Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 792 for “"Contaminant"”.
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The Development of the Contaminant Exceedance Rating System (CERS) for Comparing Groundwater Contaminant Data
<p>The typical approach to mapping groundwater contaminant plumes involves drawing plume contours out to each contaminant’s site-specific cleanup criterion. Cleanup criteria differ between contaminants, sites and U.S. states. For this reason, it is difficult to determine which monitoring wells, …
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Organic Contaminant Release from Melting Snow
Snow efficiently scavenges organic contaminants from the atmosphere. Those chemicals can be released in short, concentrated pulses during spring snowmelt, potentially affecting both aquatic and terrestrial environments. In order to investigate the behavior of organic contaminants in melting snow …
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Evaluation of Contaminant Containment at Regina Landfill
… above or within the vadose zone to prevent contaminant migration into the groundwater system. Numerical estimates of design lives for assessment of barrier system performance are generally acceptable under numerous landfill regulations. Predictive models work under the general assumption …
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Tide-influenced contaminant transport in coastal aquifers
… which cause complicated groundwater flow and contaminant transport phenomena in regions immediately adjacent to the coast. This study is designed to address the significance of tidal influence on contaminant transport by focusing on one-dimensional homogeneous coastal aquifers. This study …
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Improved predictions of contaminant transport in rivers
<p>To improve predictions of contaminant transport in rivers, two analytical models and one empirical model were evaluated. Analytical solutions of the model of Reichert and Wanner (1991), which represents mixing in the advective zone by dividing the channel into a flowing zone and a stagnant zone, …
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Inorganic contaminant transport through unsaturated clay soil
The fate of contaminant migration through the subsurface environment as well as their potential hazard to humans, animals, and aquatic life has become one of the major current concerns of the scientific community. Accordingly, various theoretical and experimental studies have been conducted on the …
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Stochastic modelling of contaminant transport in porous media
The stochastic model of solute transport describes the motion of fluid elements in a porous medium as stochastic variation of the fluid velocity, produced by pore wall impacts. This gives a stochastic differential equation for fluid displacements, and solute transport is obtained as the cumulative …
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Protocol for characterizing contaminant emissions during construction activities
… of particulate, gaseous and microbiological contaminants that were produced. The activities were: prepared dry wall sanding, metal cutting, water-damaged drywall removal, ceiling tile removal, carpet removal/installation, painting, air duct caulking/sealing. Sampling was performed near each …
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Development of an analytical groundwater contaminant transport model
… Domestic wastewater contains a variety of contaminants that may result in degradation of water resources if the OWS is improperly designed, installed or operated. There is a large diversity in the contaminants composing the wastewater stream from household though nutrients (nitrogen, …
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Modeling contaminant exposure in a single-family house
… this study, occupational exposure to household contaminants in a single-family house with several ventilation, heating, and climactic conditions was simulated using CFD. Typical household exposure to CO2, CO, HCHO (formaldehyde), NO2, and water vapor is evaluated over the day for a generic …
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Evaluation of Contaminant Removal Through Soil Aquifer Treatment by a Lab Scale Soil Column Experiment Including a Trace Contaminant Spike Test
Soil aquifer treatment (SAT), the removal of contaminants during percolation through soil, is a strategy employed in managed aquifer recharge (MAR), one method of indirect potable water reuse. As part of Hampton Roads Sanitation District's (HRSD) MAR project, The Sustainable Water Initiative for …
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Modeling person-to-person contaminant transport in enclosed environments
<p>It is essential to predict person-to-person contaminant transport in enclosed environments to improve air distribution design and reduce the infection risk from airborne infectious diseases. This study aims to improve and accelerate the simulation of person-to-person contaminant transport in …
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Understanding The Factors Influencing Contaminant Attenuation And Plume Persistence
… of historical groundwater-withdrawal and contaminant-concentration data collected from long-term pump-and-treat operations. The potential factors contributing to plume persistence are generally recognized to include incomplete isolation of the source zone, permeability heterogeneity, …
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Modeling contaminant spread and mitigation in the indoor environment
… across the building envelope to prevent exterior contaminant infiltration; and 2) some contaminated indoor zones can be “isolated” from adjacent ones by adjusting the relative pressure differences. Realistic particle distributions typical to a particular contamination threat of interest are …
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Soil-Bentonite Cutoff Walls: Hydraulic Conductivity and Contaminant Transport
… cutoff walls are commonly used to contain contaminants in the subsurface. A key property in determining the effectiveness of a cutoff wall is its hydraulic conductivity. There are important difficulties and uncertainties regarding the accuracy of commonly used methods of measuring the …
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Agricultural Contaminant Source and Transport in a Karst Groundwater Basin
… and subsurface flow in karst aquifers allow for contaminants to move quickly into and through a groundwater basin. When groundwater returns to the surface via a spring or springs, any contaminants within the water become part of surface streams and rivers. These in turn, impact water quality in …
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Modeling contaminant transport and fate and subsequent impacts on ecosystems
… System (GMS) to accurately simulate metal contaminant mobility where oxides are present. In the model development, the parabolic concentration layer approximation and the operator split technique were used to solve the microscopic diffusion equation coupled with macroscopic advection and …
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Novel anitbody-based assays for disease and food contaminant detection
… and for the detection of the food contaminants, aflatoxin BI (AFBl), and the p-lactam antibiotic, ampicillin. Imrnunoassays based on the detection of antibodies to a phospholipase D (PLD) exotoxin of Corynebacterium pseudotuberculosis, the causative agent of caseous lymphadenitis …
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