Physical Sciences and Mathematics Commons^™

Three-Dimensional Vapor Intrusion Modeling Approach That Combines Wind And Stack Effects On Indoor, Atmospheric, And Subsurface Domains, Elham Shirazi, Kelly G. Pennell

Civil Engineering Faculty Publications

Vapor intrusion (IV) exposure risks are difficult to characterize due to the role of atmospheric, building and subsurface processes. This study presents a three-dimensional VI model that extends the common subsurface fate and transport equations to incorporate wind and stack effects on indoor air pressure, building air exchange rate (AER) and indoor contaminant concentration to improve VI exposure risk estimates. The model incorporates three modeling programs: (1) COMSOL Multiphysics to model subsurface fate and transport processes, (2) CFD0 to model atmospheric air flow around the building, and (3) CONTAM to model indoor air quality. The combined VI model predicts AER …

Method Development For Detecting And Characterizing Manufactured Silver Nanoparticles In Soil Pore Water Using Asymmetrical Flow Field-Flow Fractionation, Annie R. Whitley

Theses and Dissertations--Plant and Soil Sciences

Recent advances in nanotechnology have led to the production of materials with nanoscale dimensions (nm) and properties distinctly different from their bulk (>100 nm) counterparts. With increased use, it is inevitable that nanomaterials will accumulate in the environment and there is concern that the novel properties of nanomaterials could result in detrimental environmental and human health effects. In particular, there has been concern recently regarding the use of silver (Ag) based nanomaterials as antimicrobial agents in consumer and medical products. Current regulations dealing with the discharge of metals into the environment are based on total concentrations with no consideration …

Capillary-Diffusion And Self-Diffusion Of Liquid Water In Unsaturated Soils, Ronald E. Phillips, V. L. Quisenberry Jr.

KWRRI Research Reports

Capillary-diffusion coefficients were measured by use of inflow and outflow methods. With both methods the capillary-diffusion coefficients decreased very rapidly with decreasing water content. The lighter textured soils were found to have the higher diffusion coefficients over the entire moisture content range studied, 0 to 1 bar tension.

Self-diffusion coefficients were measured over a moisture content range from air dryness to saturation using ³H as a tracer of water. Each of the soils gave the same diffusion characteristics when the self-diffusion coefficients were expressed as a function of either water content or average number of water layers on the …