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Neural Regeneration Research 2024年第4期19卷 715-716页

作者： Prakruthi amar Kumar Jennifer N.Dulin Department of Biology Texas A&M UniversityCollege Station Texas A&M Institute for Neuroscience Texas A&M UniversityCollege Station

Neural stem and progenitor cell(NSPC)transpla ntation has emerged as a promising therapeutic strategy for replacing lost neuronal populations and repairing damaged neural circuits following nervous system injury and disease.A great deal of experimental work has investigated the biology of NSPC grafting in preclinical animal models;more recently.

关键词： neural system injured

Assessment of natural frequency of installed offshore wind turbines using nonlinear finite element model considering soil-monopile interaction

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第2期10卷 333-346页

作者： Djillali amar Bouzid Subhamoy Bhattacharya Lalahoum Otsmane Department of Civil Engineering Faculty of Technology University Saad Dahled of Blida Department of Civil and Environmental Engineering Tomas Telford Building University of Surrey Department of Material Engineering Faculty of Sciences and TechnologyUniversity of Médéa

A nonlinear finite element model is developed to examine the lateral behaviors of monopiles, which support offshore wind turbines(OWTs) chosen from five different offshore wind farms in Europe. The simulation is using this model to accurately estimate the natural frequency of these slender structures, as a function of the interaction of the foundations with the subsoil. After a brief introduction to the wind power energy as a reliable alternative in comparison to fossil fuel, the paper focuses on concept of natural frequency as a primary indicator in designing the foundations of OWTs. Then the range of natural frequencies is provided for a safe design purpose. Next, an analytical expression of an OWT natural frequency is presented as a function of soil-monopile interaction through monopile head springs characterized by lateral stiffness KL, rotational stiffness KRand cross-coupling stiffness KLRof which the differences are discussed. The nonlinear pseudo three-dimensional finite element vertical slices model has been used to analyze the lateral behaviors of monopiles supporting the OWTs of different wind farm sites considered. Through the monopiles head movements(displacements and rotations), the values of KL, KRand KLRwere obtained and substituted in the analytical expression of natural frequency for comparison. The comparison results between computed and measured natural frequencies showed an excellent agreement for most cases. This confirms the convenience of the finite element model used for the accurate estimation of the monopile head stiffness.

关键词： Nonlinear finite element analysis Vertical slices model Monopiles under horizontal loading Natural frequency Monopile head stiffness Offshore wind turbines(OWTs)

Removal of Ni(Ⅱ)ions from wastewater by micellar enhanced ultrafiltration using mixed surfactants

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Frontiers of Chemical Science and Engineering 2014年第1期8卷 79-86页

作者： amar D.Vibhandik Kumudini V.Marathe Department of Chemical Engineering Institute of Chemical Technology Mumbai

Ni(Ⅱ) ions were removed from aqueous waste using micellar enhanced ultrafiltration(MEUF) with a mixture of *** surfactant mixture was the nonionic surfactant Tween 80(TW80) mixed with the anionic surfactant sodium dodecyl sulfate(SDS) in different molar ratios ranging from 0.1–*** operational variables of the MEUF process such as pH,applied pressure,surfactant to metal ion ratio and nonionic to ionic surfactant molar ratio(α) were *** of Ni and TW80 was 99% and 98% respectively whereas that for SDS was 65%.The flux and all resistances(fouling resistance,resistance due to concentration polarization)were measured and calculated for entire range of αrespectively.A calculated flux was found to be declined with time,which was mainly attributed to concentration polarization rather than resistance from membrane fouling.

