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IEEE International Conference on Rehabilitation Robotics (ICORR)

作者： Ai Nakamura Shota Ishigaki Yoshifumi Morita Hirofumi Tanabe Department of Engineering Electrical and Mechanical Engineering Program Nagoya Institute of Technology Aichi Japan Department of Electrical and Mechanical Engineering Nagoya Institute of Technology Aichi Japan Department of Health Science Shonan University of Medical Sciences Kanagawa Japan

ISBN: (数字)9781665488297

ISBN: (纸本)9781665488303

Applying an external force to a person’s hyperextended fingertip produces electrical activity in the extensor digitorum communis, even if the person does not try to open their hand. Based on this, a finger extensor facilitation technique conducted by therapists was developed. In this study, we developed a finger extensor facilitation training device named iPARKO that imitates this technique. We examined the relationship between the metacarpophalangeal (MP) joint angle of the four fingers and the activities in the extensor digitorum communis resulting from active training using iPARKO. At the same time, the relationship between the MP joint angle and the reduced activities in the flexor digitorum superficialis was also examined. The experiments were conducted on five healthy subjects. It was found that as the MP joint approached its own maximum hyperextension position, the amount of activity of the extensor digitorum communis increased, and the amount of activity of the flexor digitorum superficialis decreased.

关键词： Training Force Pressing Muscles Stroke (medical condition) Assistive robots Sensors

Machine learning driven search of hydrogen storage materials

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arXiv

arXiv 2025年

作者： Banerjee, Tanumoy Ji, Kevin Xia, Weiyi Ouyang, Gaoyuan Del Rose, Tyler Hlova, Ihor Z. Ueland, Benjamin Johnson, Duane D. Wang, Cai-Zhuan Balasubramanian, Ganesh Singh, Prashant Ames Na[onal Laboratory US Department of Energy Iowa State University AmesIA50011 United States Department of Mechanical and Industrial Engineering University of New Haven West HavenCT06516 United States Department of Materials Science & Engineering Iowa State University AmesIA50011 United States

The transiHon to a low-carbon economy demands efficient and sustainable energy-storage soluHons, with hydrogen emerging as a promising clean-energy carrier and with metal hydrides recognized for their hydrogen-storage capacity. Here, we leverage machine learning (ML) to predict hydrogen-to-metal (H/M) raHos and soluHon energy by incorporaHng thermodynamic parameters and local laTce distorHon (LLD) as key features. Our best-performing ML model provides improvements to H/M raHos and soluHon energies over a broad class of ternary alloys (easily extendable to mulH-principal-element alloys), such as Ti-Nb-X (X = Mo, Cr, Hf, Ta, V, Zr) and Co-Ni-X (X = Al, Mg, V). Ti-Nb-Mo alloys reveal composiHonal effects in H-storage behavior, in parHcular Ti, Nb, and V enhance H-storage capacity, while Mo reduces H/M and hydrogen weight percent by 40-50%. We a`ributed to slow hydrogen kineHcs in molybdenum rich alloys, which is validated by our pressure-composiHon isotherm (PCT) experiments on pure Ti and Ti5Mo95 alloys. Density funcHonal theory (DFT) and molecular simulaHons also confirm that Ti and Nb promote H diffusion, whereas Mo hinders it, highlighHng the interplay between electronic structure, laTce distorHons, and hydrogen uptake. Notably, our Gradient BoosHng Regression model idenHfies LLD as a criHcal factor in H/M predicHons. To aid material selecHon, we present two periodic tables illustraHng elemental effects on (a) H2 wt% and (b) soluHon energy, derived from ML, and provide a reference for idenHfying alloying elements that enhance hydrogen solubility and storage. Copyright © 2025, The Authors. All rights reserved.

关键词： Molybdenum alloys

In Situ TEM Characterizing Basal Dislocations in Mg Channels between Nano-Spaced LPSO Phases

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SSRN 2023年

作者： Liu, Yue Li, Quan Song, Jian Chen, Yiwen Zhang, Qi Zhu, Qing-Chun Wang, Jian Zeng, Xiaoqin National Engineering Research Center of Light Alloy Net Forming State Key Lab of Metal Matrix Composites School of Materials Science and Engineering Shanghai Jiao Tong University Shanghai200240 China Department of Mechanical and Materials Engineering University of Nebraska-Lincoln LincolnNE68588 United States

Long period stacking ordered (LPSO) phases play strong barriers to the motion of nonbasal dislocations and deformation twins, effectively improving the strength of Mg alloys. Corresponding to the crystallographic character of LPSO phases, it is generally believed that LPSO phases would not affect the motion of basal dislocations. Here, we perform in-situ TEM nanoindentation testing on a single crystal Mg97Y2Zn that contains LPSO phases with various spacing within 100 nm, and report on a significantly low activity of basal dislocations in Mg channels with the spacing of LPSO phases less than 20 nm. Atomic HADDF-STEM results reveal a high concentration of solute atoms near LPSO phases, which enhances the solute strengthening effect. These findings may provide possible guidance to design ultra-high strength of Mg alloys with nano-spaced LPSO phases. © 2023, The Authors. All rights reserved.

