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UKACC International Conference on Control (CONTROL)

作者： Nader Meskin Mohamed A. Mabrok Alexander Lanzon Electrical Engineering Department College of Engineering Qatar University Department of Mathematics Statistics and Physics Mathematics Program College of Arts and Sciences Qatar University Doha Qatar Department of Electrical and Electronic Engineering Control Systems Centre University of Manchester Manchester UK

ISBN: (数字)9798350374261

ISBN: (纸本)9798350374278

Nonlinear negative imaginary systems find application in a range of engineering fields, including the control of flexible structures and air vehicles. Nevertheless, unlike their linear counterparts, the theory for nonlinear negative imaginary systems is not as well-established. In this paper, we propose a generalized k-th order dissipativity framework with respect to a supply rate which is a function of the k-th time-derivative of the system output. It is shown that positive realness and negative imaginaryness can be defined in this general framework in a unified manner. Then, necessary and sufficient conditions for first order dissipativity of nonlinear systems are obtained. These capture and are more general than the negative imaginary property. Moreover, the concept of exponentially negative imaginary systems for both linear and nonlinear systems is developed and the required conditions are obtained.

关键词： Linear systems Sufficient conditions Robust stability Control systems Nonlinear systems Flexible structures

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Reliability of Deployed Organic Photovoltaic Modules

Reliability of Deployed Organic Photovoltaic Modules

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IEEE Conference Photovoltaic Specialists (PVSC)

作者： Hafiz K. M. Sheriff Yongxi Li Sammy Saad Stephen R. Forrest Applied Physics Program University of Michigan Ann Arbor Michigan USA Department of Electrical Engineering University of Michigan Ann Arbor Michigan USA Department of Physics University of Michigan Ann Arbor Michigan USA Department of Materials Science and Engineering University of Michigan Ann Arbor Michigan USA

ISBN: (数字)9781665464260

ISBN: (纸本)9781665475822

The commercial future of organic photovoltaics (OPVs) relies on their efficiency and reliability. Recent progress in the field has ensured the achievement of device efficiency comparable to those of commercial silicon-based photovoltaics (Si-PVs) [1]. In pursuit of reliable devices, recent works have demonstrated the intrinsic stability of both small-molecule, vacuum deposited [2] and non-fullerene acceptor (NFA) – polymer-based devices [3] under controlled laboratory conditions. The final step for outdoor deployment is therefore a demonstration of the reliability of large area OPV modules in the field, subjected to fluctuating environmental conditions such as humidity, temperature, rainfall, snow, and solar intensity. In this work, we develop a customized test facility intended for the study of the reliability of large area OPV modules deployed in outdoor environments. The facility is designed for automated in-situ measurements calibrated to 1 sun solar intensity, AM 1.5 G illumination. Initial data show the modules retain more than 95% of their initial performance for 150 h when exposed to varying solar intensities, temperature fluctuations of -2°C to 10°C, and relative humidity as high as 90%. The only significant extrinsic challenge to device stability observed was the ingress of water into the package. This is mitigated by improved packaging which utilizes polyisobutylene (PIB) encapsulation and a customized insulated glass unit (IGU).

关键词： Temperature measurement Temperature distribution Test facilities Rain Snow Humidity Solar panels Polymers Sun Thermal stability

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Understanding and Tuning Magnetism in van der Waals-type Metal Thiophosphates

arXiv

引用

arXiv 2024年

作者： Basnet, Rabindra Hu, Jin Department of Chemistry & Physics University of Arkansas at Pine Bluff Pine BluffAR71603 United States Department of Physics University of Arkansas FayettevilleAR72701 United States Materials Science and Engineering Program Institute for Nanoscience and Engineering University of Arkansas FayettevilleAR72701 United States

Over the past two decades, significant progress in two-dimensional (2D) materials has invigorated research in condensed matter and material physics in low dimensions. While traditionally studied in three-dimensional systems, magnetism has now been extended to the 2D realm. Recent breakthroughs in 2D magnetism have captured substantial interest from the scientific community, owing to the stable magnetic order achievable in atomically thin layers of the van der Waals (vdW)-type layered magnetic materials. These advances offer an exciting platform for investigating related phenomena in low dimensions and hold promise for spintronic applications. Consequently, vdW magnetic materials with tunable magnetism have attracted significant attention. Specifically, antiferromagnetic metal thiophosphates MPX3 (M = transition metal, P = phosphorus, X = chalcogen) have been investigated extensively. These materials exhibit long-range magnetic orders spanning from bulk to the 2D limit. The magnetism in MPX3 arises from localized moments associated with transition metal ions, making it tunable via substitutions and intercalations. In this review, we focus on such tuning by providing a comprehensive summary of various metal- and chalcogen-substitution and intercalation studies, along with the mechanism of magnetism modulation, and a perspective on the development of this emergent material family. © 2024, CC0.

