b56b","Recent applications of biological technologies for decontaminating hormones in livestock waste and wastewater","Zhou, Xinyan (Zhejiang Agriculture and Forestry University); Zheng, Huabao (Zhejiang Agriculture and Forestry University); van der Hoek, J.P. (TU Delft Sanitary Engineering; Waternet); Yu, Kefei (Zhejiang Agriculture and Forestry University); Cao, Yucheng (Zhejiang Agriculture and Forestry University)","","2021","Large quantities of natural and synthetic hormones contained in livestock waste and wastewater (LWW) can cause serious problems in our environment. Composting and anaerobic digestion cannot remove hormones efficiently, so they should be modified to enhance the treatment processes. In addition, constructed wetlands show decent rates for removal of hormones. Advanced technologies such as membrane biological reactors and microalgae-based systems efficiently eliminate hormones from LWW. However, more practical studies are needed to investigate their actual performances. The categories, degradation mechanisms, and enzymes of hormone-degrading microorganisms are presented, and related hormone-degrading microorganism-based technologies are introduced. Finally, composting, anaerobic digestion, constructed wetlands, membrane biological reactors, and microalgae-based systems are compared in terms of their applicability in LWW treatment.","Membrane biological reactors; Microalgae-based systems; Composting; Constructed wetlands; Hormones; Anaerobic digestion","en","review","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-06-30","","","Sanitary Engineering","","",""
"uuid:358694af-f535-48be-b7d6-ba4fba1c2fcc","http://resolver.tudelft.nl/uuid:358694af-f535-48be-b7d6-ba4fba1c2fcc","Reinforcement Learning for Orientation Estimation Using Inertial Sensors with Performance Guarantee","Hu, Liang (University of Essex); Tang, Y. (TU Delft Robot Dynamics); Zhou, Z. (TU Delft Robot Dynamics); Pan, W. (TU Delft Robot Dynamics)","","2021","This paper presents a deep reinforcement learning (DRL) algorithm for orientation estimation using inertial sensors combined with a magnetometer. Lyapunov’s method in control theory is employed to prove the convergence of orientation estimation errors. The estimator gains and a Lyapunov function are parametrised by deep neural networks and learned from samples based on the theoretical results. The DRL estimator is compared with three well-known orientation estimation methods on both numerical simulations and real dataset collected from commercially available sensors. The results show that the proposed algorithm is superior for arbitrary estimation initialisation and can adapt to a drastic angular velocity profile for which other algorithms can be hardly applicable. To the best of our knowledge, this is the first DRL-based orientation estimation method with an estimation error boundedness guarantee.","","en","conference paper","IEEE","","","","","Accepted Author Manuscript","","","","","Robot Dynamics","","",""
"uuid:4c017a9f-22c8-49e7-8cdb-e737eb402b7e","http://resolver.tudelft.nl/uuid:4c017a9f-22c8-49e7-8cdb-e737eb402b7e","Deep Recursive Embedding for High-Dimensional Data","Zhou, Zixia (Fudan University); Zu, Xinrui (University of Twente); Wang, Yuanyuan (Fudan University); Lelieveldt, Boudewijn P.F. (Universiteit Leiden); Tao, Q. (TU Delft ImPhys/Medical Imaging)","","2021","Embedding high-dimensional data onto a low-dimensional manifold is of both theoretical and practical value. In this article, we propose to combine deep neural networks (DNN) with mathematics-guided embedding rules for high-dimensional data embedding. We introduce a generic deep embedding network (DEN) framework, which is able to learn a parametric mapping from high-dimensional space to low-dimensional space, guided by well-established objectives such as Kullback-Leibler (KL) divergence minimization. We further propose a recursive strategy, called deep recursive embedding (DRE), to make use of the latent data representations for boosted embedding performance. We exemplify the flexibility of DRE by different architectures and loss functions, and benchmarked our method against the two most popular embedding methods, namely, t-distributed stochastic neighbor embedding (t-SNE) and uniform manifold approximation and projection (UMAP). The proposed DRE method can map out-of-sample data and scale to extremely large datasets. Experiments on a range of public datasets demonstrated improved embedding performance in terms of local and global structure preservation, compared with other state-of-The-Art embedding methods. Code is available at https://github.com/tao-Aimi/DeepRecursiveEmbedding.","Data visualization; deep embedding network; deep recursive embedding; Feature extraction; Manifolds; Standards; t-distributed stochastic neighbor embedding; Tools; Training; uniform manifold approximation and projection; Unsupervised learning; unsupervised learning","en","journal article","","","","","","","","","","","ImPhys/Medical Imaging","","",""
"uuid:76a618d2-2b68-4195-adf5-f6d289dfb35d","http://resolver.tudelft.nl/uuid:76a618d2-2b68-4195-adf5-f6d289dfb35d","Comparative Assessment of Methods for Coupling Regional and Local Groundwater Flow Models: A Case Study in the Beijing Plain, China","Liu, S. (TU Delft Water Resources; IHE Delft Institute for Water Education); Zhou, Yangxiao (IHE Delft Institute for Water Education; Hebei University of Geosciences); Xie, Mingzhao (IHE Delft Institute for Water Education); McClain, M.E. (TU Delft Water Resources; IHE Delft Institute for Water Education); Wang, Xu Sheng (China University of Geosciences)","","2021","A coupled regional and local model is required when groundwater flow and solute transport are to be simulated in local areas of interest with a finer grid while regional aquifer boundary and major stresses should be retained with a coarser grid. The coupled model should also maintain interactions between the regional and local flow systems. In the Beijing Plain (China), assessment of managed aquifer recharge (MAR), groundwater pollution caused by rivers, capture zone of well fields, and land subsidence at the cone of depression requires a coupled regional and local model. This study evaluates three methods for coupling regional and local flow models for simulating MAR in the Chaobai River catchment in the Beijing Plain. These methods are the conventional grid refinement (CGR) method, the local grid refinement (LGR) method and the unstructured grid (USG) method. The assessment included the comparison of the complexity of the coupled model construction, the goodness of fit of the computed and observed groundwater heads, the consistency of regional and local groundwater budgets, and the capture zone of a well filed influenced by the MAR site. The results indicated that the CGR method based on MODFLOW-2005 is the easiest to implement the coupled model, capable of reproducing regional and local groundwater heads and budget, and already coupled with density and viscosity dependent model codes for transport simulation. However, the CGR method inherits shortcomings of finite difference grids to create multiple local models with inefficient computing efforts. The USG method based on MODFLOW-USG has the advantage of creating multi-scale models and is flexible to simulate rivers, wells, irregular boundaries, heterogeneities and the MAR site. However, it is more difficult to construct the coupled models with the unstructured grids, therefore, a good graphic user interface is necessary for efficient model construction. The LGR method based on MODFLOW-LGR can be used to create multiple local models in uniform aquifer systems. So far, little effort has been devoted to upgrade the LGR method for complex aquifer structures and develop the coupled transport models.","Grid refinement; Groundwater modeling; Multi-scale model","en","journal article","","","","","","","","","","","Water Resources","","",""
"uuid:1945fee8-10da-4ad4-ab52-411faa3684da","http://resolver.tudelft.nl/uuid:1945fee8-10da-4ad4-ab52-411faa3684da","An experimental and theoretical investigation of the effect of second-phase particles on grain growth during the annealing of hot-rolled AZ61 magnesium alloy","Mohseni, M. (Iran University of Science and Technology); Eivani, A.R. (Iran University of Science and Technology); Vafaeenezhad, H. (Iran University of Science and Technology); Jafarian, H. R. (Iran University of Science and Technology); Salehi, M. T. (Iran University of Science and Technology); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2021","The mechanical properties of a magnesium alloy strongly depend on its grain structure. It is desirable to minimize grain growth during the post-forming annealing treatment, thereby minimizing the loss in strength while regaining ductility. In the present research, the annealing of the hot-rolled AZ61 Mg alloy at different temperatures for different times was performed to reveal the kinetics of grain growth, as affected by the precipitation or dissolution of second-phase particles. Three approaches, i.e., experimental, analytical modeling and atomistic simulation were taken and the results were compared. The predictions made from the analytical model and Monte Carlo simulation were both in acceptable agreement with experimental results in terms of the resultant grain sizes. However, the Monte Carlo simulation showed advantages over the analytical model. It was found that with increasing annealing temperature and holding time, the fraction of second-phase particles reduced, which strongly affected the kinetics of grain growth, limiting grain size and grain size homogeneity. The average grain sizes and the largest grain sizes were both taken as the characteristic parameters of the as-annealed microstructure. The results pointed out the importance of choosing an appropriate combination of annealing temperature and time in order to retain second-phase particles during annealing not only for preventing unrestricted grain growth but also for avoiding grain size inhomogeneity.","Analytical model; Annealing; Grain growth; Hot rolling; Magnesium; Monte Carlo; Recrystallization","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:29069771-fe02-4ced-9910-ba8670ffa88e","http://resolver.tudelft.nl/uuid:29069771-fe02-4ced-9910-ba8670ffa88e","Coordination Control of Power Flow Controller and Hybrid DC Circuit Breaker in MVDC Distribution Networks","Liao, Jianquan (Sichuan University); Zhou, Niancheng (Chongqing University); Qin, Z. (TU Delft DC systems, Energy conversion & Storage); Purgat, P. (TU Delft DC systems, Energy conversion & Storage); Wang, Qianggang (Chongqing University); Bauer, P. (TU Delft DC systems, Energy conversion & Storage)","","2021","The two main challenges of medium voltage direct current (MVDC) distribution network are the flexible control of power flow (PF) and fault protection. In this paper, the power flow controller (PFC) is introduced to regulate the PF and inhibit the fault current during the DC fault. The coordination strategy of series-parallel PFC (SP-PFC) and hybrid DC circuit breaker (DCCB) is proposed. By regulating the polarity and magnitude of SP-PFC output voltage during the fault, the rising speed of fault current can be suppressed so as to reduce the breaking current of hybrid DCCB. The access mode of SP-PFC to the MVDC distribution network and its topology are analyzed, and the coordination strategy between SP-PFC and hybrid DCCB is investigated. Moreover, the emergency control and bypass control strategies of SP-PFC are developed. On this basis, the mathematical model of SP-PFC in different fault stages is derived. With the equivalent model of SP-PFC, the fault current of the MVDC distribution network can be calculated accurately. A simulation model of the MVDC distribution network containing SP-PFC is established in MATLAB/Simulink. The fault current calculation result is compared with the simulation result, and the effectiveness of the proposed coordination strategy is verified.","DC circuit breaker (DCCB); Medium voltage direct current (MVDC) distribution network; fault current; power flow controller (PFC)","en","journal article","","","","","","","","","","","DC systems, Energy conversion & Storage","","",""
"uuid:7e39bbc2-46f3-43f0-a580-964cd5e733ce","http://resolver.tudelft.nl/uuid:7e39bbc2-46f3-43f0-a580-964cd5e733ce","A Comprehensive Workflow for High Resolution 3D Solar Photovoltaic Potential Mapping in Dense Urban Environment: A Case Study on Campus of Delft University of Technology","Zhou, Y. (TU Delft Photovoltaic Materials and Devices); Verkou, M.H. (TU Delft Electrical Engineering, Mathematics and Computer Science); Zeman, M. (TU Delft Electrical Sustainable Energy); Ziar, H. (TU Delft Photovoltaic Materials and Devices); Isabella, O. (TU Delft Photovoltaic Materials and Devices)","","2021","Photovoltaic (PV) technology is the most promising renewable energy source to be integrated on urban building surfaces. Modeling and simulating urban PV systems pose more challenges than the conventional ones installed in open field due to rich urban morphology. Herein, a comprehensive workflow to estimate urban solar PV potential is developed where TU Delft campus is used as a case study. This workflow only requires light detection and ranging data and building footprints as data inputs, and multiple levels of result can be delivered including accurate geo-referenced 3D building models, annual solar irradiation map, annual DC/AC yield maps and classified roof segments according to the specific yield of mounted PV system. The study reports a total of ≈8.1 GWh year−1 of PV energy which can be collected from campus building roofs and facades. Given the total electricity demand on the entire campus being 82.6 GWh/year, this PV potential can cover roughly 10% of the current electricity demand. The results constitute an initial assessment of solar PV potential on TU Delft campus buildings that is currently being used to prioritize PV integration on buildings and accelerate the transition toward a climate-neutral campus.","building integrated PV; complex geometry; electrical energy yield simulation; modeling; photovoltaic potential; solar mapping; urban PV","en","journal article","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Electrical Sustainable Energy","Photovoltaic Materials and Devices","","",""
"uuid:99cef9ea-7bd5-4299-ae62-28423403a05a","http://resolver.tudelft.nl/uuid:99cef9ea-7bd5-4299-ae62-28423403a05a","Delft University of Technology - Campus PV potential, analysis report","Fremouw, M.A. (TU Delft Environmental & Climate Design); Zhou, Y. (TU Delft Photovoltaic Materials and Devices); Puji Nata Djaja, P.N.","","2021","","","en","report","Delft University of Technology","","","","","","","","","","Environmental & Climate Design","","",""
"uuid:00919884-e74a-41a2-a9d6-7c4af7ee11e5","http://resolver.tudelft.nl/uuid:00919884-e74a-41a2-a9d6-7c4af7ee11e5","Muntonderzoek op microschaal","Huisman, H (External organisation); van Eijck, L. (TU Delft RST/Neutron and Positron Methods in Materials); Ngan-Tillard, D.J.M. (TU Delft Geo-engineering); Joosten, I.A.E. (Student TU Delft); Zhou, Z. (TU Delft RST/Neutron and Positron Methods in Materials)","de Groot, T (editor); de Kort, J.W. (editor)","2021","","","nl","book chapter","","","","","","","","","","","RST/Neutron and Positron Methods in Materials","","",""
"uuid:2496cbf2-0b8a-43cf-9cc4-251c0d968f57","http://resolver.tudelft.nl/uuid:2496cbf2-0b8a-43cf-9cc4-251c0d968f57","Erratum: Plane-wave orthogonal polynomial transform for amplitude-preserving noise attenuation (Geophysical Journal International (2018) 214 (ggy267) DOI: 10.1093/gji/ggy267)","Chen, Yangkang (Zhejiang University); Huang, Weilin (China University of Petroleum - Beijing); Zhou, Yatong (Hebei University of Technology); Liu, Wei (China University of Petroleum - Beijing); Zhang, D. (TU Delft ImPhys/Medical Imaging; TU Delft ImPhys/Computational Imaging)","","2021","The journal is publishing this Expression of Concern to alert readers while we investigate to determine whether further action is required.","","en","journal article","","","","","","","","","","","ImPhys/Medical Imaging","","",""
"uuid:7b69b5ac-4599-4150-994e-631a54742cc8","http://resolver.tudelft.nl/uuid:7b69b5ac-4599-4150-994e-631a54742cc8","LaSeSOM: A Latent and Semantic Representation Framework for Soft Object Manipulation","Zhou, Peng (The Hong Kong Polytechnic University); Zhu, J. (TU Delft Learning & Autonomous Control); Huo, Shengzeng (The Hong Kong Polytechnic University); Navarro-Alarcon, David (The Hong Kong Polytechnic University)","","2021","Soft object manipulation has recently gained popularity within the robotics community due to its potential applications in many economically important areas. Although great progress has been recently achieved in these types of tasks, most state-of-the-art methods are case-specific; They can only be used to perform a single deformation task (e.g. bending), as their shape representation algorithms typically rely on ""hard-coded"" features. In this paper, we present LaSeSOM, a new feedback latent representation framework for semantic soft object manipulation. Our new method introduces internal latent representation layers between low-level geometric feature extraction and high-level semantic shape analysis; This allows the identification of each compressed semantic function and the formation of a valid shape classifier from different feature extraction levels. The proposed latent framework makes soft object representation more generic (independent from the object's geometry and its mechanical properties) and scalable (it can work with 1D/2D/3D tasks). Its high-level semantic layer enables to perform (quasi) shape planning tasks with soft objects, a valuable and underexplored capability in many soft manipulation tasks. To validate this new methodology, we report a detailed experimental study with robotic manipulators.","Bimanual Manipulation; Geodesic Interpolation; Latent Space and Manifolds; Manifolds; Planning; Representation Learning; Semantics; Shape; Shape Deformation Planning; Strain; Task analysis; Three-dimensional displays","en","journal article","","","","","","Accepted Author Manuscript","","","","","Learning & Autonomous Control","","",""
"uuid:36feb185-cca3-4bdf-8a36-f9bbf2344508","http://resolver.tudelft.nl/uuid:36feb185-cca3-4bdf-8a36-f9bbf2344508","Neutron tomography of Van Leeuwenhoek's microscopes","Cocquyt, Tiemen (Rijksmuseum Boerhave); Zhou, Z. (TU Delft RST/Neutron and Positron Methods in Materials); Plomp, J. (TU Delft RID/TS/Instrumenten groep); van Eijck, L. (TU Delft RST/Neutron and Positron Methods in Materials)","","2021","The technique of neutron tomography has, after 350 years, enabled a first look inside the iconic single-lens microscopes of Antoni van Leeuwenhoek. Van Leeuwenhoek's 17th-century discovery of ""animalcules""marks the birth of microbiology. His skillfully self-produced microscope lenses remained unsurpassed for over 150 years. Neutron tomography now enabled us to reveal the lens types Van Leeuwenhoek used. We argue that Van Leeuwenhoek's instruments incorporate some innovations that testify to an awareness of concurrent developments. In particular, our analysis shows that for making his best-performing microscopes, Van Leeuwenhoek deployed a lens-making procedure popularized in 1678 by Robert Hooke. This is notable, as Hooke always wanted to find the secret of Van Leeuwenhoek's lenses, but never managed to do so. Therefore, Van Leeuwenhoek was far from the isolated scholar he is often claimed to be; rather, his secrecy about his lenses was motivated by an attempt to conceal his indebtedness to Hooke.","OA-Fund TU Delft","en","journal article","","","","","","","","","","","RST/Neutron and Positron Methods in Materials","","",""
"uuid:efaee15c-2492-4420-a25a-23e9ea9248e2","http://resolver.tudelft.nl/uuid:efaee15c-2492-4420-a25a-23e9ea9248e2","The effect of addition of hardystonite on the strength, ductility and corrosion resistance of WE43 magnesium alloy","Eivani, A.R. (Iran University of Science and Technology); Tabatabaei, F. (Iran University of Science and Technology); Khavandi, A. R. (Iran University of Science and Technology); Tajabadi, M. (Iran University of Science and Technology); Mehdizade, M. (Iran University of Science and Technology); Jafarian, H. R. (Iran University of Science and Technology); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2021","A composite material based on the WE43 magnesium alloy and containing nano-sized hardystonite ceramic particles was processed by means of friction stir processing (FSP). Compressive strength and strain-at-failure of the WE43 alloy increased as a combined result of FSP and nanoparticle reinforcement. The results of potentiondynamic polarization and electrochemical impedance spectroscopy tests indicated that the corrosion mechanism of the nanocomposite is combination of uniform corrosion and localized pitting corrosion which is not different from the base metal. However, the corrosion rate is significantly decreased as a result of reduced localized corrosion of the base metal after FSP and the effect of hardystonite to reduce pitting corrosion. The polarization resistance is increased from 192.48 to 339.61 and 1318.12 Ω/cm2 by applying FSP on WE43 and addition of nano-sized hardystonite particles, respectively. Indeed, the fabricated nanocomposite shows significantly increased corrosion resistance. Enhanced strength, ductility and corrosion resistance were attributed to grain refinement in addition to the fragmentation and redistribution of second-phase particles in the magnesium matrix, occurring during FSP.","Corrosion properties; Friction stir processing; Hardystonite; Magnesium; Nanocomposite","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:4889aa60-5b6e-44ff-854a-03435661e359","http://resolver.tudelft.nl/uuid:4889aa60-5b6e-44ff-854a-03435661e359","Intelligent UAV Swarm Cooperation for Multiple Targets Tracking","Zhou, Longyu (University of Electronic Science and Technology of China); Leng, Supeng (University of Electronic Science and Technology of China); Liu, Qiang (University of Electronic Science and Technology of China; School of Information and Communication Engineering, Chengdu); Wang, Q. (TU Delft Embedded Systems)","","2021","With the advantages of easy deployment and flexible usage, Unmanned Aerial Vehicle (UAV) has advanced the Multi-Target Tracking (MTT) applications. The UAV-MTT system has great potentials to execute dull, dangerous, and critical missions for frontier defense and security. A key challenge in UAV-MTT is how to coordinate multiple UAVs to track diverse invading targets accurately and consecutively. In this paper, we propose a UAV swarm-based cooperative tracking architecture to systematically improve the UAV tracking performance. We design an intelligent UAV swarm-based cooperative algorithm for consecutive target tracking and physical collision avoidance. Moreover, we design an efficient cooperative algorithm to predict the trajectory of invading targets accurately. Our simulation results demonstrate that the swarm behaviors stay stable in realistic scenarios with perturbing obstacles. Compared with state-of-the-art solutions such as the matched deep Q-network, our algorithms can increase tracking accuracy by 60%, reduce tracking delay by 23%, and achieve physical collision-avoidance during the tracking process.","Mobile target tracking; prediction; scheduling; unmanned-aerial-vehicle (UAV) swarm intelligence (SI)","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-01-13","","","Embedded Systems","","",""
"uuid:d6ebc36a-bd51-4ada-8afc-5dcdeb66d9ac","http://resolver.tudelft.nl/uuid:d6ebc36a-bd51-4ada-8afc-5dcdeb66d9ac","Erratum: The inactivation mechanism of chemical disinfection against SARS-CoV-2: The MD and DFT perspectives(RSC Advances (2020) 10 (40480–40488) DOI: 10.1039/D0RA06730J)","Tan, C. (TU Delft Electronic Components, Technology and Materials; Southern University of Science and Technology; Shenzhen Institute of Wide-bandgap Semiconductors); Gao, Chenshan (Chongqing University); Zhou, Quan (Chongqing University); van Driel, W.D. (TU Delft Electronic Components, Technology and Materials; Signify); Ye, H. (Shenzhen Institute of Wide-bandgap Semiconductors; Ministry of Education, Shenzhen; Southern University of Science and Technology); Zhang, Kouchi (TU Delft Electronic Components, Technology and Materials)","","2021","The authors regret that one of the affiliations (affiliation f) was incorrectly omitted in the original manuscript. The corrected list of affiliations is as shown below. The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.","","en","journal article","","","","","","","","","","","Electronic Components, Technology and Materials","","",""
"uuid:cdf239b2-bda3-4626-b916-15e3fcd17fa1","http://resolver.tudelft.nl/uuid:cdf239b2-bda3-4626-b916-15e3fcd17fa1","DFT and experimental study of elemental mercury (Hg0) removal by 2D-g-C3N4","Liu, G. (TU Delft Sanitary Engineering; Jiangnan University); Yan, Qun (Jiangnan University); Zhou, Yanan (Sichuan University); Zhang, X. (TU Delft Sanitary Engineering); Spanjers, H. (TU Delft Sanitary Engineering)","","2021","2D-g-C3N4 nanosheet was prepared and employed for the adsorption of elemental mercury (Hg0). The g-C3N4 was analyzed through X-ray diffraction (XRD), scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR) methods, and the results showed that the prepared sample was well-defined 2D-nanosheet. The 2D-g-C3N4 sorbent exhibited a high Hg0 removal efficiency (> 90%) at the condition of temperature 120 °C. To investigate the mechanism of Hg0 adsorption on the 2D-g-C3N4 surface, corresponding theoretical exploration based on the first principle prediction and X-ray photoelectron spectroscopy (XPS) test was implemented. The DFT calculation results showed that Hg0 was strongly bound to the B1 site of the g-C3N4 surface with an adsorption energy change of -162.2 kJ mol−1, the equilibrium distance of Hg-C was 3.473 Å, and electron transfer between Hg and C atoms was 0.02. The results of XPS showed the main species of mercury was HgO on the surface of 2D-g-C3N4 sample and the interaction between C3N4 surface and Hg0 was physisorption. This study provides a demonstration of proof-of-concept demonstration that g-C3N4 is a promising sorbent capable of capturing Hg0, and presents in-depth understanding of Hg0 adsorption mechanism on 2D-g-C3N4 sorbent.","Adsorption; CN; DFT; Elemental mercury","en","journal article","","","","","","","","","","","Sanitary Engineering","","",""
"uuid:e6a8c4b3-c5a5-4ff4-bb8b-6870c9528608","http://resolver.tudelft.nl/uuid:e6a8c4b3-c5a5-4ff4-bb8b-6870c9528608","High-Silica CHA Zeolite Membrane with Ultra-High Selectivity and Irradiation Stability for Krypton/Xenon Separation","Wang, Xuerui (Nanjing Tech University); Zhou, Tao (Nanjing Tech University); Zhang, Ping (Nanjing Tech University); Yan, Wenfu (Jilin University); Li, Yongguo (China Institute for Radiation, Taiyuan); Peng, Li (Nanjing Tech University); Veerman, Dylan (Student TU Delft); Shi, Mengyang (Nanjing Tech University); Gu, Xuehong (Nanjing Tech University); Kapteijn, F. (TU Delft ChemE/Catalysis Engineering)","","2021","Capture and storage of the long-lived 85Kr is an efficient approach to mitigate the emission of volatile radionuclides from the spent nuclear fuel reprocessing facilities. However, it is challenging to separate krypton (Kr) from xenon (Xe) because of the chemical inertness and similar physical properties. Herein we prepared high-silica CHA zeolite membranes with ultra-high selectivity and irradiation stability for Kr/Xe separation. The suitable aperture size and rigid framework endures the membrane a strong size-exclusion effect. The ultrahigh selectivity of 51–152 together with the Kr permeance of 0.7–1.3×10−8 mol m−2 s−1 Pa−1 of high-silica CHA zeolite membranes far surpass the state-of-the-art polymeric membranes. The membrane is among the most stable polycrystalline membranes for separation of humid Kr/Xe mixtures. Together with the excellent irradiation stability, high-silica CHA zeolite membranes pave the way to separate radioactive Kr from Xe for a notable reduction of the volatile nuclear waste storage volume.","CHA zeolite; gas separation; krypton; membrane; xenon","en","journal article","","","","","","","","","","","ChemE/Catalysis Engineering","","",""
"uuid:602e1728-f7fe-4d6e-a23d-93457277a964","http://resolver.tudelft.nl/uuid:602e1728-f7fe-4d6e-a23d-93457277a964","Improving the Mechanical Properties of Additively Manufactured Micro-Architected Biodegradable Metals","Li, Yageng (University of Science and Technology Beijing); Shi, Jirong (Peking University); Jahr, H. (Medizinische Fakultat und Universitats Klinikum Aachen; Maastricht UMC); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics); Wang, Luning (University of Science and Technology Beijing)","","2021","Additively manufactured (AM) micro-architected biodegradable metals offer a unique combination of properties that are ideal for bone regeneration including biocompatibility, a fully interconnected porous structure, and the possibility to fully regenerate bony defects with native tissue upon biodegradation. Currently, the mechanical properties of AM biodegradable porous metals can only match the values of human trabecular bone, hindering their applications for cortical bone regeneration. So far, different approaches have been applied to improve the mechanical properties of AM biodegradable porous metals. Here, we present the state-of-the-art in AM biodegradable porous metals with a focus on the effects of material composition, geometrical design, AM process, and post-AM treatments on their mechanical properties. We also identify a number of challenges encountered in adopting AM biodegradable porous metals for orthopedic applications from the mechanical viewpoint and suggest some promising areas for future research.","","en","review","","","","","","Accepted Author Manuscript","","2022-10-25","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:9a31df1d-0195-4b25-acd0-c5683808f611","http://resolver.tudelft.nl/uuid:9a31df1d-0195-4b25-acd0-c5683808f611","Improved iGAL 2.0 Metric Empowers Pharmaceutical Scientists to Make Meaningful Contributions to United Nations Sustainable Development Goal 12","Roschangar, Frank (Boehringer Ingelheim Pharma GmbH and Co. KG); Li, Jun (Bristol-Myers Squibb); Zhou, Yanyan (California State University East Bay); Aelterman, Wim (Janssen Pharmaceutica Campus); Borovika, Alina (Bristol-Myers Squibb); Colberg, Juan (Pfizer Inc.); Dickson, David P. (Teva Pharmaceuticals); Gallou, Fabrice (Novartis Pharma); Sheldon, R.A. (TU Delft BT/Biocatalysis; University of Witwatersrand)","","2021","The large and steadily growing demand for medicines combined with their inherent resource-intensive manufacturing necessitates a relentless push for their sustainable production. Pharmaceutical companies are constantly seeking to perform reliable life cycle assessments of their medicinal products and assess the true value of their sustainable development achievements; however, they find themselves impeded by the lack of a universal metric system that allows for objective quantification of the underlying core denominators. Guided by the unambivalent purpose of the United Nations Sustainable Development Goal 12, which aims at substantially reducing production waste by 2030, and driven by a vision to catalyze greener active pharmaceutical ingredient (API) manufacturing around the globe, the authors set out to overcome current obstacles by defining an improved model for the metric named innovation green aspiration level, iGAL 2.0. We propose yield and convergence as new key sustainability indicators and include a new formula for convergence with potential applicability in computer assisted synthesis planning (CASP) algorithms. The improved statistical model of iGAL 2.0 represents a valuable extension to the common API process waste metrics, process mass intensity (PMI) and complete E factor (cEF), by putting those measures into perspective: iGAL 2.0 enables determination of relative process greenness (RPG) to identify potentially underperforming and environmentally concerning processes early and thereby deliver environmental value. At the same time, iGAL 2.0 generates economic value since reduced waste correlates to lower API production costs. The metric is complemented by its scorecard companion to highlight the impact of innovation on reductions of API manufacturing waste, enabling scientists to readily communicate the value of their work to their peers, managers, and the general public. We believe that iGAL 2.0 can readily be adopted by pharmaceutical firms around the globe and thereby empower and inspire their scientists to make meaningful and significant contributions to global sustainability.","Active pharmaceutical ingredient (API); Complete E factor (cEF); Computer assisted synthesis planning (CASP); Convergence; Green chemistry metrics; Innovation green aspiration level (iGAL); Life cycle assessment (LCA); Relative process greenness (RPG); Scorecard; United Nations Sustainable Development Goal (UN SDG)","en","journal article","","","","","","","","","","","BT/Biocatalysis","","",""
"uuid:f93be540-8009-48e2-86b3-24ffc60a51c4","http://resolver.tudelft.nl/uuid:f93be540-8009-48e2-86b3-24ffc60a51c4","Digital biofabrication to realize the potentials of plant roots for product design","Zhou, J. (TU Delft Emerging Materials); Barati, Bahareh (Student TU Delft); Wu, J. (TU Delft Materials and Manufacturing); Scherer, Diana (External organisation); Karana, E. (TU Delft Emerging Materials)","","2021","Technological and economic opportunities, alongside the apparent ecological benefits, point to biodesign as a new industrial paradigm for the fabrication of products in the twenty-first century. The presented work studies plant roots as a biodesign material in the fabrication of self-supported 3D structures, where the biologically and digitally designed materials provide each other with structural stability. Taking a material-driven design approach, we present our systematic tinkering activities with plant roots to better understand and anticipate their responsive behaviour. These helped us to identify the key design parameters and advance the unique potential of plant roots to bind discrete porous structures. We illustrate this binding potential of plant roots with a hybrid 3D object, for which plant roots connect 600 computationally designed, optimized, and fabricated bioplastic beads into a low stool.","Biodesign; Digital biofabrication; Living organisms; Material-driven design; Plant roots","en","journal article","","","","","","","","","","","Emerging Materials","","",""
"uuid:c52674a9-bdc0-4508-86cb-fee8bc8d3c05","http://resolver.tudelft.nl/uuid:c52674a9-bdc0-4508-86cb-fee8bc8d3c05","Bridge Load Testing: State-of-The-Practice","Alampalli, Sreenivas (LLC); Frangopol, Dan M. (Lehigh University); Grimson, Jesse (Bdi); Halling, Marvin W. (Utah State University); Kosnik, David E. (CTL Group); Lantsoght, E.O.L. (TU Delft Concrete Structures); Yang, David (Portland State University); Zhou, Y. Edward (Aecom)","","2021","Bridge load testing can answer a variety of questions about bridge behavior that cannot be answered otherwise. The current governing codes and guidelines for bridge load testing in the United States are the 1998 NCHRP Manual for Bridge Rating through Load Testing and Chapter 8 of the AASHTO Manual for Bridge Evaluation. Over the last two decades, the practice of load testing has evolved, and its intersections with other fields have expanded. The outcomes of load tests have been used to keep bridges open cost-effectively without unnecessarily restricting legal loads, when theoretical analyses cannot yield insights representative of in-service performance. Load testing data can be further used to develop field-verified finite-element models of tested bridges to understand these structures better. In addition, structural reliability concepts can be used to estimate the probability of failure based on the results of load tests, and noncontact measurement techniques capturing large surfaces of bridges allow for better monitoring of structural responses. Given these developments, a new Transportation Research Board (TRB) Circular, Primer on Bridge Load Testing, has been developed. This document contains new proposals for interpreting the results of diagnostic load tests, loading protocols, and the determination of bridge load ratings based on the results of proof load tests. In addition, included provisions provide an estimation of the resulting reliability index and the remaining service life of a bridge based on load testing results. The benefit of load testing is illustrated based on a cost-benefit analysis. The current state-of-The-practice has demonstrated that load testing is an effective means for answering many important questions regarding bridge behavior that are critical to decisions on bridge maintenance or replacement. Load testing has evolved over its history, and the newly developed TRB Circular reflects this evolution in a practical way.","Bridge maintenance; Bridge tests; Codes and guidelines; Field tests; Instrumentation; Load testing","en","review","","","","","","Accepted Author Manuscript","","","","","Concrete Structures","","",""
"uuid:513ef88e-bd9f-4ec1-a46c-9c3ab4829eb1","http://resolver.tudelft.nl/uuid:513ef88e-bd9f-4ec1-a46c-9c3ab4829eb1","A novel approach to determine residual stress field during FSW of AZ91 Mg alloy using combined smoothed particle hydrodynamics/neuro-fuzzy computations and ultrasonic testing","Eivani, A.R. (Iran University of Science and Technology); Vafaeenezhad, H. (Iran University of Science and Technology); Jafarian, H. R. (Iran University of Science and Technology); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2021","The faults in welding design and process every so often yield defective parts during friction stir welding (FSW). The development of numerical approaches including the finite element method (FEM) provides a way to draw a process paradigm before any physical implementation. It is not practical to simulate all possible designs to identify the optimal FSW practice due to the inefficiency associated with concurrent modeling of material flow and heat dissipation throughout the FSW. This study intends to develop a computational workflow based on the mesh-free FEM framework named smoothed particle hydrodynamics (SPH) which was integrated with adaptive neuro-fuzzy inference system (ANFIS) to evaluate the residual stress in the FSW process. An integrated SPH and ANFIS methodology was established and the well-trained ANIS was then used to predict how the FSW process depends on its parameters. To verify the SPH calculation, an itemized FSW case was performed on AZ91 Mg alloy and the induced residual stress was measured by ultrasonic testing. The suggested methodology can efficiently predict the residual stress distribution throughout friction stir welding of AZ91 alloy.","Adaptive neuro-fuzzy inference system (ANFIS); Friction stir welding (FSW); Residual stress; Smoothed particle hydrodynamics (SPH); Ultrasonic","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:403f7fa2-9f24-4b32-8748-22c3fabea0ea","http://resolver.tudelft.nl/uuid:403f7fa2-9f24-4b32-8748-22c3fabea0ea","Additively Manufactured Absorbable Porous Metal Implants: Processing, Alloying and Corrosion Behavior","Jahr, H. (TU Delft Biomaterials & Tissue Biomechanics; Maastricht UMC); Li, Y. (University of Science and Technology Beijing); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics); Schröder, AKi-Uwe (Rheinisch-Westfälische Technische Hochschule)","","2021","Treating large bone defects is still a clinical challenge without perfect solution, mainly due to the unavailability of suitable bone implants. Additively manufactured (AM) absorbable porous metals provide unparalleled opportunities to realize the challenging requirements for bone-mimetic implants. Firstly, multi-scale geometries of such implants can be customized to mimic the micro-architecture and mechanical properties of human bone. The interconnected porous structure additionally increases the surface area to facilitate adhesion and proliferation of bone cells. Finally, their absorption properties are tunable to maintain the structural integrity of the implant throughout the bone healing process, ensuring sufficient loadbearing when needed and full disintegration after their job is done. Such a combination of properties paves the way for complete bone regeneration and remodeling. It is important to thoroughly characterize the biodegradation behavior, mechanical properties, and bone regeneration ability when developing ideal porous absorbable metal implants. We review the state-of-the-art of absorbable porous metals manufactured by selective laser melting (SLM), with a focus on geometrical design, material type, processing, and post-treatment. The impact of the latter aspects on absorption behavior, resulting mechanical properties, and cytocompatibility will also be briefly discussed. In comparison to their solid inert counterparts, AM absorbable porous metals (APMs) have shown many unique properties and hold tremendous potential to further optimize their application-specific performance due to their flexible geometrical design. We further highlight challenges in adopting AM APMs for future Orthopedic solutions.","selective laser melting; absorbable implants; structure; corrosion; biomechanics","en","review","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:99b3058d-2fbc-4a96-ab98-618241002e95","http://resolver.tudelft.nl/uuid:99b3058d-2fbc-4a96-ab98-618241002e95","Corrected method for scaling the dynamic response of stiffened plate subjected to blast load","Kong, Xiangshao (Wuhan University of Technology; University of Liverpool); Zhou, Hu (Wuhan University of Technology); Kuang, Zheng (Wuhan University of Technology); Zheng, Cheng (Wuhan University of Technology); Li, X. (TU Delft Marine and Transport Technology); Wu, Weiguo (Wuhan University of Technology); Guan, Zhongwei (University of Liverpool)","","2021","Test on a small scaled model is an effective approach to predict the dynamic response of full scale structure under blast loadings. However, the geometric dimensions of specimens cannot simply comply with complete geometrical similarity due to manufacture or test restrictions. It would result in the difference structural performance between the full and small scaled models. This paper proposed a corrected similarity relationship of the dynamic behaviour between prototype and replica of stiffened plates subjected to blast load, in which both the thickness of the plate and the configuration (cross-sectional shape) of stiffeners are distortedly scaled-down (double distorted geometric scaling factors). Firstly, based on the mesh convergence study and comparing with results from experimental tests, a numerical method in predicting the confined blast load and dynamic response of structure was verified, which provides a reliable means to determine the dynamic behaviour of stiffened plate designed by the corrected similarity criterion of this paper. Then, the influence of altering the stiffener configuration on the dynamic response of stiffened plates was analysed and on the basis of it, a criterion for scaling the stiffener is proposed to help design a stiffener-distorted model from prototype structure. In addition, a method for scaling the double-parameter distortedly small scaled model is proposed to predict the dynamic response of the prototype. Finally, two sets of examples of both the small size and prototype stiffened structures subjected to blast load were analysed by using the presented method. It is shown that the replica developed by applying the present method is able to accurately predict the behaviour of the full-size stiffened plates, even when the thickness of the plate and the configuration of the stiffeners are distortedly scaling down with different factors.","Confined blast load; Corrected similarity relationship; Double geometric parameters distortion; Dynamic response; Numerical simulation; Stiffened plate","en","journal article","","","","","","Accepted Author Manuscript","","2022-01-18","","Marine and Transport Technology","","","",""
"uuid:a88a4d6b-b170-437e-be1a-e7d52f76b26c","http://resolver.tudelft.nl/uuid:a88a4d6b-b170-437e-be1a-e7d52f76b26c","Beyond Solid Solution High-Entropy Alloys: Tailoring Magnetic Properties via Spinodal Decomposition","Rao, Ziyuan (Max-Planck-Institut für Eisenforschung); Dutta, B. (TU Delft (OLD) MSE-7); Körmann, F.H.W. (TU Delft (OLD) MSE-7; Max-Planck-Institut für Eisenforschung); Lu, Wenjun (Max-Planck-Institut für Eisenforschung; Southern University of Science and Technology); Zhou, Xuyang (Max-Planck-Institut für Eisenforschung); Liu, Chang (Max-Planck-Institut für Eisenforschung); da Silva, Alisson Kwiatkowski (Max-Planck-Institut für Eisenforschung); Wiedwald, Ulf (Universität Duisburg-Essen); Spasova, Marina (Universität Duisburg-Essen); Farle, Michael (Universität Duisburg-Essen); Ponge, Dirk (Max-Planck-Institut für Eisenforschung); Gault, Baptiste (Max-Planck-Institut für Eisenforschung; Imperial College London); Neugebauer, Jörg (Max-Planck-Institut für Eisenforschung); Raabe, Dierk (Max-Planck-Institut für Eisenforschung); Li, Zhiming (Max-Planck-Institut für Eisenforschung; Central South University China)","","2021","Since its first emergence in 2004, the high-entropy alloy (HEA) concept has aimed at stabilizing single- or dual-phase multi-element solid solutions through high mixing entropy. Here, this strategy is changed and renders such massive solid solutions metastable, to trigger spinodal decomposition for improving the alloys’ magnetic properties. The motivation for starting from a HEA for this approach is to provide the chemical degrees of freedom required to tailor spinodal behavior using multiple components. The key idea is to form Fe-Co enriched regions which have an expanded volume (relative to unconstrained Fe-Co), due to coherency constraints imposed by the surrounding HEA matrix. As demonstrated by theory and experiments, this leads to improved magnetic properties of the decomposed alloy relative to the original solid solution matrix. In a prototype magnetic FeCoNiMnCu HEA, it is shown that the modulated structures, achieved by spinodal decomposition, lead to an increase of the Curie temperature by 48% and a simultaneous increase of magnetization by 70% at ambient temperature as compared to the homogenized single-phase reference alloy. The findings thus open a pathway for the development of advanced functional HEAs.","coherency constraints; density functional theory; high-entropy alloys; magnetic properties; spinodal decomposition","en","journal article","","","","","","","","","","","(OLD) MSE-7","","",""
"uuid:f89d5beb-bc72-4857-a9e8-bad6549bf979","http://resolver.tudelft.nl/uuid:f89d5beb-bc72-4857-a9e8-bad6549bf979","Extrusion-based 3D printed biodegradable porous iron","Putra, N.E. (TU Delft Biomaterials & Tissue Biomechanics); Leeflang, M.A. (TU Delft Biomaterials & Tissue Biomechanics); Minneboo, M.B. (TU Delft Biomaterials & Tissue Biomechanics); Taheri, P. (TU Delft Team Peyman Taheri); Fratila-Apachitei, E.L. (TU Delft Biomaterials & Tissue Biomechanics); Mol, J.M.C. (TU Delft Team Arjan Mol); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2021","Extrusion-based 3D printing followed by debinding and sintering is a powerful approach that allows for the fabrication of porous scaffolds from materials (or material combinations) that are otherwise very challenging to process using other additive manufacturing techniques. Iron is one of the materials that have been recently shown to be amenable to processing using this approach. Indeed, a fully interconnected porous design has the potential of resolving the fundamental issue regarding bulk iron, namely a very low rate of biodegradation. However, no extensive evaluation of the biodegradation behavior and properties of porous iron scaffolds made by extrusion-based 3D printing has been reported. Therefore, the in vitro biodegradation behavior, electrochemical response, evolution of mechanical properties along with biodegradation, and responses of an osteoblastic cell line to the 3D printed iron scaffolds were studied. An ink formulation, as well as matching 3D printing, debinding and sintering conditions, was developed to create iron scaffolds with a porosity of 67%, a pore interconnectivity of 96%, and a strut density of 89% after sintering. X-ray diffracometry confirmed the presence of the α-iron phase in the scaffolds without any residuals from the rest of the ink. Owing to the presence of geometrically designed macropores and random micropores in the struts, the in vitro corrosion rate of the scaffolds was much improved as compared to the bulk counterpart, with 7% mass loss after 28 days. The mechanical properties of the scaffolds remained in the range of those of trabecular bone despite 28 days of in vitro biodegradation. The direct culture of MC3T3-E1 preosteoblasts on the scaffolds led to a substantial reduction in living cell count, caused by a high concentration of iron ions, as revealed by the indirect assays. On the other hand, the ability of the cells to spread and form filopodia indicated the cytocompatibility of the corrosion products. Taken together, this study shows the great potential of extrusion-based 3D printed porous iron to be further developed as a biodegradable bone substituting biomaterial.","3D printing; Biodegradable; Bone substitution; Iron; Material extrusion; Scaffold","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2021-05-20","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:3e5ee25c-a945-471c-bb4f-f8ec459687de","http://resolver.tudelft.nl/uuid:3e5ee25c-a945-471c-bb4f-f8ec459687de","Online label aggregation: A variational bayesian approach","Hong, C. (TU Delft Data-Intensive Systems); Ghiassi, S. (TU Delft Data-Intensive Systems); Zhou, Yichi (Tsinghua University); Birke, Robert (ABB Switzerland Ltd.); Chen, Lydia Y. (TU Delft Data-Intensive Systems)","","2021","Noisy labeled data is more a norm than a rarity for crowd sourced contents. It is effective to distill noise and infer correct labels through aggregating results from crowd workers. To ensure the time relevance and overcome slow responses of workers, online label aggregation is increasingly requested, calling for solutions that can incrementally infer true label distribution via subsets of data items. In this paper, we propose a novel online label aggregation framework, BiLA , which employs variational Bayesian inference method and designs a novel stochastic optimization scheme for incremental training. BiLA is flexible to accommodate any generating distribution of labels by the exact computation of its posterior distribution. We also derive the convergence bound of the proposed optimizer. We compare BiLA with the state of the art based on minimax entropy, neural networks and expectation maximization algorithms, on synthetic and real-world data sets. Our evaluation results on various online scenarios show that BiLA can effectively infer the true labels, with an error rate reduction of at least 10 to 1.5 percent points for synthetic and real-world datasets, respectively.","Convergence bound; Label aggregation; Online; Stochastic optimizer; Variational bayesian inference","en","conference paper","Association for Computing Machinery (ACM)","","","","","","","","","","Data-Intensive Systems","","",""
"uuid:9aeb33b8-3cd9-48a4-b591-b7cd3b407177","http://resolver.tudelft.nl/uuid:9aeb33b8-3cd9-48a4-b591-b7cd3b407177","Glacier area and snow cover changes in the range system surrounding tarim from 2000 to 2020 using google earth engine","Zhang, Jing (Chinese Academy of Sciences; University of Chinese Academy of Sciences); Jia, Li (Chinese Academy of Sciences); Menenti, M. (TU Delft Optical and Laser Remote Sensing; Chinese Academy of Sciences); Zhou, Jie (Central China Normal University); Ren, Shaoting (Chinese Academy of Sciences)","","2021","Glacier and snow are sensitive indicators of regional climate variability. In the early 21st century, glaciers in the West Kunlun and Pamir regions showed stable or even slightly positive mass budgets, and this is anomalous in a worldwide context of glacier recession. We studied the evolution of snow cover to understand whether it could explain the evolution of glacier area. In this study, we used the thresholding of the NDSI (Normalized Difference Snow Index) retrieved with MODIS data to extract annual glacier area and snow cover. We evaluated how the glacier trends related to snow cover area in five subregions in the Tarim Basin. The uncertainty in our retrievals was assessed by comparing MODIS results with the Landsat-5 TM in 2000 and Landsat-8 OLI in 2020 glacier delineation in five subregions. The glacier area in the Tarim Basin decreased by 1.32%/a during 2000–2020. The fastest reductions were in the East Tien Shan region, while the slowest relative reduction rate was observed in the West Tien Shan and Pamir, i.e., 0.69%/a and 1.08%/a, respectively, during 2000–2020. The relative glacier stability in Pamir may be related to the westerlies weather system, which dominates climate in this region. We studied the temporal variability of snow cover on different temporal scales. The analysis of the monthly snow cover showed that permanent snow can be reliably delineated in the months from July to September. During the summer months, the sequence of multiple snowfall and snowmelt events leads to intermittent snow cover, which was the key feature applied to discriminate snow and glacier.","Climate change; Glacier area; MODIS; Snow cover; Tarim Basin","en","journal article","","","","","","","","","","","Optical and Laser Remote Sensing","","",""
"uuid:9032c70c-7390-4fbd-a997-2db77616dfc9","http://resolver.tudelft.nl/uuid:9032c70c-7390-4fbd-a997-2db77616dfc9","Quantification on fuel cell degradation and techno-economic analysis of a hydrogen-based grid-interactive residential energy sharing network with fuel-cell-powered vehicles","He, Yingdong (University of California; Hunan University); Zhou, Yuekuan (The Hong Kong Polytechnic University); Wang, Zhe (Lawrence Berkeley National Laboratory); Liu, Jia (The Hong Kong Polytechnic University); Liu, Zhengxuan (TU Delft Housing Quality and Process Innovation; Hunan University); Zhang, Guoqiang (Hunan University)","","2021","Hydrogen-based (H2-based) interactive energy networks for buildings and transportations provide novel solutions for carbon-neutrality transition, regional energy flexibility and independence on fossil fuel consumption, where vehicle fuel cells are key components for H2-electricity conversion and clean power supply. However, due to the complexity in thermodynamic working environments and frequent on/off operations, the proton exchange membrane fuel cells (PEMFCs) suffer from performance degradation, depending on cabin heat balance and power requirements, and the ignorance of the degradation may lead to the performance overestimation. In order to quantify fuel cell degradation in both daily cruise and vehicle-to-grid (V2G) interactions, this study firstly proposes a two-space cabin thermal model to quantify the ambient temperature of vehicle PEMFCs and the power supply from PEMFCs to vehicle HVAC systems. Afterwards, a stack voltage model is proposed to quantify the fuel cell degradation for multiple purposes, such as daily transportation and V2G interactions. Afterwards, the two models are coupled in a community-level based building-vehicle energy network, consisting of twenty single residential buildings, rooftop PV systems, four hydrogen vehicles (HVs), a H2 station, community-served micro power grid, local main power grid, and local H2 pipelines, located in California, U.S.A. Comparative analysis with and without fuel cell degradation is conducted to study the impact of dynamic fuel cell degradation on the energy flexibility and operating cost. Furthermore, a parametrical analysis is conducted on the integrated HV quantity and the grid feed-in tariff to reach trade-off strategies between associated fuel cell degradation costs and grid import cost savings. The results indicate that, in the proposed hydrogen-based building-vehicle energy network, the total fuel cell degradation is 3.16% per vehicle within one year, where 2.50% and 0.66% are caused by daily transportation and V2G interactions, respectively. Furthermore, in the H2-based residential community, the total fuel cell degradation cost is US$6945.2, accounting for 33.4% of the total operating cost at $20770.61. The sensitivity analysis results showed that, when the HV quantity increases to twenty, the fuel cell degradation of each HV decreases to 2.50%, whereas the total fuel cell degradation cost increases to 42.8% of the total operating cost. Last but not the least, the cost saving by V2G interactions can compensate the fuel cell degradation cost when the grid feed-in tariff is reduced by 40%. Research results can provide basic modelling tools on dynamic fuel cell degradation, in respect to vehicle power supply, vehicle HVAC and V2G interactions, together with techno-economic feasibility analysis, paving path for the development of hydrogen energy for the carbon-neutrality transition.","Cabin thermal model; Distributed hydrogen infrastructure; Fuel cell degradation; Hydrogen energy storage and economy; Solar energy; Wind turbine","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-02-23","","","Housing Quality and Process Innovation","","",""
"uuid:acb4a549-4cc7-4a12-bbec-39f97ed9ec7e","http://resolver.tudelft.nl/uuid:acb4a549-4cc7-4a12-bbec-39f97ed9ec7e","A computationally efficient thermo-mechanical model for wire arc additive manufacturing","Yang, Y. (Sun Yat-sen University; Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices); Zhou, Xin (Air Force Engineering University China); Li, Quan (Capital Aerospace Machinery Corporation Limited); Ayas, C. (TU Delft Computational Design and Mechanics)","","2021","Residual stresses and distortions are major obstacles against the more widespread application of wire arc additive manufacturing. Since the steep temperature gradients due to a moving localised heat source are inevitable in this process, accurate prediction of the thermally induced residual stresses and distortions is of paramount importance. In the present study, a computationally efficient thermo-mechanical model based on a semi-analytical thermal approach incorporating Goldak heat sources is developed for the process modelling of wire arc additive manufacturing. The semi-analytical thermal model makes use of the superposition principle, and thereby decomposes the temperature field into an analytical temperature field to account for the heat sources in a semi-infinite space and a complementary temperature field to account for the boundary conditions. Since the steep temperature gradients are captured by the analytical solution, a coarse spatial discretisation can be used for the numerical solution of the complementary Tˆ field. Thermal evolution is coupled to an elasto-plastic mechanical boundary value problem that computes the thermal stresses and distortions. The accuracy of the proposed model is evaluated extensively by comparing the thermal and mechanical predictions with the corresponding experimental measurements as well as the simulation results obtained by a non-linear transient model from the literature. A thin wall structure with a length of 500 mm and consisting of 4 layers is modelled. The peak normal stress along the deposition direction can be predicted with less than 10% error. Furthermore, the simulations show that the part distortions are very sensitive to the boundary conditions.","Computationally efficiency; Goldak heat source; Thermo-mechanical modelling; Wire arc additive manufacturing","en","journal article","","","","","","Accepted Author Manuscript","","2023-06-15","","","Computational Design and Mechanics","","",""
"uuid:dc0a1512-a7bd-4580-9777-7f51b972b424","http://resolver.tudelft.nl/uuid:dc0a1512-a7bd-4580-9777-7f51b972b424","Barrier Lypunov functions-based nonsingular fixed-time switching control for strict-feedback nonlinear dynamics with full state constraints","Zhang, Wenqian (Air Force Engineering University China); Dong, Wenhan (Air Force Engineering University China); Lv, Maolong (TU Delft Team Bart De Schutter); Liu, Zongcheng (Air Force Engineering University China; Northwestern Polytechnical University); Zhou, Yang (Air Force Engineering University China); Feng, Haoming (Air Force Engineering University China)","","2021","This work proposes a nonsingular adaptive fixed-time switching control method for a class of strict-feedback nonlinear dynamics subject to full state constraints. The peculiarity of this design lies in overcoming the singularity issue that typically appears in the existing backstepping-based fixed-time control methods caused by the iterative differentiation of fractional power terms as tracking errors approach to zero, while guaranteeing the nonviolation of full state constraints. Crucial in solving such singularity issue is to skillfully introduce a smooth switching between fractional power and integer power terms, which guarantees that fractional power term is confined within a positive interval all the time. An asymmetric time-varying barrier Lyapunov function is delicately incorporated into control design, rendering state variables to be within prescribed time-varying bounds. Besides, radial basis function neural network is employed to handle system unknown nonlinearities. It is rigorously proved that all the closed-loop signals eventually converge to small regions around origin within fixed-time. Comparative simulation results are finally given to validate the effectiveness and superiority of the proposed control strategy.","adaptive backstepping control; fixed-time stability; switching control; time-varying state constraints","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2023-07-01","","","Team Bart De Schutter","","",""
