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Imperfection-induced internal resonance in nanotube resonators

Belardinelli, P. (author), Lenci, S. (author), Alijani, F. (author)

Through molecular dynamics simulations, we demonstrate the possibility of internal resonances in single-walled carbon nanotubes. The resonant condition is engineered with a lack of symmetry in the boundary condition and activated by increasing the energy exchange with a coupled thermal bath. The critical temperature threshold for initiating...

journal article 2024

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Microscopic insights into poly- and mono-crystalline methane hydrate dissociation in Na-montmorillonite pores at static and dynamic fluid conditions

Fang, B. (author), Lü, Tao (author), Li, Wei (author), Moultos, O. (author), Vlugt, T.J.H. (author), Ning, Fulong (author)

Knowledge on the kinetics of gas hydrate dissociation in clay pores at static and dynamic fluid conditions is a fundamental scientific issue for improving gas production efficiency from hydrate deposits using thermal stimulation and depressurization respectively. Here, molecular dynamics simulations were used to investigate poly- and mono...

journal article 2024

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Finite element-based framework to study the response of bituminous concrete pavements under different conditions

Kumar, Abhinav (author), Gupta, Ankit (author), Anupam, K. (author), Wagh, Vivek Pratap (author)

In most of developing countries across the world, pavement design is still based on an empirical approach that may result in premature failure or overdesigned pavements. A shift from an empirical to a semi-mechanistic or mechanistic approach is the need of modern time. In this regard, computational tools such as finite element (FE) are being...

journal article 2024

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Experimental study on workability and permeability of sandy soils conditioned with thickened foam

Feng, Zhiyao (author), Wang, Shuying (author), Qu, Tongming (author), Zheng, X. (author), Ling, Fanlin (author)

Water spewing and muck plugging often occur during earth pressure balance (EPB) shield machines tunnelling in water-rich sandy strata, even though the conventional foam has been employed to condition sandy soils. In this study, a novel thickened foaming agent suitable for EPB shield tunnelling in water-rich sandy strata is developed. In...

journal article 2024

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Optimal chartering decisions for vessel fleet to support offshore wind farm maintenance operations

Li, M. (author), Bijvoet, Bas (author), Wu, Kangjie (author), Jiang, X. (author), Negenborn, R.R. (author)

Offshore wind energy is expected to be the most significant source of future electricity supply in Europe. Offshore wind farms are located far from the shores, requiring a fleet of various types of vessels to access sites when maintaining offshore wind turbines. The employment of the vessels is costly, accounting for the majority of the total...

journal article 2024

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Autonomous Sensor System for Low-Capacity Wind Turbine Blade Vibration Measurement

Muxica, Diego (author), Rivera, Sebastian (author), Orchard, Marcos E. (author), Ahumada, Constanza (author), Jaramillo, Francisco (author), Bravo, Felipe (author), Gutiérrez, José M. (author), Astroza, Rodrigo (author)

This paper presents the design, implementation, and validation of an on-blade sensor system for remote vibration measurement for low-capacity wind turbines. The autonomous sensor system was deployed on three wind turbines, with one of them operating in harsh weather conditions in the far south of Chile. The system recorded the acceleration...

journal article 2024

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Condition-Based Maintenance scheduling of an aircraft fleet under partial observability: A Deep Reinforcement Learning approach

Tseremoglou, I. (author), Santos, Bruno F. (author)

In the Condition-Based Maintenance (CBM) context, the definition of optimal maintenance plans for an aircraft fleet depends on an efficient integration of : (i) the probabilistic predictions of the health condition of the components and (ii) the stochastic arrival of the corrective maintenance tasks, together with consideration of the...

journal article 2024

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A generating absorbing boundary condition for simulating wave interaction with maritime structures in current or at forward speed

Chang, X. (author), Wellens, P.R. (author)

The lack of suitable boundary conditions in practical surface wave simulations with maritime structures in current or at forward speed may cause energy in the computational domain to accumulate due to spurious wave reflection. The common way to prevent wave reflection is to use passive wave absorbers, such as damping zones or relaxation zones...

journal article 2024

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Successive approximations and interval halving for fractional BVPs with integral boundary conditions

Marynets, K. (author), Pantova, D.H. (author)

We study a system of non-linear fractional differential equations, subject to integral boundary conditions. We use a parametrization technique and a dichotomy-type approach to reduce the original problem to two “model-type” fractional boundary value problems with linear two-point boundary conditions. A numerical-analytic technique is applied...

journal article 2024

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Advancing railway track health monitoring: Integrating GPR, InSAR and machine learning for enhanced asset management

Koohmishi, Mehdi (author), Kaewunruen, Sakdirat (author), Chang, L. (author), Guo, Y. (author)

Railway track health monitoring and maintenance are crucial stages in railway asset management, aiming to enhance the train operation quality and service life. For this aim, various inspection means (using diverse non-destructive testing techniques) have been applied, however, these means are mostly not able to monitor whole railway track...

