1. THERMAL RADIATION EFFECT ON FULLY DEVELOPED FREE CONVECTION IN A VERTICAL RECTANGULAR DUCT. Authors: T. GROŞAN, T. MAHMOOD, I. POP.2. RADIATION AND VARIABLE VISCOSITY EFFECTS IN FORCED CONVECTION FROM A HORIZONTAL PLATE EMBEDDED IN A POROUS MEDIUM. Authors: I. POP, S.R. POP, T. GROŞAN.