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Investigating the influence of environmental conditioning on epoxy resins at quasistatic and high strain rates for material operating limit 36

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Investigating the influence of environmental conditioning on...

36th Technical Conference of the American Society for Composites 2021: Composites Ingenuity Taking on Challenges in Environment-Energy-Economy, ASC 2021

作者： Doshi, Sagar M. Manoharan, Nithinkumar Haque, Bazle Z. Deitzel, Joseph M. Gillespie, John W. Center for Composite Materials University of Delaware NewarkDE19716 United States Department of Materials Science and Engineering Department of Mechanical Engineering Department of Civil and Environmental Engineering Department of Computer and Electrical Engineering University of Delaware NewarkDE19716 United States

ISBN: (纸本)9781713837596

Epoxy resin-based composite panels used for armors may be subjected to a wide range of operating temperatures (-55℃ to 76℃) and high strain rates on the order of 103-104 s-1. Over the life cycle, various environmental factors also affect the resin properties and hence influence the performance of the composites. Therefore, it is critical to determine the stress-strain behavior of the epoxy resin over a wide range of strain rates and temperatures for accurate multi-scale modeling of composites and to investigate the influence of environmental aging on the resin properties. Additionally, the characterization of key mechanical properties such as yield stress, modulus, and energy absorption (i.e. area under the stress-strain curve) at varying temperatures and moisture can provide critical data to calculate the material operating limits. In this study, we characterize mechanical properties of neat epoxy resin, SC-15 (currently used in structural armor) and RDL-RDC using uniaxial compression testing. RDL-RDC, developed by Huntsman Corporation, has a glass transition temperature of ~ 120℃, compared to ~ 85℃ of SC-15. A split Hopkinson pressure bar is used for high strain rate testing. Quasistatic testing is conducted using a screw-driven testing machine (Instron 4484) at 10-3 s-1 and 10-1 s-1 strain rates and varying temperatures. The yield stress is fit to a modified Eyring model over the varying strain rates at room temperature. For rapid investigation of resistance to environmental aging, accelerated aging tests are conducted by immersing the specimens in 100℃ water for 48 hours. Specimens are conditioned in an environmental chamber at 76 ℃ and 88% RH until they reach equilibrium. Tests are then conducted at five different temperatures from 0℃ to 95℃, and key mechanical properties are then plotted vs. temperature. The results presented are an important step towards developing a methodology to identify environmental operating conditions for composite ground vehicle appli

关键词： Epoxy resins

Inorganic nanoparticles for photothermal treatment of cancer

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Journal of materials Chemistry B 2024年第15期12卷 3569-3593页

作者： Thirumurugan, Senthilkumar Ramanathan, Susaritha Muthiah, Kayalvizhi Samuvel Lin, Yu-Chien Hsiao, Michael Dhawan, Udesh Wang, An-Ni Liu, Wai-Ching Liu, Xinke Liao, Mei-Yi Chung, Ren-Jei No. 1 Sec. 3 Zhongxiao E. Rd Taipei10608 Taiwan School of Materials Science and Engineering Nanyang Technological University 50 Nanyang Avenue Singapore639798 Singapore Genomics Research Center Academia Sinica Taipei115 Taiwan Department and Graduate Institute of Veterinary Medicine School of Veterinary Medicine National Taiwan University Taipei10617 Taiwan Centre for the Cellular Microenvironment Division of Biomedical Engineering James Watt School of Engineering Mazumdar-Shaw Advanced Research Centre University of Glasgow GlasgowG116EW United Kingdom Scrona AG Grubenstrasse 9 Zürich8045 Switzerland Faculty of Science and Technology Technological and Higher Education Institute of Hong Kong New Territories Hong Kong999077 Hong Kong College of Materials Science and Engineering Chinese Engineering and Research Institute of Microelectronics Shenzhen University Shenzhen518060 China Department of Electrical and Computer Engineering National University of Singapore Singapore117583 Singapore Department of Applied Chemistry National Pingtung University Pingtung90003 Taiwan Taipei106 Taiwan

