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Earthquake Engineering and Engineering Vibration 2022年第2期21卷 377-393页

作者： afshin naserpour Mojtaba Fathi Department of Civil Engineering Engineering FacultyRazi UniversityKermanshah ***Iran

A multiple rocking wall-frame(MRWF)system,in which the wall panels are directly connected to the adjacent beams and foundation is presented *** the MRWF system,the unbonded post-tensioned(PT)tendons are used to promote the self-centering ability,and O-shaped steel dampers are applied to enhance the energy dissipation capacity and reparability of the ***,analytical equations are proposed to determine the behavior of the O-shaped ***,the MRWF system is numerically evaluated for five different models consisting of rocking walls with varying numbers and arrangements while keeping the total effective width of wall panels *** numerical results show that with an increase in the number of wall panels and a decrease in the wall width,the hysteretic behavior of the MRWF system tends to the ideal flag-shaped pattern,resulting in little damage to the beams,insignificant strain in the wall toe,negligible residual drifts and damage index of less than 0.2 under severe *** contrast,the conventional model demonstrates extensive damage to the structural elements due to undesirable wall-to-frame interaction,which leads to a damage index of 0.78 and residual drifts of 0.42%under seismic loads.

关键词： precast wall-frame system rocking behavior post-tensioning O-shaped steel damper residual drift

Scattering by an array of parallel metallic carbon nanotubes

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Chinese Physics B 2013年第6期22卷 352-355页

作者： afshin Moradi Department of Nano Science Kermanshah University of TechnologyKermanshah 67178-63766Iran Department of Nano Science Institute for Studies in Theoretical Physics and Mathematics(IPM)Tehran 19395-5531Iran

The scattering of electromagnetic wave by an array of parallel metallic single-walled carbon nanotubes is investigated based on the boundary-value method. Electronic excitations over each nanotube surface are modeled as an infinitesimally thin cylindrical layer of the free-electron gas. The scattering cross section of both transverse magnetic （TM） and transverse electric （TE） uniform plane waves by the system at normal incidences is obtained.

关键词： carbon nanotube scattering TM mode TE mode

Electrostatic Surface Waves on Semi-Bounded Quantum Electron-Hole Semiconductor Plasmas

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Communications in Theoretical Physics 2017年第3期67卷 317-321页

作者： afshin Moradi Department of Engineering Physics Kermanshah University of Technology Kermanshah Iran

The electrostatic surface waves on semi-bounded quantum electron-hole semiconductor plasmas are studied within the framework of the quantum hydrodynamic model, including the electrons and holes quantum recoil effects,quantum statistical pressures of the plasma species, as well as exchange and correlation effects. The dispersion characteristics of surface electrostatic oscillations are investigated by using the typical values of Ga As, Ga Sb and Ga N semiconductors. Numerical results show the existence of one low-frequency branch due to the mass difference between the electrons and holes in addition to one high-frequency branch due to charge-separation effects.

关键词： electron-hole semiconductor plasma dispersion relation

Effect of copper slag recovery on hydrometallurgical cut-off grades considering environmental aspects

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Journal of Central South University 2016年第4期23卷 798-807页

作者： afshin AKBARI ESMAEIL RAHIMI Department of Mining Engineering Islamic Azad University-Central Tehran Branch Department of Mining Engineering Islamic Azad University-South Tehran Branch

Determining the hydrometallurgical cut-off grades specifies the destination of low grade materials and this is subjected to more benefits in mining. Copper production rate is considered as one of the fundamental issues in hydrometallurgical cut-off grades determination. Slags are remarked as one of the main sources of copper. It is not only regarded as a waste but also identified as another resource extracting base metals. Slags are characterized by copper high grade. Thus, slag copper recovery can be led to different cut-off grades and net present value(NPV). The current research scrutinizes the effect of slag recovery by both flotation and hydrometallurgical methods on the hydrometallurgical cut-off grades. For this purpose, the optimum cut-off grade algorithms of hydrometallurgical methods are developed by considering associated environmental parameters, incomes and also the costs. Then, their optimum amounts are calculated with NPV maximization as an objective function. The results indicate that considering slag copper recovery in the hydrometallurgical cut-off grade algorithms reduces the environmental costs caused by slag dumping and leads to more NPV by 9%.

