检索结果-内蒙古大学图书馆

Frontiers in Education (FIE) Conference

作者： Eric Jankowski Krishna Pakala Sara Hagenah Micron School of Materials Science and Engineering Boise State University Boise USA Mechanical and Biomedical Engineering Boise State University Boise USA Curriculum Instruction & Foundational Studies Boise State University Boise USA

Student persistence in STEM programs is linked to student sense of belonging and identification with their major or profession. Lack of professional identification and lack of belonging exacerbate departures of Black, Latinx, Native, and Female students from STEM programs, for whom exclusionary department cultures and biased policies have amplified impact. This workshop provides an overview of the science and craft of storytelling which has been developed with The Story Collider.

关键词：

来源：评论

学校读者我要写书评

暂无评论

A Hybrid System Combining Direct Contact Membrane Distillation (Dcmd) and Electrochemical Switched Ion Exchange (Esix) for Efficient Lithium Recovery from Simulated Brine

SSRN

引用

SSRN 2023年

作者： Gulied, Mona Zavahir, Sifani Elmakki, Tasneem Park, Hyunwoong Shon, Hokyong Han, Dong Suk Center for Advanced Materials Qatar University Doha Qatar Materials Science and Technology Program College of Arts and Science Qatar University Doha Qatar School of Energy Engineering Kyungpook National University Daegu41566 Korea Republic of ARC Research Hub for Nutrients in a Circular Economy Center for Technology in Water and Wastewater School of Civil and Environmental Engineering Faculty of Engineering and IT University of Technology SydneyNSW2007 Australia Department of Chemical Engineering College of Engineering Qatar University Doha Qatar

Recovering valuable elements such as lithium (Li) from seawater reverse osmosis (SWRO) brine is crucial for building a sustainable economy due to its high storage density, making it an ideal material for energy storage. In this study, a novel hybrid system that combines direct contact membrane distillation (DCMD) and electrochemical switched ion exchange (ESIX) was designed to achieve simultaneous SWRO brine enrichment and Li recovery. The DCMD process concentrated the SWRO brine using electrospun nanofiber membranes (ENMs) made of polyvinylidene fluoride (PVDF), with the incorporation of reduced graphene oxide (rGO) nanoparticles enhancing the morphological, thermal, and mechanical stability of the PVDF ENMs. The water contact angle (WCA) of the 1-rGO/PVDF ENM was 142.08°, indicating an improved hydrophobic property that resulted in the recovery of 12% freshwater from simulated SWRO brine and a 2.4-fold increase in Li+ concentration. The 1-rGO/PVDF ENM exhibited stable performance, with an 11% reduction in WCA after 15 hours of brine concentration. In the hybrid operation, a Li-selective LiAlO2 electrode, coupled with an activated carbon counter electrode, demonstrated remarkable Li recovery for Li capture solutions enriched by the rGO-PVDF membrane in the DCMD step. Compared to the Li concentration in the DCMD feed, sequential Li capture and release cycles recovered 91.8% of Li, highlighting the critical role of the hybrid mode operation in concentrating Li from simulated brine solutions. © 2023, The Authors. All rights reserved.

关键词： Hybrid systems

来源：评论

学校读者我要写书评

暂无评论

Dual-Module Ultrawide Dynamic-Range High-Power Rectifier for WPT Systems

引用

Energies 2024年第11期17卷 2707页

作者： Yu, Xiaochen Zhang, Jinyao Liu, Minzhang Yang, Xiantao Huang, Yi Yen, Ta-Jen Zhou, Jiafeng Department of Electrical Engineering and Electronics University of Liverpool LiverpoolL69 3GJ United Kingdom International Intercollegiate Ph.D. Program National Tsing Hua University Hsinchu300044 Taiwan Department of Materials Science and Engineering National Tsing Hua University Hsinchu300044 Taiwan