"uuid:76f4bfa9-e8e4-4c4d-8957-5d7d3be6ac1b","http://resolver.tudelft.nl/uuid:76f4bfa9-e8e4-4c4d-8957-5d7d3be6ac1b","Extrusion-based 3D printing of ex situ-alloyed highly biodegradable MRI-friendly porous iron-manganese scaffolds","Putra, N.E. (TU Delft Biomaterials & Tissue Biomechanics); Leeflang, M.A. (TU Delft Biomaterials & Tissue Biomechanics); Taheri, P. (TU Delft Team Peyman Taheri); Fratila-Apachitei, E.L. (TU Delft Biomaterials & Tissue Biomechanics); Mol, J.M.C. (TU Delft Team Arjan Mol); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2021","Additively manufactured biodegradable porous iron has been only very recently demonstrated. Two major limitations of such a biomaterial are very low biodegradability and incompatibility with magnetic resonance imaging (MRI). Here, we present a novel biomaterial that resolves both of those limitations. We used extrusion-based 3D printing to fabricate ex situ-alloyed biodegradable iron-manganese scaffolds that are non-ferromagnetic and exhibit enhanced rates of biodegradation. We developed ink formulations containing iron and 25, 30, or 35 wt% manganese powders, and debinding and sintering process to achieve Fe-Mn scaffolds with 69% porosity. The Fe25Mn scaffolds had the ε-martensite and γ-austenite phases, while the Fe30Mn and Fe35Mn scaffolds had only the γ-austenite phase. All iron-manganese alloys exhibited weakly paramagnetic behavior, confirming their potential to be used as MRI-friendly bone substitutes. The in vitro biodegradation rates of the scaffolds were very much enhanced (i.e., 4.0 to 4.6 times higher than that of porous iron), with the Fe35Mn alloy exhibiting the highest rate of biodegradation (i.e., 0.23 mm/y). While the elastic moduli and yield strengths of the scaffolds decreased over 28 days of in vitro biodegradation, those values remained in the range of cancellous bone. The culture of preosteoblasts on the porous iron-manganese scaffolds revealed that cells could develop filopodia on the scaffolds, but their viability was reduced by the effect of biodegradation. Altogether, this research marks a major breakthrough and demonstrates the great prospects of multi-material extrusion-based 3D printing to further address the remaining issues of porous iron-based materials and, eventually, develop ideal bone substitutes. Statement of significance: 3D printed porous iron biomaterials for bone substitution still encounter limitations, such as the slow biodegradation and magnetic resonance imaging incompatibility. Aiming to solve the two fundamental issues of iron, we present ex-situ alloyed porous iron-manganese scaffolds fabricated by means of multi-material extrusion-based 3D printing. Our porous iron-manganese possessed enhanced biodegradability, non-ferromagnetic property, and bone-mimicking mechanical property throughout the in vitro biodegradation period. The results demonstrated a great prospect of multi-material extrusion-based 3D printing to further address the remaining challenges of porous iron-based biomaterials to be an ideal biodegradable bone substitutes.","3D printing; Biodegradable; Bone substitution; Iron-manganese; Material extrusion; Scaffold","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:c67d432d-ea4f-4daa-a80e-eac265edb987","http://resolver.tudelft.nl/uuid:c67d432d-ea4f-4daa-a80e-eac265edb987","A magnon scattering platform","Zhou, Tony X. (Harvard University); Carmiggelt, J.J. (TU Delft QN/vanderSarlab; Harvard University; Kavli institute of nanoscience Delft); Gächter, Lisa M. (Harvard University; ETH Zürich); Esterlis, Ilya (Harvard University); Sels, Dries (New York University; Flatiron Institute, New York); Stöhr, Rainer J. (Harvard University; University of Stuttgart); Du, Chunhui (Harvard University; University of California); Fernandez, Daniel (Harvard University); Rodriguez-Nieva, Joaquin F. (Harvard University); Büttner, Felix (Massachusetts Institute of Technology); Demler, Eugene (Harvard University); Yacoby, Amir (Harvard University)","","2021","Scattering experiments have revolutionized our understanding of nature. Examples include the discovery of the nucleus [R. G. Newton, Scattering Theory of Waves and Particles (1982)], crystallography [U. Pietsch, V. Holý, T. Baumback, High-Resolution X-Ray Scattering (2004)], and the discovery of the double-helix structure of DNA [J. D. Watson, F. H. C. Crick, Nature 171, 737–738]. Scattering techniques differ by the type of particles used, the interaction these particles have with target materials, and the range of wavelengths used. Here, we demonstrate a two-dimensional table-top scattering platform for exploring magnetic properties of materials on mesoscopic length scales. Long-lived, coherent magnonic excitations are generated in a thin film of yttrium iron garnet and scattered off a magnetic target deposited on its surface. The scattered waves are then recorded using a scanning nitrogen vacancy center magnetometer that allows subwavelength imaging and operation under conditions ranging from cryogenic to ambient environment. While most scattering platforms measure only the intensity of the scattered waves, our imaging method allows for spatial determination of both amplitude and phase of the scattered waves, thereby allowing for a systematic reconstruction of the target scattering potential. Our experimental results are consistent with theoretical predictions for such a geometry and reveal several unusual features of the magnetic response of the target, including suppression near the target edges and a gradient in the direction perpendicular to the direction of surface wave propagation. Our results establish magnon scattering experiments as a platform for studying correlated many-body systems.","Scattering | condensed matter physics | quantum sensing | magnetometry magnon","en","journal article","","","","","","","","","","","QN/vanderSarlab","","",""
"uuid:4a341807-3bad-45b0-adb1-aed96bdee4b2","http://resolver.tudelft.nl/uuid:4a341807-3bad-45b0-adb1-aed96bdee4b2","Effect of ethanol concentration on methane hydrate decomposition: MD simulation insights","Sun, Xiaoliang (China University of Petroleum - Beijing); Zhou, Guanggang (China University of Petroleum - Beijing); Liu, Z. (TU Delft ChemE/Advanced Soft Matter; China University of Petroleum - Beijing); Zhu, Jianwei (China University of Petroleum - Beijing); Guo, Fengzhi (China University of Petroleum - Beijing); Chen, Junqing (China University of Petroleum - Beijing); He, Wenhao (China University of Petroleum - Beijing); Wang, Ning (China University of Petroleum - Beijing); Zhao, Ge (China University of Petroleum - Beijing); Lu, Guiwu (China University of Petroleum - Beijing)","","2021","The controllability of mining is a key factor affecting the commercial application of methane hydrates, and the addition of chemical additives can significantly accelerate the mining process. However, the effect of additive concentration on hydrate decomposition is not yet well understood. In this study, we systematically investigate the effect of ethanol concentration on the decomposition of methane hydrate under varying thermodynamic conditions using molecular dynamics (MD) simulations. To quantitatively characterize the decomposition process and mechanism of methane hydrates, the combination of angular order parameter (AOP), radial distribution function (RDF), mean square displacement (MSD), diffusion coefficients and system energy was for the first time used. The results showed that the addition of ethanol contributed to the formation of methane bubbles and accelerated the decomposition of hydrates. The mass transfer effect of ethanol molecules and the reconstruction of the hydrogen bond network of water molecules determined the stability of hydrates. From 0 to 40 mol% ethanol concentration, the hydrate decomposition increased with increasing the concentration of ethanol. Both increasing the temperature and decreasing the pressure are beneficial to the decomposition of the hydrate system. These results provide the selection of optimal ethanol concentration for the decomposition of methane hydrate and reveal its decomposition mechanism, and shed important light for the controllable production of gas hydrates.","Decomposition; Ethanol concentration; Methane hydrate; Molecular dynamics; Thermodynamics","en","journal article","","","","","","","","","","","ChemE/Advanced Soft Matter","","",""
"uuid:6275fad8-a22e-4160-86eb-b183d8713cf0","http://resolver.tudelft.nl/uuid:6275fad8-a22e-4160-86eb-b183d8713cf0","Investigation into Atomic Diffusion at the Interface During Extrusion Welding of Magnesium and Magnesium Alloys","Bai, Shengwen (Chongqing University; Tsinghua University); Fang, Gang (Tsinghua University); Jiang, Bin (Chongqing University; Chongqing Academy of Science and Technology); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2021","This research was aimed to reveal atomic diffusion across the bonding interface through the extrusion-welding experiments of dissimilar materials, namely pure magnesium and Mg–Al–Zn–RE alloy. A special tooling setup used to simulate weld seam formation during extrusion through a porthole die was designed for this model study. To deform the metal streams symmetrically and create a sound weld seam, the extrusion-welding experiments from sandwich-structured billets were carried out. Chemical analysis of diffused atoms in the welding region was performed by electron probe micro-analysis. The results confirmed that atomic diffusion indeed occurred across the interface during extrusion. The gradients in element concentration, local stresses, and hydrostatic pressure were considered to be the necessary conditions for extensive atomic diffusion to occur. Atomic diffusion was significantly enhanced by raising extrusion temperature. The analysis of the stress and hydrostatic pressure distributions in the welding region provided new insights into the mechanisms of weld seam formation during the extrusion of light metals.","","en","journal article","","","","","","Accepted Author Manuscript","","2022-07-15","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:2783d050-21f2-49ca-b7b8-ec7e8d812c83","http://resolver.tudelft.nl/uuid:2783d050-21f2-49ca-b7b8-ec7e8d812c83","Corrosion resistance and tribological behavior of ZK30 magnesium alloy coated by plasma electrolytic oxidation","da Silva Rodrigues, Joel (Universidade Federal do Rio Grande do Sul); Marasca Antonini, Leonardo (Universidade Federal do Rio Grande do Sul); da Cunha Bastos, António Alexandre (University of Aveiro); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); de Fraga Malfatti, Célia (Universidade Federal do Rio Grande do Sul)","","2021","The rapid bio-corrosion of magnesium-based alloys, the formation of hydrogen gas and, consequently, the premature loss of biomechanical functions hinder their applications as biodegradable implant materials. The corrosion becomes even accelerated, when fretting wear occurs at implant junctions, as a result of repeated disruptions of the magnesium (hydr)oxide layer formed on implant surfaces. To improve the overall performance of these materials in a bio-relevant environment, especially corrosion resistance and wear resistance, in this research, plasma electrolytic oxidation (PEO) was applied to create a coating on a magnesium alloy, ZK30. The resulting gains in corrosion resistance and wear resistance were evaluated. In vitro immersion tests in Hank's solution at 37 °C showed a reduction in hydrogen release from the PEO-treated alloy. The results obtained from applying the scanning vibrating electrode technique (SVET) indicated a decreased susceptibility of the PEO-treated alloy to localized corrosion, accounting for the improved corrosion resistance. In addition, PEO was found to change the surface topography and roughness, in addition to surface chemistry, which contributed to an increased but stable coefficient of friction and a decreased material removal rate, as revealed by the tribological tests with a ball-on-plate configuration. The results indicate an enlarged opportunity of magnesium-based materials for orthopedic applications, where friction and wear are involved, by applying PEO.","Biodegradation; Corrosion; Magnesium; PEO; Wear","en","journal article","","","","","","Accepted Author Manuscript","","2023-02-22","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:511c8164-d705-4a9c-8610-07d344aea4ba","http://resolver.tudelft.nl/uuid:511c8164-d705-4a9c-8610-07d344aea4ba","Comparison in clinical performance of surgical guides for mandibular surgery and temporomandibular joint implants fabricated by additive manufacturing techniques","Oldhoff, M. G.E. (Student TU Delft); Mirzaali, Mohammad J. (TU Delft Biomaterials & Tissue Biomechanics); Tümer, N. (TU Delft Biomaterials & Tissue Biomechanics); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2021","Additive manufacturing (AM) offers great design freedom that enables objects with desired unique and complex geometry and topology to be readily and cost-effectively fabricated. The overall benefits of AM are well known, such as increased material and resource efficiency, enhanced design and production flexibility, the ability to create porous structures and on-demand manufacturing. When AM is applied to medical devices, these benefits are naturally assumed. However, hard clinical evidence collected from clinical trials and studies seems to be lacking and, as a result, systematic assessment is yet difficult. In the present work, we have reviewed 23 studies on the clinical use of AM patient-specific surgical guides (PSGs) for the mandible surgeries (n = 17) and temporomandibular joint (TMJ) patient-specific implants (PSIs) (n = 6) with respect to expected clinical outcomes. It is concluded that the data published on these AM medical devices are often lacking in comprehensive evaluation of clinical outcomes. A complete set of clinical data, including those on time management, costs, clinical outcomes, range of motion, accuracy of the placement with respect to the pre-operative planning, and extra complications, as well as manufacturing data are needed to demonstrate the real benefits gained from applying AM to these medical devices and to satisfy regulatory requirements.","Additive manufacturing; Patient-specific implants; Surgical guides; Temporomandibular joint","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:1fb4e494-5f33-4695-88cc-e687dc961558","http://resolver.tudelft.nl/uuid:1fb4e494-5f33-4695-88cc-e687dc961558","Study of Sediment Transport in a Tidal Channel-Shoal System: Lateral Effects and Slack-Water Dynamics","Zhou, Z. (TU Delft Coastal Engineering; East China Normal University); Ge, Jianzhong (East China Normal University; Institute of Eco-Chongming (IEC)); van Maren, D.S. (TU Delft Environmental Fluid Mechanics; East China Normal University; Deltares); Wang, Zhengbing (TU Delft Coastal Engineering; Deltares); Kuai, Y. (TU Delft Coastal Engineering); Ding, Pingxing (East China Normal University)","","2021","Lateral flows redistribute sediment and influence the morphodynamics of channel-shoal systems. However, our understanding of lateral transport of suspended sediment during high and low water slack is still fairly limited, especially in engineered estuaries. Human interventions such as dike-groyne structures influence lateral exchange mechanisms. The present study aims to unravel these mechanisms in a heavily engineered, turbid channel-shoal system in the Changjiang Estuary, using a high-resolution unstructured-grid three-dimensional model and in situ observations. Analysis of model results reveals two typical transport patterns during slack-water conditions, that is, shoal-to-channel transport during low water slack and channel-to-shoal transport during high water slack. A momentum balance analysis is carried out to explain mechanisms driving the lateral transport of suspended sediment during high water slack, revealing the importance of lateral pressure gradients, Coriolis force, and the curvature-induced term. Groyne fields play a crucial role in sediment transport, especially during low water slack. A model scenario in which one groyne is removed reveals that groyne fields strongly influence lateral sediment transport. The decomposition of the sediment transport flux reveals that the turbidity maximum is shaped by a balance between seaward advection by residual flows, and landward transport by tidal pumping and gravitational circulation. Within the turbidity maximum, sediment is laterally redistributed by lateral flows during slack-water conditions, greatly influencing estuarine channel morphology.","groyne fields; lateral flow; numerical model; salinity gradient; sediment transport; slack-water dynamics","en","journal article","","","","","","","","2021-08-20","","","Coastal Engineering","","",""
"uuid:1f7d4796-c759-4b39-8894-c823a313bcf1","http://resolver.tudelft.nl/uuid:1f7d4796-c759-4b39-8894-c823a313bcf1","Transformation towards a carbon-neutral residential community with hydrogen economy and advanced energy management strategies","He, Yingdong (University of California; Hunan University); Zhou, Yuekuan (The Hong Kong University of Science and Technology); Yuan, Jing (University of California); Liu, Zhengxuan (TU Delft Housing Quality and Process Innovation; Hunan University); Wang, Zhe (Lawrence Berkeley National Laboratory); Zhang, Guoqiang (Hunan University)","","2021","Cleaner power production, distributed renewable generation, building-vehicle integration, hydrogen storage and associated infrastructures are promising for transformation towards a carbon–neutral community, whereas the academia provides limited information through integrated solutions, like intermittent renewable integration, hydrogen sharing network, smart operation on electrolyzer and fuel cell, seasonal hydrogen storage and advanced heat recovery. This study proposes a hybrid electricity-hydrogen sharing system in California, United States, with synergistic electric, thermal and hydrogen interactions, including low-rise houses, rooftop photovoltaic panels, hydrogen vehicles, a hydrogen station, micro and utility power grid and hydrogen pipelines. Advanced energy management strategies were proposed to enhance energy flexibility and grid stability. Besides, simulation-based optimizations on smart power flows of vehicle-to-grid interaction and electrolyzer are conducted for further seasonal grid stability and annual cost saving. The obtained results indicate that, the green renewable-to-hydrogen can effectively reduce reliance on pipelines delivered hydrogen, and the hydrogen station is effective to address security concerns of high-pressure hydrogen and improve participators’ acceptance. Microgrid peer-to-peer sharing can improve hydrogen system efficiency under idling modes. Furthermore, the integrated system can reduce the annual net hydrogen consumption in transportation from 127.0 to 1.2 kg/vehicle. The smart operation (minimum input power of electrolyzer and fuel cell at 65 and 80 kW) can reduce the maximum mean hourly grid power to 78.2 kW by 24.2% and the annual energy cost to 1228.5 $/household by 38.9%. The proposed district hydrogen-based community framework can provide cutting-edge techno-economic guidelines for carbon-neutral transition with district peer-to-peer energy sharing, zero-energy buildings, hydrogen-based transportations together with smart strategies for high energy flexibility.","Distributed hydrogen infrastructure; Distributed renewable energy sharing; Flexible energy management strategy; Hydrogen energy storage and economy; Solar energy","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-04-09","","","Housing Quality and Process Innovation","","",""
"uuid:55734d44-fc9f-4e7c-8e26-ebae8b4d3fcd","http://resolver.tudelft.nl/uuid:55734d44-fc9f-4e7c-8e26-ebae8b4d3fcd","Intuitionistic Fuzzy Laplacian Twin Support Vector Machine for Semi-supervised Classification","Zhou, Jia Bin (Shanghai University); Bai, Yan Qin (Shanghai University); Guo, Y. (Shanghai University); Lin, H.X. (TU Delft Mathematical Physics; TU Delft Delft Institute of Applied Mathematics)","","2021","In general, data contain noises which come from faulty instruments, flawed measurements or faulty communication. Learning with data in the context of classification or regression is inevitably affected by noises in the data. In order to remove or greatly reduce the impact of noises, we introduce the ideas of fuzzy membership functions and the Laplacian twin support vector machine (Lap-TSVM). A formulation of the linear intuitionistic fuzzy Laplacian twin support vector machine (IFLap-TSVM) is presented. Moreover, we extend the linear IFLap-TSVM to the nonlinear case by kernel function. The proposed IFLap-TSVM resolves the negative impact of noises and outliers by using fuzzy membership functions and is a more accurate reasonable classifier by using the geometric distribution information of labeled data and unlabeled data based on manifold regularization. Experiments with constructed artificial datasets, several UCI benchmark datasets and MNIST dataset show that the IFLap-TSVM has better classification accuracy than other state-of-the-art twin support vector machine (TSVM), intuitionistic fuzzy twin support vector machine (IFTSVM) and Lap-TSVM.","Intuitionistic fuzzy; Manifold regularization; Noisy data; Semi-supervised classification; Twin support vector machine","en","journal article","","","","","","","","","","","Mathematical Physics","","",""
"uuid:88ef1429-ddc4-437e-a3ae-dc9de0e2a7c2","http://resolver.tudelft.nl/uuid:88ef1429-ddc4-437e-a3ae-dc9de0e2a7c2","Deep learning–based nondestructive evaluation of reinforcement bars using ground-penetrating radar and electromagnetic induction data","Li, Xiaofeng (China University of Geosciences, Wuhan); Liu, Hai (Guangzhou University); Zhou, Feng (China University of Geosciences, Wuhan); Chen, Zhongchang (China University of Geosciences, Wuhan); Giannakis, Iraklis (University of Aberdeen); Slob, E.C. (TU Delft Applied Geophysics and Petrophysics)","","2021","This paper proposes a nondestructive evaluation method based on deep learning using combined ground-penetrating radar (GPR) and electromagnetic induction (EMI) data for autonomic and accurate estimation of the cover thickness and diameter of reinforcement bars. A real-time object detection algorithm—You Only Look Once–version 3 (YOLO v3)—is adopted to automatically identify the reinforcement bar reflected signals from radargrams, with which the range of the cover thickness is roughly predicted. Subsequently, EMI data, accompanied with the cover thickness range, are imported to a one-dimensional convolutional neural network (1D CNN), pretrained by calibrated EMI and GPR data, to simultaneously estimate the cover thickness and reinforcement bar diameter. Testing with the on-site GPR data shows that YOLO v3 is superior to Single Shot Multibox Detector method in GPR hyperbolic signal identification. Testing of 1D CNN with the EMI and GPR data collected in an in-house sand pit experiment shows that the estimation accuracy of the cover thickness and reinforcement bar diameter is, respectively, 96.8% and 90.3% with a permissible error of 1 mm. Further, an experiment with concrete specimens demonstrates that among the 22 estimated values (including the reinforcement bar diameter and cover thickness), there are 17 values accurately estimated, while the inaccurately estimated values have an error up to 2 mm. The experimental results show that the proposed method can autonomically evaluate the reinforcement bar diameter and cover thickness with a high accuracy.","","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2022-05-26","","","Applied Geophysics and Petrophysics","","",""
"uuid:4f613daf-78b2-495e-967e-e1d37dca348e","http://resolver.tudelft.nl/uuid:4f613daf-78b2-495e-967e-e1d37dca348e","Compact energy–time entanglement source using cascaded nonlinear interactions","Lefebvre, P. (University of Calgary); Valivarthi, R. (University of Calgary; California Institute of Technology); Zhou, Q. (University of Calgary; University of Electronic Science and Technology of China); Oesterling, L. (Battelle Memorial Institute); Oblak, D. (University of Calgary); Tittel, W. (TU Delft QID/Tittel Lab; TU Delft Quantum Communications Lab; University of Calgary; Kavli institute of nanoscience Delft)","","2021","Entangled photon pair sources are essential for applications such as quantum communication and metrology. Here we present a compact energy–time entangled photon pair source at telecom wavelengths realized through cascaded second harmonic generation and spontaneous parametric down conversion in a single periodically poled lithium niobate waveguide. We introduce and characterize methods to diminish the effects of Raman scattering, the principal being quasi-CW pumping. The quality of energy–time entanglement produced by the compact source is analyzed using two-photon interference and Franson interference, and visibilities as high as 93.9% ± 0.4% and 90.5% ± 0.6% are achieved, respectively.","","en","journal article","","","","","","Accepted Author Manuscript","","2022-03-31","","","QID/Tittel Lab","","",""
"uuid:92cb348f-a749-45b5-b55d-d4005d4673a7","http://resolver.tudelft.nl/uuid:92cb348f-a749-45b5-b55d-d4005d4673a7","Experimental study on evacuation behaviour of passengers in a high-deck coach: A Chinese case study","Huang, Rong (Chang'an University); Zhao, Xuan (Chang'an University); Yuan, Y. (TU Delft Transport and Planning); Yu, Qiang (Chang'an University); Zhou, Chenyu (Chang'an University); Daamen, W. (TU Delft Transport and Planning)","","2021","High-deck coaches form an essential component of mass transportation systems in China. Safe evacuation from high-deck coaches is facing dire challenges. However, evacuation behaviour from high-deck coaches has not been deeply understood yet. In this study, a novel conceptual framework is firstly proposed to capture the evacuation behaviour of coach passengers, and next based on which 22 full-scale experiments have been conducted to examine the effect of three selected factors: available exits, lighting conditions and age groups on the evacuation behaviour of Chinese passengers in a high-deck coach, in a systematic and quantitative way. Four performance indicators of evacuation behaviour, i.e., evacuation time, pre-evacuation time, flow rate and crowdedness, were collected and analysed. The results indicate that limited available exits and the dim lighting condition (less than 1 lux) significantly reduce the evacuation efficiency and increase the crowdedness within the aisle area regardless of the age groups. Compared to young students, the evacuation of middle-aged people is observed to have a significantly longer pre-evacuation time, lower evacuation efficiency, and higher level of crowdedness. In addition, young students’ pre-evacuation times are found to conform to the Weibull distribution, whereas middle-aged people’ pre-evacuation times could be modelled with the Loglogistic distribution. Empirical results of this study could be helpful for the improvement of the safety design of high-deck coaches, and provide valuable benchmarks for the development of coach evacuation behaviour and simulation models.","Chinese passengers; Evacuation behaviour; Evacuation experiment; High-deck coaches; Pre-evacuation","en","journal article","","","","","","","","","","","Transport and Planning","","",""
"uuid:867583c1-7189-4240-89b3-19ee021ccac0","http://resolver.tudelft.nl/uuid:867583c1-7189-4240-89b3-19ee021ccac0","New innovations in pavement materials and engineering: A review on pavement engineering research 2021","Chen, Jiaqi (Central South University China); Dan, Hancheng (Central South University China); Ding, Yongjie (Chongqing Jiaotong University); Gao, Y. (TU Delft Pavement Engineering); Guo, Meng (Beijing University of Technology); Guo, Shuaicheng (Hunan University); Han, Bingye (Beijing University of Civil Engineering & Architecture); Hong, Bin (Harbin Institute of Technology); Hou, Yue (Beijing University of Technology); Hu, Chichun (South China University of Technology); Hu, Jing (Southeast University); Huyan, Ju (Southeast University; University of Waterloo); Jiang, Jiwang (The Hong Kong Polytechnic University); Jiang, Wei (Chang'an University); Li, Cheng (Chang'an University); Liu, Pengfei (Rheinisch-Westfälische Technische Hochschule); Liu, Yu (Chang'an University); Liu, Zhuangzhuang (Chang'an University); Lu, Guoyang (The Hong Kong Polytechnic University); Ouyang, Jian (Dalian University of Technology); Qu, Xin (Chang'an University); Ren, Dongya (Southwest Jiaotong University); Wang, Chao (Beijing University of Technology); Wang, Chaohui (Chang'an University); Wang, Dawei (Harbin Institute of Technology); Wang, Di (Aalto University); Wang, Hainian (Chang'an University); Wang, Haopeng (University of Nottingham); Xiao, Yue (Wuhan University; Wuhan University of Technology); Xing, Chao (Harbin Institute of Technology); Xu, Huining (Harbin Institute of Technology); Yan, Yu (Tongji University); Yang, Xu (Chang'an University); You, Lingyun (Huazhong University of Science and Technology); You, Zhanping (Michigan Technological University); Yu, Bin (Southeast University); Yu, Huayang (South China University of Technology); Yu, Huanan (Changsha University of Science and Technology); Zhang, Henglong (Hunan University); Zhang, Jizhe (Shandong University); Zhou, Changhong (Guilin University of Electronic Technology); Zhou, Changjun (Dalian University of Technology); Zhu, Xingyi (Tongji University)","","2021","Sustainable and resilient pavement infrastructure is critical for current economic and environmental challenges. In the past 10 years, the pavement infrastructure strongly supports the rapid development of the global social economy. New theories, new methods, new technologies and new materials related to pavement engineering are emerging. Deterioration of pavement infrastructure is a typical multi-physics problem. Because of actual coupled behaviors of traffic and environmental conditions, predictions of pavement service life become more and more complicated and require a deep knowledge of pavement material analysis. In order to summarize the current and determine the future research of pavement engineering, Journal of Traffic and Transportation Engineering (English Edition) has launched a review paper on the topic of “New innovations in pavement materials and engineering: A review on pavement engineering research 2021”. Based on the joint-effort of 43 scholars from 24 well-known universities in highway engineering, this review paper systematically analyzes the research status and future development direction of 5 major fields of pavement engineering in the world. The content includes asphalt binder performance and modeling, mixture performance and modeling of pavement materials, multi-scale mechanics, green and sustainable pavement, and intelligent pavement. Overall, this review paper is able to provide references and insights for researchers and engineers in the field of pavement engineering.","Asphalt binder; Asphalt mixture; Green and sustainable pavement; Intelligent pavement; Modeling of pavement materials; Multi-scale mechanics","en","review","","","","","","","","","","","Pavement Engineering","","",""
"uuid:4fe313d7-af50-4adb-afb6-917df38308d7","http://resolver.tudelft.nl/uuid:4fe313d7-af50-4adb-afb6-917df38308d7","The aging effect in evolving scientific citation networks","Hu, Feng (Qinghai Normal University; Ministry of Education Hangzhou; Tibetan Information Processing and Machine Translation Key Laboratory of Qinghai Province); Ma, Lin (Hangzhou Normal University); Zhan, X. (TU Delft Multimedia Computing; Hangzhou Normal University); Zhou, Yinzuo (Hangzhou Normal University); Liu, Chuang (Hangzhou Normal University); Zhao, Haixing (Qinghai Normal University; Ministry of Education Hangzhou; Tibetan Information Processing and Machine Translation Key Laboratory of Qinghai Province); Zhang, Zi Ke (Hangzhou Normal University; College of Media and International Culture)","","2021","The study of citation networks is of interest to the scientific community. However, the underlying mechanism driving individual citation behavior remains imperfectly understood, despite the recent proliferation of quantitative research methods. Traditional network models normally use graph theory to consider articles as nodes and citations as pairwise relationships between them. In this paper, we propose an alternative evolutionary model based on hypergraph theory in which one hyperedge can have an arbitrary number of nodes, combined with an aging effect to reflect the temporal dynamics of scientific citation behavior. Both theoretical approximate solution and simulation analysis of the model are developed and validated using two benchmark datasets from different disciplines, i.e. publications of the American Physical Society (APS) and the Digital Bibliography & Library Project (DBLP). Further analysis indicates that the attraction of early publications will decay exponentially. Moreover, the experimental results show that the aging effect indeed has a significant influence on the description of collective citation patterns. Shedding light on the complex dynamics driving these mechanisms facilitates the understanding of the laws governing scientific evolution and the quantitative evaluation of scientific outputs.","Aging effect; Evolution; Hypergraph theory; Scientific citation network","en","journal article","","","","","","","","","","","Multimedia Computing","","",""
"uuid:ce32dca4-4301-4804-ba57-2acd93aafbc7","http://resolver.tudelft.nl/uuid:ce32dca4-4301-4804-ba57-2acd93aafbc7","Velocity and turbulence affected by various vegetations in open channel","Sun, Zhilin (Zhejiang University); Meng, Xin (Zhejiang University); Zhou, Y. (TU Delft Applied Mechanics)","","2021","Water energy is a conventional source of source that is widely available in nature. It can be easily converted into high quality secondary energy-electric energy through hydroelectric power stations. Hydropower is not only a widely used conventional energy source, but also a renewable energy source. Moreover, hydroelectric power has no pollution to the environment. Therefore, water energy is an inexhaustible and high-quality energy source among many energy sources in the world. However, vegetation can change flow structure and turbulence characteristics, impacting the use of water energy. In previous researches, few studies have focused on the comparison of velocity and turbulence influenced by various vegetations. Therefore, laboratory experiments were carried out to investigate hydrodynamics affected by submerged rigid vegetation (reed and wooden stick) and merged flexible vegetation (grass and chlorella) under different conditions. The time-averaged velocity distributions of planted floodplain are not logarithmic. Instead, reed and wooden stick followed an ""S-shape""profile, but for grass and chlorella, they presented reverse S-shape profile. For all cases, turbulence is not isotropic and the change law of turbulence intensity is different in different sections.","","en","journal article","","","","","","","","","","","Applied Mechanics","","",""
"uuid:7852e5cd-7f25-42e6-96e5-856baa2b63df","http://resolver.tudelft.nl/uuid:7852e5cd-7f25-42e6-96e5-856baa2b63df","Investigation on rail corrugation grinding criterion based on coupled vehicle–track dynamics and rolling contact fatigue model","Liang, Hongqin (Southwest Jiaotong University); Li, Wei (Southwest Jiaotong University); Zhou, Zhijun (Southwest Jiaotong University); Wen, Zefeng (Southwest Jiaotong University); Li, S. (TU Delft Railway Engineering); An, Dong (Southwest Jiaotong University)","","2021","Based on the measured spectra of rail roughness and track structures longitudinal roughness, the rail grinding limit is studied with the help of an established coupled dynamic metro vehicle–track model and a rolling contact fatigue model. The results indicate that metro rail grinding control should be regulated according to corrugation wavelength range and operating speed. Based on the rolling contact fatigue model, longer wavelength of rail corrugation has less influence on the wheel rolling contact fatigue. For the metro lines with a maximum operating speed of 80 km/h, the average levels of rail corrugation in the wavelength ranges of 30–65 mm, 65–125 mm, and 125–250 mm should be less than 5.4, 24.8, and 33.8 dB re 1 μm, respectively; for the ones with the operating speed of 80–120 km/h, the corresponding average corrugation levels in the three wavelength ranges should be less than 4.4, 9.8, and 29.8 dB re 1 μm, respectively.","corrugation limit; grinding; Metro rail corrugation; rolling contact fatigue; vehicle–track model","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2021-07-31","","","Railway Engineering","","",""
"uuid:d763c918-6e96-403b-810d-7085fb83ceb0","http://resolver.tudelft.nl/uuid:d763c918-6e96-403b-810d-7085fb83ceb0","Extrusion-based 3D printed magnesium scaffolds with multifunctional MgF2and MgF2-CaP coatings","Dong, J. (TU Delft Biomaterials & Tissue Biomechanics); Tümer, N. (TU Delft Biomaterials & Tissue Biomechanics); Putra, N.E. (TU Delft Biomaterials & Tissue Biomechanics); Zhu, Jia-Ning (TU Delft Team Vera Popovich); Li, Y. (University of Science and Technology Beijing); Leeflang, M.A. (TU Delft Biomaterials & Tissue Biomechanics); Taheri, P. (TU Delft Team Peyman Taheri); Fratila-Apachitei, E.L. (TU Delft Biomaterials & Tissue Biomechanics); Mol, J.M.C. (TU Delft Team Arjan Mol); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2021","Additively manufactured (AM) biodegradable magnesium (Mg) scaffolds with precisely controlled and fully interconnected porous structures offer unprecedented potential as temporary bone substitutes and for bone regeneration in critical-sized bone defects. However, current attempts to apply AM techniques, mainly powder bed fusion AM, for the preparation of Mg scaffolds, have encountered some crucial difficulties related to safety in AM operations and severe oxidation during AM processes. To avoid these difficulties, extrusion-based 3D printing has been recently developed to prepare porous Mg scaffolds with highly interconnected structures. However, limited bioactivity and a too high rate of biodegradation remain the major challenges that need to be addressed. Here, we present a new generation of extrusion-based 3D printed porous Mg scaffolds that are coated with MgF2 and MgF2-CaP to improve their corrosion resistance and biocompatibility, thereby bringing the AM scaffolds closer to meeting the clinical requirements for bone substitutes. The mechanical properties, in vitro biodegradation behavior, electrochemical response, and biocompatibility of the 3D printed Mg scaffolds with a macroporosity of 55% and a strut density of 92% were evaluated. Furthermore, comparisons were made between the bare scaffolds and the scaffolds with coatings. The coating not only covered the struts but also infiltrated the struts through micropores, resulting in decreases in both macro- and micro-porosity. The bare Mg scaffolds exhibited poor corrosion resistance due to the highly interconnected porous structure, while the MgF2-CaP coatings remarkably improved the corrosion resistance, lowering the biodegradation rate of the scaffolds down to 0.2 mm y-1. The compressive mechanical properties of the bare and coated Mg scaffolds before and during in vitro immersion tests for up to 7 days were both in the range of the values reported for the trabecular bone. Moreover, direct culture of MC3T3-E1 preosteoblasts on the coated Mg scaffolds confirmed their good biocompatibility. Overall, this study clearly demonstrated the great potential of MgF2-CaP coated porous Mg prepared by extrusion-based 3D printing for further development as a bone substitute. This journal is","","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:07bd1f96-4d83-4d5b-b289-ee72f72eea3f","http://resolver.tudelft.nl/uuid:07bd1f96-4d83-4d5b-b289-ee72f72eea3f","Modeling the underlying drivers of natural vegetation occurrence in west africa with binary logistic regression method","Barnieh, Beatrice Asenso (Chinese Academy of Sciences; University of Chinese Academy of Sciences); Jia, Li (Chinese Academy of Sciences); Menenti, M. (TU Delft Optical and Laser Remote Sensing; Chinese Academy of Sciences); Jiang, Min (Chinese Academy of Sciences); Zhou, Jie (Central China Normal University); Zeng, Yelong (Chinese Academy of Sciences; University of Chinese Academy of Sciences); Bennour, Ali (Chinese Academy of Sciences; University of Chinese Academy of Sciences)","","2021","The occurrence of natural vegetation at a given time is determined by interplay of multiple drivers. The effects of several drivers, e.g., geomorphology, topography, climate variability, accessibility, demographic indicators, and changes in human activities on the occurrence of natural vegetation in the severe drought periods and, prior to the year 2000, have been analyzed in West Africa. A binary logistic regression (BLR) model was developed to better understand whether the variability in these drivers over the past years was statistically significant in explaining the occurrence of natural vegetation in the year 2000. Our results showed that multiple drivers explained the occurrence of natural vegetation in West Africa at p < 0.05. The dominant drivers, however, were site-specific. Overall, human influence indicators were the dominant drivers in explaining the occurrence of natural vegetation in the selected hotspots. Human appropriation of net primary productivity (HANPP), which is an indicator of human socio-economic activities, explained the decreased likelihood of natural vegetation occurrence at all the study sites. However, the impacts of the remaining significant drivers on natural vegetation were either positive (increased the probability of occurrence) or negative (decreased the probability of occurrence), depending on the unique environmental and socio-economic conditions of the areas under consideration. The study highlights the significant role human activities play in altering the normal functioning of the ecosystem by means of a statistical model. The research contributes to a better understanding of the relationships and the interactions between multiple drivers and the response of natural vegetation in West Africa. The results are likely to be useful for planning climate change adaptation and sustainable development programs in West Africa.","Binary logistic regression; Climate; Human activities; Natural vegetation; Underlying drivers; West Africa","en","journal article","","","","","","","","","","","Optical and Laser Remote Sensing","","",""
"uuid:5a772bd5-bedb-4081-a68a-fc7f61b7c849","http://resolver.tudelft.nl/uuid:5a772bd5-bedb-4081-a68a-fc7f61b7c849","Degradation behaviors and in-vivo biocompatibility of a rare earth- and aluminum-free magnesium-based stent","Bian, Dong (Guangdong Academy of Medical Sciences); Zhou, Xiaochen (Peking University); Liu, Jianing (Peking University); Li, Wenting (Peking University); Shen, Danni (Peking University); Zheng, Yufeng (Peking University; Guangdong Academy of Medical Sciences); Gu, Wenda (Guangdong Academy of Medical Sciences); Jiang, Jingjun (Peking University People’s Hospital); Li, Mei (Guangdong Academy of Medical Sciences); Chu, Xiao (Guangdong Academy of Medical Sciences); Ma, Limin (Guangdong Academy of Medical Sciences); Wang, Xiaolan (Guangdong Academy of Medical Sciences); Zhang, Yu (Guangdong Academy of Medical Sciences); Leeflang, M.A. (TU Delft Biomaterials & Tissue Biomechanics); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2021","Biodegradable stents can provide scaffolding and anti-restenosis benefits in the short term and then gradually disappear over time to free the vessel, among which the Mg-based biodegradable metal stents have been prosperously developed. In the present study, a Mg-8.5Li (wt.%) alloy (RE- and Al-free) with high ductility (> 40%) was processed into mini-tubes, and further fabricated into finished stent through laser cutting and electropolishing. In-vitro degradation test was performed to evaluate the durability of this stent before and after balloon dilation. The influence of plastic deformation and residual stress (derived from the dilation process) on the degradation was checked with the assistance of finite element analysis. In addition, in-vivo degradation behaviors and biocompatibility of the stent were evaluated by performing implantation in iliac artery of minipigs. The balloon dilation process did not lead to deteriorated degradation, and this stent exhibited a decent degradation rate (0.15 mm/y) in vitro, but divergent result (> 0.6 mm/y) was found in vivo. The stent was almost completely degraded in 3 months, revealing an insufficient scaffolding time. Meanwhile, it did not induce possible thrombus, and it was tolerable by surrounding tissues in pigs. Besides, endothelial coverage in 1 month was achieved even under the severe degradation condition. In the end, the feasibility of this stent for treatment of benign vascular stenosis was generally discussed, and perspectives on future improvement of Mg-Li-based stents were proposed.","Biocompatibility; Biodegradable stent; Degradation behavior; Iliac artery; Mg-Li alloy","en","journal article","","","","","","Accepted Author Manuscript","","2023-03-20","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:ef52ab26-2cfb-4299-a86a-e79f90a5bad2","http://resolver.tudelft.nl/uuid:ef52ab26-2cfb-4299-a86a-e79f90a5bad2","Shear-slip behaviour of prefabricated composite shear stud connectors in composite bridges","Gao, Yanmei (Chongqing Jiaotong University); Li, Chengjun (Sichuan Vocational and Technical College of Communications); Wang, Xuefei (Chongqing Jiaotong University); Zhou, Zhixiang (Shenzhen University); Fan, Liang (Chongqing Jiaotong University); Heng, J. (TU Delft Steel & Composite Structures; Shenzhen University)","","2021","This paper has investigated the shear-slip behaviour of an innovative prefabricated composite shear stud (PCSS) connector and its application in the prefabricated steel–concrete composite bridges. A series of push-out tests are carried out on a total of 12 specimens, including 6 PCSS specimens and 6 conventional shear stud (CSS) specimens. Further comparison has been carried out between the test result and the data available from the literature. Based on the test, a high-resolution finite element (FE) analysis has been performed to reveal the load transfer mechanism of the PCSS connector at the component-level. After that, an advanced FE model has been established and validated by a full-scale test of the prefabricated composite bridge using the PCSS. With the FE model, the load-slip behaviour and slip distribution are investigated in details. The result highlights the enhanced shear capacity and ductility of the PCSS specimens compared with the CSS specimens, as well as the feasibility of PCSS connectors in composite bridges. Meanwhile, it is further revealed by the detailed investigation that the enhancement could be attributed to the lateral constraint on the concrete by the vertical steel plate in the PCSS. Besides, it is also found that the load-slip behaviour of composite bridges using the PCSS is influenced by the cracking at the seam between deck blocks. Consequently, abrupt changes can be found in the load-slip curve once the cracking occurs, which differs from the traditional composite bridges.","High-resolution finite element analysis; Load-transfer mechanism; Prefabricated composite shear studs connector; Prefabricated steel–concrete composite bridge; Push-out test; Shear-slip behaviour","en","journal article","","","","","","Accepted Author Manuscript","","2023-05-04","","","Steel & Composite Structures","","",""
"uuid:2b68249b-ea1d-44c7-8d74-a98bc1b80a78","http://resolver.tudelft.nl/uuid:2b68249b-ea1d-44c7-8d74-a98bc1b80a78","Identify dominant dimensions of 3D hand shapes using statistical shape model and deep neural network","Yang, Y. (TU Delft Mechatronic Design; Shanghai University); Zhou, H. (TU Delft Robot Dynamics); Song, Y. (TU Delft Mechatronic Design); Vink, P. (TU Delft Materials and Manufacturing)","","2021","Hand anthropometry is one of the fundamentals of ergonomic research and product design. Many studies have been conducted to analyze the hand dimensions among different populations, however, the definitions and the numbers of those dimensions were usually selected based on the experience of the researchers and the available equipment. Few studies explored the importance of each hand dimension regarding the 3D shape of the hand. In this paper, we aim to identify the dominant dimensions that influence the hand shape variability while considering the stability of the measurements in practice. A novel four-step research method was proposed where in the first step, based on literature study, we defined 58 landmarks and 53 dimensions for the exploration. In the second step, 80,000 virtual hand models, each had the associated 53 dimensions, were augmented by changing the weights of Principle Components (PCs) of a statistical shape model (SSM). Deep neural networks (DNNs) were used to establish the inverse relationships from the dimensions to the weight of each PC of the hand SSM. Using the structured sparsity learning method, we identified 21 dominant dimensions that represent 90% of the variance of the hand shape. In the third step, two different manual measuring methods were used to evaluate the stability of the measurements in practice. Finally, we selected 16 dominant dimensions with lower measurement variance by synthesizing the findings in Step 2 and 3. It was concluded that the recognized 21 dominant dimensions can be treated as the reference dimensions for anthropometric study and using the selected 16 dominant dimensions with lower measurement variance, ergonomists are able to generate a 3D hand model based on simple measurement tools with an accuracy of 5.9 mm. Though the accuracy is limited, the efforts are minimum, and the results can be used as an indicator in the early stage of research/design.","Dominant hand dimensions; Measurement stability; Structured sparsity learning","en","journal article","","","","","","","","","","","Mechatronic Design","","",""
"uuid:4122ce24-5973-4afc-a084-1520dc8c5738","http://resolver.tudelft.nl/uuid:4122ce24-5973-4afc-a084-1520dc8c5738","Development of a nature-based Geo-engineering solution to reduce soil permeability in-situ","Zhou, Jianchao (TU Delft Geo-engineering)","Heimovaara, T.J. (promotor); Jansen, B. (copromotor); Delft University of Technology (degree granting institution)","2020","Stability of dikes is a national security issue for densely populated low-lying countries situated in delta areas, like the Netherlands. One of the dominant dike failuremechanisms in the Netherlands is piping, where high seepage flow rates transport sand particles and subsequently form a ’pipe’ under a dike structure. As such, one manner to reinforce dike lies in the modification of the seepage flow field. Though many of conventional approaches have demonstrated varied degree of success in creating flow barrier, which is a subsurface structure that can alter the seepage flow field, they are commonly costly in terms of energy and labour. Facing the ever-growing awareness of climate change as well as the large economic scale of the dike stability issue in the Netherlands, the development of alternative techniques is thus desired. The focus of this research project is to develop a cost-effective, robust and environmentally compatible technology for insitu permeability reduction of sub-surface systems. We took inspiration from nature, where a natural soil stratification process (namely Podzolization) shows the viability of organo-metallic complexes precipitation in reducing soil permeability in-situ. The aim of the research presented in this thesis is to quantitatively study the feasibility of using Podzolization-derived approaches to install flow barrier in dikes. Chapter 2 of this thesis presents two approaches for applying organo-metallic complexes to reduce soil permeability in-situ, which are derived from the detailed analysis of Podzolization and the flocculation process between metal salt with organic matter. The first approach bases on the in-situ mixing and reaction between two components (i.e., aluminium (Al) and organic matter (OM) solutions), while the second approach makes use of the direct injection of Al-OM flocs. To understand the feasibility of using these approaches to install flow barrier on site, a 3D process-oriented model was developed. An important aspect of this model development is to incorporate engineering conditions on site into the simulation of processes. A series of scenario analyses were therefore performed with the model in order to facilitate the design and evaluation of the full-scale experiments where the two delivery approaches were applied to install a flow barrier in two dikes.","building with nature; in-situ permeability reduction; metal-organic matter complexation; flow barrier; reactive transport modelling; metal-organicmatter flocs","en","doctoral thesis","","978-94-6366-288-8","","","","","","","","","Geo-engineering","","",""
"uuid:89466e36-b579-4943-b3da-b251dd52209f","http://resolver.tudelft.nl/uuid:89466e36-b579-4943-b3da-b251dd52209f","Combining LiDAR and Photogrammetry to Generate Up-to-date 3D City Models","Zhou, K. (TU Delft Mathematical Geodesy and Positioning)","Hanssen, R.F. (promotor); Lindenbergh, R.C. (promotor); Delft University of Technology (degree granting institution)","2020","3D city models are increasingly used to maintain and improve urban infrastructure. Keeping 3D city models accurate and up-to-date is essential for municipalities to make decisions in a time of strongly increasing urbanization. 3D information provided by airborne laser scanning (ALS) is widely used for generating 3D city models. However, ALS data is sparse and irregularly spaced, and not frequently acquired due to its high costs. Airborne camera imagery (ACIM) is an alternative to extract denser but less accurate 3D information. Given these limitations in acquisition frequency and quality, using either ALS or ACIM to generate up-to-date large-scale 3D city models is sub-optimal. Therefore, we combine the complementary characteristics of both data sources to achieve two objectives: (i) 3D change detection and updating of buildings in ALS data using ACIM data, and (ii) improving the planimetric accuracy of building extraction from ALS data using ACIM data. ALS data is integrated with a single image or a single stereo pair for the first objective, and with multiple stereo pairs for the second objective. Our methods are validated over three areas: Vaihingen, Germany, and Amersfoort and Assen, the Netherlands. Shadow in a single image is indicative for a 3D object and is represented in the image by RGB color values. However, these color values are not unique, as they depend on the local conditions, such as material and environment. We propose a supervised machine learning approach, random forest, to effectively characterize the color properties. To generate training samples, accelerated ray tracing is used to efficiently reconstruct shadow locations in the image using 3D ALS data. Using shadow alone is not sufficient to detect accurate building changes, as shadows only partially represent 3D information. 3D information can be extracted from corresponding pixels in a stereo pair, but this information is not accurate in shadow and low texture areas. To address this, we propose LEAD-Matching (LiDAR-guided edge-aware dense matching). It starts from using accurate plane information extracted from ALS data to densify sparse ALS points. Three candidate heights are then obtained for each densified point to guide the dense matching in these problematic areas. Subsequently, detailed building information in the stereo pair is integrated to choose the final optimal height. If the optimal height obtained by LEAD-Matching points to corresponding pixels of different color, a likely building change is found. Test results on the Amersfoort and Assen data show a successful verification of unchanged buildings while changes are detected starting from 2 × 2 × 2 m 3 , as conventionally required for large-scale 3D mapping, with an F1 score of 0.8 and 0.9 respectively. To achieve the second objective, we extend LEAD-Matching to multiple stereo pairs, to improve the planimetric accuracy of building extraction in ALS data. E-LEAD-Matching integrates building boundaries of high planimetric accuracy from multiple stereo pairs to the ALS data. Using multiple stereo pairs, occlusions in single stereo pairs are compensated, while the accuracy of building boundaries is improved. Compared to using ALS alone, the planimetric accuracy of extracted buildings improves from 0.40 m to 0.22 m in Vaihingen, and from 0.48 m to 0.21 m in Amersfoort. This improved planimetric accuracy actually meets conventional requirements of large-scale mapping. Our methods enable us to integrate the beneficial aspects from ALS and ACIM to generate accurate and up-to-date large-scale 3D city models. We anticipate that our research will save both money and time in generating future up-to-date large-scale 3D city models.","Airborne laser scanning; Airborne images; 3D city model; Change detection; Dense matching; Supervised learning; Multi-view Photogrammetry; LIDAR; Photogrammetry; building model; large scale mapping","en","doctoral thesis","","978-94-6366-278-9","","","","","","","","","Mathematical Geodesy and Positioning","","",""
"uuid:38075b4f-aeed-4e73-95cf-463a977dcb61","http://resolver.tudelft.nl/uuid:38075b4f-aeed-4e73-95cf-463a977dcb61","Additively manufactured biodegradable porous metals","Li, Y. (TU Delft Biomaterials & Tissue Biomechanics); Jahr, H. (Medizinische Fakultat und Universitats Klinikum Aachen; Maastricht UMC); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2020","Partially due to the unavailability of ideal bone substitutes, the treatment of large bony defects remains one of the most important challenges of orthopedic surgery. Additively manufactured (AM) biodegradable porous metals that have emerged since 2018 provide unprecedented opportunities for fulfilling the requirements of an ideal bone implant. First, the multi-scale geometry of these implants can be customized to mimic the human bone in terms of both micro-architecture and mechanical properties. Second, a porous structure with interconnected pores possesses a large surface area, which is favorable for the adhesion and proliferation of cells and, thus, bony ingrowth. Finally, the freeform geometrical design of such biomaterials could be exploited to adjust their biodegradation behavior so as to maintain the structural integrity of the implant during the healing process while ensuring that the implant disappears afterwards, paving the way for full bone regeneration. While the AM biodegradable porous metals that have been studied so far have shown many unique properties as compared to their solid counterparts, the unprecedented degree of flexibility in their geometrical design has not yet been fully exploited to optimize their properties and performance. In order to develop the ideal bone implants, it is important to take advantage of the full potential of AM biodegradable porous metals through detailed and systematic study on their biodegradation behavior, mechanical properties, biocompatibility, and bone regeneration performance. This review paper presents the state of the art in AM biodegradable porous metals and is focused on the effects of material type, processing, geometrical design, and post-AM treatments on the mechanical properties, biodegradation behavior, in vitro biocompatibility, and in vivo bone regeneration performance of AM porous Mg, Fe, and Zn as well as their alloys. We also identify a number of knowledge gaps and the challenges encountered in adopting AM biodegradable porous metals for orthopedic applications and suggest some promising areas for future research.","Additive manufacturing; Biocompatibility; Biodegradation; Mechanical property; Metal; Scaffold","en","review","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:e40fb8de-6f99-4802-b5b5-5990c61d08a2","http://resolver.tudelft.nl/uuid:e40fb8de-6f99-4802-b5b5-5990c61d08a2","Open for business: The impact of creative team environment and innovative behaviour in technology-based start-ups","Zhou, Zhao (Shanghai University of Finance and Economics); Verburg, R.M. (TU Delft Economics of Technology and Innovation)","","2020","Rather than the view of the entrepreneur as a ‘lone ranger’, recent work has focused on the importance of teams in bringing a start-up to growth and success. Here, we aim to bridge the gap between the individual characteristics of entrepreneurs and the characteristics of their teams by examining openness of founders in relation to creative team environment (CTE), innovative work behaviour (IWB) and performance. On the basis of upper echelon theory and integrating other complementary theories such as the attention-based view, we develop a theoretical framework and test this using a survey of 322 high-tech entrepreneurs. Our findings suggest a mediating role of CTE and IWB in the relation between openness of entrepreneurs and performance. The implications of the results for managerial practices and future research directions are discussed.","creative team environment; entrepreneurship; innovative work behaviour; openness to experience; technology-based start-ups","en","journal article","","","","","","","","","","","Economics of Technology and Innovation","","",""