关键词： Magnesium alloys

Microarchitectural Design Variation of the Echinoid Skeleton: A 3D Structural and mechanical Study of Paracentrotud lividusi

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SSRN 2024年

作者： Perricone, Valentina Cesarano, Pasquale Deb, Mainak Lublin, Derek Mutalipassi, Mirko Pappalardo, Lucia Kisailus, David Marmo, Francesco Department of Materials Science and Engineering University of California Irvine United States Department of Structures for Engineering and Architecture University of Naples Federico II Italy Materials and Manufacturing Technology Program University of California Irvine United States Department of Integrative Marine Ecology Stazione Zoologica Anton Dohrn Villa Comunale Napoli Italy Palermo Italy Italy Wipro Technologies

Biological materials usually show remarkable mechanical properties, despite being composed of fragile and simple components (i.e., strong but brittle minerals and tough but weak proteins). These properties are conferred through a multiscale design, in which shapes, structures and composition are coherently organized leading to unique emerging strategies. Noteworthy is the case of the sea urchin skeleton, a hierarchical tasseled structure composed of multiple calcitic plates that are both lightweight and load-bearing. At the microscale, each plate shows a unique species-specific pattern consisting of a porous 3D lattice-like meshwork of trabeculae, called stereom. Interestingly, the stereom architecture is extremely complex and variable in different basic types, each one characterized by a unique topology and structural behaviors. In this context, the present study provides an in-depth analysis of the microarchitectural variability in the sea urchin Paracentrotus lividus. Accordingly, micro-CT scans, image analysis, 3D modeling, and linear elastic FE-Analysis were conducted to provide new insights about the topological and geometrical variability of the different stereom types, and their region-specific mechanical behavior calculated for tensile and shear loading. These results are of value to ameliorate the understanding of the mechanical function of the stereom variability, as well as to identify adaptive solutions useful for future biomimetic transfer applications. © 2024, The Authors. All rights reserved.

关键词： Finite element method

Numerical comparison of transpiration cooling designs using real gas effects and approximate gas model

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Numerical comparison of transpiration cooling designs using ...

2021 International Conference on Fluid and Chemical engineering, ICFCE 2021

作者： Wang, Meng Wang, Jianhua He, Fei Qian, Kang Wu, Yadong Zhu, Guangsheng CAS Key Laboratory of Mechanical Behaviour and Design of Materials Department of Thermal Science and Energy Engineering University of Science and Technology of China Anhui Hefei230027 China Beijing Institute of Astronautical System Engineering Beijing100076 China

In the severe high-temperature environment caused by aerodynamic heating, the vibrational excitation, dissociation and ionization of gas may successively occur, which are known as real gas effects. Under the real gas effects, the thermodynamic properties of gas vary drastically and significantly influence the performances of the active thermal protection system of hypersonic vehicles, especially in the case with coolant outflow, for example transpiration cooling. This paper numerically investigates the transpiration cooling performance with the consideration of the interaction between coolant outflow and hypersonic flow under the real gas effects. The mathematical models and coupled numerical strategy are firstly validated by experimental data, then the influences of real gas effects on the transpiration cooling of a wedged leading edge (WLE) are studied under a flight Mach number range from 8 to 12 and a flight height of 40 km. The analysis and discussions of the numerical results reveal some important phenomena and demonstrate the need to consider real gas effects.

