The determination of the activation volume of diffusion is one of the best methods for the in­ vestigation of the relaxation of atoms or ions around defects. This paper discusses two experimental techniques for the determination of the activation volume for diffusion, by studying the effect of hydrostatic pressure on tracer diffusion and on ionic conductivity. Such experiments require a very cl...

This paper investigates whether durability indicators (DIs), more specifically transport properties, can be assessed by simple methods, e.g. direct experimental methods or indirect methods based on analytical formulas, for every type of concrete. First the results of electrical resistivity and apparent chloride diffusion coefficient obtained by direct measurement on a broad range of materials, ...

Accurate models of protein diffusion are important in a number of applications, including liquidliquid phase separation and growth of protein crystals for X-ray diffraction studies. In concentrated multicomponent protein systems, significant deviations from pseudobinary behavior can be expected. Rayleigh interferometry is used to measure the four elements (Dij)v of the ternary diffusion coeffic...

Methods which can be used to assess the chloride permeability of various types of concrete in a relatively short time are described. An electrical potential from 60-80 volt DC is applied either between a chloride solution ponded on a slab surface and the top of rebar mat, or between two faces at a core taken from a structure. The amount of chloride and sum of the electrical current which passes...

The neuronal K/Cl transporter KCC2 exports chloride ions and thereby influences the efficacy and polarity of GABA signaling in the brain. KCC2 is also critical for dendritic spine morphogenesis and the maintenance of glutamatergic transmission in cortical neurons. Because KCC2 plays a pivotal role in the function of central synapses, it is of particular importance to understand the cellular and...

The unidirectional fluxes of sodium, chloride, and of the bicarbonate and CO(2) 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 mv., serosal surface positive with respect to mucosal. The unidirectional sodium flux from mucosal to serosal surface was found ...

In service, cracks or microcracks are usually present in concrete as a result of several mechanisms, for example the drying shrinkage, thermal gradients, freezing-thawing cycles, alkali-aggregate reaction and external loading. It has been realized that cracking can significantly accelerate the ingress of chlorides into concrete since it provides preferential flow channels and allow more chlorid...