In recent years, inorganic nanoparticles (NPs) have attracted increasing attention as potential theranostic agents in the field of oncology. Photothermal therapy (PTT) is a minimally invasive technique that uses nanoparticles to produce heat from light to kill cancer cells. PTT requires two essential elements: a photothermal agent (PTA) and near-infrared (NIR) radiation. The role of PTAs is to absorb NIR, which subsequently triggers hyperthermia within cancer cells. By raising the temperature in the tumor microenvironment (TME), PTT causes damage to the cancer cells. Nanoparticles (NPs) are instrumental in PTT given that they facilitate the passive and active targeting of the PTA to the TME, making them crucial for the effectiveness of the treatment. In addition, specific targeting can be achieved through their enhanced permeation and retention effect. Thus, owing to their significant advantages, such as altering the morphology and surface characteristics of nanocarriers comprised of PTA, NPs have been exploited to facilitate tumor regression significantly. This review highlights the properties of PTAs, the mechanism of PTT, and the results obtained from the improved curative efficacy of PTT by utilizing NPs platforms. © 2024 The Royal Society of Chemistry

关键词： Cancer cells

Temperature Dependent Low-Frequency Noise Characteristics of NiOx/β-Ga2O3 p-n Heterojunction Diodes

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arXiv 2023年

作者： Ghosh, Subhajit Mudiyanselage, Dinusha Herath Kargar, Fariborz Zhao, Yuji Fu, Houqiang Balandin, Alexander A. Department of Electrical and Computer Engineering University of California RiversideCA92521 United States School of Electrical Computer and Energy Engineering Arizona State University TempeAZ85287 United States Department of Electrical and Computer Engineering Rice University HoustonTX77005 United States Department of Materials Science and Engineering University of California Los AngelesCA90095 United States

We report on the temperature dependence of the low-frequency electronic noise in NiOx/βGa2O3 p-n heterojunction diodes. The noise spectral density is of the 1/f-type near room temperature but shows signatures of Lorentzian components at elevated temperatures and at higher current levels (f is the frequency). We observed an intriguing non-monotonic dependence of the noise on temperature near T = 380 K. The Raman spectroscopy of the device structure suggests material changes, which results in reduced noise above this temperature. The normalized noise spectral density in such diodes was determined to be on the order of 10–14 cm2/Hz (f = 10 Hz) at 0.1 A/cm2 current density. In terms of the noise level, NiOx/β-Ga2O3 p-n diodes occupy an intermediate position among devices of various designs implemented with different ultra-wide-bandgap semiconductors. The obtained results are important for understanding the electronic properties of NiOx/β-Ga2O3 heterojunctions and contribute to the development of noise spectroscopy as the quality assessment tool for new electronic materials and device technologies. Copyright © 2023, The Authors. All rights reserved.

关键词： Electronic properties

Chiral, Topological, and Knotted Colloids in Liquid Crystals

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arXiv 2024年

作者： Yuan, Ye Smalyukh, Ivan I. Hiroshima University Hiroshima Higashi-Hiroshima739-8526 Japan Department of Physics Department of Electrical Computer and Energy Engineering Materials Science and Engineering Program Soft Materials Research Center University of Colorado BoulderCO80309 United States Renewable and Sustainable Energy Institute National Renewable Energy Laboratory University of Colorado BoulderCO80309 United States

