Laurence H Smith

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The rates of methane utilization and trichloroethylene (TCE) cometabolism by a methanotrophic mixed culture were characterized in batch and pseudo-steady-state studies. Procedures for determination of the rate coefficients and their uncertainties by fitting a numerical model to experimental data are described. The model consisted of a system of differential(More)
The objective of this research was to evaluate several factors affecting the performance of a two-stage treatment system employing methane-oxidizing bacteria for trichloroethylene (TCE) biodegradation. The system consists of a completely mixed growth reactor and a plug-flow transformation reactor in which the TCE is cometabolized. Laboratory studies were(More)
Two technologies in combination, cometabolic bioremediation and in-well vapor stripping, were applied to reduce trichloroethylene (TCE) concentrations in groundwater at a contaminant source area without the need to pump contaminated groundwater to the surface for treatment. The vapor-stripping well reduced source TCE concentrations (as high as 6-9 mg/L) by(More)
Studies of rates of Sr transport from nutrient solutions containing 8 concentrations of Sr indicate a definite trend towards higher rates of Sr transport by roots of intact 12-day-old Regal barley (Hordeum vulgare, L.) seedlings as compared with Tregal. Differences in rates of Sr transport between the 2 varieties were also indicated by higher concentrations(More)
A normobaric hypoxia chamber was designed in which large numbers of mice (up to 250) were made polycythemic, after which they were used in an erythropoietin assay. The hypoxic atmosphere was composed of air diluted with N2 gas generated from liquid N2. Continuous exposure of mice to 8% O2 for 11 da resulted in a polycythemia of sufficient magnitude and(More)
The fluorescence associated with benzo[a]pyrene [BP] moieties covalently attached to the nucleic acid (DNA plus RNA) isolated from the epidermis of BP-treated mice was examined at 77 K in frozen aqueous solutions by use of a photon-counting fluorimeter operating in the synchronous scanning mode. The excitation and emission wavelengths were scanned(More)
An in vitro method for studying the interaction between tritiated benzo[a]pyrene ([3H]BP) and intact mouse skin was investigated. [3H]BP was applied to the epidermal surface of the skin floating on medium, and radioactivity in the medium was measured periodically. After 48-h incubation, about 45% of the radioactivity was in the medium; of this amount, about(More)
In a series of three separate experiments mice were exposed to various concentrations of fossil liquids obtained from coal, oil shale or natural petroleum. All materials were capable of inducing squamous cell carcinoma, but potency differed substantially. Skin carcinogenicity was markedly greater for both coal or oil shale liquids than for natural(More)
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