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 59 for “"Polychlorinated biphenyls (PCBs)"”.
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The effect of protozoan grazers on the cycling of polychlorinated biphenyls (PCBs) in marine systems
… the speciation of organic contaminants such as polychlorinated biphenyls (PCBs) and ultimately determine their residence time in a particular environment. In marine systems, the microbial loop influences organic carbon dynamics by recycling a significant fraction of dissolved and particulate …
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The effect of protozoan grazers on the cycling of polychlorinated biphenyls (PCBs) in marine systems
… the speciation of organic contaminants such as polychlorinated biphenyls (PCBs) and ultimately determine their residence time in a particular environment. In marine systems, the microbial loop influences organic carbon dynamics by recycling a significant fraction of dissolved and particulate …
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Investigations into the determination of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) by capillary gas chromatography
… of PAHs (16 priority PAHs as an example) and PCBs (10 PCB congeners, representing 10 isomeric groups) by capillary gas chromatography coupled with mass spectrometry (GC/MS, for PAHs) and electron capture detection (GC/ECD , for PCBs) were studied, with emphasis on the effect of solvent. Having …
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Using polyethylene passive sampling to assess transport of polychlorinated biphenyls (PCBs) between contaminated sediments, water, and biota
Polychlorinated biphenyls (PCBs), which were a widely used group of chemicals before their manufacture was banned in 1979 in the United States, still contaminate numerous aquatic systems. Although there are ongoing efforts to remediate these sites, our ability to implement effective remediation …
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Effects of polychlorinated biphenyls (PCBs) on hepatic enzyme induction, uterotropic responses, and thyroid hormone levels in prepubertal female rats
… rats, was developed to study effects of polychlorinated biphenyls (PCBs) on hepatic enzyme induction, uterotropic responses, and thyroid hormone levels. Three approaches have been used to study the multiple effects of PCB mixtures: (1) environmental mixtures (soil, dust and air samples) …
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Bioremediation of polychlorinated biphenyls (PCBs) on contaminated soils : a case study of Rietvlei Farm Borehole No. 11, Limpopo Province, South Africa
Polychlorinated biphenyls (PCBs) are worldwide environmental pollutants which contaminate the environment through careless disposal practices and accidental spills or leakages from electrical transformers. These organic compounds are lipophilic chemicals soluble in fats, slightly soluble in water …
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Morphometric changes in the prepubertal rat thyroid gland following acute exposure to PCBs
… bioassay, developed to study the effects of polychlorinated biphenyls (PCBs), were further used to examine the effects of PCBs on thyroid glands through examination of serum thyroxine (T$\sb4$) and morphometry.
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Comparative fates of three structurally distinct PCB congeners in rats and house flies
… biotransformation and biological activities of polychlorinated biphenyls (PCBs) are influenced by the number and position of chlorine atoms on the biphenyl rings. The excretion and tissue retention of three $\sp{14}$C-labeled structurally distinct lower chlorinated PCBs (2,2$\sp\prime$,5-tri-, …
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Neurobehavioral and neurochemical effects of ortho-substituted polychlorinated biphenyl congeners in perinatally exposed rats
Polychlorinated biphenyls (PCBs) are persistent contaminants in the environment. PCBs are lipophilic and from the environment bioaccumulate in living organisms. People are exposed to PCBs through the food chain. PCB exposure during development of the central nervous system (CNS) results in …
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Energetic costs of toxicant metabolism in rainbow trout ( Oncorhynchus mykiss)
… a variety of environmental toxicants including polychlorinated biphenyls (PCBs). A portion of the energy assimilated by the fish is dedicated to detoxification. This study investigates the changes in energetic demands associated with increased detoxification. Two CYP1A inducers were employed, …
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Are PCBS in phytoplankton and zooplankton at equilibrium with the water in which they live?
Food chain bioaccumulation of polychlorinated biphenyls (PCBs) can result in harmful concentrations within higher trophic level organisms such as fish and humans. It is important to consider how the concentrations of PCBs in phytoplankton and zooplankton affect higher trophic organisms. It was …
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Mass balance modeling of polychlorinated biphenyls in the Lower Duwamish Waterway
… in Seattle, Washington is contaminated with polychlorinated biphenyls (PCBs). A zero dimensional mass balance of the 5 mile long waterway, which ends in Elliott Bay, helps to determine the different sources and concentrations of PCBs within the Lower Duwamish Waterway to aid future remedial …
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Experimental and theoretical modeling of DNAPL transport in vertical fractured media
… (DNAPLs) such as chlorinated solvents and polychlorinated biphenyls (PCBs) has become an important environmental concern in many industrialized areas. Accidental spills, poor storage facilities and inadequate disposal practices are factors contributing to the release of these chemicals into …
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Approaches for assessing the presence and impact of thyroid hormone disrupting chemicals in Delphinid cetaceans
… for persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs). During periods of lipid mobilization such as lactation, PCBs from the blubber are mobilized into the circulatory system and may cause toxic effects. One particular toxic mechanism may include the induction of …
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A Survey of Superfund Chemicals in Massachusetts Farms
… polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and volatile organic compounds (VOCs)) in water, soil and produce samples from organic farms in Massachusetts, USA. Measured concentrations were compared to regional and federal …
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Supercritical fluid extraction of polychlorinated biphenyls and organochlorine pesticides from mussel tissue (Mytilus edulis)
… fluid extraction (SFE) of twenty one polychlorinated biphenyls (PCBs) and eight organochlorine pesticides (OCPs) from freeze dried mussel tissue is discussed, demonstrated, and compared to traditional Soxhlet extractions. The aim of this study was to determine the efficacy of SFE for …
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Investigation of Persistent Organic Pollutants in Breast Milk // Изследване на устойчиви органични замърсители в майчино мляко
… samples were collected and analysed for 29 POPs (polychlorinated biphenyls, PCBs and organochlorine pesticides, OCPs). A gas chromatographic method with mass detection was modified and validated for the simultaneous quantitative determination of PCBs and OCPs in breast milk samples. Residues of …
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PREDICTING CONTAMINANT TRANSFER FOLLOWING RE-ESTABLISHED CONNECTIVITY IN THE BOARDMAN RIVER
… anthropogenic contaminants such as mercury (Hg), polychlorinated biphenyls (PCBs), dichloro-diphenyl-trichloroethylene (DDT), and organochloride compounds. Migratory fish accumulate and magnify contaminants within their tissues and transport them across ecosystem boundaries. Re-established …
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Cytochrome P450 1A1 and aromatase (CYP19) in cetaceans : enzyme expression and relationship to contaminant exposure
… aromatic hydrocarbons, including certain polychlorinated biphenyls (PCBs), has been correlated with toxic effects in rodents. CYP1A1 expression was measured in multiple organs from beluga whales and white-sided dolphins and integument biopsies from bottlenose dolphins. Age and sex do not …
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