Sökning: "nitrogen"

Visar resultat 1 - 5 av 1018 avhandlingar innehållade ordet nitrogen.

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

    Detta är en avhandling från Stockholm : Department of Ecology, Environment and Plant Sciences, Stockholm University

    Författare :Isabell Klawonn; Stockholms universitet.; [2015]
    Nyckelord :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

    Detta är en avhandling från ; Chalmers tekniska högskola; Gothenburg

    Författare :Rasmus Einarsson; [2017]
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL 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. Riverine nitrogen : Analysis and modelling under Nordic conditions

    Detta är en avhandling från Linköping : Tema, Linköpings universitet

    Författare :Berit Arheimer; Linköpings universitet.; Linköpings universitet.; [1999]
    Nyckelord :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

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

    Detta är en avhandling från Stockholm : Department of Ecology, Environment and Plant Sciences, Stockholm University

    Författare :Jennie B. Svedén; Stockholms universitet.; [2016]
    Nyckelord :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

  7. 5. Nitrogen removal in treatment wetlands Factors influencing spatial and temporal variations

    Detta är en avhandling från Institutionen för fysik, kemi och biologi

    Författare :Sofia Kallner Bastviken; Linköpings universitet.; Linköpings universitet.; [2006]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Wetlands; denitrification; macrophytes; nitrogen; nitrification; model; treatment wetlands; potential denitrification; NATURAL SCIENCES Biology; NATURVETENSKAP Biologi;

    Sammanfattning : Decreasing the nitrogen transport from land to surrounding seas is a major task throughout the world to limit eutrophication of the coastal areas. Several approaches are currently used, including the establishment of wetlands, to decrease the transport of nitrogen. LÄS MER