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An Adaptive Data-driven Method Based on Fuzzy Logic for Determining Power System Voltage Status

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 707-718页

作者： Sirwan Shazdeh hêmin Golpîra hassan Bevrani the SMGRC University of KurdistanSanandajIran Power Systems Modeling&Simulation Lab Department of Electrical EngineeringUniversity of KurdistanKurdistanSanandaj 66177-15175Iran

this paper proposes an adaptive method based on fuzzy logic that utilizes data from phasor measurement units(PMUs) to assess and classify generating-side voltage trajectories. the voltage variable and its associated derivatives are used as the input variables of a fuzzy-logic block. In addition, the voltage trajectory is compared with the pre-selected pilot-bus voltage to make a reliable decision about the voltage operational state. Different types of short-term voltage dynamics are considered in the proposed method. the fuzzy membership functions are determined using a systematic method that considers the current situation of the voltage trajectory. Finally, the voltage status is categorized into four classes to determine appropriate remedial actions. the proposed method is validated on a IEEE 73-bus power system in a MAtLAB environment.

关键词： Fuzzy logic fault-induced delayed voltage recovery phasor measurement unit(PMU) short-term voltage stability situational awareness voltage classification

Solvation Effects on the Dielectric Constant of 1 M LiPF6 in Ethylene Carbonate:Ethyl Methyl Carbonate 3:7

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Energy & Environmental Materials 2024年第1期7卷 253-256页

作者： julian Self Nathan t.hahn Kristin A.Persson Department of Chemical Engineering Polytechnique MontrealMontrealQC H3T 1J4Canada Department of Materials Science and Engineering University of CaliforniaBerkeleyCA 94720USA Energy technologies Area Lawrence Berkeley National LaboratoryBerkeleyCA 94720USA Material Physical and Chemical Sciences CenterSandia National LaboratoriesAlbuquerqueNM 87185USA

We report the dielectric constant of 1 M LiPF_(6)in EC:EMC 3∶7 w/w(ethylene carbonate/ethyl methyl carbonate)in addition to neat EC:EMC 3∶7 w/*** three Debye relaxations,the static permittivity value,or dielectric constant,is extrapolated to 18.5,which is compared to 18.7 for the neat solvent *** EC solvent is found to strongly coordinate with the Li^(+)cations of the salt,which results in a loss of dielectric contribution to the ***,the small amplitude and large uncertainty in relaxation frequency for EMC cloud definitive identification of the Li^(+)solvation ***,the loss of the free EC permittivity contribution due to Li^(+)solvation is almost completely balanced by the positive contribution of the associated LiPF_(6)salt,demonstrating that a significant quantity of dipolar ion pairs exists in 1 M LiPF_(6)in EC:EMC 3∶7.

关键词： batteries dielectric relaxation spectroscopy electrolytes

Storylines of family medicine Ⅰ:framing family medicine–history,values and perspectives

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Family Medicine and Community health 2024年第S3期12卷 2-11页

作者： William B Ventres Leslie A Stone Kathleen t Rowland Richard h Streiffer Michael D Macechko julia A Roulier Jeffrey M Borkan Larry A Green Family and Preventive Medicine University of Arkansas for Medical Sciences College of MedicineLittle RockArkansasUSA Family and Preventive Medicine Rush Medical College of Rush UniversityChicagoIllinoisUSA College of Community health Sciences University of AlabamaTuscaloosaAlabamaUSA UAMS Northwest Regional Campus Family Medicine Residency Program FayettevilleArkansasUSA UAMS North Central Regional Campus Family Medicine Residency Program BatesvilleArkansasUSA Family Medicine Brown University Warren Alpert Medical SchoolProvidenceRhode IslandUSA University of Colorado School of Medicine AuroraColoradoUSA

Storylines of Family Medicine is a 12-part series of thematically linked mini-essays with accompanying illustrations that explore the many dimensions of family medicine,as interpreted by individual family physicians and medical educators in the USA and elsewhere around the ***‘Ⅰ:framing family medicine—history,values,and perspectives’,the authors address the following themes:‘Notes on Storylines of Family Medicine’,‘Family medicine—the generalist specialty’,‘Family medicine’s achievements—a glass half full assessment’,‘Family medicine’s next 50 years—toward filling our glasses’,‘Four enduring truths of family medicine’,‘Names matter’,‘Family medicine at its core’and‘the ecology of medical care.’May readers find much food for thought in these essays.

