Figure 6.
The two-panel schematic depicts experimental flow configurations for concentration measurements. In panel a, a central rectangular sample is connected by tubing to a left reservoir labelled C in and a right reservoir labelled C out, indicating inflow and outflow concentration measurement during through flow. In panel b, a central rectangular sample is connected by tubing only to a reservoir labelled C in, indicating an inlet concentration condition without an outlet concentration reservoir shown. The tubing paths illustrate the direction of fluid connection between reservoirs and the central sample in each configuration.Schematic description of two methodologies commonly used to obtain diffusion coefficients in clay materials: (a) through-diffusion and (b) in-diffusion (after Bourg and Tournassat, 2015)