关键词： hydrometallurgy cut-off grades low grade materials waste floatation slag copper recovery environmental parameters slag dumping NPV maximization

A Theoretical Model to Explain the Mechanism of Electromagnetic Wave Propagation Along Cylindrical Micelles

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Communications in Theoretical Physics 2013年第7期60卷 136-138页

作者： afshin Moradi Department of Nano Science Kermanshah University of Technology Department of Nano Science Institute for Studies in Theoretical Physics and Mathematics (IPM)

A theoretical model to explain the mechanism of the electromagnetic wave propagation in the quasi two-dimensional layer of counterions adjacent to the surface of a charged cylindrical membrane is presented. By using Maxwell and hydrodynamic equations with appropriate boundary conditions, general expression of dispersion relation is obtained for the electromagnetic wave with mixed TE and TM modes.

关键词： micelle electromagnetic wave dispersion relation

Dispersion Properties of High-and Low-Frequency Electrostatic Oscillations of Plasma Spheres:Application to the Metallic Nanoparticles

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Communications in Theoretical Physics 2015年第11期64卷 571-575页

作者： afshin Moradi Department of Engineering Physics Kermanshah University of Technology Department of Nano Sciences Institute for Studies in Theoretical Physics and Mathematics(IPM)

The dispersion properties of high-and low-frequency electrostatic oscillations of a spherical metallic plasma consisting of hot electrons and cold ions are *** main interest and the key first applications of this system are the spherical metal *** expressions of dispersion relations are obtained for the so-called surface and bulk plasmon waves,and surface and bulk ion-acoustic waves in spherical geometry,using hydrodynamic equations and Poisson equation with appropriate boundary *** results show that dispersion effects become large for metallic particles of small radii,particularly in the range of few nanometers.

关键词： metallic nanoparticle electrostatic oscillation di

Integrated feasibility analysis of shale inhibition property by utilization of pore pressure transmission equipment

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Petroleum Research 2018年第2期3卷 152-158页

作者： afshin Davarpanah Department of Petroleum Engineering Science and Research BranchIslamic Azad UniversityTehranIran

Regarding the widespread utilization of formate-based drilling fluids in numerous operational circumstances,petroleum industries are in urgent need of decreasing wellbore inefficiencies by improving the procedures ***,providing appropriate parameters such as safety,boosting the drilling speed and enrolling the proper procedure of optimizing performances of high activity water-sensitivity formation should be taken into *** objective of this comprehensive study is to apply experimental evaluation tests on the shale inhibitor fluids by using prepared plug samples from the studied field due to the administration of pore pressure transmission(henceforth,PPT)*** though,PPT equipment is not able to simulate all the mechanisms which are applied to different drilling fluids on the shale layers’stability,it will control such parameters like the penetration of fluid filtration through the formation that subsequently reduce the wellbore ***,the ubiquitous use formate fluid in drilling operations of exploratory oil wells in the studied field is successfully implemented to be addressed the current well inefficiencies adequately.

关键词： Pore pressure transmission Formate-base fluids Shale formation Shale inhibitors fluid Well inefficiencies

Design of a Level-3 electric vehicle charging station using a 1-MW solar system via the distributed maximum power point tracking technique

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Clean Energy 2024年第1期8卷 23-35页

作者： afshin Balal Michael Giesselmann Department of Electrical and Computer Engineering Texas Tech UniversityLubbockTX 79409USA