关键词： MEUF Ni (II) ions membrane resistance concentration polarization mixed surfactants

AstroSat Observations of the Be/X-Ray Binary XTE J1946+274 During 2018 and 2021 Outbursts

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Research in Astronomy and Astrophysics 2023年第4期23卷 26-43页

作者： amar Deo Chandra Jayashree Roy P.C.Agrawal Indian Institute of Science Education and Research Kolkata Mohanpur 741246West BengalIndia Inter-University Center for Astronomy and Astrophysics Post Bag 4Pune 411007MaharashtraIndia Department of Astronomy and Astrophysics Tata Institute of Fundamental ResearchHomi Bhabha RoadMumbai 400005MaharashtraIndia

We present the timing and spectral studies of the Be/X-ray binary XTE J1946+274 during its 2018 and 2021 giant outbursts using observations with the SXT and LAXPC instruments on the AstroSat *** the 1998 and 2010 outbursts,where a giant outburst was followed by several low intensity periodic outbursts,the 2018 and 2021 outbursts were single *** X-ray pulsations are detected over a broad energy band covering 0.5–80 keV from the compact *** construct the spin evolution history of the pulsar over two decades and find that the pulsar spins-up during the outbursts but switches to spin-down state in the quiescent periods between the *** resolved pulse profiles generated in several bands in 0.5–80 keV show that the pulse shape varies with the *** energy spectrum of the pulsar is determined for the 2018 and 2021 *** best fit spectral models require presence of cyclotron resonant scattering feature at about 43 keV in the energy spectra of both the *** find indication of possible reversal in the correlation between the cyclotron line energy and luminosity which needs to be ascertained from future *** the best fit spectra the X-ray luminosity of XTE J1946+274 is inferred to be 2.7×10^(37) erg s^(-1) for the 2018 observations and 2.3×10^(37) erg s^(-1) for the 2021 *** discuss possible mechanisms which can drive outbursts in this transient Be X-ray binary.

关键词： accretion-accretion disks-stars neutron-(stars:)pulsars general-X-rays binaries-stars emission-line-Be-X-rays bursts

Modeling and control of a permanent magnet synchronous generator dedicated to standalone wind energy conversion system

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Frontiers in Energy 2016年第2期10卷 155-163页

作者： Louar FATEH Ouari AHMED Omeiri amar Djellad ABDELHAK Bouras LAKHDAR Department of Electrical Engineering University of Badji MokhtarAnnaba 23000 Algeria Department of Electrical Engineering University of 20 Aout 1955Skikda Skikda 21000 Algeria

The interest for the use of renewable energies has increased, because of the increasing concerns of the environmental problems. Among renewable energies, wind energy is now widely used. Wind turbines based on an asynchronous generator with a wound rotor present the inconvenience of requiring a system of tings and brooms and a multiplier, inferring significant costs of maintenance. To limit these inconveniences, certain manufacturers developed wind turbines based on synchronous machines with large number of pairs of poles coupled directly with the turbine, avoiding using the multiplier. If the generator is equipped with permanent magnets, the system of rings and brooms is eliminated. The control of the permanent magnet synchronous generator （PMSG） can be affected with the implementation of various techniques of control. This paper presented a new approach mainly based on the control strategy of power production system based on the PMSG. In fact, a mathematical model that simulates the Matlab chain was established with the introduction of control techniques, such as direct control of the torque （DTC） to control the load side converter （LSC）, the control of the speed of the turbine and the DC-bus voltage ensured by PI regulators. To show the performance of the correctors used, some simulation results of the system were presented and analyzed.

关键词： wind turbine permanent magnet synchronous

Effect of RC wall on the development of plastic rotation in the beams of RC frame structures

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Frontiers of Structural and Civil Engineering 2018年第3期12卷 318-330页

作者： amar KAHIL Aghiles NEKMOUCHE Said BOUKAIS Mohand HAMIZI Naceur Eddine HANNACHI Civil Engineering Department Faculty of Construction Engineering University Mouloud Mammeri Tizi-ouzou 15000 Algeria Civil Engineering Department Faculty of Technology University Abderrahmane Mira - Bejaia 06000 Algeria