"uuid:8c545e9e-9c22-4b9b-a329-dc9288d8a86a","http://resolver.tudelft.nl/uuid:8c545e9e-9c22-4b9b-a329-dc9288d8a86a","Multi-material additive manufacturing technologies for Ti-, Mg-, and Fe-based biomaterials for bone substitution","Putra, N.E. (TU Delft Biomaterials & Tissue Biomechanics); Mirzaali, Mohammad J. (TU Delft Biomaterials & Tissue Biomechanics); Apachitei, I. (TU Delft Biomaterials & Tissue Biomechanics); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2020","The growing interest in multi-functional metallic biomaterials for bone substitutes challenges the current additive manufacturing (AM, =3D printing) technologies. It is foreseeable that advances in multi-material AM for metallic biomaterials will not only allow for complex geometrical designs, but also improve their multi-functionalities by tuning the types or compositions of the underlying base materials, thereby presenting unprecedented opportunities for advanced orthopedic treatments. AM technologies are yet to be extensively explored for the fabrication of multi-functional metallic biomaterials, especially for bone substitutes. The aim of this review is to present the viable options of the state-of-the-art multi-material AM for Ti-, Mg-, and Fe-based biomaterials to be used as bone substitutes. The review starts with a brief review of bone tissue engineering, the design requirements, and fabrication technologies for metallic biomaterials to highlight the advantages of using AM over conventional fabrication methods. Five AM technologies suitable for metal 3D printing are compared against the requirements for multi-material AM. Of these AM technologies, extrusion-based multi-material AM is shown to have the greatest potential to meet the requirements for the fabrication of multi-functional metallic biomaterials. Finally, recent progress in the fabrication of Ti-, Mg-, and Fe-based biomaterials including the utilization of multi-material AM technologies is reviewed so as to identify the knowledge gaps and propose the directions of further research for the development of multi-material AM technologies that are applicable for the fabrication of multi-functional metallic biomaterials.","Additive manufacturing; Multi-material; Metal; Biomaterial; Bone implant","en","review","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:339d3ff2-e580-485c-9ba4-6eb6813d05ee","http://resolver.tudelft.nl/uuid:339d3ff2-e580-485c-9ba4-6eb6813d05ee","How Does Team Composition Affect Knowledge Gain of Users in Collaborative Web Search?","Xu, Luyan (Renmin University of China); Zhou, Xuan (East China Normal University); Gadiraju, Ujwal (TU Delft Web Information Systems)","","2020","Studies in searching as learning (SAL) have revealed that user knowledge gain not only manifests over a long-term learning period, but also occurs in single short-term web search sessions. Though prior works have shown that the knowledge gain of collaborators can be influenced by user demographics and searching strategies in long-term collaborative learning, little is known about the effect of these factors on user knowledge gain in short-term collaborative web search. In this paper, we present a study addressing the knowledge gain of user pairs in single collaborative web search sessions. Using crowdsourcing we recruited 454 unique users (227 random pairs), who then collaboratively worked on informational search tasks spanning 10 different topics and information needs. We investigated how users’ demographics and traits, and the interaction between these factors could influence their knowledge gain. We found that in contrast to offline collaboration cases, user demographics such as gender, age, etc. do not significantly effect users’ knowledge gain in collaborative web search sessions. Instead, our results highlight the presence of labor division of queries and particular interaction patterns in communication that facilitate knowledge gain in user pairs. Based on these findings, we propose a multiple linear regression model to predict the knowledge gain of users in collaborative web search sessions from the perspective of team composition.","Collaborative web search; Knowledge gain; Team composition; Search as learning; Crowdsourcing; User study","en","conference paper","Association for Computing Machinery (ACM)","","","","","Virtual/online event due to COVID-19 Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2021-11-08","","","Web Information Systems","","",""
"uuid:22b72435-96fa-4fc2-a34a-3c0d05ac2a19","http://resolver.tudelft.nl/uuid:22b72435-96fa-4fc2-a34a-3c0d05ac2a19","A 33-ppm/°C 240-nW 40-nm CMOS Wakeup Timer Based on a Bang-Bang Digital-Intensive Frequency-Locked-Loop for IoT Applications","Ding, Ming (Stichting IMEC Nederland); Zhou, Zhihao (SiTime; Student TU Delft); Traferro, Stefano (Stichting IMEC Nederland); Liu, Yao Hong (Stichting IMEC Nederland); Bachmann, Christian (Stichting IMEC Nederland); Sebastiano, F. (TU Delft (OLD)Applied Quantum Architectures)","","2020","This paper presents a wakeup timer in 40-nm CMOS for Internet-of-Things (IoT) applications based on a bang-bang Digital-intensive Frequency-Locked Loop (DFLL). A self-biased Σ Δ Digitally Controlled Oscillator (DCO) is locked to an RC time constant via a feedback loop consisting of a single-bit chopped comparator and a digital loop filter, thus maximizing the use of digital circuits while keeping only the RC network and the comparator as the sole analog blocks. Analysis and behavior level simulations of the DFLL have been carried out to guide the optimization of the long-term stability and frequency accuracy of the timer. High frequency accuracy and a 10× enhancement of long-term stability is achieved by the adoption of chopping to reduce the effect of comparator offset and 1/f noise and by the use of Σ Δ modulation to improve the DCO resolution. Such highly digitized architecture fully exploits the advantages of advanced CMOS processes, thus enabling operation down to 0.7 V and a small area (0.07 mm2). The proposed timer achieves the excellent energy efficiency (0.57 pJ/cycle at 417 kHz at 0.8-V supply) over prior art while keeping excellent on-par long-term stability (Allan deviation floor < 20 ppm) and temperature stability (33 ppm°Cat 0.8-V supply).","Digital-intensive; Frequency locked-loop; internet of things; Low-power; Oscillator; Wakeup timer","en","journal article","","","","","","Accepted Author Manuscript","","","","","(OLD)Applied Quantum Architectures","","",""
"uuid:7f0ae54b-520f-43b7-84a1-839559423792","http://resolver.tudelft.nl/uuid:7f0ae54b-520f-43b7-84a1-839559423792","Hypericin: Source, Determination, Separation, and Properties","Zhang, Jie (Chongqing Technology and Business University); Gao, Ling (Chongqing Technology and Business University); Hu, Jie (Chongqing Technology and Business University); Wang, Chongjun (Chongqing Technology and Business University); Hagedoorn, P.L. (TU Delft BT/Biocatalysis); Li, Ning (Chongqing Technology and Business University); Zhou, Xing (Chongqing Academy of Chinese Materia Medica, Chongqing)","","2020","Hypericin is a naturally occurring compound synthesized by certain species of the genus Hypericum, with various pharmacological effects. It is used as a natural photosensitizing agent with great potential in photodynamic therapy. This review discusses the latest results about the biosynthetic pathways and chemical synthetic routes to obtain hypericin. Although many analysis methods can be used for the determination of hypericin purity, HPLC has become the method of choice due to its fast and sensitive analyses. The extraction and purification of hypericin are also described. Hypericin can be used as a photosensitizer due to a large and active π-electron conjugated system in its structure. Medical applications of hypericin are not easy due to several unsolved practical problems, which include hypericin phototoxicity, poor solubility in water, and extreme sensitivity to light, heat, and pH.","extraction; Hypericin; photosensitivity; solubility; stability; synthesis","en","journal article","","","","","","","","","","","BT/Biocatalysis","","",""
"uuid:0fdf7c19-c084-469d-9a14-e21cbdf4e1ea","http://resolver.tudelft.nl/uuid:0fdf7c19-c084-469d-9a14-e21cbdf4e1ea","Indoline Catalyzed Acylhydrazone/Oxime Condensation under Neutral Aqueous Conditions","Zhou, Yuntao (Tsinghua University); Piergentili, I. (TU Delft ChemE/Advanced Soft Matter); Hong, Jennifer (Student TU Delft); van der Helm, M. (TU Delft ChemE/Advanced Soft Matter); Macchione, M. (TU Delft ChemE/Advanced Soft Matter); Li, Y. (Tsinghua University); Eelkema, R. (TU Delft ChemE/Advanced Soft Matter); Luo, Sanzhong (Tsinghua University)","","2020","Acylhydrazones formation has been widely applied in materials science and biolabeling. However, their sluggish condensation rate under neutral conditions limits its application. Herein, indolines with electron-donating groups are reported as a new catalyst scaffold, which can catalyze acylhydrazone, hydrazone, and oxime formation via an iminium ion intermediate. This new type of catalyst showed up to 15-fold rate enhancement over the traditional aniline-catalyzed reaction at neutral conditions. The identified indoline catalyst was successfully applied in hydrogel formation.","","en","journal article","","","","","","","","2021-07-29","","","ChemE/Advanced Soft Matter","","",""
"uuid:7f507d3e-89bd-46cf-81d8-73f5d430719d","http://resolver.tudelft.nl/uuid:7f507d3e-89bd-46cf-81d8-73f5d430719d","Detecting Emerging Challenges in Social Sidewalk Navigation","Vroon, Jered (TU Delft Internet of Things); Zhou, Y. (TU Delft Internet of Things); Rusak, Z. (TU Delft Internet of Things)","","2020","When mobile urban robots will share the sidewalk with people, the resulting interactions can cause unexpected undesirable outcomes to emerge – from people running away scared to people deliberately teasing and harassing such systems. How can we design such AI systems to aptly handle the unexpected? Directly anticipating and/or detecting these kinds of situations will inherently be unreliable; they are unexpected, after all. And yet, there exists a very clear signal for social slip-ups: the emotional response of people. We thus argue that such systems need to be imbued with a capacity to interpret the socio-emotional reactions to their own behavior.","Urban Robotics; Social Navigation; Social Signal Processing; Emergent Behavior","en","conference paper","","","","","","Curated by the organizers","","","","","Internet of Things","","",""
"uuid:aa383b7f-60a8-421f-8d30-6670e0559ca1","http://resolver.tudelft.nl/uuid:aa383b7f-60a8-421f-8d30-6670e0559ca1","Estimating reservoir permeability with borehole radar","Zhou, F. (TU Delft Applied Geophysics and Petrophysics; China University of Geosciences, Wuhan); Giannakis, Iraklis (University of West London); Giannopoulos, Antonios (University of Edinburgh); Holliger, Klaus (University of Lausanne); Slob, E.C. (TU Delft Applied Geophysics and Petrophysics)","","2020","In oil drilling, mud filtrate penetrates into porous formations and alters the compositions and properties of the pore fluids. This disturbs the logging signals and brings errors to reservoir evaluation. Drilling and logging engineers therefore deem mud invasion as undesired and attempt to eliminate its adverse effects. However, the mud-contaminated formation carries valuable information, notably with regard to its hydraulic properties. Typically, the invasion depth critically depends on the formation porosity and permeability. Therefore, if adequately characterized, mud invasion effects could be used for reservoir evaluation. To pursue this objective, we have applied borehole radar to measure mud invasion depth considering its high radial spatial resolution compared with conventional logging tools, which then allows us to estimate the reservoir permeability based on the acquired invasion depth. We investigate the feasibility of this strategy numerically through coupled electromagnetic and fluid modeling in an oil-bearing layer drilled using freshwater-based mud. Time-lapse logging is simulated to extract the signals reflected from the invasion front, and a dual-offset downhole antenna mode enables time-to-depth conversion to determine the invasion depth. Based on drilling, coring, and logging data, a quantitative interpretation chart is established, mapping the porosity, permeability, and initial water saturation into the invasion depth. The estimated permeability is in a good agreement with the actual formation permeability. Our results therefore suggest that borehole radar has significant potential to estimate permeability through mud invasion effects.","","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2020-12-10","","","Applied Geophysics and Petrophysics","","",""
"uuid:179b411d-947e-4570-8e49-86c211c63c9b","http://resolver.tudelft.nl/uuid:179b411d-947e-4570-8e49-86c211c63c9b","Harnessing Plasticity in an Amine-Borane as a Piezoelectric and Pyroelectric Flexible Film","Zhang, Yan (Central South University China; University of Bath); Hopkins, Margaret A. (University of Bath); Liptrot, David J. (University of Bath); Khanbareh, Hamideh (University of Bath); Groen, W.A. (TU Delft Aerospace Structures & Materials); Zhou, Xuefan (Central South University China); Zhang, Dou (Central South University China); Bao, Yinxiang (Central South University China); Zhou, Kechao (Central South University China); Bowen, Chris R. (University of Bath); Carbery, David R. (University of Bath)","","2020","We demonstrate that trimethylamine borane can exhibit desirable piezoelectric and pyroelectric properties. The material was shown to be able operate as a flexible film for both thermal sensing, thermal energy conversion and mechanical sensing with high open circuit voltages (>10 V). A piezoelectric coefficient of d33≈10–16 pC N−1, and pyroelectric coefficient of p≈25.8 μC m−2 K−1 were achieved after poling, with high pyroelectric figure of merits for sensing and harvesting, along with a relative permittivity of (Formula presented.) 6.3.","energy conversion; flexible films; main group elements; piezoelectricity; pyroelectricity","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2020-12-01","","Aerospace Structures & Materials","","","",""
"uuid:98a7cc04-f203-4851-b17e-ea3eb0dc88d0","http://resolver.tudelft.nl/uuid:98a7cc04-f203-4851-b17e-ea3eb0dc88d0","Urban travel time data cleaning and analysis for Automatic Number Plate Recognition","Li, Jie (Hunan University); van Zuylen, H.J. (TU Delft Transport and Planning; Hunan University; Southwest Jiaotong University); Deng, Yuansheng (Changsha Public Security Bureau); Zhou, Yun (Hunan University)","","2020","Data recorded by Automated Number Plate Recognition (ANPR) cameras can be used to determine several important traffic characteristics, such as real time travel time, travel time statistics, travel time reliability and OD matrices. In this paper ANPR data collected in Chinese city Changsha have been validated. Travel time extracted from ANPR data includes some outliers which are often caused by drivers who have an intermediate stop between two observation points or deviate from the straight route. Exceptional travel time reduces the validity of the estimation of the travel time and reliability. Firstly, the Rapid-Moving Window method is introduced to identify outliers. Afterwards, another method based on wavelet analysis is put forward to identify and remove the outliers in the travel time series. The wavelet analysis method is compared with the Rapid-Moving Window method and shows to be more accurate in outlier identification. The method for eliminating outliers in travel times can be implemented in real time to enhance the data quality for traffic network monitoring and management. After the removal of the outliers, the resulting travel times are used for the analysis of the relation between average travel time and standard deviation/skewness.","Automated Number Plate Recognition data; Data clearning; Travel time reliability; Wavelet analysis","en","journal article","","","","","","","","","","","Transport and Planning","","",""
"uuid:6e97a477-3a0c-43bb-8c75-9e628c071962","http://resolver.tudelft.nl/uuid:6e97a477-3a0c-43bb-8c75-9e628c071962","Markov-based solution for information diffusion on adaptive social networks","Liu, Chuang (Hangzhou Normal University); Zhou, Nan (Hangzhou Normal University); Zhan, X. (TU Delft Multimedia Computing); Sun, Gui-Quan (Shanxi University; North University of China); Zhang, Zi-Ke (Shanxi University; Hangzhou Normal University)","","2020","There is currently growing interest in modeling the information diffusion on social networks across multi-disciplines, including the prediction of the news popularity, the detection of the rumors and the influence of the epidemiological studies. Following the framework of the epidemic spreading, the information spreading models assume that information can be transmitted from the known individuals (infected) to the un-known individuals (susceptible) through the network interactions. During this process, individuals also always change their interactions which in turn will greatly influence the information spreading. In this work, we propose a mechanism considering the co-evolution between information states and network topology simultaneously, in which the information diffusion was executed as an SIS process and network topology evolved based on the adaptive assumption. The theoretical analyses based on the Markov approach were very consistent with simulation. Both simulation results and theoretical analyses indicated that the adaptive process, in which informed individuals would rewire the links between the informed neighbors to a random non-neighbor node, can enhance information diffusion (leading to much broader spreading). In addition, we obtained that two threshold values exist for the information diffusion on adaptive networks, i.e., if the information propagation probability is less than the first threshold, information cannot diffuse and dies out immediately; if the propagation probability is between the first and second threshold, information will spread to a finite range and die out gradually; and if the propagation probability is larger than the second threshold, information will diffuse to a certain size of population in the network. These results may shed some light on understanding the co-evolution between information diffusion and network topology.","Adaptive social networks; Co-evolution; Information spreading","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2020-11-01","","","Multimedia Computing","","",""
"uuid:01838298-7e74-4931-8f65-1d40877de4d9","http://resolver.tudelft.nl/uuid:01838298-7e74-4931-8f65-1d40877de4d9","Discrete element modelling of rubber-protected ballast performance subjected to direct shear test and cyclic loading","Guo, Y. (TU Delft Railway Engineering); Ji, Yameng (Beijing Jiaotong University); Zhou, Qiang (Beijing Jiaotong University); Markine, V.L. (TU Delft Railway Engineering); Jing, Guoqing (Beijing Jiaotong University)","","2020","The rubber-protected ballast (RPB) is made from natural ballast particles and crumb rubber particles. The crumb rubber is shredded waste tires. RPB was chosen to replace the ballast as it has higher resistance to breakage and abrasion. However, the static and dynamic performance of the RPB has not been confirmed yet. Towards this end, experimental tests and numerical simulations were utilized to study the feasibility of RPB application. Direct shear tests (DSTs) were performed and a DST model and three-sleeper track model with the discrete element method (DEM) were built. The shear strength, settlement, displacement, and acceleration of the RPB were studied. The results show that the RPB has the advantage of increasing the force (stress) distribution and that the smaller crumb rubber size was more suitable for replacing the ballast particles.","Ballast degradation; DEM; Dynamic performance; Railway ballast; RPB","en","journal article","","","","","","","","","","","Railway Engineering","","",""
"uuid:9c48a6a8-5615-4848-8799-738a84baca07","http://resolver.tudelft.nl/uuid:9c48a6a8-5615-4848-8799-738a84baca07","Revealing the Impact of Space-Charge Layers on the Li-Ion Transport in All-Solid-State Batteries","Cheng, Zhu (Nanjing University); Liu, M. (TU Delft RST/Storage of Electrochemical Energy); Ganapathy, S. (TU Delft RID/TS/Instrumenten groep); Li, Z. (TU Delft RST/Storage of Electrochemical Energy); Zhang, Xiaoyu (Nanjing University); He, Ping (Nanjing University); Zhou, Haoshen (Nanjing University; National Institute of Advanced Industrial Science and Technology (AIST)); Wagemaker, M. (TU Delft RST/Storage of Electrochemical Energy); Li, Chau (Nanjing University)","","2020","The influence of space-charge layers on the ionic charge transport over cathode-solid electrolyte interfaces in all-solid-state batteries remains unclear because of the difficulty to unravel it from other contributions to the ion transport over the interfaces. Here, we reveal the effect of the space-charge layers by systematically tuning the space-charge layer on and off between Li xV 2O 5 and Li 1.5Al 0.5Ge 1.5(PO 3) 4 (LAGP), by changing the Li xV 2O 5 potential and selectively measuring the ion transport over the interface by two-dimensional (2D) NMR exchange. The activation energy is demonstrated to be 0.315 eV for lithium-ion exchange over the space-charge-free interface, which increases dramatically to 0.515 eV for the interface with a space-charge layer. Comparison with a space-charge model indicates that the charge distribution due to the space-charge layer is responsible for the increased interface resistance. Thereby, the present work provides selective and quantitative insight into the effect of space-charge layers over electrode-electrolyte interfaces on ionic transport.","2D exchange NMR; interfaces; LAGP; Li-ion diffusion; LiVO; solid-state batteries; space-charge layers","en","journal article","","","","","","","","2021-06-17","","","RST/Storage of Electrochemical Energy","","",""
"uuid:5ef3f96b-3441-4955-9f27-7bd2340860dc","http://resolver.tudelft.nl/uuid:5ef3f96b-3441-4955-9f27-7bd2340860dc","Pyrophosphate Phosphor Solid Solution with High Quantum Efficiency and Thermal Stability for Efficient LED Lighting","Zhong, Yuan (Hunan Agricultural University); Xia, Mao (Hunan Agricultural University); Chen, Zhi (Hunan Agricultural University); Gao, Peixing (Hunan Agricultural University); Hintzen, H.T.J.M. (TU Delft RST/Luminescence Materials); Wong, Wai Yeung (The Hong Kong Polytechnic University); Wang, Jing (Sun Yat-sen University); Zhou, Zhi (Hunan Agricultural University)","","2020","Phosphors with high quantum efficiency and thermal stability are greatly desired for lighting industries. Based on the design strategy of solid solution, a series of deep-blue-emitting phosphors (Sr0.99-xBax)2P2O7:0.02Eu2+ (SBxPE x = 0–0.5) are developed. Upon excitation at 350 nm, the optimized SB0.3PE phosphor shows a relatively narrow full width at half maximum (FWHM = 32.7 nm) peaking at 420 nm, which matches well with the plant absorption in blue region. Moreover, this phosphor exhibits obvious enhancement of internal quantum efficiency (IQE) (from 74% to 100%) and thermal stability (from 88% to 108% of peak intensity and from 99% to 124% of integrated area intensity at 150°C) compared with the pristine one. The white LED devices using SB0.3PE as deep-blue-emitting component show good electronic properties, indicating that SB0.3PE is promising to be used in plant growth lighting, white LEDs, and other photoelectric applications. Inorganic Materials; Materials Application; Optical Materials","Inorganic Materials; Materials Application; Optical Materials","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:b03610fa-65ae-4561-8059-3089fd2fbe15","http://resolver.tudelft.nl/uuid:b03610fa-65ae-4561-8059-3089fd2fbe15","Construction of three-dimensional extrusion limit diagram for magnesium alloy using artificial neural network and its validation","Bai, Shengwen (Tsinghua University); Fang, Gang (Tsinghua University); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2020","Conventional extrusion limit diagram (ELD) involves only two extrusion process variables and as such it does not account for the combined effects of multiple process parameters on the extrusion process with respect to pressure requirement and extrudate temperature. Attempts were made in the present research to construct three-dimensional (3D) ELD for a magnesium alloy in the space of initial billet temperature, extrusion ratio and extrusion speed. A method to build 3D ELD by integrating finite element (FE) simulations, extrusion experiments and artificial neural networks (ANN) was developed. In addition to initial billet temperature, extrusion ratio and extrusion speed, the temperature difference between the extrusion tooling and billet, the size of the billet and the shape complexity of the extrudate were taken as the additional process variables and integrated into the equivalent initial billet temperature, extrusion ratio and extrusion speed. The FE simulations, verified by performing extrusion experiments to produce magnesium alloy rods, were used to generate datasets for training the ANN. The ANN then predicted the peak values of extrusion pressure and extrudate temperature over a wider range of extrusion conditions, based on which a 3D ELD for the magnesium alloy was constructed. The 3D ELD was finally validated by performing extrusion experiments to produce magnesium alloy tubes. The results demonstrated that the constructed 3D ELD was reliable and able to provide guidelines for the selection of appropriate extrusion conditions.","Artificial neural networks; Extrusion; Extrusion limit diagram; Hot shortness; Magnesium","en","journal article","","","","","","Accepted Author Manuscript","","2021-08-19","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:9774d1c5-df2e-4388-9db3-0dd3ea5302d6","http://resolver.tudelft.nl/uuid:9774d1c5-df2e-4388-9db3-0dd3ea5302d6","Additively manufactured biodegradable porous zinc","Li, Y. (TU Delft Biomaterials & Tissue Biomechanics); Pavanram, P. (University Hospital RWTH Aachen); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Lietaert, K. (Katholieke Universiteit Leuven; 3D Systems – LayerWise NV); Taheri, P. (TU Delft (OLD) MSE-6); Li, W. (TU Delft (OLD) MSE-3); San, H. (TU Delft Biomaterials & Tissue Biomechanics; Harbin Institute of Technology); Leeflang, M.A. (TU Delft Biomaterials & Tissue Biomechanics); Mol, J.M.C. (TU Delft (OLD) MSE-6); Jahr, H. (Maastricht UMC; University Hospital RWTH Aachen); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2020","Additively manufacturing (AM) opens up the possibility for biodegradable metals to possess uniquely combined characteristics that are desired for bone substitution, including bone-mimicking mechanical properties, topologically ordered porous structure, pore interconnectivity and biodegradability. Zinc is considered to be one of the promising biomaterials with respect to biodegradation rate and biocompatibility. However, no information regarding the biodegradability and biocompatibility of topologically ordered AM porous zinc is yet available. Here, we applied powder bed fusion to fabricate porous zinc with a topologically ordered diamond structure. An integrative study was conducted on the static and dynamic biodegradation behavior (in vitro, up to 4 weeks), evolution of mechanical properties with increasing immersion time, electrochemical performance, and biocompatibility of the AM porous zinc. The specimens lost 7.8% of their weight after 4 weeks of dynamic immersion in a revised simulated body fluid. The mechanisms of biodegradation were site-dependent and differed from the top of the specimens to the bottom. During the whole in vitro immersion time of 4 weeks, the elastic modulus values of the AM porous zinc (E = 700–1000 MPa) even increased and remained within the scope of those of cancellous bone. Indirect cytotoxicity revealed good cellular activity up to 72 h according to ISO 10,993–5 and -12. Live-dead staining confirmed good viability of MG-63 cells cultured on the surface of the AM porous zinc. These important findings could open up unprecedented opportunities for the development of multifunctional bone substituting materials that will enable reconstruction and regeneration of critical-size load-bearing bone defects. Statement of significance: No information regarding the biodegradability and biocompatibility of topologically ordered AM porous zinc is available. We applied selective laser melting to fabricate topologically ordered porous zinc and conducted a comprehensive study on the biodegradation behavior, electrochemical performance, time-dependent mechanical properties, and biocompatibility of the scaffolds. The specimens lost 7.8% of their weight after4 weeks dynamic biodegradation while their mechanical properties surprisingly increased after 4 weeks. Indirect cytotoxicity revealed good cellular activity up to 72 h. Intimate contact between MG-63 cells and the scaffolds was also observed. These important findings could open up unprecedented opportunities for the development of multifunctional bone substituting materials that mimic bone properties and enable full regeneration of critical-size load-bearing bony defects.","Additive manufacturing; Biocompatibility; Biodegradation; Mechanical property; scaffold; Zinc","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2020-04-28","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:96f3645d-7bd5-4a3b-bfa5-b58ec0f02f40","http://resolver.tudelft.nl/uuid:96f3645d-7bd5-4a3b-bfa5-b58ec0f02f40","LiDAR-guided dense matching for detecting changes and updating of buildings in Airborne LiDAR data","Zhou, K. (TU Delft Optical and Laser Remote Sensing); Lindenbergh, R.C. (TU Delft Optical and Laser Remote Sensing); Gorte, Ben (University of New South Wales); Zlatanova, S. (University of New South Wales)","","2020","Change detection is essential to keep 3D city models up-to-date. LiDAR data with high accuracy are used to create 3D city models. However, updating LiDAR data at state or nation level often takes around a decade. Very high resolution (VHR) stereo images, with often yearly updating rate and dense 3D information, provide an option for validating and updating LiDAR data. However, the 3D information in both data sources has quality problems. LiDAR point clouds are sparse and irregularly spaced, and have mixed returns near building edges, while 3D information extracted from stereo images are affected by shadow and low texture. This research proposes LiDAR-guided dense matching to address these problems explicitly for detecting accurate building changes. Data sparsity and irregular spacing is addressed by densifying LiDAR points in a form of a digital surface model (DSM). Instead of applying interpolation with associated edge problems due to mixed returns, three candidate DSMs are created by linking each DSM pixel to up to three planes as identified in segmented and triangulated LiDAR data. The candidate DSMs limit the disparity search space for dense matching, addressing low texture and shadow problems in images. Through edge-aware dense matching, the detailed building edge information in stereo pairs determine the optimal heights to address LiDAR edge problem. Changes are detected where corresponding pixels from dense matching have large color differences. Due to homogeneous surroundings and shadows, only partial changes are initially detected. A second hierarchical dense matching step is employed to complete changes and update 3D information by propagating initial partial changes iteratively. The proposed method is applied on data from two cities, Amersfoort and Assen, the Netherlands, with around 1200 existing buildings. In both areas, the method successfully verifies unchanged buildings while detecting minimum changes of 2×2×2m3. New and removed building detection in Amersfoort both have a F1 score of over 0.8, both in pixel and object evaluation, while F1 scores in Assen are over 0.9 for both categories. The experiments also show that the proposed method outperforms two well-known change detection methods in terms of verifying unchanged buildings and detecting small changes simultaneously.","3D city model; Building; Change detection; Dense matching; LiDAR data; VHR images","en","journal article","","","","","","Accepted Author Manuscript","","2022-03-04","","","Optical and Laser Remote Sensing","","",""
"uuid:602e566b-8ce3-45de-91aa-9f240ae4245e","http://resolver.tudelft.nl/uuid:602e566b-8ce3-45de-91aa-9f240ae4245e","A novel asynchronous-pouring-construction technology for prestressed concrete box girder bridges with corrugated steel webs","He, Jun (Changsha University of Science and Technology; Heriot-Watt University); Li, Xiang (Changsha University of Science and Technology); Li, Chuanxi (Changsha University of Science and Technology); Correia, José A.F.O. (Universidade do Porto); Xin, H. (TU Delft Steel & Composite Structures; Xi’an Jiaotong University); Zhou, Man (Central South University)","","2020","Owing to the superior mechanical performance and material efficiency, the combination of prestressed concrete (PC) slabs and corrugated steel webs (CSW) as PC girder with CSWs (PCGCSW) is extensively applied to railway and highway bridges. To overcome the shortcomings of traditional balanced cantilever construction (TBCC) of PCGCSW, reduce environmental impact, and promote sustainable construction, a novel asynchronous-pouring-construction (APC) technology is introduced in this paper. This improved method makes full use of the excellent shear capacity of the corrugated steel webs (CSWs) to support the hanging basket, increases the construction platforms to accelerate the construction speed. Based on a practical project of a long-span composite box girder bridge with CSWs in China, the construction process of the APC method is systematically introduced, and the structural safety and environmental sustainability of such bridge using APC technology are evaluated and compared with that using TBCC. The comparison results indicate that APC method can reduce the compressive stress of top concrete slab, but slightly increase the shear stress and deflection during the cantilever construction stage because the hanging basket is directly supported by CSWs. Besides, the weight of the improved handing basket in APC technology is reduced up to half in comparison that in TBCC. Accordingly, the APC technology saves a lot of energy consumption, reduces huge CO2 emissions for construction equipment, and shorts construction period. Therefore, the utilization of APRC technology can ensure the bridge's safety and reliability, effectively accelerate construction speed, reduce the construction load, decrease the environmental pollution, and save the engineering cost, which can be regarded as a sustainable and environmental-friendly construction method for composite bridges with CSWs.","Asynchronous-Pouring-Construction (APC) Technology; CSWs; Environmental impact; PC box girder bridge; Structural performance; Sustainable construction","en","journal article","","","","","","","","","","","Steel & Composite Structures","","",""
"uuid:d563d9cc-7296-42d9-9853-b2d8a5ae2756","http://resolver.tudelft.nl/uuid:d563d9cc-7296-42d9-9853-b2d8a5ae2756","An integrated methodology for the supply reliability analysis of multi-product pipeline systems under pumps failure","Zhou, X. (TU Delft Safety and Security Science; China University of Petroleum - Beijing); van Gelder, P.H.A.J.M. (TU Delft Safety and Security Science); Liang, Yongtu (China University of Petroleum - Beijing); Zhang, Haoran (University of Tokyo)","","2020","As the main way for the long-distance transportation of refined products, multi-products pipelines are of vital importance to the regional energy security. The supply reliability evaluation of multi-product pipeline systems can improve the effective response to unexpected disruptions and guarantee the reliable oil supply. Based on reliability theory and pipeline scheduling method, an integrated supply reliability evaluation methodology for multi-product pipeline systems is proposed in this paper and the pumps failure, of which influence is the most complex, is focused on. In the methodology, the discrete-time Markov process is adopted to describe the stochastic failure and the Monte Carlo method is used to simulate the system states transition. With the pipeline flowrate upper limits under various pumps failure scenarios optimized in advance, the maximum supply capacity to the downstream markets in each trial is calculated by the pipeline scheduling model. Three indicators are also developed to analyze the pipeline supply reliability from the holistic and individual perspectives. At last, the methodology application is performed on a real-world multi-product pipeline system in China and the supply reliability is analyzed in detail according to the simulation results. It is proved to provide a practical method for the emergency response decision-making and loss prevention.","Evaluation indicators; Multi-product pipeline; Pipeline scheduling method; Pumps failure; Stochastic process simulation; Supply reliability analysis","en","journal article","","","","","","","","2022-08-22","","","Safety and Security Science","","",""
"uuid:7921f0a0-a664-4104-9728-4e88b2975b77","http://resolver.tudelft.nl/uuid:7921f0a0-a664-4104-9728-4e88b2975b77","Confidence curves for change points in hydrometeorological time series","Zhou, C. (TU Delft Water Resources); van Nooijen, R.R.P. (TU Delft Water Resources); Kolechkina, A.G. (TU Delft Team Bart De Schutter); van de Giesen, N.C. (TU Delft Water Resources)","","2020","In this paper, a method based on Approximate Empirical likelihood ratio and a Deviance function combined with bootstrapping (AED-BP) is proposed to construct a confidence curve for the location of a change point. The method is compared with a method based on parametric Profile Likelihood and a Deviance function combined with Monte Carlo simulation (PLD-MC). A confidence curve provides a representation of the uncertainty in the outcome of the change point analysis. To evaluate the practical usability of confidence curves constructed by AED-BP, its properties were examined and its performance was compared to that of PLD-MC. The methods were applied to both synthetic and real data. Synthetic data were generated from three parametric distributions: Fréchet with a constant shape parameter, log-normal, and gamma distributions. The real data are the hydrometeorological data analysed in other studies. The change points found in the original publications are used as a reference in this present paper. The results show that AED-BP has a performance that is similar to PLD-MC, but has an advantage in that it is not necessary to select a distribution family for the data. The AED-BP results on the Annual Maximum Runoff series for the stations Yichang and Hankou along the Yangtze river are among the first that show a possible effect of the presence of the Three Gorges dam.","Approximate empirical likelihood ratio; Change point detection; Confidence curves; Confidence sets; Parametric likelihood ratio; Similarity index","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2021-03-11","","","Water Resources","","",""
"uuid:daa936d2-49bf-4fa3-b141-6876b261d0df","http://resolver.tudelft.nl/uuid:daa936d2-49bf-4fa3-b141-6876b261d0df","Solvent-cast 3D printing of magnesium scaffolds","Dong, J. (TU Delft Biomaterials & Tissue Biomechanics); Li, Y. (TU Delft Biomaterials & Tissue Biomechanics); Lin, P. (TU Delft Pavement Engineering); Leeflang, M.A. (TU Delft Biomaterials & Tissue Biomechanics); van Asperen, S. (TU Delft (OLD) MSE-3); Yu, K. (TU Delft BN/Marie-Eve Aubin-Tam Lab; Kavli institute of nanoscience Delft); Tümer, N. (TU Delft Biomaterials & Tissue Biomechanics); Norder, B. (TU Delft ChemE/O&O groep); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2020","Biodegradable porous magnesium (Mg) scaffolds are promising for application in the regeneration of critical-sized bone defects. Although additive manufacturing (AM) carries the promise of offering unique opportunities to fabricate porous Mg scaffolds, current attempts to apply the AM approach to fabricating Mg scaffolds have encountered some crucial issues, such as those related to safety in operation and to the difficulties in composition control. In this paper, we present a room-temperature extrusion-based AM method for the fabrication of topologically ordered porous Mg scaffolds. It is composed of three steps, namely (i) preparing a Mg powder loaded ink with desired rheological properties, (ii) solvent-cast 3D printing (SC-3DP) of the ink to form scaffolds with 0 °/ 90 °/ 0 ° layers, and (iii) debinding and sintering to remove the binder in the ink and then get Mg powder particles bonded by applying a liquid-phase sintering strategy. A rheological analysis of the prepared inks with 54, 58 and 62 vol% Mg powder loading was performed to reveal their viscoelastic properties. Thermal-gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), carbon/sulfur analysis and scanning electron microscopy (SEM) indicated the possibilities of debinding and sintering at one single step for fabricating pure Mg scaffolds with high fidelity and densification. The resulting scaffolds with high porosity contained hierarchical and interconnected pores. This study, for the first time, demonstrated that the SC-3DP technique presents unprecedented possibilities to fabricate Mg-based porous scaffolds that have the potential to be used as a bone-substituting material. Statement of Significance: Biodegradable porous magnesium scaffolds are promising for application in the regeneration of critical-sized bone defects. Although additive manufacturing (AM) carries the promise of offering unique opportunities to fabricate porous magnesium scaffolds, current attempts to apply the AM approach to fabricating magnesium scaffolds still have some crucial limitations. This study demonstrated that the solvent-cast 3D printing technique presents unprecedented possibilities to fabricate Mg-based porous scaffolds. The judicious chosen of formulated binder system allowed for the negligible binder residue after debinding and the short-time liquid-phase sintering strategy led to a great success in sintering pure magnesium scaffolds. The resulting scaffolds with hierarchical and interconnected pores have great potential to be used as a bone-substituting material.","Additive manufacturing; Magnesium; Scaffold; Sintering; Solvent-cast","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:11b56ca6-f21a-437b-9437-85e8d9b4cfc7","http://resolver.tudelft.nl/uuid:11b56ca6-f21a-437b-9437-85e8d9b4cfc7","Impacts of wind and current on ship behavior in ports and waterways: A quantitative analysis based on AIS data","Zhou, Y. (TU Delft Rivers, Ports, Waterways and Dredging Engineering); Daamen, W. (TU Delft Transport and Planning); Vellinga, T. (TU Delft Rivers, Ports, Waterways and Dredging Engineering); Hoogendoorn, S.P. (TU Delft Transport and Planning)","","2020","In ports and waterways, the impacts of external navigational factors may lead to serious incidents due to limited space for ship maneuvering. Using nautical traffic models, these incidents can be predicted in advance. In current studies of nautical traffic models, the impacts of wind and current on ship behavior are seldom considered when modeling the ship behavior in a port area. The numerical maneuvering models simulate the individual ship behavior under such impacts by calculating the hydrodynamic forces working on the ship's hull. However, the input, maneuvering particulars of individual ships, are not available in ports. In order to fill the knowledge gap of estimating ship behavior under external impacts without detailed ship maneuvering information, the impacts of wind and current on the observed dynamic ship behavior (speed over ground and leeway and drift angle) in ports and waterways have been investigated by analyzing Automatic Identification System data (showing ship paths over time) and the meteorological and hydrological data collected from the port of Rotterdam. The relation between unhindered speed variation and ship size is revealed. The regression analysis results on ships with similar size indicate the differences between wind and current impacts. Especially for small ships, the current impact on speed over ground outweighs the wind, while the wind influences the leeway and drift angle more than the current. Based on the quantified impact variation over ship size, the proposed impact mechanism explains the variance of speed over ground and leeway and drift angle. Some conventional sailing habits based on good seamanship, such as a series of small-angle alterations rather than direct turning at waypoints, are also revealed by the statistical analyses. Considering the variation of wind and current conditions in the study area, the analysis result provides generic quantitative insights into the wind and current impacts on the individual behavior of ships of different sizes. These mathematical formulations can be adopted in a microscopic nautical traffic model to include the impacts of external conditions.","AIS data; Current impact; External disturbance; Ports and waterways; Ship behavior; Wind impact","en","journal article","","","","","","","","","","Transport and Planning","Rivers, Ports, Waterways and Dredging Engineering","","",""
"uuid:d75bbd1f-1072-41b9-986a-772806f83735","http://resolver.tudelft.nl/uuid:d75bbd1f-1072-41b9-986a-772806f83735","Site Occupancies, VUV-UV-vis Photoluminescence, and X-ray Radioluminescence of Eu2+-Doped RbBaPO4","Zhou, Rongfu (Sun Yat-sen University); Ma, Fengkai (Sun Yat-sen University); Su, Fang (Sun Yat-sen University); Ou, Yiyi (Sun Yat-sen University); Qi, Zeming (University of Science and Technology of China); Zhang, Jianhui (Sun Yat-sen University); Huang, Yan (Institute of High Energy Physics Chinese Academy of Science); Dorenbos, P. (TU Delft RST/Luminescence Materials); Liang, Hongbin (Sun Yat-sen University)","","2020","RbBaPO4:Eu2+ phosphors have been prepared by a high-temperature solid-state reaction method, and the structure was determined by Rietveld refinement based on powder X-ray diffraction (P-XRD) data. Their VUV-UV-vis photoluminescence properties are systematically investigated with three objectives: (1) based on low-temperature spectra, we clarify the site occupancies of Eu2+, and demonstrate that the doublet emission bands at ∼406 and ∼431 nm originate from Eu2+ in Ba2+ [Eu2+(I)] and Rb+ [Eu2+(II)] sites, respectively; (2) an electron-vibrational interaction (EVI) analysis is conducted to estimate the Huang-Rhys factors, the zero-phonon lines (ZPLs) and the Stokes shifts of Eu2+ in Rb+ and Ba2+ sites; (3) the studies on luminescence decay of Eu2+(I) reveal that dipole-dipole interaction is mainly responsible for the energy transfer from Eu2+(I) to Eu2+(II), and the energy migration between Eu2+(I) is weak. Finally, the X-ray excited luminescence (XEL) spectrum indicates that the light yield of the sample RbBa0.995Eu0.005PO4 is ∼17700 ph/MeV, showing its potential application in X-ray detecting.","","en","journal article","","","","","","Accepted Author Manuscript","","2021-11-12","","","RST/Luminescence Materials","","",""
"uuid:55481e5d-a8dd-4847-9949-af31997fb865","http://resolver.tudelft.nl/uuid:55481e5d-a8dd-4847-9949-af31997fb865","Mapping land use land cover transitions at different spatiotemporal scales in West Africa","Barnieh, Beatrice Asenso (Chinese Academy of Sciences; University of Chinese Academy of Sciences); Jia, Li (Chinese Academy of Sciences); Menenti, M. (TU Delft Optical and Laser Remote Sensing; Chinese Academy of Sciences); Zhou, Jie (Central China Normal University); Zeng, Yelong (Chinese Academy of Sciences; University of Chinese Academy of Sciences)","","2020","Post‐classification change detection was applied to examine the nature of Land Use Land Cover (LULC) transitions in West Africa in three time intervals (1975–2000, 2000–2013, and 1975– 2013). Detailed analyses at hotspots coupled with comparison of LULC transitions in the humid and arid regions were undertaken. Climate and anthropic drivers of environmental change were disentangled by the LULC transitions analyses. The results indicated that human‐managed LULC types have replaced the natural LULC types. The total vegetation cover declined by −1.6%. Massive net gains in croplands (107.8%) and settlements (140%) at the expense of natural vegetation were detected in the entire period (1975–2013). Settlements expanded in parallel with cropland, which suggests the effort to increase food production to support the increasing population. Expansion of artificial water bodies were detected in the humid regions during the period of 1975–2000. Nonetheless, shrinking of water bodies due to encroachment by wetlands and other vegetation was observed in the arid regions, coupled with net loss in the whole of West Africa. The results indicate deforestation and degradation of natural vegetation and water resources in West Africa. Underlying anthropic drivers and a combination of anthropic and climate drivers were detected. LULC transitions in West Africa are location specific and have both positive and negative implications on the environment. The transitions indicate how processes at the local level, driven by human activities, lead to changes at the continental level and may contribute to global environmental change.","Anthropic; Arid region; Climate; Humid region; LULC transitions; West Africa","en","journal article","","","","","","","","","","","Optical and Laser Remote Sensing","","",""
"uuid:7635c325-91e9-4459-84b3-1ce87f7359a5","http://resolver.tudelft.nl/uuid:7635c325-91e9-4459-84b3-1ce87f7359a5","The inactivation mechanism of chemical disinfection against SARS-CoV-2: From MD and DFT perspectives","Tan, C. (TU Delft Electronic Components, Technology and Materials; Southern University of Science and Technology; Shenzhen Institute of Wide-bandgap Semiconductors); Gao, Chenshan (Chongqing University); Zhou, Quan (Chongqing University); van Driel, W.D. (TU Delft Electronic Components, Technology and Materials); Ye, H. (Shenzhen Institute of Wide-bandgap Semiconductors; Southern University of Science and Technology; Ministry of Education, Shenzhen); Zhang, Kouchi (TU Delft Electronic Components, Technology and Materials)","","2020","Exploring effective disinfection methods and understanding their mechanisms on the new coronavirus is becoming more active due to the outbreak of novel coronavirus pneumonia (COVID-19) caused by severe acute respiratory coronavirus 2 (SARS-CoV-2). By combining molecular dynamics and first-principles calculations, we investigate the interaction mechanism of chemical agents with 3CL hydrolase of SARS-CoV-2. The radial distribution functions indicate that the biocidal ingredients are sensitive to the unsaturated oxygen atoms of 3CL hydrolase and their interactions remarkably depend on the concentration of the biocidal ingredients. Besides, we find that the adsorption performance of the active ingredients for the unsaturated oxygen atoms is superior to other styles of atoms. These computational results not only decipher the inactivation mechanism of chemical agents against SARS-CoV-2 from the molecule-level perspective, but also provide a theoretical basis for the development and application of new chemical methods with a high disinfection efficiency.","","en","journal article","","","","","","","","","","","Electronic Components, Technology and Materials","","",""
"uuid:76fa65e3-2ae3-4b49-9d4c-11c725fc99e0","http://resolver.tudelft.nl/uuid:76fa65e3-2ae3-4b49-9d4c-11c725fc99e0","Innovative Tissue-Engineered Strategies for Osteochondral Defect Repair and Regeneration: Current Progress and Challenges","Zhou, Liangbin (Chinese University of Hong Kong); van Osch, G.J.V.M. (TU Delft Biomaterials & Tissue Biomechanics; Erasmus MC); Malda, Jos (Universiteit Utrecht); Stoddart, Martin J. (AO Research Institute Davos, Davos); Lai, Yuxiao (Chinese Academy of Sciences); Richards, R. Geoff (AO Research Institute Davos, Davos); Ki-wai Ho, Kevin (Chinese University of Hong Kong); Qin, Ling (Chinese University of Hong Kong; Chinese Academy of Sciences)","","2020","Clinical treatments for the repair of osteochondral defects (OCD) are merely palliative, not completely curative, and thus enormously unfulfilled challenges. With the in-depth studies of biology, medicine, materials, and engineering technology, the conception of OCD repair and regeneration should be renewed. During the past decades, many innovative tissue-engineered approaches for repairing and regenerating damaged osteochondral units have been widely explored. Various scaffold-free and scaffold-based strategies, such as monophasic, biphasic, and currently fabricated multiphasic and gradient architectures have been proposed and evaluated. Meanwhile, progenitor cells and tissue-specific cells have also been intensively investigated in vivo as well as ex vivo. Concerning bioactive factors and drugs, they have been combined with scaffolds and/or living cells, and even released in a spatiotemporally controlled manner. Although tremendous progress has been achieved, further research and development (R&D) is needed to convert preclinical outcomes into clinical applications. Here, the osteochondral unit structure, its defect classifications, and diagnosis are summarized. Commonly used clinical reparative techniques, tissue-engineered strategies, emerging 3D-bioprinting technologies, and the status of their clinical applications are discussed. Existing challenges to translation are also discussed and potential solutions for future R&D directions are proposed.","clinical applications; osteochondral defect repair and regeneration; scaffolds; tissue-engineered strategies","en","review","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2021-04-26","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:d3924d09-0526-4005-803b-55acb03c69a4","http://resolver.tudelft.nl/uuid:d3924d09-0526-4005-803b-55acb03c69a4","Additively manufactured functionally graded biodegradable porous zinc","Li, Y. (TU Delft Biomaterials & Tissue Biomechanics); Pavanram, P. (University Hospital RWTH Aachen); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Lietaert, K. (Katholieke Universiteit Leuven; 3D Systems – LayerWise NV); Bobbert, F.S.L. (TU Delft Biomaterials & Tissue Biomechanics); Kubo, Yusuke (University Hospital RWTH Aachen); Leeflang, M.A. (TU Delft Biomaterials & Tissue Biomechanics); Jahr, H. (University Hospital RWTH Aachen; Maastricht UMC); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2020","Topological design provides additively manufactured (AM) biodegradable porous metallic biomaterials with a unique opportunity to adjust their biodegradation behavior and mechanical properties, thereby satisfying the requirements for ideal bone substitutes. However, no information is available yet concerning the effect of topological design on the performance of AM porous zinc (Zn) that outperforms Mg and Fe in biodegradation behavior. Here, we studied one functionally graded and two uniform AM porous Zn designs with diamond unit cell. Cylindrical specimens were fabricated from pure Zn powder by using a powder bed fusion technique, followed by a comprehensive study on their static and dynamic biodegradation behaviors, mechanical properties, permeability, and biocompatibility. Topological design, indeed, affected the biodegradation behavior of the specimens, as evidenced by 150% variations in biodegradation rate between the three different designs. After in vitro dynamic immersion for 28 days, the AM porous Zn had weight losses of 7-12%, relying on the topological design. The degradation rates satisfied the desired biodegradation time of 1-2 years for bone substitution. The mechanical properties of the biodegraded specimens of all the groups maintained within the range of those of cancellous bone. As opposed to the trends observed for other biodegradable porous metals, after 28 days of in vitro biodegradation, the yield strengths of the specimens of all the groups (σy = 7-14 MPa) increased consistently, as compared to those of the as-built specimens (σy = 4-11 MPa). Moreover, AM porous Zn showed excellent biocompatibility, given that the cellular activities in none of the groups differed from the Ti controls for up to 72 h. Using topological design of AM porous Zn for controlling its mechanical properties and degradation behavior is thus clearly promising, thereby rendering flexibility to the material to meet a variety of clinical requirements.","","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:a5715125-1fc7-4572-9091-0382c5aec688","http://resolver.tudelft.nl/uuid:a5715125-1fc7-4572-9091-0382c5aec688","Thermal energy recovery from chlorinated drinking water distribution systems: Effect on chlorine and microbial water and biofilm characteristics","Zhou, X. (TU Delft Sanitary Engineering; Zhejiang University); Ahmad, J.I. (TU Delft Sanitary Engineering; National University of Science and Technology (NUST)); van der Hoek, J.P. (TU Delft Sanitary Engineering; Waternet); Zhang, Kejia (Zhejiang University)","","2020","Thermal energy recovery from drinking water has a high potential in the application of sustainable building and industrial cooling. However, drinking water and biofilm microbial qualities should be concerned because the elevated water temperature after cold recovery may influence the microbial activities in water and biofilm phases in drinking water distribution systems (DWDSs). In this study, the effect of cold recovery on microbial qualities was investigated in a chlorinated DWDS. The chlorine decay was slight (1.1%–15.5%) due to a short contact time (~60 s) and was not affected by the cold recovery (p > 0.05). The concentrations of cellular ATP and intact cell numbers in the bulk water were partially inactivated by the residual chlorine, with the removal rates of 10.1%–16.2% and 22.4%–29.4%, respectively. The chlorine inactivation was probably promoted by heat exchangers but was not further enhanced by higher temperatures. The higher water temperature (25 °C) enhanced the growth of biofilm biomass on pipelines. Principle coordination analysis (PCoA) showed that the biofilms on the stainless steel plates of HEs and the plastic pipe inner surfaces had totally different community compositions. Elevated temperatures favored the growth of Pseudomonas spp. and Legionella spp. in the biofilm after cold recovery. The community functional predictions revealed more abundances of five human diseases (e.g. Staphylococcis aureus infection) and beta-lactam resistance pathways in the biofilms at higher temperature. Compared with a previous study with a non-chlorinated DWDS, chlorine dramatically reduced the biofilm biomass growth but raised the relative abundances of the chlorine-resistant genera (i.e. Pseudomonas and Sphingomonas) in bacterial communities.","Biofilm community structure; Chlorine; Cold recovery; Drinking water microbial activity; Functional prediction","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2020-11-15","","","Sanitary Engineering","","",""
"uuid:f50bd1f1-e48e-4c37-8ec1-7369f70af7e7","http://resolver.tudelft.nl/uuid:f50bd1f1-e48e-4c37-8ec1-7369f70af7e7","Pandemic programming: How COVID-19 affects software developers and how their organizations can help","Ralph, Paul (Dalhousie University); Baltes, Sebastian (University of Adelaide); Adisaputri, Gianisa (Dalhousie University); Torkar, Richard (Chalmers University of Technology; University of Gothenburg; Stellenbosch Institute for Advanced Study); Kovalenko, V.V. (JetBrains); Kalinowski, Marcos (Pontifical Catholic University of Rio de Janeiro); Novielli, Nicole (University of Bari Aldo Moro); Yoo, Shin (Korea Advanced Institute of Science and Technology); Devroey, Xavier (TU Delft Software Engineering); Tan, Xin (Peking University); Zhou, Minghui (Peking University); Turhan, Burak (Monash University; University of Oulu); Hoda, Rashina (Monash University); Hata, Hideaki (Nara Institute of Science and Technology); Robles, Gregorio (Universidad Rey Juan Carlos); Milani Fard, Amin (New York Institute of Technology); Alkadhi, Rana (King Saud University)","","2020","Context: As a novel coronavirus swept the world in early 2020, thousands of software developers began working from home. Many did so on short notice, under difficult and stressful conditions.
