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Plasma Science and Technology 2013年第6期15卷 586-592页

作者： vahid abbasi Ahmad GHOLAMI Kaveh NIAYESH Electrical Engineering Department Iran University of Science and TechnologyNarmakTehranIran School of Electical and Computer Engineering College of EngineeringUniversity of TehranIR-14395 TehranIran

In a gas circuit breaker,metal vapor resulting from electrode erosion is injected into the arc *** arc then burns in a mixture of SF;and electrode vapor,which has properties significantly different from those of pure SF;.Thermodynamic properties and transport coefficients of thermal plasmas formed in SF;-copper vapor mixtures change as a function of temperature and *** property that is mostly affected by the presence of copper is electrical conductivity,which is important in magnetohydrodynamic（MHD） *** this study,the transport coefficients of SF;in the presence of 10 percent copper are considered as the basis of MHD *** are made between the results during arc formation for pure SF;and SF;-Cu mixture in a medium voltage（MV） circuit *** to the transport coefficients influenced by the SF;-Cu mixture,the distribution of the electric potential, temperature,electromagnetic force density and current density of the arc column are presented and ***,the arc stability and pinch effect near current zero with 3-D simulation are investigated,which is advantageous to improving the efficiency of arc plasma simulation.

关键词： magnetohydrodynamic(MHD) electromagnetic force SF6-Cu mixture transport coefficients pure SF6

Three-Dimensional Simulation of Plasma Deformation During Contact Opening in a Circuit Breaker,Including the Analysis of Kink Instability and Sausage Instability

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Plasma Science and Technology 2012年第11期14卷 996-1001页

作者： vahid abbasi Ahmad GHOLAMI Kaveh NIAYESH High Voltage and Magnetic Material Research Center Electrical Engineering DepartmentIran University of Science and Technology School of Electrical and Computer Engineering University of Tehran

A three-dimensional （3-D） transient model has been developed to investigate plasma deformation driven by a magnetic field and its influence on arc stability in a circuit breaker. The 3-D distribution of electric current density is obtained from a current continuity equation along with the generalized Ohm＇s law; while the magnetic field induced by the current flowing through the arc column is calculated by the magnetic vector potential equation. When gas interacts with an arc column, fundamental factors, such as Ampere＇s law, Ohm＇s law, the turbulence model, transport equations of mass, momentum and energy of plasma flow, have to be coupled for aria- lyzing the phenomenon. The coupled interactions between arc and plasma flow are described in the fl＇amework of time-dependent magnetohydrodynamic （MHD） equations in conjunction with a K-~ turbulence model. Simulations have been focused on sausage and kink instabilities in plasma （these phenomena are related tO pinch effects and electromagnetic fields）. The 3-D sjm- ulation reveals the relation between plasma deformation and instability phenomena, which affect arc stability during circuit breaker operation. Plasma deformation is the consequence of coupled interactions between the electromagnetic force and plasma flow described in simulations.

关键词： magnetohydrodynamic (MHD) plasma deformation electromagnetic force kink instability sausage instability

A Method for Improving Power Distribution Characteristics of Space Time Block Codes

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China Communications 2020年第6期17卷 223-234页

作者： vahid abbasi Mahrokh GShayesteh Department of Electrical Engineering Urmia UniversityUrmia 57561-15311Iran Wireless Research Lab. Elec.Eng.Dep.ACRISharif University of TechnologyTehran 11365-9363Iran

Improving power distribution characteristics of space time block codes(STBCs),namely peak to average power ratio(PAPR),average to minimum power ratio(Ave/min),and probability of transmitting"zero"by antenna,makes easier their practical *** this end,this study proposes to multiply full diversity STB C with a non-singular matrix in multiple input multiple output(MIMO)or multiple input single output(MISO)systems with linear or maximum likelihood(ML)*** is proved that the obtained code achieves full diversity and the order of detection complexity does not *** proposed method is applied to different types of *** bit error rate(BER)and power distribution characteristics of the new codes demonstrate the superiority of the introduced ***,lower and upper bounds on the BER of the obtained STBCs are derived for all *** proposed method provides trade-off among PAPR,spectral efficiency,energy efficiency,and BER.