The objective of this study is, to interpret the influence of reinforced concrete walls addition in reinforced concrete frame structures considering behavior laws that reflects the actual behavior of such structures, by means of Castem2000computer code （pushover analysis）. A finite element model is proposed in this study, using the TAKEDA modified behavior model with Timoshenko beams elements. This model is validated initially on experimental model. Then the work has focused on the behavior of a RC frame with 3 levels and three bays to better visualize the behavior of plastic hinges. Once the plastic hinge control parameters are identified （plastic rotation, ultimate curvature）, a strengthening by introduction of reinforced concrete walls （RC/wall） at the ends of the reinforced concrete frame （RC/ frame） has been performed. The results show that these RC walls significantly improve the behavior, by a relocation of efforts towards the central part of the beams.

关键词： RC/frame RC/wall moment curvature plastic rotation plastic hinge pushover analysis global models

Effect of stacking sequence on physical, mechanical and tribological properties of glass-carbon hybrid composites

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Friction 2014年第4期2卷 354-364页

作者： Gaurav AGARWAL amar PATNAIK Rajesh kumar SHARMA Jyoti AGARWAL Department of Mechanical Engineering Invertis UniversityBareillyIndia Department of Mechanical Engineering National Institute of Technology(NIT)HamirpurIndia Department of Computer Engineering Rajshree Institute of Management&Technology(RIMT)BareillyIndia

A study was done to determine the effect of best stacking sequence(position and orientation)on the mechanical properties,friction and wear response of hybrid *** main purpose of the study was to determine the best available stacking sequence for which the physical,mechanical and three body abrasive wear rate is *** for mechanical properties(tensile strength,flexural strength,inter laminar shear strength,impact strength and hardness)was done on glass-carbon hybrid *** composites were then subjected to test for three body abrasive wear on a designed experimental *** different factors(sliding velocity,fabric weight percentage,normal load,sliding distance and abrasive particle size)varied in steps to evaluate the friction and three body abrasive wear response of the *** design of experiment using Taguchi’s orthogonal array and analysis of variance(ANOVA)was applied to find out minimum specific wear *** results revealed the significance in arrangement of two different layers of fabric(glass and carbon)and the difference in properties obtained by *** Taguchi experimental analysis it has been observed that three body abrasive wear rate is minimum at 72 cm/s sliding velocity,30 wt.%fabric content,80 N normal load,90 m sliding distance and 125μm abrasive particle *** scanning electron microscope(SEM)studies revealed the dynamics of three‐body abrasive wear and underlying micro‐mechanisms that result in the analysis of three body abrasive wear.

关键词： hybrid composite stacking sequence Taguchi’s method wear mechanism

MEASURES OF WEAK NONCOMPACTNESS AND FIXED POINT THEORY FOR 1-SET WEAKLY CONTRACTIVE OPERATORS ON UNBOUNDED DOMAINS

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Analysis in Theory and Applications 2011年第3期27卷 224-238页

作者： ShaoyuanXu Afif Ben amar Department of Mathematics and Information TechnologyHanshan Normal UniversityChaozhou 521041 Departement de MathematiquesUniversite de Gafsa Cite Universitaire Zarrouk Faculte des Sciences de Gafsa2112 Gafsa Tunisie

The main purpose of this paper is to prove a collection of new fixed point theorems and existence theorems for the nonlinear operator equation F（x） = αx （α≥〉 1） for so-called 1-set weakly contractive operators on unbounded domains in Banach spaces. We also introduce the concept of weakly semi-closed operator at the origin and obtain a series of new fixed point theorems and the existence theorems for the nonlinear operator equation F（x） = αx （α≥1） for such class of operators. As consequences, the main results general- ize and improve the relevant results, which are obtained by O＇Regan and A. Ben amar and M. Mnif in 1998 and 2009 respectively. In addition, we get the famous fixed point theorems of Leray-Schauder, Altman, Petryshyn and Rothe type in the case of weakly sequentially continuous, 1-set weakly contractive （μ-nonexpansive） and weakly semi-closed operators at the origin and their generalizations. The main condition in our results is formulated in terms of axiomatic measures of weak compactness.

