Sökning: "nitrogen"

Visar resultat 1 - 5 av 1209 avhandlingar innehållade ordet nitrogen.

  1. 1. Marine nitrogen fixation : Cyanobacterial nitrogen fixation and the fate of new nitrogen in the Baltic Sea

    Författare :Isabell Klawonn; Helle Ploug; Lasse Riemann; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; biogeochemistry; nitrogen cycling; nitrogen fixation; cyanobacteria; Baltic Sea; marin ekologi; Marine Ecology;

    Sammanfattning : Biogeochemical processes in the marine biosphere are important in global element cycling and greatly influence the gas composition of the Earth’s atmosphere. The nitrogen cycle is a key component of marine biogeochemical cycles. LÄS MER

  3. 2. Assessing reactive nitrogen flows in European agricultural systems

    Författare :Rasmus Einarsson; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; LANTBRUKSVETENSKAPER; NATURAL SCIENCES; ENGINEERING AND TECHNOLOGY; AGRICULTURAL SCIENCES; food; nitrogen indicator; nitrogen budget; nitrogen; agriculture; nitrogen footprint; uncertainties;

    Sammanfattning : In most ecosystems, nitrogen is a scarce and growth-limiting nutrient. Natural and anthropogenic processes convert unreactive atmospheric dinitrogen (N2) into reactive, bioavailable, nitrogen. LÄS MER

  4. 3. Biological nitrogen fixation : the effect of irridiated nitrogen gas on nitrogen fixation by Azotobacter

    Författare :Bengt Zacharias; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : .... LÄS MER

  5. 4. Riverine nitrogen : Analysis and modelling under Nordic conditions

    Författare :Berit Arheimer; Linköpings universitet; []
    Nyckelord :SOCIAL SCIENCES; SAMHÄLLSVETENSKAP; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; INTERDISCIPLINARY RESEARCH AREAS; TVÄRVETENSKAPLIGA FORSKNINGSOMRÅDEN;

    Sammanfattning : The Baltic Sea in northern Europe is a brackish water body where eutrophication is considered a serious problem, partly as a result of high nitrogen load from rivers. This thesis includes statistical analysis of nitrogen behaviour in 55 small catchments. The results were used for further development of a dynamic model (HBV-N). LÄS MER

  7. 5. Cyanobacterial Nitrogen Fixation in the Baltic Sea : With focus on Aphanizomenon sp

    Författare :Jennie B. Svedén; Jakob Walve; Helle Ploug; Angela Wulff; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; cyanobacteria; Baltic Sea; nitrogen fixation; Aphanizomenon sp.; dissolved nitrogen; particulate nitrogen; sedimentation; marin ekologi; Marine Ecology;

    Sammanfattning : Cyanobacteria are widely distributed in marine, freshwater and terrestrial habitats. Some cyanobacterial genera can convert di-nitrogen gas (N2) to bioavailable ammonium, i.e. perform nitrogen (N) fixation, and are therefore of profound significance for N cycling. LÄS MER