检索结果-南通市图书馆

儿童Gaucher病神经元病变1H-MRS

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

国际医学放射学杂志 2014年第1期 85-86页

作者： A.A.K.A.Razek A.Abdalla N.A.Gaber A.Fathy a.megahed T.Barakat 高丽娟 Department of Diagnostic Radiology Mansoura Faculty of Medicine Mansoura University

目的评价儿童Gaucher病(NGD)1H-MRS的临床价值。方法本项前瞻性研究对21例连续的儿童NGD病例进行研究,其中急性期7例、慢性期14例,包括男13例、女

关键词：神经元病变 Gaucher病儿童中枢神经系统

Effect of slip velocity on Casson thin film flow and heat transfer due to unsteady stretching sheet in presence of variable heat flux and viscous dissipation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2015年第10期36卷 1273-1284页

作者： A.M.megahed Department of Mathematics Faculty of Science Benha University

The aim of the present paper is to study flow and heat transfer charac- teristics of a viscous Casson thin film flow over an unsteady stretching sheet subject to variable heat flux in the presence of slip velocity condition and viscous dissipation. The governing equations are partial differential equations. They are reduced to a set of highly nonlinear ordinary differential equations by suitable similarity transformations. The re- sulting similarity equations are solved numerically with a shooting method. Comparisons with previous works are macle, and the results are found to be in excellent agreement. In the present work, the effects of the unsteadiness parameter, the Casson parameter, the Eckert number, the slip velocity parameter, and the Prandtl number on flow and heat transfer characteristics are discussed. Also, the local skin-friction coefficient and the local Nusselt number at the stretching sheet are computed and discussed.

关键词： Casson thin film unsteady stretching sheet numerical solution slip effect,viscous dissipation variable heat flux

Carreau fluid flow due to nonlinearly stretching sheet with thermal radiation, heat flux, and variable conductivity

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2019年第11期40卷 1615-1624页

作者： A.M.megahed Department of Mathematics Faculty of Science Benha University

A sophisticated theoretical and mathematical model is *** is verified that this model can estimate and monitor the detailed behavior for the steady Carreau fluid flow past a nonlinear stretching surface and the predicted phenomena due to the presence of heat flux,thermal radiation,and viscous *** the fact that some properties of the fluid do not depend on the temperature,the fluid thermal conductivity is assumed to depend on the *** on accelerating the fluid elements,some of the kinetic energy for the fluid can be turned to the internal heating energy in the form of viscous dissipation *** contribution in this study is that a similar solution is obtained,in spite of the high nonlinearity of the Carreau model,especially,with the heat flux,variable conductivity,and viscous dissipation *** of the major significant findings of this study can be observed from the reduction in the fluid velocity with enhancing the Weissenberg ***,the increase in the sheet temperature is noted with increasing the Eckert number while the reverse behavior is observed for increasing both the radiation parameter and the conductivity ***,the accuracy and trust in the proposed numerical method are validated after benchmarking for our data onto the earlier results.

关键词： Carreau fluid nonlinearly stretching sheet variable heat flux variable conductivity

Slip flow and variable properties of viscoelastic fluid past a stretching surface embedded in a porous medium with heat generation

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2016年第4期23卷 991-999页

作者： Ahmed M.megahed Department of Mathematics Faculty of Science Benha University (13518)

This study examines theoretically and computationally the non-Newtonian boundary layer flow and heat transfer for a viscoelastic fluid over a stretching continuous sheet embedded in a porous medium with variable fluid properties, slip velocity, and internal heat generation/absorption. The flow in boundary layer is considered to be generated solely by the stretching of the sheet adjacent to porous medium with boundary wall slip condition. Highly nonlinear momentum and thermal boundary layer equations governing the flow and heat transfer are reduced to set of nonlinear ordinary differential equations by appropriate transformation. The resulting ODEs are successfully solved numerically with the help of shooting method. Graphical results are shown for non-dimensional velocities and temperature. The effects of heat generation/absorption parameter, the porous parameter, the viscoelastic parameter, velocity slip parameter, variable thermal conductivity and the Prandtl number on the flow and temperature profiles are presented. Moreover, the local skin-friction coefficient and Nusselt number are presented. Comparison of numerical results is made with the earlier published results under limiting cases.

关键词： viscoelastic fluid variable fluid properties slip velocity

Variable fluid properties and variable heat flux effects on the flow and heat transfer in a non-Newtonian Maxwell fluid over an unsteady stretching sheet with slip velocity

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2013年第9期22卷 480-485页

作者： Ahmed M. megahed Department of Mathematics Faculty of ScienceBenha University

The effects of variable fluid properties and variable heat flux on the flow and heat transfer of a non-Newtonian Maxwell fluid over an unsteady stretching sheet in the presence of slip velocity have been studied. The governing differential equations are transformed into a set of coupled non-linear ordinary differential equations and then solved with a numerical technique using appropriate boundary conditions for various physical parameters. The numerical solution for the governing non-linear boundary value problem is based on applying the fourth-order Runge-Kutta method coupled with the shooting technique over the entire range of physical parameters. The effects of various parameters like the viscosity parameter, thermal conductivity parameter, unsteadiness parameter, slip velocity parameter, the Deborah number, and the Prandtl number on the flow and temperature profiles as well as on the local skin-friction coefficient and the local Nusselt number are presented and discussed. Comparison of numerical results is made with the earlier published results under limiting cases.

