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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 71 for “"Surface sediments"”.
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An Assessment of Heavy Metal Concentrations in Surface Sediments from the Knysna Estuary
… grain size, and total organic carbon within 36 surface sediment samples from the Ashmead Channel in the Knysna Estuary. 15 surface sediment samples were also analysed from Chongming Island in the Yangtze Estuary of the People's Republic of China, and the results compared between the two systems, …
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Small-Scale Resuspension and Redistribution of Surface Sediments in the Northeast Gulf of Mexico
… the seafloor contained recently deposited marine sediments contaminated by the oil spill. The initial deposition of these contaminated marine sediments was likely not the end of the journey for the particles. Downslope gravitational processes and events of increased current speed in the deep ocean …
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Sulfate reduction and iron-manganese cycling in intertidal surface sediments of the southern North Sea
Zielsetzung der vorliegenden Dissertation ist die Erfassung der Dynamik der Mangan-, Eisen- und Schwefel-Kreisläufe in unterschiedlichen intertidalen Sedimenten. Saisonale biogeochemische Untersuchungen in Sand-, Misch-, und Schlickwatt-Sedimenten der Nordseeinsel Spiekeroog geben Aufschluss über …
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Analysis of Factors Controlling the Distribution of Trace Elements in Surface Sediments of Coastal Alabama
… on the distribution of trace elements in surface sediments of the study area. PCA indicates that the main controls on the dataset are total surface area of sediment particles, relative abundance of high CEC clays in sediment, and salinity of bottom water at sample locations.
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The distribution and depositional history of metals in surface sediments of the Aberjona River watershed
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1991.
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The marine geochemistry of biogenic and redox sensitive elements in the oxygen minimum zone of western continental margin of India surface sediments
Es wurden detaillierte anorganisch-geochemische Analysen an Oberflächensedimenten entlang des westlichen Kontinentalhanges von Indien (WCMI) durchgeführt, um den Einfluß der Sauerstoff-Minimum-Zone (OMZ) auf die Verteilung von Spurenmetallen zu verstehen. Die neuen Daten für organischen Kohlenstoff …
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ΓΕΩΧΗΜΕΙΑ ΠΑΡΑΚΤΙΩΝ ΙΖΗΜΑΤΩΝ (ΠΕΡΙΟΧΕΣ ΙΘΑΚΗΣ-ΚΕΦΑΛΛΗΝΙΑΣ-ΑΣΤΑΚΟΥ)
SURFACE SEDIMENTS FROM THREE SEMIENCLOSED EMBAYMENTS (ITHAKI, ARGOSTOLI AND ASTAKOS) WAS STUDIED FROM GEOCHEMISTRY, SEDIMENTOLOGY AND MINERALOGY VIEW. THE FOLLOWING CONCLUSIONS 1) THE MINERALS CONSIST MAINLY OF CALCITE; QUART, FELDSPAR, ILLITE AND CHLORITE 2) THREE DISTINCT TRANSPORT MECHANISMS …
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Composition and characteristics of particles in the ocean : evidence for present day resuspension
… matter in the water column and the underlying surface sediments verifies the occurrence of local, present-day resuspension in the deep sea. The location of the major portion of this work was the South Iceland Rise, a region influenced by the flow of Norwegian Sea Overflow Water. Measured …
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Chlorophyll diagenesis in the water column and sediments of the Black Sea
… of chlorophyll in the Black Sea water column and sediments. Measurements are made of total chlorophyll in sediment traps from two locations and depths in the water column, and at two locations in surface sediments. Individual chlorophyll degradation products are also identified. This data is used …
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Sedimentary lipids as indicators of depositional conditions in the coastal Peruvian upwelling regime
… and tetrahymanol) were quantified in Peru margin sediments from both the oxygen minimum zone (OMZ) and several near-shore locations. I discuss the utility of the lipid profiles, the alkenone-Uk37 "paleothermometer", the n-alkane CPI, and several stanol/stenol ratios as indicators of short-term …
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Chemical Survey of Selected South Dakota Lake Sediments
… and organic nitrogen were measured in bottom sediments of 16 lakes and ponds in northeast South Dakota. These lakes were glaciated, relatively shallow, and productive. Ranges of the surface sediments were: available phosphorus, 2 to 42 ppm; organic carbon, 0.94 to 5.34 percent; and organic …
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Biogeochemistry of dissolved free amino acids in marine sediments
… in interstitial water samples squeezed from sediments collected in a variety of depositional environments. These sediments were further characterized by measurements of total organic carbon, total nitrogen, dissolved organic carbon, total hydrolyzable amino acids, and pore water-dissolved …
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Transformations of carotenoids in the oceanic water column
… Suspended particulate matter collected from surface waters of Buzzards Bay, Massachusetts and the Peru upwelling system has a carotenoid distribution reflecting the phytoplanktonic source of the material. The carotenoid distribution of sediment trap samples collected in these same areas was …
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The Effects of Benthic Organisms on Intertidal Sediment Erodibility
… small-scale disturbance recovery. The erosion of surface sediments is also vital to benthic-pelagic coupling, where resuspended microbes and organic material become available to suspension feeders and/or transported to adjacent habitats. On sandflats, the organisms living within sediments have …
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Muskrat populations in Virginia's Elizabeth River: influence of environmental contaminants
… concentration of 14 PAH compounds detected in surface sediments from the lower region of the Elizabeth River (N = 10) was significantly greater than the mean concentration detected in surface sediments collected from the upper region of the Elizabeth River (N = 5) or Nansemond River (N = 5). Of …
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The marine geochemistry of thorium and protactinium
… in the deepest sediment trap sample and in surface sediments. However, 230Th/232Th and 231Pa/232Th ratios were 2.5 times higher in trapped particles than in surface sediments. The 230Th/232Th ratios were 5.5 times higher in particles filtered at 3600 m and 5000 m at Site E than in surface …
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Snail grazing effects on the composition and metabolism of benthic diatom communities and subsequent effects on fish growth
… but this effect could be inhibited by raking the sediments daily. At low densities Ilyanassa's acceleration of nutrient cycling stimulates algal growth, but this effect is overwhelmed at higher densities by overgrazing and stirring inhibition. The dominant benthic algal group in the containers …
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Ecology and physiology of bacterial activity in a temperate saltmarsh lagoon, with an emphasis on nitrogen fixation
… production and nitrogenase activity in marine sediments and water were examined in Langebaan Lagoon, a temperate saltmarsh ecosystem. Emphasis was placed on factors modulating rates and patterns of nitrogen fixation. Nitrogen fixation appeared to be dominated by heterotrophic bacteria. Rates of …
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Biogeochemical applications of compound-specific radiocarbon analysis
… Monica Basin (SMB) and Santa Barbara Basin (SBB) surface sediments. These organic compounds represent phytoplanktonic, zooplanktonic, bacterial, archaeal, terrestrial, and fossil carbon sources. The lipids include long-chain n-alkanes, fatty acids (as FAMEs), n-alcohols, C30 mid-chain ketols and …
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Sediment Provenance of Tsunami Deposits: Implications for Assessing the Relative Intensity of Paleotsunamis from the Sendai Coastline of Japan
… like the 2011 event. This study utilizes surface distributions of foraminifera from coastal and offshore locations within Sendai Bay to determine the provenance for 2011 Tohoku tsunami sediments preserved within rice fields on the Sendai Plain near the towns of Yamamoto, Shinchi, and …
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