关键词： Van der Waals forces

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Strongly Confined Atomic Excitation Localization in a Weakly-Driven Atom-Waveguide Interface

arXiv

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arXiv 2024年

作者： Chung, Shao-Hung Chen, Wei Jen, H.H. Institute of Atomic and Molecular Sciences Academia Sinica Taipei10617 Taiwan Department of Physics Center for Quantum Science and Engineering National Taiwan University Taipei10617 Taiwan Molecular Science and Technology Program Taiwan International Graduate Program Academia Sinica Taiwan Physics Division National Center for Theoretical Sciences Taipei10617 Taiwan

An atomic array coupled to a photonic crystal waveguide forms a strongly coupled quantum interface, exhibiting various intriguing collective features of quantum dynamics. Here we consider a homogeneous atomic array and theoretically investigate its steady-state distribution when the incident fields drive the atoms from both sides at asymmetric angles. This effectively creates an interface shared by two zones of atoms under different driving angles. This setup introduces a competition between photon-mediated dipole-dipole interactions and the directionality of coupling, while differences of the travelling phases from the incident angles further influence the overall steady-state behavior. Under this asymmetric driving scheme, the presence of strongly confined localization can be identified, where localization can occur either at the interface or at one of edges. Additionally, we examine the size effect on the atomic localization, deriving an empirical formula to predict parameter regimes that favor interfaced localization. We also consider a defect-driving scheme, where a third zone is created by undriven atoms under symmetric travelling phases. This results in strongly confined single-site excitation localization, which can be explained through analytical solutions under the reciprocal coupling. Finally, we propose several methods for precise control of multiple single-site localizations under the defect-driving scheme. Our results provide insights into driven-dissipative quantum systems with nonreciprocal couplings and pave the way for quantum simulation of exotic many-body states relevant to quantum information applications. Copyright © 2024, The Authors. All rights reserved.

关键词： Photonic crystals

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Automatic 2D Material Detection in Optical Images using Deep Learning Based Computer Vision 4

Automatic 2D Material Detection in Optical Images using Deep...

引用

AI and Optical Data Sciences IV 2023

作者： Ramezani, Fereshteh Parvez, Sheikh Fix, J. Pierce Battaglin, Arthur Whyte, Seamus Borys, Nicholas J. Whitaker, Bradley Electrical and Computer Engineering Department Montana State University Bozeman United States Department of Physics Montana State University Bozeman United States Materials Science Program Montana State University Bozeman United States Optical Technology Center Montana State University Bozeman United States

ISBN: (纸本)9781510659810

Computer vision algorithms can quickly analyze numerous images and identify useful information with high accuracy. Recently, computer vision has been used to identify 2D materials in microscope images. 2D materials have important fundamental properties allowing for their use in many potential applications, including many in quantum information science and engineering. In order to use these materials for research and product development, single-layer 2D crystallites must be prepared through an exfoliation procedure and then identified using reflected light optical microscopy. Performing these searches manually is a time-consuming and tedious task. Deploying deep learning-based computer vision algorithms for 2D material search can automate the flake detection task with minimal need for human intervention. In this work, we have implemented a new deep learning pipeline to classify crystallites of 2D materials based on coarse thickness classifications in reflected-light optical micrographs. We have used DetectorRS as the object detector and trained it on 177 images containing hexagonal boron nitride (hBN) flakes of varying thickness. The trained model achieved a high detection accuracy for the rare category of thin flakes ( © 2023 SPIE.