Objective: This study investigates the effects of the pandemic on developers’ wellbeing and productivity.
Method: A questionnaire survey was created mainly from existing, validated scales and translated into 12 languages. The data was analyzed using non-parametric inferential statistics and structural equation modeling.
Results: The questionnaire received 2225 usable responses from 53 countries. Factor analysis supported the validity of the scales and the structural model achieved a good fit (CFI = 0.961, RMSEA = 0.051, SRMR = 0.067). Confirmatory results include: (1) the pandemic has had a negative effect on developers’ wellbeing and productivity; (2) productivity and wellbeing are closely related; (3) disaster preparedness, fear related to the pandemic and home office ergonomics all affect wellbeing or productivity. Exploratory analysis suggests that: (1) women, parents and people with disabilities may be disproportionately affected; (2) different people need different kinds of support.
Conclusions: To improve employee productivity, software companies should focus on maximizing employee wellbeing and improving the ergonomics of employees’ home offices. Women, parents and disabled persons may require extra support.","COVID-19; Crisis management; Disaster management; Emergency management; Pandemic; Productivity; Questionnaire; Software development; Structural equation modeling; Wellbeing; Work from home","en","journal article","","","","","","","","","","","Software Engineering","","",""
"uuid:90bd425f-220a-42d2-ba06-4c6091b77db1","http://resolver.tudelft.nl/uuid:90bd425f-220a-42d2-ba06-4c6091b77db1","TaskGenie: Crowd-Powered Task Generation for Struggling Search","Xu, Luyan (Renmin University of China); Zhou, Xuan (East China Normal University); Gadiraju, Ujwal (TU Delft Web Information Systems)","Huang, Zhisheng (editor); Beek, Wouter (editor); Wang, Hua (editor); Zhang, Yanchun (editor); Zhou, Rui (editor)","2020","Search tasks provide a medium for the evaluation of system performance and the underlying analytical aspects of IR systems. Researchers have recently developed new interfaces or mechanisms to support vague information needs and struggling search. However, little attention has been paid to the generation of a unified task set for evaluation and comparison of search engine improvements for struggling search. Generation of such tasks is inherently difficult, as each task is supposed to trigger struggling and exploring user behavior rather than simple search behavior. Moreover, the everchanging landscape of information needs would render old task sets less ideal if not unusable for system evaluation. In this paper, we propose a task generation method and develop a crowd-powered platform called TaskGenie to generate struggling search tasks online. Our experiments and analysis show that the generated tasks are qualified to emulate struggling search behaviors consisting of ‘repeated similar queries’ and ‘quick-back clicks’, etc. – tasks of diverse topics, high quality and difficulty can be created using this framework. For the benefit of the community, we publicly released the platform, a task set containing 80 topically diverse struggling search tasks generated and examined in this work, and the corresponding anonymized user behavior logs.","SERPs; User behavior; User interaction; Web search","en","conference paper","Springer","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2021-11-08","","","Web Information Systems","","",""
"uuid:0872d069-2401-4686-9155-e6c94a5ecf9b","http://resolver.tudelft.nl/uuid:0872d069-2401-4686-9155-e6c94a5ecf9b","A Highly Linear Wideband Polar Class-E CMOS Digital Doherty Power Amplifier","Hashemi, M. (TU Delft Electronics; ItoM); Zhou, Lei (Ampleon); Shen, Y. (TU Delft Electronics); de Vreede, L.C.N. (TU Delft Electronics)","","2019","This article presents the first application of a digital-intensive intrinsically linear digitally controlled class-E technique in a Doherty configuration. By careful nonlinear segmentation and multiphase RF-clocking along with overdrive-voltage control and automatic duty-cycle correction, it is shown that even the nonlinearities related to Doherty operation can be fully handled by the underlying design such that digital predistorion (DPD) can be, in principle, omitted. The nonlinearity behavior of the whole digital Doherty power amplifier (PA) is analyzed, and closed-form equations are given to predict the AM-AM and AM-phase modulation (PM) curves. In addition, time/phase mismatch between the peak and main branches and the AM and PM signals is accurately compensated. In order to achieve the maximum intrinsic linearity, two separate chips with the same architecture, but different design parameters, are fabricated as the main and peak amplifiers in 40-nm bulk CMOS. To achieve a large RF bandwidth and high passive combiner efficiency, a differential low-loss, wideband Marchand balun-based Doherty power combiner, implemented using reentrant coupled lines with independent second-harmonic control is proposed, and together with the matching network is fabricated on a two-layer PCB. The measured peak/6-dB power backoff P OUT, drain efficiency/power-added efficiency at 2.4 GHz are 17.5 dBm/12.2 dBm, 57%/52% and 36%/25% with VDD main/peak = 0.6 V/0.7 V. Measured results without using DPD show -41-dBc adjacent channel power ratio (ACPR) and -36-dB error vector magnitude (EVM) for a 16-MHz OFDM signal at 2.5 GHz. By using DPD, the measured ACPR and EVM of a 16-MHz/32-MHz OFDM signals are -52 dBc/-48 dBc and -50 dB/-48 dB, respectively.","CMOS; digital power amplifier (DPA); digital predistortion (DPD); Doherty PA; efficient; linear; multiphase RF-clocking; nonlinear sizing; overdrive-voltage control; wideband","en","journal article","","","","","","Accepted author manuscript","","","","","Electronics","","",""
"uuid:badd95ff-737b-4931-ba1a-b22c3da585c4","http://resolver.tudelft.nl/uuid:badd95ff-737b-4931-ba1a-b22c3da585c4","Pulse strategy for suppressing spreading on networks","Liu, Q. (TU Delft Network Architectures and Services); Zhou, Xiaoyu (Student TU Delft); Van Mieghem, P.F.A. (TU Delft Network Architectures and Services)","","2019","In previous modelling efforts to understand the spreading process on networks, each node can infect its neighbors and cure spontaneously, and the curing is traditionally assumed to occur uniformly over time. This traditional curing is not optimal in terms of the trade-off between the effectiveness and cost. A pulse immunization/curing strategy is more efficient and broadly applied to suppress the spreading process. We analyze the pulse curing strategy on networks with the Susceptible-Infected (SI) process. We analytically compute the mean-field epidemic threshold $\tau_c^{p}$ of the pulse SI model and show that $\tau_c^{p}=\frac{1}{\lambda_1}\ln\frac{1}{1-p}$ , where $\lambda_1$ and p are the largest eigenvalue of the adjacency matrix of the contact graph and the fraction of nodes covered by each curing, respectively. These analytical results agree with simulations. Compared to the asynchronous curing process in the extensively studied Markovian SIS process, we show that the pulse curing strategy saves about 36.8%, i.e., $p\approx 0.632$ , of the number of curing operations invariant to the network structure. Our results may help policymakers to design optimal containment strategies and minimize the controlling cost.","","en","journal article","","","","","","Accepted author manuscript","","2020-09-04","","","Network Architectures and Services","","",""
"uuid:9ce8ed16-b4ac-4947-a4c1-511d6065b6bc","http://resolver.tudelft.nl/uuid:9ce8ed16-b4ac-4947-a4c1-511d6065b6bc","Borehole radar response of a mud-invaded oil-bearing layer","Zhou, F. (TU Delft Applied Geophysics and Petrophysics; China University of Geosciences, Wuhan); Hu, Xiangyun (China University of Geosciences, Wuhan); Giannakis, Iraklis (University of West London); Giannopoulos, Antonios (University of Edinburgh); Holliger, Klaus (University of Lausanne; Zhejiang University); Slob, E.C. (TU Delft Applied Geophysics and Petrophysics)","","2019","","","en","poster","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:1df54921-b164-4d4d-a796-cd1c910049ea","http://resolver.tudelft.nl/uuid:1df54921-b164-4d4d-a796-cd1c910049ea","Fully convolutional networks for street furniture identification in panorama images","Ao, Y. (University of Twente); Wang, J. (TU Delft Optical and Laser Remote Sensing); Zhou, M. (Chinese Academy of Sciences); Lindenbergh, R.C. (TU Delft Optical and Laser Remote Sensing); Yang, M. Y. (University of Twente)","","2019","Panoramic images are widely used in many scenes, especially in virtual reality and street view capture. However, they are new for street furniture identification which is usually based on mobile laser scanning point cloud data or conventional 2D images. This study proposes to perform semantic segmentation on panoramic images and transformed images to separate light poles and traffic signs from background implemented by pre-trained Fully Convolutional Networks (FCN). FCN is the most important model for deep learning applied on semantic segmentation for its end to end training process and pixel-wise prediction. In this study, we use FCN-8s model that pre-trained on cityscape dataset and finetune it by our own data. The results show that in both pre-trained model and fine-tuning, transformed images have better prediction results than panoramic images.","Fully Convolutional Networks; Object Identification; Panoramic Images; Semantic Segmentation; Street Furniture","en","journal article","","","","","","","","","","","Optical and Laser Remote Sensing","","",""
"uuid:388be3a7-9c12-444f-bcc4-220bdcce1ad7","http://resolver.tudelft.nl/uuid:388be3a7-9c12-444f-bcc4-220bdcce1ad7","A Morphodynamic Modeling Study on the Formation of the Large‐Scale Radial Sand Ridges in the Southern Yellow Sea","Tao, Jianfeng (Hohai University; Student TU Delft); Wang, Zhengbing (TU Delft Coastal Engineering; Hohai University; Deltares); Zhou, Zeng (Hohai University; The University of Auckland); Xu, Fan (Hohai University; The University of Auckland; East China Normal University); Zhang, Changkuan (Hohai University); Stive, M.J.F. (TU Delft Coastal Engineering)","","2019","The radial sand ridges (denoted as “RSRs” hereafter) in the Southern Yellow Sea, China, are morphologically striking because of the remarkable size and radial planar orientation, standing out as a unique coastal geomorphology among the worldwide sand ridge systems. The formation of this giant fan‐shaped geomorphic feature requires delicate conditions and awaits in‐depth investigation. Using an idealized morphodynamic model, this study unravels the governing factors for the formation of the unique large‐scale RSRs, in comparison with other types of sand ridge systems over the world. The effects of the M2 tidal constituent, the Coriolisforcing, the bed resistance, and the initial water depths on the morphodynamic behavior of the RSRs are explored. Numerical results indicate that the tidal regime, characterized by rotational and progressive current action associated with the tidal bulge, is dependent on the eastern coastline of China as well as latitudinal effects. Through the comparison between the simulated and the measured morphology, this tidal regime is demonstrated to be the key driverin forming and maintaining the present‐day RSRs. The runs with different parameters further suggest that the asymmetric pattern of the RSRs, which shows larger northern sand ridges than the southern ones, results from both the asymmetric distribution of current activity caused by the tidal bulge and unequal sediment supply. Overall, this study highlights the delicate condition, predominantly represented by the particular currents set up by the tidal wave system and the sediment supply, required to shape the striking large‐scale RSRs in the Southern Yellow Sea.","Jiangsu Coast; morphodynamic modeling; radial sand ridges; Southern Yellow Sea; tidal wave systems","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2020-01-05","","","Coastal Engineering","","",""
"uuid:99827774-7669-47aa-8f38-d57156c4dddc","http://resolver.tudelft.nl/uuid:99827774-7669-47aa-8f38-d57156c4dddc","Study of Lateral Flow in a Stratified Tidal Channel-Shoal System: The Importance of Intratidal Salinity Variation","Zhou, Z. (TU Delft Coastal Engineering; East China Normal University); Ge, Jianzhong (East China Normal University; Institute of Eco-Chongming (IEC)); Wang, Zhengbing (TU Delft Coastal Engineering; Deltares); van Maren, D.S. (TU Delft Environmental Fluid Mechanics; Deltares); Ma, Jianfei (East China Normal Univeristy); Ding, Ping Xing (East China Normal Univeristy)","","2019","Lateral flow significantly contributes to the near-bottom mass transport of salinity in a channel-shoal system. In this study, an integrated tripod system was deployed in the transition zone of a channel-shoal system of the Changjiang Estuary (CE), China, to observe the near-bottom physics with high temporal/spatial resolution, particularly focusing on the lateral-flow-induced mass transport. These in situ observations revealed a small-scale salinity fluctuation around low water slack during moderate and spring tidal conditions. A simultaneous strong lateral current was also observed, which was responsible for this small-scale fluctuation. A high-resolution unstructured-grid Finite-Volume Community Ocean Model has been applied for the CE to better understand the mechanism of this lateral flow and its impact on salinity transport. The model results indicate that a significant southward near-bed shoal-to-channel current is generated by the salinity-driven baroclinic pressure gradient. This lateral current affects the salinity transport pattern and the residual current in the cross-channel direction. Cross-channel residual current shows a two-layer structure in the vertical, especially in the intermediate tide when the lateral flow notably occurred. Both observation and model results indicate that near-bottom residual transport of water moved consistently southward (shoal to channel). Mechanisms for this intratidal salinity variation and its implications can be extended to other estuaries with similar channel-shoal features.","channel-shoal system; lateral flow; momentum balance; salinity","en","journal article","","","","","","Accepted Author Manuscript","","2020-02-29","","","Coastal Engineering","","",""
"uuid:f86e4853-bcc2-47b7-8f0a-4259c324cc70","http://resolver.tudelft.nl/uuid:f86e4853-bcc2-47b7-8f0a-4259c324cc70","Associating Borehole Radar Imaging with Petrophysical Properties for a Mud-Contaminated Reservoir","Zhou, F. (TU Delft Applied Geophysics and Petrophysics); Giannakis, Iraklis (University of West London); Giannopoulos, Antonios (University of Edinburgh); Slob, E.C. (TU Delft Applied Geophysics and Petrophysics)","","2019","In the phase of oil drilling, mud filtrate penetrates into porous formations and alters the pore fluid properties. This complicates well logging exploration, and inevitably gives rise to shift in reservoir estimation. Logging engineers deem mud invasion a harm and attempt to eliminate its impact on logging data exploration. However, from our point of view, the mudcontaminated parts of the formation do also carry some valuable information, notably with regard to the key hydraulic properties. Therefore, if adequately characterized, mud invasion effects, in turn, could be utilized for reservoir estimation. Typically, the invasion depth critically depends on the formation porosity and permeability. To achieve this objective, we propose to use borehole radar to determine the mud invasion depth considering a high spatial resolution of ground-penetrating radar (GPR) compared with the conventional logging tools. We implement numerical investigations on the feasibility of this approach by coupling electromagnetic (EM) modelling with fluid flow modelling in an oil-bearing formation disturbed by mud invasion effects. The simulations imply that a time-lapse radar logging is able to extract EM reflection signals from mud invasion front, and the invasion depth and EM velocity can be obtained by a downhole antenna displacement of one source and two receivers. We find that there exists a positive correlation between the estimated invasion depth and permeability curves, and a negative correlation between the estimated velocity and porosity curves. We suggest that borehole radar has potential to estimate permeability and porosity of oil reservoirs, wherein the mud invasion effect is positively utilized. The study demonstrates a potential method of oil reservoir estimation and a novel application of GPR in oil fields","borehole radar; reservoir estimation; mud invasion","en","conference paper","EAGE","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2020-03-12","","","Applied Geophysics and Petrophysics","","",""
"uuid:5c54dc71-42b6-4760-af4b-b2033637c83c","http://resolver.tudelft.nl/uuid:5c54dc71-42b6-4760-af4b-b2033637c83c","How hard is it to detect abrupt changes in the statistics of time series?","van Nooijen, R.R.P. (TU Delft Water Resources); Kolechkina, A.G. (TU Delft Water Resources); Zhou, C. (TU Delft Water Resources)","","2019","","","en","abstract","","","","","","","","","","","Water Resources","","",""
"uuid:976a1b95-219c-47ca-9bfe-4418b65075a7","http://resolver.tudelft.nl/uuid:976a1b95-219c-47ca-9bfe-4418b65075a7","How to predict the location of the defect levels induced by 3d transition metal ions at octahedral sites of aluminate phosphors","Qu, Bingyan (Hefei University of Technology); Zhou, Rulong (Hefei University of Technology); Wang, L. (TU Delft RST/Fundamental Aspects of Materials and Energy; Hefei University of Technology); Dorenbos, P. (TU Delft RST/Luminescence Materials)","","2019","How the 3d transition metal (TM) ions induce defect levels in wide band gap compounds and how these defect levels evolve from compound to compound is very important in understanding and predicting the luminescent properties of TM activated phosphors. This issue is discussed by studying the ground state 3dn level locations of the TM impurity ions (Sc-Zn) incorporated at the octahedral sites of many oxides. These ground state 3dn level locations are obtained by collecting the CT bands from the literature of the past 50 years and also by first-principles calculations. By taking the vacuum level as the reference, we scaled all the locations of the TM ion in 3+ and 2+ states and constructed a zig-zag-curve scheme in α-Al2O3 through connecting the 3dn ground state energies of Sc to Zn. The scheme can be extended to other aluminates easily and so offers a first estimate on where TM levels are located in compounds without complicated theoretical calculations. The estimate can be improved to a higher accuracy if the position of the valence band is known. Our work provides new insights for understanding the luminescent behavior of 3d-TM doped phosphors and may aid in developing 3d ion doped functional materials further.","","en","journal article","","","","","","Accepted Author Manuscript","","2019-11-23","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:ec63ca93-1d57-4af9-8618-259535e5288e","http://resolver.tudelft.nl/uuid:ec63ca93-1d57-4af9-8618-259535e5288e","Measurement-device-independent quantum key distribution coexisting with classical communication","Valivarthi, R. (University of Calgary; ICFO-Institut de Ciencies Fotoniques); Umesh, P. (TU Delft QID/Tittel Lab; University of Calgary); John, C. (University of Calgary); Owen, K. A. (University of Calgary); Verma, V. B. (National Institute of Standards and Technology); Nam, S. W. (National Institute of Standards and Technology); Oblak, D. (University of Calgary); Zhou, Q. (University of Calgary; University of Electronic Science and Technology of China); Tittel, W. (TU Delft QID/Tittel Lab; TU Delft Quantum Communications Lab; TU Delft QuTech Advanced Research Centre; University of Calgary; Kavli institute of nanoscience Delft)","","2019","The possibility for quantum and classical communication to coexist on the same fiber is important for deployment and widespread adoption of quantum key distribution (QKD) and, more generally, a future quantum internet. While coexistence has been demonstrated for different QKD implementations, a comprehensive investigation for measurement-device independent (MDI) QKD - a recently proposed QKD protocol that cannot be broken by quantum hacking that targets vulnerabilities of single-photon detectors - is still missing. Here we experimentally demonstrate that MDI-QKD can operate simultaneously with at least five 10 Gbps bidirectional classical communication channels operating at around 1550 nm wavelength and over 40 km of spooled fiber, and we project communication rates in excess of 10 THz when moving the quantum channel from the third to the second telecommunication window. The similarity of MDI-QKD with quantum repeaters suggests that classical and generalized quantum networks can co-exist on the same fiber infrastructure.","fiber optics; quantum communication; quantum key distribution","en","journal article","","","","","","","","","","","QID/Tittel Lab","","",""
"uuid:5c0cb0cd-e37a-4717-9511-3f468959c80c","http://resolver.tudelft.nl/uuid:5c0cb0cd-e37a-4717-9511-3f468959c80c","An extensive investigation of an eco-approach controller under a partially connected and automated vehicle environment","Jiang, Huifu (Ministry of Transport); Hu, Jia (Tongji University); Park, Byungkyu Brian (University of Virginia); Wang, M. (TU Delft Transport and Planning); Zhou, Wei (Ministry of Transport)","","2019","This study evaluated the performance of an eco-approach control system at signalized intersections under a partially connected and automated vehicle (CAV) environment. This system has the first eco-approach controller able to function with the existence of surrounding human-driven traffic. A previous evaluation only confirmed its benefits. The purpose of this study was to conduct a further extensive test on the controller to identify room for improvement. Two different networks were tested, including an isolated signalized intersection and a corridor with two signalized intersections. The measures of effectiveness (MOEs) adopted were throughput and fuel consumption. All the before-and-after MOEs were compared using t-tests. The results indicate that the controller generally improved the fuel efficiency without harm to the mobility, and its environmental performance was affected by the minimum CAV speed, green ratio, congestion level, and marker penetration rate of CAVs. A detailed investigation revealed that no significant environmental benefit was generated under high congestion levels when the minimum speed of CAVs was more than 20 mph, and the shockwaves caused by the eco-approach control may result in a gating effect that reduces the throughput at the upstream intersection of the corridor under high congestion levels.","Eco-approach; Fuel consumption; Partially connected and automated vehicles environment; Signalized intersections; Throughput","en","journal article","","","","","","","","","","","Transport and Planning","","",""
"uuid:42cf101f-a336-4257-830b-b5b4fd5ad689","http://resolver.tudelft.nl/uuid:42cf101f-a336-4257-830b-b5b4fd5ad689","Data driven discovery of cyber physical systems","Yuan, Ye (Huazhong University of Science and Technology); Tang, Xiuchuan (Huazhong University of Science and Technology); Zhou, Wei (Huazhong University of Science and Technology); Pan, W. (TU Delft Robot Dynamics); Li, Xiuting (Huazhong University of Science and Technology); Zhang, Hai Tao (Huazhong University of Science and Technology); Ding, Han (Huazhong University of Science and Technology); Goncalves, Jorge (Huazhong University of Science and Technology; Cavendish Laboratory; University of Luxembourg)","","2019","Cyber-physical systems embed software into the physical world. They appear in a wide range of applications such as smart grids, robotics, and intelligent manufacturing. Cyber-physical systems have proved resistant to modeling due to their intrinsic complexity arising from the combination of physical and cyber components and the interaction between them. This study proposes a general framework for discovering cyber-physical systems directly from data. The framework involves the identification of physical systems as well as the inference of transition logics. It has been applied successfully to a number of real-world examples. The novel framework seeks to understand the underlying mechanism of cyber-physical systems as well as make predictions concerning their state trajectories based on the discovered models. Such information has been proven essential for the assessment of the performance of cyber-physical systems; it can potentially help debug in the implementation procedure and guide the redesign to achieve the required performance.","","en","journal article","","","","","","","","","","","Robot Dynamics","","",""
"uuid:27a63864-c151-4110-9636-89cc5c3f293d","http://resolver.tudelft.nl/uuid:27a63864-c151-4110-9636-89cc5c3f293d","Filtering the NPP-VIIRS nighttime light data for improved detection of settlements in Africa","Yuan, Xiaotian (Chinese Academy of Sciences; University of Chinese Academy of Sciences); Jia, Li (Chinese Academy of Sciences); Menenti, M. (TU Delft Optical and Laser Remote Sensing; Chinese Academy of Sciences); Zhou, J. (TU Delft Optical and Laser Remote Sensing; Central China Normal University); Chen, Qiting (Chinese Academy of Sciences)","","2019","Observing and understanding changes in Africa is a hotspot in global ecological environmental research since the early 1970s. As possible causes of environmental degradation, frequent droughts and human activities attracted wide attention. Remote sensing of nighttime light provides an effective way to map human activities and assess their intensity. To identify settlements more effectively, this study focused on nighttime light in the northern Equatorial Africa and Sahel settlements to propose a new method, namely, the patches filtering method (PFM) to identify nighttime lights related to settlements from the National Polar-orbiting Partnership Visible Infrared Imaging Radiometer Suite (NPP-VIIRS) monthly nighttime light data by separating signal components induced by biomass burning, thereby generating a new annual image in 2016. The results show that PFM is useful for improving the quality of NPP-VIIRS monthly nighttime light data. Settlement lights were effectively separated from biomass burning lights, in addition to capturing the seasonality of biomass burning. We show that the new 2016 nighttime light image can very effectively identify even small settlements, notwithstanding their fragmentation and unstable power supply. We compared the image with earlier NPP-VIIRS annual nighttime light data from the National Oceanic and Atmospheric Administration (NOAA) National Center for Environmental Information (NCEI) for 2016 and the Sentinel-2 prototype Land Cover 20 m 2016 map of Africa released by the European Space Agency (ESA-S2-AFRICA-LC20). We found that the new annual nighttime light data performed best among the three datasets in capturing settlements, with a high recognition rate of 61.8%, and absolute superiority for settlements of 2.5 square kilometers or less. This shows that the method separates biomass burning signals very effectively, while retaining the relatively stable, although dim, lights of small settlements. The new 2016 annual image demonstrates good performance in identifying human settlements in sparsely populated areas toward a better understanding of human activities.","African settlement; Biomass burning; Human activity; Nighttime light; NPP-VIIRS; Patches filtering method","en","journal article","","","","","","","","","","","Optical and Laser Remote Sensing","","",""
"uuid:5bb290d1-7743-4d6a-827c-71771547c15a","http://resolver.tudelft.nl/uuid:5bb290d1-7743-4d6a-827c-71771547c15a","Modeling high temperature deformation characteristics of AA7020 aluminum alloy using substructure-based constitutive equations and mesh-free approximation method","Eivani, A. R. (Iran University of Science and Technology); Vafaeenezhad, H. (Iran University of Science and Technology); Nikan, O. (Iran University of Science and Technology); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2019","This research was aimed to assess the potential of a radial basis function (RBF) approximation method against the dislocation substructure-based constitutive model in predicting high-temperature deformation behavior of the AA7020 aluminum alloy. Hot compression tests were performed over a range of strain rate of 0.1–100 s−1 and a range of temperature of 350–500 °C up to a strain of 0.6. The hot deformation behavior of the alloy was first described by a substructure kinetic-based constitutive equation, with the effects of strain, strain rate and temperature together with dynamic recovery parameters taken into consideration. A RBF approximation method was then developed to model the flow behavior of the material. The RBF model, as a kind of novel mesh-free function estimation approach, was trained and tested with the obtained datasets from the hot compression tests. The performance of the developed analytical and neural computational models was evaluated using statistical criteria. The results showed that the RBF model was more proficient and accurate in predicting the hot deformation behavior of this aluminum alloy than the substructure-based constitutive model.","Aluminum alloy; Constitutive equation; Hot deformation; Radial Basis Function","en","journal article","","","","","","Accepted Author Manuscript","","2020-11-29","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:f9f6770c-8f34-4184-afa5-0479301a23ef","http://resolver.tudelft.nl/uuid:f9f6770c-8f34-4184-afa5-0479301a23ef","Integrated physical and numerical simulations of weld seam formation during extrusion of magnesium alloy","Bai, Sheng wen (Tsinghua University); Fang, Gang (Tsinghua University); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2019","Solid-state bonding takes place during the extrusion process to produce a hollow metal profile through a porthole die, known as extrusion welding. Defective weld seams degrade extruded products in mechanical properties. The present research was aimed to determine the effect of extrusion condition on the longitudinal weld seam quality of a magnesium alloy, Mg-8Al-0.5Zn-0.5RE, using an integrated physical and numerical simulation method. A special die set-up for physical simulation was designed, through which two magnesium alloy rods were welded in the solid-state under high hydrostatic pressure. Extrusion welding experiments under different conditions were performed. It was demonstrated that, with this die set-up, the formation of weld seams during extrusion to produce hollow profiles could be physically simulated. The extrusion welding experiments were then numerically simulated to reveal strains, stresses and hydrostatic pressures that could not be experimentally measured. Finally, the tensile strength and elongation of the extrusion-welded magnesium alloy were determined and its microstructure was examined. The results showed that the bonding strength increased with decreasing extrusion speed and rising extrusion temperature. For well-bonded rods, weld seam was invisible under optical microscope. Attributed to high temperature and large equivalent strain, complete dynamic recrystallization occurred across the interface, leading to a reduced average grain size and disappearance of weld seam. By applying the integrated physical and numerical simulation method, extrusion process parameters for a particular magnesium alloy can be optimized to ensure weld seam quality of extruded hollow profiles.","Extrusion welding; Magnesium alloy; Microstructure; Solid bonding; Weld seam","en","journal article","","","","","","Accepted Author Manuscript","","2020-10-28","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:985d7914-4b83-4ea3-8d83-8feb24b57ae2","http://resolver.tudelft.nl/uuid:985d7914-4b83-4ea3-8d83-8feb24b57ae2","Automatic shadow detection in urban very-high-resolution images using existing 3D models for free training","Zhou, K. (TU Delft Optical and Laser Remote Sensing); Lindenbergh, R.C. (TU Delft Optical and Laser Remote Sensing); Gorte, Ben (University of New South Wales)","","2019","Up-to-date 3D city models are needed for many applications. Very-high-resolution (VHR) images with rich geometric and spectral information and a high update rate are increasingly applied for the purpose of updating 3D models. Shadow detection is the primary step for image interpretation, as shadow causes radiometric distortions. In addition, shadow itself is valuable geometric information. However, shadows are often complicated and environment-dependent. Supervised learning is considered to perform well in detecting shadows when training samples selected from these images are available. Unfortunately, manual labeling of images is expensive. Existing 3D models have been used to reconstruct shadows to provide free, computer-generated training samples, i.e., samples free from intensive manual labeling. However, accurate shadow reconstruction for large 3D models consisting of millions of triangles is either difficult or time-consuming. In addition, due to inaccuracy and incompleteness of the model, and different acquisition time between 3D models and images, mislabeling refers to training samples that are shadows but labeled as non-shadows and vice versa. We propose a ray-tracing approach with an effective KD tree construction to feasibly reconstruct accurate shadows for a large 3D model. An adaptive erosion approach is first provided to remove mislabeling effects near shadow boundaries. Next, a comparative study considering four classification methods, quadratic discriminant analysis (QDA) fusion, support vector machine (SVM), K nearest neighbors (KNN) and Random forest (RF), is performed to select the best classification method with respect to capturing the complicated properties of shadows and robustness to mislabeling. The experiments are performed on Dutch Amersfoort data with around 20% mislabels and the Toronto benchmark by simulating mislabels from inverting shadows to non-shadows. RF is tested to give robust and best results with 95.38% overall accuracy (OA) and a value of 0.9 for kappa coefficient (KC) for Amersfoort and around 96% OA and 0.92 KC for Toronto benchmarks when no more than 50% of shadows are inverted. QDA fusion and KNN are tested to be robust to mislabels but their capability to capture complicated properties of shadows is worse than RF. SVM is tested to have a good capability to separate shadow and non-shadows but is largely affected by mislabeled samples. It is shown that RF with free-training samples from existing 3D models is an automatic, effective, and robust approach for shadow detection from VHR images.","3D city model; Erosion; Free training; KD tree; Mislabels; Random forest; Ray tracing; Robust; Shadow detection","en","journal article","","","","","","","","","","","Optical and Laser Remote Sensing","","",""
"uuid:249761e4-27f3-4045-9afb-3db2a5d975b2","http://resolver.tudelft.nl/uuid:249761e4-27f3-4045-9afb-3db2a5d975b2","Ship classification based on ship behavior clustering from AIS data","Zhou, Y. (TU Delft Rivers, Ports, Waterways and Dredging Engineering); Daamen, W. (TU Delft Transport and Planning); Vellinga, T. (TU Delft Rivers, Ports, Waterways and Dredging Engineering); Hoogendoorn, S.P. (TU Delft Transport and Planning)","","2019","Since the introduction of the Automatic Identification System (AIS), AIS data has proven to be a valuable source of ship behavior analysis using data mining. It records ship position, speed and other behavior attributes at specific time intervals in all voyages at sea and in ports. However, the current studies in ship behavior analyze the behavior patterns either with a subjective choice of classification for behavior differences among the groups of ships or without any classification at all. In order to fill this gap, a new methodology for ship classification in ports based on behavior clustering is developed by analyzing AIS data from the port of Rotterdam. Besides a proper data preparation, the proposed methodology consists of two steps: step I, clustering ship behavior in a port area and identifying the characteristics of the clusters; step II, classifying ships to such behavior clusters based on the ship characteristics. The clustering results present both the behavior patterns and the behavior change patterns for ship path and speed over ground, which are the dominant behavior attributes for ships in ports. Some patterns of integral ship behavior can also be revealed by investigating the correlation between the two behavior attributes. Our research has shown that length and beam can be adopted as explanatory variable to classify ships to the corresponding behavior clusters. The classifiers are developed based on both unsupervised discretization (equal width binning) and supervised discretization (Chi2). The performances of classifiers are compared by three evaluation metrics, including Average Accuracy, F 1 score, and AUC. We found that the classification based on multi-criteria is more accurate than using a single criterion. The classifications based on Chi2 discretization outperform the ones with equal width discretization. The outcome leads to a systematic understanding of ship behavior in a port area and can be used to predict the ship behavior pattern based on their characteristics and simulate the ship behavior.","AIS data; Behavior clustering; Data mining; Ports and waterways; Ship classification","en","journal article","","","","","","Accepted Author Manuscript","","2021-02-15","","Transport and Planning","Rivers, Ports, Waterways and Dredging Engineering","","",""
"uuid:97bf6b5c-caf9-4864-9053-15c4e2a694e8","http://resolver.tudelft.nl/uuid:97bf6b5c-caf9-4864-9053-15c4e2a694e8","Impacts of 5d electron binding energy and electron-phonon coupling on luminescence of Ce 3+ in Li 6 Y(BO 3 ) 3","Ou, Yiyi (Sun Yat-sen University); Zhou, Weijie (Sun Yat-sen University); Hou, Dejian (Hanshan Normal University, Chaozhou); Brik, Mikhail G. (Chongqing University of Posts and Telecommunications; University of Tartu; Jan Długosz University); Dorenbos, P. (TU Delft RST/Luminescence Materials); Huang, Yan (Institute of High Energy Physics Chinese Academy of Science); Liang, Hongbin (Sun Yat-sen University)","","2019","In this work, the crystal structure and electronic structure as well as the synchrotron radiation vacuum ultraviolet-ultraviolet-visible (VUV-UV-vis) luminescence properties of Li 6 Y(BO 3 ) 3 (LYBO):Ce 3+ phosphors were investigated in detail. The Rietveld refinement and DFT calculation reveal the P2 1 /c monoclinic crystal phase and the direct band gap of the LYBO compound, respectively. Only one kind of Ce 3+ 4f-5d transition is resolved in terms of the low temperature VUV-UV excitation, UV-vis emission spectra and luminescence decay curves. Furthermore, by constructing the vacuum referred binding energy (VRBE) scheme and applying the frequency-degenerate vibrational model, the impacts of 5d electron binding energy and electron-phonon coupling on luminescence of Ce 3+ in LYBO are analysed. The results show that the Ce 3+ emission in LYBO possesses a moderate intrinsic thermal stability. With the increase in concentration, the thermal stability of the emission gets worse due to the possible thermally-activated concentration quenching. In addition, the simulation of Ce 3+ emission profile at low temperature reveals that the 4f-5d electronic transitions of Ce 3+ ions can be treated to couple with one frequency-degenerate vibrational mode having the effective phonon energy of ∼257 cm −1 with the corresponding Huang-Rhys parameter of ∼6, which indicates a strong electron-phonon interaction of Ce 3+ luminescence in the Li 6 Y(BO 3 ) 3 host. Finally, the X-ray excited luminescence spectrum of the LYBO:5%Ce 3+ phosphor is measured to check the potential scintillator applications.","","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:20df38e2-9534-4b25-90b4-315ab1a8197d","http://resolver.tudelft.nl/uuid:20df38e2-9534-4b25-90b4-315ab1a8197d","Applying aluminum-organic matter precipitates to reduce soil permeability in-situ: A field and modeling study","Zhou, Jianchao (TU Delft Geo-engineering); Laumann, S.J. (TU Delft Geo-engineering; Tauw); Heimovaara, T.J. (TU Delft Geoscience and Engineering)","","2019","Using naturally occurring processes to modify the engineering properties of the subsurface has received increasing attention from industry and research communities as they aid in the development of cost-effective, robust and sustainable engineering technologies. In line with this trend, we propose to use precipitates of aluminum (Al) and organic matter (OM) to reduce soil permeability in-situ. This process is inspired by podzolization: a soil stratification process where a layer with low permeability is developed at depth via the precipitation of metal-OM complexes. In this study, the concept of applying Al-OM precipitates for in-situ soil permeability reduction was for the first time applied in the field. The aim of the field experiment was to create a cylindrical flow barrier in a sand layer at depth. In order to design and engineer the field application, we performed a series of scenario analyses with a site-specific 3D reactive transport model. This led to an in-situ engineering approach where a flow barrier was created by separate injection of Al and OM using a combined injection/extraction strategy. During the field application, the local variation of soil conditions required significant modifications to the design. Further scenario analyses with the model were conducted to adapt the original design and to understand the consequences of these modifications. The results show that a cylindrical flow barrier was created after an injection period of 8 days. The precipitation of Al-OM is a highly localized process, where large amount of precipitates is formed in the close vicinity of the injection filter screens. Evaluation of pumping tests that were performed after the injection activities revealed that the permeability of the treated sand was reduced to 2% of its original value. This first full-scale field test demonstrates that applying Al-OM precipitates is a suitable bio-based engineering tool to reduce soil permeability in-situ.","Bio-based engineering; Flow barrier; In-situ permeability reduction; Metal-organic matter complexation; Reactive transport modeling","en","journal article","","","","","","","","","","Geoscience and Engineering","Geo-engineering","","",""
"uuid:b682ca8e-4367-439a-a637-233754c4c94f","http://resolver.tudelft.nl/uuid:b682ca8e-4367-439a-a637-233754c4c94f","Investigation into the extrudability of a new Mg-Al-Zn-RE alloy with large amounts of alloying elements","Bai, Sheng Wen (Tsinghua University); Fang, Gang (Tsinghua University); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2019","The present study was aimed at determining the extrudability of a newly developed Mg-Al-Zn-RE magnesium alloy with large amounts of alloying elements. The experimental and numerical investigation clearly showed that the extrudate temperature was a crucial factor in deciding if a critical temperature between 754 K and 768 K (481 °C and 495 °C) was reached during extrusion, above which hot shortness occurred. Under the extrusion conditions applied, dynamic recrystallization (DRX) occurred, leading to grain refinement from a mean grain size of 165 μm in the as-solid-solution-treated billet to 8.0 to 10.9 μm in the extruded rods. Second-phase particles, such as Mg17Al12 and Al11La3, were found to distribute on grain boundaries and aid in grain refinement. The mechanical properties of the extrudate were greatly influenced by the as-extruded microstructure and extrusion condition. As the initial billet temperature decreased, the ultimate tensile strength (UTS) and elongation of the alloy increased, while yield strength (YS) remained almost unchanged. At an initial billet temperature of 523 K (250 °C), a stem speed of 3.93 mm/s, and a reduction ratio of 29.8, the extruded magnesium alloy had a mean grain size of 8 μm. Its YS, UTS, and elongation reached 217 ± 3 MPa, 397 ± 7 MPa, and 20 ± 1.3 pct, respectively.","","en","journal article","","","","","","Accepted Author Manuscript","","2020-05-17","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:1e17d267-5896-4c62-bb11-da2b80c97978","http://resolver.tudelft.nl/uuid:1e17d267-5896-4c62-bb11-da2b80c97978","Corrosion fatigue behavior of additively manufactured biodegradable porous iron","Li, Y. (TU Delft Biomaterials & Tissue Biomechanics); Lietaert, K. (Katholieke Universiteit Leuven; 3D Systems – LayerWise NV); Li, W. (TU Delft (OLD) MSE-3); Zhang, X.Y. (Tsinghua University); Leeflang, M.A. (TU Delft Biomaterials & Tissue Biomechanics); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2019","The corrosion fatigue behavior of additively manufactured topologically ordered porous iron based on diamond unit cells was studied for the first time to understand its response to cyclic loading in a simulated physiological environment. The material exhibited high fatigue resistance with fatigue strengths being 70% and 65% of yield stress in air and revised simulated body fluid, respectively, mainly due to its slow degradation and excellent ductility. However, cyclic loading significantly increased biodegradation rate, especially at higher stress levels. The observed extraordinary fatigue strength, slow biodegradation and high ductility underline the importance of porous iron as a promising bone-substituting material.","Additive manufacturing; Biodegradation; Corrosion fatigue; Iron scaffold; Selective laser melting","en","journal article","","","","","","Accepted Author Manuscript","","2021-06-05","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:87c26d9e-7707-4acc-8639-954067637e00","http://resolver.tudelft.nl/uuid:87c26d9e-7707-4acc-8639-954067637e00","Comparative evaluation of the sludge characteristics along the height of upflow anaerobic sludge blanket coupled ultrafiltration systems","Ozgun, H. (TU Delft Sanitary Engineering; Istanbul Technical University); Ersahin, M.E. (TU Delft Sanitary Engineering; Istanbul Technical University); Zhou, Z. (TU Delft Sanitary Engineering; Sun Yat-sen University); Tao, Y. (TU Delft Sanitary Engineering; Harbin Institute of Technology); Spanjers, H. (TU Delft Sanitary Engineering); van Lier, J.B. (TU Delft Sanitary Engineering)","","2019","This study provides a comparison of the sludge characteristics along the height of an upflow anaerobic sludge blanket (UASB) reactor in terms of sludge morphology, activity and stability. The main aim of this study was to identify the best location (i.e. where sludge is of lowest stability and/or highest concentration) in the sludge bed for conveying the sludge from the low temperature UASB reactor to a digester. The sludge profile was investigated by collecting sludge samples along the different heights of the UASB-anaerobic membrane bioreactor treating municipal wastewater. Results showed that total solids and volatile solids concentrations decreased with height, and the highest chemical oxygen demand concentration was observed at the bottom of the reactor. Active biomass remained near inlet of the reactor; whereas, non-active biomass consisted of loose, suspended particles and flocculents moved towards the top. This was confirmed by the high specific COD consumption rate near the inlet and poor specific COD biodegradation in the remaining portions of the bioreactor. Apparently, the assumption of a completely mixed sludge bed behavior for the UASB reactor, being part of an AnMBR system, does not hold for this type of reactor systems even at low temperatures, which makes the location in sludge bed from where the sludge is to be conveyed to the digester of operational importance. Considering the observed sludge bed stratification, the sludge to be recirculated from the UASB reactor to the digester is recommended to be taken from 40 to 50% of the sludge bed height.","Anaerobic membrane bioreactor; Microbial community; Municipal wastewater; Sludge stability; Ultrafiltration; Upflow anaerobic sludge blanket reactor","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2019-10-24","","","Sanitary Engineering","","",""
"uuid:6c30c457-8e86-454a-89b3-113b12a07967","http://resolver.tudelft.nl/uuid:6c30c457-8e86-454a-89b3-113b12a07967","Review of maritime traffic models from vessel behavior modeling perspective","Zhou, Y. (TU Delft Rivers, Ports, Waterways and Dredging Engineering); Daamen, W. (TU Delft Transport and Planning); Vellinga, T. (TU Delft Rivers, Ports, Waterways and Dredging Engineering); Hoogendoorn, S.P. (TU Delft Transport and Planning)","","2019","The importance of maritime transport keeps increasing with the trade globalization. With the growing demand for waterborne transport, vessel traffic flows are also expected to increase. This paper reviews maritime traffic models from the vessel behavior modeling perspective. The maritime traffic models include the models for vessel traffic both at sea and in confined water area. The aim of this paper is to analyze the underlying modeling paradigms and to assess the extent in which maritime traffic models can represent vessel behavior. Focusing on vessel behavior modeling, this paper provides a broad overview of the current literature on maritime traffic models of the last decades. The commercial models are not included due to the limit of information. To compare the capabilities of models in capturing the vessel behavior characteristics, the considered models are assessed from different aspects of vessel behavior representation, external impact modeling, and model applicability. The assessment shows that none of the existing models describe all dynamic kinetic information in detail for different vessels and consider the impacts from a full range of external factors, which is possibly due to the specific purpose when the models were developed. The models developed for specific vessels in specific situations ignore the irrespective behavioral details in other possible scenarios. Models without proper calibration and validation limit the applicability in other cases. It also indicates that few models can accurately simulate the different vessel behavior at a microscopic level. To investigate the possible potential and limitations, the models have been assessed and discussed to indicate the underlying modeling paradigms based on the modeling characteristics. Future developments can focus on the behavior of different vessels in different types of water areas and the corresponding impacts from external conditions (e.g. visibility, wind, current), vessel encounters and traffic rules. Through calibration and validation, future models should be able to fit the vessel behavior in real-life situations.","Assessment; Comparison; Individual behavioral law; Maritime traffic; Simulation model; Vessel behavior","en","review","","","","","","Accepted Author Manuscript","","2021-06-11","","Transport and Planning","Rivers, Ports, Waterways and Dredging Engineering","","",""
"uuid:06e843bd-9102-4400-ac91-88011e6531dc","http://resolver.tudelft.nl/uuid:06e843bd-9102-4400-ac91-88011e6531dc","Building segmentation from airborne vhr images using mask r-cnn","Zhou, K. (TU Delft Optical and Laser Remote Sensing); Chen, Y. (Student TU Delft); Smal, I.V. (TU Delft Optical and Laser Remote Sensing); Lindenbergh, R.C. (TU Delft Optical and Laser Remote Sensing)","","2019","Up-to-date 3D building models are important for many applications. Airborne very high resolution (VHR) images often acquired annually give an opportunity to create an up-to-date 3D model. Building segmentation is often the first and utmost step. Convolutional neural networks (CNNs) draw lots of attention in interpreting VHR images as they can learn very effective features for very complex scenes. This paper employs Mask R-CNN to address two problems in building segmentation: detecting different scales of building and segmenting buildings to have accurately segmented edges. Mask R-CNN starts from feature pyramid network (FPN) to create different scales of semantically rich features. FPN is integrated with region proposal network (RPN) to generate objects with various scales with the corresponding optimal scale of features. The features with high and low levels of information are further used for better object classification of small objects and for mask prediction of edges. The method is tested on ISPRS benchmark dataset by comparing results with the fully convolutional networks (FCN), which merge high and low level features by a skip-layer to create a single feature for semantic segmentation. The results show that Mask R-CNN outperforms FCN with around 15% in detecting objects, especially in detecting small objects. Moreover, Mask R-CNN has much better results in edge region than FCN. The results also show that choosing the range of anchor scales in Mask R-CNN is a critical factor in segmenting different scale of objects. This paper provides an insight into how a good anchor scale for different dataset should be chosen.","3D building model; building segmentation; different scale of building; edge; FCN; FPN; Mask R-CNN; RPN; VHR image","en","journal article","","","","","","","","","","","Optical and Laser Remote Sensing","","",""
"uuid:d1ef55f7-0190-4082-9603-08bec81d6850","http://resolver.tudelft.nl/uuid:d1ef55f7-0190-4082-9603-08bec81d6850","Relaxing the control-gain assumptions of DSC design for nonlinear MIMO systems","Chen, Yong (Air Force Engineering University); Lv, Maolong (TU Delft Team Bart De Schutter); Baldi, S. (TU Delft Team Bart De Schutter; Southeast University); Liu, Zongcheng (Air Force Engineering University); Zhang, Wenqian (Air Force Engineering University); Zhou, Yang (Air Force Engineering University)","","2019","This work focuses on adaptive neural dynamic surface control (DSC) for an extended class of nonlinear MIMO strict-feedback systems whose control gain functions are continuous and possibly unbounded. The method is based on introducing a compact set which is eventually proved to be an invariant set: thanks to this set, the restrictive assumption that the upper and lower bounds of control gain functions must be bounded is removed. This method substantially enlarges the class of systems for which DSC can be applied. By utilizing Lyapunov theorem and invariant set theory, it is rigorously proved that all signals in the closed-loop systems are semi-globally uniformly ultimately bounded (SGUUB) and the output tracking errors converge to an arbitrarily small residual set. A simulation example is provided to demonstrate the effectiveness of the proposed approach.","Adaptive systems; MIMO communication; Stability analysis; Nonlinear systems; Backstepping; Control design","en","conference paper","IEEE","","","","","Accepted Author Manuscript","","","","","Team Bart De Schutter","","",""
"uuid:9be9c07f-0399-49f7-b6bf-99d725ad7e25","http://resolver.tudelft.nl/uuid:9be9c07f-0399-49f7-b6bf-99d725ad7e25","Comparative analysis of nonparametric change-point detectors commonly used in hydrology","Zhou, C. (TU Delft Water Resources); van Nooijen, R.R.P. (TU Delft Water Resources); Kolechkina, A.G. (TU Delft Water Resources); Hrachowitz, M. (TU Delft Water Resources)","","2019","Several commonly-used nonparametric change-point detection methods are analysed in terms of power, ability and accuracy of the estimated change-point location. The analysis is performed with synthetic data for different sample sizes, two types of change and different magnitudes of change. The methods studied are the Pettitt method, a method based on the Cramér von Mises (CvM) two-sample test statistic and a variant of the CUSUM method. The methods differ considerably in behaviour. For all methods the spread of estimated change-point location increases significantly for points near one of the ends of the sample. Series of annual maximum runoff for four stations on the Yangtze River in China are used to examine the performance of the methods on real data. It was found that the CvM-based test gave the best results, but all three methods suffer from bias and low detection rates for change points near the ends of the series.","ability; change-point detection; Cramér von Mises test; CUSUM test; Pettitt test; power; uncertainty","en","journal article","","","","","","","","","","","Water Resources","","",""
"uuid:5685c1c7-a2f9-4f2e-8525-9578a1773d7d","http://resolver.tudelft.nl/uuid:5685c1c7-a2f9-4f2e-8525-9578a1773d7d","Determining finite-width-correction factors for fatigue crack growth prediction in GLARE using the equivalent compliance method","Zhao, Yuan (Harbin Institute of Technology); Alderliesten, R.C. (TU Delft Structural Integrity & Composites); Wu, Zengwen (Harbin Institute of Technology); Zhou, Zhengong (Harbin Institute of Technology); Fang, Guodong (Harbin Institute of Technology); Zhang, Jiazhen (Harbin Institute of Technology); Benedictus, R. (TU Delft Structural Integrity & Composites)","","2019","Finite-width-correction factors (FWCF) are required for GLARE to accurately predict fatigue crack growth using linear elastic fracture mechanics. As demonstrated in earlier work, these factors effectively correct for the change in specimen compliance, which in GLARE relates to intact fibre layers and the formation of delaminations between these layers and the cracked metal layers. Therefore, the development of delaminations in various GLARE grades were studied using digital image correlation during fatigue crack growth experiments under different maximum stresses and stress ratios. The elongation of GLARE in loading direction was recorded by crosshead displacement during fatigue testing, and was correlated to the observed development of the delamination area. The relationship between effective delamination area and effective GLARE specimen compliance is used as basis for determining explicit formulations for the FWCF for GLARE.","Applied work; Compliance; Delamination; Finite-width-correction factor; GLARE","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2019-06-01","","","Structural Integrity & Composites","","",""
"uuid:f1fba7c4-0342-4daa-b835-16197761c259","http://resolver.tudelft.nl/uuid:f1fba7c4-0342-4daa-b835-16197761c259","On the physics of applying finite width and geometry correction factors in fatigue crack growth predictions of GLARE","Zhao, Y. (TU Delft Structural Integrity & Composites; Harbin Institute of Technology); Alderliesten, R.C. (TU Delft Structural Integrity & Composites); Zhou, Zhengong (Harbin Institute of Technology); Fang, Guodong (Harbin Institute of Technology); Zhang, Jiazhen (Harbin Institute of Technology); Benedictus, R. (TU Delft Aerospace Structures & Materials; TU Delft Structural Integrity & Composites)","","2018","In general, a finite width correction to stress intensity factor (SIF) is required in the fatigue crack growth. The finite width correction factor can be explained physically from the energy point of view. It is assumed that the finite width correction factor primarily constitutes an energy correction factor, i.e. it corrects the applied load for the work applied. To evaluate the finite width correction for FMLs, constant amplitude load fatigue crack growth tests were performed on monolithic aluminium 2024-T3 and the Fibre Metal Laminate GLARE containing 2024-T3 aluminium layers. The loads and displacements were recorded to quantify the total amount of work applied throughout each fatigue test. The crack length and delamination size were monitored by using digital image correlation technique to evaluate the dissipative energy. It appears that the Feddersen's and all other standard finite width correction significantly overestimates the effect for FMLs. The finite width correction to SIF for FMLs is small but cannot be neglected, and it is also greatly related to the Glare grades, stress ratio and stress level.","Energy; Fatigue; Fibre metal laminates; Finite width correction; Stress intensity factor","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2019-03-01","","Aerospace Structures & Materials","Structural Integrity & Composites","","",""
