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Introducing an effective coherence function to generate non-uniform ground motion on topographic site using time-domain boundary element method

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Earthquake Engineering and Engineering Vibration 2021年第1期20卷 89-100页

作者： mohsen Isari Reza Tarinejad Faculty of Civil Engineering University of TabrizTabrizEast Azerbaijan ProvinceIran

In this study,a comprehensive parametric analysis was performed on non-uniform excitation of V-shaped topography using the boundary element method in time *** this purpose,wave scattering analysis was carried out on a topography subjected to the SV-wave for different predominant frequencies and shape *** on the numerical results,new coherence and time delay functions are proposed to generate non-uniform ground motion for topographic *** efficiency and accuracy of the proposed functions for real engineering problems are indicated by comparison with observations reported in previous literature.

关键词： site effect time delay boundary element method amplification coherence function

Robust Controller Synthesis and Analysis in Inverter-Dominant Droop-Controlled Islanded Microgrids

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IEEE/CAA Journal of Automatica Sinica 2021年第8期8卷 1401-1415页

作者： S.mohsen Azizi School of Applied Engineering and Technology and the Department of Electrical and Computer EngineeringNew Jersey Institute of TechnologyNJ 07102 USA

This work investigates the problem of controller design for the inverters in an islanded ***-synthesis controllers and local droop controllers are designed to regulate the output voltages of inverters and share power among them,*** designed controllers alleviate the need for additional sensors to measure the states of the system by relying only on output *** is shown that the designed-synthesis controller properly damps resonant oscillations,and its performance is robust to the control-loop time delay and parameter *** stability of a droop-controlled islanded microgrid including multiple distributed generation(DG)units is analyzed by linearizing the nonlinear power flow model around the nominal operating point and applying theorems from linear *** is indicated that the droop controller stabilizes the microgrid system with dominantly inductive tie-line impedances for all values of resistive-inductive loads,while for the case of resistive-capacitive loads the stability is conditioned on an upper bound on the load *** robust performance of the designed-synthesis controller is studied analytically,compared with the similar analysis in an control(benchmark)framework,and verified by simulations for a four DG benchmark ***,the robustness of the droop controllers is analyzed by Monte Carlo simulations in the presence of local voltage fluctuations and phase differences among neighboring DGs.

关键词： Droop control inverter microgrid Monte Carlo simulation robust control μ-synthesis

Hydrodynamic and heat transfer properties of magnetic fluid in porous medium considering nanoparticle shapes and magnetic field-dependent viscosity

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Chinese Journal of Chemical Engineering 2020年第2期28卷 329-339页

作者： mohsen Izadi Masoud Javanahram Seyed mohsen Hashem Zadeh Dengwei Jing Mechanical Engineering Department Lorestan UniversityKhorramabadIran Mechanical Engineering Department Islamic Azad UniversityBushehrIran Department of Mechanical Engineering Shahid Chamran University of AhvazIran School of Energy and Power Engineering State Key Lab of Multiphase Flow in Power EngineeringXi'an Jiaotong UniversityXi'an 710049China

The purpose of this paper is to study the characteristics of the combined convection heat transfer and a micropolar nanofluid flow passing through an impermeable stretching sheet in a porous *** nanofluid flow field is affected by a magnetic field perpendicular to the *** dynamic viscosity of the micropolar nanofluid changes under the influence of the magnetic *** continuity,linear momentum,angular momentum,and energy equations are first simplified using the order of magnitude technique that,along with the applied boundary conditions and the definition of the appropriate parameters,are transferred to the similarity space using the similarity *** the resulting equations are solved using the Runge–Kutta *** distinction of the macroscale and microscale flow fields and temperature fields resulting from different nanoparticle shapes was *** the Hartmann number,the vortex viscosity parameter,the magnetic parameter,the nanoparticle volume fraction,and the permeability parameter of the porous media increased the surface friction on the *** the vortex viscosity parameter,the magnetic parameter,and the volume fraction of the nanoparticles increases the Nusselt number.

关键词： MHD-combined convection Porous media Magnetic micropolar nanofluid

A dynamical approach to the exterior geometry of a perfect fluid as a relativistic star

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Chinese Physics C 2013年第2期37卷 26-38页

作者： mohsen Fathi Department of Physics Islamic Azad University Central Tehran Branch Tehran Iran

In this article, we assume that a cold charged perfect fluid is constructing a spherical relativistic star. Our purpose is the investigation of the dynamical properties of its exterior geometry, through simulating the... 详细信息

关键词： astrophysics relativistic stars geodesics

Development of Voice Control Algorithm for Robotic Wheelchair Using MIN and LSTM Models

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Computers, Materials & Continua 2022年第11期73卷 2441-2456页

作者： mohsen Bakouri Department of Medical Equipment Technology College of Applied Medical ScienceMajmaah UniversityMajmaah City11952Saudi Arabia Department of Physics College of ArtsFezzan UniversityTraghen71340Libya

In this work,we developed and implemented a voice control algorithm to steer smart robotic wheelchairs(SRW)using the neural network *** technique used a network in network(NIN)and long shortterm memory(LSTM)structure integrated with a built-in voice recognition *** Android Smartphone application was designed and configured with the proposed method.A Wi-Fi hotspot was used to connect the software and hardware components of the system in an offline *** operate and guide SRW,the design technique proposed employing five voice commands(yes,no,left,right,no,and stop)via the Raspberry Pi and DC *** native Arabic speakers trained and validated an English speech corpus to determine the method’s overall *** design method of SRW was evaluated in both indoor and outdoor environments in order to determine its time response and *** results showed that the accuracy rate for the system reached 98.2%for the five-voice commends in classifying voices *** interesting finding from the real-time test was that the root-mean-square deviation(RMSD)for indoor/outdoor maneuvering nodes was 2.2∗10–5(for latitude),while that for longitude coordinates was a whopping 2.4∗10–5(for latitude).