Rectifier plays a pivotal role in wireless power transfer systems. While numerous studies have concentrated on enhancing efficiency and bandwidth at specific high-power levels, practical scenarios often involve unpredictable power inputs. Consequently, a distinct need arises for a rectifier that demonstrates superior efficiency across a broad range of input power levels. This paper introduces a high-power RF-to-DC rectifier designed for WPT applications, featuring an ultrawide dynamic range of input power. The rectification process leverages a GaN (gallium nitride) high electron mobility transistor (HEMT) to efficiently handle high power levels up to 12.6 W. The matching circuit was designed to ensure that the rectifier will operate in class-F mode. A Schottky diode is incorporated into the design for relatively lower-power rectification. Seamless switching between the rectification modes of the two circuits is accomplished through the integration of a circulator. The proposed rectifier exhibits a 27.5 dB dynamic range, achieving an efficiency exceeding 55% at 2.4 GHz. Substantial improvement in power handling and dynamic range over traditional rectifiers is demonstrated. © 2024 by the authors.

关键词： Gallium nitride

来源：评论

学校读者我要写书评

暂无评论

Photonic Crystals with Split Ring Unit Cells for Subwavelength Light Confinement

Photonic Crystals with Split Ring Unit Cells for Subwaveleng...

引用

Conference on Lasers and Electro-Optics (CLEO)

作者： Kellen P. Arnold Sami I. Halimi Joshua A. Allen Shuren Hu Sharon M. Weiss Interdisciplinary Materials Science Program Vanderbilt University Nashville TN USA Department of Electrical Engineering and Computer Science Vanderbilt University Nashville TN USA

We report a split ring photonic crystal that demonstrates an order of magnitude larger peak energy density compared to traditional photonic crystals. The split ring offers highly focused optical energy in an accessibl... 详细信息

ISBN: (数字)9781957171050

ISBN: (纸本)9781665466660

关键词： Optical resonators Photonic crystals Ring lasers Electrooptical waveguides Photonics

来源：评论

学校读者我要写书评

暂无评论

Impact of Quantum Well Thickness on Efficiency Loss in InGaN/GaN LEDs: Challenges for Thin-Well Designs

arXiv

引用

arXiv 2025年

作者： Li, Xuefeng Pant, Nick Rahman, Sheikh Ifatur Armitage, Rob Rajan, Siddharth Kioupakis, Emmanouil Feezell, Daniel University of New Mexico AlbuquerqueNM87106 United States Department of Materials Science & Engineering University of Michigan Ann ArborMI48109 United States Applied Physics Program University of Michigan Ann ArborMI48109 United States Department of Electrical and Computer Engineering The Ohio State University ColumbusOH43210 United States Lumileds LLC San JoseCA95131 United States Department of Materials Science and Engineering The Ohio State University ColumbusOH43210 United States

We investigate the impact of quantum well (QW) thickness on efficiency loss in c-plane InGaN/GaN LEDs using a small-signal electroluminescence (SSEL) technique. Multiple mechanisms related to efficiency loss are independently examined, including injection efficiency, carrier density vs. current density relationship, phase space filling (PSF), quantum confined stark effect (QCSE), and Coulomb enhancement. An optimal QW thickness of around 2.7 nm in these InGaN/GaN LEDs was determined for quantum wells having constant In composition. Despite better control of deep-level defects and lower carrier density at a given current density, LEDs with thin QWs still suffer from an imbalance of enhancement effects on the radiative and intrinsic Auger-Meitner recombination coefficients. The imbalance of enhancement effects results in a decline in internal quantum efficiency (IQE) and radiative efficiency with decreasing QW thickness at low current density in LEDs with QW thicknesses below 2.7 nm. We also investigate how LED modulation bandwidth varies with quantum well thickness, identifying the key trends and their implications for device performance. Copyright © 2025, The Authors. All rights reserved.

关键词： Semiconductor quantum wells

来源：评论

学校读者我要写书评

暂无评论

Uncertainty Quantification and Propagation for Multiscale materials Systems with Agglomeration and Structural Anomalies

SSRN

引用

SSRN 2024年

作者： Comlek, Yigitcan Mojumder, Satyajit van Beek, Anton Prabhune, Prajakta Ciampaglia, Alberto Apley, Daniel W. Brinson, L. Catherine Liu, Wing Kam Chen, Wei Department of Mechanical Engineering Northwestern University Evanston United States Theoretical and Applied Mechanics Program Northwestern University Evanston United States School of Mechanical and Materials Engineering University College Dublin Dublin Ireland Thomas Lord Department of Mechanical Engineering and Materials Science Duke University Durham United States Department of Mechanical and Aerospace Engineering Politecnico di Torino Turin Italy Department of Industrial Engineering and Management Sciences Northwestern University Evanston United States