关键词： Hypersonic vehicles

Synergistically Regulating Particles Size and Defects Level to Realize Fast and Stable Potassium Storage of Carbon Anode

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SSRN 2023年

作者： Li, Yanan Xu, Jinjuan Yuan, Fei Zhang, Di Wang, Qiujun Sun, Huilan Li, Zhaojin Wu, Yimin A. Wang, Bo Hebei Key Laboratory of Flexible Functional Materials School of Materials Science and Engineering Hebei University of Science and Technology Shijiazhuang050000 China Department of Mechanical and Mechatronics Engineering Waterloo Institute of Nanotechnology University of Waterloo WaterlooONN2L 3G1 Canada

A series of defect-rich carbon particles with different sizes are successfully synthesized via a facile synthesis process. Various characterizations demonstrate that the particle size increases with the carbonization time increases, while the defect level presents an opposite trend, and as a result the defect-enriched carbon annealing at 800 ℃ for 2 hours (DEC-800-2) achieves the optimum balance between them, which is favorable for increasing potassium storage sites and improving conductivity. Thus, the DEC-800-2 electrode delivers 220.9 mAh g-1 at 0.5 A g-1 after 100 cycles, accompanied by a good rate capability (156.9 mAh g-1 at 2 A g-1 after 2000 cycles). © 2023, The Authors. All rights reserved.

关键词： Anodes

Strain–Stress Estimation of Vibrational Beam and Plate Using Radiative Energy Transfer Method

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Journal of Applied Mechanics 2025年第6期92卷 061004页

作者： Zhong, Qiang Cui, Ding Xian, Yuqiang Dai, Chenghao Chen, Haibo National Key Laboratory of Science and Technology on Advanced Laser and High Power Microwave Institute of Applied Electronics Chinese Academy of Engineering Physics Mianyang Sichuan 621025 China CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern Mechanics University of Science and Technology of China Hefei Anhui 230027 China

This study aims to present simple conversion expressions of strains–stresses and the energy density for beams and plates subjected to high-frequency random forces using the radiative energy transfer method (RETM). Euler–Bernoulli beam theory and Kirchhoff plate theory are introduced to describe the deflections of beam and plate. The conversion expressions of strains–stresses and energy density for a single propagation wave are quickly established by dispersion relations. For multi-cylindrical wave fields, the strains–stresses are superimposed by the wave fields generated by the actual source in the domain and the wave fields reflected by the fictitious sources at boundaries according to Huygens’ superposition principle. The conversion expressions of strains–stresses and energy density in the energy finite element method (EFEM), which supposes that the superposition of plane waves forms the wave field, are also derived. Numerical examples indicate that in damping-frequency space, the conversion expressions obtained by RETM have a wider application region than those obtained by EFEM and can be applied to a low-frequency band than the corresponding energy algorithm itself.

关键词： vibration Density structures Waves stress analysis Stress wave propagation

Stacking-fault networks with Lomer-Cottrell locks induced by carbon addition in a severely strained Cr-Co-Ni alloy

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Journal of Alloys and Compounds 2025年 1033卷

作者： Stumpf, Guilherme Cardeal Bertoli, Gustavo Coury, Francisco Gil Neta, Augusta Cerceau Isaac Montoro, Luciano Andrey Figueiredo, Roberto Braga Wolf, Witor Graduate Program in Metallurgical Materials and Minning Engineering Federal University of Minas Gerais MG Belo Horizonte31270-901 Brazil Graduate Program in Materials Science and Engineering Federal University of São Carlos Rod. Washington Luiz Km 235 SP São Carlos13565-905 Brazil Department of Materials Engineering Federal University of São Carlos SP São Carlos13565-905 Brazil Department of Metallurgical and Materials Engineering Federal University of Minas Gerais Av. Antônio Carlos 6627 MG Belo Horizonte31270-901 Brazil Department of Chemistry Federal University of Minas Gerais Av. Antônio Carlos 6627 MG Belo Horizonte31270-901 Brazil SP São Carlos13563-120 Brazil

Face-centered cubic (FCC) Cr-Co-Ni multi-principal element alloys are among the toughest materials ever designed. The optimal trade-off between strength and ductility shown by these materials is tied with their deformation evolution. Typically, their plastic deformation starts with dislocation slip, followed by mechanical twinning (i.e., twinning induced plasticity, TWIP) and, as strain levels further increase, phase transformation induced by plasticity (TRIP). This work evaluates the deformation substructure of a highly strained (achieved with high-pressure torsion) Cr40Co30Ni30 (at%) alloy with and without carbon alloying. After processing, the carbon-free alloy developed a typical substructure observed in FCC Medium/High-entropy alloys at later stages of straining, characterized by the presence of nanotwins and HCP lamellae, resulting in a 5.9 GPa hardness. In contrast, carbon addition induced grain refinement and suppression of the TWIP and TRIP effects. Notably, the Cr39.6Co30Ni30C0.4 alloy developed networks of stacking faults with partial dislocations and Lomer-Cottrell locks, which primarily contributed to a stronger hardening capability, resulting in an increased hardness of 7.3 ± 0.8 GPa, 22 % (1.3 GPa) higher than the base alloy. These findings have important implications for better understanding the deformation substructure evolution of FCC multi-principal element alloys and can pave the way forward in regard to the design approaches for carbon-alloying in these materials. © 2025 Elsevier B.V.

