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SSRN 2022年

作者： Khan, Kamruzzaman Jian, Zhe Li, Jonathan Sun, Kai Ahmadi, Elaheh Department of Materials Science and Engineering University of Michigan Ann Arbor United States Department of Electrical Engineering and Computer Science University of Michigan Ann Arbor United States Applied Physics Program University of Michigan Ann Arbor United States

In this study, selective area growth (SAG)s of AlGaN/GaN nanowires (NWs) on miscut N-polar GaN templates were studied and compared with that grown on Ga-polar templates using plasma-assisted molecular beam epitaxy (MBE). The SAG of N-polar AlGaN/GaN NWs demonstrated higher growth rate and more growth selectivity than that of Ga-polar AlGaN/GaN NWs. Additionally, lateral growth rate of N-polar NWs was significantly lower than Ga-polar NWs. Compared to the pyramidal shaped top surfaces of Ga-polar NWs, the N-polar GaN NWs had flat head top surfaces. The combination of higher growth selectivity, larger growth window, negligible lateral growth, and flat head, makes N-polar (Al,Ga)N NWs attractive for a variety of applications including UV LEDs and detectors as well as quantum sensing. © 2022, The Authors. All rights reserved.

关键词： Aluminum gallium nitride

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Highly sensitive spin-flop transition in antiferromagnetic van der Waals material MPS3 (M=Ni and Mn)

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Physical Review materials 2021年第6期5卷 064413-064413页

作者： Rabindra Basnet Aaron Wegner Krishna Pandey Stephen Storment Jin Hu Department of Physics University of Arkansas Fayetteville Arkansas 72701 USA Materials Science and Engineering Program Institute for Nanoscience and Engineering University of Arkansas Fayetteville Arkansas 72701 USA

Recent developments in two-dimensional (2D) magnetism have motivated the search for van der Waals (vdW) magnetic materials to explore magnetic phenomena in the 2D limit. Metal thiophosphates, MPX3, are a class of magnetic vdW materials with antiferromagnetic ordering persisting down to the atomically thin limit. The magnetism in this material family has been found to be highly dependent on the choice of transition metal M. In this work, we have synthesized the intermediate compounds Ni1−xMnxPS3 (0≤x≤1) and investigated their magnetic properties. Our study reveals that the variation of Ni and Mn content in Ni1−xMnxPS3 can efficiently tune the spin-flop transition, likely due to the modulation of the magnetic anisotropy. Such effective tuning offers a promising candidate to engineer 2D magnetism for future device applications.

关键词： Magnetic anisotropy Magnetic order

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Large-Scale Multidisciplinary Design Optimization of an eVTOL Aircraft Using Comprehensive Analysis

Large-Scale Multidisciplinary Design Optimization of an eVTO...

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AIAA SciTech Forum and Exposition, 2023

作者： Sarojini, Darshan Ruh, Marius L. Sperry, Mark Yan, Jiayao Fletcher, Andrew Joshy, Anugrah Jo Scotzniovsky, Luca Ivanov, Alexander Orndorff, Nicholas Gandarillas, Victor Asher, Isaac Chambers, Jeff Gill, Hyunjune Lee, Seongkyu Cheng, Zeyu Rodriguez, Gabriel Zhao, Shuofeng Mi, Chunting Nascenzi, Thomas Cuatt, Timothy Winter, Tyler Guibert, Alexandre Cronk, Ashley Kim, Alicia Meng, Shirley Hwang, John T. Department of Mechanical and Aerospace Engineering University of California San Diego 9500 Gilman Dr La Jolla CA92093 United States Flight Physics Aurora Flight Sciences A Boeing Company 9950 Wakeman Drive ManassasVA20110 United States Engineering Department Aurora Flight Sciences A Boeing Company 9950 Wakeman Drive ManassasVA20110 United States Department of Mechanical and Aerospace Engineering University of California Davis 1 Shields Avenue DavisCA95616 United States Department of Electrical and Computer Engineering San Diego State University 5500 Campanile Dr San Diego92182 United States Research and Development M4 Engineering Inc 4020 Long Beach Blvd # 2 Long BeachCA90807 United States Structural Engineering Department University of California San Diego 9500 Gilman Dr La Jolla CA92093 United States Materials Science and Engineering Program University of California San Diego 9500 Gilman Dr La Jolla CA92093 United States Department of NanoEngineering University of California San Diego 9500 Gilman Dr La Jolla CA92093 United States

