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 20 of 83 for “"isotopic analysis"”.
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Sequential Isotopic Analysis of Ammonite Aptychi
… and biological factors. Previous stable isotopic studies on ammonite aptychi were based on bulk sampling, and thus cannot reveal information about ammonite life history. This thesis reports the first time series δ18O and δ13C values measured in eight ammonite aptychi and assesses their …
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An Isotopic Analysis of Carbon Dynamics in Sphagnum Peat
… dissolved in surface pool water is traced using isotopic analysis as it is oxidised and travels into the interstitial Sphagnum water, through to being photosynthetically captured in α‐cellulose that makes up living Sphagnum, and finally to the carbon stored in layers of peat. Evidence is …
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Hydrology of Bishop Creek, Inyo County, California: An isotopic analysis
… adverse effects on the riparian community. An isotopic study was employed to better understand the hydrology of the basin, estimate the volume of ground-water input along diverted reaches of Bishop Creek, and determine the sources of water to different tree species at various times of the …
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Oxygen stable isotopic analysis of calcite by Raman microprobe spectrometry
The oxygen stable isotopic compositions of minerals give valuable insight into the processes that govern many low- and high-temperature geologic systems. Much research has focused on the ability to analyze the fine-scale oxygen isotopic zonation in many minerals using techniques such as the laser …
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Life in Medieval Cambridge: an isotopic analysis of diet and mobility
… This thesis utilises contextualised isotope analysis of human and faunal skeletal remains from cemetery sites excavated from Cambridge and its hinterlands to investigate what life was like for the population living in the High and Late Medieval period. Isotope sampling focussed on High and …
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Oxygen and hydrogen isotopic analysis of tourmaline by secondary ion mass spectrometry
The O and H isotopic composition of minerals can provide valuable information on the source of the fluids and temperature of mineral precipitation. To obtain accurate isotopic measurements using SIMS, it is important to select chemically similar standards and samples to correct for both matrix …
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GLOBAL ASSESSMENT OF RADIOCARBON ISOTOPIC ANALYSIS FOR PARTICULATE AND DISSOLVED ORGANIC CARBON IN RIVERINE SYSTEMS
<p>Rivers are a significant source of particulate and dissolved organic carbon (POC, DOC) into inland waters and coastal systems and provide a fundamental linkage between the terrestrial, oceanic, and atmospheric carbon reservoirs. Recent studies have examined the relationship between the quantity …
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Planktonic foraminifera in the sea of Okhotsk : population and stable isotopic analysis from a sediment trap
The relationship of planktonic foraminiferal populations and stable isotopes to synoptic sea surface temperatures (SST's) was examined in the Sea of Okhotsk, using sediment trap samples (trap deployed Aug. '90 - Aug. '91; 53°19'N, 149°50'E) and AVHRR satellite sea surface temperature data. Synoptic …
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Planktonic foraminifera in the sea of Okhotsk : population and stable isotopic analysis from a sediment trap
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1996.
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Advances in the isotopic analysis of biogenic phosphates and their utility in ecophysiological studies of aquatic vertebrates
… both marine and freshwater environments. This isotopic approach requires the avoidance of isotopically altered specimens. For this reason, the second component of this work deals with criteria for recognizing isotopically altered fossils. In contrast to one recent study, I found a positive …
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A carbon and nitrogen isotopic analysis of Pleistocene food webs in North America: implications for paleoecology and extinction
Carbon and nitrogen isotopic reconstructions of North American Pleistocene trophic relationships were used to examine the extinction within terrestrial mammals ~10,000 years ago and distinguish between two potential causal mechanisms - human over-hunting and climate change. Additionally, individual …
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Development of separation methods and measurement protocols for Sr and Pb isotopic analysis of archaeological artefacts by means of single-collector and multi-collector ICP-mass spectrometry
This work aimed at studying the isotopic composition of the elements strontium (Sr) and lead (Pb), that are present in low concentrations in a large variety of archaeological artefacts. For isotope ratio analysis, inductively coupled plasma-mass spectrometry (ICP-MS) – a powerful technique for the …
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PARAFFIN: AN ECONOMIC AND ECOLOGICAL ALTERNATIVE FOR BONE CONSERVATION
… were subjected to paraffin treatment and then to isotopic analysis to quantify and investigate the chemical effects of paraffin. Although the results showed that paraffin had a limited impact, the sample size proved too small to display the definitive parameters of paraffin’s effects. The results …
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PARAFFIN: AN ECONOMIC AND ECOLOGICAL ALTERNATIVE FOR BONE CONSERVATION
… were subjected to paraffin treatment and then to isotopic analysis to quantify and investigate the chemical effects of paraffin. Although the results showed that paraffin had a limited impact, the sample size proved too small to display the definitive parameters of paraffin’s effects. The results …
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