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Characteristics of Positive Ions in the Sheath Region of magnetized Collisional Electronegative Discharges

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Plasma Science and Technology 2014年第6期16卷 552-556页

作者： m.m.hatami A.R.NIKNAm Physics Department of K.N.Toosi University of Technology Laser-Plasma Research Institute of Shahid Beheshti University G.C.

A hydrodynamic model is used to investigate the characteristics of positive ions in the sheath region of a low-pressure magnetized electronegative discharge. Positive ions are modeled as a cold fluid, while the electron and negative ion density distributions obey the Boltzmann distribution with two different temperatures. By taking into account the ion-neutral collision effect in the sheath region and assuming that the momentum transfer cross section has a power law dependence on the velocity of positive ions, the sheath formation criterion （modified Bohm＇s criterion） is derived and it is shown that there are specified maximum and minimum limits for the ion mach number m. Considering these two limits of m, the behaviors of electrostatic potential, charged particle density distributions and positive ion velocities in the sheath region are studied for different values of ion-neutral collision frequency.

关键词： electronegative plasma hydrodynamic model magnetized plasma sheath,Bohm's criterion

Effect of Ion Concentrations on the Characteristics of a multi-Component magnetized Plasma Sheath

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Plasma Science and Technology 2009年第6期11卷 642-646页

作者： m.m.hatami B.SHOKRI Laser-Plasma Research Institute of Shahid Beheshti University G.C.EvinTehranIran Physical Department and Laser-Plasma Research Institute of Shahid Beheshti University G.C.EvinTehranIran

A hydrodynamic approach is used to investigate a three-component magnetized plasma sheath which consists of electrons and two species of positive ions. Assuming a phase space of one-dimensional spatial coordinate system and three-dimensional velocity coordinate system, the effect of different concentrations of positive ion species on some characteristics of the plasma sheath such as the velocity and density distribution of positive ion species and the electrostatic potential of this region is investigated. The calculated results show that the increase in the density ratio of positive ion species causes a decrease in both the ion velocities and the electrostatic potential of the sheath region. Also, it is shown that in the sheath region of a magnetized plasma consisting of only one positive ion species the bumps of the net density of charged particles disappears much faster. In addition, three-dimensional velocity of each positive ion species in the sheath region is plotted for different concentrations of positive ion species.

关键词： magnetized plasma plasma and electropositive plasma sheath hydrodynamic equations multi-component sheath

Exact Solutions of the Dirac Equation for an Electron in a magnetic Field with Shape Invariant method

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Chinese Physics Letters 2008年第11期25卷 3848-3851页

作者： m. R. Setare O. hatami Department of Science University of Kurdistan Pasdaran Ave. Sanandaj Iran

Based on the shape invariance property we obtain exact solutions oI the Dirac equation for an electron moving in the presence of a certain varying magnetic field, then we also show its non-relativistic limit.

关键词： the power-law exponents precipitation durative abrupt precipitation change

Exact Solution of Klein-Gordon Equation for Charged Particle in magnetic Field with Shape Invariant method

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Communications in Theoretical Physics 2009年第6期51卷 1000-1002页

作者： m.R. Setare O. hatami Department of Science University of Kurdistan Pasdaran Ave. Sanandaj Iran

为面对某个变化移动的一个控告的粒子把三维的相对论的 Klein Gordon 方程的准确答案基于我们获得的形状不变性性质磁场，和我们也显示出它的非相对论的限制。

关键词：带电粒子运动精确解 Klein 磁场方程形状非相对论形不变性

Analysis of turbulent mHD Couette nanofluid flow and heat transfer using hybrid DTm-FDm

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Particuology 2016年第3期14卷 95-101页

作者： S. mosayebidorcheh m. Sheikholeslami m. hatami D.D. Ganji Young Researchers and Elite Club Najafabad Branch lslamicAzad University Ndjafabad Iran Department of mechanical Engineering Lenjan Branch Islamic Azad University lsfahan Iron Department of mechanical Engineering Babol University of Technology Babol Iran mechanical Engineering Department Engineering and Technical College Esfarayen University Esfarayen North Khorasan lran

Unsteady turbulent magnetohydrodynamic nanofluid hydrothermal treatment is studied. The zero- equation turbulence model is used to simulate turbulent flow. The modeling results obtained by applying the hybrid differential transformation method-finite difference method to solve this problem confirm its viability. An analytical procedure is used for finding the effects of the problem parameters. Results indicate that the average Nusselt number over the lower plate depends linearly on volume fraction of nanofluid, Hall parameter, turbulent Eckert number, and Reynolds number whereas it is inversely proportional on the Hartmann number and the turbulent parameter.

关键词： Turbulent Hall effect Hybrid DTm-FDm Nanofluid magnetohydrodynarnic couette flow

Optimization of the fuel rod＇s arrangement cooled by turbulentnanofluids flow in pressurized water reactor (PWR)

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Chinese Journal of Chemical Engineering 2017年第6期25卷 722-731页

作者： m. hatami mJ.Z. Ganfi I. Sohrabiasl D. Jing International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi'anJiaotong University Xi'an 710049 China Department of mechanical Engineering Esfarayen University of Technology Esfarayen North Khorasan lran Department of Renewable Energies Engineering Faculty of New Sdences & Technologies University of Tehran Tehran lran Department of mechanical Engineering Babol University of Technology Babol lran

In this paper, response surface methodology(RSm) based on central composite design(CCD) is applied to obtain an optimization design for the fuel rod's diameter and distance cooled by turbulent Al_2O_3–water nanofluid for a typical pressurized water reactor(PWR). Fuel rods and nanofluid flow between them are simulated 3D using computational fluid dynamics(CFD) by ANSYS-FLUNET package software. The RNG k–ε model is used to simulate turbulent nanofluid flow between the rods. The effect of different nanoparticles concentration is also investigated on the Nusselt number from heat transfer efficiency view point. Results reveal that when distance parameter(a) is in the minimum level and diameter parameter(r) is in the maximum possible level, cooling the rods will be better due to higher Nusselt number in this situation. Also, using the different nanoparticles on the cooling process confirms that Al_2O_3 averagely 17% and TiO_2 10% improve the Nusselt numbers.

