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 10 of 10 for “"Carbonate ion"”.
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Reconstructing Surface Water Carbonate Ion Concentration Changes in the Eastern Equatorial Pacific Across Glacial Transitions
… atmosphere, but recent studies suggest the region may shift to a sink for atmospheric CO<sub>2</sub> under different climate states. Here, I focus on two transitional periods, the last deglaciation (25 kyr to present) and last glaciation (the Marine Isotope Stage (MIS) 5a-4 transition, 96 to 60 …
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Sulfate in foraminiferal calcium carbonate : investigating a potential proxy for sea water carbonate ion concentration
… for measuring sulfur in foraminiferal calcium carbonate was developed, employing a high-resolution inductively coupled plasma-mass spectrometer. The sulfur measurements, expressed as sulfur-to-calcium (S/Ca) ratios in the foraminiferal shells, ranged from 0.26 to 6.0 mmol/mol. Most analyses …
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A study of the remineralization of organic carbon in nearshore sediments using carbon isotopes
A study of the remineralization of organic carbon was conducted in the organic-rich sediments of Buzzards Bay, MA. Major processes affecting the carbon chemistry in sediments are reflected by changes in the stable carbon isotope ratios of dissolved inorganic carbon (ΣCO2) in sediment pore water. …
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A study of the remineralization of organic carbon in nearshore sediments using carbon isotopes
A study of the remineralization of organic carbon was conducted in the organic-rich sediments of Buzzards Bay, MA. Major processes affecting the carbon chemistry in sediments are reflected by changes in the stable carbon isotope ratios of dissolved inorganic carbon (XCO2) in sediment pore water. …
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Seasonal and interannual variability of the marine carbonate system at the ice shelf in the eastern Weddell Gyre and its sensitivity to future ocean acidification
Ocean Acidification through the uptake of anthropogenic CO₂ is resulting in a decrease in surface water carbonate ion concentration, a critical compound for marine calcifying organisms (Fabry et al., 2008; Orr et al., 2005). Natural seasonal variability is predicted to hasten the effects of Ocean …
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Climate proxies in planktic foraminifera: Environmental or biomineralisation controls?
… time. However, the proxy-environment correlations often vary among species and individuals, indicating different degrees of biological control during calcification. This introduces significant uncertainties in their interpretation. To improve the reliability of foraminiferal proxies, it is …
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Zinc and cadmium in benthic foraminifera as tracers of ocean paleochemistry
… tools for reconstructing nutrient distributions, and thus ocean circulation, on glacial-interglacial timescales. However, each tracer has its own "artifacts" that can complicate paleoceanographic interpretations. It is therefore advantageous to measure multiple nutrient proxies with the aim …
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Zinc and cadmium in benthic foraminifera as tracers of ocean paleochemistry
… tools for reconstructing nutrient distributions, and thus ocean circulation, on glacial-interglacial timescales. However, each tracer has its own "artifacts" that can complicate paleoceanographic interpretations. It is therefore advantageous to measure multiple nutrient proxies with the aim …
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Constraining Respired Carbon Storage in the Eastern Tropical Pacific Over the Last 25 Thousand Years Using Benthic Foraminiferal Boron/Calcium Ratios
… atmospheric CO<sub>2</sub> concentrations (Broecker and Barker 2007; Sigman et al., 2010). A recent study by Loveley et al. (2017) showed that sedimentary authigenic uranium (aU) concentrations, a proxy for suboxic bottom-water conditions, increased significantly in the Eastern …
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A novel view on the early stage of crystallization
… a novel view on the early stage of crystallization utilizing calcium carbonate as a model system. Calcium carbonate is of great economical, scientific and ecological importance, because it is a major part of water hardness, the most abundant Biomineral and forms huge amounts of geological …