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Uddin M.J.,Universiti Sains Malaysia | Uddin M.J.,Bangladesh American International University | Khan W.A.,National University of Sciences and Technology | Ismail A.I.,Universiti Sains Malaysia
PLoS ONE | Year: 2012

Steady two dimensional MHD laminar free convective boundary layer flows of an electrically conducting Newtonian nanofluid over a solid stationary vertical plate in a quiescent fluid taking into account the Newtonian heating boundary condition is investigated numerically. A magnetic field can be used to control the motion of an electrically conducting fluid in micro/nano scale systems used for transportation of fluid. The transport equations along with the boundary conditions are first converted into dimensionless form and then using linear group of transformations, the similarity governing equations are developed. The transformed equations are solved numerically using the Runge-Kutta-Fehlberg fourth-fifth order method with shooting technique. The effects of different controlling parameters, namely, Lewis number, Prandtl number, buoyancy ratio, thermophoresis, Brownian motion, magnetic field and Newtonian heating on the flow and heat transfer are investigated. The numerical results for the dimensionless axial velocity, temperature and nanoparticle volume fraction as well as the reduced Nusselt and Sherwood number have been presented graphically and discussed. It is found that the rate of heat and mass transfer increase as Newtonian heating parameter increases. The dimensionless velocity and temperature distributions increase with the increase of Newtonian heating parameter. The results of the reduced heat transfer rate is compared for convective heating boundary condition and found an excellent agreement. © 2012 Uddin et al.

Rahman M.M.,University of Southern Queensland | Mamun S.A.K.,Bangladesh American International University
Renewable and Sustainable Energy Reviews | Year: 2016

This study investigates the existence of either energy-led growth hypothesis or trade-led growth in Australia for a 53-year period (1960–2012) using a multivariate extended growth model. The econometric techniques used in this study are Autoregressive Distributed Lag (ARDL) bounds testing approach of cointegration, the Granger Causality Test and Impulse Response Functions. The study finds the evidence of no long-run cointegration between the variables of interest. Granger causality test confirms bidirectional causal relationship between international trade and per capita GDP growth, but does not find any Granger causal relationship between energy use and per capita GDP growth. Thus, this study provides an evidence of the trade-led growth hypothesis over the energy-led growth hypothesis for the Australian macroeconomy. © 2016 Elsevier Ltd

Maleque K.A.,Bangladesh American International University
Chemical Engineering Communications | Year: 2010

The present study investigates the effects of mixed temperature- and depth-dependent viscosity and Hall current on an unsteady flow of an incompressible electrically conducting fluid on a rotating disk in the presence of a uniform magnetic field. We assume that the fluid viscosity strongly depends on temperature and depth, which may be directly applicable to the earth's mantle and a uniform mid-ocean ridge basalt reservoir in whole mantle flow. The system of axial symmetric nonlinear partial differential equations governing the unsteady flow and heat transfer is written in cylindrical polar coordinates and reduced to nonlinear ordinary differential equations by introducing suitable similarity parameters. Solutions for the flow and temperature fields are obtained numerically assuming large Prandtl number by using Runge-Kutta and shooting methods. The nature of radial, tangential, and axial velocities and temperature in the presence of a uniform magnetic field is presented for changing various nondimensional parameters at different layers of the medium. The coefficients of skin frictions and the rate of heat transfer are calculated at different parameters. Comparison has been made for steady flow (C=0) and shows excellent agreement with Sparrow and Gregg (1959), hence encouragement for the use of the present numerical computations. © Taylor & Francis Group, LLC.

Iqbal Md.R.A.,Bangladesh American International University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012

Ensemble methods have become very well known for being powerful pattern recognition algorithms capable of achieving high accuracy. However, Ensemble methods produces learners that are not comprehensible or transferable thus making them unsuitable for tasks that require a rational justification for making a decision. Rule Extraction methods can resolve this limitation by extracting comprehensible rules from a trained ensembles of classifiers. In this paper, we present an algorithm called REEMTIC that uses a symbolic learning algorithm (Decision Tree) on each underlying classifier of the ensemble and combines them. Experiments and theoretical analysis show REEMTIC generates highly accurate rules that closely approximates the Ensemble Learned Model. © 2012 Springer-Verlag.

A local similarity solution of unsteady MHD natural convection heat and mass transfer boundary layer flow past a flat porous plate within the presence of thermal radiation is investigated. The effects of exothermic and endothermic chemical reactions with Arrhenius activation energy on the velocity, temperature, and concentration are also studied in this paper. The governing partial differential equations are reduced to ordinary differential equations by introducing locally similarity transformation (Maleque (2010)). Numerical solutions to the reduced nonlinear similarity equations are then obtained by adopting Runge-Kutta and shooting methods using the Nachtsheim-Swigert iteration technique. The results of the numerical solution are obtained for both steady and unsteady cases then presented graphically in the form of velocity, temperature, and concentration profiles. Comparison has been made for steady flow (A = 0) and shows excellent agreement with Bestman (1990), hence encouragement for the use of the present computations. © 2013 Kh. Abdul Maleque.

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