Sökning: "Total organic carbon"

Visar resultat 1 - 5 av 173 avhandlingar innehållade orden Total organic carbon.

  1. 1. Quantity and quality of soil organic matter in permafrost terrain

    Författare :Gustaf Hugelius; Peter Kuhry; Philip Wookey; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; carbon; soil organic matter; soil organic carbon; permafrost; arctic; upscaling; peat plateau; cryoturbation; active layer; thermokarst; carbon nitrogen ratio; stable isotopes; humification; Physical geography; Naturgeografi; geografi med naturgeografisk inriktning; Physical Geography;

    Sammanfattning : High latitude terrestrial ecosystems are considered key components in the global carbon (C) cycle and hold large reservoirs of soil organic carbon (SOC). Much of this is stored as soil organic matter (SOM) in permafrost soils and peat deposits and is vulnerable to remobilization under future global warming. LÄS MER

  3. 2. Carbon Emissions from Western Siberian Inland Waters

    Författare :Svetlana Serikova; Jan Karlsson; Oleg S. Pokrovsky; Hjalmar Laudon; Peter Raymond; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; carbon; carbon dioxide; methane; carbon emissions; river; lake; inland waters; permafrost; Siberia; Limnology; limnologi;

    Sammanfattning : Inland waters (i.e. rivers, streams, lakes, ponds) emit carbon (C) into the atmosphere. The magnitude of global inland water C emission has been estimated to equal the global ocean C sink, thus making inland waters an important component of the global C cycle. LÄS MER

  4. 3. Impacts of global change on primary production in northern lakes

    Författare :Isolde Callisto Puts; Ann-Kristin Bergström; Jenny Ask; Tom H. Andersen; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Primary production; global change; warming; browning; lake; carbon dioxide; organic carbon; inorganic carbon; boreal; arctic; DOC; DIC; CO2; allochthonous organic carbon; benthic; periphyton; environmental change; miljöförändringar; environmental science; miljövetenskap; biology; biologi; climate change; klimatförändringar;

    Sammanfattning : Algae are primary producers, a major component of the aquatic foodweb, and changes in primary production affect aquatic ecology in general. Global changes such as warming, recovery of acidification and changes in land-use have caused warming and browning of northern lakes. LÄS MER

  5. 4. Soil organic carbon in permafrost terrain : Total storage, landscape distribution and environmental controls

    Författare :Gustaf Hugelius; Peter Kuhry; Jan Boelhouwers; Stockholms universitet; []
    Nyckelord :;

    Sammanfattning : High latitude terrestrial ecosystems are considered key components in the global carbon (C) cycle and hold large reservoirs of soil organic carbon (SOC). To a large degree, this SOC is stored in permafrost soils and peatlands and is vulnerable to remobilization under future global warming and permafrost thawing. LÄS MER

  7. 5. Natural products from nonracemie building blocks : synthesis of pine sawfly pheromones

    Författare :Michael Larsson; Torbjörn Norin; Gunnar Westman; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Organic chemistry; Total synthesis; diastereoselective addition; dimethylzinc; Lewis acid; alkyllithium; Organisk kemi; Organic chemistry; Organisk kemi;

    Sammanfattning : This thesis describes a number of synthetic approaches for obtaining chiral, enantiomerically pure natural products, in particular some semiochemicals. This has been accomplished by using various strategies; by starting from compounds from the chiral pool, by using chiral auxiliaries, via enzymatic resolutions or by chemical asymmetric synthesis. LÄS MER