Sökning: "lake sediments"

Visar resultat 21 - 25 av 140 avhandlingar innehållade orden lake sediments.

  1. 21. The role of benthic macrofauna in nitrogen cycling in eutrophic lake sediment

    Författare :Jonas Martin Svensson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; nitrogen retention; nitrous oxide; oligochaetes; chironomids; mineralisation; nitrification; denitrification; eutrophic; sediment; lake; Macrofauna; nitrogen cycling; fish reduction.; Ecology; Ekologi;

    Sammanfattning : This thesis concerns the role of sediment-living macrobenthos in the cycling of nitrogen species and nitrogen transformation in eutrophic freshwater sediments. In my thesis I have, employing 15N-isotope techniques in laboratory experiments, shown the importance of infaunal chironomid larvae and oligochaetes on denitrification in eutrophic lake sediments. LÄS MER

  3. 22. The character of magnetic records of deformed soft sediments with emphasis on liquefaction structures

    Författare :Guangyu Sun; Nils Axel Mörner; Don Tarling; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magnetism; sediments; deformation; Earth sciences; Geovetenskap;

    Sammanfattning : In this thesis the characteristics of magnetic records in deformed soft sediments during postglacial time in Sweden are studied. Magnetic records refer in this study to magnetic remanence (NRM and ChRM) and susceptibility, including its anisotropy (AMS). LÄS MER

  4. 23. Local and global contaminants in Swedish waters : studies on PCBs, DDTs, 4,5,6-trichloroguaiacol and their transformation products in fish and sediments

    Författare :Maria Söderström; Åke Bergman; Bert van Bavel; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; PCB; DDT; HCB; trichloroguaiacol; transformation products; dimerisation; bromination; environmental pollutants; eutrophication; lakes; fresh water; baltic sea; monitoring; sediments; fish; phytoplankton; PCB; DDT; HCB; triklorguajakol; omvandlingsprodukter; dimerisering; bromering; miljöföroreningar; eutrofiering; sjöar; sötvatten; östersjön; miljöövervakning; sediment; fisk; fytoplankton; miljökemi; Environmental Chemistry;

    Sammanfattning : This thesis is focused on studies on the environmental fate and methodological improvements for determination of the global contaminants, PCBs and DDTs, and locally discharged phenolics, e.g. 4,5,6-trichloroguaiacol (4,5,6-TCG), and their transformation products. LÄS MER

  5. 24. Diatom stratigraphy and evidence of Holocene environmental changes in selected lake basins in the Antarctic and South Georgia

    Författare :Anders Wasell; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Holocene; Antartica; Antarctic Peninsula; South Georgia; lakes; lake sediments; stratigraphy; diatoms; radiocarbon dates; Quaternary Geology; kvartärgeologi;

    Sammanfattning : .... LÄS MER

  7. 25. Mobile phosphorus in lake sediments, sludge and soil : A catchment perspective

    Författare :Emil Rydin; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; Biologi; Biology; Biologi; limnologi; Limnology;

    Sammanfattning : Phosphorus (P), a key element in lake primary production and eutrophication, is accumulating in agricultural soil, urban landfills and lake sediments. This accumulation increases the risk for non-point losses of P to ground- and surface waters. LÄS MER