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Full-Text Articles in Physical Sciences and Mathematics
Water Hammer Dissipation In Pneumatic Slug Tests, David Ostendorf, Don J. Degroot, Philip J. Dunaj
Water Hammer Dissipation In Pneumatic Slug Tests, David Ostendorf, Don J. Degroot, Philip J. Dunaj
David Ostendorf
We model and measure the dissipation of water hammer induced by well casing and water elasticity with rapid valve opening at the start of a pneumatic slug test. The higher-frequency water hammer can obscure slower, aquifer-controlled, underdamped oscillations of the rigid water column, so a quantitative description of the elastic motion improves the ability of a slug test to calibrate the aquifer permeability k. Internal friction attenuates the water hammer, subject to a known headspace pressure at the air/water interface and equilibrium pressure at the top of the well screen. An analytical elastic solution is presented and matched to an …
Soil Gas Transport Above A Jet Fuel/Solvent Spill At Plattsburgh Air Force Base, David Ostendorf, Alan J. Lutenegger, Shawn P. Kelley, Erich S. Hinlein
Soil Gas Transport Above A Jet Fuel/Solvent Spill At Plattsburgh Air Force Base, David Ostendorf, Alan J. Lutenegger, Shawn P. Kelley, Erich S. Hinlein
David Ostendorf
We calibrate a stoichiometrically coupled soil gas diffusion model with spatially resolved observations of oxygen, carbon dioxide, total hydrocarbon, and trichloroethylene vapor concentrations in the unsaturated zone above a weathered jet fuel/solvent spill at Plattsburgh Air Force Base in upstate New York. The calibration suggests that aerobic microorganisms in the capillary fringe degrade jet fuel vapor at a steady rate of 9.5 μg hydrocarbons (m−2 s−1). The solvent does not degrade in the fringe, however, and the model and data estimate a steady evaporation rate of 1.2×10−2 μg TCE (m−2 s−1). Barometric pumping slightly alters the steady concentration profile at …
A Model For Stripping Multicomponent Vapor From Unsaturated Soil With Free And Trapped Residual Nonaqueous Phase Liquid, David Ostendorf, Chiu-On Ng, Chiang C. Mei
A Model For Stripping Multicomponent Vapor From Unsaturated Soil With Free And Trapped Residual Nonaqueous Phase Liquid, David Ostendorf, Chiu-On Ng, Chiang C. Mei
David Ostendorf
We present a model for the multicomponent vapor transport due to air venting in an unsaturated zone in the presence of free and trapped phases of residual nonaqueous phase liquid (NAPL). On the microscale the soil particles are assumed to form spherical aggregates with micropores filled with immobile water, trapped phases of NAPL and air. The interaggregate space is occupied with mobile air, and a thin film of free NAPL adheres on the aggregate surface. While the free NAPL can readily be in equilibrium with macropore vapor, the mass transfer from immobile phases in aggregates is rate-limited by aqueous diffusion. …