Search for dissertations about: "Carbon and nitrogen isotopes"

Showing result 6 - 10 of 25 swedish dissertations containing the words Carbon and nitrogen isotopes.

  1. 6. Our Bones, who art contaminated : Glues, strontium isotopes, and mobility in early Swedish Christians

    Author : Crista Adelle Wathen; Kerstin Lidén; Sven Isaksson; Christophe Snoeck; Stockholms universitet; []
    Keywords : HUMANIORA; HUMANITIES; Strontium isotopes; contamination; conservation; glues; Christianity; mobility; early Christians; Sweden; Varnhem; Västerhus; bones; teeth; Scientific Archaeology; arkeologi med inriktning mot laborativ arkeologi;

    Abstract : This thesis aims to build upon previous research into contamination and its effects on isotopes by focusing on the strontium isotopic ratio (87Sr/86Sr), which is used in mobility studies to study the movements of past humans and animals and to build past economic trading networks. Contamination is a broad topic, and in the scope of this thesis, it concerns the introduction of contaminants from the soil after interment and the post-excavation preservation efforts. READ MORE

  2. 7. Effects of heavy metal contamination on carbon and nitrogen cycling : An ecological approach to assess risks to soil functions

    Author : Ingrid Rijk; Alf Ekblad; Dan Berggren Kleja; Erik Karltun; Örebro universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; heavy metals; soil contamination; stable isotopes; N cycling microbial guilds; 13C; 15N; nitrification; denitrification; biochar; soil respiration; microbial activity; bioavailability;

    Abstract : Soil contamination with heavy metals may disrupt soil microorganisms with important roles in carbon (C) and nitrogen (N) cycling. However, there is a lack of understanding on how microorganisms are affected in soil, which may lead to a mismatch when assessing risks of contaminants to field soils. READ MORE

  3. 8. An evaluation of the distributions of polychlorinated biphenyls and organic matter in coastal sediments

    Author : Anders Jönsson; Örjan Gustafsson; Detlef Schulz-Bull; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Polychlorinated biphenyls PCBs ; organic carbon; sediment; stable carbon isotopes; Earth sciences; Geovetenskap;

    Abstract : The objective of this thesis is to improve the understanding of what processes and mechanism affects the distribution of polychlorinated biphenyls (PCBs) and organic carbon in coastal sediments. Because of the strong association of hydrophobic organic contaminants (HOCs) such as PCBs with organic matter in the aquatic environment, these two entities are naturally linked. READ MORE

  4. 9. Carbon and nitrogen fluxes associated to marine and estuarine phytoplankton

    Author : Malin Olofsson; Göteborgs universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Nutrient assimilation Stable isotopes Single cell diversity Phytoplankton;

    Abstract : Globally, mainly nitrogen or phosphorus is limiting the primary production. New nitrogen can enter estuarine ecosystems as nitrate from upwelling events, from river runoff, atmospheric deposition, or by nitrogen fixation. READ MORE

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

    Author : Susanna MacMillar; Olle Matsson; Anita Hussénius; Daniel M. Quinn; Uppsala universitet; []
    Keywords : 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;

    Abstract : 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. READ MORE