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 “"Triple-oxygen"”.
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Triple oxygen isotope measurements in chert: insights into the Snowball Earth glaciations
… for the trajectory of life, atmospheric oxygen, and planetary habitability. There remains a myriad of questions about the dynamics of these global glaciations, especially regarding the relationship between the cryosphere and hydrosphere during this time. This study analyzes silica …
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Triple oxygen isotope measurements by tunable infrared laser direct absorption spectroscopy, and applications to ratite eggshell
… for highprecision measurement of the three oxygen isotopes directly in CO2 samples using Tunable Infrared Laser Direct Absorption Spectroscopy (TILDAS). After the introduction and optimization of both the sample preparation and analytical systems, it is applied to fossil ratite eggshell …
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Triple oxygen isotopes and oxygen/argon ratio measurements to enhance coastal and open ocean production/respiration comparisons
… study presents in situ measurements of gross oxygen production (G) derived from triple oxygen isotope analysis and of net community oxygen production (N) derived from O2/Ar ratios at station L4, which is part of the Western English Channel Observatory (WECO) and a latitudinal transect through …
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Ecosystem metabolism in salt marsh tidal creeks and ponds : applying triple oxygen isotopes and other gas tracers to novel environments
… This thesis describes new methods to apply the triple oxygen isotope tracer of photosynthetic production in a salt marsh. Additionally, noble gases are applied to constrain air-water exchange processes which affect metabolism tracers. These stable, natural abundance tracers complement …
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Ecosystem metabolism in salt marsh tidal creeks and ponds : applying triple oxygen isotopes and other gas tracers to novel environments
… This thesis describes new methods to apply the triple oxygen isotope tracer of photosynthetic production in a salt marsh. Additionally, noble gases are applied to constrain air-water exchange processes which affect metabolism tracers. These stable, natural abundance tracers complement …
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Constraining air-sea equilibrium and biological end-members for marine gross productivity estimates using oxygen triple isotopes
… errors. A new biogeochemical approach based on triple oxygen isotope measurements in dissolved oxygen (O2) has been developed over the last few years, which allows the derivation of gross productivity integrated over the depth of the mixed layer and the time-scale of O2 gas exchange (Luz & …
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Theory and Utility of the Three Isotope Fractionation Relationship
… of isotope geochemistry began with the study of oxygen isotope geothermometry, most famously for carbonates. Traditionally oxygen isotope studies are only concerned with the relationship between one rare isotope, oxygen-18, and the common isotope, oxygen-16. In these cases, the abundance of the …
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Application of Hydrogen and Oxygen Isotope Ratios of Water to the Study of Evaporation, Palaeoclimate, and Ancient Marine Conditions
Triple-oxygen and hydrogen isotopes of water are critical to aid our understanding of the hydrological cycle on the modern and ancient Earth. As such, this thesis presents advancements in techniques and in the understanding of the isotopic behaviour of water that undergoes evaporation in different …
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Geochemical Approaches to Paleobiology, Paleoclimatology, and Chronostratigraphy of the Cretaceous Cloverly Formation
… of novel isotope proxies such as “clumped” and triple oxygen isotopes.
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New insights into the marine oxygen cycle from manganese oxide minerals and reactive oxygen species
The redox cycling of oxygen between O2, water, and intermediate redox states including hydrogen peroxide and superoxide, has profound impact on the availability and distribution of dissolved O2, the habitability of the marine biosphere, and cellular metabolic and physiological reactions that …
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Isotope Systematics of Gypsum and its Hydration Water
Triple oxygen and hydrogen isotope analysis of the structurally-bound water in gypsum can provide a direct measure of past hydrologic variability. This thesis presents the development of the water extraction and isotopic measurement procedures, the calculation of the gypsum-water isotope …
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Large contribution of light-dependent oxygen uptake to global O2 cycling
The oxygen triple-isotope composition (Δ′17O = δ′17O - θ × δ′18O) of tropospheric O2 is an important parameter used in mass-balance proxy estimates of gross oxygen productivity in the modern ocean and the global biosphere. We created a chemical reaction network box model of the Δ′17O budget of …