"uuid:5800f78a-6f6a-4824-9e0f-ce3b99f78116","http://resolver.tudelft.nl/uuid:5800f78a-6f6a-4824-9e0f-ce3b99f78116","A computationally cheap trick to determine shadow in a voxel model","Gorte, B. G.H. (University of New South Wales); Zhou, K. (TU Delft Optical and Laser Remote Sensing); Van Der Sande, C. J. (NEO BV.); Valk, C. (NEO BV.)","","2018","Representation of scenes on the Earth surface by using voxels is gaining attention because of its suitability for integrating heterogeneous data sources in simulations and quantitative models. Computation of shadows in such models is needed, for example, to obtain crop suitability of agricultural fields in the presence of trees and buildings, or to analyze urban heat island causes and effects. We present an efficient algorithm to compute which of the voxels in a dataset receive direct sunlight, given the solar azimuth and elevation angles. The algorithm can work with multiple (sparse and dense) voxel storage strategies.","3D City models; Quantitative Modelling; Shadow; Simulation; Voxels","en","journal article","","","","","","","","","","","Optical and Laser Remote Sensing","","",""
"uuid:e3d4a8c4-82f1-4ec3-abef-f4231597e1c8","http://resolver.tudelft.nl/uuid:e3d4a8c4-82f1-4ec3-abef-f4231597e1c8","Quantum technologies with optically interfaced solid-state spins","Awschalom, David D. (University of Chicago; Argonne National Laboratory); Hanson, R. (TU Delft QID/Hanson Lab; TU Delft QN/Hanson Lab); Wrachtrup, Jörg (University of Stuttgart; Max Planck Institute for Solid State Research); Zhou, Brian B. (University of Chicago; Boston College)","","2018","Spins of impurities in solids provide a unique architecture to realize quantum technologies. A quantum register of electron and nearby nuclear spins in the lattice encompasses high-fidelity state manipulation and readout, long-lived quantum memory, and long-distance transmission of quantum states by optical transitions that coherently connect spins and photons. These features, combined with solid-state device engineering, establish impurity spins as promising resources for quantum networks, information processing and sensing. Focusing on optical methods for the access and connectivity of single spins, we review recent progress in impurity systems such as colour centres in diamond and silicon carbide, rare-earth ions in solids and donors in silicon. We project a possible path to chip-scale quantum technologies through sustained advances in nanofabrication, quantum control and materials engineering.","","en","review","","","","","","Accepted Author Manuscript","","2019-02-28","","","QID/Hanson Lab","","",""
"uuid:44a3f674-f8e0-4414-a92e-fe1dd7139f96","http://resolver.tudelft.nl/uuid:44a3f674-f8e0-4414-a92e-fe1dd7139f96","Denoising controlled-source electromagnetic data using least-squares inversion","Yang, Yang (Central South University China; Shandong University); Li, Diquan (Central South University China); Tong, Tiegang (Central South University China); Zhang, D. (TU Delft ImPhys/Acoustical Wavefield Imaging); Zhou, Yatong (Hebei University of Technology); Chen, Yangkang (Zhejiang University)","","2018","Strong noise is one of the toughest problems in the controlled-source electromagnetic (CSEM) method, which highly affects the quality of recorded data. The three main types of noise existing in CSEM data are periodic noise, Gaussian white noise, and nonperiodic noise, among which the nonperiodic noise is thought to be the most difficult to remove. We have developed a novel and effective method for removing such nonperiodic noise by formulating an inverse problem that is based on inverse discrete Fourier transform and several time windows in which only Gaussian white noise exists. These critical locations, which we call reconstruction locations, can be found by taking advantage of the continuous wavelet transform (CWT) and the temporal derivative of the scalogram generated by CWT. The coefficients of the nonperiodic noise are first estimated using the new least-squares method, and then they are subtracted from the coefficients of the raw data to produce denoised data. Together with the nonperiodic noise, we also remove Gaussian noise using the proposed method. We validate the methodology using real-world CSEM data.","Electromagnetics; Least-squares; Noise; Signal processing; Wavelet","en","journal article","","","","","","","","","","","ImPhys/Acoustical Wavefield Imaging","","",""
"uuid:296bedba-deb3-4109-a9ef-0e8de8b86a21","http://resolver.tudelft.nl/uuid:296bedba-deb3-4109-a9ef-0e8de8b86a21","3D building change detection between current vhr images and past LiDAR data","Zhou, K. (TU Delft Optical and Laser Remote Sensing); Gorte, B. (University of New South Wales); Lindenbergh, R.C. (TU Delft Optical and Laser Remote Sensing); Widyaningrum, E. (TU Delft Optical and Laser Remote Sensing)","","2018","Change detection is an essential step to locate the area where an old model should be updated. With high density and accuracy, LiDAR data is often used to create a 3D city model. However, updating LiDAR data at state or nation level often takes years. Very high resolution (VHR) images with high updating rate is therefore an option for change detection. This paper provides a novel and efficient approach to derive pixel-based building change detection between past LiDAR and new VHR images. The proposed approach aims notably at reducing false alarms of changes near edges. For this purpose, LiDAR data is used to supervise the process of finding stereo pairs and derive the changes directly. This paper proposes to derive three possible heights (so three DSMs) by exploiting planar segments from LiDAR data. Near edges, the up to three possible heights are transformed into discrete disparities. A optimal disparity is selected from a reasonable and computational efficient range centered on them. If the optimal disparity is selected, but still the stereo pair found is wrong, a change has been found. A Markov random field (MRF) with built-in edge awareness from images is designed to find optimal disparity. By segmenting the pixels into plane and edge segments, the global optimization problem is split into many local ones which makes the optimization very efficient. Using an optimization and a consecutive occlusion consistency check, the changes are derived from stereo pairs having high color difference. The algorithm is tested to find changes in an urban areas in the city of Amersfoort, the Netherlands. The two different test cases show that the algorithm is indeed efficient. The optimized disparity images have sharp edges along those of images and false alarms of changes near or on edges and occlusions are largely reduced.","Change detection; Disparity; DSM quality; LiDAR data; MRF; Optimization; VHR images","en","journal article","","","","","","","","","","","Optical and Laser Remote Sensing","","",""
"uuid:65af6d89-c3bc-45cd-8f99-849bc093ae0a","http://resolver.tudelft.nl/uuid:65af6d89-c3bc-45cd-8f99-849bc093ae0a","Extraction of building roof edges from LiDAR data to optimize the digital surface model for true orthophoto generation","Widyaningrum, E. (TU Delft Optical and Laser Remote Sensing; Geospatial Information Agency); Lindenbergh, R.C. (TU Delft Optical and Laser Remote Sensing); Gorte, B.G.H. (University of New South Wales); Zhou, K. (TU Delft Optical and Laser Remote Sensing)","","2018","Various kinds of urban applications require true orthophotos. True orthophoto generation requires a DSM (Digital Surface Model) to project the photo orthogonally and minimize geometric distortion due to topographic variance. DSMs are often generated from airborne laser scan data. In urban scenes, DSM data may fail to deliver sharp and straight building roof edges. This will affect the quality of the resulting orthophotos. Therefore, it is necessary to incorporate good quality building outlines as breaklines during DSM interpolation. This study proposes a data-driven approach to construct building roof outlines from LiDAR point clouds by a workflow consisting of the following steps: given roof segments, roof boundary points are extracted using a concave hull algorithm. Straight edges may be difficult to find in complex roof configurations. Therefore, two ingredients are combined. First, RanSAC corner point preselection, and second, DBSCAN-based clustering of edge points. The method is demonstrated on an area of ±1.2 km2 containing 42 buildings of different characteristics. A quality assessment shows that the proposed method is able to deliver 92% of building lines with acceptable geometric accuracy in comparison to a building line in the base map.","Aerial photos; DSM; Edge detection; LiDAR; True orthophoto","en","journal article","","","","","","","","","","","Optical and Laser Remote Sensing","","",""
"uuid:26d5bad5-712d-47b2-8df9-d57e1f14599e","http://resolver.tudelft.nl/uuid:26d5bad5-712d-47b2-8df9-d57e1f14599e","Deterioration and optimal rehabilitation modelling for urban water distribution systems","Zhou, Y. (TU Delft Sanitary Engineering)","Vairavamoorthy, K. (promotor); Delft University of Technology (degree granting institution)","2018","Pipe failures in water distribution systems can have a serious impact and hence it’s important to maintain the condition and integrity of the distribution system. This book presents a whole-life cost optimisation model for the rehabilitation of water distribution systems. It combines a pipe breakage number prediction model with a pipe criticality assessment model, which enables the creation of a well-constructed and more tightly constrained optimisation model. The pipe breakage number prediction model combines information on the physical characteristics of the pipes with historical information on breakage and failure rates. A weighted multiple nonlinear regression analysis is applied to describe the condition of different pipe groups. The criticality assessment model combines a pipe’s condition with its hydraulic significance through a modified TOPSIS. This model enables the optimisation to focus its efforts on those important pipes. The whole life cost optimal rehabilitation model is a multiple-objective and multiple-stage model, which provides a suite of rehabilitation decisions that minimise the whole life cost while maximising its long-term performance. The optimisation model is solved using a modified NSGA-II. The utility of the developed models is that it allows decision makers to prioritize their rehabilitation strategy in a proactive and cost-effective manner.","","en","doctoral thesis","CRC Press / Balkema - Taylor & Francis Group","978-1-138-32281-3","","","","","","","","","Sanitary Engineering","","",""
"uuid:5b875915-2518-4ec8-a1a0-07ad057edab4","http://resolver.tudelft.nl/uuid:5b875915-2518-4ec8-a1a0-07ad057edab4","Online reinforcement learning control for aerospace systems","Zhou, Y. (TU Delft Control & Simulation)","Mulder, Max (promotor); Chu, Q. P. (promotor); Delft University of Technology (degree granting institution)","2018","Reinforcement Learning (RL) methods are relatively new in the field of aerospace guidance, navigation, and control. This dissertation aims to exploit RL methods to improve the autonomy and online learning of aerospace systems with respect to the a priori unknown system and environment, dynamical uncertainties, and partial observability. In the first part of this dissertation, incremental Approximate Dynamic Programming (iADP) methods are proposed. Instead of using nonlinear function approximators to approximate the true cost-to-go, iADP methods use an (extended) incremental model to deal with the nonlinearity of unknown systems and uncertainties of the environment. In the second part, online Adaptive Critic Designs (ACDs) are proposed based on the incremental model. This method replaces the global system model approximator with an incremental model. This approach, therefore, does not need off-line training stages and may accelerate online learning. In the third part, the hybrid Hierarchical Reinforcement Learning (hHRL) method is proposed for guidance and navigation problems. This method consists of several hierarchical levels, where each level uses different methods to optimize the learning with different types of information and objectives. In conclusion, this dissertation contributes with several methods that improve the intelligence and autonomy of aerospace systems. These improvements are mainly from three perspectives: 1) enhancing the adaptability and efficiency of low-level control, 2) improving the intelligence and online learning ability of guidance, navigation, and control, and 3) creating a well-organized hierarchy to ensure coordination between each level. The proposed methods provide novel insights for both the reinforcement learning research community and for developers of aerospace automatic control system.","Reinforcement Learning; Aerospace Systems; Optimal Adaptive Control; Approximate Dynamic Programming; Adaptive Critic Designs; Incremental Model; Nonlinear Systems; Partial Observability; Hierarchical Reinforcement Learning; HybridMethods","en","doctoral thesis","","978-94-6366-021-1","","","","","","","","","Control & Simulation","","",""
"uuid:b867135c-0df5-439a-a0f7-702d4f67a593","http://resolver.tudelft.nl/uuid:b867135c-0df5-439a-a0f7-702d4f67a593","On the stability relations between tidal asymmetry and morphologies of tidal basins and estuaries","Zhou, Zeng; Coco, Giovanni (The University of Auckland); Townend, Ian (University of Southampton); Gong, Zheng; Wang, Zhengbing (TU Delft Coastal Engineering); Zhang, Changkuan","","2018","Simple stability relationships are practically useful to provide a rapid assessment of coastal and estuarine landforms in response to human interventions and long‐term climate change. In this contribution, we review a variety of simple stability relationships which are based on the analysis of tidal asymmetry (shortened to “TA”). Most of the existing TA‐based stability relationships are derived using the one‐dimensional tidal flow equations assuming a certain regular shape of the tidal channel cross‐sections. To facilitate analytical solutions, specific assumptions inevitably need to be made e.g. by linearising the friction term and dropping some negligible terms in the tidal flow equations. We find that three major types of TA‐based stability relationships have been proposed between three non‐dimensional channel geometric ratios (represented by the ratio of channel widths, ratio of wet surface areas and ratio of storage volumes) and the tide‐related parameter a/h (i.e. the ratio between tidal amplitude and mean water depth). Based on established geometric relations, we use these non‐dimensional ratios to re‐state the existing relationships so that they are directly comparable. Available datasets are further extended to examine theutility of these TA‐based relationships. Although a certain agreement is shown for these relationships, we also observe a large scatter of data points which are collected in different types of landscape, hydrodynamic and sedimentologic settings over the world. We discuss in detail the potential reasons for this large scatter and subsequently elaborate on the limited applicability of the various TA‐based stability relationships for practical use. We highlight the need to delve further into what constitutes equilibrium and what is needed to develop more robust measures to determine the morphological state of these systems.","tidal basins; estuarine morphologies; tidal asymmetry; stability relationships","en","journal article","","","","","","","","2019-04-01","","","Coastal Engineering","","",""
"uuid:4c147dd8-50a5-4c60-8c1d-53671cf8e1e2","http://resolver.tudelft.nl/uuid:4c147dd8-50a5-4c60-8c1d-53671cf8e1e2","Reservoir monitoring using borehole radars to improve oil recovery: Suggestions from 3D electromagnetic and fluid modeling","Zhou, F. (TU Delft Applied Geophysics and Petrophysics; China University of Geosciences, Wuhan); Miorali, M. (TU Delft Applied Geophysics and Petrophysics); Slob, E.C. (TU Delft Applied Geophysics and Petrophysics); Hu, Xiangyun (China University of Geosciences, Wuhan)","","2018","The recently developed smart well technology allows for sectionalized production control by means of downhole inflow control valves and monitoring devices. We consider borehole radars as permanently installed downhole sensors to monitor fluid evolution in reservoirs, and it provides the possibility to support a proactive control for smart well production. To investigate the potential of borehole radar on monitoring reservoirs, we establish a 3D numerical model by coupling electromagnetic propagation and multiphase flow modeling in a bottom-water drive reservoir environment. Simulation results indicate that time-lapse downhole radar measurements can capture the evolution of water and oil distributions in the proximity (order of meters) of a production well, and reservoir imaging with an array of downhole radars successfully reconstructs the profile of a flowing water front. With the information of reservoir dynamics, a proactive control procedure with smart well production is conducted. This method observably delays the water breakthrough and extends the water-free recovery period. To assess the potential benefits that borehole radar brings to hydrocarbon recovery, three production strategies are simulated in a thin oil rim reservoir scenario, i.e., a conventional well production, a reactive production, and a combined production supported by borehole radar monitoring. Relative to the reactive strategy, the combined strategy further reduces cumulative water production by 66.89%, 1.75%, and 0.45% whereas it increases cumulative oil production by 4.76%, 0.57%, and 0.31%, in the production periods of 1 year, 5 years, and 10 years, respectively. The quantitative comparisons reflect that the combined production strategy has the capability of accelerating oil production and suppressing water production, especially in the early stage of production. We suggest that borehole radar is a promising reservoir monitoring technology, and it has the potential to improve oil recovery efficiency.","Borehole geophysics; Ground-penetrating radar (gpr); Permanent reservoir monitoring","en","journal article","","","","","","","","","","","Applied Geophysics and Petrophysics","","",""
"uuid:5a4d2b64-36f9-4ba3-8b6c-22ddb66676c0","http://resolver.tudelft.nl/uuid:5a4d2b64-36f9-4ba3-8b6c-22ddb66676c0","A 0.7-V 0.43-pJ/cycle Wakeup Timer based on a Bang-bang Digital-Intensive frequency-Locked-Loop for IoT Applications","Ding, Ming (Holst Centre); Zhou, Zhihao (Student TU Delft); Liu, Yao-Hong (Holst Centre); Traferro, Stefano (Holst Centre); Bachmann, Christian (Holst Centre); Philips, Kathleen (Holst Centre); Sebastiano, F. (TU Delft (OLD)Applied Quantum Architectures)","","2018","A 40-nm CMOS wakeup timer employing a bang-bang digital-intensive frequency-locked loop for Internet-of-Things applications is presented. A self-biased ΣΔ digitally controlled oscillator (DCO) is locked to an RC time constant via a single-bit chopped comparator and a digital loop filter. Such highly digitized architecture fully exploits the advantages of advanced CMOS processes, thus enabling operation down to 0.7 V and a small area (0.07 mm 2 ). Most circuitry operates at 32× lower frequency than the DCO in order to reduce the total power consumption down to 181 nW. High frequency accuracy and a 10× enhancement of long-term stability is achieved by the adoption of chopping to reduce the effect of comparator offset and 1/f noise and by the use of ΣΔ modulation to improve the DCO resolution. The proposed timer achieves the best energy efficiency (0.43 pJ/cycle at 417 kHz) over prior art while keeping excellent on-par long-term stability (Allan deviation floor <;20 ppm) and temperature stability (106 ppm/°C).","Digital-intensive; frequency locked-loop; Internet of Things (IoT); low-power; oscillator; wakeup timer","en","journal article","","","","","","Accepted Author Manuscript","","","","","(OLD)Applied Quantum Architectures","","",""
"uuid:0b3962e3-1fb7-4a6c-b78c-1d457b62d069","http://resolver.tudelft.nl/uuid:0b3962e3-1fb7-4a6c-b78c-1d457b62d069","Hydrostatic analyses of uprighting processes of a capsized and damaged ship","Pan, Dewei; Lin, Chengxin; Zhou, Zhaoxin; Sun, Yuqinag; Sun, Yuhao","","2018","","construction","","journal article","","","","","","","","","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Hydromechanics and Structures","","",""
"uuid:cd500a95-e06b-4cea-924e-569486ae544e","http://resolver.tudelft.nl/uuid:cd500a95-e06b-4cea-924e-569486ae544e","Fault detection and identification for a class of continuous piecewise affine systems with unknown subsystems and partitions","Moustakis, Nikolaos (Student TU Delft); Zhou, Bingyu (Siemens AG; Student TU Delft); Le quang, Thuan (Quy Nhon University); Baldi, S. (TU Delft Team Bart De Schutter)","","2018","This paper establishes a novel online fault detection and identification strategy for a class of continuous piecewise affine (PWA) systems, namely, bimodal and trimodal PWA systems. The main contributions with respect to the state-of-the-art are the recursive nature of the proposed scheme and the consideration of parametric uncertainties in both partitions and in subsystems parameters. In order to handle this situation, we recast the continuous PWA into its max-form representation and we exploit the recursive Newton-Gauss algorithm on a suitable cost function to derive the adaptive laws to estimate online the unknown subsystem parameters, the partitions, and the loss in control authority for the PWA model. The effectiveness of the proposed methodology is verified via simulations applied to the benchmark example of a wheeled mobile robot.","Fault detection and identification; Online parameter estimation; Piecewise affine unknown systems; Unknown partitions","en","journal article","","","","","","","","","","","Team Bart De Schutter","","",""
"uuid:0fe581d0-6f25-42eb-9d0e-ed08a766f4f7","http://resolver.tudelft.nl/uuid:0fe581d0-6f25-42eb-9d0e-ed08a766f4f7","Autonomous Ships: Nautical Traffic in Ports","Zhou, Y. (TU Delft Rivers, Ports, Waterways and Dredging Engineering); Bellsola Olba, X. (TU Delft Transport and Planning)","","2018","With ongoing trade globalization, waterborne cargo transportation has notably grown in recent years. Due to the growth in ship sizes, with lower manoeuvrability, and higher flows, the safety in these confined areas needs to be guaranteed. Nautical traffic operations in ports are now impacted by more data availability and the disruption of automation processes, and port stakeholders need to adapt to these changes.","","en","journal article","","","","","","","","2019-09-01","","","Rivers, Ports, Waterways and Dredging Engineering","","",""
"uuid:3a166b5d-2315-4ab3-a684-c4c15ae28865","http://resolver.tudelft.nl/uuid:3a166b5d-2315-4ab3-a684-c4c15ae28865","A university building test case for occupancy-based building automation","Swaminathan, Siva (Student TU Delft); Wang, X. (TU Delft Team Bart De Schutter; China State Shipbuilding Corporation); Zhou, Bingyu (Siemens AG); Baldi, S. (TU Delft Team Bart De Schutter)","","2018","Heating, ventilation and air-conditioning (HVAC) units in buildings form a system-of-subsystems entity that must be accurately integrated and controlled by the building automation system to ensure the occupants' comfort with reduced energy consumption. As control of HVACs involves a standardized hierarchy of high-level set-point control and low-level Proportional-Integral-Derivative (PID) controls, there is a need for overcoming current control fragmentation without disrupting the standard hierarchy. In this work, we propose a model-based approach to achieve these goals. In particular: The set-point control is based on a predictive HVAC thermal model, and aims at optimizing thermal comfort with reduced energy consumption; the standard low-level PID controllers are auto-tuned based on simulations of the HVAC thermal model, and aims at good tracking of the set points. One benefit of such control structure is that the PID dynamics are included in the predictive optimization: in this way, we are able to account for tracking transients, which are particularly useful if the HVAC is switched on and off depending on occupancy patterns. Experimental and simulation validation via a three-room test case at the Delft University of Technology shows the potential for a high degree of comfort while also reducing energy consumption.","Demand side management; Heating ventilation and air-conditioning (hvac); Occupancy-based control; Optimization; Predicted mean vote (pmv)","en","journal article","","","","","","","","","","","Team Bart De Schutter","","",""
"uuid:525dd30d-bcd0-42a2-94fe-1b1050ee850f","http://resolver.tudelft.nl/uuid:525dd30d-bcd0-42a2-94fe-1b1050ee850f","Nonlinear frequency division multiplexing with b-modulation: Shifting the energy barrier","Gui, Tao (The Hong Kong Polytechnic University); Zhou, Gai (The Hong Kong Polytechnic University); Lu, Chao (The Hong Kong Polytechnic University); Lau, Alan Pak Tao (The Hong Kong Polytechnic University); Wahls, S. (TU Delft Team Sander Wahls)","","2018","The recently proposed b-modulation method for nonlinear Fourier transform-based fiber-optic transmission offers explicit control over the duration of the generated pulses and therewith solves a longstanding practical problem. The currently used b-modulation however suffers from a fundamental energy barrier. There is a limit to the energy of the pulses, in normalized units, that can be generated. In this paper, we discuss how the energy barrier can be shifted by proper design of the carrier waveform and the modulation alphabet. In an experiment, it is found that the improved b-modulator achieves both a higher Q-factor and a further reach than a comparable conventional b-modulator. Furthermore, it performs significantly better than conventional approaches that modulate the reflection coefficient.","","en","journal article","","","","","","","","","","","Team Sander Wahls","","",""
"uuid:70995006-c9b3-4dac-a199-9eb3f9263232","http://resolver.tudelft.nl/uuid:70995006-c9b3-4dac-a199-9eb3f9263232","Building classification of VHR airborne stereo images using fully convolutional networks and free training samples","Chen, Y. (Student TU Delft); Gao, W. (TU Delft Urban Data Science); Widyaningrum, E. (TU Delft Optical and Laser Remote Sensing); Zheng, M. (TU Delft OLD Department of GIS Technology); Zhou, K. (TU Delft Optical and Laser Remote Sensing)","","2018","Semantic segmentation, especially for buildings, from the very high resolution (VHR) airborne images is an important task in urban mapping applications. Nowadays, the deep learning has significantly improved and applied in computer vision applications. Fully Convolutional Networks (FCN) is one of the tops voted method due to their good performance and high computational efficiency. However, the state-of-art results of deep nets depend on the training on large-scale benchmark datasets. Unfortunately, the benchmarks of VHR images are limited and have less generalization capability to another area of interest. As existing high precision base maps are easily available and objects are not changed dramatically in an urban area, the map information can be used to label images for training samples. Apart from object changes between maps and images due to time differences, the maps often cannot perfectly match with images. In this study, the main mislabeling sources are considered and addressed by utilizing stereo images, such as relief displacement, different representation between the base map and the image, and occlusion areas in the image. These free training samples are then fed to a pre-trained FCN. To find the better result, we applied fine-tuning with different learning rates and freezing different layers. We further improved the results by introducing atrous convolution. By using free training samples, we achieve a promising building classification with 85.6% overall accuracy and 83.77% F1 score, while the result from ISPRS benchmark by using manual labels has 92.02% overall accuracy and 84.06% F1 score, due to the building complexities in our study area.","Atrous convolution; Base map; Building classification; FCN; Fine tuning; Free training samples; Mislabels; VHR airborne stereo images","en","journal article","","","","","","","","","","","Urban Data Science","","",""
"uuid:27312c18-c381-4cd6-be41-a712933becf5","http://resolver.tudelft.nl/uuid:27312c18-c381-4cd6-be41-a712933becf5","A comprehensive investigation of the strengthening effects of dislocations, texture and low and high angle grain boundaries in ultrafine grained AA6063 aluminum alloy","Najafi, S. (Iran University of Science and Technology); Eivani, A. R. (Iran University of Science and Technology); Samaee, M. (Iran University of Science and Technology); Jafarian, H. R. (Iran University of Science and Technology); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2018","The effect of equal channel angular pressing (ECAP) on the microstructure and mechanical properties of AA6063 aluminum alloy was investigated. For this purpose, samples of AA6063 aluminum alloy were deformed up to 10 passes using ECAP and the evolution of microstructure, texture and dislocation density was investigated. It was found that the dislocation density increased and cells mostly surrounded by low angle boundaries (LABs) formed after 2 passes ECAP. Increasing the dislocation density continued with further processing and reached a maximum at the 4th ECAP pass. With further deformation to 6 passes, the dislocation density reduced, the fraction of high angle boundaries (HABs) increased and the averages of cell size and grain size reduced, significantly, which indicated the occurrence of grain refinement. However, a slight increase in dislocation density, average cell size (ACS) and average grain size (AGS), indicating coarsening, occurred when 10 passes of ECAP are imposed. Hardness, yield (YS) and ultimate tensile strength (UTS) increased continuously although the most significant enhancement occurred after 2 passes of ECAP. Investigating the correlation between the microstructure and mechanical properties indicated that Hall-Petch relationship was valid for ultrafine grained AA6063 before the coarsening started provided that the property of interest was correlated to average cell size but not the average grain size.","AA6063; Mechanical properties; Microstructure; Ultrafine grain","en","journal article","","","","","","Accepted Author Manuscript","","2020-01-04","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:9ce9e93c-06b0-43c9-93b7-3f6d66085a1a","http://resolver.tudelft.nl/uuid:9ce9e93c-06b0-43c9-93b7-3f6d66085a1a","Joint multi-policy behavior estimation and receding-horizon trajectory planning for automated urban driving","Zhou, Bingyu (Student TU Delft); Schwarting, Wilko (Massachusetts Institute of Technology); Rus, Daniela (Massachusetts Institute of Technology); Alonso-Mora, J. (TU Delft Learning & Autonomous Control)","Lynch, Kevin (editor)","2018","When driving in urban environments, an autonomous vehicle must account for the interaction with other traffic participants. It must reason about their future behavior, how its actions affect their future behavior, and potentially
consider multiple motion hypothesis. In this paper we introduce a method for joint behavior estimation and trajectory planning that models interaction and multi-policy decisionmaking. The method leverages Partially Observable Markov Decision Processes to estimate the behavior of other traffic participants given the planned trajectory for the ego-vehicle, and Receding-Horizon Control for generating safe trajectories for the ego-vehicle. To achieve safe navigation we introduce chance constraints over multiple motion policies in the recedinghorizon planner. These constraints account for uncertainty over
the behavior of other traffic participants. The method is capable of running in real-time and we show its performance and good scalability in simulated multi-vehicle intersection scenarios.","","en","conference paper","IEEE","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2019-03-13","","","Learning & Autonomous Control","","",""
"uuid:db138ad4-e87c-428c-87ed-ad70a0b30a1a","http://resolver.tudelft.nl/uuid:db138ad4-e87c-428c-87ed-ad70a0b30a1a","Induction heating-assisted compaction in porous asphalt pavements: A computational study","Zhou, C. (TU Delft Pavement Engineering; Dalian University of Technology); Liu, X. (TU Delft Pavement Engineering); Apostolidis, P. (TU Delft Pavement Engineering); Scarpas, Athanasios (TU Delft Pavement Engineering); He, Liang (Chongqing Jiaotong University)","","2018","Low temperature asphalt (LTA) technologies, such as warm-mixed asphalt mixes, are utilized in the paving industry to lower energy demands and greenhouse gas emissions during asphalt mixing and pavement construction. However, the asphalt mixes developed that incorporate LTA additives are more sensitive than hot-mixed asphalts to temperature reduction during compaction, which leads to inadequate compaction and subsequent poor pavement performance. The induction heating-assisted compaction of pavement structures appears to be an effective way to ameliorate such issues and to improve mix compactability at lower temperatures. Considering that induction-assisted compaction is a complex process, a computational methodology is proposed in this paper. A porous asphalt concrete mix was considered as case material. For the pavement compaction analyses after induction, the temperature field generated by electromagnetic induction was predicted and the material parameters of asphalt mortar were adjusted. The effect of induction heating on asphalt compaction effectiveness, the tendency of mix density changing, the increase in compactor passes, and the influence of temperature on compaction at different locations in the pavement were studied as well.","Computational tools; Induction heating; Pavement compaction; Porous asphalt mixes","en","journal article","","","","","","","","","","","Pavement Engineering","","",""
"uuid:7b88ee07-366a-4289-9365-24c410412313","http://resolver.tudelft.nl/uuid:7b88ee07-366a-4289-9365-24c410412313","Biodegradation and mechanical behavior of an advanced bioceramic-containing Mg matrix composite synthesized through in-situ solid-state oxidation","Naddaf Dezfuli, S. (TU Delft (OLD) MSE-1); Brouwer, J.C. (TU Delft (OLD) MSE-1); Mol, J.M.C. (TU Delft (OLD) MSE-6); van der Helm, F.C.T. (TU Delft Biomechatronics & Human-Machine Control); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2018","Recent studies have shown great potential of Mg matrix composites for biodegradable orthopedic devices. However, the poor structural integrity of these composites, which results in excessive localized corrosion and premature mechanical failure, has hindered their widespread applications. In this research, an in-situ Powder Metallurgy (PM) method was used to fabricate a novel biodegradable Mg-bredigite composite and to achieve enhanced chemical interfacial locking between the constituents by triggering a solid-state thermochemical reaction between Mg and bredigite particles. The reaction resulted in a highly densified and integrated microstructure, which prevented corrosion pits from propagating when the composite was immersed in a physiological solution. In addition, chemical interlocking between the constituents prohibited interparticle fracture and subsequent surface delamination during compression testing, enabling the composite to withstand larger plastic deformation before mechanical failure. Furthermore, the composite was proven to be biocompatible and capable of maintaining its ultimate compressive strength in the strength range of cortical bone after 25-day immersion in DMEM. The research provided the necessary information to guide further research towards the development of a next generation of biodegradable Mg matrix composites with enhanced chemical interlocking.","Biocompatibility; Chemical interlocking; Composite; Degradation; Magnesium; Mechanical property","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2018-09-01","","","(OLD) MSE-1","","",""
"uuid:5a8fa606-444f-4cd8-b364-5db930111a32","http://resolver.tudelft.nl/uuid:5a8fa606-444f-4cd8-b364-5db930111a32","Coupling dynamics of epidemic spreading and information diffusion on complex networks","Zhan, X. (TU Delft Multimedia Computing; Hangzhou Normal University); Liu, Chuang (Hangzhou Normal University); Zhou, Ge (Hangzhou Normal University; Shanghai Jiao Tong University); Zhang, Zi-Ke (Hangzhou Normal University; Shanghai Jiao Tong University); Sun, Gui-Quan (Shanxi University); Zhu, Jonathan J. H. (City University of Hong Kong); Jin, Zhen (Shanxi University)","","2018","The interaction between disease and disease information on complex networks has facilitated an interdisciplinary research area. When a disease begins to spread in the population, the corresponding information would also be transmitted among individuals, which in turn influence the spreading pattern of the disease. In this paper, firstly, we analyze the propagation of two representative diseases (H7N9 and Dengue fever) in the real-world population and their corresponding information on Internet, suggesting the high correlation of the two-type dynamical processes. Secondly, inspired by empirical analyses, we propose a nonlinear model to further interpret the coupling effect based on the SIS (Susceptible-Infected-Susceptible) model. Both simulation results and theoretical analysis show that a high prevalence of epidemic will lead to a slow information decay, consequently resulting in a high infected level, which shall in turn prevent the epidemic spreading. Finally, further theoretical analysis demonstrates that a multi-outbreak phenomenon emerges via the effect of coupling dynamics, which finds good agreement with empirical results. This work may shed light on the in-depth understanding of the interplay between the dynamics of epidemic spreading and information diffusion.","Coupling dynamics; Epidemic spreading; Information diffusion","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","","","","Multimedia Computing","","",""
"uuid:86266ed1-b6db-4f87-8f6f-e89fdb90df7b","http://resolver.tudelft.nl/uuid:86266ed1-b6db-4f87-8f6f-e89fdb90df7b","Improvement of mechanical performance of bioresorbable magnesium alloy coronary artery stents through stent pattern redesign","Wang, Qian (Tsinghua University); Fang, Gang (Tsinghua University); Zhao, Ying Hong (Shanghai Bio-heart Biological Technology Co. Ltd.); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2018","Optimized stent pattern design can effectively enhance the mechanical performance of magnesium alloy stents by adjusting strain distribution and evolution during stent deformation, thereby overcoming the limitations imposed by the intrinsic mechanical properties of magnesium alloys. In the present study, a new stent design pattern for magnesium alloys was proposed and compared to two existing stent design patterns. Measures of the mechanical performance of these three stents, including crimping and expanding deformability, radial scaffolding capacity, radial recoil and bending flexibility, were determined. Three-dimensional finite element (FE) models were built to predict the mechanical performance of the stents with the three design patterns and to assist in understanding the experimental results. The results showed that, overall, the stent with the new design pattern was superior to the stents based on the existing designs, though the expanding capacity of the newly designed stent still needed to be improved.","Bioresorbable stent; Deformation behavior; Finite element analysis; Magnesium; Mechanical property","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:b72e36e4-b0c3-4b12-9998-79adc48ed4bf","http://resolver.tudelft.nl/uuid:b72e36e4-b0c3-4b12-9998-79adc48ed4bf","Applying agent based modelling and simulation for domino effect assessment in the chemical industries","Zhang, L. (TU Delft Safety and Security Science); Landucci, Gabriele (University of Pisa; Universiteit Leiden); Reniers, G.L.L.M.E. (TU Delft Safety and Security Science); Ovidi, Federica (University of Pisa); Khakzad, N. (TU Delft Safety and Security Science); Zhou, Jianfeng (Guangdong University of Technology)","","2018","The propagation of accidents among process units may cause amplification of accident magnitude, resulting in a domino effect chain. Several catastrophic accidents occurred in the process and chemical industry presented these features. Hence, research efforts have been given to the analysis of the domino effects in order to enhance prevention and mitigation strategies. In this work, challenges of analysing domino effects in the chemical industries are discussed, highlighting that quantitative analytic approaches suffer from the complexity on assessing domino effects, especially when dealing with simultaneous accidents propagating among multiple units. Therefore, a bottom-up modelling approach, namely, the agent based modelling and simulation (ABM&S) approach, is introduced for analysing domino effects. Moreover, a prototype model for assessing domino effects in the chemical industries by using agent based modelling and simulation (DAMS) is given and further extensions of the prototype model is also discussed, highlighting the potential benefits.","","en","book chapter","Italian Association of Chemical Engineering","","","","","","","","","","Safety and Security Science","","",""
"uuid:0a1acd06-9e1c-4106-8cb1-5202cf2f8aa5","http://resolver.tudelft.nl/uuid:0a1acd06-9e1c-4106-8cb1-5202cf2f8aa5","Insight into Eu redox and Pr3+ 5d emission in KSrPO4 by VRBE scheme construction","Zhou, Rongfu (Sun Yat-sen University); Lin, Litian (Sun Yat-sen University); Liu, Chunmeng (Sun Yat-sen University); Dorenbos, P. (TU Delft RST/Fundamental Aspects of Materials and Energy); Tao, Ye (Institute of High Energy Physics Chinese Academy of Science); Huang, Yan (Institute of High Energy Physics Chinese Academy of Science); Liang, Hongbin (Sun Yat-sen University)","","2018","A series of Ln-doped KSrPO4 (Ln = Ce3+, Eu3+, Eu2+, Pr3+) phosphors are prepared through a high-temperature solid-state method. The KSrPO4 compound is confirmed to possess a β-K2SO4 structure with the Pnma group by Rietveld refinement, and the temperature-dependent lattice parameters are investigated with the powder X-ray diffraction results at different temperatures. Ce3+ and Eu3+ ions are introduced to probe the crystal field strength (CFS) and the lanthanide site symmetry by using VUV-UV-vis spectroscopy. The temperature-dependent luminescence properties of KSrPO4: Ce3+/Eu2+ exhibit an excellent thermal stability of Ce3+/Eu2+ luminescence. Based on the VUV-UV-vis spectra of Ce3+ and Eu3+ doped KSrPO4, the vacuum referred binding energy (VRBE) scheme is constructed to understand the redox properties of Eu, the 5d energy levels of Pr3+ and the thermal quenching characteristics of Ce3+ and Eu2+ luminescence.","","en","journal article","","","","","","Accepted Author Manuscript","","2019-01-02","","","RST/Fundamental Aspects of Materials and Energy","","",""
"uuid:9e5b9432-23dd-4417-9cbd-45ec02c7535c","http://resolver.tudelft.nl/uuid:9e5b9432-23dd-4417-9cbd-45ec02c7535c","Additively manufactured biodegradable porous iron","Li, Y. (TU Delft Biomaterials & Tissue Biomechanics); Jahr, H. (Medizinische Fakultat und Universitats Klinikum Aachen; Maastricht UMC); Lietaert, K. (Katholieke Universiteit Leuven; 3D Systems); Pavanram, P. (Medizinische Fakultat und Universitats Klinikum Aachen); Yilmaz, A. (TU Delft (OLD) MSE-6); Fockaert, L.I. (TU Delft (OLD) MSE-6); Leeflang, M.A. (TU Delft Biomaterials & Tissue Biomechanics); Pouran, B. (TU Delft Biomaterials & Tissue Biomechanics; University Medical Center Utrecht); Gonzalez Garcia, Y. (TU Delft (OLD) MSE-6); Weinans, Harrie (TU Delft Biomaterials & Tissue Biomechanics; University Medical Center Utrecht); Mol, J.M.C. (TU Delft (OLD) MSE-6); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2018","Additively manufactured (AM) topologically ordered porous metallic biomaterials with the proper biodegradation profile offer a unique combination of properties ideal for bone regeneration. These include a fully interconnected porous structure, bone-mimicking mechanical properties, and the possibility of fully regenerating bony defects. Most of such biomaterials are, however, based on magnesium and, thus, degrade too fast. Here, we present the first report on topologically ordered porous iron made by Direct Metal Printing (DMP). The topological design was based on a repetitive diamond unit cell. We conducted a comprehensive study on the in vitro biodegradation behavior (up to 28 days), electrochemical performance, time-dependent mechanical properties, and biocompatibility of the scaffolds. The mechanical properties of AM porous iron (E = 1600–1800 MPa) were still within the range of the values reported for trabecular bone after 28 days of biodegradation. Electrochemical tests showed up to ≈12 times higher rates of biodegradation for AM porous iron as compared to that of cold-rolled (CR) iron, while only 3.1% of weight loss was measured after 4 weeks of immersion tests. The biodegradation mechanisms were found to be topology-dependent and different between the periphery and central parts of the scaffolds. While direct contact between MG-63 cells and scaffolds revealed substantial and almost instant cytotoxicity in static cell culture, as compared to Ti-6Al-4V, the cytocompatibility according to ISO 10993 was reasonable in in vitro assays for up to 72 h. This study shows how DMP could be used to increase the surface area and decrease the grain sizes of topologically ordered porous metallic biomaterials made from metals that are usually considered to degrade too slowly (e.g., iron), opening up many new opportunities for the development of biodegradable metallic biomaterials. Statement of Significance: Biodegradation in general and proper biodegradation profile in particular are perhaps the most important requirements that additively manufactured (AM) topologically ordered porous metallic biomaterials should offer in order to become the ideal biomaterial for bone regeneration. Currently, most biodegradable metallic biomaterials are based on magnesium, which degrade fast with gas generation. Here, we present the first report on topologically ordered porous iron made by Direct Metal Printing (DMP). We also conducted a comprehensive study on the biodegradation behavior, electrochemical performance, biocompatibility, and the time evolution of the mechanical properties of the implants. We show that these implants possess bone-mimicking mechanical properties, accelerated degradation rate, and reasonable cytocompatibility, opening up many new opportunities for the development of iron-based biodegradable materials.","Additive manufacturing; Biocompatibility; Biodegradation; Direct metal printing; Iron scaffolds; Mechanical property","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2019-01-06","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:a3298a3e-45ee-4e40-a154-70d665ed57d0","http://resolver.tudelft.nl/uuid:a3298a3e-45ee-4e40-a154-70d665ed57d0","Effect of porosity variation strategy on the performance of functionally graded Ti-6Al-4V scaffolds for bone tissue engineering","Zhang, Xiang Yu (Tsinghua University); Fang, Gang (Tsinghua University); Xing, Lei Lei (Tsinghua University); Liu, Wei (Tsinghua University); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2018","Functionally graded scaffold (FGS) is designed to mimic the morphology, mechanical and biological properties of natural bone closely. Porosity variation strategy between different regions in FGS plays a crucial role in influencing its mechanical and biological performance. A combination of modeling tool and scripting language can effectively enhance the ability to optimize FGS design. This study was aimed at determining the effect of porosity variation strategy on the mechanical performance and permeability of the as-built and as-heat-treated FGSs. Ti-6Al-4V FGSs with sizes of 10 × 10 × 15 mm and diamond lattice structures were designed and fabricated by means of selective laser melting. A wide range of porosities in the FGSs (38–75%) were achieved by applying six different porosity variation strategies. The elastic modulus (3.7–5.7 GPa) and yield strength (27.1–84.7 MPa) of the as-built FGSs were found to vary between the corresponding mechanical properties of cancellous bone and cortical bone. Heat treatment reduced the strengths by 13–56%. Porosity variation strategy strongly affected the deformation behavior and failure mechanisms of the FGSs. The sigmoid function-controlled FGSs showed gradual failure behavior and sample Sigk0.5b8 showed superior overall performance. The results demonstrated that porosity variation strategy is a feasible means for tailor design of FGS.","Functionally graded scaffold; Mechanical properties; Permeability; Selective laser melting; Ti-6Al-4V","en","journal article","","","","","","Accepted Author Manuscript","","2020-08-08","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:2e269108-ede2-4d99-9116-e80dd92cbb6f","http://resolver.tudelft.nl/uuid:2e269108-ede2-4d99-9116-e80dd92cbb6f","Video Captioning by Adversarial LSTM","Yang, Yang (University of Electronic Science and Technology of China); Zhou, Jie (University of Electronic Science and Technology of China); Ai, Jiangbo (University of Electronic Science and Technology of China); Bin, Yi (University of Electronic Science and Technology of China); Hanjalic, A. (TU Delft Intelligent Systems); Shen, Heng Tao (University of Electronic Science and Technology of China)","","2018","In this paper, we propose a novel approach to video captioning based on adversarial learning and long short-term memory (LSTM). With this solution concept, we aim at compensating for the deficiencies of LSTM-based video captioning methods that generally show potential to effectively handle temporal nature of video data when generating captions but also typically suffer from exponential error accumulation. Specifically, we adopt a standard generative adversarial network (GAN) architecture, characterized by an interplay of two competing processes: a 'generator' that generates textual sentences given the visual content of a video and a 'discriminator' that controls the accuracy of the generated sentences. The discriminator acts as an 'adversary' toward the generator, and with its controlling mechanism, it helps the generator to become more accurate. For the generator module, we take an existing video captioning concept using LSTM network. For the discriminator, we propose a novel realization specifically tuned for the video captioning problem and taking both the sentences and video features as input. This leads to our proposed LSTM-GAN system architecture, for which we show experimentally to significantly outperform the existing methods on standard public datasets.","adversarial training; LSTM; Video captioning","en","journal article","","","","","","Accepted author manuscript","","","","Intelligent Systems","","","",""
"uuid:84176c3b-9d3f-44ef-ac1b-ce5579440c64","http://resolver.tudelft.nl/uuid:84176c3b-9d3f-44ef-ac1b-ce5579440c64","The role of storm scale, position and movement in controlling urban flood response","ten Veldhuis, Marie-claire (TU Delft Water Resources; Princeton University); Zhou, Zhengzheng (Princeton University; Tongji University; UNEP-Tongji Institute of Environment for Sustainable Development); Yang, Long (Princeton University); Liu, Shuguang (UNEP-Tongji Institute of Environment for Sustainable Development); Smith, James (Princeton University)","","2018","The impact of spatial and temporal variability of rainfall on hydrological response remains poorly understood, in particular in urban catchments due to their strong variability in land use, a high degree of imperviousness and the presence of stormwater infrastructure. In this study, we analyze the effect of storm scale, position and movement in relation to basin scale and flow-path network structure on urban hydrological response. A catalog of 279 peak events was extracted from a high-quality observational dataset covering 15 years of flow observations and radar rainfall data for five (semi)urbanized basins ranging from 7.0 to 111.1km2 in size. Results showed that the largest peak flows in the event catalog were associated with storm core scales exceeding basin scale, for all except the largest basin. Spatial scale of flood-producing storm events in the smaller basins fell into two groups: Storms of large spatial scales exceeding basin size or small, concentrated events, with storm core much smaller than basin size. For the majority of events, spatial rainfall variability was strongly smoothed by the flow-path network, increasingly so for larger basin size. Correlation analysis showed that position of the storm in relation to the flow-path network was significantly correlated with peak flow in the smallest and in the two more urbanized basins. Analysis of storm movement relative to the flow-path network showed that direction of storm movement, upstream or downstream relative to the flow-path network, had little influence on hydrological response. Slow-moving storms tend to be associated with higher peak flows and longer lag times. Unexpectedly, position of the storm relative to impervious cover within the basins had little effect on flow peaks. These findings show the importance of observation-based analysis in validating and improving our understanding of interactions between the spatial distribution of rainfall and catchment variability.","","en","journal article","","","","","","","","","","","Water Resources","","",""
"uuid:af888805-4d4a-4521-81ed-8a95a98000a9","http://resolver.tudelft.nl/uuid:af888805-4d4a-4521-81ed-8a95a98000a9","Identifying Spreading Sources and Influential Nodes of Hot Events on Social Networks","Zhou, Nan (Hangzhou Normal University); Zhan, X. (TU Delft Multimedia Computing); Ma, Qiang (Hangzhou Normal University); Lin, Song (Hangzhou Normal University); Zhang, Jun (Shanghai Surfing City Information S&T Co. Ltd); Zhang, Zi-Ke (Hangzhou Normal University)","Cherifi, C. (editor); Cherifi, H. (editor); Karsai, M. (editor); Musolesi, M. (editor)","2018","The rapid development of World Wide Web accelerates information spreading in various ways. Thanks to the emergence of multiple social platforms, some events which are not much attractive in the past can become social hot spots nowadays. In this paper, we study the information diffusion process of “IP MAN3 box office fraud”, which is widely diffused in the largest Chinese microblogging system, namely Sina Weibo, in March 2016. Based on the temporal metric we have proposed, we succeed in finding out the sources of the information, and constructing the panorama of the diffusion process. In addition, a portion of nodes that promote the diffusion are identified by using the node importance algorithms. Finally, the users with abnormal behaviors in the process of event development are identified.","Critical nodes identification; Information diffusion; Source tracing","en","conference paper","Springer","","","","","Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2019-12-31","","","Multimedia Computing","","",""
"uuid:91426fab-9bf3-4727-a019-28e9d1eabd21","http://resolver.tudelft.nl/uuid:91426fab-9bf3-4727-a019-28e9d1eabd21","AIS data analysis for the impacts of wind and current on ship behavior in straight waterways","Zhou, Y. (TU Delft Rivers, Ports, Waterways and Dredging Engineering); Daamen, W. (TU Delft Transport and Planning); Vellinga, T. (TU Delft Rivers, Ports, Waterways and Dredging Engineering); Hoogendoorn, S.P. (TU Delft Transport and Planning)","Guedes Soares, Carlos (editor); Teixeira, Ângelo P. (editor)","2017","Due to the increasing ship traffic flow in ports, maritime traffic safety has attracted much atten-tion. In addition to traffic flow, the ship safety in restricted waters is influenced by external navigational fac-tors (visibility, wind and current), encounter situations and human factors on board. In this paper, we investi-gate the effect of navigational factors on ship behavior. The raw AIS data and locally measured visibility, wind, and current data in the port of Rotterdam are collected to investigate the impacts of wind and current on ship speed and path (distance to the starboard bank). The results reveal that the wind mainly affects the paths of ships by the force of cross-wind, while the current impacts the speed over ground of ships when the current is with or against the heading of ship. The impacts on different sizes of ships are different as well. The port side wind has a larger impact on small ships than on large ships, while the impact of starboard side wind is larger for large ships than for small ships. The impact of current on the speed over ground is larger on small ships than large ships, and least on medium ships. The analysis results could assist the port authority in pre-dicting ship traffic in different situations, and be used in the development of a new maritime traffic model to simulate ship behavior while considering the external navigational factors.","AIS data; wind; current; ship behavior","en","conference paper","CRC Press","","","","","","","","","Transport and Planning","Rivers, Ports, Waterways and Dredging Engineering","","",""
"uuid:37df6789-f7f3-4d71-82d4-6ffefc77905d","http://resolver.tudelft.nl/uuid:37df6789-f7f3-4d71-82d4-6ffefc77905d","Shadow detection from VHR aerial images in urban area by using 3D city models and a decision fusion approach","Zhou, K. (TU Delft Optical and Laser Remote Sensing); Gorte, B.G.H. (TU Delft Optical and Laser Remote Sensing)","Li, D. (editor); Gong, J. (editor); Yang, B. (editor)","2017","In VHR(very high resolution) aerial images, shadows indicating height information are valuable for validating or detecting changes on an existing 3D city model. In the paper, we propose a novel and full automatic approach for shadow detection from VHR images. Instead of automatic thresholding, the supervised machine learning approach is expected with better performance on shadow detection, but it requires to obtain training samples manually. The shadow image reconstructed from an existing 3D city model can provide free training samples with large variety. However, as the 3D model is often not accuracy, incomplete and outdated, a small portion of training samples are mislabeled. The erosion morphology is provided to remove boundary pixels which have high mislabeling possibility from the reconstructed image. Moreover, the quadratic discriminant analysis (QDA) which is resistant to the mislabeling is chosen. Further, two feature domains, RGB and ratio of the hue over the intensity, are analyzed to have complementary effects on better detecting different objects. Finally, a decision fusion approach is proposed to combine the results wisely from preliminary classifications from two feature domains. The fuzzy membership is a confidence measurement and determines the way of making decision, in the meanwhile the memberships are weighted by an entropy measurements to indicate their certainties. The experimental results on two cities in the Netherlands demonstrate that the proposed approach outperforms the two separate classifiers and two stacked-vector fusion approaches.","3D city model; Decision fusion; Entropy; Free training samples; Fuzzy membership; Mislabel; QDA; VHR aerial images","en","conference paper","","","","","","","","","","","Optical and Laser Remote Sensing","","",""
"uuid:8cc79157-b721-4c1c-9f13-47137f9ffd14","http://resolver.tudelft.nl/uuid:8cc79157-b721-4c1c-9f13-47137f9ffd14","In situ soil permeability reduction through Al and OM precipitation as a geoengineering tool for dike stabilization: (Abstract)","Zhou, J. (Delft University of technology); Laumann, S. (Delft University of technology); Heimovaara, T.J. (Delft University of technology)","","2017","","podzolization; SoSEAL; in situ permeability reduction; building with nature","en","conference paper","","","","","","","","","","","","","",""