ISBN: (数字)9781624106996

ISBN: (纸本)9781624106996

This paper presents a framework under development for enabling large-scale multi-fidelity modeling and optimization of electric vertical takeoff and landing concepts (eVTOL). The key features of the framework are a geometry-centric approach to multidisciplinary design optimization (MDO), a modular functional-form representation of the disciplines involved in aircraft design, and fully automated derivative computations thereby allowing efficient gradient-based optimization. The framework is first presented in a general manner agnostic to the vehicle concept or the physics-based analyses used. The key disciplines involved in the design of eVTOL aircraft and the couplings between the disciplines are described. The framework is then applied to the design of the NASA lift-plus-cruise concept. Low-fidelity solvers of aerodynamics, propulsion, structural estimation, acoustics, powertrain, and battery are coupled together. The optimization considers 108 design variables and 16 constraints. It is shown that MDO considering geometric variables results in a design with lower gross mass than when the geometric variables are not considered. The optimization turnaround time of 30 minutes on a standard workstation demonstrates the capabilities of fully-coupled large-scale MDO using gradient-based optimization. The framework is under development and an open-source version will be released in the near future. © 2023, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.

关键词： Geometry

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Designing the pressure-dependent shear modulus using tessellated granular metamaterials

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Physical Review E 2023年第3期108卷 034901-034901页

作者： Jerry Zhang Dong Wang Weiwei Jin Annie Xia Nidhi Pashine Rebecca Kramer-Bottiglio Mark D. Shattuck Corey S. O'Hern Department of Mechanical Engineering & Materials Science Yale University New Haven Connecticut 06520 USA Benjamin Levich Institute and Physics Department The City College of New York New York New York 10031 USA Department of Physics Yale University New Haven Connecticut 06520 USA Department of Applied Physics Yale University New Haven Connecticut 06520 USA Integrated Graduate Program in Physical and Engineering Biology Yale University New Haven Connecticut 06520 USA

Jammed packings of granular materials display complex mechanical response. For example, the ensemble-averaged shear modulus 〈G〉 increases as a power law in pressure p for static packings of soft spherical particles that can rearrange during compression. We seek to design granular materials with shear moduli that can either increase or decrease with pressure without particle rearrangements even in the large-system limit. To do this, we construct tessellated granular metamaterials by joining multiple particle-filled cells together. We focus on cells that contain a small number of bidisperse disks in two dimensions. We first study the mechanical properties of individual disk-filled cells with three types of boundaries: periodic boundary conditions (PBC), fixed-length walls (FXW), and flexible walls (FLW). Hypostatic jammed packings are found for cells with FLW, but not in cells with PBC and FXW, and they are stabilized by quartic modes of the dynamical matrix. The shear modulus of a single cell depends linearly on p. We find that the slope of the shear modulus with pressure λc<0 for all packings in single cells with PBC where the number of particles per cell N≥6. In contrast, single cells with FXW and FLW can possess λc>0, as well as λc<0, for N≤16. We show that we can force the mechanical properties of multicell granular metamaterials to possess those of single cells by constraining the end points of the outer walls and enforcing an affine shear response. These studies demonstrate that tessellated granular metamaterials provide a platform for the design of soft materials with specified mechanical properties.

关键词： Jamming Granular solids Mechanical metamaterials

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6-Methoxyquinoline Immobilized Nylon Sensor for Monitoring Chloride Concentration in Reinforced Concrete

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SSRN 2023年

作者： Jeong, Hoseong Jung, Byung Jun Kim, Jae Hyun Kim, Kang Su Department of Architectural Engineering and Smart City Interdisciplinary Major Program University of Seoul 163 Seoulsiripdaero Dongdaemun-gu Seoul02504 Korea Republic of Department of Materials Science and Engineering University of Seoul 163 Seoulsiripdaero Dongdaemun-gu Seoul02504 Korea Republic of Department of Architectural Engineering University of Seoul 163 Siripdae-ro Dongdaemun-gu Seoul02504 Korea Republic of

An excess in the threshold concentration of chloride in concrete leads to the initiation of reinforcement corrosion, which in turn results in a reduction in the load-bearing capacity of reinforced concrete(RC) structures. Accordingly, the chloride concentration of RC is periodically investigated via a destructive method, but this process is time-consuming, labor-intensive, and costly. In order to overcome the limitations, this study sought to develop an optical chloride sensor that can be used in structural health monitoring. To this end, nylon was functionalized using formaldehyde and epichlorohydrine, after which 6-methoxy quinoline was covalently immobilized to manufacture a sensor. The developed sensor was found to be capable of measuring chloride concentrations (0~5,000mM) and exhibited rapid responsiveness and reversibility. In addition, the developed sensor also showed a stable response even when exposed to the pH 13.4 environment for three months, and it could detect changes in chloride concentration even inside the mortar. © 2023, The Authors. All rights reserved.

