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 31 for “"river sediment"”.
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River Sediment Sampling and Environment Quality Standards: A Case Study of the Ravensbourne River
Sediment is a major sink for heavy metals in river, and poses significant risks not only to river quality but also to aquatic and benthic organisms. At present in the UK, there are no mandatory sediment quality standards. This is partly due to insufficient toxicity data but also due to problems …
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Fluvial Depositional Processes of a Tropical River, Colombia, South America
… localized uplift downstream of the mouth of the river, sediment sources that produce both coarse-and-fine-grained load, and numerous over-bank flows caused by torrential rainfall.</p>
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Lacustrine Sediment Record of Multiple Quaternary Lava Dams on the Owyhee River, Southeastern Oregon
… impacted the Quaternary evolution of the Owyhee River. Sediment records from lava-dammed lakes were investigated to understand effects of the West Crater (WC) lava dam (~70 ka), the Saddle Butte 2 lava dam (~144 ka), and the Bogus Rim lava dam (~1.9 Ma). Evidence from the WC lava dam and related …
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Fine-grained sedimentation on the Chenier Plain Coast and inner continental shelf, northern Gulf of Mexico
… the evolution of a mud-dominated coastal sedimentary system on multiple time scales. Fine-grained systems exhibit different properties and behavior from sandy coasts, and have received relatively little research attention to date. Evidence is presented for shoreline accretion under …
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Fine-grained sedimentation on the Chenier Plain Coast and inner continental shelf, northern Gulf of Mexico
… the evolution of a mud-dominated coastal sedimentary system on multiple time scales. Fine-grained systems exhibit different properties and behavior from sandy coasts, and have received relatively little research attention to date. Evidence is presented for shoreline accretion under …
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Isolation and Identification of Biphenyl and Polychlorinated Biphenyl Degrading Microbes
The San Jacinto River system south of the I-10 overpass is heavily contaminated with biphenyl and polychlorinated biphenyls (PCBs), carcinogenic aromatic hydrocarbons that have a deleterious impact on the environment. While typically recalcitrant to most forms of environmental degradation, biphenyl …
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Applications of modifiers in supercritical fluid extraction and chromatography
… the extraction of polychlorinated biphenyls from river sediment and the extraction of the active components from a drug formulation. The separation of some compounds of pharmaceutical interest was also explored, where the addition of modifier, and in some cases an additive, was required to elute …
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Exploring fine sediment dynamics and the uncertainties associated with sediment fingerprinting in the Nene river basin, UK
… and ecological status of freshwater bodies. Fine sediment has been shown to be a major cause of the degradation of lakes and rivers, and as a result research in geomorphology has been directed towards the understanding of fine sediment dynamics. It was identified by a review of published …
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Supercritical fluid extraction applied to environmental pollutants from Chesapeake Bay sediment
… were extracted from dry Chesapeake bay marine sediment using two-step experimental conditions where step 1 was designed to extract the more volatile P AHs and used 100% CO2 and step 2 incorporated parameters for the removal and trapping of the less volatile P AHs with 10% acetone modified …
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Identification and analysis of extractable organic compounds present in pulp and paper mill effluent
… degradation in the aerated treatment system. The sediments of the aerated ponds were found to include a series of polychlorinated compounds ranging from C₂ to C₆ units. Many of these compounds, which may be degradation products of chlorinated lignin, were tentatively identified from their mass …
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Numerical Modeling of River Diversions in the Lower Mississippi River
… of man-made levees along the Lower Mississippi River (MR) has significantly reduced the River sediment input to the wetlands and much of the River's sediment is now lost to the Gulf of Mexico. The sediment load in the River has also been decreased by dams and river revetments along the Upper MR. …
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Effects of Capping on Biodegradation of Organic Contaminants in Sediments
Sediment capping remains an effective remediation technique for contaminated sediments due to its capability to contain contaminants and provide a sound habitat for indigenous biota. This research investigated the effect of capping on biodegradation of organic contaminants in Anacostia River …
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Toxicity of chlorpyrifos adsorbed on clay and humic acid to larval walleye
… have not been isolated, suspended solids, sediment, and pesticides are believed to be major factors. The objectives of this dissertation were to: (1) evaluate sources of variability in measuring cholinesterase activity, (2) determine the most sensitive life stage of walleye exposed to …
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Characterising the Namaqualand Mudbelt: Chronology, Palynology and Palaeoenvironments
… Bulk organic radiocarbon dating of the surface sediment had previously yielded older than expected ages. New 210Pb analysis has established that these surface sediments are modem and radiocarbon ages are now recalibrated to yield an adjusted age of ±3 470 cal yr BP at the base of the more …
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Seismic imaging and thermal modeling of active continental rifting processes in the Salton Trough, Southern California
… creates a deep accommodation space for sediment. When a major river flows into a late-stage rift, thick deltaic sediment can change the thermal regime and alter the mechanisms of extension and continental breakup. The Salton Trough, the northernmost rift segment of the Gulf of California …
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Chemical speciation and spatial distribution of heavy metals and their adsorption onto sediments of the Berg River, Western Cape, South Africa
The Berg River, Western Cape, South Africa, is an example of a catchment region where human pressures and conservation of natural resources collide. The river receives effluents from two large settlements and several smaller adjacent villages, including that of industrial and extensive agricultural …
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Glacial stratigraphy of northwestern Cass County, North Dakota
… and correlate the Late Wisconsinan glacial sediments of northwestern Cass County, North Dakota and to interpret the glacial history of the area.</p> <p>The surficial geology of the area was interpreted as: 1) collapsed glacial sediment, 2) glacial sediment draped over pre-existing …
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Nanotechnology and Biotechnology for Water Treatment: A Comparative Study
… obtained from the metal-contaminated Tietê River sediment in São Paulo, Brazil. This investigation focused on heavy metal removal since several prior studies have demonstrated the application of microorganisms in filtration systems for pathogen removal from water, but little is known about …
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Satellite Remote Sensing of Suspended Sediment Concentrations in Turbid Rivers
Suspended sediment concentration (SSC) is a critical parameter in the study of river sediment transport and water quality variation, but traditional measurements of SSC through in-situ sampling in rivers are expensive and time-consuming to perform. Thus, these methods cannot provide continuous SSC …
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Muskrat populations in Virginia's Elizabeth River: influence of environmental contaminants
… the contaminated lower region of the Elizabeth River was studied through an analysis of contaminant burdens, physiological characteristics, and population dynamics in comparison to those of muskrat populations from a less contaminated region of the Elizabeth River (upper region) and a nearby …
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