"uuid:42696668-8114-47c8-b5ff-7a5b36cb7f2d","http://resolver.tudelft.nl/uuid:42696668-8114-47c8-b5ff-7a5b36cb7f2d","A new method to estimate changes in glacier surface elevation based on polynomial fitting of sparse ICESat—GLAS footprints","Huang, Tianjin (Chinese Academy of Sciences; Joint Center for Global Change Studies); Jia, Li (Chinese Academy of Sciences; Joint Center for Global Change Studies); Menenti, M. (TU Delft Optical and Laser Remote Sensing; Chinese Academy of Sciences); Lu, Jing (Chinese Academy of Sciences; Joint Center for Global Change Studies); Zhou, Jie (Chinese Academy of Sciences; Joint Center for Global Change Studies); Hu, Guangcheng (Chinese Academy of Sciences; Joint Center for Global Change Studies)","","2017","We present in this paper a polynomial fitting method applicable to segments of footprints measured by the Geoscience Laser Altimeter System (GLAS) to estimate glacier thickness change. Our modification makes the method applicable to complex topography, such as a large mountain glacier. After a full analysis of the planar fitting method to characterize errors of estimates due to complex topography, we developed an improved fitting method by adjusting a binary polynomial surface to local topography. The improved method and the planar fitting method were tested on the accumulation areas of the Naimona’nyi glacier and Yanong glacier on along-track facets with lengths of 1000 m, 1500 m, 2000 m, and 2500 m, respectively. The results show that the improved method gives more reliable estimates of changes in elevation than planar fitting. The improved method was also tested on Guliya glacier with a large and relatively flat area and the Chasku Muba glacier with very complex topography. The results in these test sites demonstrate that the improved method can give estimates of glacier thickness change on glaciers with a large area and a complex topography. Additionally, the improved method based on GLAS Data and Shuttle Radar Topography Mission-Digital Elevation Model (SRTM-DEM) can give estimates of glacier thickness change from 2000 to 2008/2009, since it takes the 2000 SRTM-DEM as a reference, which is a longer period than 2004 to 2008/2009, when using the GLAS data only and the planar fitting method.","Glacier thickness change; ICESat; Polynomial fitting method","en","journal article","","","","","","","","","","","Optical and Laser Remote Sensing","","",""
"uuid:63bfbf38-11e0-413c-8e5c-2538b3ddf384","http://resolver.tudelft.nl/uuid:63bfbf38-11e0-413c-8e5c-2538b3ddf384","The complexities of urban flood response: Flood frequency analyses for the Charlotte metropolitan region","Zhou, Zhengzheng (Tongji University; Princeton University; UNEP-Tongji Institute of Environment for Sustainable Development); Smith, James A. (Princeton University); Yang, Long (Princeton University); Baeck, Mary Lynn (Princeton University); Chaney, Molly (Princeton University); ten Veldhuis, Marie-claire (TU Delft Water Resources); Deng, Huiping (UNEP-Tongji Institute of Environment for Sustainable Development; Tongji University); Liu, Shuguang (Tongji University; UNEP-Tongji Institute of Environment for Sustainable Development)","","2017","We examine urban flood response through data-driven analyses for a diverse sample of “small” watersheds (basin scale ranging from 7.0 to 111.1 km2) in the Charlotte Metropolitan region. These watersheds have experienced extensive urbanization and suburban development since the 1960s. The objective of this study is to develop a broad characterization of land surface and hydrometeorological controls of urban flood hydrology. Our analyses are based on peaks-over-threshold flood data developed from USGS streamflow observations and are motivated by problems of flood hazard characterization for urban regions. We examine flood-producing rainfall using high-resolution (1 km2 spatial resolution and 15 min time resolution), bias-corrected radar rainfall fields that are developed through the Hydro-NEXRAD system. The analyses focus on the 2001–2015 period. The results highlight the complexities of urban flood response. There are striking spatial heterogeneities in flood peak magnitudes, response times, and runoff ratios across the study region. These spatial heterogeneities are mainly linked to watershed scale, the distribution of impervious cover, and storm water management. Contrasting land surface properties also determine the mixture of flood-generating mechanisms for a particular watershed. Warm-season thunderstorm systems and tropical cyclones are main flood agents in Charlotte, with winter/spring storms playing a role in less-urbanized watersheds. The mixture of flood agents exerts a strong impact on the upper tail of flood frequency distributions. Antecedent watershed wetness plays a minor role in urban flood response, compared with less-urbanized watersheds. Implications for flood hazard characterization in urban watersheds and for advances in flood science are discussed.","flood frequency analysis; flood response; urban watersheds","en","journal article","","","","","","","","2018-03-01","","","Water Resources","","",""
"uuid:b63b663b-c6af-450b-ae3a-5b2f8c4d0335","http://resolver.tudelft.nl/uuid:b63b663b-c6af-450b-ae3a-5b2f8c4d0335","Impact of coagulant and flocculant addition to an anaerobic dynamic membrane bioreactor (AnDMBR) treating waste-activated sludge","Kooijman, G. (TU Delft Sanitary Engineering); Lopes, Wilton (Bairro Universitario); Zhou, Z. (Sun Yat-sen University); Guo, H. (TU Delft Sanitary Engineering); de Kreuk, M.K. (TU Delft Sanitary Engineering); Spanjers, H. (TU Delft Sanitary Engineering); van Lier, J.B. (TU Delft Sanitary Engineering)","","2017","In this work, we investigated the effects of flocculation aid (FA) addition to an anaerobic dynamic membrane bioreactor (AnDMBR) (7 L, 35°C) treating waste-activated sludge (WAS). The experiment consisted of three distinct periods. In period 1 (day 1–86), the reactor was operated as a conventional anaerobic digester with a solids retention time (SRT) and hydraulic retention time (HRT) of 24 days. In period 2 (day 86–303), the HRT was lowered to 18 days with the application of a dynamic membrane while the SRT was kept the same. In period 3 (day 303–386), a cationic FA in combination with FeCl3 was added. The additions led to a lower viscosity, which was expected to lead to an increased digestion performance. However, the FAs caused irreversible binding of the substrate, lowering the volatile solids destruction from 32% in period 2 to 24% in period 3. An accumulation of small particulates was observed in the sludge, lowering the average particle size by 50%. These particulates likely caused pore blocking in the cake layer, doubling the trans-membrane pressure. The methanogenic consortia were unaffected. Dosing coagulants and flocculants into an AnDMBR treating sludge leads to a decreased cake layer permeability and decreased sludge degradation.","Anaerobic digestion; AnDMBR; Flocculant; Membrane fouling reducer; Viscosity","en","journal article","","","","","","","","","","","Sanitary Engineering","","",""
"uuid:76fc37fb-a33e-4c17-a48f-01bbaac72377","http://resolver.tudelft.nl/uuid:76fc37fb-a33e-4c17-a48f-01bbaac72377","Hydrate slurry as cold energy storage and distribution medium: Enhancing the performance of refrigeration systems","Zhou, H. (TU Delft Engineering Thermodynamics)","Vlugt, T.J.H. (promotor); Infante Ferreira, C.A. (copromotor); Delft University of Technology (degree granting institution)","2017","The research presented in this thesis focuses on the use of hydrate slurries in the air conditioning and refrigeration areas. Both experimental and mathematical methods have been used. Hydrate slurries have been suggested as promising cold storage materials that can be used in air conditioning systems due to their high latent heat (193 kJ/kg and 387 kJ/kg for the hydrates studied in this thesis) and positive phase change temperature (12.5 °C and 8.0 °C for the hydrates studied in this thesis). However, large scale industrial applications of hydrate slurries are still very limited. This suggests that more research efforts should be devoted to the demonstration of its advantages.","Hydrate slurry; Air conditioning; Growth model; Energy efficiency","en","doctoral thesis","","978-94-6299-595-6","","","","","","","","","Engineering Thermodynamics","","",""
"uuid:48239759-6d0c-4aea-a203-a1313270040c","http://resolver.tudelft.nl/uuid:48239759-6d0c-4aea-a203-a1313270040c","Engineering a lipase B from Candida antactica with efficient perhydrolysis performance by eliminating its hydrolase activity","Wang, Xu Ping (South China University of Technology); Zhou, Peng Fei (South China University of Technology); Li, Zhi Gang (South China University of Technology); Yang, Bo (South China University of Technology); Hollmann, F. (TU Delft BT/Biocatalysis); Wang, Yong Hua (South China University of Technology)","","2017","A Ser105Ala mutant of the lipase B from Candida antarctica enables 'perhydrolase-only' reactions. At the example of the chemoenzymatic Baeyer-Villiger oxidation of cyclohexanone, we demonstrate that with this mutant selective oxidation can be achieved in deep eutectic solvent while essentially eliminating the undesired hydrolysis reaction of the product.","","en","journal article","","","","","","","","","","","BT/Biocatalysis","","",""
"uuid:c8ac51cf-26b8-4a8f-a48d-dbe419e9f7aa","http://resolver.tudelft.nl/uuid:c8ac51cf-26b8-4a8f-a48d-dbe419e9f7aa","Deep Eutectic Solvents Enable More Robust Chemoenzymatic Epoxidation Reactions","Zhou, Pengfei (South China University of Technology); Wang, Xuping (South China University of Technology); Zeng, Chaoxi (South China University of Technology); Wang, Weifei (South China University of Technology); Yang, Bo (South China University of Technology); Hollmann, F. (TU Delft BT/Biocatalysis); Wang, Yonghua (South China University of Technology)","","2017","A chemoenzymatic method for the production of epoxidized vegetable oils was developed. The unique combination of the commercial lipase G from Penicillieum camembertii with certain deep eutectic solvents enabled the efficient production of epoxidized vegetable oils.","chemoenzymatic synthesis; deep eutectic solvents; enzymes; epoxidation; fatty acids","en","journal article","","","","","","Accepted Author Manuscript","","2017-12-25","","","BT/Biocatalysis","","",""
"uuid:e6062c8a-d04c-4e16-a3ec-a2a1eea9ee3a","http://resolver.tudelft.nl/uuid:e6062c8a-d04c-4e16-a3ec-a2a1eea9ee3a","Assessment of Water Use in Pan-Eurasian and African Continents by ETMonitor with Multi-Source Satellite Data","Zheng, Chaolei (Chinese Academy of Sciences); Jia, L. (TU Delft Optical and Laser Remote Sensing; Chinese Academy of Sciences); Hu, Guangcheng (Chinese Academy of Sciences); Menenti, M. (TU Delft Optical and Laser Remote Sensing; Chinese Academy of Sciences); Lu, Jing (Chinese Academy of Sciences); Zhou, J. (TU Delft Optical and Laser Remote Sensing; Chinese Academy of Sciences); Wang, Kun (Chinese Academy of Sciences); Li, Zhansheng (Chinese Academy of Sciences)","","2017","The Pan-Eurasian and African Continents are characterized by large ranges of climates varying from humid, semi-humid, semi-arid and arid regions, and great challenges exist in water allocation for different sectors that related to water resource and food security, which depends strongly on the water use information. Quantitative information on water use is also important to understand the effectiveness of water allocation and further to prevent from water stress resulted by drought in water-scarce regions. Explosive development of satellite remote sensing observations provide great chance to provide useful spatiotemporal information for quantifying the water use at regional to global scales. In this paper, a process-based model ETMonitor was used in combination with biophysical and hydrological parameters retrieved from earth observations to estimate the actual evapotranspiration, i.e. the agricultural and ecological water use. The total water use is also partitioned into beneficial part, e.g. plant transpiration, and non-beneficial part, e.g. soil evaporation and canopy rainfall interception, according to the water accounting framework. The estimated water use show good agreements with the ground observation, indicating the ability of ETMonitor for global and continental scale water use estimation. The spatial and temporal patterns of the water use in the Pan-Eurasian and African Continents were further analysed, while large spatial variation of water use was convinced. Current study also highlights the great capability of satellite observations in studying the regional water resource and continental water cycle.","","en","journal article","","","","","","","","","","","Optical and Laser Remote Sensing","","",""
"uuid:2eb508c7-0cdb-44e9-b317-7040187744a9","http://resolver.tudelft.nl/uuid:2eb508c7-0cdb-44e9-b317-7040187744a9","Physical simulation method for the investigation of weld seam formation during the extrusion of aluminum alloys","Fang, G (Tsinghua University; State Key Laboratory of Tribology); Nguyen, D.T. (Tsinghua University); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2017","Extrusion through the porthole die is a predominant forming process used in the production of hollow aluminum alloy profiles across the aluminum extrusion industry. Longitudinal weld seams formed during the process may negatively influence the quality of extruded profiles. It is therefore of great importance to understand the formation of weld seams inside the welding chamber during extrusion, as affected by extrusion process variables and die design. Previously developed physical simulation methods could not fully reproduce the thermomechanical conditions inside the welding chamber of porthole die. In this research, a novel physical simulation method for the investigation of weld seam formation during extrusion was developed. With a tailor-designed tooling set mounted on a universal testing machine, the effects of temperature, speed, and strain on the weld seam quality of the 6063 alloy were investigated. The strains inside the welding chamber were found to be of paramount importance for the bonding of metal streams, accompanied by microstructural changes, i.e., recovery or recrystallization, depending on the local deformation condition. The method was shown to be able to provide guidelines for the design of porthole dies and choice of extrusion process variables, thereby reducing the scrap rate of aluminum extrusion operation.","","en","journal article","","","","","","Accepted Author Manuscript","","2017-12-28","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:636d9647-2229-4aa9-b246-0bba3c335dde","http://resolver.tudelft.nl/uuid:636d9647-2229-4aa9-b246-0bba3c335dde","Effect of type-III Anti-Freeze Proteins (AFPs) on CO2 hydrate formation rate","Zhou, H. (TU Delft Engineering Thermodynamics); Infante Ferreira, C.A. (TU Delft Engineering Thermodynamics)","","2017","CO2 hydrate slurry is a favourable direct coolant of fresh products due to its large latent heat and phase change temperature around 7 °C. Continuous production of this slurry is, however, difficult to realise due to the high rate of hydrate formation. The use of additives is proposed with the purpose of decreasing the formation rate so that the controllability of the process is improved. Type-III Antifreeze Proteins (AFPs) are non-poisonous additives which, at low dosage, have proven to be efficient limiters of gas hydrate formation. The effect of these additives on the CO2 hydrate formation rate is experimentally investigated in this study.
The concentration of the AFPs investigated in this research is 10 ppm. Experimental results show that the supercooling degree of the solution is only slightly affected by the addition of AFPs. Results also show that the addition of AFPs slows down the dissolution rate of CO2 gas into the aqueous solution which is the first step of gas hydrate formation. A hydrate growth equation has been used, from which the experimental mass transfer coefficient of CO2 through the solution has been derived. Results show that the decrease of hydrate growth rate with the addition of AFPs can be related to a decrease of the CO2 mass transfer coefficient which gives a lower mass transport rate from bulk liquid phase to the crystal interface.","CO2 hydrate; Anti-Freeze Proteins (AFPs); Growth rate; Mass transfer","en","journal article","","","","","","Accepted Author Manuscript","","2019-04-05","","","Engineering Thermodynamics","","",""
"uuid:2b495b3e-99e8-402b-95cf-b32a6e0b0e53","http://resolver.tudelft.nl/uuid:2b495b3e-99e8-402b-95cf-b32a6e0b0e53","Advanced bredigite-containing magnesium-matrix composites for biodegradable bone implant applications","Naddaf Dezfuli, S. (TU Delft (OLD) MSE-1; TU Delft Biomaterials & Tissue Biomechanics); Huan, Z. (Chinese Academy of Sciences); Mol, J.M.C. (TU Delft (OLD) MSE-6); Leeflang, M.A. (TU Delft Biomaterials & Tissue Biomechanics); Chang, Jiang (Chinese Academy of Sciences); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2017","The present research was aimed at developing magnesium-matrix composites that could allow effective control over their physiochemical and mechanical responses when in contact with physiological solutions. A biodegradable, bioactive ceramic - bredigite was chosen as the reinforcing phase in the composites, based on the hypothesis that the silicon- and magnesium-containing ceramic could protect magnesium from fast corrosion and at the same time stimulate cell proliferation. Methods to prepare composites with integrated microstructures - a prerequisite to achieve controlled biodegradation were developed. A systematic experimental approach was taken in order to elucidate the in vitro biodegradation mechanisms and kinetics of the composites. It was found that the composites with 20–40% homogenously dispersed bredigite particles, prepared from powders, could indeed significantly decrease the degradation rate of magnesium by up to 24 times. Slow degradation of the composites resulted in the retention of the mechanical integrity of the composites within the strength range of cortical bone after 12 days of immersion in a cell culture medium. Cell attachment, cytotoxicity and bioactivity tests confirmed the stimulatory effects of bredigite embedded in the composites on the attachment, viability and differentiation of bone marrow stromal cells. Thus, the multiple benefits of adding bredigite to magnesium in enhancing degradation behavior, mechanical properties, biocompatibility and bioactivity were obtained. The results from this research showed the excellent potential of the bredigite-containing composites for bone implant applications, thus warranting further in vitro and in vivo research.","Bioactivity; Bredigite; Composites; Degradation; Magnesium; Mechanical properties","en","journal article","","","","","","Accepted Author Manuscript","","2019-05-19","","","(OLD) MSE-1","","",""
"uuid:6c3ef35c-7e0c-4962-b342-39be4bc45555","http://resolver.tudelft.nl/uuid:6c3ef35c-7e0c-4962-b342-39be4bc45555","Nonlinear adaptive flight control using incremental approximate dynamic programming and output feedback","Zhou, Y. (TU Delft Control & Simulation); van Kampen, E. (TU Delft Control & Simulation); Chu, Q. P. (TU Delft Control & Simulation)","","2017","","","en","contribution to periodical","","","","","","harvest AIAA 2016-0360","","2018-07-01","","","Control & Simulation","","",""
"uuid:436a9d60-2cb1-4d2e-a6d1-6b592fcb5faf","http://resolver.tudelft.nl/uuid:436a9d60-2cb1-4d2e-a6d1-6b592fcb5faf","Analysis of the bonding strength and microstructure of AA6082 extrusion weld seams formed during physical simulation","Bai, Sheng Wen (Tsinghua University; State Key Lab of Tribology); Fang, Gang (Tsinghua University; State Key Lab of Tribology); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2017","The research was aimed to determine the effects of extrusion process condition on the weld seam quality of the aluminum alloy AA6082 by using a novel physical simulation method. A weld seam between two bars was formed under hydrostatic pressure in a specially designed die setup to simulate the longitudinal weld seam formation during extrusion through porthole die. With this die setup, extrusion process variables, i.e., temperature, extrusion speed and strain, could be varied so that their individual effects on weld seam quality could be discriminated. With the help of finite element (FE) simulation, the distributions of strains, strain rates and hydrostatic pressures inside the welding chamber were quantified. Tension tests were performed to evaluate the bonding strengths of solid-state welded samples. It was found that the amount of deformation imposed inside the welding chamber had a dominant effect on the bonding strength. A high deformation temperature and a high extrusion speed enhanced the bonding strength. The microstructures across the weld zone were examined by using a polarized light microscope and electron back-scatter diffraction (EBSD). The microstructure evolutions inside and around the welding zone were found to be influenced by the deformation condition. High temperature, high extrusion speed and large deformation promoted the occurrence of local dynamic recrystallization, leading to reduced mean grain sizes inside the welding zone, corresponding to an enhanced strength at the weld seam.","Aluminum alloy; Extrusion; Microstructure; Recrystallization; Solid-state welding; Weld seam","en","journal article","","","","","","","","2019-07-18","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:99aa9a04-95bc-4fd4-8582-1e4891b9dffa","http://resolver.tudelft.nl/uuid:99aa9a04-95bc-4fd4-8582-1e4891b9dffa","Application of physical and numerical simulations for interpretation of peripheral coarse grain structure during hot extrusion of AA7020 aluminum alloy","Eivani, A.R. (Iran University of Science and Technology); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2017","In this research, hot compression test is used to simulate the metallurgical phenomena occurring in the peripheral part of AA7020 aluminum alloy extrudates during hot extrusion and leading to the formation of the peripheral coarse grain (PCG) structure. The temperature profiles at a tracking point in the peripheral part of extrudates are predicted using finite element method (FEM). A special thermal treatment representing the predicted thermal profiles during extrusion is designed and applied to specimens after hot-compression testing. The effects of deformation conditions, i.e., temperature and strain rate, and the subsequent special thermal treatment on the formation of coarse grains in the AA7020 alloy are investigated. The as-deformed microstructures of specimens as well as the microstructures of specimens after the special thermal treatment are examined and the average grain size and homogeneity of grain size distribution determined. It is observed that with increasing deformation temperature or decreasing strain rate, the average recrystallized grain size increases. A fine and homogenous grain structure is obtained by increasing strain rate. According to the results of this investigation, formation of coarse grains at the periphery of the extrudate is attributed to high temperatures raised during extrusion rather than high strain rates.","Hot compression; Numerical simulation; Peripheral coarse grain; Physical simulation; Recrystallization","en","journal article","","","","","","Accepted Author Manuscript","","2019-07-18","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:f86df022-9f57-4b31-91ba-c1561cac9f1a","http://resolver.tudelft.nl/uuid:f86df022-9f57-4b31-91ba-c1561cac9f1a","Adaptive path following for Unmanned Aerial Vehicles in time-varying unknown wind environments","Zhou, Bingyu (Student TU Delft); Satyavada, Harish (GE Global Reseach); Baldi, S. (TU Delft Team Bart De Schutter)","Sun, J. (editor); Rajamani, R. (editor)","2017","In this paper, an adaptive control scheme for Unmanned Aerial Vehicles (UAVs) path following under slowly time-varying wind is developed. The proposed control strategy integrates the path following law based on the vector field method with an adaptive term counteracting the effect of wind's unknown component. In particular, it is shown that the path following error is bounded under slowly time-varying unknown wind and converges to zero for unknown constant wind. Numerical simulations illustrate that, in environments with unknown and slowly time-varying wind conditions, the proposed method compensates for the lack of knowledge of the wind vector, and attains a smaller path following error than state-of-the-art vector field method.","","en","conference paper","IEEE","","","","","Accepted Author Manuscript","","","","","Team Bart De Schutter","","",""
"uuid:6087254d-1d16-4136-8cc9-f66b2367f368","http://resolver.tudelft.nl/uuid:6087254d-1d16-4136-8cc9-f66b2367f368","Improvement of mechanical properties of AA6063 aluminum alloy after equal channel angular pressing by applying a two-stage solution treatment","Ashrafizadeh, S.M. (Iran University of Science and Technology); Eivani, A.R. (Iran University of Science and Technology); Jafarian, H.R. (Iran University of Science and Technology); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2017","A two-stage solution treatment composed of an initial soaking at 420 °C for 10 min and the second soaking at 500 °C for 10 min was applied to cold-worked AA6063 aluminum alloy samples after equal channel angular pressing (ECAP) for two and four passes. The microstructures and mechanical properties of the samples were compared with those of the samples after a routine one-stage solution treatment at 500 °C for 10 min. Abnormal grain growth (AGG) occurred to the samples during the one-stage solution treatment. However, no AGG was observed in the samples after the two-stage solution treatment. As a result of the prevention of AGG from occurring, the hardness, yield strength and ultimate tensile strength of the alloy after the two-stage solution treatment were significantly increased, while elongation to failure remained almost unchanged.","Aluminum; Equal channel angular pressing; Grain growth; Heat treatment; Mechanical property","en","journal article","","","","","","Accepted Author Manuscript","","2019-01-07","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:8405475a-3ea1-498f-9d63-6b1d2a089ab5","http://resolver.tudelft.nl/uuid:8405475a-3ea1-498f-9d63-6b1d2a089ab5","Modeling nonlinear moisture diffusion in inhomogeneous media","Chen, Liangbiao (Lamar University); Zhou, Jiang (Lamar University); Chu, Hsing-wei (Lamar University); Zhang, Kouchi (TU Delft Electronic Components, Technology and Materials); Fan, Xuejun (Lamar University)","","2017","While moisture diffusion in microelectronic device and packaging has been studied for decades, the problems involving complex nonlinear moisture diffusion in multi-material assembly have not been fully studied. This paper has developed a general nonlinear diffusion model by adopting water activity, a continuous state variable, as the field variable. The generalized solubility is introduced, which is temperature- and water activity-dependent. The effective diffusivity is defined and derived in terms of generalized solubility and water activity. By comparing the water activity-based model with the existing various normalized models, the present theory can unify and generalize the current approaches. More importantly, the present model can solve both linear and nonlinear moisture diffusion in inhomogeneous material system without normalization. The commercial finite element software has been applied to solve the nonlinear generalized moisture diffusion problem using the analogy of water activity and temperature. A source code of user-defined subroutines in ABAQUS has been provided in the Appendix of the paper. The mathematical formulation and the numerical implementation method presented in this paper can be applied to any nonlinear sorption or diffusion problems in inhomogeneous material system.","Electronic packaging; Microelectronics; Moisture diffusion; Multi-material systems; Nonlinear sorption isotherm; Water activity","en","journal article","","","","","","Accepted author manuscript","","2019-08-10","","","Electronic Components, Technology and Materials","","",""
"uuid:00dbde19-b58d-4741-9735-8d01c718ec16","http://resolver.tudelft.nl/uuid:00dbde19-b58d-4741-9735-8d01c718ec16","Adaptive spacecraft attitude control with incremental approximate dynamic programming","Zhou, Y. (TU Delft Control & Simulation); van Kampen, E. (TU Delft Control & Simulation); Chu, Q. P. (TU Delft Control & Simulation)","","2017","This paper presents an adaptive control technique to deal with spacecraft attitude tracking and disturbance rejection problems in the presence of model uncertainties. Approximate dynamic programming has been proposed to solve adaptive, optimal control problems without using accurate systems models. Within this category, linear approximate dynamic programming systematically utilizes a quadratic cost-to-go function and simplifies the design process. Although modelfree and efficient, linear approximate dynamic programming methods are difficult to apply to nonlinear systems or timevarying systems, such as attitude control of spacecraft disturbed by internal liquid sloshing. To deal with this problem, this paper develops a model-free nonlinear self-learning attitude control method based on incremental Approximate Dynamic Programming to enhance the performance of the spacecraft attitude control system. This method combines the advantages of linear approximate dynamic programming and the incremental nonlinear control techniques, and generates a model-free controller for unknown, time-varying dynamical systems. In this paper, two reference tracking algorithms are developed for off-line learning and online learning, respectively. These algorithms are applied to the attitude control of a spacecraft disturbed by internal liquid sloshing. The results demonstrate that the proposed method deals with the unknown, timevarying internal dynamics adaptively while retaining accurate and efficient attitude control.","Adaptive control; Approximate dynamic programming; Fuel sloshing; Incremental techniques; Nonlinear control","en","conference paper","International Astronautical Federation, IAF","","","","","","","2021-03-22","","","Control & Simulation","","",""
"uuid:4fcb3f12-7bc6-4950-b72a-841d3cd7a609","http://resolver.tudelft.nl/uuid:4fcb3f12-7bc6-4950-b72a-841d3cd7a609","Mesoporous bioactive glass functionalized 3D Ti-6Al-4V scaffolds with improved surface bioactivity","Ye, Xiaotong (Chinese Academy of Sciences); Leeflang, M.A. (TU Delft Biomaterials & Tissue Biomechanics); Wu, Chengtie (Chinese Academy of Sciences); Chang, Jiang (Chinese Academy of Sciences); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Huan, Z. (Chinese Academy of Sciences)","","2017","Porous Ti-6Al-4V scaffolds fabricated by means of selective laser melting (SLM),
having controllable geometrical features and preferable mechanical properties, have been developed as a class of biomaterials that hold promising potential for bone repair. However, the inherent bio-inertness of the Ti-6Al-4V alloy as the matrix of the scaffolds results in a lack in the ability to stimulate bone ingrowth and regeneration. The aim of the present study was to develop a bioactive
coating on the struts of SLM Ti-6Al-4V scaffolds in order to add the desired surface osteogenesis ability. Mesoporous bioactive glasses (MBGs) coating was applied on the strut surfaces of the SLM Ti-6Al-4V scaffolds through spin coating, followed by a heat treatment. It was found that the coating could maintain the characteristic mesoporous structure and chemical composition of
MBG, and establish good interfacial adhesion to the Ti-6Al-4V substrate. The compressive strength and pore interconnectivity of the scaffolds were not affected by the coating. Moreover, the results obtained from in vitro cell culture experiments demonstrated that the attachment, proliferation, and differentiation of human bone marrow stromal cells (hBMSCs) on the MBG-coated Ti-6Al-4V
scaffolds were improved as compared with those on the conventional bioactive glass (BG)-coated Ti-6Al-4V scaffolds and bare-metal Ti-6Al-4V scaffolds. Our results demonstrated that the MBG coating by using the spinning coating method could be an effective approach to achieving enhanced surface biofunctionalization for SLM Ti-6Al-4V scaffolds.","selective laser melting; titanium; scaffold; mesoporous bioactive glass; spin coating; in vitro bioactivity; OA-Fund TU Delft","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:5eacfb85-efdf-43f6-a862-8661b54c6cc7","http://resolver.tudelft.nl/uuid:5eacfb85-efdf-43f6-a862-8661b54c6cc7","An efficient consolidation model for morphodynamic simulations in low SPM-environments","Winterwerp, J.C. (TU Delft Environmental Fluid Mechanics; Deltares); Zhou, Zeng (Hohai University); Battista, Guilia (Deltares); van Kessel, Thijs (Deltares); Jagers, Bert (Deltares); van Maren, D.S. (Deltares); van der Wegen, Mick (IHE Delft Institute for Water Education)","","2017","This paper presents a fast consolidation model suitable for long-term morphodynamic simulations. This model is applicable for muddy systems where sedimentation rates are smaller than consolidation rates, assuming quasi-equilibrium of the consolidating bed. It compares to the consolidation model developed by Sanford (2008). However, in that model, a heuristic, exponential density profile was used. Instead, the current model is derived from the full consolidation (Gibson) equation. The model’s material parameters (hydraulic conductivity, consolidation coefficient and strength) can therefore be derived from soil mechanical experiments in the laboratory.
2, MgCO3 and Ca-free Mg/P inorganics and Ca/P inorganics. In vitro cytotoxicity assay revealed different behaviors of Human Umbilical Vein Endothelial Cells (HUVECs) and Human Aorta Vascular Smooth Muscle Cells (VSMCs) to material extracts. HUVECs showed increasing nitric oxide (NO) release and tolerable toxicity, whereas VSMCs exhibited limited decreasing viability with time. Platelet adhesion, hemolysis and coagulation tests of these Mg-Li-Zn alloys showed different degrees of activation behavior, in which the hemolysis of the Mg-3.5Li-2Zn alloy was lower than 5%. These results indicated the potential of the Mg-Li-Zn alloys as good candidate materials for cardiovascular stent applications. Statement of significance: Mg-Li alloys are promising as absorbable metallic biomaterials, which however have not received significant attention since the low strength, controversial corrosion performance and the doubts in Li toxicity. The Mg-Li-Zn alloy in the present study revealed much improved mechanical properties higher than most reported binary Mg-Li and ternary Mg-Li-X alloys, with superior corrosion resistance in cell culture media. Surprisingly, the addition of Li and Zn showed increased nitric oxide release. The present study indicates good potential of Mg-Li-Zn alloy as absorbable cardiovascular stent material.","Biodegradable metals; Corrosion; Cytocompatibility; Hemocompatibility; Mg-Li-Zn alloy","en","journal article","","","","","","Accepted Author Manuscript","","2019-09-26","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:b5e6e3ed-a25e-4072-b732-98d7cd17b258","http://resolver.tudelft.nl/uuid:b5e6e3ed-a25e-4072-b732-98d7cd17b258","Additively manufactured biodegradable porous magnesium","Li, Y. (TU Delft Biomaterials & Tissue Biomechanics); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Pavanram, P. (Medizinische Fakultat und Universitats Klinikum Aachen); Leeflang, M.A. (TU Delft Biomaterials & Tissue Biomechanics); Fockaert, L.I. (TU Delft (OLD) MSE-6); Pouran, B. (TU Delft Biomaterials & Tissue Biomechanics; University Medical Center Utrecht); Tümer, N. (TU Delft Biomaterials & Tissue Biomechanics); Schröder, K. U. (Institut für Maschinengestaltung und Maschinenelemente); Mol, J.M.C. (TU Delft (OLD) MSE-6); Weinans, Harrie (TU Delft Biomaterials & Tissue Biomechanics; University Medical Center Utrecht); Jahr, H. (Medizinische Fakultat und Universitats Klinikum Aachen; Maastricht UMC); Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)","","2017","An ideal bone substituting material should be bone-mimicking in terms of mechanical properties, present a precisely controlled and fully interconnected porous structure, and degrade in the human body to allow for full regeneration of large bony defects. However, simultaneously satisfying all these three requirements has so far been highly challenging. Here we present topologically ordered porous magnesium (WE43) scaffolds based on the diamond unit cell that were fabricated by selective laser melting (SLM) and satisfy all the requirements. We studied the in vitro biodegradation behavior (up to 4 weeks), mechanical properties and biocompatibility of the developed scaffolds. The mechanical properties of the AM porous WE43 (E = 700-800 MPa) scaffolds were found to fall into the range of the values reported for trabecular bone even after 4 weeks of biodegradation. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), electrochemical tests and μCT revealed a unique biodegradation mechanism that started with uniform corrosion, followed by localized corrosion, particularly in the center of the scaffolds. Biocompatibility tests performed up to 72 h showed level 0 cytotoxicity (according to ISO 10993-5 and -12), except for one time point (i.e., 24 h). Intimate contact between cells (MG-63) and the scaffolds was also observed in SEM images. The study shows for the first time that AM of porous Mg may provide distinct possibilities to adjust biodegradation profile through topological design and open up unprecedented opportunities to develop multifunctional bone substituting materials that mimic bone properties and enable full regeneration of critical-size load-bearing bony defects. Statement of Significance: The ideal biomaterials for bone tissue regeneration should be bone-mimicking in terms of mechanical properties, present a fully interconnected porous structure, and exhibit a specific biodegradation behavior to enable full regeneration of bony defects. Recent advances in additive manufacturing have resulted in biomaterials that satisfy the first two requirements but simultaneously satisfying the third requirement has proven challenging so far. Here we present additively manufactured porous magnesium structures that have the potential to satisfy all above-mentioned requirements. Even after 4 weeks of biodegradation, the mechanical properties of the porous structures were found to be within those reported for native bone. Moreover, our comprehensive electrochemical, mechanical, topological, and biological study revealed a unique biodegradation behavior and the limited cytotoxicity of the developed biomaterials.","Additive manufacturing; Biocompatibility; Biodegradation; Magnesium scaffolds; Mechanical property; Selective laser melting","en","journal article","","","","","","Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.","","2018-06-12","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:8d7d22ad-1c63-462f-af51-bafbd99dea33","http://resolver.tudelft.nl/uuid:8d7d22ad-1c63-462f-af51-bafbd99dea33","Neutron imaging and tomography with MCPS","Duarte Pinto, S.C. (Photonis Technologies S.A.S.); Ortega, R (Photonis Technologies S.A.S.); Ritzau, S. (Photonis Technologies S.A.S.); Pasquale, D (Photonis Technologies S.A.S.); Laprade, B. (Photonis Technologies S.A.S.); Mrotek, S. (Photonis Technologies S.A.S.); Gardell, S. (Photonis Technologies S.A.S.); Zhou, Z. (TU Delft RST/Neutron and Positron Methods in Materials); Plomp, J. (TU Delft RST/Neutron and Positron Methods in Materials); van Eijck, L. (TU Delft RST/Neutron and Positron Methods in Materials); Bilheux, H. (Oak Ridge National Laboratory); Dhiman, I. (Oak Ridge National Laboratory)","","2017","A neutron imaging detector based on neutron-sensitive microchannel plates (mcps) was constructed and tested at beamlines of thermal and cold neutrons. The mcps are made of a glass mixture containing 10B and natural Gd, which makes the bulk of the mcp an efficient neutron converter. Contrary to the neutron-sensitive scintillator screens normally used in neutron imaging, spatial resolution is not traded off with detection efficiency. While the best neutron imaging scintillators have a detection efficiency around a percent, a detection efficiency of around 50% for thermal neutrons and 70% for cold neutrons has been demonstrated with these mcps earlier. Our tests show a performance similar to conventional neutron imaging detectors, apart from the orders of magnitude better sensitivity. We demonstrate a spatial resolution better than 150 Um. The sensitivity of this detector allows fast tomography and neutron video recording, and will make smaller reactor sites and even portable sources suitable for neutron imaging.","Electron multipliers (vacuum); Neutron detectors (cold, thermal, fast neutrons); Neutron radiography; Vacuum-based detectors","en","conference paper","","","","","","","","","","","RST/Neutron and Positron Methods in Materials","","",""
"uuid:5bb743ea-2396-4bef-8975-7b191d82b8fd","http://resolver.tudelft.nl/uuid:5bb743ea-2396-4bef-8975-7b191d82b8fd","Numerical evaluation of induction heating assisted compaction technology for low temperature asphalt pavement construction","Zhou, C. (TU Delft Pavement Engineering); Liu, X. (TU Delft Pavement Engineering); Apostolidis, P. (TU Delft Pavement Engineering)","","2017","Low Temperature Asphalt (LTA) technologies are utilized in asphalt pavement industry to lower energy demands and greenhouse gas emission during mixing and construction processes. Although these technologies are currently available and hope to demonstrate similar performance with Hot Mix Asphalt (HMA) mixes, LTA shows more sensitive than HMA to temperature reduction during compaction and that will lead to inadequate compaction. Especially for Low Temperature Porous Asphalt (LTPA) mixes, the quick reduction of mix temperature is the main cause to poor pavements performance. The induction heating assisted compaction process appears to be an effective way to ameliorate compaction issues and to improve the compactability at lower temperatures. To design this process for LTA mixes, a numerical approach of combining the finite and the discrete element methods is presented in this paper. Porous asphalt concrete was the selected study material. The simulation process was divided into three steps: (i) temperature field prediction during induction heating, (ii) adjustment of asphalt mortar parameters and (iii) asphalt pavement compaction analysis. The effect of induction heating to asphalt compaction effectiveness, the tendency of mix density changing along with the increase of compactor passes and the influence of temperature on compaction at different locations in pavement were studied and discussed as well","Low temperature asphalt; Induction heating; Compaction; Porous asphalt; DEM; FEM","en","conference paper","Transportation Research Board (TRB)","","","","","","","","","","Pavement Engineering","","",""
"uuid:46544734-d063-4b49-9e07-869b8ed46d01","http://resolver.tudelft.nl/uuid:46544734-d063-4b49-9e07-869b8ed46d01","Airborne LiDAR data filtering based on geodesic transformations of mathematical morphology","Li, Y. (TU Delft OLD Department of GIS Technology; Hohai University); Yong, Bin (Hohai University); van Oosterom, P.J.M. (TU Delft OLD Department of GIS Technology); Lemmens, M.J.P.M. (TU Delft OLD Department of GIS Technology); Wu, Huayi (Wuhan University; Collaborative Innovation Center of Geospatial Technology); Ren, Liliang (Hohai University); Zheng, Mingxue (Collaborative Innovation Center of Geospatial Technology; Wuhan University); Zhou, Jiajun (Hohai University)","","2017","The capability of acquiring accurate and dense three-dimensional geospatial information that covers large survey areas rapidly enables airborne light detection and ranging (LiDAR) has become a powerful technology in numerous fields of geospatial applications and analysis. LiDAR data filtering is the first and essential step for digital elevation model generation, land cover classification, and object reconstruction. The morphological filtering approaches have the advantages of simple concepts and easy implementation, which are able to filter non-ground points effectively. However, the filtering quality of morphological approaches is sensitive to the structuring elements that are the key factors for the filtering success of mathematical operations. Aiming to deal with the dependence on the selection of structuring elements, this paper proposes a novel filter of LiDAR point clouds based on geodesic transformations of mathematical morphology. In comparison to traditional morphological transformations, the geodesic transformations only use the elementary structuring element and converge after a finite number of iterations. Therefore, this algorithm makes it unnecessary to select different window sizes or determine the maximum window size, which can enhance the robustness and automation for unknown environments. Experimental results indicate that the new filtering method has promising and competitive performance for diverse landscapes, which can effectively preserve terrain details and filter non-ground points in various complicated environments","LiDAR; filtering; mathematical morphology; geodesic transformation; OA-Fund TU Delft","en","journal article","","","","","","","","","","","OLD Department of GIS Technology","","",""
"uuid:8c410997-4075-44a1-83fb-ac32560b4d22","http://resolver.tudelft.nl/uuid:8c410997-4075-44a1-83fb-ac32560b4d22","Additively manufactured scaffolds for bone tissue engineering and the prediction of their mechanical behavior: A review","Zhang, X.Y. (Tsinghua University); Fang, G (Tsinghua University; State Key Laboratory of Tribology); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics)","","2017","Additive manufacturing (AM), nowadays commonly known as 3D printing, is a revolutionary materials processing technology, particularly suitable for the production of low-volume parts with high shape complexities and often with multiple functions. As such, it holds great promise for the fabrication of patient-specific implants. In recent years, remarkable progress has been made in implementing AM in the bio-fabrication field. This paper presents an overview on the state-of-the-art AM technology for bone tissue engineering (BTE) scaffolds, with a particular focus on the AM scaffolds made of metallic biomaterials. It starts with a brief description of architecture design strategies to meet the biological and mechanical property requirements of scaffolds. Then, it summarizes the working principles, advantages and limitations of each of AM methods suitable for creating porous structures and manufacturing scaffolds from powdered materials. It elaborates on the finite-element (FE) analysis applied to predict the mechanical behavior of AM scaffolds, as well as the effect of the architectural design of porous structure on its mechanical properties. The review ends up with the authors’ view on the current challenges and further research directions.","additive manufacturing; scaffold; biomaterial; geometric design; mechanical property; finite element modeling; OA-Fund TU Delft","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:a472564f-492d-4094-8de3-fdf53a84d095","http://resolver.tudelft.nl/uuid:a472564f-492d-4094-8de3-fdf53a84d095","Chemoenzymatic epoxidation of alkenes with Candida antarctica lipase B and hydrogen peroxide in deep eutectic solvents","Zhou, Pengfei (South China University of Technology); Wang, Xuping (South China University of Technology); Yang, Bo (South China University of Technology); Hollmann, F. (TU Delft BT/Biocatalysis); Wang, Yonghua (South China University of Technology)","","2017","Epoxides are important synthetic intermediates for the synthesis of a broad range of industrial products. This study presents a promising solution to the current limitation of enzyme instability. By using simple deep eutectic solvents such as choline chloride/sorbitol, significant stabilization of the biocatalyst has been achieved leading to more robust reactions while using environmentally more acceptable solvents as compared to ionic liquids.","","en","journal article","","","","","","","","","","","BT/Biocatalysis","","",""
"uuid:760a68ec-7737-42c2-af54-596c1d5bf5bd","http://resolver.tudelft.nl/uuid:760a68ec-7737-42c2-af54-596c1d5bf5bd","In vitro degradation and surface bioactivity of iron-matrix composites containing silicate-based bioceramic","Wang, S. (Chinese Academy of Sciences; Shanghai Institute of Technology); Xu, Y. (Shanghai Jiao Tong University); Zhou, J. (TU Delft Biomaterials & Tissue Biomechanics); Li, H. (Shanghai Jiao Tong University); Chang, Jiang (Chinese Academy of Sciences); Huan, Z. (Chinese Academy of Sciences)","","2017","Iron-matrix composites with calcium silicate (CS) bioceramic as the reinforcing phase were fabricated through powder metallurgy processes. The microstructures, mechanical properties, apatite deposition and biodegradation behavior of the Fe-CS composites, as well as cell attachment and proliferation on
their surfaces, were characterized. In the range of CS weight percentages selected in this study, the composites possessed compact structures and showed differently decreased bending strengths as compared with pure iron. Immersion tests in simulated body fluid (SBF) revealed substantially enhanced deposition of CaP on the surfaces of the composites as well as enhanced degradation rates as compared with pure iron. In addition, the composite containing 20% CS showed a superior ability to stimulate hBMSCs proliferation when compared to pure iron. Our results suggest that incorporating calcium silicate particles into iron could be an effective approach to developing iron-based biodegradable bone implants with improved biomedical performance.","","en","journal article","","","","","","","","","","","Biomaterials & Tissue Biomechanics","","",""
"uuid:1cbd8845-dd4c-40a7-b893-72c4e0a6f21f","http://resolver.tudelft.nl/uuid:1cbd8845-dd4c-40a7-b893-72c4e0a6f21f","Regional surface soil heat flux estimate from multiple remote sensing data in a temperate and semiarid basin","Li, Nana (Chinese Academy of Sciences; Tsinghua University; Joint Center for Global Change Studies); Jia, Li (Chinese Academy of Sciences; Joint Center for Global Change Studies); Lu, Jing (Chinese Academy of Sciences; Joint Center for Global Change Studies); Menenti, M. (TU Delft Optical and Laser Remote Sensing; Chinese Academy of Sciences); Zhou, J. (TU Delft Optical and Laser Remote Sensing)","","2017","The regional surface soil heat flux (G0) estimation is very important for the large-scale land surface process modeling. However, most of the regional G0 estimation methods are based on the empirical relationship between G0 and the net radiation flux. A physical model based on harmonic analysis was improved (referred to as ""HM model"") and applied over the Heihe River Basin northwest China with multiple remote sensing data, e.g., FY-2C, AMSR-E, and MODIS, and soil map data. The sensitivity analysis of the model was studied as well. The results show that the improved model describes the variation of G0 well. Land surface temperature (LST) and thermal inertia (Γ) are the two key input variables to the HM model. Compared with in situ G0, there are some differences, mainly due to the differences between remote-sensed LST and the in situ LST. The sensitivity analysis shows that the errors from-7 to-0.5K in LST amplitude and from-300 to 300J m-2 K-1 s-0.5 in Γ will cause about 20% errors, which are acceptable for G0 estimation.","arid and semiarid area; Harmonic analysis model; regional soil heat flux; remote sensing data; thermal inertia","en","journal article","","","","","","","","","","","Optical and Laser Remote Sensing","","",""
"uuid:1796eb34-d924-48d8-93b8-3958a223cb99","http://resolver.tudelft.nl/uuid:1796eb34-d924-48d8-93b8-3958a223cb99","Deep eutectic solvents as performance additives in biphasic reactions","Lan, Dongming (South China University of Technology); Wang, Xuping (Guangdong Academy of Agricultural Sciences); Zhou, Pengfei (Guangdong Academy of Agricultural Sciences); Hollmann, F. (TU Delft BT/Biocatalysis); Wang, Yonghua (South China University of Technology)","","2017","Deep eutectic solvents act as surfactants in biphasic (hydrophobic/aqueous) reaction mixtures enabling higher interfacial surface areas at lower mechanical stress as compared to simple emulsions. Exploiting this effect the rate of a chemoenzymatic epoxidation reaction was increased more than six-fold.","","en","journal article","","","","","","","","","","","BT/Biocatalysis","","",""
"uuid:76878988-c401-4262-bc56-35282c95e298","http://resolver.tudelft.nl/uuid:76878988-c401-4262-bc56-35282c95e298","Free multi-floor indoor space extraction from complex 3D building models","Xiong, Qing (Wuhan University); Zhu, Qing (Southwest Jiaotong University; Wuhan University; Collaborative Innovation Center for Geospatial Technology); Du, Zhiqiang (Wuhan University; Collaborative Innovation Center for Geospatial Technology); Zlatanova, S. (TU Delft Urban Data Science); Zhang, Yeting (Wuhan University; Collaborative Innovation Center for Geospatial Technology); Zhou, Yan (University of Electric Science and Technology of China, Chengdu); Li, Yun (Southwest Jiaotong University)","","2016","Intelligent navigation and facility management in complex indoor environments are issues at the forefront of geospatial information science. Indoor spaces with fine geometric and semantic descriptions provide a solid foundation for various indoor applications, but it is difficult to comprehensively extract free multi-floor indoor spaces from complex three-dimensional building models, such as those described using CityGML LoD4, with existing methods for the subdivision or extraction of indoor spaces based on vector topology processing. Therefore, this paper elaborates a new voxelbased approach for extracting free multi-floor indoor spaces from 3D building models. It transforms the complicated vector processing tasks into a simple raster process that consists of three steps: voxelization with semantic enhancement, voxel classification, and boundary extraction. Experiments illustrate that the proposed method can automatically and correctly extract free multi-floor indoor spaces, especially two typical kinds of open indoor spaces, namely, lobbies and staircases.","Free multi-floor indoor space; CityGML LoD4; Indoor space extraction; Voxel","en","journal article","","","","","","Accepted Author Manuscript","","2017-11-25","","","Urban Data Science","","",""
"uuid:72891061-1a7c-4259-af45-72078352dc05","http://resolver.tudelft.nl/uuid:72891061-1a7c-4259-af45-72078352dc05","Moving Human path tracking based on video surveillance in 3D indoor scenarious","Zhou, Yan (University of Electric Science and Technology of China, Chengdu); Zlatanova, S. (TU Delft Urban Data Science); Wang, Zhe (University of Electric Science and Technology of China, Chengdu); Zhang, Yeting (Wuhan University); Liu, L. (TU Delft Urban Data Science)","","2016","Video surveillance systems are increasingly used for a variety of 3D indoor applications. We can analyse human behaviour, discover and avoid crowded areas, monitor human traffic and so forth. In this paper we concentrate on use of surveillance cameras to track and reconstruct the path a person has followed. For the purpose we integrated video surveillance data with a 3D indoor model of the building and develop a single human moving path tracking method. We process the surveillance videos to detected single human moving traces; then we match the depth information of 3D scenes to the constructed 3D indoor network model and define the human traces in the 3D indoor space. Finally, the single human traces extracted from multiple cameras are connected with the help of the connectivity provided by the 3D network model. Using this approach, we can reconstruct the entire walking path. The provided experiments with a single person have verified the effectiveness and robustness of the method","Moving Object Tracking; Video Surveillance; 3D Indoor Scenario","en","journal article","","","","","","","","","","","Urban Data Science","","",""
"uuid:72b9197e-28b4-4c3d-9fef-ec56df16da1b","http://resolver.tudelft.nl/uuid:72b9197e-28b4-4c3d-9fef-ec56df16da1b","The structure of (nuclear) graphite: From the atomic to the macro scales","Zhou, Z.","Pappas, C. (promotor)","2016","","nuclear graphite; X-ray diffraction; neutron diffraction; neutron irradiation; small angle neutron scattering; spin echo small angle neutron scattering; neutron imaging","en","doctoral thesis","","","","","","","","","Applied Sciences","RST/Radiation, Science and Technology","","","",""
"uuid:71e714e4-f67c-4c21-a7ab-d19b93c0ff46","http://resolver.tudelft.nl/uuid:71e714e4-f67c-4c21-a7ab-d19b93c0ff46","Enhanced Optical Performance of BaMgAl10O17: Eu2+ Phosphor by a Novel Method of Carbon Coating","Yin, L.J. (TU Delft ChemE/Product and Process Engineering; University of Electronic Science and Technology of China); Dong, Juntao (University of Electronic Science and Technology of China); Wang, Yinping (University of Electronic Science and Technology of China); Zhang, Bi (University of Science and Technology of China); Zhou, Zheng Yang (Peking University); Jian, Xian (University of Electronic Science and Technology of China); Wu, Mengqiang (University of Electronic Science and Technology of China); Xu, Xin (University of Science and Technology of China); van Ommen, J.R. (TU Delft ChemE/Product and Process Engineering); Hintzen, H.T.J.M. (TU Delft RST/Fundamental Aspects of Materials and Energy)","","2016","Many strategies have been adopted to improve thermal degradation of phosphors. Because of the stability and high transmittance of graphene, here we report a novel method of carbon coating on BaMgAl10O17:Eu2+ (BAM) phosphor particles through chemical vapor deposition. The chemical composition, microstructure, and luminescence performance of carbon-coated BAM were characterized carefully. This coating can be controlled within 3-10 atomic layers, depending on the reaction time. Because of the decrease of surface defects and the effective weakening effect of oxidizing Eu2+ to Eu3+ after carbon coating, different layer numbers showed an obvious effect on the optical properties of carbon-coated BAM. Carbon-coated BAM phosphors had higher emission intensity and better oxidation resistance at high temperature than uncoated BAM phosphors. These results indicate that the method of carbon coating on phosphor particles is a promising way to improve the luminescence properties of other phosphors used in lighting and display devices.","","en","journal article","","","","","","Accepted Author Manuscript","","2017-01-08","","","ChemE/Product and Process Engineering","","",""
"uuid:d9e3f248-06fb-48d6-a767-8589ec4b6091","http://resolver.tudelft.nl/uuid:d9e3f248-06fb-48d6-a767-8589ec4b6091","Development and Extension of An Aggregated Scale Model: Part 1 – Background to ASMITA","Townend, I (University of Southampton); Wang, Zhengbing (TU Delft Coastal Engineering); Stive, M.J.F. (TU Delft Coastal Engineering); Zhou, Z. (Hohai University)","","2016","Whilst much attention has been given to models that describe wave, tide and sediment transport processes in sufficient detail to determine the local changes in bed level over a relatively detailed representation of the bathymetry, far less attention has been given to models that consider the problem at a much larger scale (e.g. that of geomorphological elements such as a tidal flat and tidal channel). Such aggregated or lumped models tend not to represent the processes in detail but rather capture the behaviour at the scale of interest. One such model developed using the concept of an equilibrium concentration is the Aggregated Scale Morphological Interaction between Tidal basin and Adjacent coast (ASMITA). In this paper we provide some new insights into the concepts of equilibrium, and horizontal and vertical exchange that are key components of this modelling approach. In a companion paper, we summarise a range of developments that have been undertaken to extend the original model concept, to illustrate the flexibility and power of the conceptual framework. However, adding detail progressively moves the model in the direction of the more detailed process-based models and we give some consideration to the boundary between the two. Highlights
• The concept of aggregating model scales is explored and the basis of the ASMITA model is outlined in detail;
• The relationship between dispersion as used in fast-scale process-based models and the horizontal exchange used in aggregated models is explored;
• The basis for formulating suitable equilibrium relationships is explained; • Alternative ways to include advection and dispersion are examined.