Advancements in manufacturing technologies have enabled material system design optimization at multiple length scales. However, the microstructural anomalies and uncertainties present at each scale have not been considered comprehensively enough for systems to be robust to manufacturing variations. Consequently, considering anomalies at various length scales of the material’s structure and understanding their effects on a part’s response are crucial for designing engineered parts that are robust to various sources of uncertainty. In this work, an efficient bottom-up hierarchical uncertainty quantification and propagation framework bridging multiple scales to establish a design allowable range for the material system at the part-scale is presented. We demonstrate our framework on an additively manufactured polymer nanocomposite material system that is subject to anomalies at different length scales that impact the material properties. Specifically, agglomeration defects formed due to attractive forces between nanoparticles at the microscale and structural variabilities caused by the voids resulting from different processing conditions at the mesoscale are considered. The introduced hierarchical sampling framework combines (i) an innovative microstructure image characterization and reconstruction, (ii) a mechanistic reduced-order model that enables fast property predictions for high-dimensional microstructural design spaces, and (iii) efficient uncertainty quantification and propagation through Copula-based sampling across multiple length scales to reduce the sampling budget by 95%. Through validation of our method, we demonstrate the importance of considering the effects of process-induced microstructure features on the performance of a part. © 2024, The Authors. All rights reserved.

关键词： Microstructure

来源：评论

学校读者我要写书评

暂无评论

Ultrasound for the degradation of endocrine disrupting compounds in aqueous solution: A review on mechanisms, influence of operating parameters and cost estimation

引用

Chemosphere 2024年 349卷 140864页

作者： Ghosh, Saptarshi Sahu, Manoranjan Aerosol and Nanoparticle Technology Laboratory Environmental Science and Engineering Department Indian Institute of Technology Bombay Mumbai400076 India Inter-Disciplinary Program in Climate Studies Indian Institute of Technology Bombay Mumbai400076 India Centre for Machine Intelligence and Data Science Indian Institute of Technology Bombay Mumbai400076 India

Availability of drinking water is one of the basic humanitarian goals but remains as a grand challenge that the world is facing today. Currently, water bodies are contaminated not only with conventional pollutants but also with numerous recalcitrant pollutants, such as PPCPs, endocrine disrupting compounds, etc. These emerging pollutants require special attention because of their toxicity to living organisms, bio-resistant and can sustain even after primary and secondary treatments of wastewater. Among different treatment technologies, sonolysis is found to be an innovative and promising technique for the treatment of emerging pollutants present in aqueous solution. Sonolysis is the use of ultrasound to enhance or alter chemical reactions by the formation of free radicals and shock waves which ultimately helps in degradation of pollutants. This review summarizes several studies in the sonochemical literature, including mechanisms of sonochemical process, physical and chemical effects of ultrasound, and the influence of several process variables such as ultrasound frequency, power density, temperature and pH of the medium on degradation performance for endocrine disrupting compounds. In addition, this review highlighted techno-economic perspectives focusing on the total cost required for translating the ultrasound-based processes on a large scale. Overall, the objective of this study is to exhibit a critical review of information available in the literature to encourage and promote future research on sonolysis for the degradation of Endocrine Disrupting Compounds (EDCs). © 2023 Elsevier Ltd

关键词： Wastewater treatment

来源：评论

学校读者我要写书评

暂无评论

Optical and Mechanical Properties of Rutile TiO2 Subjected to AC Flash Processing

SSRN

引用

SSRN 2024年

作者： Masuda, Hiroshi Tokunaga, Tomoharu Yamamoto, Takahisa Yoshida, Hidehiro Department of Materials Science and Engineering School of Engineering The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo113-8656 Japan Department of Materials Design Innovation Engineering School of Engineering Nagoya University Furo-cho Chikusa-ku Nagoya464-8603 Japan Next Generation Zirconia Social Cooperation Program Institute of Engineering Innovation The University of Tokyo 2-11-16 Yayoi Bunkyo-ku Tokyo113-8656 Japan