关键词： Reinforced concrete

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Opto-thermoelectric microswimmers

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Light(science & Applications) 2020年第1期9卷 674-685页

作者： Xiaolei Peng Zhihan Chen Pavana Siddhartha Kollipara Yaoran Liu Jie Fang Linhan Lin Yuebing Zheng Materials Science&Engineering Program and Texas Materials Institute The University of Texas at AustinAustinTX 78712USA Walker Department of Mechanical Engineering The University of Texas at AustinAustinTX 78712USA State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentTsinghua UniversityBeijing 100084People’s Republic of China

Inspired by the“run-and-tumble”behaviours of Escherichia coli(***)cells,we develop opto-thermoelectric *** microswimmers are based on dielectric-Au Janus particles driven by a self-sustained electrical field that arises from the asymmetric optothermal response of the *** illumination by a defocused laser beam,the Janus particles exhibit an optically generated temperature gradient along the particle surfaces,leading to an opto-thermoelectrical field that propels the *** further discover that the swimming direction is determined by the particle *** enable navigation of the swimmers,we propose a new optomechanical approach to drive the in-plane rotation of Janus particles under a temperature-gradient-induced electrical field using a focused laser *** the rotation laser beam allows us to position the particles at any desired orientation and thus to actively control the swimming direction with high *** incorporating dark-field optical imaging and a feedback control algorithm,we achieve automated propelling and navigation of the *** optothermoelectric microswimmers could find applications in the study of opto-thermoelectrical coupling in dynamic colloidal systems,active matter,biomedical sensing,and targeted drug delivery.

关键词： rotation illumination beam

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Grain boundary complexion modification for interface stability in garnet based solid-state Li batteries

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Journal of Power Sources 2024年 602卷

作者： Wang, Chih-Chieh Hsu, Wei-Chun Chang, Chia-Yu Ihrig, Martin Thuy Tran, Ngoc Thanh Lin, Shih-kang Windmüller, Anna Tsai, Chih-Long Eichel, Rüdiger-A. Chiu, Kuo-Feng Department of Materials and Optoelectronic Science National Sun Yat-sen University Kaohsiung80424 Taiwan Institute of Energy and Climate Research Forschungszentrum Jülich GmbH Jülich52425 Germany Department of Chemical Engineering National Taiwan University of Science and Technology Taipei City106 Taiwan Research Center National Cheng Kung University Tainan70101 Taiwan Department of Materials Science and Engineering National Cheng Kung University Tainan70101 Taiwan Program on Smart and Sustainable Manufacturing Academy of Innovative Semiconductor and Sustainable Manufacturing National Cheng Kung University Tainan70101 Taiwan Program on Semiconductor Packaging and Testing Academy of Innovative Semiconductor and Sustainable Manufacturing National Cheng Kung University Tainan70101 Taiwan Core Facility Center National Cheng Kung University Tainan70101 Taiwan Department of Materials Science and Engineering Feng Chia University Taichung407 Taiwan

The garnet type solid-state electrolyte (SSE) encounters challenges related to poor interfacial contact with Li metal and dendrite penetration problem. This study addresses these issues by manipulating the surface property of garnet-based LLZTO (Li6.5La3Zr1.6Ta0.4O12) SSE. The manipulation is achieved by varying thickness of Al2O3 atomic layer deposition (ALD), followed by sintering. Research results show that the relative density, ionic conductivity, and hardness of LLZTO are improved while electronic conductivity is reduced due to the formation of multiple complexions at grain boundary (GB). The SSE pellets also demonstrate improved wettability with Li metal, leading to stable galvanostatic Li plating/stripping cycling with low polarization, which allows for batter battery performance than pristine one. The concept of modifying SSE through the grain boundary complexion modification by thin ALD coating for enhancing the dendrite tolerance with better electrochemical properties of SSE may open a new direction for solid state battery research. © 2024 Elsevier B.V.

关键词： Grain boundaries

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Tecnological Tests of the Pegamites Residues Extraction at Alto Dois Irmãos/Pb in Borborema Pegmatitic Province/Bpp

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SSRN 2023年

作者： Silva, Gerson Ferreira de Brum, Irineu Cordeiro, Vinícius Becheleni, Emily Araújo, Defsson Federal University of Rio Grande do Sul – UFRGS Postgraduate Program in Mining Engineering Metallurgical and of Materials Brazil Federal University of Rio Grande do Sul – UFRGS Department of Metallurgical Engineering Postgraduate Program in Mining Engineering Metallurgical and Materials Brazil Federal University of Campina Grande – UFCG Academic Unity of Mining and Geology Brazil Federal University of Vales do Jequitinhonha e Mucuri – UFVJM Engineering Institute Science and Technology Brazil Federal University of Campina Grande – IFPB Federal Institute of Science Education and Technology of Paraíba Campus Picuí Brazil

