A pilot scale demonstration of a biological permeable barrier was conducted in a pentachlorophenol-contaminated aquifer at a wood preserving facility. A permeable reactor was constructed to fit within a
large diameter well. Arranged in series, a cylindrical reactor 24" x 36" (0.61 x 0.91m) (diameter x height)
was partitioned to...
Three-dimensional finite element models are developed to simulate the behavior of four fill-scale reinforced concrete beams. The beams are constructed with different fiber-reinforced polymer (FRP) strengthening schemes, and are modeled using ANSYS, a commercially available finite element analysis program. The experimental beams replicate the transverse beams of the Horsetail Creek...
The Horsetail Creek Bridge (HCB), constructed in 1914, is located along the Historic Columbia River Highway in Oregon. The original cross beams from the HCB were substantially deficient in shear strength, particularly for the projected increase in traffic loads. One control beam and three beams with varying configurations of a...
This microcosm study demonstrated the enhanced anaerobic transformation of vinyl chloride (VC) to ethylene. A previous microcosm study from Point Mugu site showed the accumulation of VC due to the slow transformation step of VC to ethylene. To overcome the rate-limiting step, two laboratory experiments tested the effect of trichloroethylene...
The addition of exogenously supplied hydrogen stimulates PCP reductive
dechlorination and increases bacterial growth. While research focuses mainly on
pure cultures, few exist capable of aryl reductive dechlorination, and few markers
exist to identify reductively dechlorinating bacteria within mixed cultures.
Furthermore, most active bioremediation projects stimulate mixed cultures of native...
A method is described for determining the partition coefficient, K, for radon gas
distributed between an aqueous phase and an organic solvent. The method uses
sequential extractions of radon into equal volume aliquots of organic solvent. The
radon-laden organic liquid is then counted on a liquid scintillation analyzer with alpha-beta...
The nonlinear response of an ocean system subjected to random excitations can exhibit very complex dynamic behaviors including jump phenomena and coexistence of attractors. In this study, the stochastic system response behavior of a simple (Duffing) oscillator under narrow-band random excitations is first examined in the subharmonic resonance region. A...