The geometric shape, symmetry, and topology of colloidal particles often allow for controlling colloidal phase behavior and physical properties of these soft matter systems. In liquid crystalline dispersions, colloidal particles with low symmetry and nontrivial topology of surface confinement are of particular interest, including surfaces shaped as handlebodies, spirals, knots, multi-component links, and so on. These types of colloidal surfaces induce topologically nontrivial three-dimensional director field configurations and topological defects. Director switching by electric fields, laser tweezing of defects, and local photo-thermal melting of the liquid crystal host medium promote transformations among many stable and metastable particle-induced director configurations that can be revealed by means of direct label-free three-dimensional nonlinear optical imaging. The interplay between topologies of colloidal surfaces, director fields, and defects is found to show a number of unexpected features, such as knotting and linking of line defects, often uniquely arising from the nonpolar nature of the nematic director field. This review article highlights fascinating examples of new physical behavior arising from the interplay of nematic molecular order and both chiral symmetry and topology of colloidal inclusions within the nematic host. Furthermore, the article concludes with a brief discussion of how these findings may lay the groundwork for new types of topology-dictated self-assembly in soft condensed matter leading to novel mesostructured composite materials, as well as for experimental insights into the pure-math aspects of low-dimensional topology. © 2024, CC BY.

关键词： Crystal symmetry

Convergence of energy-based learning in linear resistive networks

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arXiv 2025年

作者： Huijzer, Anne-Men Chaffey, Thomas Besselink, Bart van Waarde, Henk J. Bernoulli Institute for Mathematics Computer Science and Artificial Intelligence University of Groningen Groningen Netherlands CogniGron - Groningen Cognitive Systems and Materials Center Netherlands Control Group Department of Engineering University of Cambridge United Kingdom School of Electrical and Computer Engineering University of Sydney Australia

Energy-based learning algorithms are alternatives to backpropagation and are well-suited to distributed implementations in analog electronic devices. However, a rigorous theory of convergence is lacking. We make a first step in this direction by analysing a particular energy-based learning algorithm, Contrastive Learning, applied to a network of linear adjustable resistors. It is shown that, in this setup, Contrastive Learning is equivalent to projected gradient descent on a convex function, for any step size, giving a guarantee of convergence for the *** Codes 65K10, 68T05, 93B30, 93D99 © 2025, CC BY-SA.

关键词： Contrastive Learning

A Modular UAV Hardware Platform for Aerial Indoor Navigation Research and Development

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A Modular UAV Hardware Platform for Aerial Indoor Navigation...

International Conference on Unmanned Aircraft Systems (ICUAS)

作者： Kyriakos M. Deliparaschos Savvas G. Loizou Argyrios C. Zolotas Electrical and Computer Engineering and Informatics Department Cyprus University of Technology Limassol Cyprusk Department of Mechanical Engineering and Materials Science and Engineering Cyprus University of Technology Limassol Cyprus Centre for Autonomous and Cyber-Physical Systems SATM Cranfield University Cranfield UK

ISBN: (数字)9798350357882

ISBN: (纸本)9798350357899

This study introduces a specialised hardware plat-form designed for indoor navigation, featuring a quadrotor equipped with either a NVIDIA Jetson Nano or a Z-turn Zynq onboard computer. The onboard computer communicates via ROS2 with the flight controller, the Inertial Measurement Unit (IMU), Ultra-WideBand (UWB) localisation system, stereo camera, Light Detection and Ranging (LiDAR), and ultrasonic sensors. The focus is on creating a low-cost modular Unmanned Aerial Vehicle (UAV) system adaptable to various indoor navigation applications. The modular design encompasses different onboard computer platforms and sensor configurations, allowing for easy adaptation to research experiment setups. The objective is to facilitate the transition from simulated and simplified laboratory experiments to deploying aerial robots in challenging real-world conditions. The paper explores the hardware architecture and Robot Operating System 2 (ROS2)-based communication system of the UAV and provides a weight analysis and power estimation.

关键词： Measurement units Indoor navigation Operating systems Autonomous aerial vehicles Hardware Sensor systems Sensors

A Preliminary Study on the Collaborative Playing Piano Automatic with Deep Learning

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A Preliminary Study on the Collaborative Playing Piano Autom...

