Dynamic neutron radiography observations of water migration in porous media

Neutron Radiography Studies of Water Self-Diffusion in Porous Medium

“…The studies were performed on a sample of fired clay brick of effective porosity ∼ 30% (36% as determined by destructive mercury intrusion), of the same kind as used previously as the medium in spontaneous imbibition studies [12][13][14]. The effective capillary radius of the sample as determined from the rate of water imbibition was ∼ 5.5 nm.…”

“…The neutron radiograms were recorded for over 80 h with the dynamical neutron radiography station at MARIA reactor [12,13]. In first few hours after filling the H 2 O container with the liquid we observed in the radiograms a dark region that emerged at the H 2 O immersed end and progressed slowly towards the sample's end in contact with D 2 O (Fig.…”

“…The dependence of the volumetric content of ordinary water θ(x, t) at some time t on the position x along the axis was determined according to the standard procedure [12,13]:…”

“…Our first observations of the water self-diffusion carried out with the neutron radiography yielded only rough estimate of the self-diffusion coefficient at room temperature [12]. In the present work the system studied was held in stabilized conditions and the measurements were performed at 30, 35, 40, 45, and 50…”

Effect of Gravitation on Water Migration in Granular Media

“…In our studies the neutron radiography technique was used, which has been proved to be perfect for determination of the wetting front motion and water distribution inside the rigid and granular porous media [7][8][9][10][11][12]. We hope that the results of our experiments with simple granular structures will help in planning future research on subtleties of water migration in granular media.…”