A procedure is described for the calculation of activity and osmotic coefficients which is based upon a knowledge of the equilibria in solutl.on and assumed si.ngle-ion activity coefficients. The procedure permits one to introduce chemical equilibria of various types (ion-pairing, complexation, hydration, and hydrolysis) into a model which can be used to calculate values of the excess Gibbs ene...

A computer simulation of osmotic processes has been developed. Several experimental setups are graphically simulated and may be freely selected by the user. The simulation analyzes the basic factors which determine the osmotic pressure and volume flow of a solution (e.g. concentration, temperature, activity coefficient, Staverman's coefficient and external pressure). The program was written in ...

Osmosis is usually taught from the point of view of the osmotic pressure developed when solutions of different concentrations of solute are separated by an ideal semipermeable membrane. The osmotic pressure is defined at equilibrium when there is no net flow, and it takes some time to reach this equilibrium. Although the osmotic pressure is certainly important, teaching only this point of view ...

Step additions of small hydrophilic solutes to the perfusate of isolated dog lungs produce weight changes (Vargas-Johnson). The product: (observed reflection coefficient) times (observed filtration coefficient) for the lung endothelial barrier is obtained from the initial weight slope per unit osmolality change. The observed filtration coefficient determined from the sustained constant weight s...

We report on the brain diffusion MR imaging findings in a neonate with severe hypernatremic dehydration, which resulted in cerebral edema (osmotic edema) and in apparent diffusion coefficient decrease, despite a careful and slow rehydration. This report provides in vivo insight into nervous cell response to osmotic challenge.

The osmotic coefficient of B-DNA in water may, in moderately dilute solutions, deviate as much as 100 % from predictions based on a simple ’counterion condensation’ theory. We determine the results for osmotic properties via a cell model description of the ionic atmosphere near a cylindrical polyelectrolyte. The cell model predictions for the osmotic properties disagree with predictions based o...