The major motive of the current investigation is to analyze an exact solution for an unsteady magnetohydrodynamics natural convective flow of a viscous incompressible electrically conducting non-gray optically thick fluid past an impulsively started infinite vertical plate with ramped wall temperature and concentration in the presence of radiation, diffusionthermo effect, and induced magnetic field. Laplace transform method is used to acquire the specific solutions of the dimensionless domain equations. The impact of various physical parameters on fluid velocities, temperature, concentration, and moreover on the rate of heat transfer, mass transfer, and skin friction at the wall are shown graphically. It is also found that the Dufour effect causes an increase in fluid velocity as well as temperature. The ramped condition influences the rise in Nusselt number. K E Y W O R D S concentration, diffusion-thermo effect (Dufour effect), heat transfer, induced magnetic field, mass flux, natural convection, ramped wall temperature

An unsteady convective MHD flow of water based Cu-nanofluid past an impulsively started infinite vertical plate embedded in porous medium including ramped velocity, temperature and concentration in the existence of diffusionthermo effect, radiation and chemical reaction has been investigated. The non-dimensional domain equations are computed by adopting Laplace transform technique. The impact of various pertinent parameters that are associated with the fluid velocity, temperature, concentration and moreover on skin friction coefficient, Nusselt number and Sherwood number has been represented graphically. It is figured out that, increase of Dufour effect causes to rise in both the momentum and temperature boundary layer. Further, it is ascertained that increase in the volume fraction of nanoparticles causes fall of velocity whereas it increases temperature together with the rate of heat transfer at the walls.

In the present study, we explore MHD water-based nanofluid flow past an impulsively started infinite vertical plate embedded in a porous medium, including ramped velocity and concentration in the presence of Hall effect, thermal radiation, chemical reaction, heat source/sink and thermal diffusion. The set of non-dimensional governing equations is computed utilising the Laplace transform method. The effect of different embedded parameters on velocity, temperature and concentration profiles have been plotted and graphically deliberated through physical interpretation. Variations of the Nusselt number, Sherwood number and skin friction are also studied. It is established that for higher values of nanoparticle volume fraction, the primary and secondary velocities and concentration of the fluid reduce. The temperature enhances by increasing the nanoparticle volume fraction. The thermal diffusion upsurges the fluid concentration. The rate of momentum transfer falls as Hall current parameter increases.