Дисертації з теми "Hydrogen isotopic composition"
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ZNEIMER, STEPHANIA. "Stable isotopic composition of southern Illinois precipitation from (2012-2017) summary." OpenSIUC, 2019. https://opensiuc.lib.siu.edu/theses/2578.
Повний текст джерелаLeshin, Laurie Ann Stolper Edward M. Stolper Edward M. "The abundance and hydrogen isotopic composition of water in SNC meteorites : implications for water on Mars /." Diss., Pasadena, Calif. : California Institute of Technology, 1995. http://resolver.caltech.edu/CaltechETD:etd-11062007-091745.
Повний текст джерелаSnover, Amy Katherine. "The stable hydrogen isotopic composition of methane emitted from biomass burning and removed by oxic soils : application to the atmospheric methane budget /." Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/11570.
Повний текст джерелаBurke, Roger Allen Jr. "Stable Hydrogen and Carbon Isotopic Compositions of Biogenic Methanes." Scholar Commons, 1985. https://scholarcommons.usf.edu/etd/7658.
Повний текст джерелаClog, Matthieu. "Concentration et composition isotopique en hydrogène du manteau terrestre." Paris 7, 2010. http://www.theses.fr/2010PA077209.
Повний текст джерелаConstraining the concentration and isotopic composition of hydrogen in Earth's mantle brings crucial insights on the global water cycle and the nature of mantle heterogeneities. For this purpose, glassy rims of basalts are the best samples. In this study, 170 samples from 4 oceanic ridges and 2 hotspots were analysed for water content and ô D. During this work, we showed that using platinum crucibles to extract the volatiles was the cause of an analytical bias in earlier data. The use of silicate tubes was thus prefered. δ D re-measured on samples previously analyzed using platinum crucibles are, on average, 15%o higher. The δ D and the H2O/Ce ratio are hétérogeneous, both between areas and locally, and caracterize the sources. The source of N-MORB contains 175+/-70 ppm of water and has a δ D of -61+/-6%o. MORB from the Altantic ocean are richer in water (-250 ppm in the source) and D ( δ D—57%o), than those from thé South-East Indian (H2O~140 ppm and δ DS\simS-63%o), illustrating different mixing processes, also seen through the Pb/Ce ratios. The study of the MORB from the South-West Indian ridge showed that δ D and H2O/Ce are sensitive to metasomatism. The concentrations of water in E-MORB and OIB sources are higher and more variable (from 250 to 700 ppm). The ô D of water- and incompatible elements-enriched sources range from -70 to -40%o, showing as much variations as depleted sources. Confrontation with the isotopic compositions of Ne, Pb, Sr and Nd shows that the resevoir containing the primitive rare gases cannot be water-rich, and is thus different from the FOZO. Therefore, efficient recycling of water with no modification of its isotopic composition in hydrogen at subdcution zone can occur at some subduction zones
Bates, Benjamin R. "Within Lake Spatial Variability of Long-chain n-alkanes and their Hydrogen Isotopic Compositions Adirondack Mountains, NY." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1535373859284956.
Повний текст джерелаDawson, Daniel. "Stable hydrogen isotope ratios of individual hydrocarbons in sediments and petroleum." Thesis, Curtin University, 2006. http://hdl.handle.net/20.500.11937/1237.
Повний текст джерелаDawson, Daniel. "Stable hydrogen isotope ratios of individual hydrocarbons in sediments and petroleum." Curtin University of Technology, Department of Applied Chemistry, 2006. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=16839.
