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 20 for “"tracer tests"”.
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On Single Well Forced Gradient Tracer Tests: Implications of Aquifer Physical Heterogeneity and Tracer Behaviour
Single well forced gradient tracer tests are a potential cost-effective approach to estimate in situ aquifer contaminant fate and transport parameters for use in natural attenuation assessments and remediation schemes. To date dipole flow tracer tests have been used to measure the conservative and …
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Development of hydrogel tracer beads and comparative tracer tests to better understand contaminant fate and transport in karst systems
… of NAPLs in karst aquifers is poorly understood. Tracer tests allow for qualitative characterization of hydraulic flow in the surface and subsurface, but their results may not be applicable to the movement of NAPL for which density plays a critical role. Particulate tracers have been used to …
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Electron donor contributions to denitrification in the Elk Valley Aquifer, North Dakota
Six denitrification tracer tests were performed over eight and a half years in in situ mesocosms (ISMs) in the Elk Valley Aquifer (EVA) in east-central North Dakota. Groundwater samples were analyzed to determine how much nitrate was lost beyond that explained by dilution of the bromide tracer. …
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Groundwater-surface water exchange within montane and alpine regions of the Front Range and Rocky Mountains, Colorado
… over 15 years, while multiple stream tracer tests were performed in the Gordon Gulch catchment in the Boulder Creek Critical Zone Observatory. These tracer tests were paired with time-lapse electrical resistivity and modeled using OTIS to examine how solute transport and storage …
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Application of a magnetic cyclone on a magnetite dense medium separation process
… of coarse-to-fine magnetite was established and tracer tests were done. From the tracer tests, it was evident that the efficiency of the dense medium cyclone could be improved when the SpecSepTM solenoids were applied, and also the cut-point could be lowered. It was finally determined that there …
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Design and evaluation of a modified in situ mesocosm to study denitrification in the Karlsruhe aquifer
… aquifer, near Minot, ND, in late June, 2003. Tracer tests were initiated in both ISMs to monitor denitrification rates at the two sites. The analytical results of water samples collected from the two ISMs showed no evidence of denitrification in the 0-ISM. However, the analytical results …
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Simulating water tracer test in naturally fractured reservoirs using discrete fracture and dual porosity models
… model. Another feature of this thesis is tracer testing. In this process, a chemical or radioactive element is injected to the reservoirs, and then it can be traced using the devices, which are designed to detect the tracers. Tracer tests have several advantages such as determining …
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Assessment of scaling and information requirements of the classical advection dispersion equation and a temporal-nonlocal advection dispersion equation at the MADE site, An
… Site in Columbus, MS, is a research site where tracer tests have been performed to further understand transport processes in heterogeneous material. Tracer tests have exhibited anomalous plume behavior, including early arrival times and heavy, power-law late-time tails that the classical …
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The hydrogeochemistry of pond and rice field recharge : implications for the arsenic contaminated aquifers in Bangladesh
… monitor soil moisture and water potential, tracer tests to visualize flow patterns, soil cores to determine soil properties, and soil and water samples to ascertain chemical characteristics. The large amount of generated data were synthesized with hydrologic, geochemical and mass-balance …
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A bubble-particle interaction model for flotation combining hydrodynamic and surface forces
… has been examined by conducting experimental tracer tests. These tests have been performed with two tracer materials to characterize mixing for both the liquid and the solids in a single system. The measured residence time distributions have shown that the assumption of equating liquid and …
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Investigations of rapid groundwater flow and karst in the Chalk
… dry valleys, in Zone 3 where the Chalk outcrops. Tracer tests from three stream sinks in Zone 1 demonstrated connections to springs and rapid groundwater flow (1-6 km.d-1) indicating connected networks of conduits and large fissures over distances up to 5.1 km. Rapid flow was accompanied by …
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Post-treatment horizontal hydraulic fracture modeling with integrated chemical tracer analysis, a case study
… resulted in the development of chemical tracer technologies. While the utilization of tracer technologies to track water during reservoir development is mature, the use of chemical tracers in unconventional hydraulic fracturing operations is relatively new. With the increasing use of …
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An Investigation of Groundwater Flow in the Vicinity of Patoka Dam, Indiana
… flow investigation using multiple fluorescent tracer tests, analysis of water-table elevations, isopach mapping of the Glen Dean Limestone, and spring hydrograph analysis was performed to better understand local groundwater hydrology in the vicinity of the existing water-control structures. …
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Carbon dosing of denitrifying bioreactors to remove nitrate from agricultural drainage
… day⁻¹ in 2021 (second year of dosing). Based on tracer tests of the mesocosm bioreactors, I investigated the effects of added carbon on the internal hydraulic performance of bioreactors. The results of the tracer tests revealed that carbon dosing had no significant effect on the hydraulic …
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Assessment and improvement of hydraulic disinfection efficiency of a live small drinking water system in South Africa
… in collaboration with Umgeni Water. Physical tracer tests were conducted on a 10,000L cylindrical tank acting as the contact chamber to assess the hydraulic disinfection efficiency in terms of baffling factor (BF), before and after the installation of a 4-way inlet manifold modification. This …
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Hydraulic evaluation of a denitrifying bioreactor with baffles
… 2016. A series of potassium bromide conservative tracer tests were performed on this new design during 2018 as well as at three conventionally designed bioreactors to evaluate how the baffles impacted bioreactor hydraulic functioning. This new bioreactor had greater effective volume, lower …
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Field Investigation of Stream-Aquifer Interactions: A Case Study in Coastal California
… push subsurface sampling, constant rate pumping tests, dye tracer tests, electrical resistivity interrogation of the subsurface, and long-term passive monitoring of aquifer hydraulic heads and stream stage, are reported. Additionally, results of laboratory falling-head permeameter tests and …
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Anomalous transport through porous and fractured media
… media, animal and human foraging patterns, tracer diffusion in biological systems, and transport in complex networks. Understanding the origin of anomalous transport is essential, because it determines the likelihood of high-impact, low-probability events and therefore exerts a dominant …
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Comparison of non-reactive solute transport models for the evaluation of fluid flow in leaching beds
… leaching studies and quantified using step tracer tests. This is based on the underlying principle that the movement of inert tracer molecules within an irrigated bed at steady state is identical to the solution flow path within the bed. The second objective was to test the ability of nine …
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A Conceptual Model of Groundwater Flow at the Midway, Utah Fish Hatchery as Constrained by Geochemical, Physical Hydrogeological, and Geophysical Methods
In addition to a loss of potential revenues from Utah's $393 million sport fishing industry, the state expends millions of dollars every year on costs associated with whirling disease mitigation and prevention. A state fish hatchery at Midway, Utah was closed when the shallow unconfined aquifer …