关键词： Object detection

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Emergent magnetic phases and piezomagnetic effects in MnxNi1−xF2 thin film alloys

引用

Physical Review B 2023年第13期108卷 134437-134437页

作者： Ryan Van Haren Nessa Hald David Lederman Department of Physics University of California Santa Cruz Santa Cruz California 95064 USA Materials Science and Engineering Program School for Engineering of Energy Matter and Transport Arizona State University Tempe Arizona 85287 USA

The effect of random competing single-ion anisotropies in antiferromagnets was studied using epitaxial MnxNi1−xF2 antiferromagnetic thin film alloys grown via molecular beam epitaxy. The crystal structure of this material is tetragonal for all values of x, and the Mn sites have a magnetic easy-axis single-ion anisotropy while the Ni sites have an easy-plane anisotropy perpendicular to the Mn easy axis. Crystallographic and magnetization measurements demonstrated that the thin film alloys were homogeneously mixed and did not phase separate into their constituent parts. Pure MnF2 thin films epitaxially grown on MgF2 exhibited compressive strain along all three crystallographic axes which resulted in piezomagnetic effects. The piezomagnetism disappeared if the film was grown on a (MnNi)F2 graded buffer layer. A mean-field theory fit to the transition temperature as a function of the Mn concentration x, which takes into account piezomagnetic effects, gave a magnetic exchange constant between Mn and Ni ions of JMnNi=0.305±0.003meV. Mean-field theory calculations also predicted the existence of an oblique antiferromagnetic phase in the MnxNi1−xF2 alloy which agreed with the experimental data. A magnetic phase diagram for MnxNi1−xF2 thin film alloys was constructed and showed evidence for the existence of two unique magnetic phases, in addition to the ordinary antiferromagnetic and paramagnetic phases: an oblique antiferromagnetic phase, and an emergent magnetic phase proposed to be either a magnetic glassy phase or a helical phase. The phase diagram is quantitatively different from that of FexNi1−xF2 because of the much larger single-ion anisotropy of Fe2+ compared to Mn2+.

关键词： Epitaxial strain Magnetic anisotropy Magnetic interactions Magnetic phase transitions Magnetism Alloys Antiferromagnets Magnetic thin films Solid solutions Thin films Crystallography Mean field theory Molecular beam epitaxy Susceptibility measurements X-ray diffraction

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Optimizing Fracturing Strategies Via Permeability Effective Ratio for Enhanced Geothermal Systems Based on Heat Production Performance

SSRN

引用

SSRN 2024年

作者： Liu, Gang Ma, Weiwu Xu, Jiangzirui Ahmed, Shams Forruque Yang, Chong School of Energy Science and Engineering Central South University Changsha410083 China Department of Mathematics and Physics North South University Dhaka1229 Bangladesh Science and Math Program

It remains challenging to quantitatively evaluate the direct impact of fractured post-fracturing outcomes on thermal extraction in enhanced geothermal systems (EGS). This study aims to propose a novel fracture evaluation index, "permeability effective ratio", to assess the fracture conductivity for thermal extraction purposes. Using the thermal-hydraulic-mechanics-damage (THMD) model and the extended finite element method (XFEM), it calculates flow rate, production temperature, and heat extraction rate post-hydraulic fracturing. The results show that the permeability effective ratio measures the ratio of fracture permeability used for direct penetration into the well. Optimal heat mining is achieved when injection time is adjusted based on this ratio. Achieving a higher permeability effective ratio in hydraulic fracturing design necessitates keeping low ratio disparity between individual fractures. Alternating fracturing with a 120 s injection time is determined to be the optimal fracturing method. Over the 40 years of heat extraction, the heat extraction process has maintained a production performance of 4.0 kg/s for the average mass flow rate, 159 K for the production temperature drop, and 2.01 MW for the average heat extraction rate. This study could provide a quantitative tool for hydraulic fracturing design and theoretical guidance for geothermal simulation. © 2024, The Authors. All rights reserved.

关键词： Hydraulic fracturing

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Monolayer C5N: A Promising Building Block for the Anode of K-Ion Batteries

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Physical Review Applied 2022年第3期17卷 034055-034055页

作者： Junjie Jin Geetanjali Deokar Pedro M. F. J. Costa Udo Schwingenschlögl Applied Physics Program Physical Science and Engineering Division King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia

Intercalation-type batteries based on the alkali metal K, an earth-abundant element, are attracting increasing attention as alternatives to Li-ion batteries. However, the lack of a high-performance anode limits the success of K-ion batteries. Here, we study the performance of monolayer C5N as a potential building block for the anode. Our theoretical data show that the metallic monolayer can accommodate 2.25 K atoms per formula unit, which corresponds to a specific capacity of 814 mA h g−1, and provides a low diffusion barrier of only 0.11 eV. The volume change of bulk C5N (47%) is found to be smaller than that of graphite (61%; commercial anode material). These predictions will serve the design of future anode materials for K-ion batteries.

