The unidirectional fluxes of sodium, chloride, and of the bicarbonate and CO2 pair were determined across the isolated large intestine of the bullfrog, Rana catesbiana. The isolated large intestine of the frog is characterized by a mean transmembrane potential of 45 my., serosal surface positive with respect to mucosal. The unidirectional sodium flux from mucosal to serosal surface was found to...

Diffusion exchange of dextran with molecular weights 4.4 and 77 kDa through polyelectrolyte multilayer (PEM) hollow capsules consisting of four bilayers of polystyrene sulfonate/polydiallyldimethylammonium chloride has been investigated using two-dimensional nuclear-magnetic-resonance methods: diffusion-diffusion exchange spectroscopy (DEXSY) and diffusion-relaxation correlation spectroscopy (D...

Organotin cations (R3Sn+) form electrically neutral ion pairs with monovalent anions. It is demonstrated that the tin derivatives induce exchange diffusion of chloride in red cells and resealed ghosts, without any detectable increase of membrane permeability to net movements of chloride ions. The obligatory anion exchange is believed to be due to the permeation of electroneural ion pairs, where...

The dynamics of water and chloride counter ions (Cl) in single unit cells of orthorhombic and tetragonal hen egg white lysozyme lattices are investigated by 5 ns molecular dynamics simulations. The electrostatic interaction inside the crystal channel significantly influences the diffusion of chloride ions. The corresponding diffusion constants of Cl calculated by averaging over all ions during ...

A new method is developed for the removal of nitrate ions from water. Nitrate ions can be removed from water almost completely, with a mobile carrier, by counter-transport of chloride ions through a supported liquid membrane. The transport characteristics of this process, in which the water phases are flowing parallel to flat membranes, are described. The results show that depending on the expe...

Self-compacting concrete (SCC) demands more studies of durability at higher temperatures when subjected to more aggressive environments in comparison to the conventional vibrated concrete (CC). This work aims at presenting results of durability indicators of SCC and CC, having the same water/binder relations and constituents. The applied methodologies were electrical resistivity, diffusion of c...

The corrosion behaviour of copper was studied in anoxic solutions containing different concentrations of sulphide (10–10 mol L) and chloride (0?1–5 mol L) under stagnant and controlled convective conditions. The main determinants of the structure and properties of the copper sulphide (Cu2S) films formed are the rate of sulphide transport to the surface relative to the rate of its interfacial re...

Three new heterogemini sulfobetaines and their chloride salts were synthesised. The interfacial activities of the obtained chlorides in aqueous solution were studied by equilibrium and dynamic surface tension measurements. The critical micelle concentration, surface excess concentration, minimum area per surfactant molecule and standard Gibbs energy of adsorption as well as micelle lifetime and...

Abstract Post-cast application of hydrophobic agents onto hardened concrete is successful at reducing external ion diffusion into cement paste, this work examines pre-cast admixtures in fresh concrete. Concretes, with water to ratios (w/c) 0.45 and 0.50 (CEM I; low C3A), were mixed. Adding alkyltrialkoxysilane or triacylglycerol ranging from 1 3 wt%cem these concretes evaluated. Increasing the ...