关键词： full diversity linear receiver maximum likelihood peak to average power ratio power distribution space time block codes

Global systematic review and meta-analysis of knowledge, attitudes, and practices towards dengue fever among the general population

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Asian Pacific Journal of Tropical Medicine 2024年第5期17卷 191-207,I0001-I0003页

作者： Abdolreza Sotoodeh Jahromi Mohammad Jokar Arman Abdous Nader Sharifi Tahere abbasi vahid Rahmanian Zoonoses Research Center Jahrom University of Medical SciencesJahromIran Faculty of Veterinary Medicine Karaj BranchIslamic Azad UniversityKarajIran Department of Public Health Khomein University of Medical SciencesKhomeinIran Research Center for Social Determinants of Health Jahrom University of Medical SciencesJahromIran Department of Public Health Torbat Jam Faculty of Medical SciencesTorbat JamIran

Objective:To determine the global level of knowledge,attitudes,and practices towards dengue fever among the general ***:To complete this systematic review and meta-analysis,a thorough search for pertinent English-language literature was undertaken during the study's extension until October *** search used Google Scholar,Scopus,PubMed/MEDLINE,Science Direct,Web of Science,EMBASE,Springer,and ProQuest.A quality assessment checklist developed using a modified Newcastle-Ottawa Scale for the cross-sectional study was used to evaluate the risk of bias in the included *** variance and Cochran Q statistics were employed in the STATA software version 14 to assess study *** there was heterogeneity,the Dersimonian and Liard random-effects models were ***:59 Studies totaling 87353 participants were included in this *** investigations included 86278 participants in 55 studies on knowledge,20196 in 33 studies on attitudes,and 74881 in 29 studies on *** pooled estimates for sufficient knowledge,positive attitudes,and dengue fever preventive behaviors among the general population were determined as 40.1%(95%CI 33.8%-46.5%),46.8%(95%CI 35.8%-58.9%),and 38.3%(95%CI 28.4%-48.2%),*** exhibits the highest knowledge level at 63.5%,and Africa shows the lowest at 20.3%.Positive attitudes are most prevalent in the Eastern Mediterranean(54.1%)and Southeast Asia(53.6%),contrasting sharply with the Americas,where attitudes are notably lower at 9.05%.Regarding preventive behaviors,the Americas demonstrate a prevalence of 12.1%,Southeast Asia at 28.1%,Western Pacific at 49.6%,Eastern Mediterranean at 44.8%,and Africa at 47.4%.Conclusions:Regional disparities about the knowledge,attitude and preventive bahaviors are evident with Europe exhibiting the highest knowledge level while Africa has the *** findings emphasize the importance of targeted public health interventions tailored to regional

关键词： Break-bone fever Knowledge Attitudes Practices

A multi-functional dynamic state estimator for error validation:measurement and parameter errors and sudden load changes

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Frontiers of Information Technology & Electronic Engineering 2016年第11期17卷 1218-1227页

作者： Mehdi AHMADI JIRDEHI Reza HEMMATI vahid abbasi Hedayat SABOORI Department of Electrical Engineering Kermanshah University of Technology

We propose a new and efficient algorithm to detect, identify, and correct measurement errors and branch parameter errors of power systems. A dynamic state estimation algorithm is used based on the Kalman filter theory. The proposed algorithm also successfully detects and identifies sudden load changes in power systems. The method uses three normalized vectors to process errors at each sampling time: normalized measurement residual, normalized Lagrange multiplier, and normalized innovation vector. An IEEE 14-bus test system was used to verify and demonstrate the effectiveness of the proposed method. Numerical results are presented and discussed to show the accuracy of the method.