关键词： glasses illustration Notes

Optimizing Average Electric Power During the Charging of Lithium-Ion Batteries through the taguchi Method

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transactions of tianjin University 2024年第2期30卷 152-166页

作者： Mohd h.S.Alrashdan Department of Electrical Engineering Al-Hussein Bin Talal UniversityMaan 71110Jordan

In recent times, lithium-ion batteries have been widely used owing to their high energy density, extended cycle lifespan, and minimal self-discharge rate. the design of high-speed rechargeable lithium-ion batteries faces a significant challenge owing to the need to increase average electric power during charging. this challenge results from the direct influence of the power level on the rate of chemical reactions occurring in the battery electrodes. In this study, the taguchi optimization method was used to enhance the average electric power during the charging process of lithium-ion batteries. the taguchi technique is a statistical strategy that facilitates the systematic and efficient evaluation of numerous experimental variables. the proposed method involved varying seven input factors, including positive electrode thickness, positive electrode material, positive electrode active material volume fraction, negative electrode active material volume fraction, separator thickness, positive current collector thickness, and negative current collector thickness. three levels were assigned to each control factor to identify the optimal conditions and maximize the average electric power during charging. Moreover, a variance assessment analysis was conducted to validate the results obtained from the taguchi analysis. the results revealed that the taguchi method was an eff ective approach for optimizing the average electric power during the charging of lithium-ion batteries. this indicates that the positive electrode material, followed by the separator thickness and the negative electrode active material volume fraction, was key factors significantly infl uencing the average electric power during the charging of lithium-ion batteries response. the identification of optimal conditions resulted in the improved performance of lithium-ion batteries, extending their potential in various applications. Particularly, lithium-ion batteries with average electric power of 16 W and 17

关键词： Lithium-ion batteries Average electric power during charging taguchi method COMSOL Multiphysics software C rate L27 orthogonal array

Microstructure evolution and shape memory behaviors of Ni_(47)ti_(44)Nb_(9)alloy subjected to multistep thermomechanical loading with different prestrain levels

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Journal of Materials Science & technology 2024年第4期171卷 80-93页

作者： Y.h.Zhang h.Li Z.W.Yang X.Liu Q.F.Gu State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Shaanxi Key Laboratory of high-Performance Precision Forming technology and Equipment Northwestern Polytechnical UniversityXi’an 710072China

Ni_(47)ti_(44)Nb_(9)shape memory alloy(SMA)is a promising material in the aerospace field due to its wide transformation *** application of shape memory effect depends on multistep thermomechan-ical loading,viz.,low-temperature deformation and subsequent heating to ***-temperature deformation prestrain plays a pivotal role in shape memory properties tailoring of SMA ***,microstructure evolution and deformation mechanisms of Ni_(47)ti_(44)Nb_(9)SMA subjected to vari-ous prestrain levels are still *** this end,microstructure evolution and shape memory behaviors of Ni_(47)ti_(44)Nb_(9)alloy subjected to multistep thermomechanical loading with prestrain levels of 8%-16%at-28℃(M_(s)+30℃)were *** results demonstrate that the stress-strain curve of the specimen exhibits four distinct stages at a maximal prestrain of 16%.Whereas stageⅡand stageⅢend at prestrains of∼8%and∼12%,*** stageⅡ,the stress-induced martensitic transformation is accompanied by the dislocation slip of the Niti matrix andβ-Nb *** stageⅢ,in addition to the higher density of dislocations and further growth of stress-induced martensite variants(SIMVs),(001)compound twins are introduced as a result of the(001)deformation twinning in stress-induced ***{20-1}martensite twins are gradually introduced in stageⅣ.Correspondingly,after subsequent unloading and heating,a higher density oftaustenite twins form in the specimen with a larger prestrain of 16%.With increasing prestrain from 8%to 16%,the recoverable strainε_(re)^(t)upon heating increases first and then ***ε_(re)^(t)obtains a maximum of 7.03%at 10%prestrain and de-creases to 6.17%at 16%*** increase ofε_(re)^(t)can be attributed to the formation of new SIMVs,the further growth of existing SIMVs,and the recoverable(001)compound *** the decrease ofε_(re)^(t)is mainly associated with the irrecoverable strain by{20−1}martensite *** effe