IEEE International Conference on Consumer Electronics-Taiwan (ICCE-TW)

作者： Varinya Phanichraksaphong Karuna Yampray Department of Electronic Engineering International Graduate Program of Electrical Engineering and Computer Science National Taipei University of Technology Taipei Taiwan College of Creative Design and Entertainment Technology Dhurakij Pundit University Bangkok Thailand

ISBN: (数字)9798350386844

ISBN: (纸本)9798350386851

A great number of deep learning-based models have been recently proposed for automatic piano classification. In this paper, we describe our contribution to the challenge of automatic piano classification when the performer performs at the concert or stage. Among these models in deep learning, we use init-1D-WaveNet and init-2D-MLNet for comparison the accuracy in the piano beginning level of the Christmas song (Jingle bells). Our experimental results show that the assessment using the init-2D-MLNet still achieve high accuracy of 87.5%.

关键词： Deep learning Accuracy Instruments Collaboration Consumer electronics

Recent Advancements in Nanophotonics for Optofluidics

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arXiv 2024年

作者： Yang, Sen Hong, Chuchuan Zhu, Guodong Anyika, Theodore Hong, Ikjun Ndukaife, Justus C. Institute of Physics Chinese Academy of Sciences Beijing National Laboratory for Condensed Matter Physics Beijing100190 China Department of Chemistry Department of Materials Science and Engineering Northwestern University EvanstonIL60208 United States Department of Electrical and Computer Engineering Vanderbilt University NashvilleTN37235 United States Department of Mechanical Engineering Vanderbilt University NashvilleTN37235 United States Interdisciplinary Materials Science Program Vanderbilt University NashvilleTN37240 United States

Optofluidics is dedicated to achieving integrated control of particle and fluid motion, particularly on the micrometer scale, by utilizing light to direct fluid flow and particle motion. The field has seen significant growth recently, driven by the concerted efforts of researchers across various scientific disciplines, notably for its successful applications in biomedical science. In this review, we explore a range of optofluidic architectures developed over the past decade, with a primary focus on mechanisms for precise control of micro and nanoscale biological objects and their applications in sensing. Regarding nanoparticle manipulation, we delve into mechanisms based on optical nanotweezers using nanolocalized light fields and light-based hybrid effects with dramatically improved performance and capabilities. In the context of sensing, we emphasize those works that used optofluidics to aggregate molecules or particles to promote sensing and detection. Additionally, we highlight emerging research directions, encompassing both fundamental principles and practical applications in the field. Copyright © 2024, The Authors. All rights reserved.

关键词： Flow of fluids

Design of Semiconductor Laser Drive Circuit Based on STM32

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Design of Semiconductor Laser Drive Circuit Based on STM32

IEEE International Conference on Power and Energy Applications (ICPEA)

作者： Shangkun Wang Junchao Zhang Xiaofeng Yang Shijia Guo Huanshuai Yan Bingshe Xu College of Electrical and Power Engineering Taiyuan University of Technology Taiyuan China Department of Computer Engineering Shanxi Vocational University of Engineering Science and Technical College Yuci China Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering Taiyuan China

ISBN: (数字)9798350356113

ISBN: (纸本)9798350356120

A circuit using STM32 chip as the main control is designed to address the issue of semiconductor laser performance being easily affected by injection current and operating temperature. It can achieve high-precision and high stability constant current drive and constant temperature control, and has complete protection functions. The system adopts LT3080 The AD5160, TS5A3159 chips and sampling resistors have been designed with a constant current negative feedback circuit; Design a constant voltage limiting module using LM317 chip to ensure that the forward voltage of the semiconductor laser does not exceed the rated maximum value, and the slow start module slowly increases the current to the set value; The electrostatic protection circuit effectively avoids the damage of high-voltage static electricity and surge current to the laser; Design a temperature sampling module with ADN8834 as the core, and use incremental digital PID technology to control the heating or cooling of TEC. The experimental results show that this driving circuit can continuously adjust the current of the semiconductor laser, with a range of 0 to 100 mA. The current regulation accuracy has reached 0.01mA, and the stability has reached 0.02%; The temperature control accuracy within 10–40 °C is 0.01 °C, and the stability can reach 0.12%.

关键词： Accuracy Semiconductor lasers Laser feedback Laser stability Circuit stability Voltage control Protection Laser applications Surges Thermal stability