-Monte Carlo simulations based on tested water-water, cation-water, and water-clay potential functions were applied to calculate radial distribution functions for O-O, O-H and H-H spatial correlations in the interlayer region of the two-layer hydrates of Naand K-montmorillonite. The simulated radial distribution functions then were used to compute the total radial distribution function for inte...

a r t i c l e i n f o In Soil Taxonomy three diagnostic subsurface horizons reflect clay enrichment: the argillic, kandic, and natric horizons. Clay illuviation is recognized in Soil Taxonomy at some level in 10 of the 12 orders, including the percent of the soil series in the USA contain taxonomically defined clay-enriched horizons. However, many other soils contain Bt horizons that do not qua...

Numerical limit analyses have been used to evaluate the stability of the 17th Street Canal I-wall levee during Hurricane Katrina. The potential formation of a water-filled gap along the canal-side soil-wall interface at failure is included in both the lowerand upper-bound formulations. The analyses replicate published two-dimensional (2D) cross sections and soil properties developed in forensic...

An in-situ Porewater Chemistry (PC) experiment in the Opalinus Clay formation was carried out at the Mont Terri underground rock laboratory (Jura Mountains, Switzerland) for a period of five years. A traced water with a composition close to that expected in the formation was continuously circulated and monitored in a packed-off borehole to achieve diffusive equilibration. An unwanted microbial ...

Natural gas production from the Marcellus Shale formation has significantly changed energy landscape in recent years. Accidental release, including spills, leakage, and seepage of the Marcellus Shale flow back and produced waters can impose risks on natural water resources. With many competing processes during the reactive transport of chemical species, it is not clear what processes are domina...

Brittleness and other properties such as low thermal stability, medium gas barrier properties and low solvent resistance (e.g., against water) of the pure biopolymer film are often insufficient for food packaging applications. The nanoscale distribution of nanoclays (such as montmorillonite, saponite or hectorite), with a high aspect ratio (100-1,500) and extremely high surface-to-volume ratio ...

A FORTRAN code for liquid water flow in unsaturated soil under the isothermal condition was developed to simulate water infiltration into Yolo light clay. The governing equation, that is, Richards' equation, was approximated by the finite-difference method. A normalized sensitivity coefficient was used in the sensitivity analysis of Richards' equation. Normalized sensitivity coefficient was cal...

An incubation experiment lasting 111 d was carried out to study the effect of the addition of three clay minerals (Nabentonite, Ca-bentonite, and zeolite) to soil derived from sewage sludge on water-extractable and exchangeable forms of four heavy metals (Zn, Cd, Cu, and Ni), as well as on soil organic matter mineralization, microbial biomass C and the release of inorganic N. The addition of cl...

Reflectance spectroscopy is a rapid and non-destructive method that can be used to detect organic compounds in geologic samples over a wide range of spatial scales that includes outcrops, hand samples, drill cores, and planetary surfaces. In order to assess the viability of this technique for quantification of organics and aliphatic compounds in particular, the present study examines how clay m...

pulse irrigation is consisted of an irrigation phase and a resting or non-operative irrigation phase. water intermittent use causes that advance front with less volume water over continuous irrigation is completed, which it effect on the pattern of soil moisture. another important subject in trickle irrigation is water distribution in non- operative irrigation that called redistribution. amount...