关键词： Plastic flow

The S Solubility of Cr and Al Containing Simulated Low-Active Waste Glass

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SSRN 2022年

作者： Smith-Gray, Natalie Stone-Weiss, Nicholas Karcher, Sam Evarts, Jonathan Erickson, Jessica Bussey, John McCloy, John S. Material Science and Engineering Program Washington State University PullmanWA United States School of Mechanical & Materials Engineering Washington State University PullmanWA United States

Borosilicate compositions were designed to explore effects of a fixed amount of Cr, as Cr2O3 or Na2CrO4, and the impact of Al2O3, on sulfur solubility by progressively adding elemental S. The series with Al2O3 has a higher SO3 solubility of ~3.5 mol% while the series without Al2O3 has a SO3 solubility of ~2 mol%. Crystalline Cr2O3 formed only when both Al2O3 and sulfur were present. At the highest S addition, a salt phase always forms, identified as Na2(S,Cr)O4 via spectroscopy, diffraction, and thermal analysis. Magnetic resonance identified no change in the B coordination in either series as S is added, suggesting that the Na is scavenged from other locations, such as the Si sites, to charge compensate sulfate, whether in the glass or in the salt. The Cr precursor identity did not affect the observed overall behavior regarding sulfur, but did impact Cr redox as identified with Raman spectroscopy. © 2022, The Authors. All rights reserved.

关键词： Thermoanalysis

Structural Comparative Study of Zirconium-Zinc Oxide Thin Films on Ceramic and Glass Substrates 1

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Symposium on Advances in Ceramic materials and Processing, 2025, was part of the 154th Annual Meeting and Exhibition, TMS 2025

作者： Bouras, Dikra Fellah, Mamoun Barille, Regis Zerouali, Madiha Hambli, Nawel Merah, Neçar Department of Matter Science Faculty of Science and Technology University Cherif Messadia Souk-Ahras41000 Algeria Mechanical Engineering Department Abbes Laghrour University PO 1252 KhenchelaCP 40004 Algeria Biomaterial Synthesis and Tribology Research Team Abbes Laghrour University PO 1252 KhenchelaCP 40004 Algeria MOLTECH-Anjou Université d’Angers/UMR CNRS 6200 2 Bd Lavoisier Angers49045 France University of 20 Août 1955-Skikda Skikda21000 Algeria University of Souk-Ahras Souk-Ahras Algeria Mechanical Engineering Department King Fahd University of Petroleum and Minerals PO 1180 Dhahran31261 Saudi Arabia Interdisciplinary Research Center for Advanced Materials King Fahd University of Petroleum and Minerals Dhahran31261 Saudi Arabia

ISBN: (数字)9783031806643

ISBN: (纸本)9783031806636

SemiconductorSemiconductor nanostructures have significantly advanced water waste photolysis and hydrogen production through water decomposition. CeramicCeramics materials in thin layers are crucial for protection, gas sensing, and photovoltaics, with thin films exhibiting distinct physicochemical properties compared to bulk materials. The study of nanostructured materials’ physical properties is of great interest to both researchers and industries. This study investigates the influence of substrate type on the structural, morphological, optical, and photocatalytic properties of zirconium-dopedDoped zinc oxide thin layers. Samples were prepared on porous ceramicCeramics and glass substrates under identical conditions, including layer count and dopingDoping ratio. XRD analysis revealed a polycrystalline wurtzite structure in all samples, with grain sizes ranging from 25–43 nm for ceramicCeramics and 19–32 nm for glassZr-doped ZnO/glass substrates. UV–visible absorbance data showed that all Zr-dopedDoped ZnO Zr-doped ZnO/ceramicfilms absorb visible light around 410 nm, with a blue shift observed as zirconium content increased up to 5 wt%. The band gap widened to 2.93 eV for ceramicCeramics substrates. SEM analysis demonstrated that dopingDoping significantly affected ZnO sample morphology. Photocatalytic activities, assessed using orange IIOrange II degradation, showed that zirconium dopingDoping substantially improved performance for samples on ceramicCeramics substrates compared to those on glass. The photolysis mechanism was explored using hole/radical scavengers, revealing that Zr-ZnO networks enhance hydroxyl ion adsorption on the surface. This acts as a trap site, reducing hole/electron pair recombination and thus increasing activity and photodegradationPhotodegradation efficiency. © The Minerals, Metals & materials Society 2025.

关键词： Photolysis