Thermogravitational separation in porous vertical and horizontal cylindrical annular cells saturated by a binary mixture.

In this paper, analytical and numerical studies of species separation in vertical and horizontal porous, cylindrical annular cells were presented. The binary fluid, saturating the porous medium, is a water-ethanol mixture. The thickness e of the horizontal and vertical columns is equal to [Formula: see text], where [Formula: see text] and [Formula: see text] are, respectively, the internal and the external radii.

Electrolyte stability in a nanochannel with charge regulation.

The stability of an electrolyte confined in one dimension between two solid surfaces is analyzed theoretically in the case where overlapping double layers produce nontrivial interactions. Within the Poisson-Boltzmann-Nernst-Planck description of the electrostatic interaction and transport of electrical charges, the presence of Stern layers can enrich the set of possible solutions. Our analytical and numerical study of the stability properties of the trivial state of this system identified an instability to a new antisymmetric state.