Mathematical models of a diffusion-convection in porous media are derived from the homogenization theory. We start with the mathematical model on the microscopic level. which consist of the Stokes system for a weakly compressible viscous liquid occupying a pore space. coupled with a diffusion-convection equation for the admixture. https://www.chiggate.com/3m-speedglas-9002nc-welding-helmet-fashion/