关键词： Optimization Fuel rods Nanofluid Pressurized water reactor

Enhanced efficiency in Concentrated Parabolic Solar Collector(CPSC) with a porous absorber tube filled with metal nanoparticle suspension

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Green Energy & Environment 2018年第2期3卷 129-137页

作者： mohammad hatami Jiafeng Geng Dengwei Jing mechanical Engineering Department Esfarayen University of Technology (EUT) International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power EngineeringXi'an Jiaotong University

In this study, effects of different nanoparticles and porosity of absorber tube on the performance of a Concentrating Parabolic Solar Collector(CPSC) were investigated. A section of porous-filled absorber tube was modeled as a semi-circular cavity under the solar radiation which is filled by nanofluids and the governing equations were solved by FlexPDE numerical software. The effect of four physical parameters, nanoparticles type, nanoparticles volume fraction(φ), Darcy number(Da) and Rayleigh number(Ra), on the Nusselt number(Nu) was discussed. It turns out that Cu nanoparticle is the most suitable one for such solar collectors, compared to the commonly used Fe_3O_4, Al_2O_3, TiO_*** the increased addition of Cu nanoparticles all the parameters φ, Da and Ra shows a significant increase against the Nu, indicates the enhanced heat transfer in such cases. As a result, low concentration of Cu nanoparticle suspension combined with porous matrix was supposed to be beneficial for the performance enhancement of concentrating parabolic solar collector.

关键词： Concentrating parabolic solar collector Porous absorber tube Nanofluid Nusselt number Finite Element method

A basal area increment model for individual trees in mixed continuous cover forests in Iranian Caspian forests

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Journal of Forestry Research 2020年第1期31卷 99-106页

作者： Nishtman hatami Peter Lohmander mohammad Hadi moayeri Soleiman mohammadi Limaei Department of Forestry Faculty of Natural ResourcesGorgan University of Agricultural Sciences and Natural ResourcesP.O.Box 386mGorganIran Optimal Solutions in Cooperation with Linnaeus University Va¨xjo¨Sweden Department of Forestry Faculty of Natural ResourcesUniversity of GuilanP.O.Box 1144Sowmeh SaraIran

The aim of this study was to develop and test a new basal area growth model in mixed species continuous cover forests in northern *** 421 core samples from 6 main species in the forest area to develop our growth *** each plot,we measured variables such as total tree height(m),diameter at breast height(DBH)(cm)and basal area of larger trees as cumulative basal areas of trees(GCUm)ofDBH[5 *** empirical data were analyzed using regression *** was a statistically significant nonlinear function between the annual basal area increment,as the dependent variable,and the basal area of the individual trees and competition as explanatory *** area from the largest trees,was circular plot with area of 0.1 *** was estimated for trees of DBH>5 ***,we investigated the dependencies of diameter growth of different species on stand density at different levels of competition,and diameter development of individual trees through *** results indicate that competition caused by larger neighborhood trees has a negative effect on *** addition,the maximum diameter increment is affected by competition ***,the maximum diameter increment of species occurs when the trees are about 35–40 cm in dense-forest(40 to 0 m^2 per ha)and when the trees are about 60 to 70 cm in very dense forest(60 to 0 m^2 per ha)which is more likely to Caspian natural forests with high level density due to uneven-aged composition of stands.

关键词： Individual-tree model Iranian Caspian forests Continuous cover forestry mixed stands Uneven-aged management

硫化铅纳米粒子的三阶非线性光学特性研究(英文)

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光学精密工程 2011年第9期19卷 2242-2246页

作者： majles Ara m H Afsary m.hatami m malekfar R Boroojerdian P Department of Physics TarbiatMoallem University Department of Physics TarbiatModares University Plasma Physics Research Center Science and Research BranchIslamic Azad University

针对硫化铅(PbS)特殊的三阶非线性光学特性,本文在水溶液里合成了PbS纳米粒子。紫外-可见光谱显示,由于使用了封端剂,合成的样品更加稳定。用紫外-可见吸收光谱和X射线衍射斑研究了PbS纳米粒子的特性,结果表明,由于纳米粒子尺寸减小,其... 详细信息

针对硫化铅(PbS)特殊的三阶非线性光学特性,本文在水溶液里合成了PbS纳米粒子。紫外-可见光谱显示,由于使用了封端剂,合成的样品更加稳定。用紫外-可见吸收光谱和X射线衍射斑研究了PbS纳米粒子的特性,结果表明,由于纳米粒子尺寸减小,其吸收光谱显示极大的蓝移。利用Scherre方程估计PbS粒子的平均粒径约为8.2nm。最后,基于使用了632.8nm He-Ne激光器的用单光束Z-扫描技术研究了所制备的纳米粒子的非线性光学特性。对3种具有不同摩尔数的样品的测试表明,计算所得的非线性折射率在-10-7(cm2/W)量级。

关键词：硫化铅纳米粒子 Z-扫描非线性光学特性