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A scanning focus nuclear microscope with multi-pinhole collimation

Nguyen, M.P. (author), Arif, M. (author), Oostenrijk, Bart (author), Goorden, M.C. (author), Beekman, F.J. (author)

Microscopic nuclear imaging down to spatial resolutions of a few hundred microns can already be achieved using low-energy gamma emitters (e.g. ¹²⁵I, ∼30 keV) and a basic single micro-pinhole gamma camera. This has been applied to in vivo mouse thyroid imaging, for example. For clinically used radionuclides such as ^99mTc,...

journal article 2023

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Conceptual design of compliant bone scaffolds by full-scale topology optimization

Smit, Thijs (author), Koppen, S. (author), Ferguson, Stephen J. (author), Helgason, Benedikt (author)

A promising new treatment for large and complex bone defects is to implant specifically designed and additively manufactured synthetic bone scaffolds. Optimizing the scaffold design can potentially improve bone in-growth and prevent under- and over-loading of the adjacent tissue. This study aims to optimize synthetic bone scaffolds over...

journal article 2023

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Using continuous electrical conductivity measurements to derive major solute concentrations in karst systems

Richieri, Beatrice (author), Bittner, Daniel (author), Hartmann, Andreas (author), Benettin, Paolo (author), van Breukelen, B.M. (author), Labat, David (author), Chiogna, Gabriele (author)

Hydrochemical data of karst springs provide valuable insights into the internal hydrodynamical functioning of karst systems and support model structure identification. However, the collection of high-frequency time series of major solute species is limited by analysis costs. In this study, we develop a method to retrieve the individual solute...

journal article 2023

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Atrial extrasystoles enhance low-voltage fractionation electrograms in patients with atrial fibrillation

van Schie, M.S. (author), Liao, Rongheng (author), Ramdat Misier, Nawin L. (author), Knops, Paul (author), Heida, Annejet (author), Taverne, Yannick J.H.J. (author), de Groot, N.M.S. (author)

BACKGROUND AND AIMS: Atrial extrasystoles (AES) provoke conduction disorders and may trigger episodes of atrial fibrillation (AF). However, the direction- and rate-dependency of electrophysiological tissue properties on epicardial unipolar electrogram (EGM) morphology is unknown. Therefore, this study examined the impact of spontaneous AES on...

journal article 2023

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A Hybrid Magnetic Current Sensor With a Dual Differential DC Servo Loop

Jouyaeian, A. (author), Fan, Q. (author), Ausserlechner, Udo (author), Motz, Mario (author), Makinwa, K.A.A. (author)

This article presents a hybrid magnetic current sensor for contactless current measurement. Pick-up coils and Hall plates are employed to sense the high and low-frequency fields, respectively, generated by a current-carrying conductor. Due to the differentiating characteristic of the pick-up coils, a flat frequency response can then be...

journal article 2023

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Chessboard Focal Plane Array for a CMOS-Integrated Terahertz Camera

Hoogelander, M. (author), van Berkel, S.L. (author), Malotaux, E.S. (author), Alonso Del Pino, M. (author), Cavallo, D. (author), Spirito, M. (author), Llombart, Nuria (author)

This article presents the development of a focal plane array (FPA) for terahertz imaging applications with a near diffraction-limited resolution achieved through a very tight sampling of the focal plane. The antenna array is integrated with direct detectors in a 22-nm CMOS technology and operates from 200 to 600 GHz. The tight sampling of the...

journal article 2023

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A data-driven high spatial resolution model of biomass accumulation and crop yield: Application to a fragmented desert-oasis agroecosystem

Chen, Qiting (author), Jia, Li (author), Menenti, M. (author), Hu, Guangcheng (author), Wang, Kun (author), Yi, Zhiwei (author), Zhou, Jie (author), Peng, Fei (author), Ma, Shaoxiu (author)

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...

journal article 2023

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A 4-μW Bandwidth/Power Scalable Delta-Sigma Modulator Based on Swing-Enhanced Floating Inverter Amplifiers

Zhao, Menglian (author), Zhao, Yibo (author), Zhang, H. (author), Hu, Yaopeng (author), Bao, Yuanxin (author), Ye, Le (author), Qu, Wanyuan (author), Tan, Zhichao (author)

This article presents a fully dynamic scalable switched-capacitor delta-sigma modulator that achieves a 94.1-dB dynamic range (DR). Power-and- bandwidth scalability by only changing the clock frequency is achieved using a capacitively biased and swing-enhanced floating inverter operational transconductance amplifier (OTA). Fabricated in a 180...

journal article 2022

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High-Resolution Free-Breathing Quantitative First-Pass Perfusion Cardiac MR Using Dual-Echo Dixon With Spatio-Temporal Acceleration

Tourais, Joao (author), Scannell, Cian M. (author), Schneider, Torben (author), Alskaf, Ebraham (author), Crawley, Richard (author), Bosio, Filippo (author), Sanchez-Gonzalez, Javier (author), Doneva, Mariya (author), Schülke, Christophe (author)

Introduction: To develop and test the feasibility of free-breathing (FB), high-resolution quantitative first-pass perfusion cardiac MR (FPP-CMR) using dual-echo Dixon (FOSTERS; Fat-water separation for mOtion-corrected Spatio-TEmporally accelerated myocardial peRfuSion). Materials and Methods: FOSTERS was performed in FB using a dual...

journal article 2022

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Efficient Monte-Carlo based system modelling for image reconstruction in preclinical pinhole SPECT

Nguyen, M.P. (author), Goorden, M.C. (author), Ramakers, R.M. (author), Beekman, F.J. (author)

