Sökning: "isotopes"
Visar resultat 21 - 25 av 307 avhandlingar innehållade ordet isotopes.
21. Collectivity in Neutron-Rich Erbium Isotopes
Sammanfattning : Neutron-rich rare-earth nuclei around the maximum of collectivity are predicted to exist with an extremely stable intrinsic configuration in their ground-state structure. Due to the high degree of axial symmetry and large deformation, these nuclei are also excellent candidates for having long-lived high-K isomers. LÄS MER
22. Fractionation of Fe and Zn isotopes : methods and some applications in aqueous geochemistry
Sammanfattning : Multiple collector inductively coupled plasma mass spectrometry (MC-ICPMS) has been used for the measurement of Fe and Zn isotope ratios in a variety of sample types including natural and synthetic waters, ferromanganese concretions, sediments and biological material. The focus of this PhD study was the development of analytical procedures for precise and accurate measurement of Fe and Zn isotope ratios by high resolution MC-ICPMS. LÄS MER
23. Fractionation of the stable silicon isotopes : analytical method developments and selected applications in geochemistry
Sammanfattning : During the last few decades, variations in the 'natural' isotopic abundances of stable elements (termed 'fractionation') have received considerable interest from the scientific community. Though analytical methods and techniques for the measurement of isotopic abundances with adequate figures of merit have been available for light elements (e.g. LÄS MER
24. Holocene climate and environmental change in high latitudes as recorded by stable isotopes in peat deposits
Sammanfattning : In this thesis, stable carbon and oxygen isotopes in α-cellulose isolated from Sphagnum fuscum moss remains were used as climate proxies. The main focus was to implement the methods in records from high latitude peatlands in the Northern Hemisphere (west-central Canada and north-eastern European Russia), reconstruct palaeoclimate of the studied regions during the Holocene, and evaluate the compatibility of results with other proxy records, especially tree-ring isotope time-series. LÄS MER
25. Iodine Isotopes and their Species in Surface Water from the North Sea to the Northeastern Atlantic Ocean
Sammanfattning : Huge amounts of anthropogenic 129I have been and still are released to the environment through liquid and gaseous discharges from the nuclear fuel reprocessing facilities worldwide and in particular the ones in Europe. Most of this 129I signal has been accumulated in the marine environment which plays a major role in the iodine natural pool. LÄS MER