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Biomedical subjects

M Tasaka

Publications and source records attributed to M Tasaka.

59 records · Page 4Linked to original sources
PubMed1978

Thermal membrane potential across charged membranes in 2-1 and 1-2 electrolyte solutions.

Measurements of thermal membrane potential across cation exchange membranes in MgCl2, CaCl2 and BaCl2 solutions and across anion exchange membranes in K2SO4, Na2SO4 and K2CO3 solutions were carried out. The magnitude of the thermal membrane potential for divalent counterions is lower than that for monovalent counterions. If the transport number of counterions in the membrane phase is unity, the slopes of the temperature coefficient of thermal membrane potential against logarithmic activities of counterion in the external solution are predicted to be--R/2F for 2-1 electrolytes with cation exchange membranes and R/2F for 1-2 electrolytes with anion exchange membranes, respectively.

Electrolytes↗
PubMed1977

Thermoosmosis through charged membranes.

Thermoosmosis through oxidized collodion and collodion-sulfonated polystyrene interpolyrene interpolymer membranes has been observed in KCl solutions of various concentrations. The effective temperature difference acting for thermoosmosis was determined by measuring the thermal membrane potential appearing on both sides of membrane. It was found that the velocity of thermoosmosis is proportional to the effective temperature difference and the proprtionality constant (themoosmotic coefficient) is a function of electrolyte concentration. The dependence of the thermoosmotic coefficient of charged membranes on the electrolyte concentration is found to have a characteristic feature.

Collodion↗
PubMed1976

Thermal membrane potential across charged membranes in NaCl-NH4Cl and LiCl-NH4Cl solutions.

Measurements of the thermal membrane potential across cation exchange membranes were carried out by using aqueous solutions containing two 1-1 electrolytes, with an anion in common. The same solution was used on both sides of the membrane. In all cases a good linear relationship was observed between the thermal membrane potential delta psi and the temperature difference delta T (in the range delta T = +/- 10 degrees C). Assuming that the activity of one cation is equal to that of another cation in the solutions and the sum of transport numbers of cations is unity, the plot of delta psi/delta T vs logarithmic activity of one cation is linear with a slope of R/F. These experimental results are in agreement with a theory presented previously. From the analysis of thermal membrane potential in mixtures of electrolytes it is obtained that the cross coefficient of cation-cation interaction in membranes is negative and about 6 to 9% of the main coefficient.

Ammonium Chloride↗
PubMed1975

Thermal membrane potential through charged membranes in electrolyte solutions.

Measurements of the thermal membrane potential across cation and anion exchange membranes were carried out by using the same solution of various 1-1 electrolytes on both sides of the membrane. In all cases a good linear relationship was observed between the thermal membrane potential increment psi and the temperature difference increment T. The slope of the linear plot varied with the concentration of the electrolyte. The value of increment psi/increment T versus logarithmic activity of the electrolyte plot was linear with a slope of +/- R/F if the transport number of counterion was unity. The magnitude of increment psi/increment T was independent of coion species but dependent on counterions. These experimental results are in agreement with a theory presented previously. The thermal membrane potential caused by the direct effect of temperature differences and that by the indirect effect arising from the changes in ionic and water chemical potentials due to the temperature difference are separately discussed.

Cations, Monovalent↗