review 2024

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L^p-estimates for the square root of elliptic systems with mixed boundary conditions II

Bechtel, S. (author)

We show L^p-estimates for square roots of second order complex elliptic systems L in divergence form on open sets in R^d subject to mixed boundary conditions. The underlying set is supposed to be locally uniform near the Neumann boundary part, and the Dirichlet boundary part is Ahlfors–David regular. The lower endpoint for...

journal article 2024

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Fractional periodic boundary value and Cauchy problems with Hilfer–Prabhakar operator

Marynets, K. (author), Tomovski, Živorad (author)

We introduce a successive approximations method to study one fractional periodic boundary value problem of the Hilfer-Prabhakar type. The problem is associated to the corresponding Cauchy problem, whose solution depends on an unknown initial value. To find this value we numerically solve the so-called ’determining system’ of algebraic or...

journal article 2024

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Input Decoupling of Lagrangian Systems via Coordinate Transformation: General Characterization and its Application to Soft Robotics

Pustina, P. (author), Della Santina, C. (author), Boyer, Frederic (author), De Luca, Alessandro (author), Renda, Federico (author)

Suitable representations of dynamical systems can simplify their analysis and control. On this line of thought, this article aims to answer the following question: Can a transformation of the generalized coordinates under which the actuators directly perform work on a subset of the configuration variables be found? We not only show that the...

journal article 2024

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A linear matrix inequality approach to optimal reset control design for a class of nonlinear systems

Shahbazzadeh, Majid (author), Sadati, S. Jalil (author), Hassan HosseinNia, S. (author)

In this article, the problem of the optimal reset control design for Lipschitz nonlinear systems is addressed. The reset controller includes a base linear controller and a reset law that enforces resets to the controller states. The reset law design is strongly dependent on the appropriate design of the base controller. For this reason, in...

journal article 2024

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A model for modifying the S-N curve considering the effect of boundary conditions on the fatigue crack growth of welded components

Shakeri, I. (author), Wu, W. (author), Michel, Alexander (author), Eder, Martin A. (author)

The present study proposes a novel model to modify master S-N curves of components according to their load redistribution capability reflected in different boundary conditions (BCs) based on the fracture mechanics analysis. To that end, a comprehensive numerical study was conducted on a Single Edge Notch Bend (SENB) specimen constrained with...

journal article 2024

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Generic approach towards a diagnostic and prognostic data suitability assessment

Bieber, M.T. (author)

Spacecraft and aircraft systems collect health-related data continuously, which can give an indication of the systems' health status. While they rarely occur, the repercussions of such system anomalies, faults, or failures can be severe, safety-critical and costly. Therefore, the data are used to anticipate any kind of anomalous behaviour or...

doctoral thesis 2023

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Condition assessment of underground corroded pipelines subject to hydrogen damage and combined internal pressure and axial compression

Qin, Guojin (author), Zhang, Zhenwei (author), Hou, Xiangqin (author), Lu, Hongfang (author), Huang, Y. (author), Wang, Yihuan (author)

In this work, a 3D finite element (FE) based model was developed to assess the condition of an underground hydrogen transmission pipeline containing a corrosion defect under combined internal pressure and soil movement-induced axial compression. The use of mechanical properties of X100 pipeline steel under different hydrogen charging time...

journal article 2023

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Probing the hyperfine structure of Fe-based water-gas shift catalysts

Ariëns, M.I. (author)

Hydrogen gas is an essential reagent in numerous industrial processes including ammonia synthesis. Ammonia is a key intermediate in the synthesis of nitrogen-based fertilisers, e.g. nitrates and urea. According to recent estimates (2008), approximately half of the world population is fed by nitrogen-based fertilisers of synthetic origin....

doctoral thesis 2023

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Analogical Assessment of Train-Induced Vibration and Radiated Noise in a Proposed Theater

Liu, X. (author), Xiao, Yuchun (author), Jiang, Huihuang (author), Guo, Y. (author), Yu, Mengwen (author), Tan, Wanzhong (author)

This study presents the analogical assessment of the train-induced vibration and radiated noise in a proposed theater. The theater is to be constructed in a region with crowded metro lines, and the assessment is implemented in an analogical building with comparable structural type and metro condition. Prior to the assessment, the comparability...

journal article 2023

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A Comparative Study of Optimization Models for Condition-Based Maintenance Scheduling of an Aircraft Fleet

Tseremoglou, I. (author), van Kessel, Paul J. (author), Santos, Bruno F. (author)

Condition-based maintenance (CBM) scheduling of an aircraft fleet in a disruptive environment while considering health prognostics for a set of systems is a very complex combinatorial problem, which is becoming more challenging in light of the uncertainty included in health prognostics. This type of problem falls under the broad category of...

journal article 2023