3Al5O12: Ce3+ phosphor powder deposited using atomic layer deposition in a fluidized bed reactor","Zhou, Z. (Hunan Agricultural University); Zhou, Nan (Hunan Agricultural University); Lu, Xiangyang (Hunan Agricultural University); ten Kate, O.M. (TU Delft ChemE/Product and Process Engineering); Valdesueiro Gonzalez, D. (TU Delft ChemE/Product and Process Engineering); van Ommen, J.R. (TU Delft ChemE/Product and Process Engineering); Hintzen, H.T.J.M. (TU Delft RST/Fundamental Aspects of Materials and Energy)","","2016","To improve the thermal stability, Al2O3 has been successfully coated on a Y3Al5O12:Ce3+ (YAG:Ce) phosphor powder host by using the Atomic Layer Deposition (ALD) approach in a fluidized bed reactor. Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray spectroscopy (EDX) analysis indicate that coating an Al2O3 thin layer by ALD is highly feasible. The luminescence properties (such as excitation and emission as well as quantum efficiency and UV-absorption of the coated YAG:Ce phosphor) were systematically analysed, with the further examination of the thermal resistance characteristics. The Al2O3 thin layer coating with precisely controlled thickness by ALD can obviously improve the luminescence intensity and greatly enhances the thermal stability of the YAG:Ce phosphor. It is suggested that the alumina coating with tailoring thickness seems not only to act like a barrier to decrease the thermal quenching, but also as a great help to promote the light absorption and transfer.","","en","journal article","","","","","","Accepted Author Manuscript","","2017-08-08","","","ChemE/Product and Process Engineering","","",""
"uuid:927678db-9839-492e-97a2-55821ff9828d","http://resolver.tudelft.nl/uuid:927678db-9839-492e-97a2-55821ff9828d","Improved ADRC for a Maglev planar motor with a concentric winding structure","Kou, Baoquan (Harbin Institute of Technology); Xing, Feng (Harbin Institute of Technology); Zhang, Chaoning; Zhang, L. (TU Delft Pattern Recognition and Bioinformatics; School of Electrical Engineering and Automation; Harbin Institute of Technology); Zhou, Yiheng (Harbin Institute of Technology); Wang, Tiecheng (Harbin Institute of Technology)","","2016","In the semiconductor industry, positioning accuracy and acceleration are critical parameters. To improve the acceleration speed of a motor, this paper proposes the moving-coil maglev planar motor with a concentric winding structure. The coordinate system has been built for the multiple degrees of freedom movement system. The Lorenz force method has been applied to solve its electromagnetic model. The real-time solving of the generalized inverse matrix of factors can realize the decoupling of the winding current. When the maglev height changes, the electromagnetic force and torque decreases exponentially with the increase of the air gap. To decrease the influence on control system performance by the internal model change and the external disturbance, this paper proposes an improved active disturbance rejection control (ADRC) to design the controller. This new controller overcomes the jitter phenomenon due to the turning point for the traditional ADRC, thus it is more suitable for the maglev control system. The comparison between ADRC and the improved ADRC has been conducted, the result of which shows the improved ADRC has greater robustness.","Concentric winding; Improved ADRC; Maglev planar motor; Robustness","en","journal article","","","","","","","","","","","Pattern Recognition and Bioinformatics","","",""
"uuid:dc6e2971-2d99-4741-89de-892a2687f242","http://resolver.tudelft.nl/uuid:dc6e2971-2d99-4741-89de-892a2687f242","Is “Morphodynamic Equilibrium” an oxymoron?","Zhou, Zeng; Coco, Giovanni; Townend, IH; Olabarrieta, Maitane; van der Wegen, M.; Gong, Zheng; D’Alpaos, Andrea; Gao, Shu; Jaffe, Bruce; Gelfenbaum, Guy; He, Qing; Wang, Yaping; Lanzoni, Stefano; Wang, Zhengbing (TU Delft Coastal Engineering); Winterwerp, J.C. (TU Delft Environmental Fluid Mechanics); Zhang, Changkuan","","2016","Morphodynamic equilibrium is a widely adopted yet elusive concept in the field of geomorphology of coasts, rivers and estuaries. Based on the Exner equation, an expression of mass conservation of sediment, we distinguish three types of equilibrium defined as static and dynamic, of which two different types exist. Other expressions such as statistical and quasi-equilibrium which do not strictly satisfy the Exner conditions are also acknowledged for their practical use. The choice of a temporal scale is imperative to analyse the type of equilibrium. We discuss the difference between morphodynamic equilibrium in the ""real world"" (nature) and the ""virtual world"" (model). Modelling studies rely on simplifications of the real world and lead to understanding of process interactions. A variety of factors affect the use of virtual-world predictions in the real world (e.g., variability in environmental drivers and variability in the setting) so that the concept of morphodynamic equilibrium should be mathematically unequivocal in the virtual world and interpreted over the appropriate spatial and temporal scale in the real world. We draw examples from estuarine settings which are subject to various governing factors which broadly include hydrodynamics, sedimentology and landscape setting. Following the traditional ""tide-wave-river"" ternary diagram, we summarize studies todate that explore the ""virtual world"", discuss the type of equilibrium reached and how it relates to the real world.","","en","journal article","","","","","","","","2019-01-01","","","Coastal Engineering","","",""
"uuid:6f460d8f-c57b-4286-97a7-092aa524bdc6","http://resolver.tudelft.nl/uuid:6f460d8f-c57b-4286-97a7-092aa524bdc6","Investigation of hydrate growth rate on the interface between liquid and solid film","Zhou, H. (TU Delft Engineering Thermodynamics); Infante Ferreira, C.A. (TU Delft Engineering Thermodynamics)","Groll, Eckhard (editor)","2016","Hydrate slurry has been reported to be a suitable secondary fluid for refrigeration and air-conditioning systems. The latent heat of CO2 hydrate is 387 kJ/kg under phase equilibrium condition of 7 °C and 30 bar. The utilization of CO2 hydrate slurry in air-conditioning systems is promising in improving the energy efficiency and shifting energy supply and demand load as well as relieving greenhouse effect caused by normal refrigerants like CFCs, HCFCs etc.
The production of CO2 hydrate slurry in a coil heat exchanger is investigated in this study. Crystals are supposed to firstly form on the wall of the tube, generating a solid layer. The appearance of the solid layer increases the heat resistance from liquid to the refrigerant. Type-III antifreeze proteins have been added to the solution to better control the crystallization process of hydrate formation since AFPs have proven to be an effective hydrate formation preventer which is environment friendly. A kinetic model is developed based on the gas hydrate growth model of Skovborg and Rusmussen (1994), taking the mass transfer process to be the rate-control step. The influence of pressure, temperature and concentration of the hydrate formation preventer on the diffusion coefficient of dissolved gas into the solid interface is investigated and mainly the concentration of hydrate formation preventer appears to have a large impact.
Results show that the growth rate decreases with the increase of the concentration of AFPs. Higher concentrations of AFPs move the equilibrium line to slightly higher temperatures.
0.05 um) decreased. The addition of fly ash increases the volume of gel pores (<0.01 um).","mercury porosimetry; pore size; supplementary cementitious materials","en","conference paper","DCMat Ageing Centre, Delft University of Technology","","","","","","","","Civil Engineering and Geosciences","Structural Engineering","","","",""
"uuid:25897a06-bb52-4adc-b015-a0b6c80ab3d2","http://resolver.tudelft.nl/uuid:25897a06-bb52-4adc-b015-a0b6c80ab3d2","Fabrication of metallic biomedical scaffolds with the space holder method: A review","Arifvianto, B.; Zhou, J.","","2014","Bone tissue engineering has been increasingly studied as an alternative approach to bone defect reconstruction. In this approach, new bone cells are stimulated to grow and heal the defect with the aid of a scaffold that serves as a medium for bone cell formation and growth. Scaffolds made of metallic materials have preferably been chosen for bone tissue engineering applications where load-bearing capacities are required, considering the superior mechanical properties possessed by this type of materials to those of polymeric and ceramic materials. The space holder method has been recognized as one of the viable methods for the fabrication of metallic biomedical scaffolds. In this method, temporary powder particles, namely space holder, are devised as a pore former for scaffolds. In general, the whole scaffold fabrication process with the space holder method can be divided into four main steps: (i) mixing of metal matrix powder and space-holding particles; (ii) compaction of granular materials; (iii) removal of space-holding particles; (iv) sintering of porous scaffold preform. In this review, detailed procedures in each of these steps are presented. Technical challenges encountered during scaffold fabrication with this specific method are addressed. In conclusion, strategies are yet to be developed to address problematic issues raised, such as powder segregation, pore inhomogeneity, distortion of pore sizes and shape, uncontrolled shrinkage and contamination.","tissue engineering; scaffold; space holder method; powder metallurgy; titanium","en","journal article","MDPI","","","","","","","","Mechanical, Maritime and Materials Engineering","Biomechanical Engineering","","","",""
"uuid:aca50001-4e76-4325-b0c4-c585aabdf87f","http://resolver.tudelft.nl/uuid:aca50001-4e76-4325-b0c4-c585aabdf87f","Spectroscopic intravascular photoacoustic imaging of lipids in atherosclerosis","Jansen, K.; Van der Steen, A.F.W.; Wu, M.; Van Beusekom, H.M.M.; Springeling, G.; Li, X.; Zhou, Q.; Shung, K.K.; De Kleijn, D.P.V.; Van Soest, G.","","2014","The natural history of atherosclerosis is marked by changes in the lipid biochemistry in the diseased arterial wall. As lesions become more vulnerable, different cholesterol species accumulate in the plaque. Understanding unstable atherosclerosis as a pharmacological and interventional therapeutic target requires chemically specific imaging of disease foci. In this study, we aim to image atherosclerotic plaque lipids and other vessel wall constituents with spectroscopic intravascular photoacoustics (sIVPA). sIVPA imaging can identify lipids in human coronary atherosclerotic plaque by relying on contrast in the near-infrared absorption spectra of the arterial wall components. Using reference spectra acquired on pure compounds, we analyzed sIVPA data from human coronary plaques ex vivo, to image plaque composition in terms of cholesterol and cholesterol ester content. In addition, we visualized the deeper lying connective tissue layers of the adventitia, as well as the fatty acid containing adipose cells in the peri-adventitial tissue. We performed simultaneous coregistered IVUS imaging to obtain complementary morphological information. Results were corroborated by histopathology. sIVPA imaging can distinguish the most prevalent lipid components of human atherosclerotic plaques and also visualize the connective tissue layers of the adventitia and the fatty acid containing adipose cells in the peri-adventitial tissue.","intravascular imaging; photoacoustic imaging; ultrasonic imaging; spectroscopy; atherosclerosis; lipids","en","journal article","SPIE","","","","","","","","Applied Sciences","ImPhys/Imaging Physics","","","",""
"uuid:06faecb4-6ed4-4a0f-ae9b-e7ba3dc9b5e0","http://resolver.tudelft.nl/uuid:06faecb4-6ed4-4a0f-ae9b-e7ba3dc9b5e0","Evaluation of a Linear Mixing Model to Retrieve Soil and Vegetation Temperatures of Land Targets","Yang, J.; Jia, L.; Cui, Y.; Zhou, J.; Menenti, M.","","2014","A simple linear mixing model of heterogeneous soil-vegetation system and retrieval of component temperatures from directional remote sensing measurements by inverting this model is evaluated in this paper using observations by a thermal camera. The thermal camera was used to obtain multi-angular TIR (Thermal Infra-Red) images over vegetable and orchard canopies. A whole thermal camera image was treated as a pixel of a satellite image to evaluate the model with the two-component system, i.e. soil and vegetation. The evaluation included two parts: evaluation of the linear mixing model and evaluation of the inversion of the model to retrieve component temperatures. For evaluation of the linear mixing model, the RMSE is 0.2 K between the observed and modelled brightness temperatures, which indicates that the linear mixing model works well under most conditions. For evaluation of the model inversion, the RMSE between the model retrieved and the observed vegetation temperatures is 1.6K, correspondingly, the RMSE between the observed and retrieved soil temperatures is 2.0K. According to the evaluation of the sensitivity of retrieved component temperatures on fractional cover, the linear mixing model gives more accurate retrieval accuracies for both soil and vegetation temperatures under intermediate fractional cover conditions.","","en","conference paper","IOP Press","","","","","","","","Civil Engineering and Geosciences","Geoscience & Remote Sensing","","","",""
"uuid:5192ba11-b0c7-4a50-85fc-f0b9054e8481","http://resolver.tudelft.nl/uuid:5192ba11-b0c7-4a50-85fc-f0b9054e8481","Design of a guidance system for waterborne AGVs in accordance with navigation rules (COLREGS)","Zhou, Ningjing","Lodewijks, G. (mentor)","2014","","","","master thesis","","","","","","","","2019-12-01","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Transport Engineering and Logistics","","",""
"uuid:1c20dd35-fbb6-4035-8e05-87e6837dba35","http://resolver.tudelft.nl/uuid:1c20dd35-fbb6-4035-8e05-87e6837dba35","Correlations between reinfall data and insurance damage data related to sewer flooding for the case of Aarhus, Denmark","Spekkers, M.H.; Zhou, Q.; Arnbjerg-Nielsen, K.; Clemens, F.H.L.R.; ten Veldhuis, J.A.E.","","2013","Sewer flooding due to extreme rainfall may result in considerable damage. Damage data to quantify costs of cleaning, drying, and replacing materials and goods are rare in literature. In this study, insurance claim data related to property damages were analysed for the municipality of Aarhus, Denmark. The aim of this paper was to study the extent to which rainfall data can be used to explain variations in insurance claim data. In particular, the paper addresses the issue of time-lag between claim date and time of the damaging rainfall event, which may, if not taken into account, lead to underestimations of correlations between rainfall and damage variables. Rainfall data from two rain gauges were used to extract rainfall characteristics. From cross correlations between time series of rainfall and claim data, it can be concluded that rainfall events induce claims mostly on the same day, but also on the three days after. A linear model that takes into account rainfall data from previous days slightly improves correlations between rainfall and damage variables compared to a simple linear model. Best correlation coefficients were found between maximum hourly rainfall intensity and daily number of claims (0.47-0.57) and daily total damage (0.43-0.53).","sewer flooding; insurance damage data; regression analysis","en","conference paper","Centre of Water Systems","","","","","","","","Civil Engineering and Geosciences","Water Management","","","",""
"uuid:0510a1a1-e730-41e5-ba9c-452ce49b135b","http://resolver.tudelft.nl/uuid:0510a1a1-e730-41e5-ba9c-452ce49b135b","Research on spatial planning and stormwater management of waterfront city: A case study on Dutch city of Almere","Zou, T.; Qu, L.; Zhou, Z.","","2013","","spatial planning; stormwater management; surface water system; land cover type","","journal article","","","","","","","","","Architecture and The Built Environment","Urbanism","","","",""
"uuid:cdd1610e-3e0b-47a9-8410-97a34cabe420","http://resolver.tudelft.nl/uuid:cdd1610e-3e0b-47a9-8410-97a34cabe420","Multi-dimensional indoor location information model","Xiong, Q.; Zhu, Q.; Zlatanova, S.; Huang, L.; Zhou, Y.; Du, Z.","","2013","Aiming at the increasing requirements of seamless indoor and outdoor navigation and location service, a Chinese standard of Multidimensional Indoor Location Information Model is being developed, which defines ontology of indoor location. The model is complementary to 3D concepts like CityGML and IndoorGML. The goal of the model is to provide an exchange GML-based format for location needed for indoor routing and navigation. An elaborated user requirements analysis and investigation of state of-the-art technology in expressing indoor location at home and abroad was completed to identify the manner humans specify location. The ultimate goal is to provide an ontology that will allow absolute and relative specification of location such as “in room 321”, “on the second floor”, as well as, “two meters from the second window”, “12 steps from the door”.","indoor; location model; multi-dimensional; indoor navigation","en","conference paper","ISPRS","","","","","","","","OTB Research Institute for the Built Environment","OTB Research","","","",""
"uuid:1c834e39-1abe-4f73-a81c-26785eeaff49","http://resolver.tudelft.nl/uuid:1c834e39-1abe-4f73-a81c-26785eeaff49","Applying general nonconformity function to transfer AdaBoost algorithm","Zhou, S.; Smirnov, E.N.; Bou Ammar, H.; Peeters, R.","","2013","This paper shows that the region classification task can benefit from instance-transfer learning. It proposes to implement a standard region-classification algorithm using a general nonconformity function based on the Transfer AdaBoost algorithm. The experiments show that the new approach produces valid class regions when instances are transferred from a close domain. The conditions for successful instance transfer are empirically derived.","","en","conference paper","","","","","","","","","","","","","",""
"uuid:aa033d72-7468-44c6-b44d-ff267ab9b17b","http://resolver.tudelft.nl/uuid:aa033d72-7468-44c6-b44d-ff267ab9b17b","Study of Passing Ship Effects along a Bank by Delft3D-FLOW and XBeach","Zhou, M.; Roelvink, J.A.; Verheij, H.J.; Ligteringen, H.","","2013","When a ship sails with a certain speed, there is always a return current along and under the ship. The return current induces a water level depression around the ship. When the ship travels along a bank, the flow field around the ship is asymmetrical. Additional bank effects will be induced. A reliable estimation of all these effects and the resulting behaviour of the passing ship moving along the bank is of great importance to ensure the safe passage of the ship through the restricted waters. The paper presents results of numerical predictions with the open source software Delft3D-FLOW and XBeach of the effects of a ship travelling along a bank. Both models solve the depth averaged non-linear shallow water (NLSW) equations. By applying a moving pressure field method, simulations are carried out for a ship travelling along a sloping bank with a certain speed. Water level fluctuations of the free surface and the depth averaged flow velocities are obtained. The water level fluctuations at three different wave gauges are compared with data from measurements in a physical model. Based on all computations, conclusions are presented about using the moving pressure field method to simulate the passing ship effects sailing along a bank.","passing ship effect; moving pressure field; water level fluctuation; deth-averaged velocity","en","conference paper","","","","","","","","","","","","","",""
"uuid:14abe290-b2d8-4657-bc86-ef16f71e3176","http://resolver.tudelft.nl/uuid:14abe290-b2d8-4657-bc86-ef16f71e3176","Current-induced spin-wave excitation in Pt/YIG bilayer","Zhou, Y.; Jiao, H.; Chen, Y.; Bauer, G.E.W.; Xiao, J.","","2013","We develop a self-consistent theory for current-induced spin-wave excitations in normal metal/magnetic insulator bilayer structures. We compute the spin-wave dispersion and dissipation, including dipolar and exchange interactions in the magnet, the spin diffusion in the normal metal, as well as the surface anisotropy, spin-transfer torque, and spin pumping at the interface. We find that (1) the spin-transfer torque and spin pumping affect the surface modes more than the bulk modes; (2) spin pumping inhibits high-frequency spin-wave modes, thereby redshifting the excitation spectrum; (3) easy-axis surface anisotropy induces a new type of surface spin wave, which reduces the excitation threshold current and greatly enhances the excitation power. We propose that the magnetic insulator surface can be engineered to create spin-wave circuits utilizing surface spin waves as information carriers.","","en","journal article","American Physical Society","","","","","","","","Applied Sciences","QN/Quantum Nanoscience","","","",""
"uuid:3e3d348c-fdc2-4646-8a59-954ad70f7dea","http://resolver.tudelft.nl/uuid:3e3d348c-fdc2-4646-8a59-954ad70f7dea","Groundwater–surface water interactions, vegetation dependencies and implications for water resources management in the semi-arid Hailiutu River catchment, China – a synthesis","Zhou, Y.; Wenninger, J.; Yang, Z.; Yin, L.; Huang, J.; Hou, L.; Wang, X.; Zhang, D.; Uhlenbrook, S.","","2013","During the last decades, large-scale land use changes took place in the Hailiutu River catchment, a semi-arid area in northwest China. These changes had significant impacts on the water resources in the area. Insights into groundwater and surface water interactions and vegetation-water dependencies help to understand these impacts and formulate sustainable water resources management policies. In this study, groundwater and surface water interactions were identified using the baseflow index at the catchment scale, and hydraulic and water temperature methods as well as event hydrograph separation techniques at the sub-catchment scale. The results show that almost 90% of the river discharge consists of groundwater. Vegetation dependencies on groundwater were analysed from the relationship between the Normalized Difference Vegetation Index (NDVI) and groundwater depth at the catchment scale and along an ecohydrogeological cross-section, and by measuring the sap flow of different plants, soil water contents and groundwater levels at different research sites. The results show that all vegetation types, i.e. trees (willow (Salix matsudana) and poplar (Populus simonii), bushes (salix – Salix psammophila), and agricultural crops (maize – Zea mays)), depend largely on groundwater as the source for transpiration. The comparative analysis indicates that maize crops use the largest amount of water, followed by poplar trees, salix bushes, and willow trees. For sustainable water use with the objective of satisfying the water demand for socio-economical development and to prevent desertification and ecological impacts on streams, more water-use-efficient crops such as sorghum, barley or millet should be promoted to reduce the consumptive water use. Willow trees should be used as wind-breaks in croplands and along roads, and drought-resistant and less water-use intensive plants (for instance native bushes) should be used to vegetate sand dunes.","","en","journal article","European Geosciences Union (EGU)","","","","","","","","Civil Engineering and Geosciences","Water Management","","","",""
"uuid:38943d4a-6446-4f43-b41d-27f078e38bb2","http://resolver.tudelft.nl/uuid:38943d4a-6446-4f43-b41d-27f078e38bb2","The effect of processing parameters on the formation of epoxy/UF resin microcapsules","Zhu, G.; Wu, Z.; Zhou, Y.; Tang, J.; Dong, B.; Han, N.; Xing, F.","","2013","Epoxy E-51/UF resin microcapsules were prepared by traditional two-stepped in situ polymerization method and processing parameters affecting the final microcapsules shape and size were carefully studied in the aim to obtain microcapsule with ideally spherical shape and uniform size. Its found the polycarboxylate surfactant of SMA (styrene-maleic anhydride) is better than the monomolecule sulfate surfactant of SDBS (dodecylbenzenesulphonate) in the emulsification of Epoxy E-51, because the microcapsules from epoxy E-51/SMA emulsion possess good sphericity and clear surface. On the second step of reaction, U/F mole ratio should be controlled in 1.5~2:1 region, and ammonium chloride (NH4Cl) or m-dihydroxybenzene are strongly recommended to be added to strengthen the shell. For a higher encapsulation ratio, acidification time should be controlled in 2~3h and the end-point pH value of the curing reaction should be controlled at 2~2.5, respectively. The core/shell ratio (weight) is optimal at 2:1 and reaction temperature at 60-65°C.","microcapsule; epoxy,; urea formaldehyde resin; self-healing","en","conference paper","","","","","","","","","","","","","",""
"uuid:ebf781d1-2ab9-492c-b19d-d927466620df","http://resolver.tudelft.nl/uuid:ebf781d1-2ab9-492c-b19d-d927466620df","The effect of grain size on the mechanical properties and the oxidation induced crack healing efficiency of CR2ALC ceramic","Duan, X.; Jia, D.; Yang, Z.; Zhou, Y.; Ouyang, J.; Sloof, W.G.; Van der Zwaag, S.","","2013","Abstract only.","Cr2AlC ceramic; grain size; mechanical properties; self-healing","en","conference paper","","","","","","","","","","","","","",""
"uuid:8d013847-f09a-449d-8c7a-e818a0458ee5","http://resolver.tudelft.nl/uuid:8d013847-f09a-449d-8c7a-e818a0458ee5","Microstructure evolution of Cr2AlC ceramic before and after oxidation induced crack healing","Rao, J.; Jia, D.; Duan, X.; Yang, Z.; Zhou, Y.; Ouyang, J.; Sloof, W.G.; Van der Zwaag, S.","","2013","Abstract only.","Cr2AlC ceramic; self-healing; SEM; TEM","en","conference paper","","","","","","","","","","","","","",""
"uuid:27cf69fa-bc7a-4737-8992-cae11bb4e5b7","http://resolver.tudelft.nl/uuid:27cf69fa-bc7a-4737-8992-cae11bb4e5b7","Self-healing evolution of oxidized surface of AL4SIC4 and its effect on mechanical properties","Huang, X.; Geng, X.; Wen, G.; Song, G.; Zhou, Y.","","2013","Abstract only.","Al4SiC4; microstructure; self-healing; mechanical testing","en","conference paper","","","","","","","","","","","","","",""
"uuid:b10f335a-5f49-46a4-ada1-ce80ca25e6ee","http://resolver.tudelft.nl/uuid:b10f335a-5f49-46a4-ada1-ce80ca25e6ee","The effect of SiC particle size on the healing efficiency of alumina at high temperatures","Boatemaa, L.; Zhou, J.; Van der Zwaag, S.; Sloof, W.G.","","2013","Structural ceramics like alumina are usually brittle and sensitive to flaws leading to a reduction in their mechanical properties. This situation is worsened by machining prior to service and during service by contact, which introduces micro cracks and hidden damages. Crack damage can easily be developed in such ceramics when loaded, which often leads to catastrophic failure. However, if sacrificial SiC healing particles are embedded into the matrix of alumina, then the cracks can be healed by exposure at high temperatures in an oxidizing environment. Then, the cracks are filled with SiO2 restoring the strength of the composite and thereby prolonging its lifetime. Reducing the size of the SiC healing particles while keeping the volume fraction the same, will increase the efficiency and lowers the onset temperature of the oxidation induced crack healing.","self-healing; Al2O3; SiC; high temperature; oxidation kinetics","en","conference paper","Magnel Laboratory for Concrete Research","","","","","","","","Mechanical, Maritime and Materials Engineering","Materials Science and Engineering","","","",""
"uuid:3e2ea4cb-dd78-4580-ba56-223f04b87c68","http://resolver.tudelft.nl/uuid:3e2ea4cb-dd78-4580-ba56-223f04b87c68","Mechanism for abnormal thermal shock behavior of MAX ceramics","Li, S.; Zhou, Y.","","2013","Abstract only.","MAX ceramics; self-healing; abnormal thermal shock behavior; mechanism","en","conference paper","","","","","","","","","","","","","",""
"uuid:5c3f8f0d-d869-4a11-a5f1-490968a55d03","http://resolver.tudelft.nl/uuid:5c3f8f0d-d869-4a11-a5f1-490968a55d03","The effect of SiC particle size on the healing efficiency of alumina at high temperatures","Boatemaa, L.; Zhou, J.; Van der Zwaag, S.; Sloof, W.G.","","2013","Structural ceramics like alumina are usually brittle and sensitive to flaws leading to a reduction in their mechanical properties. This situation is worsened by machining prior to service and during service by contact, which introduces micro cracks and hidden damages. Crack damage can easily be developed in such ceramics when loaded, which often leads to catastrophic failure. However, if sacrificial SiC healing particles are embedded into the matrix of alumina, then the cracks can be healed by exposure at high temperatures in an oxidizing environment. Then, the cracks are filled with SiO2 restoring the strength of the composite and thereby prolonging its lifetime. Reducing the size of the SiC healing particles while keeping the volume fraction the same, will increase the efficiency and lowers the onset temperature of the oxidation induced crack healing.","self-healing; Al2O3; SiC; high temperature; oxidation kinetics","en","conference paper","","","","","","","","","","","","","",""
"uuid:c26242ce-c011-4655-826d-fd37dbdc4cc0","http://resolver.tudelft.nl/uuid:c26242ce-c011-4655-826d-fd37dbdc4cc0","Self-encapsulation of epoxy resin by a controlled interface curing process in epoxy/water emulsion","Zhu, G.; Zhou, Y.; Wu, Z.; Tang, J.; Dong, B.; Han, N.; Xing, F.","","2013","The microcapsules of epoxy E-51 resin encapsulated by cured itself were prepared by interfacial curing reaction, in which ethylenediamine (EDA) was employed as curing agent and sulfonated copolymer of styrene and maleic anhydride (SMA) as emulsifying agent. Its found the morphology of microcapsules strongly depend on reaction time and EDA dosage. Usually, the microcapsules were formed in 20mins, Extension of the time doesnt change the morphology but thicken the shell and strengthen the microcapsules. Large dose of EDA bring about smooth surface of microcapsules. Its believed that this simple process to fabricate epoxy microcapsules is more suitable for the application of self healing concrete, because it is ease to be industrialized and can be produced in large scale.","microcapsule; epoxy; self-healing; emulsion","en","conference paper","","","","","","","","","","","","","",""
"uuid:5f3afb4e-4a0e-4b23-9677-a97a8b5ff2f7","http://resolver.tudelft.nl/uuid:5f3afb4e-4a0e-4b23-9677-a97a8b5ff2f7","A global evaluation of harmonic analysis of time series under distrinct gap conditions","Zhou, J.; Hu, G.; Menenti, M.","","2013","Reconstruction of time series of satellite image data to obtain continuous, consistent and accurate data for downstream applications is playing a crucial role in remote sensing applications such as vegetation dynamics, land cover changes, land-atmosphere interactions and climate changes. Among the numerous methods and models developed to reconstruct time series of satellite obser-vations in recent decades, Harmonic ANalysis of Time Series (HANTS) is one of the most widely used. Many studies based on time series reconstructed with HANTS documented the excellent performance of this method. In the view of this study, the HANTS algorithm can be divided into two sub-processes, i.e., contam-inated data identification and series reconstruction based on valid data. This study was dedicated to the evaluation of the performance of the latter sub-process. A simulated reference series dataset was constructed first, and then random gaps were introduced to these reference series. We built a look up table for distinct gap conditions by doing statistics on the deviation between the reference series and series reconstructed from gapped reference series. The look up table was used to eval-uate the performance of a global NDVI time series dataset processed by HANTS. The results show that the size of maximum gap (MGS), the number of loss (NL) and the number of gaps (NG) were significant factors in the reconstruction. When NDVI time series were rebuilt by HANTS, most of the region north than 40°N and mountainous areas of earth show bad reconstruc-tion performance, that is, the root mean square deviation (RMSD) could exceed 0.25. This can be attributed to the periodical snow cover in these regions.","","en","journal article","European Association of Remote Sensing Laboratories","","","","","","","","Civil Engineering and Geosciences","Geoscience & Remote Sensing","","","",""
"uuid:a7613cbd-f530-4425-944e-31cdf4da9d7e","http://resolver.tudelft.nl/uuid:a7613cbd-f530-4425-944e-31cdf4da9d7e","Atypical Glycolysis in Clostridium thermocellum","Zhou, J.; Olson, D.G.; Argyros, D.A.; Deng, Y.; Van Gulik, W.M.; Van Dijken, J.P.; Lynd, L.R.","","2013","Cofactor specificities of glycolytic enzymes in Clostridium thermocellum were studied with cellobiose-grown cells from batch cultures. Intracellular glucose was phosphorylated by glucokinase using GTP rather than ATP. Although phosphofructokinase typically uses ATP as a phosphoryl donor, we found only pyrophosphate (PPi)-linked activity. Phosphoglycerate kinase used both GDP and ADP as phosphoryl acceptors. In agreement with the absence of a pyruvate kinase sequence in the C. thermocellum genome, no activity of this enzyme could be detected. Also, the annotated pyruvate phosphate dikinase (ppdk) is not crucial for the generation of pyruvate from phosphoenolpyruvate (PEP), as deletion of the ppdk gene did not substantially change cellobiose fermentation. Instead pyruvate formation is likely to proceed via a malate shunt with GDP-linked PEP carboxykinase, NADH-linked malate dehydrogenase, and NADP-linked malic enzyme. High activities of these enzymes were detected in extracts of cellobiose-grown cells. Our results thus show that GTP is consumed while both GTP and ATP are produced in glycolysis of C. thermocellum. The requirement for PPi in this pathway can be satisfied only to a small extent by biosynthetic reactions, in contrast to what is generally assumed for a PPi-dependent glycolysis in anaerobic heterotrophs. Metabolic network analysis showed that most of the required PPi must be generated via ATP or GTP hydrolysis exclusive of that which happens during biosynthesis. Experimental proof for the necessity of an alternative mechanism of PPi generation was obtained by studying the glycolysis in washed-cell suspensions in which biosynthesis was absent. Under these conditions, cells still fermented cellobiose to ethanol.","","en","journal article","American Society for Microbiology","","","","","","","","Applied Sciences","Biotechnology","","","",""
"uuid:5a87bfaf-322e-4fa2-9e17-8b69d4c4d7c9","http://resolver.tudelft.nl/uuid:5a87bfaf-322e-4fa2-9e17-8b69d4c4d7c9","Field-free synthetic-ferromagnet spin torque oscillator","Zhou, Y.; Xiao, J.; Bauer, G.E.W.; Zhang, F.C.","","2013","We study the magnetization dynamics of spin valve structures with a free composite synthetic ferromagnet (SyF) that consists of two ferromagnetic layers coupled through a normal metal spacer. A ferromagnetically coupled SyF can be excited into dynamical precessional states by an applied current without external magnetic fields. We analytically determine the stability of these states in the space spanned by the current density and SyF interlayer exchange coupling. Numerical simulations confirm our analytical results.","","en","journal article","American Physical Society","","","","","","","","Applied Sciences","QN/Quantum Nanoscience","","","",""
"uuid:96139b14-16f7-4c20-8577-482a7aba7a3c","http://resolver.tudelft.nl/uuid:96139b14-16f7-4c20-8577-482a7aba7a3c","Controlling of merging electric field and IMF magnitude on storm-time changes in thermospheric mass density","Zhou, Y.L.; Ma, S.Y.; Liu, R.S.; Luehr, H.; Doornbos, E.","","2013","The controls of merging electrical field, Em, and IMF (interplanetary magnetic field) magnitude, B, on the storm-time changes in upper thermospheric mass density are statistically investigated using GRACE accelerometer observations and the OMNI data of solar wind and IMF for 35 great storms during 2002–2006. It reveals the following: (1) The correlation coefficients between the air mass density changes and the parameters of Em and B are generally larger at lower latitudes than at higher latitudes, and larger in noon and midnight sectors than in dawn and dusk. (2) The most likely delay time (MLDT) of mass density changes in respect to Em is about 1.5 h (4.5 h) at high (low) latitudes, having no distinct local time dependence, while it is 6 h at middle latitudes in all the local time sectors except for noon, which is longer than at low latitudes. A similar fact of longer delay time at mid-latitude is also seen for B. The MLDTs for B at various latitudes are all local time dependent distinctly with shorter delay time in noon/midnight sector and larger in dawn/dusk. Despite of widely spread of the delay time, IMF B exhibits still larger correlation coefficients with mass density changes among the interplanetary parameters. (3) The linear control factor of B on the density changes increases for large B, in contrast to somewhat saturation trend for larger Em. (4) The influence of B and Em on the mass densities shows different behavior for different types of storms. The influence intensity of Em is much stronger for CIR-driven than for CME-driven storm, while it is not so distinct for B. On the local time asymmetry of the influence, both Em and B have largest influence at noon sector for CME-driven storms, while an obviously larger intensification of the influence is found in dawn/dusk sector during CIR storms, especially for parameter Em.","","en","journal article","European Geosciences Union (EGU)","","","","","","","","Aerospace Engineering","Space Engineering","","","",""
"uuid:e697f391-ccb4-4d71-a0f6-13d2d1177766","http://resolver.tudelft.nl/uuid:e697f391-ccb4-4d71-a0f6-13d2d1177766","Heading control for turret-moored vessel in level ice based on Kalkman filter with thrust allocation","Zhou, Li; Moan, Torgeir; Riska, Kaj; Su, Biao","","2013","","hydrodynamics","","journal article","","","","","","","","","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Hydromechanics and Structures","","",""
"uuid:d0781200-1e73-4b29-a451-219f3adf3a08","http://resolver.tudelft.nl/uuid:d0781200-1e73-4b29-a451-219f3adf3a08","Urban Vitality in Dutch and Chinese New Towns: A comparative study between Almere and Tongzhou","Zhou, J.","Meyer, V.J. (promotor)","2012","Building new towns seems to be a rational approach that releases pressure from overly burdened large cities. This strategy was developed in Western Europe in the middle of twentieth century. Since the 1990s, the European new town model has been widely implemented in China. However, the author questions the feasibility of the large-scale, hasty new town developments. The study of worldwide new town experiences, especially European and Chinese cases, demonstrates that many new towns in fact have difficulty in achieving a real sense of urban quality and vitality. So far, few research projects have been conducted to evaluate and develop solutions for this problem. 'Urban vitality in Dutch and Chinese new towns' identifies the spatial and non-spatial factors and conditions that facilitate the development of urban vitality in new towns. It is aimed to reveal the impacts of spatial design, urban planning and governance approaches on the degree and patterns of local urban life of new towns in China and in the Netherlands, based on a comparative study of two cases: Almere in the north wing of the Randstad region in the Netherlands and Tongzhou in the metropolitan region of Beijing in China. The study does not intend to tackle the economic and sociological concepts in themselves, but to focus on the interrelationships between space and society.","new town; urban planning; urban vitality; Almere; Tongzhou","en","doctoral thesis","TU Delft","","","","","","","","Architecture","Urbanism","","","",""
"uuid:c8a8ea8c-dfd8-48d6-a9b2-f9c03f117619","http://resolver.tudelft.nl/uuid:c8a8ea8c-dfd8-48d6-a9b2-f9c03f117619","Integrated, Ecosystem-based Marine Spatial Planning: First Results from International Simulation-Game Experiment","Mayer, I.S.; Zhou, Q.; Lo, J.; Abspoel, L.; Keijser, X.; Olsen, E.; Nixon, E.; Kannen, A.","","2012","Marine ecosystems around the globe are increasingly affected by human activities such as fisheries, shipping, offshore petroleum developments, wind farms, recreation, tourism and more. Whereas the necessity and urgency to regulate and plan competing marine spatial claims is growing, the planning and regulation of these claims is even more difficult than on land, among others because of insufficient data and knowledge on how ecosystems are affected, the international dimension of marine ecosystems and, as yet, poorly validated Marine Spatial Planning practices. The main question in this paper is: what exactly defines the high level of complexity of Marine Spatial Planning (MSP), and, given the strong transnational dimension of MSP, what can be done to integrate and harmonize the various planning practices of the EU member states? In this paper, the authors present the use of an international simulation-game (with 68 international MSP professionals in Lisbon, 3 November 2011) to conduct an expert panel study on MSP, both in the real and gamed countries. In order to analyze the panel and in-game data, several scales on MSP-outcome and process were defined and validated. In this paper the authors present the main insights of the pre-game panel study. They conclude that the differences in approaches to the MSP process and outcomes among the real countries are significant.","marine spatial planning; marine ecosystems; integrated planning; simulation-game; serious game; modeling; science-policy interface; evaluation","en","conference paper","","","","","","","","","Technology, Policy and Management","Multi Actor Systems","","","",""
"uuid:8f871146-6c21-49db-9b33-f981d852f5e2","http://resolver.tudelft.nl/uuid:8f871146-6c21-49db-9b33-f981d852f5e2","Intravascular ultrasound chirp imaging","Maresca, D.; Jansen, K.; Renaud, G.; Van Soest, G.; Li, X.; Zhou, Q.; De Jong, N.; Shung, K.K.; Van der Steen, A.F.W.","","2012","We demonstrate the feasibility of intravascular ultrasound (IVUS) chirp imaging as well as chirp reversal ultrasound contrast imaging at intravascular ultrasound frequency. Chirp excitations were emitted with a 34?MHz single crystal intravascular transducer and compared to conventional Gaussian-shaped pulses of equal acoustic pressure. The signal to noise ratio of the chirp images was increased by up to 9?dB relative to the conventional images. Imaging of contrast microbubbles was implemented by chirp reversal, achieving a contrast to tissue ratio of 12?dB. The method shows potential for intravascular imaging of structures in and beyond coronary atherosclerotic plaques including vasa vasorum","biomedical transducers; biomedical ultrasonics; blood vessels; chirp modulation; medical disorders; ultrasonic transducers","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","IST/Imaging Science and Technology","","","",""
"uuid:4268a0bb-26c3-464c-a9fe-796ddd5b58ab","http://resolver.tudelft.nl/uuid:4268a0bb-26c3-464c-a9fe-796ddd5b58ab","The causes of flow regime shifts in the semi-arid Hailiutu River, Northwest China","Yang, Z.; Zhou, Y.; Wenninger, J.; Uhlenbrook, S.","","2012","Identifying the causes (climate vs. human Identifying the causes (climate vs. human activities) for hydrological variability is a major challenge in hydrology. This paper examines the flow regime shifts, changes in the climatic variables such as precipitation, evaporation, temperature, and crop area in the semi-arid Hailiutu catchment in the middle section of the Yellow River by performing several statistical analyses. The Pettitt test, cumulative sum charts (CUSUM), regime shift index (RSI) method, and harmonic analysis were carried out on annual, monthly, and daily discharges. Four major shifts in the flow regime have been detected in 1968, 1986, 1992 and 2001. Characteristics of the flow regime were analyzed in the five periods: 1957–1967, 1968–1985, 1986–1991, 1992–2000, and 2001–2007. From 1957 to 1967, the flow regime reflects quasi natural conditions of the high variability and larger amplitude of 6 months periodic fluctuations. The river peak flow was reduced by the construction of two reservoirs in the period 1968–1985. In the period of 1986–1991, the river discharge further decreased due to the combined influence of river diversions and increase of groundwater extractions for irrigation. In the fourth period of 1992–2000, the river discharge reached lowest flow and variation in corresponding to a large increase in crop area. The flow regime recovered, but not yet to natural status in the fifth period of 2001–2007. Climatic factors are found not likely responsible for the changes in the flow regime, but the changes in the flow regime are corresponding well to historical land use policy changes.","","en","journal article","Copernicus, GmbH","","","","","","","","Civil Engineering and Geosciences","Water Management","","","",""
"uuid:e8f7fdb9-d209-45be-9e03-13da46e386bc","http://resolver.tudelft.nl/uuid:e8f7fdb9-d209-45be-9e03-13da46e386bc","Event-based progression detection strategies using scanning laser polarimetry images of the human retina","Vermeer, K.A.; Lo, B.; Zhou, Q.; Vos, F.M.; Vossepoel, A.M.; Lemij, H.G.","","2011","Monitoring glaucoma patients and ensuring optimal treatment requires accurate and precise detection of progression. Many glaucomatous progression detection strategies may be formulated for Scanning Laser Polarimetry (SLP) data of the local nerve fiber thickness. In this paper, several strategies, all based on repeated GDx VCC SLP measurements, are tested to identify the optimal one for clinical use. The parameters of the methods were adapted to yield a set specificity of 97.5% on real image series. For a fixed sensitivity of 90%, the minimally detectable loss was subsequently determined for both localized and diffuse loss. Due to the large size of the required data set, a previously described simulation method was used for assessing the minimally detectable loss. The optimal strategy was identified and was based on two baseline visits and two follow-up visits, requiring two-out-of-four positive tests. Its associated minimally detectable loss was 5–12?m, depending on the reproducibility of the measurements.","progression detection; simulation; glaucoma; polarimetry; optimization; image processing","en","journal article","Elsevier","","","","","","","","Applied Sciences","IST/Imaging Science and Technology","","","",""
"uuid:541de37d-226a-4ece-8dc9-995eb9efd835","http://resolver.tudelft.nl/uuid:541de37d-226a-4ece-8dc9-995eb9efd835","Coupling ground penetrating radar and fluid flow modeling for oilfield monitoring applications","Miorali, M.; Zhou, F.; Slob, E.C.; Arts, R.","","2011","The recent introduction of smart well technology allows for new geophysical monitoring opportunities. Smart wells, which allow zonal production control, combined with monitoring techniques capable of capturing the arrival of undesired fluids, have the potential to significantly increase the oil recovery. We consider borehole radar as a valuable technology for monitoring of the near-well region. By coupling a drainage process of a bottom water-drive reservoir with electromagnetic simulations, we find that radar sensors located in the production well can successfully map the fluid saturation evolution. In low-conductivity reservoirs (<0.02 S/m), a system performance above 80 dB is necessary to record reflections in the range of 10 m. Higher conductivity values strongly reduce the radar investigation depth. Despite the technical challenges to implement a permanent down-hole radar system, the potential semi-continuous acquisition would make 4D ground-penetrating radar a promising technology in capturing the near-well fluid dynamics. Suitable environments are bottom water-drive reservoirs with thin oil layer and heavy oil reservoirs exploited by steam-assisted gravity drainage processes.","geophysical fluid dynamics; ground penetrating radar; oil drilling; well logging","en","journal article","Society of Exploration Geophysicists","","","","","","","","Civil Engineering and Geosciences","Geoscience & Engineering","","","",""
"uuid:d2bd7f60-d754-46c5-8e4f-3953f723bdc1","http://resolver.tudelft.nl/uuid:d2bd7f60-d754-46c5-8e4f-3953f723bdc1","An investigation of link quality assessment for mobile multi-hop and multi-rate wireless networks","Zhou, J.; Jacobsson, M.; Onur, E.; Niemegeers, I.","","2011","Wireless ad hoc networks will be an important component in future communication systems. The performance of wireless ad hoc networks can be improved by link quality-aware applications. Wireless link quality is dynamic in nature, especially in mobile scenarios. Therefore, accurate and fast packet delivery ratio estimation is a prerequisite to good performance inmobile,multi-hop andmulti-rate wireless ad hoc networks. In this paper, we propose a novel packet delivery ratio estimation method that improves the accuracy and responsiveness of the packet delivery ratio estimation. The proposed link quality estimation components are implemented in a IEEE 802.11b/g test-bed. The experiment results show that the accuracy of the packet delivery ratio estimation can improve up to 50% in mobile scenarios without introducing overhead. We also show the end-to-end performance impact of this improved estimation on route selection using different routing metrics and configurations. The measurement results show that our packet delivery ratio method leads to better route selection in the form of increased end-to-end throughput compared to traditional methods, which respond slowly to the link dynamics.","link quality assessment and measurement; mobile, multi-hop, multi-rate wireless networks; link quality aware routing","en","journal article","Springer Verlag","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Telecommunications","","","",""
"uuid:4bc07d00-4455-4c38-b97e-5a06e77d9ce7","http://resolver.tudelft.nl/uuid:4bc07d00-4455-4c38-b97e-5a06e77d9ce7","Performance of Engineered Cementitious Composites for Concrete Repairs","Zhou, J.","Van Breugel, K. (promotor); Ye, G. (promotor)","2011","Background and goals of this thesis The concrete repair, rehabilitation and retrofitting industry grows rapidly, driven by deterioration of, damage to and defects in concrete structures. However, it is well known that to achieve durable concrete repairs is very difficult. The failure of concrete repairs causes high economical, social and environmental impacts. The main reason of failures is that most repair materials and the repair-substrate interface cannot withstand the high stresses induced by differential shrinkage. Failures, therefore, manifest themselves by cracking in the repair material and debonding of the repair material from the substrate. The first goal of this thesis is to develop a “green” Engineered Cementitious Composites (ECC) and to demonstrate the good performance of this “green” ECC. The second goal is to develop a numerical tool, which can simulate the bond strength between the repair material and the concrete substrate, to assist engineers in designing a durable concrete repair with good bond. Research methodology The stresses induced by differential shrinkage in repair systems were investigated analytically. The analytical study has shown that differential shrinkage induces lower stresses in the ECC repair system, compared with conventional repair materials. For this reason, ECC was chosen as a repair material in this research. Conventional ECC contains a larger amount of cement than concrete, typically two or three times larger. The high cement content leads a high shrinkage, high costs and poor sustainability performance. A “green” ECC with low cement content was developed by partially substituting Portland cement with limestone powder and blast furnace slag. The surface cracking and interface delamination of the “green” ECC repair system were investigated experimentally. In order to demonstrate the potential of ECC to prolong the service life of the repair structures, the rapid chloride migration (RCM) test was used to investigate the chloride penetration profile in the cracked ECC repair system. In order to investigate the microstructure development and the bond mechanism in concrete repairs, the experimental techniques, including non-evaporable water test, MIP, ESEM and bond strength test, were applied. In order to quantitatively study the microstructure development and the bond strength in the repair system, the cement hydration model HYMOSTRUC was extended. The moisture transport between the two materials (the repair material and the concrete substrate) and the cement hydration process of the repair material was taken into account in this numerical tool. Summary of the results of this thesis The analytical study has revealed that the shrinkage of the repair material, the size of the repair system, the Young’s modulus and the roughness of the substrate influence the distribution and magnitude of the differential shrinkage-induced stresses. It was also found that differential shrinkage induces lower stresses in the ECC repair system compared with conventional repair materials. This thesis demonstrates the feasibility of designing a “green” ECC with limestone powder and BFS. This mixture has a Portland cement content as low as 15% (by weight), which is about half of the standard ECC. At 28 days, the “green” ECC shows high tensile strain capacity of 3.3% and a moderate compressive strength of 38. Subjected to a differential shrinkage, the “green” ECC repair system shows a larger number of cracks and smaller crack width (40 ?m) than a conventional repair material, e.g. a fiber-reinforced polymer-modified repair mortar. Even though ECC cracks, it can carry more tensile load and accommodate larger tensile strain. Due to the smaller crack width, the maximum chloride penetration depth in ECC is much smaller than that in a conventional repair material. The service life prediction using the DuraCrete model revealed that, in order to achieve the same service life, the ECC repair system needs smaller cover thickness than the conventional repair material. It is also found that the bond strength is a crucial factor influencing the performance of the ECC repair system. To enhance the bond strength, therefore, is very important to realize durable ECC repairs. The moisture transport shows a significant influence on the cement hydration and microstructure development of the repair material. Before setting of the repair material, the concrete substrate absorbs water from the repair material. This causes a reduction of the w/c ratio in the repair material. The reduction of the w/c ratio affects the degree of hydration and the porosity of the repair material as well as the bond strength. After setting of the repair material, the cement hydration works as a “motor” and generates the driving force for the moisture exchange in the two materials, while water acts as “fuel”, which is consumed by the “motor” and influences the efficiency of the “motor”. The numerical study has shown that the microstructure development of the repair material and the bond strength are influenced by many parameters, i.e. the porosity and water content of the concrete substrate, the w/c ratio of the repair material, and the thickness of the repair material and the concrete substrate. The correlation between the bond strength and the microstructure of the repair material was observed numerically. Due to the “wall effect”, the cement particles have a loose packing at the interface, and the w/c ratio locally increases. The increased w/c ratio results in a porous interfacial zone. The tensile strength of the interface is, in case of a smooth surface of the substrate, lower than that of the repair material. As a result, under a tensile load, the specimen with a smooth surface of the substrate fails at the interface. The surface roughness does not influence the moisture exchange and the cement hydration process. However, it has a significant influence on the bond strength. As the surface roughness increases, the contact area between the repair material and the concrete substrate increases as well. The increased contact area contributes to the bonding of the interface. As a result, the bond strength increases, and the failure changes from debonding at the interface to cracking of the repair material. Based on the above fact, ECC, with its high ductility and tight crack width, is a good choice.","concrete repairs; Engineered Cementitious Composites; bond strength","en","doctoral thesis","","","","","","","","","Civil Engineering and Geosciences","Design and Construction","","","",""
