where T is the temperature, p the pressure, and µ 1 and w 1 are the chemical potential and mass fraction of component 1, respectively. L ij are phenomenological Onsager coefficients that describe the proportionality between the thermodynamic forces and the fluxes that they induce. The auto-correlated properties L 11 and L QQ are the mass-mass and heat-heat phenomenological coefficients. The cross-correlated phenomenological coefficients L 1Q = L Q1 follow Onsager's reciprocity relations. On the other hand, experimentalists usually employ the following constitutive equations to describe heat and mass fluxes