关键词： Ni_(47)ti_(44)Nb_(9)shape memory alloy Wide transformation hysteresis thermomechanical loading Microstructure evolution Shape memory behaviors Stress-induced martensitic transformation Deformation twinning

Effects of layer interactions on instantaneous stability of finite Stokes flows

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 69-84页

作者： Chen ZhAO Zhenli ChEN C.t.MUtASA Dong LI School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China

the stability analysis of a finite Stokes layer is of practical importance in flow control. In the present work, the instantaneous stability of a finite Stokes layer with layer interactions is studied via a linear stability analysis of the frozen phases of the base flow. the oscillations of two plates can have different velocity amplitudes, initial phases, and frequencies. the effects of the Stokes-layer interactions on the stability when two plates oscillate synchronously are analyzed. the growth rates of two most unstable modes when δ t equal, and δ = δ*/h*, where δ*and h*are the Stokes-layer thickness and the half height of the channel, respectively. however, their vorticities are different. the vorticity of the most unstable mode is symmetric, while the other is asymmetric. the Stokes-layer interactions have a destabilizing effect on the most unstable mode when δ have a stabilizing effect when δ > 0.68. however, the interactions always have a stabilizing effect on the other unstable mode. It is explained that one of the two unstable modes has much higher dissipation than the other one when the Stokes-layer interactions are strong. We also find that the stability of the Stokes layer is closely related to the inflectional points of the base-flow velocity profile. the effects of inconsistent velocity-amplitude, initial phase, and frequency of the oscillations on the stability are analyzed. the energy of the most unstable eigenvector is mainly distributed near the plate of higher velocity amplitude or higher oscillation frequency. the effects of the initial phase difference are complicated because the base-flow velocity is extremely sensitive to the initial phase.

关键词： finite Stokes layer instantaneous stability Stokes-layer interaction asynchronous oscillation

A Comprehensive Review on Charging topologies and Power Electronic Converter Solutions for Electric Vehicles

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 675-694页

作者： Abdelfatah Ali hossam h.h.Mousa Mostafa F.Shaaban Maher A.Azzouz Ahmed S.A.Awad the Department of Electrical Engineering American University of Sharjah26666 SharjahUnited Arab Emirates the Department of Electrical Engineering South Valley University83523 QenaEgypt the Department of Electrical and Computer Engineering University of WindsorWindsorON N9B 3P4 Canada Electrical Engineering Department Qatar UniversityDoha 2713Qatar Department of Electrical and Computer Engineering Sultan Qaboos UniversityMuscat123Oman

Electric vehicles(EVs)are becoming more popular worldwide due to environmental concerns,fuel security,and price *** performance of EVs relies on the energy stored in their batteries,which can be charged using either AC(slow)or DC(fast)***,EVs can also be used as mobile power storage devices using vehicle-to-grid(V2G)*** electronic converters(PECs)have a constructive role in EV applications,both in charging EVs and in ***,this paper comprehensively investigates the state of the art of EV charging topologies and PEC solutions for EV *** examines PECs from the point of view of their classifications,configurations,control approaches,and future research prospects and their impacts on power *** can be classified into various topologies:DC-DC converters,AC-DC converters,DC-AC converters,and AC-AC *** address the limitations of traditional DC-DC converters such as switching losses,size,and high-electromagnetic interference(EMI),resonant converters and multiport converters are being used in high-voltage EV ***,power-train converters have been modified for high-efficiency and reliability in EV *** paper offers an overview of charging topologies,PECs,challenges with solutions,and future trends in the field of the EV charging station applications.