Solar power is mostly influenced by solar irradiation,weather conditions,solar array mismatches and partial shading ***,before installing solar arrays,it is necessary to simulate and determine the possible power *** power point tracking is needed in order to make sure that,at any time,the maximum power will be extracted from the photovoltaic ***,maximum power point tracking is not a suitable solution for mismatches and partial shading *** overcome the drawbacks of maximum power point tracking due to mismatches and shadows,distributed maximum power point tracking is util-ized in this *** solar farm can be distributed in different ways,including one DC-DC converter per group of modules or per *** this paper,distributed maximum power point tracking per module is implemented,which has the highest *** technology is applied to electric vehicles(EVs)that can be charged with a Level 3 charging station in<1 ***,the problem is that charging an EV in<1 hour puts a lot of stress on the power grid,and there is not always enough peak power reserve in the existing power grid to charge EVs at that ***,a Level 3(fast DC)EV charging station using a solar farm by implementing distributed maximum power point tracking is utilized to address this ***,the simulation result is reported using MATLAB®,LTSPICE and the System Advisor *** results show that the proposed 1-MW solar system will provide 5 MWh of power each day,which is enough to fully charge~120 EVs each ***,the use of the proposed photovoltaic system benefits the environment by removing a huge amount of greenhouse gases and hazardous *** example,instead of supplying EVs with power from coal-fired power plants,1989 pounds of CO_(2) will be eliminated from the air per hour.

关键词： electric vehicles(EVs) distributed maximum power point tracking solar farm DC fast-charging station step-up DC-DC converter System Advisor Model economic analysis

Thermal sensitivity of photonic crystal fibers in opto-electronic oscillators

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The Journal of China Universities of Posts and Telecommunications 2009年第4期16卷 1-6页

作者： afshin S. Daryoush Deptartment of ECE Drexel University

Stable opto-electronic oscillators （OEOs） are realized using long fiber delay lines and changes in the index of refraction of high quality factor delay line results in temperature sensitivity of OEOs. Temperature sensitivity of various OEOs is measured to compare index of refraction variation of standard （SMF-28） and photonic crystal fiber （PCF）. Both hollow-core （HC） and solid-core （SC） versions of PCF are quantified. SC-PCF exhibited a factor of three reductions in the rate of index of refraction change （about ＋4.7 ppm/℃） with temperature over SMF-28 （about 12 ppm/℃） based OEO. Although HC-PCF have a greater attenuation per unit length, but those fibers have demonstrated a negative rate of change （about - 0.6 ppm/℃） in the effective index of refraction with temperature and prospect of thermal stability in the OEO using passive techniques is great when a combination of HC-PCF and SMF-28 are employed as fiber delay lines.

关键词： opto-electronie oscillators frequency stability phase noise temperature sensitivity photonic crystal fiber hollow and solid core PCF

Dynamic and buckling analysis of polymer hybrid composite beam with variable thickness

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Applied Mathematics and Mechanics(English Edition) 2020年第5期41卷 785-804页

作者： S.afshin M.H.YAS Department of Mechanical Engineering Razi UniversityKermanshah 67149Iran

This work deals with a study of the dynamic and buckling analysis of polymer hybrid composite(PHC) beam. The beam has variable thickness and is reinforced by carbon nanotubes(CNTs) and nanoclay(NC) simultaneously. The governing equations are derived based on the first shear deformation theory(FSDT). A three-phase HalpinTsai approach is used to predict the mechanical properties of the PHC. We focus our attention on the effect of the simultaneous addition of NC and CNT on the vibration and buckling analysis of the PHC beam with variable thickness. Also a comparison study is done on the sensation of three impressive parameters including CNT, NC weight fractions, and the shape factor of fillers on the mechanical properties of PHC beams,as well as fundamental frequencies of free vibrations and critical buckling load. The results show that the increase of shape factor value, NC, and CNT weight fractions leads to considerable reinforcement in mechanical properties as well as increase of the dimensionless fundamental frequency and buckling load. The variation of CNT weight fraction on elastic modulus is more sensitive rather than shear modulus but the effect of NC weight fraction on elastic and shear moduli is fairly the same. The shape factor values more than the medium level do not affect the mechanical properties.

关键词： polymer hybrid composite(PHC) Halpin-Tsai carbon nanotube(CNT) nanoclay(NC) free vibration buckling load