molecular diffusion is one of the important contaminant transport mechanisms through soil and rocks. in this study the molecular diffusion coefficient of marl stone and sand stone from the urmia city landfill site was determined using the best fit method of the observed laboratory data and the predicted theoretical data. the marl stone and sand stone samples were tested under the conditions of ...

Polarographicdata are presented for the reduction of selenite ion in 3M sulfuric acid, 1M potassium chloride, and 1M ammonia-ammonium chloride. In these first two media two waves are obtained correspondingto the diffusion-controlled reduction of selenite ion to selenium amalgam and the adsorption of selenite ion on the mercury drop, respectively. One wave is obtained in ammonia-ammonium chlorid...

The influence of transmembrane ion fluxes on mycoplasma membrane potentials was studied. Fluorescence intensity of potential-sensitive carbocyanine dyes was calibrated vs. electric membrane potential. Potassium and sodium ion diffusion potentials significantly contributed to mycoplasma membrane potential. Chloride ions were obviously freely permeable across mycoplasma membranes. Under growth co...

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...

Abstract-A mathematical modeling was adopted to calculate the ferric ion diffusion coefficient based on the radiation induced magnetic resonance (MR) image intensity change in Fricke-agarose gels. A fast magnetic resonance imaging acquisition technique was employed to avoid the smearing of acquired data due to diffusion over an extended period of time. Our results showed that for a Fricke-agaro...

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 ...

This paper was conducted to study the behavior of lightweight concrete, incorporating local lightweight aggregate (LWA), in terms of chloride ion permeability at different ages. The effect of lightweight fine aggregate replacement by normal weight sand (0, 25, 50 and 75% by volume) was investigated. Constant level of silica fume content (10% by weight of cement) as an addition was also consider...

Plastic encapsulated microcircuits with aluminum triple track structures were exposed to mixed flowing gas conditions to simulate and accelerate possible environments during long-term storage. No increase in resistance was measured and no corrosion products were observed after 800 h of accelerated exposure. Further experimentation indicated that chloride gas reacts with surface moisture in micr...