The standard theory of ideal gases ignores the interaction of the gas particles with the thermal radiation (photon gas) that fills the otherwise vacuum space between them. This is an unphysical feature of the theory since every material in this universe, and hence also the particles of a gas, absorbs and radiates thermal energy. The interaction with the thermal radiation that is contained withi...

At present, a number of models are available describing the adsorption of a fluid in a random porous medium. In this paper, some exact and analytical results are presented. All the results are obtained for an ideal gas adsorbed in various porous matrices. It is shown that the calculations are not always trivial. In some cases of complicated matrices, it is impossible to obtain any analytical re...