Повний текст джерелаThe δD values of the n-alkanes also reflect their multiple source inputs. For example, a saw-toothed profile of n-alkane δD values in Australian torbanites is attributed to a dual-source system: a predominant B. braunii input, with a minor terrestrial plant input to odd-carbon-numbered n-alkanes in the range n-C20 [subscript] to n-C29 [subscript]. The δD values of n-alkanes and isoprenoids (pristane and phytane) differ significantly in two Permian torbanites from Australia, thought to be reflective of the offset between the δD values of their precursors in extant organisms. The torbanite data indicate that a biological δD signal has been preserved for at least 260–280 million years, extending the utility of δD values for palaeoclimate studies. To elucidate the effect of sedimentary processes on the δD values of petroleum hydrocarbons, three sedimentary sequences have been studied. These comprise one from the Perth Basin (Western Australia) and two from the Vulcan Sub-basin (northern Australia) covering a wide range of maturities, i.e. 0.53–1.6% vitrinite reflectance (Ro). The δD values of n-alkanes extracted from immature-early mature sediments (marine shales/siltstones and mudstones) are consistent with that expected of marine-derived n-alkyl lipids. The hydrocarbons become enriched in D with increasing maturity. The large (ca. 115%) biologically-derived offset between the δD values of n-alkanes and acyclic isoprenoids from immature sediments gradually decreases with increasing maturity, as the isoprenoids become enriched in D more rapidly than the n-alkanes. The D-enrichment in isoprenoids correlates strongly with Ro and traditional molecular maturity parameters.
This suggests that H/D exchange during maturation occurs via a mechanism involving carbocation-like intermediates, which proceeds more rapidly with compounds containing tertiary carbon centres. Significant epimerisation of pristane and phytane coincides with their D-enrichment, suggesting that hydrogen exchange occurs at their tertiary carbons. A mechanism is proposed which can account for both H/D exchange and the epimerisation of pristane and phytane in the sedimentary environment. Pristane and phytane extracted from a post-mature sediment from the Paqualin-1 sequence are significantly enriched in D (ca. 40%) relative to the n-alkanes, indicating that D-enrichment persists at very high maturity, and is more pronounced for the regular isoprenoids than the n-alkanes. This supports the notion that H/D exchange causes the observed shift in δD values, rather than free-radical hydrogen transfer. The differences between the δD values of pristane and phytane show opposite trends in the Perth Basin and Vulcan Sub-basin sediments. In the Perth Basin, phytane is enriched in D relative to pristane, likely due to a dominant algal source. In the Vulcan Sub-basin, pristane is enriched in D relative to phytane, and thus is attributed to a lower relative input of algal organic matter. The variance of the δD values of pristane and phytane is generally consistent throughout the maturity range and provides evidence that pristane and phytane exchange hydrogen at similar rates. δD analysis of crude oils and condensates reservoired in the Perth Basin and Vulcan Sub-basin has been carried out to evaluate potential applications in oil-source correlation.
The n-alkanes from crude oils and condensates are often more enriched in D than n-alkanes extracted from their supposed source rocks, and the oils also show relatively small differences between the δD values of n-alkanes and isoprenoids. These results suggest significant H/D exchange has occurred, implying that the liquids were generated from mature source rocks. A Perth Basin crude oil (Gage Roads-1) thought to be derived from a lacustrine/terrestrial source contains hydrocarbons that are significantly depleted in D relative to Perth Basin oils derived from a marine source, attributed to variability in the isotopic composition of marine and terrestrial source waters. δD values of n-alkanes from Vulcan Sub-basin crude oils and condensates are largely consistent with their prior classification into two groups: Group A, having a marine source affinity; and Group B, having a terrigenous source affinity. Some oils and condensates are suggested to be mixtures of Group A and Group B hydrocarbons, or Group A hydrocarbons and other as yet unknown sources. An exception is a former Group A oil (Tenacious-1) containing n-alkanes that are enriched in D relative to those from other Group A oils and condensates, attributed to mixing with another source of more mature hydrocarbons. The n-alkane δD profile appears to be indicative of source and sedimentary processes. One Perth Basin crude oil (Dongara-14) contains lower-molecular-weight n-alkanes that are depleted in D relative to higher-molecular-weight n-alkanes, attributed to a mixed marine/terrestrial source.
Group A crude oils and condensates from the Vulcan Sub-basin display a ‘bowl-shaped’ profile of n-alkane δD values. An upward inflection in the n-alkane δD profile from n-C11 [subscript] to n-C15 [subscript] is suggested to represent the addition of D-enriched lower-molecular-weight n-alkanes from a more mature wet gas/condensate to an initial charge of lower maturity oil. Ultimately, this project has demonstrated that the δD values of individual petroleum hydrocarbons can be used to elucidate the nature of source organic matter and depositional environments. The preservation potential of lipid δD values is greater than previously thought, although it is clear that H/D exchange accompanying maturation can have a significant effect on the δD values of certain hydrocarbons. Thus, great care must be taken when interpreting δD values of individual hydrocarbons, particularly those derived from sediments of high thermal maturity.
