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A Spectral Method for the Electrohydrodynamic Flow in a Circular Cylindrical Conduit

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Chinese Annals of Mathematics,Series B 2015年第2期36卷 307-322页

作者： Mohsen MOGHTADAEI Hassan SABERI NIK Saeid ABBASBANDY Department of Mathematics Imam Khomeini International University young researchers and elite club Neyshabur Branch Islamic Azad University

This paper presents a combination of the hybrid spectral collocation technique and the spectral homotopy analysis method(SHAM for short) for solving the nonlinear boundary value problem(BVP for short) for the electrohydrodynamic flow of a fluid in an ion drag configuration in a circular cylindrical conduit. The accuracy of the present solution is found to be in excellent agreement with the previously published solution. The authors use an averaged residual error to find the optimal convergence-control parameters. Comparisons are made between SHAM generated results, results from literature and Matlab ode45 generated results, and good agreement is observed.

关键词： Spectral collocation Spectral homotopy analysis method Optimal convergence-control parameters Electrohydrodynamic flow

Graphene oxide based carbon composite as adsorbent for Hg removal:Preparation, characterization, kinetics and isotherm studies

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Chinese Journal of Chemical Engineering 2017年第9期25卷 1170-1175页

作者： Tayebeh Esfandiyari Navid Nasirizadeh Mohammad Dehghani Mohammad Hassan Ehrampoosh Department of Environmental Health Engineering Shaheed Sadoughi University of Medical Sciences young researchers and elite club Yazd Branch Islamic Azad University

The presence of Hg in the aqueous media is known to cause severe health issues in both humans and *** technologies and especially adsorbents have been applied for its removal. In this study, a graphene oxide–carbon composite(GO–CC) as a new adsorbent was prepared by sol gel procedure and characterized using field emission scanning electron microscopy, BET and EDX. The effects of different variables including solution p H, contact time, adsorbent dose and GO ratio in adsorbent matrix on the removal capacity of Hg were studied. The isotherm data correlated well with the Langmuir isotherm model. Further analysis recommended that the Hg^(2+) adsorption process is governed by the intra-particle and external mass transfer, in which the film diffusion was the rate restrictive step. The presented composite has maximum absorption capacity, q_(max) of 68.8 mg·g^(-1), which is comparable with carbon based adsorbent reported in the previous publications.

关键词： Adsorbent Mercury removal Sol gel Carbon composite

Effects of Anisotropy on Scalar Field Ghost Dark Energy and the Non-Equilibrium Thermodynamics in Fractal Cosmology

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Communications in Theoretical Physics 2017年第10期67卷 553-564页

作者： A.Najafi H.Hossienkhani young researchers & elite club Hamedan Branch Islamic Azad University Department of Physics Hamedan Branch Islamic Azad University

Since the fractal cosmology has been created in early universe, therefore their models were mostly isotropic. The majority of previous studies had been based on FRW universe, while in the early universe, the best model for describing fractal cosmology is actually the anisotropic universe. Therefore in this work, by assuming the anisotropic universe, the cosmological implications of ghost and generalized ghost dark energy models with dark matter in fractal cosmology has been discussed. Moreover, the different kinds of dark energy models such as quintessence and tachyon field, with the generalized ghost dark energy in fractal universe has been investigated. In addition, we have reconstructed the Hubble parameter, H, the energy density, p, the deceleration parameter, q, the equations of state parameter, wD, for both ghost and generalized ghost dark energy models. This correspondence allows us to reconstruct the potential and the dynamics of a fractal canonical scalar field according to the evolution of generalized ghost dark energy density. Eventually, thermodynamics of the cosmological apparent horizon in fractal cosmology was investigated and the validity of the Generalized second law of thermodynamics （GSLT） have been examined in an anisotropic universe. The results show the influence of the anisotropy on the OSLT of thermodynamics in a fractal cosmology.

关键词： anisotropic universe fractal cosmology ghost DE generalized ghost DE non-equilibrium ther-modynamics generalized second law

Nanoparticle migration effects on fully developed forced convection of TiO2-water nanofluid in a parallel plate microchannel

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Particuology 2016年第1期14卷 96-107页

作者： F. Hedayati G. Domairry young researchers and elite club Neyshabur Branch Islamic Azad University Neyshabur Iran Mechanical Engineering Department Babol University of Technology Babol lran

This study considers the forced convection of laminar TiO2-water nanofluid flow in a parallel plate microchannel. The small length scale associated with microchannels dictates the use of slip condition at the fuid-solid interface. The modified Buongiorno model was employed for the nanofiuid to fully account for the effects of non-uniform viscosity and thermal conductivity. The partial differential equa- tions associated with conservation laws were reduced to two-point ordinary boundary value differential equations before being numerically solved. Considering Brownian motion and thermophoresis, the effects of nanoparticle transport on concentration, velocity, and temperature profiles were analyzed for three different values of wall heat flux. To assess the efficiency of adding nanoparticles, the ratios of the pres- sure drop and the heat transfer coefficient of the nanofluid to that of the base fluid were studied in detail. From analyzing different heat flux ratios, one-sided heating was found to be most efficient at enhancing the heat transfer rate in the microchannel. Additionally, in the presence of the slip velocity, the increase in the value of the heat transfer coefficient for the nanofluid was smaller than that for the base fluid.