关键词： Dynamic state estimation Kalman filter Measurement errors Branch parameter errors Sudden load changes

Sustainable ammonia synthesis:An in-depth review of non-thermal plasma technologies

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Journal of Energy Chemistry 2024年第9期96卷 1-38页

作者： vahid Shahed Gharahshiran Ying Zheng Department of Chemical and Biochemical Engineering Thompson Engineering BuildingWestern UniversityLondonON N6A 5B9Canada

Ammonia serves both as a widely used fertilizer and environmentally friendly energy source due to its high energy density,rich hydrogen content,and emissions-free ***,it offers convenient transportation and storage as a hydrogen *** dominant method used for large-scale ammonia production is the Haber-Bosch process,which requires high temperatures and pressures and is ***,non-thermal plasma offers an eco-friendly alternative for ammonia synthesis,gaining significant *** enables ammonia production at lower temperatures and pressures using plasma *** review provides insights into the catalyst and reactor developments,which are pivotal for promoting ammonia efficiency and addressing existing *** first,the reaction kinetics and mechanisms are introduced to gain a comprehensive understanding of the reaction pathways involved in plasma-assisted ammonia ***,the enhancement of ammonia synthesis efficiency is discussed by developing and optimizing plasma reactors and effective *** effect of other feeding sources,such as water and methane,instead of hydrogen is also ***,the challenges and possible solutions are outlined to facilitate energy-saving and enhance ammonia efficiency in the future.

关键词： Nitrogen fixation Ammonia synthesis NH_(3) Non-thermal plasma Ni Ru catalyst

Nonlinear dynamic modeling of planar moving Timoshenko beam considering non-rigid non-elastic axial effects

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Applied Mathematics and Mechanics(English Edition) 2024年第3期45卷 479-496页

作者： M.abbasi GAVARI M.R.HOMAEINEZHAD Faculty of Mechanical Engineering K.N.Toosi University of TechnologyTehran 19991-43344Iran

Due to the importance of vibration effects on the functional accuracy of mechanical systems,this research aims to develop a precise model of a nonlinearly vibrating single-link mobile flexible *** manipulator consists of an elastic arm,a rotary motor,and a rigid carrier,and undergoes general in-plane rigid body motion along with elastic transverse *** accurately model the elastic behavior,Timoshenko’s beam theory is used to describe the flexible arm,which accounts for rotary inertia and shear deformation *** applying Newton’s second law,the nonlinear governing equations of motion for the manipulator are derived as a coupled system of ordinary differential equations(ODEs)and partial differential equations(PDEs).Then,the assumed mode method(AMM)is used to solve this nonlinear system of governing equations with appropriate shape *** assumed modes can be obtained after solving the characteristic equation of a Timoshenko beam with clamped boundary conditions at one end and an attached mass/inertia at the *** addition,the effect of the transverse vibration of the inextensible arm on its axial behavior is *** the axial rigidity,the effect makes the rigid body dynamics invalid for the axial behavior of the ***,numerical simulations are conducted to evaluate the performance of the developed model,and the results are compared with those obtained by the finite element *** comparison confirms the validity of the proposed dynamic model for the *** to the mentioned features,this model can be reliable for investigating the system’s vibrational behavior and implementing vibration control algorithms.

关键词： planar moving Timoshenko beam non-rigid non-elastic axial effect as-sumed mode method(AMM) nonlinear motion analysis

Bridging digital and electromagnetic realms for enhanced wireless communication: current space

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National Science Review 2024年第4期11卷 9-10页

作者： Qammer H.abbasi James Watt School of Engineering University of Glasgow

Digital, coding, and programmable metasurfaces have attracted widespread attention in wireless communication fields owing to their distinguished capability in manipulating electromagnetic (EM)waves [1]. Metasurfaces consist of planar subwavelength meta-atoms and are a twodimensional form of metamaterials [2].These engineered surfaces can flexibly control the properties of EM waves, such as magnitude, phase, and polarization. In particular, coding metasurfaces provide a bridge between the digital world and the physical world. Accordingly, modeling and analyzing the coding metasurfaces from the perspective of information theory has become one of the most important research focuses of the scientific community [3,4].