Newberry, Sarah. "Molecular distributions and hydrogen isotopic compositions of n-alkanes from field studies of tree species : applications for paleoclimate studies." Thesis, University of East Anglia, 2013. https://ueaeprints.uea.ac.uk/49706/.
Повний текст джерелаJappy, Trevor George. "Compositional dependence of potassium-argon ages and hydrogen and oxygen stable isotopes in hornblendes from Connemara, Western Ireland." Thesis, University of Glasgow, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264263.
Повний текст джерелаHamilton, Bryan T. "Small Mammals in portions of Great Basin National Park Susceptible to Groundwater Withdrawal: Diversity and Stable Isotope Perspectives." BYU ScholarsArchive, 2009. https://scholarsarchive.byu.edu/etd/1705.
Повний текст джерелаDefouilloy, Céline. "Le rapport isotopique de l'hydrogène dans les météorites de fer." Paris, Muséum national d'histoire naturelle, 2012. http://www.theses.fr/2012MNHN0009.
Повний текст джерелаIrons meteorites are generally considered as remains of differentiated planetesimal cores. Yet, there are still some uncertainties regarding their formation. One proxy that could be used to confirm or not the different hypothesis regarding the formation of Iron meteorites is the Hydrogen isotopic ratio. Indeed, the Hydrogen isotopic ratio varies according to the bearing species and the process that had happened on the parent bodies. The Hydrogen isotopic ratio, as well as its concentration, have been measured in several Iron meteorites using an ion microprobe IMS 3f. Hydrogen isotopic ratios vary from 93 ± 9 to 126 ± 11 x10-6, while the concentrations vary from 0,5 ± 0,1 ppb to 120 ± 130 ppb. Two groups can be distinguished in regard of the concentrations. The magmatic irons have a very low H content while the non-magmatic irons are systematically richer in H
Aboglila, Salem Abdulghni-O. "Organic and isotopic geochemistry of source-rocks and crude oils from the East Sirte Basin (Libya)." Thesis, Curtin University, 2010. http://hdl.handle.net/20.500.11937/2118.
Повний текст джерелаMischler, John A. Alley Richard B. Sowers Todd A. "Carbon and hydrogen isotopic composition of methane over the last 1000 years." 2009. http://etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-3646/index.html.
Повний текст джерелаLeshin, Laurie Ann. "The abundance and hydrogen isotopic composition of water in SNC meteorites : implications for water on Mars." Thesis, 1995. https://thesis.library.caltech.edu/4424/1/Leshin_la_1995.pdf.
Повний текст джерелаKaushal, Ritika. "Stable Isotopic Composition of Rice Grain Organic Matter as an Archive of Monsoonal Climate." Thesis, 2015. http://etd.iisc.ernet.in/2005/3995.
Повний текст джерелаKaushal, Ritika. "Stable Isotopic Composition of Rice Grain Organic Matter as an Archive of Monsoonal Climate." Thesis, 2017. http://etd.iisc.ac.in/handle/2005/4019.
Повний текст джерелаKaushal, Ritika. "Stable Isotopic Composition of Rice Grain Organic Matter as an Archive of Monsoonal Climate." Thesis, 2017. http://etd.iisc.ernet.in/2005/3996.
Повний текст джерелаNiedermeyer, Eva Maria [Verfasser]. "Northwest African Sahel climate variations during holocene, late pleistocene : insights from plant wax stable hydrogen (δD) and carbon (δ13C) isotopic composition and sea-surface temperature / Eva Maria Niedermeyer". 2009. http://d-nb.info/999446169/34.
Повний текст джерелаDar, Shaakir Shabir. "On the spatio-temporal distribution of stable isotope ratios in the hydrological cycle over India and the Southern Ocean." Thesis, 2020. https://etd.iisc.ac.in/handle/2005/4353.
Повний текст джерелаZhou, Youping. "Carbon, oxygen and hydrogen isotope compositions of plant material : insights from controlled growth experiments and modelling." Phd thesis, 2005. http://hdl.handle.net/1885/150224.
Повний текст джерелаChuang, Kai-Hsun, and 莊凱勳. "Hydrogen, Oxygen, and Carbon Isotope Compositions of Meteoric Waters in Feitsui Reservoir and Its Watershed, in Northern Taiwan." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/e9qqfe.