关键词： Nanofluid Microchannel Nanoparticles migration Slip velocity Brownian motion Thermophoresis

Efficient approaches of determining the motion of a spherical particle in a swirling fluid flow using weighted residual methods

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Particuology 2015年第6期13卷 68-74页

作者： Seiyed E. Ghasemi M. Vatani D.D. Ganji young researchers and elite club Qaemshahr Branch Islamic Azad University Qaemshahr lran Department of Mechanical Engineering Babol University of Technology Babol lran

The motion of a spherical particle released in a swirling fluid flow is studied employing the least-squares method and method of moments. The governing equations are obtained and solved employing the two methods. The accuracy of the results is examined against the results of a fourth-order Runge-Kutta numer- ical method. The effects of various parameters, namely the initial radius, initial radial velocity, initial angular velocity, and drag-to-inertia ratio, on the non-dimensional velocity profiles and particle position distribution are considered. The results show that the radial velocity increases over time while the angular velocity decreases, and that an increase in the initial radial velocity increases the particle radial distance and angular velocity but decreases the radial velocity profile.

关键词： Spherical particle Swirling flow Radial velocity Angular velocity Least-squares method Method of moments

Creep rupture assessment for Level-2 PSA of a 2-loop PWR： accounting for phenomenological uncertainties

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Nuclear Science and Techniques 2017年第8期28卷 117-125页

作者： Faramarz Yousefpour Seyed Mohsen Hoseyni Seyed Mojtaba Hoseyni Seyed Ali Hashemi Olia Kaveh Karimi Nuclear Science and Technology Research Institute TehranIran young researchers and elite club East Tehran BranchIslamic Azad University Tehran Iran

The Level-2 probabilistic safety assessment(PSA) of pressurized water reactors studies the possibility of creep rupture for major reactor coolant system components during the course of high pressure severe accident sequences. The present paper covers this technical issue and tries to quantify its associated phenomenological uncertainties for the development of Level-2 PSA. A framework is proposed for the formal quantification of uncertainties in the Level-2 PSA model of a PWR type nuclear power plant using an integrated deterministic and PSA approach. This is demonstrated for estimation of creep rupture failure probability in station blackout severe accident of a 2-loop PWR, which is the representative case for high pressure sequences. MELCOR 1.8.6 code is employed here as the deterministic tool for the assessment of physical phenomena in the course of accident. In addition, a MATLAB code is developed for quantification of the probabilistic part by treating the uncertainties through separation of aleatory and epistemic sources of *** probability for steam generator tube creep rupture is estimated at 0.17.

关键词：模型不确定性蠕变断裂 PSA 压水堆断裂评价二级现象学反应堆冷却剂系统

Analysis of nano droplet dynamics with various sphericities using efficient computational techniques

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Journal of Central South University 2017年第10期24卷 2353-2359页

作者： Ali Zolfagharian Milad Darzi S.E.Ghasemi School of Engineering Deakin University Department of Mechanical and Aerospace Engineering University of Missouri young researchers and elite club Sari BranchIslamic Azad University

Motion of a vertically falling nano droplet in incompressible Newtonian media with initial velocity is investigated. The instantaneous velocity and acceleration are carried out by using the variational iteration method(VIM) and homotopy perturbation method(HPM), which are analytical solution techniques. The obtained results are compared with Runge–Kutta method in order to verify the accuracy of the proposed methods. The results show that, the analytical solutions are in good agreement with each other and with the numerical solution. Also, the effects of sphericity(?) on the velocity and acceleration profiles of the nano droplet are explained. Moreover, the results demonstrate that the VIM-Padé and HPM-Padé are very effective in generating analytical solutions for even highly nonlinear problems.

关键词： nano droplet velocity acceleration homotopy perturbation method variational iteration method

Synthesis and Crystal Structure of 2-(4-Chlorophenyl)-1,4,5-triphenyl-1H-imidazole

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Chinese Journal of Structural Chemistry 2012年第4期31卷 574-576页

作者： Ali Mohammad Amani Kazem Barati young researchers club Shiraz BranchIslamic Azad University young researchers club Yasooj BranchIslamic Azad University

The compound 2-（4-chlorophenyl）-1,4,5-triphenyl-1H-imidazole（1,C27H19ClN2） has been synthesized and its crystal structure was determined by single-crystal X-ray *** crystal of 1 belongs to the triclinic system,space group P with a = 10.3350（19）,b = 10.238（2）,c = 11.201（2） ,α = 85.957（16）,β = 83.148（15）,γ = 66.467（15）°,V = 1078.5（4） 3,Mr = 406.89,Z = 2,F（000） = 422,Dc = 1.257 g/cm3,μ = 0.193 mm-1,T = 298（2） K,S = 1.092,R = 0.0702 and wR = *** imidazole ring system is planar and makes a dihedral angle of 40.3° with the chlorobenzene ring.

关键词： crystal structure imidazole triclinic system

Thermal-hydraulic and stress analysis of AP1000 reactor containment during LOCA in dry cooling mode

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Nuclear Science and Techniques 2017年第6期28卷 73-85页

作者： Sh.Sheykhi S.Talebi M.Soroush E.Masoumi Department of Energy Engineering and Physics Amirkabir University of Technology(Tehran Polytechnic) young researchers and elite club Islamic Azad UniversitySouth Tehran Branch

Some kinds of break in the reactor coolant system may cause the coolant to exit rapidly from the failure site,which leads to the loss of coolant accident(LOCA).In this paper,a stress analysis of an AP1000 reactor containment is performed in an LOCA,with the passive containment cooling system(PCCS) being available and not available for cooling the wall's *** variations in the mechanical properties of the wall's containment,including elastic modulus,strength,and stress,are analyzed using the ABAQUS code.A general two-phase model is applied for modeling thermal-hydraulic behavior inside the *** pressure and temperature from thermal-hydraulic models are considered as boundary conditions of the ABAQUS code to obtain distributions of temperature and stress across steel shell of the containment in the *** results indicate that if the PCCS fails,the peak pressure inside the containment exceeds the design ***,the stress would still be lower than the yield stress value,and no risk would threaten the integrity of the containment.

关键词： Two-phase flow LOCA Containment integrity AP1000 reactor