Sökning: "Nitrogen"

Visar resultat 16 - 20 av 1355 avhandlingar innehållade ordet Nitrogen.

  1. 16. Strategic nitrogen management in stockless organic cropping systems : redistribution of residual biomass for improved energy and nitrogen balance

    Författare :Tora Råberg; Sweden SLU; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; bioenergy; biomass management; crop rotation; ecological intensification; green manure; life cycle assessment; nitrogen cycling; organic agriculture; soil incubation; stockless cropping systems;

    Sammanfattning : Agriculture faces the challenge of producing high yields to feed a growing world population, while simultaneously addressing environmental problems such as eutrophication, emissions of greenhouse gases, loss of biodiversity and soil degradation. Organic farming can be part of the solution, as it promotes biodiversity, uses less energy for fertiliser production and often has higher inputs of organic matter to soil than conventional farming. LÄS MER

  2. 17. Nitrogen transformations in wetlands: Effects of water flow patterns

    Författare :Torbjörn Davidsson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Hydrobiology; hydrology; infiltration; subsurface flow; surface flow; wetland; nitrogen; Denitrification; mineralization; nitrification; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi;

    Sammanfattning : In this thesis, I have studied nitrogen turnover processes in watermeadows. A watermeadow is a wetland where water infiltrates through the soil of a grassland field. LÄS MER

  3. 18. Optimization of Pretreatment of Kraft Pulp with Nitrogen Oxides

    Författare :Urban Öjteg; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Kappa number; lignins; Nitric acid; Magnesium; spent liquors; viscosity; softwood; oxygen bleaching; Nitrogen dioxide; Manganese; Oxygen; Nitrogen oxides; pretreatment; Kraft pulp;

    Sammanfattning : Modified kraft pulp subjected to oxygen bleaching following pretreatment with 2% nitrogen dioxide for 140 min with the addition of oxygen resulted in low selectivity after subsequent oxygen bleaching. In contrast, pretreatment in the absence of oxygen removed more than 80% of the lignin after oxygen bleaching and still maintained high selectivity (kappa number less than 5 at viscosity 950 dm3/kg). LÄS MER

  4. 19. Conversion of nitrogen in a fixed burning biofuel bed

    Författare :Jessica I. Samuelsson; RISE; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; biomass; model; fuel nitrogen; fixed bed; nitric oxide; Nitrogen oxides; combustion; measurements; biofuel; grate;

    Sammanfattning : .... LÄS MER

  5. 20. Strategic nitrogen management in stockless organic cropping systems : redistribution of residual biomass for improved energy and nitrogen balance

    Författare :Tora Råberg; RISE; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; bioenergy; biomass management; crop rotation; ecological intensification; green manure; life cycle assessment; nitrogen cycling; organic agriculture; soil incubation; stockless cropping systems;

    Sammanfattning : A griculture faces the challenge of producing high yields to feed a growing world population, while simultaneously addressing environmental problems such as eutrophication, emissions of greenhouse gases, loss of biodiversity and soil degradation. Organic farming can be part of the solution, as it promotes biodiversity, uses less energy for fertiliser production and often has higher inputs of organic matter to soil than conventional farming. LÄS MER