Sökning: "Dual isotope"

Visar resultat 1 - 5 av 11 avhandlingar innehållade orden Dual isotope.

1. 1. Isotopes as Mechanism Spies : Nucleophilic Bimolecular Substitution and Monoamine Oxidase B Catalysed Amine Oxidation Probed with Heavy Atom Kinetic Isotope Effects

   Författare :Susanna MacMillar; Olle Matsson; Anita Hussénius; Daniel M. Quinn; Uppsala universitet; []
   Nyckelord :Organic chemistry; nucleophilic bimolecular substitution SN2; kinetic isotope effects; precision conductometry; monoamine oxidase B MAO B; reaction mechanism; carbon 11C 14C kinetic isotope effect; ion pairing triple-ion formation; para-substituted benzyl chlorides; tetrabytylammonium cyanide; Organisk kemi;

   Sammanfattning : This thesis concerns the study of reaction mechanisms by means of kinetic isotope effects (KIEs). Studies of the nucleophilic bimolecular substitution (SN2) reaction had the dual purpose of improving our fundamental understanding of molecular reactivity and assessing the ability of kinetic isotope effects to serve as mechanistic tools. LÄS MER

3. 2. Dual isotope (13C-14C) Studies of Water-Soluble Organic Carbon (WSOC) Aerosols in South and East Asia

   Författare :Elena N. Kirillova; Örjan Gustafsson; Maria Cristina Facchini; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; atmospheric aerosols; water-soluble organic carbon; carbon isotopes; South Asia; East Asia; source apportionment; aerosol aging; Applied Environmental Science; tillämpad miljövetenskap;

   Sammanfattning : Atmospheric aerosols may be emitted directly as particles (primary) or formed from gaseous precursors (secondary) from different natural and anthropogenic sources. The highly populated South and East Asia regions are currently in a phase of rapid economic growth to which high emissions of carbonaceous aerosols are coupled. LÄS MER

4. 3. Palaeodiet and Infant Feeding in Coastal Arctic Settlements : Insights from stable isotope analysis of bone and dentine collagen and amino acids

   Författare :Alison Harris; Gunilla Eriksson; Kerstin Lidén; Michelle Alexander; Tamsin O'Connell; Stockholms universitet; []
   Nyckelord :HUMANIORA; HUMANITIES; Arctic; palaeodiet; Inuit; Yup’ik; infant feeding; domestic dogs; amino acids; collagen; stable isotopes; maintenance activities; gender; arkeologi med inriktning mot laborativ arkeologi; Scientific Archaeology;

   Sammanfattning : This dissertation investigates the day-to-day activities that sustained human societies in the arctic and subarctic environments of North America and Siberia over the past 1500 years. Maintenance activities, such as food preparation, childcare, and the care of domestic animals, are commonly inflected by social identity and can provide insight into the experience of gender among archaeological and historical populations. LÄS MER

5. 4. Compound-specific bromine isotope analysis of methyl bromide using GC-multiple collector mass spectrometry

   Författare :Axel Horst; Örjan Gustafsson; David Bastviken; Ulla Sellström; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : The isotopic composition of ozone depleting methyl halides may provide valuable information on the sources and sinks of these compounds. However, so far mostly stable carbon isotope analysis of methyl chloride and methyl bromide has been at­tempted. LÄS MER

7. 5. Isotope-based constraints on sources and processing of black carbon, carbon monoxide, and brown carbon in South Asia

   Författare :Sanjeev Dasari; Örjan Gustafsson; August Andersson; Jos Lelieveld; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; South Asia; Air Pollution; Short-Lived Pollutants; Atmospheric Abundance; Model-Observation Mismatch; Radiocarbon; Stable Isotopes; Applied Environmental Science; tillämpad miljövetenskap;

   Sammanfattning : The highly populated South Asian region is facing rapid economic growth and urbanization. Here, both climate- and health-affecting atmospheric agents such as light-absorbing aerosols black carbon (BC) and brown carbon (BrC), trace gas carbon monoxide (CO), are often found in relatively high levels compared to in other regions. LÄS MER