关键词： Lithium-alternative batteries 2-dimensional systems Batteries Carbon-based materials Energy materials Nitrides Ab initio molecular dynamics Density functional calculations

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An Online Application of Edge-Cloud Computing for Lithium-Ion Battery with SOC Estimation

An Online Application of Edge-Cloud Computing for Lithium-Io...

引用

IEEE Conference on Vehicle Power and Propulsion (VPPC)

作者： Joelton Deonei Gotz João Pedro dos Reis Mendes José Rodolfo Galvão Emilson Ribeiro Viana Fernanda Cristina Corrêa Milton Borsato Graduate Program in Mechanical Engineering (PPGEM) Federal Technological University of Paraná Curitiba-PR Brazil Graduate Program in Electrical Engineering (PPGEE) Federal Technological University of Paraná Ponta Grossa-PR Brazil Graduate Program in Physics and Astronomy (PPGFA) Federal Technological University of Paraná Curitiba-PR Brazil

The adoption of cloud and edge computing for several application motivates the monitoring and controlling a Lithium-ion batteries (LIB) online and remotely. In these scenarios, this work presents a case of study by the application of a hybrid concept of edge-cloud computing. The edge collects the data from the cells and sent directly to the cloud where several Machine Learning algorithms can be built, trained and tested. Then, the trained models are downloaded to the edge and do inferences in real time. The proposed idea presented still an SOC estimator based on Long Short-Term Memory (LSTM) with average error below 5%.

关键词：

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Affordable ESP32-based monitoring system for microbial fuel cells: real-time analysis and performance evaluation (ESP32-based data logger as a monitoring system for microbial fuel cell)

引用

International Journal of Energy and Water Resources 2024年第2期8卷 199-212页

作者： Indriyani, Y.A. Efendi, R. Rustami, E. Rusmana, I. Anwar, S. Djajakirana, G. Santosa, D.A. Study Program of Soil Sciences Graduate Schools IPB University Bogor Indonesia Department of Mechanical Engineering Faculty of Engineering Universitas Sulawesi Tenggara Kendari Indonesia Department of Physics Faculty of Mathematics and Natural Sciences IPB University Bogor Indonesia Department of Biology Faculty of Mathematics and Natural Sciences IPB University Bogor Indonesia Department of Soil Science and Land Resource Faculty of Agriculture IPB University Bogor Indonesia Biotechnology Center Research and Community Empowerment Institute IPB University Bogor Indonesia

Microbial fuel cells (MFCs) are bioelectrochemical instruments that exploit living microbes as biocatalysts for the conversion of chemical energy stored in the bonds of substrates into electrical energy. Monitoring of current or voltage generation in microbial fuel cells at rigid time intervals is noteworthy. Unfortunately, bioelectrochemical studies are often constrained due to the need for expensive and precise devices for electrochemical measurements. Utilization of low-cost microcontroller as monitoring system can be a considerable solution, compared with data logger that is a high-cost device, or compared with commercial multimeter that have to be used manually in collecting data. In this present work, microbial fuel cells electricity generation was successfully online monitored and the voltage data was also successfully collected using an ESP32 based-data logger. Statistically, there was no significant difference between ESP32 and multimeter in voltage reading, and the average of absolute and relative error values were 0.85 mV and 2.72%, respectively. It suggested that ESP32 could be a possible and low-cost monitoring system for microbial fuel cells bioelectricity generation. Additionally, ADS1115 (an external analogue to digital converter interface to ESP32) has up to four analogue channels, whereas multimeter has just one. In this research, microbial fuel cell powered by isolate KCf1 generated highest voltage value of 789 mV and power density of 541 mW m⁻². © The Author(s), under exclusive licence to Iranian Society of Environmentalists (IRSEN) and Science and Research Branch, Islamic Azad University 2023.

关键词： Biofuel Electricity Electrochemistry Green technology Renewable energy

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