زبانوں کی تہذیبی اہمیت عربی زبان و قرآن حکیم: اہمیت و کردار

Languages are considered God-gifted and human being is far superior in linguistic skills as compared to other creatures. Language is associated with the civilization and demise of a language leads to death of that civilization. The words and phrases of a language are the outcome of specific epistemological environment of a civilization and cannot be used in the same mining in any other language.

Nonlinear Stagnation Point Flows Induced by Riga Plate

This thesis focuses on the characteristics of two-dimensional and incompressible stagnation point flows of Newtonian/ non-Newtonian fluids induced by Riga plate. It is the combination of alternative magnets and electrodes and it is especially used for the flows of those fluids having weak electrical conductivity. Here, only orthogonal stagnation point flows are discussed comprehensively. Linear and nonlinear stretching of the plate are considered with constant and variable thickness respectively. Fourier’s law of heat conduction/Cattaneo-Christov heat flux model is implemented to uncover the features of heat transport. Heat generation/absorption and viscous dissipation are modeled with Cattaneo-Christov heat flux model for the first time. Further, melting heat transfer and convective boundary conditions are investigated mathematically for the first time with thermal stratification. Characteristics of Polystyrene-water and Polystyrene-kerosene oil nanofluids are studied also for the first time. Other physical phenomena such as, velocity slip, thermal slip, Darcy-Forchheimer porous medium, nonlinear mixed convection, thermal radiation and homogeneous-heterogeneous chemical reactions are encountered to analyze the fluid flows with heat and mass transfer. Viscous, second grade and Powell-Eyring fluids are used to study the stagnation point flow induced by Riga plate. The governing nonlinear partial differential equations are converted into nonlinear ordinary differential equations by implementing suitable transformations. Approximate solutions are computed through homotopic/numerical techniques. Graphical behaviors of velocity, temperature and concentration profiles are studied comprehensively corresponding to various physical parameters. Skin friction, Nusselt number and entropy generation parameter are illustrated and discussed through various physical parameters.