In this investigation, the magnetohydrodynamic pulsatile flow of Casson nanofluid through a vertical channel embedded in porous medium with thermal radiation and heat generation/absorption has been analyzed using Buongiorno model. The influence of viscous and Joules dissipations are taken into account. The governing coupled partial differential equations are reduced to ordinary differential equations using perturbation scheme and then solved numerically by using Runge-Kutta fourth order technique along with shooting method. The impact of various emerging parameters on velocity, temperature, nanoparticles concentration, Nusselt number and Sherwood number distributions are analyzed in detail. Analysis indicates that the temperature distribution increases for a given increase in Brownian motion parameter and thermophoresis parameter, while it decreases with an increase in Hartmann number. Further, the nanoparticles concentration distribution decreases with an increase in the chemical reaction parameter and the Lewis number, while it increases for a given increase in the Brownian motion parameter.

This paper presents a two dimensional asymptotic model of counterflow diffusion flame in the presence of radiation heat loss. The fuel and oxidizer, respectively, are injected from left and right hand side of the flame. The effects of burning rate, Lewis and Damkohler number on the structure and extinction of the flame is studied using perturbation method. To do so, the structure of the flame is considered to be composed of reaction zone with a thickness of O(ε) and radiation heat loss zone, of O(δ) thickness, that sandwiches the reaction zone. The effect of burning rate is illustrated by burning pre-exponential parameter, B. It is found that with the increase of the parameter, the flame temperature is also increased, and flame location moves toward the fuel side. In addition, the variation of Lewis number of fuel and oxidizer has a significant effect on the location and temperature of the flame.