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 12 of 12 for “"Stable isotopic composition"”.
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The content and stable isotopic composition of carbon in spherical micrometeorites
… spectrometer is its ability to make accurate isotopic abundance measurements of the blank contribution for the purpose of making corrections to the analytical data. The instrument and inlet system has been applied to studies of micrometeorites >200∝m in diameter.<br></br><br></br>A procedure …
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An investigation of the combined stable isotopic composition of methane emissions from northern wetlands
… sources of methane is still poorly defined. Stable isotope measurements are increasingly being used to constrain global budgets of atmospheric trace gases because isotopic analysis provides a much clearer picture of global atmospheric chemistry than CH<sub>4</sub> concentration measurements …
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Precipitation amount, altitude, and moisture trajectory effects on the stable isotopic composition of precipitation in the Galapagos Islands
Understanding how climate processes facilitate stable water isotope variability in precipitation over time and space is critical to interpreting stable isotope-based paleoclimate proxies, particularly in the eastern equatorial Pacific where stable water isotope observations from precipitation …
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Inference of ecology from the ontogeny of microfossils
… subjected to careful morphological analysis; the stable-isotopic composition of the growth stages revealed that both species inhabit the upper fifty meters of the ocean, descending to deeper water (75-l00m) for the emplacement of an enveloping calcite crust. The third chapter shows a simple …
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Estimation of evaporation losses based on stable isotope composition of water in the Calueque-Oshakati canal, Namibia
… the estimation of evaporation losses using the stable isotopic composition of water in the canal. The study aimed at estimating the amounts of water lost from the Calueque-Oshakati canal due to evaporation against the amounts supplied to the lower Cuvelai-Etosha Basin (CEB) in Namibia. The water …
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Geochemical and isotopic variations in surface waters of the monongahela river basin: An area of accelerating marcellus shale development in West Virginia
… major and minor geochemistry, as well as stable isotopes of delta2HH2O, delta18OH2O, delta13CDIC, delta18OSO4 and delta34SSO4. The geochemical and isotopic characteristics of the 50 water samples collected show no clustering based on production category. Extremely high concentrations of …
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Biogeochemistry and inorganic geochemistry as indicators of the paleoenvironment and paleohydrology of the Al-Azraq Basin, Jordan
… meters of cored playa and lacustrine sediments. Stable isotopic composition of bulk organic matter and carbonate are the main proxies in addition to results from supporting methodologies including: grain size analysis, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Based on the …
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A multi-scale assessment of aquatic ecosystem processes across the land-ocean-atmosphere continuum: from headlands to the sea
… the analysis of lignin phenols and elemental stable isotopic composition. Compositional parameters in the Pacific Northwest revealed patterns of constituent mobilization from deep and shallow soil pools, whereas compositional variability in Espirito Santo revealed functionalization of unique …
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Lakes and Groundwater of the Rieti Basin, Central Italy: Hydrochemistry, Paleolimnology, and Seismologic Influences
… and adjacent groundwater springs. Chemical and stable isotopic tracers were used to characterize water samples and to examine downcore changes in sediment cores. The lakes, Lungo and Ripasottile (LUN and RIP) have been described as surface outcroppings of the groundwater table, yet the …
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Plant organic matter mobilization and export in fluvial systems
… of this thesis focusses on the applicability of stable isotope records such as plant wax n-alkanes in sediment archives as qualitative and quantitative proxy for the variability of past Indian Summer Monsoon (ISM) strength. First, I determined how ISM strength affects the hydrogen and oxygen …
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Spatial and temporal variations in the geometry and composition of the Permian Whitehill Formation South Africa
… variability in its stratigraphy and composition, particularly the distribution of its organic carbon content across the basin. Because these stratigraphic variations and compositional heterogeneities remained largely uninvestigated, there are conflicting interpretations of not only …
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Stable isotopic insight into pelagic carbon cycling in Loch Lomond: a large, temperate latitude lake.
… pelagic production in Loch Lomond, Scotland. Stable isotopic composition of dissolved inorganic carbon (DIC), dissolved oxygen (DO), dissolved organic carbon (DOC) and total dissolved nitrogen (TDN), along with their respective concentrations, were measured in a temporal and spatial survey. …