"uuid:8f50f369-dcd6-47a1-8628-17299de7ade6","http://resolver.tudelft.nl/uuid:8f50f369-dcd6-47a1-8628-17299de7ade6","Effect of the size distribution of nanoscale dispersed particles on the Zener drag pressure","Eivani, A.R.; Valipour, S.; Ahmed, H.; Zhou, J.; Duszczyk, J.","","2010","In this article, a new relationship for the calculation of the Zener drag pressure is described in which the effect of the size distribution of nanoscale dispersed particles is taken into account, in addition to particle radius and volume fraction, which have been incorporated in the existing relationships. Microstructural observations indicated a clear correlation between the size distribution of dispersed particles and recrystallized grain sizes in the AA7020 aluminum alloy. However, the existing relationship to calculate the Zener drag pressure yielded a negligible difference of 0.016 pct between the two structures homogenized at different conditions resulting in totally different size distributions of nanoscale dispersed particles and, consequently, recrystallized grain sizes. The difference in the Zener drag pressure calculated by the application of the new relationship was 5.1 pct, being in line with the experimental observations of the recrystallized grain sizes. Mathematical investigations showed that the ratio of the Zener drag pressure from the new equation to that from the existing equation is maximized when the number densities of all the particles with different sizes are equal. This finding indicates that in the two structures with identical parameters except the size distribution of nanoscale dispersed particles, the one that possesses a broader size distribution of particles, i.e., the number densities of particles with different sizes being equal, gives rise to a larger Zener drag pressure than that having a narrow size distribution of nanoscale dispersed particles, i.e., most of the particles being in the same size range.","","en","journal article","Springer Verlag","","","","","","","","Mechanical, Maritime and Materials Engineering","Materials Science and Engineering","","","",""
"uuid:83d6e8aa-15e0-4390-8067-e057848a75aa","http://resolver.tudelft.nl/uuid:83d6e8aa-15e0-4390-8067-e057848a75aa","Impact of wireless link quality across communication layers","Zhou, J.","Niemegeers, I. (promotor)","2010","Nowadays, wireless networks are used in most of the applications with radio technologies being used in all kinds of wireless networks. In all wireless links, the transmitted packets can be lost. How to identify the quality of a certain wireless link and achieve the best delivery performance over a certain wireless network is an open issue. In this thesis, the performance of wireless mesh network, wireless sensor network and cellular network have been investigated by the method of measurements, simulations and mathematical model. Several novel algorithms also have been proposed. We have proposed two mechanisms to estimate wireless links where better performance is achieved compared to the traditional algorithms. The achievements lead to a higher end-to-end throughput (faster information delivery) for the IEEE 802.11 networks. Meanwhile, an energy saving and interference reducing mechanism for wireless mesh and sensor networks has been proposed and validated which can dramatically save energy in those wireless networks. Impact of wireless link quality on heterogeneous cellular and ad hoc networks has been evaluated and the results could be used for Telecom operators for the cellular networks optimization. Test-beds for IEEE 802.11 and IEEE 802.15.4 have been built and the 3G cellular networks have been studied via simulations. We looked at the the impact of the wireless link quality to the MAC layer for the IEEE 802.11 and IEEE 802.15.4; the impact of the wireless link quality to the IEEE 802.11 network layer. To understand the link quality characteristics of these two radios, we carried out many measurement experiments with various indoor and outdoor scenarios. The measurement methods and results are presented in Chapter 2. To achieve accurate link quality estimation, we proposed two estimation methods for different scenarios in Chapter 3. In Chapter 4, we used accurate link quality information to determine the packet transmission power level in the IEEE 802.11 and IEEE 802.15.4's MAC layer and the measurement results show that the energy consumption and interference reduces. The accurate link quality estimation methods are further used in data rate adaptation in the IEEE 802.11's MAC layer (Chapter 5) and route selection in the IEEE 802.11's network layer (Chapter 6). The measurements using IEEE 802.11 devices show tremendous performance enhancement. Our algorithms and results can be useful for all kinds of protocol designs for IEEE 802.11 and IEEE 802.15.4 networks. Furthermore, we look at the end-to-end performance of the cellular multihop network which comprises of two different wireless networks, 3G UMTS/HSDPA network and IEEE 802.11 network in Chapter 7. When multiple TCP flows exist in the cellular multi-hop network, different flows may not share the cellular network's resources fairly due to the fact that each flow may have different topology and wireless link quality. We have proposed a weighted scheduling method which obviously alleviates this unfairness. In Chapter 8, a typical video streaming traffic, MPEG-4 is used to evaluate the end-to-end performance over the cellular multi-hop network. The results show that wireless link quality also has great impact on the end-to-end performance of MPEG-4 over the cellular multi-hop network. Our result can be used by the telecom operators to optimize the UMTS/HSDPA system for the cellular multi-hop scenario. We conclude our thesis and suggest the future research directions in Chapter 9.","wireless communication; link quality estimation; rate adaptation; power saving; link quality based routing; performance evaluation","en","doctoral thesis","IPSKAMP","","","","","","","2010-10-19","Electrical Engineering, Mathematics and Computer Science","Telecommunications","","","",""
"uuid:8fcdd945-b2eb-4e3b-90c2-96835f0ed197","http://resolver.tudelft.nl/uuid:8fcdd945-b2eb-4e3b-90c2-96835f0ed197","Magnesium-based composites with improved in vitro surface biocompatibility","Huan, Z.; Zhou, J.; Duszczyk, J.","","2010","In this study, bioactive glass (BG, 45S5) particles were added to a biodegradable magnesium alloy(ZK30) through a semi-solid high-pressure casting process in order to improve the surface biocompatibility of the biomaterial and potentially its bioactivity. The observation of the as-cast microstructures of ZK30-BG composites indicated homogeneous dispersion of BG particles in the matrix. SEM, EDX and EPMA showed the retention of the morphological characteristics and composition of BG particles in the as-cast composite materials. In vitro tests in a cell culture medium confirmed that the composites indeed possessed an enhanced ability to induce the deposition of a bone-like apatite layer on the surface, indicating an improved surface biocompatibility as compared with the matrix alloy.","","en","journal article","Springer","","","","","","","","Mechanical, Maritime and Materials Engineering","Materials Science and Engineering","","","",""
"uuid:32ae70dd-66e5-4d23-bd43-974c5efbb6c2","http://resolver.tudelft.nl/uuid:32ae70dd-66e5-4d23-bd43-974c5efbb6c2","Link Quality-Based Transmission Power Adaptation for Reduction of Energy Consumption and Interference","Zhou, J.; Jacobsson, M.; Niemegeers, I.","","2010","Today, many wireless devices are mobile and battery powered. Based on the fact that battery capacity is still limited, energy saving is an important issue in wireless communication.Meanwhile, the number of wireless devices continues to increase and this creates interference problems between wireless devices. In this paper, we look at transmission power control and propose a mechanism that tries to achieve minimum energy consumption or emission under any circumstance. Lower transmission power levels may result in more retransmissions, but in total, energy consumption or emission still can be reduced in many scenarios. To evaluate the performance of our mechanism, we used real wireless channels in an indoor environment to carry out measurements. The measurement results indicate that a significant amount of energy consumption or emission reduction can be achieved for the transmitter in most scenarios compared to using a fixed transmission power level for all packets.","","en","journal article","Hindawi Publishing Corporation","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Telecommunications","","","",""
"uuid:2f216666-16cd-4662-816c-f95ccf543876","http://resolver.tudelft.nl/uuid:2f216666-16cd-4662-816c-f95ccf543876","Gaming as the method to integrate modeling participatory approaches in interactive water management","Zhou, Q.; Mayer, I.S.","","2010","At the science - policy interface there are several reasons to combine models with the participatory process to facilitate the complex policy making process but the communication of the two sides is often too hard to generate any meaningful results. In this paper we argue that to close the communication gap the rationale of the Meta – rule of complex policy making needs to be comprehended and coped with. Gaming as a participatory method can be used to organize the combined process. Through the literature review we summarize the principles of gaming and use them to analyze an empirical case where stakeholders participated in a water policy making process. A computer model called the Planning Kit Blokkendoos (PKB, in English: Box of Blocks) was used here to support the participatory process and is claimed to have had a marked impact on the complex policy making process. We conclude that the PKB tool provided the stakeholders with significant ‘room to play’ with the various policy alternatives and interweaved with the policy process.","science-policy interface; interactive water management; Planning Kit; Blokkendoos; stakeholder participation; simulation-gaming","en","conference paper","International Environmental Modelling and Software Society (iEMSs)","","","","","","","","Technology, Policy and Management","Multi Actor Systems","","","",""
"uuid:8c913198-d9f8-4891-a0a2-9cff0f7cd00e","http://resolver.tudelft.nl/uuid:8c913198-d9f8-4891-a0a2-9cff0f7cd00e","In vitro degradation behavior and cytocompatibility of Mg–Zn–Zr alloys","Huan, Z.G.; Leeflang, M.A.; Zhou, J.; Fratila-Apachitei, L.E.; Duszczyk, J.","","2010","Zinc and zirconium were selected as the alloying elements in biodegradable magnesium alloys, considering their strengthening effect and good biocompatibility. The degradation rate, hydrogen evolution, ion release, surface layer and in vitro cytotoxicity of two Mg–Zn–Zr alloys, i.e. ZK30 and ZK60, and a WE-type alloy (Mg–Y–RE–Zr) were investigated by means of longterm static immersion testing in Hank’s solution, non-static immersion testing in Hank’s solution and cell-material interaction analysis. It was found that, among these three magnesium alloys, ZK30 had the lowest degradation rate and the least hydrogen evolution. A magnesium calcium phosphate layer was formed on the surface of ZK30 sample during non-static immersion and its degradation caused minute changes in the ion concentrations and pH value of Hank’s solution. In addition, the ZK30 alloy showed insignificant cytotoxicity against bone marrow stromal cells as compared with biocompatible hydroxyapatite (HA) and the WE-type alloy. After prolonged incubation for 7 days, a stimulatory effect on cell proliferation was observed. The results of the present study suggested that ZK30 could be a promising material for biodegradable orthopedic implants and worth further investigation to evaluate its in vitro and in vivo degradation behavior.","","en","journal article","Springer","","","","","","","","Mechanical, Maritime and Materials Engineering","Materials Science and Engineering","","","",""
"uuid:48b14b97-0bfc-4a4f-a503-7cf489dbe500","http://resolver.tudelft.nl/uuid:48b14b97-0bfc-4a4f-a503-7cf489dbe500","Engineered cementitious composites with low volume of cementitious materials","Zhou, J.; Quian, S.; Van Breugel, K.","","2010","Engineered cementitious composite (ECC) is an ultra ductile cement-based material reinforced with fibers. It is characterized by high tensile ductility and tight crack width control. Thanks to the excellent performance, ECC is emerging in broad applications to enhance the loading capacity and the durability of structures. However, ECC also faces a limitation on dimensional stability and on economical and sustainable issues. In general, a large amount of cementitious materials, often more than 70% by weight, is used in ECC and no coarse aggregate is allowed to be added. The high volume of cementitious materials in ECC results in a large drying shrinkage and negative effects on material cost and material greenness. In this paper, a new version of ECC is designed with low volume of cementitious materials about 25% by weight, including Portland cement, blast furnace slag and silica fume, and a large amount of filler and aggregate, including limestone powder and river sand. In this mix, only 1.2% of fibers by volume is mixed, which is 60% dosage of standard ECC. Experimental study reveals that the newly developed ECC shows tensile ductility of 2% and relatively low shrinkage. Considering the low cementitious material and fiber contents, the newly developed ECC might have a reduced cost and increased material greenness.","","en","conference paper","","","","","","","","","Civil Engineering and Geosciences","Structural Engineering","","","",""
"uuid:982672e7-ddec-4e98-b22f-21cbbf6d5444","http://resolver.tudelft.nl/uuid:982672e7-ddec-4e98-b22f-21cbbf6d5444","Relating tensile properties with flexural properties in SHCC","Qian, S.; Li, V.C.; Zhou, J.","","2010","Strain hardening cementitious composites (SHCCs) have seen increasing field applications in past decade, yet existing quality control test methods for tensile properties are sometime difficult to implement. This paper presents a new simple inverse method for quality control of tensile strain capacity by conducting beam flexural test. It is shown through a theoretical model that the beam deflection from a flexural test can be linearly related to tensile strain capacity. A master curve relating this easily measured structural element property to material tensile strain capacity is constructed from parametric studies of a wide range of material tensile and compressive properties. This proposed method (UM method) has been validated with uniaxial tensile test results with reasonable agreement. Good agreement between prediction and tensile test suggest that this method is very robust for different mixtures with variable geometry and test setup.","","en","conference paper","","","","","","","","","Civil Engineering and Geosciences","Structural Engineering","","","",""
"uuid:ba180658-da35-4470-a3ee-c03c48657e40","http://resolver.tudelft.nl/uuid:ba180658-da35-4470-a3ee-c03c48657e40","Flexible labor and innovation performance: Evidence from longitudinal firm-level data","Dekker, R (Ronald.Dekker@tudelft.nl; TU Delft, Technology, Policy and Management, Innovation Systems); Kleinknecht, A.H. (A.H.Kleinknecht@tudelft.nl; TU Delft, Technology, Policy and Management, Innovation Systems); Zhou, H (Erasmus University Rotterdam, Erasmus School of Economics, CASBEC)","","2010","Firms with high shares of workers on fixed-term contracts have significantly higher sales of imitative new products but perform significantly worse on sales of innovative new products (“first on the market”). High functional flexibility in “insider-outsider” labor markets enhances a firm’s new product sales, as do training efforts and highly educated personnel. We find weak evidence that larger and older firms have higher new product sales than do younger and smaller firms. Our findings should be food for thought to economists making unqualified pleas for the deregulation of labor markets.","Innovation performance; new product sales; numerical flexibility; functional flexibility; SMEs; OSA longitudinal data; RePEc","","working paper","","","","","","","","","","","","","",""
"uuid:a1d03601-41da-4895-8046-fc7ed040cc15","http://resolver.tudelft.nl/uuid:a1d03601-41da-4895-8046-fc7ed040cc15","Peripheral Cluster versus New Town: A Comparative Study on Two Types of Peripheral Developments in the Beijing Metropolitan Region","Zhou, J.; Qu, L.","","2009","","","en","journal article","Delft School of Design","","","","","","","","Architecture","Urbanism","","","",""
"uuid:535c0ee5-4d6a-4043-9aee-9b604d4f0d28","http://resolver.tudelft.nl/uuid:535c0ee5-4d6a-4043-9aee-9b604d4f0d28","Low-temperature fabrication of macroporous scaffolds through foaming and hydration of tricalcium silicate paste and their bioactivity","Huan, Z.; Chang, J.; Zhou, J.","","2009","A low-temperature fabrication method for highly porous bioactive scaffolds was developed. The two-step method involved the foaming of tricalcium silicate cement paste and hydration to form calcium silicate hydrate and calcium hydroxide. Scaffolds with a combination of interconnected macro- and micro-sized pores were fabricated by making use of the decomposition of a hydrogen peroxide (H2O2) solution that acted as a foaming agent and through the hydration of tricalcium silicate cement. It was found possible to control the porosity and pore sizes by adjusting the concentration of the H2O2 solution. The in vitro bioactivity of the highly porous scaffolds was investigated by immersion in simulated body fluid (SBF) for 7 days. Hydroxyapatite (HAp) was formed on the surface of the scaffolds. Their bioactivity could be expected to be as good as that of tricalcium silicate cement, making the material competent for the bone tissue engineering application.","","en","journal article","Springer","","","","","","","","Mechanical, Maritime and Materials Engineering","","","","",""
"uuid:1a12b803-4e7c-4640-bc95-ca0fd575cfd6","http://resolver.tudelft.nl/uuid:1a12b803-4e7c-4640-bc95-ca0fd575cfd6","Urbanism PhD Research 2008 - 2010","Van der Hoeven, F.D.; Brand, N.; Van der Burg, L.; Çal??kan, O.; Tan, E.R.; Wang, C.Y.; Zhou, J.","Smit, M. (contributor)","2009","To ensure the quality of the Ph.D. research the Department introduced a special procedure for periodic evaluation: after a period of nine months the potential Ph.D. candidates are asked to present their research design, theoretical framework and methodological approach to the members of the Department and to an external review, drawn up by the professors of the Department and by external reviewer. Depending on the assessment of the review group, the candidates will have the opportunity to continue their research at the Department. In the mean time the (public) review sessions developed into an important element for the scientific debate of the Department. The sessions became a meeting point for the whole Department to discuss new research issues and new methodological approaches and to develop new research collaborations. In this framework the external members of the review group are playing an important role. Their critics form a mirror for the scientific standards of the Department as well as for the scientific (and social) relevancy of the research issues. With the publication of the this book we want to offer to a broader public the opportunity to deal with this debate. The different contributions are based on the papers the Ph.D. candidates prepared for the reviews and have been updatedas a result of the remarks of the peer group and the discussion during the review sessions. As a result the contributions are reflecting the ongoing efforts to redefine the discipline of urbanism under globally changing conditions. The review sessions of the department started in 2004. This book presents the results of the sessions that took place late 2007 and throughout much of 2008.","built environment; cultural heritage; housing; landscape architecture; landscape design; regional planning; spatial planning; town planning; urban design; urban development; urban planning; urban studies; urbanism","en","book","IOS Press","","","","","","","","Architecture","Urbanism","","","",""
"uuid:30e55ed7-81df-42b8-af7d-dc3b5ea606a8","http://resolver.tudelft.nl/uuid:30e55ed7-81df-42b8-af7d-dc3b5ea606a8","Wind power integration: From individual wind turbine to wind park as a power plant","Zhou, Y.","Ferreira, J.A. (promotor); Bauer, P. (promotor)","2009","As power capacities of single wind turbine, single wind park and total wind power installation are continuously increasing, the wind power begins to challenge the safety operation of the power system. This thesis focuses on the grid integration aspects such as the dynamic behaviours of wind power during disturbances, and dynamic behaviours of power system with large wind power integration. The work in this thesis is in a down-up approach, starting with concepts for individual wind turbines, including control and modelling, followed by a conceptual wind park design and control, and finally on the highest level, wind power plant support aimed at improving power system performance.","grid integration; wind power; wind energy; power system","en","doctoral thesis","","","","","","","","2009-10-31","Electrical Engineering, Mathematics and Computer Science","Electrical Power Engineering","","","",""
"uuid:5da401ab-6257-42a2-a5a7-b8fddededab4","http://resolver.tudelft.nl/uuid:5da401ab-6257-42a2-a5a7-b8fddededab4","Development of engineered cementitious composites with limestone powder and blast furnace slag","Zhou, J.; Qian, S.; Sierra Beltran, M.G.; Ye, G.; Van Breugel, K.; Li, V.C.","","2009","Nowadays limestone powder and blast furnace slag (BFS) are widely used in concrete as blended materials in cement. The replacement of Portland cement by limestone powder and BFS can lower the cost and enhance the greenness of concrete, since the production of these two materials needs less energy and causes less CO2 emission than Portland cement. Moreover, the use of limestone powder and BFS improves the properties of fresh and hardened concrete, such as workability and durability. Engineered cementitious composites (ECC) is a class of ultra ductile fiber reinforced cementitious composites, characterized by high ductility, tight crack width control and relatively low fiber content. The limestone powder and BFS are used to produce ECC in this research. The mix proportion is designed experimentally by adjusting the amount of limestone powder and BFS, accompanied by four-point bending test and uniaxial tensile test. This study results in an ECC mix proportion with the Portland cement content as low as 15% of powder by weight. This mixture, at 28 days, exhibits a high tensile strain capacity of 3.3%, a tight crack width of 57 lm and a moderate compressive strength of 38 MPa. In order to promote a wide use of ECC, it was tried to simplify the mixing of ECC with only two matrix materials, i.e. BFS cement and limestone powder, instead of three matrix materials. By replacing Portland cement and BFS in the aforementioned ECC mixture with BFS cement, the ECC with BFS cement and limestone powder exhibits a tensile strain capacity of 3.1%, a crack width of 76 lm and a compressive strength of 40 MPa after 28 days of curing.","engineered cementitious composites; tensile strain capacity; limestone powder; blast furnace slag; blast furnace cement","en","journal article","Springer","","","","","","","","Civil Engineering and Geosciences","Design and Construction","","","",""
"uuid:c02e8257-fc39-4339-9643-3cc40e7fc156","http://resolver.tudelft.nl/uuid:c02e8257-fc39-4339-9643-3cc40e7fc156","Correlation between Electrical Resistivity, Particle Dissolution, Precipitation of Dispersoids, and Recrystallization Behavior of AA7020 Aluminum Alloy","Eivani, A.R.; Ahmed, H.; Zhou, J.; Duszczyk, J.","","2009","This research concerns the effect of homogenization treatment on the electrical resistivity of AA7020 aluminum alloy variants with different Zr and Cr contents. Small changes in the Zr and Cr contents of the as-cast alloy increase the electrical resistivity significantly. After employing various homogenization treatments, the electrical resistivity decreases, which is due to the depletion of Zr, Cr, and Mn in the matrix, by forming small dispersoids. The optimum treatment proposed in order to obtain the smallest recrystallized grains is to hold the material at 550 °C for 24 hours, which results in the lowest electrical resistivity. The viability of the proposed treatment was tested through hot compression tests and static annealing. Indeed, the samples homogenized at 550 °C for 24 hours showed the smallest recrystallized grains compared to those homogenized at other temperatures.","","en","journal article","Springer","","","","","","","","Mechanical, Maritime and Materials Engineering","Materials Science and Engineering","","","",""
"uuid:a9034441-0e30-4142-8acd-0c55757e12ac","http://resolver.tudelft.nl/uuid:a9034441-0e30-4142-8acd-0c55757e12ac","Characteristics of the Friction Between Aluminium and Steel at Elevated Temperatures During Ball-on-Disc Tests","Wang, L.; Cai, J.; Zhou, J.; Duszczyk, J.","","2009","Appropriate specification of the frictional boundary condition for the finite-element (FE) simulation of metal-forming processes is of great importance to the trustworthiness of the results. The research reported in this communication aimed at understanding the interfacial contact between aluminium and steel at elevated temperatures and determining friction coefficients at this material mating. A series of high-temperature ball-on-disc tests were carried out with the AA7475 aluminium alloy as the material of disc and the hardened H11 steel as the material of ball. A mathematical model developed in the preceding research was employed to account for the evolution of the contact interface during ball-on-disc tests. Friction coefficients at different temperatures and over a number of laps were determined. The shear friction stresses and mean contact pressures along with the progress of the tests at 350–500 °C were calculated. It was found that the friction coefficients obtained from ball-on-disc tests alone were insufficient to represent the frictional interaction between deforming aluminium and steel at elevated temperatures. The evolution of the contact interface with increasing sliding distance must be taken into consideration and the friction behaviour can be reasonably characterized by using friction stress.","Ball-on-disc test; FE Simulation; Extrusion; Friction coefficient","en","journal article","Springer","","","","","","","","Mechanical, Maritime and Materials Engineering","Materials Science and Engineering","","","",""
"uuid:8a23ad65-9905-49d7-87b8-fd7dca2eff27","http://resolver.tudelft.nl/uuid:8a23ad65-9905-49d7-87b8-fd7dca2eff27","Flexible labor and innovation performance: Evidence from longitudinal firm-level data","Kleinknecht, A.; Dekker, R.; Zhou, H.","","2009","Firms with high shares of workers on fixed-term contracts have significantly higher sales of imitative new products but perform significantly worse on sales of innovative new products (“first on the market”). High functional flexibility in “insider-outsider” labor markets enhances a firm’s new product sales, as do training efforts and highly educated personnel. We find weak evidence that larger and older firms have higher new product sales than do younger and smaller firms. Our findings should be food for thought to economists making unqualified pleas for the deregulation of labor markets.","Innovation performance; new product sales; numerical flexibility","en","journal article","Delft University of Technology","","","","","","","","Technology, Policy and Management","","","","",""
"uuid:edfaf4ed-63ce-442e-b2ff-5b738a13fa1b","http://resolver.tudelft.nl/uuid:edfaf4ed-63ce-442e-b2ff-5b738a13fa1b","Operation of grid-connected DFIG under unbalanced grid voltage condition","Zhou, Y.; Bauer, P.; Ferreira, J.A.; Pierik, J.","","2009","Doubly fed induction generator (DFIG) still shares a large part in today's wind power market. It provides the benefits of variable speed operation cost-effectively, and can control its active and reactive power independently. Crowbar protection is often adopted to protect the rotor-side voltage source converter (VSC) from transient overcurrent during grid voltage dip. But under unbalanced grid voltage condition, the severe problems are not the transient overcurrent, but the electric torque pulsation and dc voltage ripple in the back-to-back VSCs. This paper develops dynamic models in MATLAB/Simulink, validates it through experiments, investigates the behavior of DFIG during unbalanced grid voltage condition, and proposes new controllers in separated positive and negative sequence. Methods to separate positive and negative sequence components in real time are also developed, and their responses to unsymmetrical voltage dip are compared. Simulation results prove that the separated positive and negative sequence controllers limit the torque pulsation and dc voltage ripple effectively.","control; doubly fed induction generator (DFIG); operation; unbalanced","en","journal article","IEEE","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Electrical Sustainable Energy","","","",""
"uuid:43979d17-9d47-49cb-84e5-f9b93f0c4c74","http://resolver.tudelft.nl/uuid:43979d17-9d47-49cb-84e5-f9b93f0c4c74","On the vorticity characteristics of lobe-forced mixer at different configurations","mao, R.; Yu, S.C.M.; Zhou, T.; Chua, L.P.","","2009","Lobe-forced mixer is one typical example of the passive flow controllers owing to its corrugated trailing edge. Besides the spanwise Kelvin–Helmholtz vortex shedding, streamwise vortices are also generated within its mixing layer. The geometrical configuration of the lobe significantly affects these two types of vortices, which in turn affects the mixing performance of the mixer. In the present investigation, characteristics of mixers with five different configurations were examined and evaluated for two velocity ratios (r = 1, 0.4). The mixers have only one lobe in order to eliminate any possible interactions between neighboring vortices generated by the adjacent lobes. Hot-wire anemometer was used to examine the Kelvin–Helmholtz vortices via the spectrum analysis while laser Doppler anemometer was employed to examine the streamwise vortices. It was found that there were two main frequencies for the Kelvin–Helmholtz vortices in the wake of the mixer; and the Strouhal numbers approached their respective maximum values at high Reynolds number. The rectangular mixer had similar mixing performance with the semicircular one; and both of them were better than the triangular mixer. The scalloping modification enhanced mixing by generating additional streamwise vortices while the scarfing modification could not improve the mixing performance.","","en","journal article","Springer","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:e0bed8de-2baa-4624-a779-a35aa687942d","http://resolver.tudelft.nl/uuid:e0bed8de-2baa-4624-a779-a35aa687942d","Evolution of Grain Boundary Phases during the Homogenization of AA7020 Aluminum Alloy","Eivani, A.R.; Ahmed, H.; Zhou, J.; Duszczyk, J.","","2009","The presence of large constitutive particles formed during solidification decreases the strength and hot workability of aluminum alloys especially when they are located in the grain boundary (GB) regions. Therefore, the evolution of these phases is a major issue in the homogenization process of these alloys. There is a lack of information on the behavior of the GB phases during homogenization, which constitute more than 70 pct of all the secondary phases present in the microstructure of AA7020 aluminum alloys. The dominant GB phase is identified to be Al-17(Fe3.2Mn0.8)Si-2. In the present research, a comprehensive study on the effect of the homogenization treatment on the evolution of the GB phases during homogenization was conducted. The analysis shows that the evolution of this phase is largely dependent on temperature, which ranges from spheroidization with insignificant dissolution at low temperatures to full dissolution during homogenization at high temperatures. A new mechanism for the dissolution of these phases called thinning, discontinuation, and full dissolution (TDFD) is proposed based on the findings of the field emission gun-scanning electron microscope (FEG-SEM) analysis.","","en","journal article","Springer","","","","","","","","Mechanical, Maritime and Materials Engineering","Materials Science and Engineering","","","",""
"uuid:a50d186f-ef4f-4e9b-8f9e-f063e7abac25","http://resolver.tudelft.nl/uuid:a50d186f-ef4f-4e9b-8f9e-f063e7abac25","Strain-dependent constitutive analysis of three wrought Mg–Al–Zn alloys","Slooff, F.A.; Zhou, J.; Duszczyk, J.; Katgerman, L.","","2008","The commonly used hyperbolic sine constitutive equation for metal forming at elevated temperatures, with no strain incorporated, is in principle applicable only to deformation in the steady state. However, the actual deformation processes applied to magnesium alloys are mostly in the non-steady state. In the present research, the results of hot uniaxial compression tests of three wrought magnesium alloys covering wide ranges of temperatures and strain rates were used for a strain-dependent constitutive analysis. A strain-dependent constitutive relationship for these alloys was established. It appeared that the apparent activation energy for deformation decreased with increasing the alloying content in these alloys. The constitutive parameters obtained were used to predict flow stresses at given strains and the results were in good agreement with experimental measurements.","","en","journal article","Springer","","","","","","","","Mechanical, Maritime and Materials Engineering","Materials Science and Engineering","","","",""
"uuid:33a06c9c-86c7-41e4-8a2b-89f6ebdadaab","http://resolver.tudelft.nl/uuid:33a06c9c-86c7-41e4-8a2b-89f6ebdadaab","Reformulating Component Identification as Document Analysis Problem","Gross, H.G.; Lormans, M.; Zhou, J.","","2007","One of the first steps of component procurement is the identification of required component features in large repositories of existing components. On the highest level of abstraction, component requirements as well as component descriptions are usually written in natural language. Therefore, we can reformulate component identification as a text analysis problem and apply latent semantic analysis for automatically identifying suitable existing components in large repositories, based on the descriptions of required component features. In this article, we motivate our choice of this technique for feature identification, describe how it can be applied to feature tracing problems, and discuss the results that we achieved with the application of this technique in a number of case studies. Paper accepted for publication in ICSOFT 2007, Proceedings of the Second International Conference on Software and Data Technologies, Volume SE, Barcelona, Spain, July 22-25, 2007.","Latent Semantic Analysis; Component Identification; Component Selection; Procurement Automation","en","report","Delft University of Technology, Software Engineering Research Group","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Software Technology","","","",""
"uuid:cf403aa4-3100-4718-9b56-e2761c2ffde9","http://resolver.tudelft.nl/uuid:cf403aa4-3100-4718-9b56-e2761c2ffde9","Network-aware SuperPeers-Peers Geometric Overlay Network","Lua, E.K.; Zhou, X.","","2007","Peer-to-Peer (P2P) overlay networks can be utilized to deploy massive Internet overlay services such as multicast, content distribution, file sharing, etc. efficiently without any underlying network support. The crucial step to meet this objective is to design network-aware overlay network topologies connecting all nodes that offer promising properties in terms of excellent communication quality. We exploit the underlying network locality and proximity of the nodes for overlay routing and node placement strategy. In this paper, we describe in greater specific details our network-aware SuperPeers-Peers geometric overlay network hierarchy and study its communication quality in a massive scale network environment. We evaluate our proposal using ten massive scale networks each consisting of 100, 000 nodes. Our experimental results show high communication efficiency, quality and performance.","","en","conference paper","IEEE","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Network Architectures and Services","","","",""
"uuid:1a4df991-0625-4875-9e48-3907741a0ecd","http://resolver.tudelft.nl/uuid:1a4df991-0625-4875-9e48-3907741a0ecd","Towards Software Component Procurement Automation","Gross, H.G.; Lormans, M.; Zhou, J.","","2007","One of the first steps of component procurement is the identification of required component features in large repositories of existing components. On the highest level of abstraction, component requirements as well as component descriptions are usually written in natural language. Therefore, we can reformulate component procurement as a text analysis problem and apply latent semantic analysis for automatically identifying suitable existing components in large repositories, based on the descriptions of required component features. In this article, we motivate our choice of this technique for feature identification, describe how it can be applied to feature tracing problems, and discuss the results that we achieved with the application of this technique in a number of case studies. Preprint accepted for publiction in: Third International Workshop on Coordination and Adaptation Techniques for Software Entities. WCAT’06, July 4th, 2006, Nantes, France","Software Component; Repository; Feature Mapping; Document Analysis","en","report","Delft University of Technology, Software Engineering Research Group","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Software Technology","","","",""
"uuid:90ed9231-23b0-468f-a474-36707d0c150e","http://resolver.tudelft.nl/uuid:90ed9231-23b0-468f-a474-36707d0c150e","Control of DFIG under unsymmetrical voltage dip","Zhou, Y.; Bauer, P.; Ferreira, J.A., Pierik, J.","","2007","","","en","conference paper","IEEE","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:a09e4c35-57c8-4f47-834e-60365354ff72","http://resolver.tudelft.nl/uuid:a09e4c35-57c8-4f47-834e-60365354ff72","Grid-connected and islanded operation of a hybrid power system","Zhou, Y.; Ferreira, J.A.; Bauer, P.","","2007","","","en","conference paper","IEEE","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:9da003c3-0a23-4f09-a65b-25d2435e5103","http://resolver.tudelft.nl/uuid:9da003c3-0a23-4f09-a65b-25d2435e5103","On the availability of networks","Zhou, W; Janic, M (TU Delft International Research Centre for Telecommunication and Radar); Kooij, Robert (TU Delft International Research Centre for Telecommunication and Radar); Kuipers, F.A. (TU Delft Network Architectures and Services)","","2007","","conference contrib. refereed; Conf.proc. > 3 pag","en","conference paper","IET","","","","","","","","","","International Research Centre for Telecommunication and Radar","","",""
"uuid:060fc436-07fe-47f8-b418-d53e8fb2c75c","http://resolver.tudelft.nl/uuid:060fc436-07fe-47f8-b418-d53e8fb2c75c","Measuring the internet","Zhou, X.","van Mieghem, P. (promotor)","2006","The Internet is a collection of networks that use the TCP/IP suite of protocols. It has a huge impact on human activity. There are currently hundreds of millions of computers connected to the Internet, generating several petabytes traffic a day. Internet is still growing rapidly. However, the Internet today is not yet precisely characterized. One reason for this is that it is dynamic, constantly changing in size, traffic load, and application types. Recently, there has been a lot of effort put into various aspects of Internet measurements. These are important to the scientists as they provides crucial, fundamental knowledge about Internet structure and performance, and, at the same time, these measurements have added value for Internet Service Providers (ISPs) in terms of service monitoring and for management purposes. Results obtained so far in Internet measurements are very encouraging. Significant progress has been made in many fields (e.g., we now understand the topology of Web much better than before), but there are still many aspects of that the Internet's structure, workload, and applications that are unexplored. This thesis addresses several unanswered questions about the performance of the Internet at the network and the application layer. To mention a few: 1. How can we model the Internet infrastructure, and how can this be measured? 2. How does IPv6 compare to IPv4 in terms of delay and loss performance and how has performance evolved over the past few years? 3. How can we evaluate user application performance through Internet measurements? 4. Is there any method to estimate network distance based on reduced or incomplete measurements (e.g., delay and hopcount)? This thesis intends to address these questions by measuring the Internet and analyzing empirical evidence obtained from Internet data. In this thesis, we show that accurate measurements not only enhance our understanding of the current Internet, but can also lead to recommendations for improvements on both the network infrastructure and network protocols.","internet; measurement; network-layer; application-layer","en","doctoral thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:f50e17b3-3f88-4894-9d9a-5fee927b9fa1","http://resolver.tudelft.nl/uuid:f50e17b3-3f88-4894-9d9a-5fee927b9fa1","Computational study of enzyme enantioselectivity","Zhou, Yu","De Leeuw, S.W. (promotor); Hagen, W.R. (promotor)","2006","Abstract not available","","en","doctoral thesis","","","","","","","","","Applied Sciences","","","","",""
"uuid:ace056f8-73eb-458a-bf9c-5300e399f689","http://resolver.tudelft.nl/uuid:ace056f8-73eb-458a-bf9c-5300e399f689","A Hybrid Five-Point Finite Difference Scheme for Convection-Diffusion Equations","Jing, H.; Li, C.; Zhou, B.","","2006","In this paper, some five-point finite difference schemes for steady convection-diffusion problems are presented. To begin with, we use the finite volume method (FVM) to discretize the convection-diffusion equation. After that, we present two five-point difference schemes for the approximation of the first order derivatives on faces, one of which is central difference type scheme, the other is upwind difference type scheme. In both of the schemes, one node is always connected with its four neighbor nodes. As the central scheme is of fourth order accuracy, it is very accurate to employ for small Peclet numbers. But when Peclet number is large, the scheme can be unstable. In this case, the upwind scheme of third order accuracy is stable. As the upwind scheme can reflect the flow transportation, it can give stable numerical solution. Taking use the advantages of the above two schemes, we construct a hybrid scheme, which can be ap- plied not only for small Peclet numbers, but for large Peclet numbers. The new higher order difference scheme and the hybrid strategy might be extended to solve 2D and 3D fluid dynamics equations includ- ing Navier-Stokes equation. Some numerical examples are also presented to illustrate the discussion.","finite volume method; convection-diffusion equation; hybrid difference scheme; central difference scheme; upwind difference scheme","en","conference paper","","","","","","","","","","","","","",""
"uuid:b6b78000-e481-4f09-9f83-0d13db020c8f","http://resolver.tudelft.nl/uuid:b6b78000-e481-4f09-9f83-0d13db020c8f","Hopcount in the NICE Application Layer Multicast Protocol","Tang, H.; Janic, M.; Zhou, X.","","2006","","application layer multicast; NICE; overlay networks; Hopcount","en","conference paper","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:56fe4372-0d2c-45b8-a6b4-fb86b7dc2d72","http://resolver.tudelft.nl/uuid:56fe4372-0d2c-45b8-a6b4-fb86b7dc2d72","Estimation of Perceived Quality of Service for Applications on IPv6 Network","Zhou, X.; Kooij, R.E.; Uijterwaal, H.; Van Mieghem, P.","","2006","","QoS; Measurement; IPv6","en","conference paper","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:10c081ea-dc15-4bdd-b9cd-89a7ee086929","http://resolver.tudelft.nl/uuid:10c081ea-dc15-4bdd-b9cd-89a7ee086929","High performance repetitive control of PWM DC-AC converters with real-time phase-lead FIR filter","Ye, Y.; Zhou, K.; Wang, D.; Wang, J.C.","","2006","","","en","journal article","Institute of Electrical and Electronics Engineers IEEE","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:ebf33c90-894e-4d31-9206-caf475e7c98c","http://resolver.tudelft.nl/uuid:ebf33c90-894e-4d31-9206-caf475e7c98c","Estimation of Voice over IP Quality in the Netherlands","Zhou, X.; Muller, F.; Kooij, R.E.; Van Mieghem, P.","","2006","","","en","conference paper","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:d69c2f38-167f-4ee9-95b6-1df013098062","http://resolver.tudelft.nl/uuid:d69c2f38-167f-4ee9-95b6-1df013098062","Modelling the Melting of Post-consumer Scrap within a Rotary Melting Furnace for Aluminium Recycling","Zhou, B.","Reuter, M.A. (promotor)","2005","","secondary aluminium; scrap melting; rotary furnace; computational fluid dynamics (CFD); process modelling; population balance model (PBM); sustainability","en","doctoral thesis","","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:dea753ff-1f00-4e93-bb03-eb4c32fdd90d","http://resolver.tudelft.nl/uuid:dea753ff-1f00-4e93-bb03-eb4c32fdd90d","Hierarchical Peer-to-Peer Networks using Lightweight SuperPeer Topologies","Kleis, M.; Keong Lua, E.; Zhou, X.","","2005","","","en","conference paper","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:71ce2ce6-1d19-4efa-ad38-cde70b47e7f5","http://resolver.tudelft.nl/uuid:71ce2ce6-1d19-4efa-ad38-cde70b47e7f5","Effect of shallow and narrow water on added mass of cylinders with various cross-sectional shapes","Zhou, Z.X.","","2005","","hydrodynamics","","journal article","","","","","","","","","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Hydromechanics and Structures","","",""
"uuid:c5c7ff0e-9bda-428f-a65d-2c8f6b99feb6","http://resolver.tudelft.nl/uuid:c5c7ff0e-9bda-428f-a65d-2c8f6b99feb6","Hopcount in Application Layer Multicast Schemes","Janic, M.; Cempaka Wangi, N.I.; Zhou, X.; Van Mieghem, P.","","2005","","","en","conference paper","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:35dd4618-c90f-4462-bae3-87e57c9ce01c","http://resolver.tudelft.nl/uuid:35dd4618-c90f-4462-bae3-87e57c9ce01c","A Case for Lightweight SuperPeer Topologies","Kleis, M.; Keong Lua, E.; Zhou, X.","","2005","","","en","conference paper","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:f73e79dc-c04b-4d87-9304-ca74e0b22a1d","http://resolver.tudelft.nl/uuid:f73e79dc-c04b-4d87-9304-ca74e0b22a1d","Hopcount and E2E Delay: IPv6 Versus IPv4","Zhou, X.; Van Mieghem, P.","","2005","","","en","conference paper","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","","","","",""
"uuid:85d780d8-d827-4de9-9715-9b0d143d6a67","http://resolver.tudelft.nl/uuid:85d780d8-d827-4de9-9715-9b0d143d6a67","An economic solution of ballast water treatment for oil tankers","Zhou, P.","","2002","","construction","","conference paper","","","","","","","","","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Hydromechanics and Structures","","",""
"uuid:75893803-641e-4167-bbcd-82e393d12fdc","http://resolver.tudelft.nl/uuid:75893803-641e-4167-bbcd-82e393d12fdc","Implications for QoS provisioning based on traceroute measurements","Janic, M (TU Delft Network Architectures and Services); Kuipers, F.A. (TU Delft Network Architectures and Services); Zhou, X (TU Delft Network Architectures and Services); Van Mieghem, P.F.A. (TU Delft Network Architectures and Services)","Stiller, B (editor)","2002","","conference contrib. refereed; ZX Nader te bep. ivm conversie; ZX Int.klas.verslagjaar < 2002","en","conference paper","Springer","","","","","","","","","","Network Architectures and Services","","",""
"uuid:8e8ad486-c041-4eac-bbb6-857bc0a9c151","http://resolver.tudelft.nl/uuid:8e8ad486-c041-4eac-bbb6-857bc0a9c151","A model for deposition of fibers in the lung","Zhou, Y.","Bibo, B.H. (promotor)","1997","","","en","doctoral thesis","","","","","","","","","Applied Sciences","","","","",""
"uuid:d38592c8-038a-482b-8a8a-d6e6bbf114f1","http://resolver.tudelft.nl/uuid:d38592c8-038a-482b-8a8a-d6e6bbf114f1","Relative motion prediction with phase lag revisions","Zhou, Z.Q.; Journee, Johan M.J.","","1997","","hydrodynamics","","report","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Hydromechanics and Structures","","",""
"uuid:932ae543-004f-452e-b79a-3dac73108d3f","http://resolver.tudelft.nl/uuid:932ae543-004f-452e-b79a-3dac73108d3f","Non-linear influence of flare on ship hull girder loads in waves","Zhou, Z.Q.; Journee, Johan M.J.","","1997","","hydrodynamics","","report","","","","","","","","indefinite","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Hydromechanics and Structures","","",""
"uuid:a3bd54b3-0a3c-44fa-b346-e0a5768a7653","http://resolver.tudelft.nl/uuid:a3bd54b3-0a3c-44fa-b346-e0a5768a7653","A seakeeping experiment research on Flokstra container ship model","Zhou, Zheng-Quan; Zhou, De-Cai; Xie, Nan","","1996","","hydrodynamics","","report","","","","","","","","","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Hydromechanics and Structures","","",""
"uuid:c5507de6-f53e-4af4-a9f0-599505b46007","http://resolver.tudelft.nl/uuid:c5507de6-f53e-4af4-a9f0-599505b46007","Towards an Operational Risk Assessment in Flood Alleviation: Theory, operationalization and application","Zhou, H.M.","Pols, A.A.J. (promotor); Vrijling, J.K. (promotor)","1995","","flood alleviation; dike heightening; uncertainty assessment","en","doctoral thesis","Delft University Press","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:42ebee9b-5388-4f99-9ee9-ce92643dd80a","http://resolver.tudelft.nl/uuid:42ebee9b-5388-4f99-9ee9-ce92643dd80a","An integrated method for computing the internal and external viscous flow field around the ducted propulsor behind an axisymmetric body","Zhou, Lian-di; Feng, Zhao","","1994","","resistance & propulsion","","report","","","","","","","","","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Hydromechanics and Structures","","",""
"uuid:bf3121af-b524-494a-ae91-85974c0fb0f5","http://resolver.tudelft.nl/uuid:bf3121af-b524-494a-ae91-85974c0fb0f5","Application of radon transforms to the processing of airborne geophysical data","Zhou, Y.","Ziolkowski, A.M. (promotor)","1992","","","en","doctoral thesis","","","","","","","","","Civil Engineering and Geosciences","","","","",""
"uuid:1c53601c-9cdd-454c-9bb4-56638c1b8651","http://resolver.tudelft.nl/uuid:1c53601c-9cdd-454c-9bb4-56638c1b8651","Extrusion of Al-Si-X alloys prepared from rapidly solidified powders","Zhou, J.","Korevaar, B.M. (promotor)","1991","","","en","doctoral thesis","","","","","","","","","Mechanical Maritime and Materials Engineering","","","","",""
"uuid:6998729f-b32f-4c28-84a5-fd9b74c304b8","http://resolver.tudelft.nl/uuid:6998729f-b32f-4c28-84a5-fd9b74c304b8","Numerical computation of ship motions in directional seas. Part I. Frequency domain analysis","Zhou, Xingbang","","1988","","hydrodynamics","","report","","","","","","","","","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Hydromechanics and Structures","","",""
"uuid:e31e3c02-d6ab-41f6-99f9-62b2f8c2b673","http://resolver.tudelft.nl/uuid:e31e3c02-d6ab-41f6-99f9-62b2f8c2b673","A streamline-interaction method for calculating turbulent flow around the stern of a body of revolution and its wake","Zhou, Lian-di","","1986","","resistance & propulsion","","report","","","","","","","","","Mechanical, Maritime and Materials Engineering","Marine and Transport Technology","Ship Hydromechanics and Structures","","",""