关键词： Charging station charging topology electric vehicle power electronic converter vehicle-to-grid

Assessment of water quality suitability for agriculture in a potentially leachate-contaminated region

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Journal of Groundwater Science and Engineering 2024年第3期12卷 281-292页

作者： Aida h Baghanam Vahid Nourani Zohre Khodaverdi Amirreza t Vakili Department of water resources engineering Faculy of civil engineeringUniversity of TabrizIran

Dump sites pose a significant threat to groundwater resources due to the possibility of leachate leakage into the *** study investigated the impact of leachate on groundwater quality in the southwest region of Zanjan City,Iran,where groundwater is utilized for drinking,agricultural,and industrial *** analyzed 18 parameters of dump site leachate,including physicochemical,heavy metals,and bacterial properties,alongside 13 groundwater *** was conducted twice,in November 2020 and June 2021,within a five-kilometer radius of the Zanjan dump *** utilized the Leachate Pollution Index(LPI)to evaluate potential groundwater contamination by leachate leakage from nearby ***,due to the predominant agricultural activities in the study area,various indices were employed to assess groundwater quality for agricultural purposes,such as Sodium Adsorption Ratio(SAR),Soluble Sodium Index(SSI),Kelly Ratio(KR),and Permeability Index(PI).Our analysis revealed no observed contamination related to leachate in the study area according to the LPI ***,with the persistent pollution threat,implementing sanitary measures at the dump site is crucial to prevent potential impacts on groundwater ***,the assessment of groundwater quality adequacy for irrigation yielded satisfactory results for SAR,KR,and PI ***,during both the dry(November 2020)and wet seasons(June 2021),the SSP index indicated that 80%of the samples were not classified as excellent,suggesting groundwater may not be suitable for ***,our qualitative study highlights the significant impact of the dry season on groundwater quality in the study area,attributed to elevated concentration levels of the investigated parameters within groundwater sources during the dry season.

关键词： Leachate pollution index(LPI) Sodium adsorption ratio(SAR) Soluble sodium index(SSI) Water quality in agriculture

Decorating crystalline YFe_(2-x)Al_(x) on the Mg_(60)La_(10)Ni_(20)Cu_(10) amorphous alloy as “hydrogen pump” to realize fast de/hydrogenation

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Journal of Materials Science & technology 2024年第6期173卷 72-79页

作者： L.J.huang h.Wang L.Z.Ouyang M.Zhu h.J.Lin School of Materials Science and Engineering Key Laboratory of Advanced Energy Storage Materials of Guangdong ProvinceSouth China University of TechnologyGuangzhou 510641China Institute of Advanced Wear&Corrosion Resistance and Functional Materials Jinan UniversityGuangzhou 510632China

Mg-based amorphous alloys are one of the potential hydrogen storage materials but suffer from sluggish dehydrogenation/hydrogenation(de/hydrogenation)*** this work,as a new strategy,a hydrogen pump is built on the surface of amorphous alloys to solve this *** milling crystalline YFe_(2-x)Al_(x) hydrogen storage alloy with Mg_(60)La_(10)Ni_(20)Cu_(10) amorphous alloy,fine crystalline particles were seeded on amorphous alloy powder to form a“strawberry”*** to the tEM observation,a metallurgical bonding boundary formed between the Mg-based amorphous matrix and the Y-Fe-Al crystalline *** microstructure and de/hydrogenation kinetics investigation,the“hydrogen pump”effect of the seeded crystalline alloy was confirmed,which makes it much easier for the hydrogen to dissociate on and diffuse through the surface of the Mg-based amorphous *** such effect,the h absorption rate of Mg_(60)La_(10)Ni_(20)Cu_(10) amorphous alloy became almost eight times faster and it absorbs ~2.8 wt.% in 1 h at 130℃ under 4.5 MPa-h_(2).Further,fast hydrogenation can even achieve at 70℃ and the low-temperature dehydrogenation kinetics of the amorphous hydride can be also greatly *** present work proves that surface modification is of great importance for obtaining Mg-based amorphous alloy with ideal hydrogen storage performance.

关键词： hydrogen storage Mg-based amorphous alloy hydrogen pump Composite structure