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 162 for “"Aquatic Systems"”.
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Ecological Limitations and Potentials of Artificial Aquatic Systems
… of the Earth, a multitude of artificial aquatic systems have appeared, both deliberately and accidentally. Human modifications to the hydroscape range from alteration of existing waterbodies to construction of new ones. The extent and ecosystem services of these systems are underexplored, …
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Patterns of microbial community development in isolated aquatic systems
… of microbial community development in isolated aquatic systems to the MacArthur-Wilson equilibrium theory of island biogeography and suggest alternative models for the observed patterns. Water-filled plastic containers were used as aquatic islands to investigate the colonization dynamics of …
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Environmental impact of heavy metal pollution in natural aquatic systems
… provide the appropriate level of protection for aquatic life and other uses of the resource, it is important to be able to predict the environmental distribution of important metals on spatial and temporal scales and to do so with particular emphasis on the water column concentrations. Regulatory …
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Towards an understanding of synthetic glucocorticoid hazards in aquatic systems.
… with apical outcomes following exposure in aquatic matrices. First, I performed a critical review of existing literature to characterize the global occurrence of synthetic glucocorticoids in freshwater matrices detected by either analytical chemistry methods or bioanalytical surveillance …
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Monitoring and regulating cyanobacterial metabolites (microcystins and geosmin) in aquatic systems.
Cyanobacterial secondary metabolites can cause serious harm to animals and humans (cyanotoxins) and can have a major financial impact on the potable water and aquaculture industries (taste and odour compounds). Understanding the factors that affect cyanotoxin production can help in exploring means …
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An assessment of reverse electrodialysis for application to small-scale aquatic systems
… RED to other environmental energy harvesting systems and determines RED to be a competitive power source within the environmental constraints of the Artic. Regarding the use of RED as a secondary power source to charge lithium ion batteries, it is found that it would require an RED stack over …
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Influence of natural organic matter on the mobility of arsenic in aquatic systems, soils and sediments
The element As is today recognized as one of the most dangerous inorganic contaminants and threats for the world’s water resources. Arsenic is ubiquitious in the earth crust and humans are especially affected through As polluted drinking water supplies. The occurrence of high As groundwater …
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Predicting thermodynamic and transport parameters for metal contaminant sorption to hydrated metal oxides in aquatic systems
Hydrated oxides such as HAO,'HFO, goethite, and BA40 are prevalent in soils and sediments as discrete particles or as coatings. These microporous oxides have large surface areas and high affmity for metal ions, and hence they act as both a sink and a source for anthropogenically released metal …
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Effects of Water Column P-availability and Litter Microbial Mediated Processes and Stoichiometry in Aquatic Systems
<p>Anthropogenic nutrient enrichment of aquatic ecosystems is prevalent and can have detrimental effects on biological condition. Many of these effects have been attributed directly or indirectly to changes in autotrophic processes. However, in detrital-based streams changes in course detrital …
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Photochemical processes in engineered aquatic systems for remediation of per- and polyfluoroalkyl substances and algae cultivation
… produced reactive species in algal cultivation systems where cells excrete light-absorbing extracellular substances. The production of highly reductive hydrated electrons (eaq−; NHE = −2.9 V) in UV-sulfite treatment has shown promise in the destruction of PFASs. PFASs are a component in aqueous …
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Hydrogen peroxide mediated oxidation of ferrous iron and associated production of hydroxyl radicals in natural aquatic systems
… kinetics of ferrous iron, Fe(II), in natural aquatic systems is of interest due to both its importance to the biogeochemistry of iron, a critical micronutrient, and also due to the formation of reactive oxygen species (ROS) during these oxidation reactions. The most important oxidants of …
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Observations of a particle capture on a cylindrical collector : implications for particle accumulation and removal in aquatic systems
… collectors is an important mechanism in many aquatic processes, such as larval settlement, suspension feeding, and vegetative filtration. The collector Reynolds number (Rec), based on the collector diameter, typically ranges from 1-1000 in aquatic environments. No analytical solutions exist to …
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Effect of polysulfides on cinnabar solubility, partitioning, and methylation by Desulfovibrio desufuricans
… be the most important methylators of mercury in aquatic systems. Methylation may be controlled by the availability of mercury to these bacteria and therefore may depend on mercury speciation in sulfidic water ...
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Relationships between water quality, species composition, biodiversity and ecosystem function in lakes and flooded pits exposed to uranium mining activities in Northern Saskatechewan
… mining activities have the potential to impact aquatic systems through mine drainage (runoff) and the release of treated effluent into nearby watersheds. Such anthropogenic exposure can lead to elevated concentrations of metals and major ions, which may impact aquatic biota. Previous studies …
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Fate of metals in presence of minerals and mineral-organic assemblages
<p>Metals can enter aquatic systems from natural and anthropogenic processes associated with weathering, sediment re-suspension, industrial activities, and atmospheric deposition. Metals pose health and environmental risks at high concentrations due to their potential toxicity and bioaccumulation, …
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An Isotopic Examination of Cave, Spring and Epigean Trophic Structures in Mammoth Cave National Park
… trophic interactions between cave and epigean aquatic systems or their connectivity via natural springs. The purpose of this study was to use stable isotopes of C and N to describe and compare the trophic structure of epigean, spring and cave aquatic systems within Mammoth Cave National Park. …
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A comparison of techniques for estimating the hazard of chemicals in the aquatic environment
… of cadmium constituting a threat to aquatic ecosystems were derived from laboratory tests conducted at two levels of the biological hierarchy. A population level estimate was derived from single species toxicity tests and a community level estimate was derived from laboratory tests on …
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Geospatial Modeling of Forest Road Networks and Their Effect on Stream Macroinvertebrate Communities
… largest contributors of sediment pollution to aquatic systems. Though impacts of road networks on aquatic systems can be potentially severe, little work has been performed to evaluate the effect that road spatial location within a watershed has on water quality. To address this issue from a …
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Environmental dynamics of Benomyl and Thiabendazole
… fate and distribution in the terrestrial and aquatic phases of a laboratory microcosm comprised of silty clay loam soil and plants. The soil component constituted a major relocation site, with approximately 45 and 75% of initial Benomyl (recovered as MBC) and Thiabendazole concentrations being …
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Comparative Bioavailability of Dietary and Dissolved Cadmium to Freshwater Aquatic Snails
Heavy metal bioaccumulation in aquatic organisms may occur through direct or indirect uptake routes. Research indicates that the significance of uptake route varies with contaminant and organism exposed. The relative importance of different metal sources in aquatic systems was investigated by …
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