Radiative transfer,medium porosity and collisional effects on thermal-convective instability

The problem of thermal-convective instability through the porous medium of a hydromagnetic composite mixture is studied to include the frictional effects with neutrals. A criterion for monotonic instability is derived. The radiative transfer effect is also considered on thermal-convective instability through the porous medium of the composite mixture. The criterion determining monotonic instability and depending on source functions is also derived.