关键词： measure of weak noncompactness weakly condensing and weakly nonexpansive weakly sequentially continuous weakly semi-closed at the origin fixedpoint theorem

Theory, simulation and experiment of optical properties of cobalt ferrite(CoFe2O4) nanoparticles

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Journal of Materials Science & Technology 2020年第22期54卷 180-187页

作者： Elham Gharibshahi Brandon D.Young amar S.Bhalla Ruyan Guo Department of Electrical and Computer Engineering University of Texas at San Antonio.One UTSA CircleSan AntonioTX 78249USA

Optical properties of cobalt ferrite(CoFe2O4) nanoparticles are modeled and simulated employing finite element analysis(FEA) and density functional theory(DFT) for different particle sizes. The simulated absorption maxima of electronic excitations is red-shifted from 330 nm to 410 nm using finite element analysis and from 331.27 nm to 409.07 nm using quantum mechanical method, with increasing particle sizes from 40 nm to 50 nm. The measured absorption maxima matched the simulated results reasonably well and red-shifted to longer wavelengths from 315.59 nm to 426.73 nm with the increase in particle sizes from 30 nm to 50 nm. The DFT simulated, FEA simulated and experimentally derived optical band gap energies, Eg, were also acquired and compared. The simulated Egvalues decreased from 3.228 to 2.478 e V and from 3.266 to 2.456 e V, while the experimental Egvalue decreased from 3.473 to 2.697 e V, with increasing the particle sizes. The research demonstrated that the optical absorption of CoFe2O4 nanoparticles can be described with high accuracy using the quantum mechanical interpretation based on DFT. FEA based simulations have shown limitations for smaller(< 40 nm) nanoparticles likely due to the increased surface scattering that prevented a stable solution for simulations beyond the quasistatic limit. The DFT computational tool developed by this study can enable both the low cost computation and highly reliable prediction of optical absorption properties and optical band edges, and thus contribute to understanding and design of CoFe2O4 nanoparticle properties prior to fabrication and functionalization of them, for a wide range of applications especially for sensing and photonic wave modulations.

关键词： Cobalt ferrite(CoFe2O4)nanoparticles Optical properties Band gap energy DFT simulation of nanoparticles COMSOL simulation of nanoparticles

Production optimization under waterflooding with long short-term memory and metaheuristic algorithm

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Petroleum 2023年第1期9卷 53-60页

作者： Cuthbert Shang Wui Ng Ashkan Jahanbani Ghahfarokhi Menad Nait amar Department of Geoscience and Petroleum Norwegian University of Science and TechnologyTrondheimNorway Département Etudes Thermodynamiques Division LaboratoiresSonatrachBoumerdesAlgeria

In petroleum domain,optimizing hydrocarbon production is essential because it does not only ensure the economic prospects of the petroleum companies,but also fulfills the increasing global demand of ***,applying numerical reservoir simulation(NRS)to optimize production can induce high computational *** models are suggested to alleviate this challenge because they are computationally less demanding and able to yield reasonably accurate *** this paper,we demonstrated how a machine learning technique,namely long short-term memory(LSTM),was applied to develop proxies of a 3D reservoir *** techniques were employed to create numerous simulation cases which served as the training database to establish the *** blind validating the trained proxies,we coupled these proxies with particle swarm optimization to conduct production *** training and blind validation results illustrated that the proxies had been excellently developed with coefficient of determination,R2 of *** also compared the optimization results produced by NRS and the *** comparison recorded a good level of accuracy that was within 3%*** proxies were also computationally 3 times faster than ***,the proxies have served their practical purposes in this study.

关键词： Production optimization Numerical reservoir simulation Machine learning Long short-term memory(LSTM) Dynamic proxies Particle swarm optimization(PSO)