Biomedical subjects

M Paszkuta

Publications and source records attributed to M Paszkuta.

3 recordsLinked to original sources

PubMed2006

Thermodiffusional transport of electrolytes in compact clays.

The macroscopic Soret coefficient S(T) was measured for three porous media, namely mica, glass powder, and natural compact clay. At a mean temperature of T = 25 degrees C and with NaCl, S(T) for mica and glass powder was found to be equal to (3.1+/-0.7) x 10(-3) K(-1) and close to values for a free medium in agreement with theoretical predictions which are obtained under the assumption that the pressure gradient and the electric field are negligible on the pore scale. The main result is that for clay S(T) was found five times larger, presumably because of extra couplings with electrical phenomena. This latter measurement was confirmed by an independent technique based on the membrane potential.

Journal Article↗

PubMed2005

Electrokinetic phenomena in saturated compact clays.

The membrane potential, the pressure difference, and the concentration difference induced by an applied concentration gradient through samples of compact clay were measured as functions of sodium chloride concentration and of porosity. The results of some previous numerical predictions are recalled to be functions of a characteristic length scale which can be derived from conductivity and permeability. Generally, the experimental data were in agreement with these numerical predictions. Therefore, nondiagonal coupling coefficients can be derived with acceptable precision from the diagonal coefficients.

Journal Article↗

PubMed2003

Thermodiffusion in compact clays.

An experimental cell has been devised in order to measure the Soret coefficients in a compact clay, namely argilite, when a concentration difference of a binary mixture is applied simultaneously with a temperature difference. Temperature gradients have been imposed in the same direction as concentration gradients or in the opposite one. The sign of the Soret coefficients is related to the respective direction of these gradients. Generally, mass transfer was found to be enhanced by the Soret effect. Experimental values of the Soret coefficient are given.

Journal Article↗