关键词： Maxwell fluid unsteady stretching sheet variable fluid properties variable heat flux

Differential transformation method for studying flow and heat transfer due to stretching sheet embedded in porous medium with variable thickness, variable thermal conductivity,and thermal radiation

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2014年第11期35卷 1387-1400页

作者： M.M.KHADER A.M.megahed Department of Mathematics and Statistics College of Science Al-Imam Mohammad Ibn Saud Islamic University (IMSIU) Department of Mathematics Faculty of Science Benha University

This article presents a numerical solution for the flow of a Newtonian fluid over an impermeable stretching sheet embedded in a porous medium with the power law surface velocity and variable thickness in the presence of thermal radiation. The flow is caused by non-linear stretching of a sheet. Thermal conductivity of the fluid is assumed to vary linearly with temperature. The governing partial differential equations （PDEs） are transformed into a system of coupled non-linear ordinary differential equations （ODEs） with appropriate boundary conditions for various physical parameters. The remaining system of ODEs is solved numerically using a differential transformation method （DTM）. The effects of the porous parameter, the wall thickness parameter, the radiation parameter, the thermal conductivity parameter, and the Prandtl number on the flow and temperature profiles are presented. Moreover, the local skin-friction and the Nusselt numbers are presented. Comparison of the obtained numerical results is made with previously published results in some special cases, with good agreement. The results obtained in this paper confirm the idea that DTM is a powerful mathematical tool and can be applied to a large class of linear and non-linear problems in different fields of science and engineering.

关键词： Newtonian fluid stretching sheet differential transformation method(DTM) thermal radiation variable thermal conductivity variable thickness

Hydromagnetic Nanofluid Film Flow over a Stretching Sheet with Prescribed Heat Flux and Viscous Dissipation

在线全文

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2022年第5期18卷 1373-1388页

作者： Nourhan I.Ghoneim Ahmed M.megahed International Maritime College Oman(IMCO) Suhar322Sultanate of Oman Department of Mathematics Faculty of ScienceBenha UniversityBenha13518Egypt

Thermal radiative heat transfer through a thin horizontal liquid film of a Newtonian nanofluid subjected to a magnetic field is *** physical boundary conditions are a variable surface heat flux and a uniform concentration along the ***,viscous dissipation is present and concentration is assumed to be influenced by both thermophoresis and Brownian motion *** a similarity method to turn the underlying Partial differential equations into a set of ordinary differential equations(ODEs)and a shooting technique to solve these equations,the skin-friction coefficient,the Nusselt number,and the Sherwood number are *** other things,it is shown that large values of the thermal radiation heat transfer rate,thermal conductivity parameter,and the Brownian motion parameter can enhance the cooling of the sheet.

关键词： Nanofluid thin film variable heat flux viscous dissipation unsteady stretching sheet thermal radiation

Numerical Analysis of the Mixed Flow of a Non-Newtonian Fluid over a Stretching Sheet with Thermal Radiation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2023年第2期19卷 407-419页

作者： Nourhan I.Ghoneim Ahmed M.megahed Maritime Department-Marine Engineering International Maritime College Oman(IMCO)Suhar322Sultanate of Oman Department of Mathematics Faculty of ScienceBenha UniversityBenha13518Egypt

A mathematical model is elaborated for the laminar flow of an Eyring-Powell fluid over a stretching *** considered non-Newtonian fluid has Prandtl number larger than *** effects of variable fluid properties and heat generation/absorption are also *** balance equations for fluid flow are reduced to a set of ordinary differential equations through a similarity transformation and solved numerically using a Chebyshev spectral *** effect of various parameters on the rate of heat transfer in the thermal boundary regime is investigated,i.e.,thermal conductivity,the heat generation/absorption ratio and the mixed convection *** agreement appears to exist between theoretical predictions and the existing published results.

关键词： Porous medium Eyring-Powell fluid Chebyshev spectral method mixed convection thermal stratification

Melting phenomenon in magneto hydro-dynamics steady flow and heat transfer over a moving surface in the presence of thermal radiation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2013年第3期22卷 57-62页

作者： Reda G.Abdel-Rahman M.M.Khader Ahmed M.megahed Department of Mathematics Faculty of ScienceBenha University

The Lie group method is applied to present an analysis of the magneto hydro-dynamics（MHD） steady laminar flow and the heat transfer from a warm laminar liquid flow to a melting moving surface in the presence of thermal *** using the Lie group method,we have presented the transformation groups for the problem apart from the scaling *** application of this method reduces the partial differential equations（PDEs） with their boundary conditions governing the flow and heat transfer to a system of nonlinear ordinary differential equations（ODEs） with appropriate boundary *** resulting nonlinear system of ODEs is solved numerically using the implicit finite difference method（FDM）.The local skin-friction coefficients and the local Nusselt numbers for different physical parameters are presented in a table.

关键词： Lie group method magneto hydro-dynamics melting phenomenon Newtonian fluid radiation