A how-to approach for estimation of surface/Stern potentials considering ionic size and polarization

Based on the effects of ionic volume in Stern layer and polarization in diffuse layer, the relationship between surface potential and Stern potential is quantified.

Comparison of Endolymph Cross-Sectional Area Measured Histologically with that Measured in Vivo with an Ionic Volume Marker

In order to establish how endolymph volume is regulated, it is essential to be able to measure endolymph volume or cross-sectional area in vivo. We have developed methods to accomplish this by injecting the volume marker ion hexafluoroarsenate (AsF6) into endolymph by iontophoresis. For an injection at a constant rate, the endolymph concentration is inversely dependent on the cross-sectional area of the scala into which injection occurred. Marker concentrations were monitored by inserting ion-selective microelectrodes into endolymph near the injection site. In a previous study we quantified the degree of hydrops in animals following ablation of the endolymphatic sac. In the present study we validated the technique by comparing the endolymphatic cross-sectional area measured in vivo with AsF6 with that measured by established histologic procedures. The correlation between the two measures was good, with a coefficient of .903, although the area measured histologically was a little lower than that measured in vivo.

The viscosity of concentrated electrolyte solutions. II. Temperature dependence

The temperature dependence of the viscosity of concentrated aqueous electrolyte solutions has been explained in terms of the temperature dependence of the E and V parameters of an equation previously developed for the viscosity of such solutions. Analysis of the V parameters for the alkali halide and ammonium halide salts leads to absolute ionic hydration numbers. The temperature dependence of these hydration numbers reveals two types of ionic behaviour: structure making ions and structure breaking ions. The Gourary–Adrian scale of ionic radii is found to be more consistent with these data and the temperature dependence than the Pauling ionic radii scale.Analysis of the E parameters leads to the ionic free energy of activation parameters for viscous flow of the ions. The Furth model for hole formation in a liquid is found to correlate these ionic free energy values with the absolute ionic volume parameters obtained from the analysis of the V parameter for all salts. Again the ions are found to break into structure making and structure breaking groups in terms of the surface tension values for the water about the hydrated ions.