Rodrick D. Lentz* USDA-ARS Northwest Irrigation and Soils Research Lab. 3793 N 3600 E Kimberly, ID 83341 High water infiltration rates in unlined canals, reservoirs, and the inflow end of furrows relative to outflow ends result in excessive seepage losses and reduced furrow irrigation application uniformity. This study evaluated the use of cross-linked, anionic, polyacrylamide hydrogel (XPAM), ...

The flux of several polycyclic aromatic hydrocarbons (PAHs) from coal tar-impacted river sediment was measured under various seepage rates in a laboratory scale. The batch PAH equilibrium data between aqueous phase (C(eq)) and sediment phase was well-explained using a Raoult's law approach. In the flux measurement from column study, the steady-state PAH concentrations (C(infinity)) in the efflu...

The effects of seepage on streambank erosion and failure are less understood compared to fluvial processes, especially the linkage between surface water and groundwater mechanisms. Field data are needed to validate laboratory seepage erosion and instability conclusions and to understand how engineering tools and methods may be applied to field conditions. An innovative trench injection system w...

We measured groundwater apparent age (s) and seepage rate (v) in a sandy streambed using point-scale sampling and seepage blankets (a novel seepage meter). We found very similar MTT estimates from streambed point sampling in a 58 m reach (29 years) and a 2.5 km reach (31 years). The TTD for groundwater discharging to the stream was best fit by a gamma distribution model and was very similar for...

Despite improved endotracheal tube designs, aspiration remains a cause of pulmonary complications. This in vitro study evaluates the efficacy of positive end-expiratory pressure (PEEP) in reducing the incidence of seepage around endotracheal tubes during mechanical (MV) and spontaneous ventilation (SV). Two transparent plastic "tracheas" with cuffed and uncuffed endotracheal tubes simulated adu...

We examine a dynamic model for the disruption of information flow in hierarchical social networks by considering the vertex-pursuit game Seepage played in directed acyclic graphs (DAGs). In Seepage, agents attempt to block the movement of an intruder who moves downward from the source node to a sink. We propose a generalized stochastic model for DAGs with given expected total degree sequence. S...

A novel discrete singular convolution (DSC)  formulation  is  presented for the seepage analysis in irregular geometric porous media. The DSC is a new promising numerical approach which has been recently applied to solve several engineering problems. For a medium with regular geometry, realizing of the DSC for the seepage analysis is straight forward. But DSC implementation for a medium with ir...