Повний текст джерела國立中央大學
水文所
94
Feitsui Reservoir provides water supply in Taipei City as well as parts of Taipei County in northern Taiwan. The variations of hydrogen, oxygen, and carbon isotope compositions of waters record the sources and mixtures of waters; they are ideal and important tools to study hydrology. This study discussed the relationships among the waters in Feitsui Reservoir, rain waters and river in its watershed in order to provide basic isotope information in hydrology for the appropriate water resource management. From April 2003 to April 2004, rain waters of respective rainy days were collected at Feitsui Reservoir; waters of the reservoir and major branches of its watershed were also sampled monthly. These water samples were analyzed for hydrogen, oxygen, and carbon isotope compositions. In addition, information of meteorology and hydrology was also compiled and integrated with isotope data to study the hydrology cycle of Feitsui Reservoir. Analytical results showed that the hydrogen and oxygen isotope compositions of rain waters in Feitsui Reservoir exhibit a negative correlation with air temperature; an opposite feature with those observed in the continent. Apparently, the variations of hydrogen and oxygen isotope compositions of the rain waters in Feitsui Reservoir’s watershed have been primarily affected by the air masses of different seasons rather than the air temperature; because the sources and the paths of air masses change with seasons and cause distinct isotope fractionations accordingly. Two intervals (southwest and northeast monsoons) were differentiated to discuss the meteoric water lines in this study. Southwest monsoon prevails from May to September, and the ranges of δ18O and δD were -0.7‰ ~ -11.7‰ and1.1‰ ~ -87.4‰, respectively; the least-squares regression line was: �n�n �n�n�n�n�n�n�n�n�n�n�n�n�n�n�n�n�n�n�n�n�n�n�n�n�n�n�n�n�n�n�n�n�n�n�n�n�n�nNortheast monsoon prevails from October to March, and the ranges of δ18O and δD were 0.6‰ ~ -6.2‰ and 20.5‰ ~ -38.4‰, respectively; the least-squares regression line was: .Over this study period, the least-squares regression line of all precipitation data was: . The hydrogen and oxygen isotope compositions of the river waters in Feitsui Reservoir’s watershed showed significant and systematic discrepancy with those of rain waters. The isotope data of rain samples were processed as five-month moving average and weighted according to the precipitation amount. The resulting trends of processed rain waters showed similar seasonal pattern with those of river waters probably due to the hysteresis effect of rain infiltration. The isotopic ranges of the river waters were relatively smaller and depleted than those of the precipitation. The possible causes are: (1) Rain waters had a larger precipitation amount effect in summer with relatively depleted isotope signatures and higher amount of infiltration; (2) The isotope compositions of the rain waters have an altitude effect that provides relatively depleted isotope values at higher locations; (3) The isotope compositions of the rain waters for previous years might carry relatively depleted isotope values. The main source of the Reservoir derives from upstream branch waters, and base flows of those branches are groundwaters after rain infiltration. The observed seasonal isotope fluctuations of base flows were small, δ18O ranging from -4.7‰ to -8.3‰ with a mean value of -5.8‰. On the other hand, the overland flow displayed a large impact on the isotope compositions of the Reservoir during the typhoon periods. For example, the lowest δ18O (-8.3‰) value was detected in the middle water layer of the Feitsui Reservoir after the typhoon of September 2003. The dissolved δ13C values of water samples ranged from -11.7‰ to -16.0 ‰, with relative enriched compositions in June and depleted values in March. The main cause of this season discrepancy is due to the higher growth of algae in June, which absorbed the lighter carbon, leaving the water carbon isotope relatively enriched. The chlorophyll reduced significantly after July with carbon dioxide continually introduced from respiration, resulting lighterδ13C values in the reservoir. In short, results of this work demonstrated that hydrogen, oxygen, and carbon isotope compositions are good tracers in studying hydrology. These isotope tracers not only can effectively explain the sources and mixtures from various sources in Feitsui Reservoir but also enhance our understanding of the hydrology cycle in its watershed and the close relationship between the biology and geochemistry. The isotope data collected in this study are also valuable in the management of the Feitsui Reservoir waters in terms of quality and quantity.