Sökning: "nitrogen loss"

Visar resultat 1 - 5 av 93 avhandlingar innehållade orden nitrogen loss.

  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 :NATURVETENSKAP; NATURAL SCIENCES; biogeochemistry; nitrogen cycling; nitrogen fixation; cyanobacteria; Baltic Sea; Marine Ecology; marin ekologi;

    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

  2. 2. 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

  3. 3. 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

  4. 4. Microstructure and properties of welds in the lean duplex stainless steel LDX 2101

    Författare :Elin M. Westin; John Ågren; Hannu Hänninen; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Duplex stainless steel; welding; HAZ; nitrogen; manganese; microstructure; austenite formation; phase balance; precipitates; element distribution; segregation; depletion; solidification; pitting corrosion resistance; solidification; element loss; evaporation; deposition; weld oxide; thermo-mechanical simulation; thermodynamic modelling; EPMA; XPS; post-weld cleaning; pickling; Metallurgical process and manufacturing engineering; Metallurgisk process- och produktionsteknik;

    Sammanfattning : Duplex stainless steels can be very attractive alternatives to austenitic grades due to their almost double strength at equal pitting corrosion resistance. When welding, the duplex alloys normally require addition of filler metal, while the commodity austenitic grades can often be welded autogenously. LÄS MER

  5. 5. Welds in the lean duplex stainless steel LDX 2101 : effect of microstructure and weld oxides on corrosion properties

    Författare :Elin M. Westin; John Ågren; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Duplex stainless steel; welding; weld metal; HAZ; nitrogen; manganese; austenite formation; phase balance; precipitates; pitting resistance; heat input; solidification; element loss; evaporation; deposition; weld oxides; discoloration; mechanical properties; thermo-mechanical simulation; Geeble; GTA; laser; LOM; SEM; EDS; TEM; Leco; EPMA; ferroxyl test; XPS; post weld cleaning; pickling; Materials science; Teknisk materialvetenskap;

    Sammanfattning : Duplex stainless steels are a very attractive alternative to austenitic grades due to their higher strength and good corrosion performance. The austenitic grades can often be welded autogenously, while the duplex grades normally require addition of filler metal. LÄS MER