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Movement Trend Alterations in the Periaqueductal Gray(PAG)-Employed Ratbot Navigation Are Correlated with Stimulation Parameters

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Journal of Bionic Engineering 2024年第2期21卷 866-876页

作者： Sina Khajei Abed Khorasani Mohammad Reza Afarinesh vahid Sheibani Neuroscience Research Center Institute of NeuropharmacologyKerman University of Medical SciencesKerman***Iran Cognitive Neuroscience Research Center Institute of NeuropharmacologyKerman University of Medical SciencesKerman***Iran

In previous studies,Periaqueductal Gray(PAG)stimulation was used to stop ratbots from *** to the homology between the PAG and the intercollicular nucleus,which has been used for forward movement in birds,we investigated the possibility of PAG application to induce forward locomotion for the first *** a corridor maze,the traveled distances via PAG electrical stimulation were examined in nine Wistar male rats during three sessions.A custom-designed stimulator was developed to apply the *** results showed reductions in responses to stimulation over ***,the traveled distances had negative slopes during the consecutive trials(in 8 out of the 9 rats),and the slope mean was significantly different from *** was a strong correlation between the stimulation parameters(electric Charge per Phase(CPP)and the Number of Pulses(NP))and the observed *** negative Movement Slopes(MS)were highly correlated with the CPP and the NP,as the Pearson's linear correlation coefficients were−0.87 and−0.79,*** MS-CPP coefficients of determination(R-squared)were also between 0.76 and *** addition,the MS-NP coefficients of determination were between 0.63 and ***,it is concluded that the electrical stimulation parameters influence the behavioral outcomes ***,the PAG area may be considered a suitable candidate for forward locomotion control in the future if the area is harnessed effectively to prevent undesirable chaotic behaviors.

关键词： Periaqueductal Gray(PAG) Navigation Ratbot Animal-robot Forward locomotion Movement slope

The Anxiolytic and Antidepressant Effect of Stachys Lavandulifolia in the Experimental Pentylenetetrazole-Induced Rat Model of Acute Seizure

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World Journal of Traditional Chinese Medicine 2024年第1期10卷 114-120页

作者： vahid Azizi Farzin Allahyari Abdolkarim Hosseini Department of Animal Sciences Faculty of Life Sciences and BiotechnologyShahid Beheshti UniversityTehranIran

Objective:In traditional medicine,Stachys lavandulifolia or mountain tea has been used in the treatment of arthritis and rheumatoid arthritis.A leaf extract from this plant is also thought to be effective in treating epilepsy as well as other neurological *** assess the effect of *** extract(SLE),rats were exposed to a stress and anxiety model caused by *** and Methods:A challenge dose of pentylenetetrazole(PTZ)(60 mg/kg)was used to induce seizures in male Wistar rats(200-250 g).Animal treated with an intraperitoneal injection of either SLE(50 mg/kg)or sodium valproate(100 mg/kg)alone or in combination 30 min before PTZ *** effect of stress and anxiety was assessed using an open field test(OFT),forced swim test(FST),and elevated plus maze(EPM).At the end of the experiment,anesthesia was used to euthanize rats,and their blood serum was collected for measurements of glutathione(GSH),malondialdehyde(MDA),and GSH peroxidase(GPx).Results:In contrast to the control group,those treated with PTZ exhibited depressive *** 50 mg/kg,SLE provided protection against seizures induced by *** also reduced seizure-induced stress and anxiety,significantly improving FST,EPM,and OFT compared with the PTZ-treated *** decreasing MDA levels and restoring the antioxidant enzymes GSH and GPx,SLE treatment protects against seizure-induced anxiety and ***:SLE inhibits oxidative stress damage and seizure-induced stress by inhibiting seizures'inhibitory effects.

关键词： Anxiety behavior depression oxidative stress traditional medicine