The Borborema Pegmatitic Province – BPP situated between Paraiba and Rio Grande do Norte states in Brazilian northeast presents several pegmatites occurrences. In the region of the county of Pedra Lavrada – PB, are observed various mineral occurrences where the pegmatites have been explored with prominence at Alto Dois Irmãos-PB pegmatite, in what quartz, feldspar and mica are extracted. Because an existence of a complex mineralogy of the pegmatites, the understanding about mineral constituent is fundamental to define its industrial employment and also to implement improvements in beneficiation process. The proposal of this research line is the detailed characterization and proof that part of the ore (quartz) considered sterile, presents low poisoning (Fe2O3) and high silica (SiO2) content, to enable its industrial use mainly to nobler purposes. Also will be fundamental to minimize the environmental impact and decrease the grinding energetic consume. Besides that, the obtained results of this research will be used in a future work, as inputs in simulation stage, aiming to optimize the researched beneficiation unity grinding process. To the pegmatite characterization were done density determination tests, mineralogical identification by X-ray diffraction (XRD), chemical analysis by fluorescents X-rays and morphological analysis by scanning electron microscopy (SEM/EDS). Then were done tests to Work Index (WI) calculous. The sterile (quartz extraction) from pegmatite mining in Pedra Lavrada/PB presented medium density of 2,66g/cm3, majority chemical composition of silicon and oxygen and quartz as the mainly mineralogical stage, through X-ray diffractograms and scanning electron microscopy images, what indicates that this material has high purity. The Work Index (WI) was 15,9 kwh/t, showing that this material presents in the pegmatite can be consider resistant to breaking in grinding process. © 2023, The Authors. All rights reserved.

关键词： Quartz

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Terahertz Time-Domain Imaging for Radiotherapy Treatment Monitoring in Pancreatic Ductal Adenocarcinoma

Terahertz Time-Domain Imaging for Radiotherapy Treatment Mon...

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Conference on Lasers and Electro-Optics (CLEO)

作者： Debamitra Chakraborty Bradley N. Mills Jing Cheng Ivan Komissarov Scott Gerber Roman Sobolewski Materials Science Graduate Program University of Rochester Rochester New York Laboratory for Laser Energetics University of Rochester Rochester New York Department of Surgery University of Rochester Medical Center Rochester New York Department of Electrical and Computer Engineering University of Rochester Rochester New York

ISBN: (纸本)9798350369311

Terahertz time-domain imaging was performed of stereotactic body radiotherapy-treated murine pancreatic ductal adenocarcinoma (PDAC) with a high spatial resolution. To generate 2D maps of the tissue samples, the refractive index and absorption coefficient were used as imaging markers extracted with the maximum a-posteriori probability (MAP) estimation algorithm. The results were then compared with the terahertz maps of untreated murine PDAC tissue samples and demonstrated that terahertz imaging can probe physical changes with high sensitivity in the tissue post treatment.

关键词： Maximum a posteriori estimation Terahertz wave imaging Laser theory Sensitivity Refractive index Radiation therapy Time-domain analysis Spatial resolution Probes Monitoring

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Multimodal Sensing Algorithm Using Thermoelectric Dynamics for Self-Powered Skin-Like Sensory Devices

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SSRN 2023年

作者： Lee, Hyeju Baek, Jong Jin Oh, Jin Young Lee, Tae Il Department of Materials Science and Engineering Gachon University Gyeonggi Seong-Nam13120 Korea Republic of Advanced Development Team Ilji Tech Co. Ltd. Sinsang-ri Jillyang-eup Gyeongsangbuk-do Gyeongsan-si 12103 Korea Republic of Department of Chemical Engineering Integrated Engineering Program Kyung Hee University Yongin17104 Korea Republic of

In the rapidly evolving field of electronic skins (e-skins), the development of self-powered sensors has emerged as a promising solution to providing continuous and reliable power sources for embedded sensors. This study introduces a novel approach that incorporates spike-shaped nickel (Ni) microparticles into a styrene-ethylene-butylene-styrene (SEBS) matrix, resulting in a thermoelectric material that functions as both an energy harvester and a pressure sensor, and a multimodal sensing algorithm designed to mitigate pressure sensing errors arising from temperature fluctuations in the thermoelectric self-powered pressure sensor. The Ni-SEBS composite, with a sensing mechanism that identifies changes in the Ni particle percolation state induced by compressive strain, exhibited a high sensitivity of 0.6234 kPa-1. Based on this composite, a dual-channel self-powered sensor was fabricated using the proposed algorithm and attached to the skin;the sensor successfully detected various forms of external pressure applied to the skin without errors due to temperature changes. © 2023, The Authors. All rights reserved.

关键词： Pressure sensors

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