Search for dissertations about: "oxygen isotope"
Showing result 21 - 25 of 54 swedish dissertations containing the words oxygen isotope.
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21. Deposit-feeding in benthic macrofauna : Tracer studies from the Baltic Sea
Abstract : A low content of organic matter, which is largely refractory in nature, is characteristic of most sediments, meaning that aquatic deposit-feeders live on a very poor food source. The food is derived mainly from sedimenting phytodetritus, and in temperate waters like the Baltic Sea, from seasonal phytoplankton blooms. READ MORE
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22. Mechanisms for Solvolytic Elimination and Substitution Reactions Involving Short-lived Carbocation Intermediates
Abstract : Solvolysis reactions of a range of tertiary substrates in largely aqueous solvents were studied in such respects as β-deuterium kinetic isotope effects, linear free energy relationships and stereochemistry.Solvolysis of the fluorene derivatives 9-methyl–9-(2´-X-2´-propyl)fluorene (1-X, X = Cl, Br, OOCCF3) involves a very short-lived carbocation intermediate. READ MORE
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23. The global marine carbon system through time
Abstract : Carbon dioxide is an important greenhouse gas and in order to understand its effect on the climate we need to identify its sources and sinks. This thesis focuses on different aspects of the marine carbon system and the exchange of carbon between the ocean and the atmosphere. READ MORE
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24. Fluid-induced alteration of metasedimentary rocks in the Scottish Highlands
Abstract : Fluids, mainly H2O and CO2, are released from H- and C-bearing phases during prograde metamorphism. Because of the buoyancy of these fluids, they rise within the crust towards the surface of the Earth. Metamorphic fluids take advantage of permeable horizons, shear zones, fold hinges, fractures, and are channelled into high-flux zones. READ MORE
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25. The role of benthic macrofauna in nitrogen cycling in eutrophic lake sediment
Abstract : This thesis concerns the role of sediment-living macrobenthos in the cycling of nitrogen species and nitrogen transformation in eutrophic freshwater sediments. In my thesis I have, employing 15N-isotope techniques in laboratory experiments, shown the importance of infaunal chironomid larvae and oligochaetes on denitrification in eutrophic lake sediments. READ MORE