The use of multi-pinhole collimation has enabled ultra-high-resolution imaging of SPECT and PET tracers in small animals. Key for obtaining high-quality images is the use of statistical iterative image reconstruction with accurate energy-dependent photon transport modelling through collimator and detector. This can be incorporated in a system...

journal article 2021

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Observing the impact of urban morphology and building geometry on thermal environment by high spatial resolution thermal images

Yang, Jinxin (author), Shi, Qian (author), Menenti, M. (author), Wong, Man Sing (author), Wu, Zhifeng (author), Zhao, Qunshan (author), Abbas, Sawaid (author), Xu, Yong (author)

Urban surface temperature is a very important variable in the observation and understanding of energy exchange. A comprehensive understanding of the urban thermal environment is of great significance towards the adaptability of urban areas to climate hazards. The heterogeneity of urban space increases the complexity of the urban surface...

journal article 2021

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An Integrated Multiscale Method for the Characterisation of Active Faults in Offshore Areas. The Case of Sant’Eufemia Gulf (Offshore Calabria, Italy)

Corradino, M. (author), Pepe, F. (author), Burrato, P. (author), Kanari, M. (author), Parrino, N. (author), Bertotti, G. (author), Bosman, A. (author), Casalbore, D. (author), Ferranti, L. (author)

Diagnostic morphological features (e.g., rectilinear seafloor scarps) and lateral offsets of the Upper Quaternary deposits are used to infer active faults in offshore areas. Although they deform a significant seafloor region, the active faults are not necessarily capable of producing large earthquakes as they correspond to shallow structures...

journal article 2021

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Shear-slip behaviour of prefabricated composite shear stud connectors in composite bridges

Gao, Yanmei (author), Li, Chengjun (author), Wang, Xuefei (author), Zhou, Zhixiang (author), Fan, Liang (author), Heng, J. (author)

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....

journal article 2021

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Cross-sectional characterization of the conversion layer formed on AA2024-T3 by a lithium-leaching coating

Kosari, A. (author), Visser, P. (author), Tichelaar, F.D. (author), Eswara, S. (author), Audinot, J. N. (author), Wirtz, T. (author), Zandbergen, H.W. (author), Terryn, H.A. (author), Mol, J.M.C. (author)

This work focuses on the cross-sectional characterization of the protective conversion layer formed on AA2024-T3 by lithium-leaching from a polyurethane coating in a corrosive environment. The layer shows a multi-layered arrangement comprising nanoscopic local phases. Transmission electron microscopy (TEM) and complementary high-resolution...

journal article 2020

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Automatic high-resolution microseismic event detection via supervised machine learning

Qu, S. (author), Guan, Zhe (author), Verschuur, D.J. (author), Chen, Yangkang (author)

Microseismic methods are crucial for real-Time monitoring of the hydraulic fracturing dynamic status during the development of unconventional reservoirs. However, unlike the active-source seismic events, the microseismic events usually have low signal-To-noise ratio (SNR), which makes its data processing challenging. To overcome the noise...

journal article 2020

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Missed Fog?: On the Potential of Obtaining Observations at Increased Resolution During Shallow Fog Events

Izett, J.G. (author), Schilperoort, Bart (author), Coenders-Gerrits, Miriam (author), Baas, P. (author), Bosveld, Fred C. (author), van de Wiel, B.J.H. (author)

Conventional in situ observations of meteorological variables are restricted to a limited number of levels near the surface, with the lowest observation often made around 1-m height. This can result in missed observations of both shallow fog, and the initial growth stage of thicker fog layers. At the same time, numerical experiments have...

journal article 2019

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Homogenization-based stiffness optimization and projection of 2D coated structures with orthotropic infill

Groen, J.P. (author), Wu, J. (author), Sigmund, Ole (author)

This paper concerns compliance minimization and projection of coated structures with orthotropic infill material in 2D. The purpose of the work is two-fold. First, we introduce an efficient homogenization-based approach to perform topology optimization of coated structures with orthotropic infill material. The design space is relaxed to allow...

journal article 2019

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Beam-Switch Wide-Swath Mode for Interferometrically Compatible Single-Pol and Quad-Pol SAR Products

Bordoni, Federica (author), Lopez Dekker, F.J. (author), Krieger, Gerhard (author)

Future spaceborne synthetic aperture radar (SAR) systems are expected to deliver enormous quantity of data. Accordingly, the observation plan becomes crucial for a proper allocation of the mission resources. A central challenge is to reduce the number of acquisitions by making the same image available for more applications. Here, a relevant...

journal article 2018

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Self-Aligning and Self-Calibrating Capacitive Sensor System for Displacement Measurement in Inaccessible Industrial Environments

van de Ven, Oscar S. (author), Vogel, J.G. (author), Xia, Sha (author), Spronck, J.W. (author), Nihtianova, S. (author)

High-precision positioning often requires high speed and high resolution displacement measurements in order to compensate for the small vibrations of critical components. The displacement sensor must be precise and stable over a long period of time to avoid expensive recalibration. This requires tight mounting tolerances, which are especially...

journal article 2018

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Light control of the nanoscale phase separation in heteroepitaxial nickelates

Mattoni, G. (author), Manca, N. (author), Hadjimichael, M. (author), Zubko, P. (author), van der Torren, J.H. (author), Yin, C. (author), Catalano, S. (author), Gibert, M. (author), Maccherozzi, F. (author), Liu, Y. (author), Dhesi, S.S. (author), Caviglia, A. (author)

Strongly correlated materials show unique solid-state phase transitions with rich nanoscale phenomenology that can be controlled by external stimuli. Particularly interesting is the case of light–matter interaction in the proximity of the metal–insulator transition of heteroepitaxial nickelates. In this work, we use near-infrared laser light in...

journal article 2018