Unusual physical properties associated with lattice defects induced by flash sintering and processing of oxide ceramics have attracted attentions. In this study, optical and mechanical properties of undoped and polycrystalline rutile TiO2 subjected to alternating current (AC) flash processing were characterized through diffuse reflectance spectroscopy and nanoindentation experiments at room temperature. The flashed sample exhibited substantial optical blackening and elastic softening but negligible changes in the hardness and crystal structure. The elastic softening demonstrated a significant rate dependence (i.e., elastic moduli decreased with testing rate) indicating anelasticity, which was possibly caused by stress-induced reordering of point defect dipoles induced by AC flash processing. This anelasticity suggests that pronounced ionic mobility is obtained by flash processing even in undoped systems, which can potentially be extended to a general understanding of mass transport phenomena in transient metal oxides in strong electric fields. © 2024, The Authors. All rights reserved.

关键词： Nanoindentation

来源：评论

学校读者我要写书评

暂无评论

Bridging scales with Machine Learning: From first principles statistical mechanics to continuum phase field computations to study order-disorder transitions in LixCoO2

arXiv

引用

arXiv 2023年

作者： Teichert, G.H. Das, S. Shojaei, M. Faghih Holber, J. Mueller, T. Hung, L. Gavini, V. Garikipati, K. Department of Mechanical Engineering University of Michigan United States Toyota Research Institute Los AltosCA United States Department of Materials Science & Engineering University of Michigan United States Department of Mathematics University of Michigan United States Michigan Institute for Computational Discovery & Engineering University of Michigan United States Applied Physics Program University of Michigan United States Materials Science & Engineering Johns Hopkins University United States

LixTMO2 (TM=Ni, Co, Mn) forms an important family of cathode materials for Li-ion batteries, whose performance is strongly governed by Li composition-dependent crystal structure and phase stability. Here, we use LixCoO2 (LCO) as a model system to benchmark a machine learning-enabled framework for bridging scales in materials physics. We focus on two scales: (a) assemblies of thousands of atoms described by density functional theory-informed statistical mechanics, and (b) continuum phase field models to study the dynamics of order-disorder transitions in LCO. Central to the scale bridging is the rigorous, quantitatively accurate, representation of the free energy density and chemical potentials of this material system by coarsegraining formation energies for specific atomic configurations. We develop active learning workflows to train recently developed integrable deep neural networks for such high-dimensional free energy density and chemical potential functions. The resulting, first principles-informed, machine learning-enabled, phase-field computations allow us to study LCO cathodes’ phase evolution in terms of temperature, morphology, charge cycling and particle size. © 2023, CC BY-NC-SA.

关键词： Cathodes

来源：评论

学校读者我要写书评

暂无评论

Strain-tuning of domain walls in multilayer graphene probed in the quantum Hall regime

引用

Physical Review B 2022年第8期105卷 L081408-L081408页

作者： Paul Anderson Yifan Huang Yuanjun Fan Sara Qubbaj Sinisa Coh Qin Zhou Claudia Ojeda-Aristizabal Department of Physics and Astronomy California State University Long Beach Long Beach California 90840 USA Department of Mechanical and Materials Engineering University of Nebraska Lincoln Nebraska 68588-0526 USA Department of Mechanical Engineering and Materials Science and Engineering Program University of California Riverside Riverside California 92521 USA

Domain walls, topological defects that define the frontier between regions of different stacking order in multilayer graphene, have proved to host exciting physics. The ability to tune these topological defects in situ in an electronic transport experiment brings a wealth of possibilities in terms of fundamental understanding of domain walls as well as for electronic applications. Here, we demonstrate, through a MEMS (microelectromechanical system) actuator and magnetoresistance measurements, the effect of domain walls in multilayer graphene quantum Hall effect. Reversible and controlled uniaxial strain triggers the topological defects, manifested as addtional quantum Hall effect plateaus as well as a discrete and reversible modulation of the current across the device. Our findings are supported by theoretical calculations and constitute indication of the in situ tuning of topological defects in multilayer graphene probed through electronic transport, opening the way for the use of reversible topological defects in electronic applications.

关键词： Domain walls Transport phenomena Graphene Resistivity measurements Tight-binding model

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：