关键词： Network in network long short-term memory voice recognition wheelchair

Programmable structured surfaces can change the future of wireless communications

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Light(Science & Applications) 2022年第7期11卷 1341-1342页

作者： Lei Xu mohsen Rahmani Advanced Optics and Photonics Laboratory Department of EngineeringSchool of Science and TechnologyNottingham Trent UniversityNottingham NG118NSUK

An innovative time-varying metasurface has been reported to realise dual-channel data transmissions for light-to-microwave signal *** a novel technique is a remarkable step forward to realise full-spectrum networks for catering for the growing demand for wireless ***,this technique enriches the functionalities of tunable metasurfaces and stimulates new information-oriented applications.

关键词： wireless tunable surfaces

Flow-injection spectrophotometric determination of vanadium with malachite green oxalate by bromate in acidic and micellar medium

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Rare Metals 2011年第3期30卷 216-221页

作者： mohsen Keyvanfarda Narges Abedib Faculty of Science Majlesi BranchIslamic Azad University Group of Chemistry Shahreza BranchIslamic Azad University

A flow injection method is proposed for determining vanadium（V）. The method is based on its catalytic effect on the oxidation of malachite green oxalate by bromate. The reaction was monitored spectrophotometrically by measuring malachite green oxalate absorbance at λmax = 625 nm. The reagents and manifold variables, which have influences on the sensitivity, were investigated and the optimum conditions were established. The optimized conditions made it possible to determine vanadium in the ranges of 10-140 ng/mL with a detection limit of 5.2 ng/mL and a sample rate of 20 ± 5 samples/h.

关键词： vanadium flow injection analysis malachite green oxalate spectrophotometry micellar medium

Reliability analysis of production schedule in multi-element deposits under grade-tonnage uncertainty with multi-destinations for the run of mine material

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International Journal of Mining Science and Technology 2019年第3期29卷 483-489页

作者： mohsen Jamshidi Morteza Osanloo Department of Mining and Metallurgical Engineering Amirkabir University of Technology

Blending contributes to create an opportunity to achieve the target feed material and helps optimize the run of mine(ROM)*** addition,it allows mixing different materials and achieving a wide range of ***,multiple destinations can be considered for *** present study seeks to develop a Mixed Integer Programming(MIP)model for the production scheduling of an iron ore *** on this model,different destinations are considered for mine products with different *** this aim,ten scenarios were considered with a number of different *** results indicated that the maximum NPV in the multiple product scenarios is about 15%more than that of the single product ***,30 realizations were used to evaluate the effect of grade and tonnage *** reliability of the production plan was approximately 61.07%and 62.81%in the first and second period of exploitation,respectively.

关键词： Production Blending Multiple products Reliability Mixed Integer Programming model

OPTICALLY ACTIVE AND FLAME-RETARDANT POLY(AMIDE-IMIDE)S BASED ON PHOSPHINE OXIDE MOIETY AND N,N′-(PYROMELLITOYL)BIS-L-AMINO ACID IN THE MAIN CHAIN:SYNTHESIS AND CHARACTERIZATION

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Chinese Journal of Polymer Science 2010年第4期28卷 517-525页

作者： Khalil Faghihi mohsen Hajibeygi Organic Polymer Chemistry Research Laboratory Department of ChemistryFaculty of ScienceArak UniversityArak 38156Iran

Six new optically active and flame-retardant poly（amide-imide）s PAls 5a-5f containing phosphine oxide moiety as a flame-retardant unit in the main chain were synthesized from direct polycondensation reaction of six chiral N,N＇-（pyromellitoyl）-bis-L-amino acid 3a-3f with bis（3-aminophenyl）phenyl phosphine oxide 4 in a medium consisting of N-methyl-2-pyrrolidone （NMP）, triphenyl phosphite （TPP）, calcium chloride （CaCl2） and pyridine. The polymerization reactions produced a series of optically active poly（amide-imide）s with good yield and good inherent viscosity of 0.34-0.70 dLg^-1. The resulted polymers were fully characterized by means of FTIR and ^1H-NMR spectroscopy, gel permeation chromatography （GPC）, elemental analyses, inherent viscosity and solubility tests. Thermal properties and flameretardant behavior of the PAIs 5a-5f were investigated using thermal gravimetric analysis （TGA and DTG） and limiting oxygen index （LOI）. Data obtained by thermal analysis （TGA and DTG） revealed that these polymers showed good thermal stability. Furthermore, high char yield in TGA and good LOI values indicated that the resulting polymers were capable of exhibiting good flame retardant properties. N,N＇-（pyromellitoyl）-bis-L-amino acids 3a-3f were prepared in quantitative yields by the condensation reaction of pyromellitic dianhydride （1,2,4,5-benzenetetracarboxylicacid-1,2,4,5-dianhydride） 1 with L-alanine 2a, L-valine 2b, L-leucine 2c, L-isoleucine 2d, L-phenyl alanine 2e and L-2-aminobutyric acid 2f in acetic acid solution.

关键词： Optically active Flame-retardant polymers Poly(amide-imide)s Limiting oxygen index