Sökning: "Nitrogen Cycle"

Visar resultat 41 - 45 av 117 avhandlingar innehållade orden Nitrogen Cycle.

  1. 41. The role of sediments in nitrogen cycling in the larger Baltic Sea

    Författare :Anne Stockenberg; Lars Peter Nielsen; Stockholms universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Microbiology; Mikrobiologi; mikrobiologi; Microbiology;

    Sammanfattning : The eutrophication of coastal areas has become a widespread problem over the last decades. In the Baltic Sea, the input of nitrogen and phosphorus has increased by four and eight times, respectively, since the turn of the century, and this is considered the direct cause of the eutrophication of this ecosystem. LÄS MER

  3. 42. Recycling plant nutrients from waste and by-products : a life cycle perspective

    Författare :Johanna Spångberg; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : Chemical fertilisers contribute to greenhouse gas emissions, fossil fuel use, use of non-renewable phosphate rock and a flow of reactive nitrogen to the biosphere, exceeding the planetary boundaries. Recycling of plant nutrients from waste and by-products from society would reduce the use of chemical fertilisers. LÄS MER

  4. 43. Uptake of and Preference for Nitrate, Ammonium and Amino Acids by Understory Species in Deciduous Forests

    Författare :Magnus Zätterström; Infektionsmedicin; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Soil Science; agricultural hydrology; Lantbrukshydrologi; marklära; Fixation of nitrogen; Kvävefixering; Växtekologi; Plant ecology; wild plants.; understory; rhizosphere; preference; oak forests; NRA; nitrification; nitrate; delta15N; 15N; glutamate; glycine; drying-rewetting; amino acids; ammonium;

    Sammanfattning : AbstractThe uptake of different nitrogen forms by understory species was studied in field and laboratory. Species of the understory in deciduous forests have previously been thought to take up and assimilate only inorganic nitrogen sources. LÄS MER

  5. 44. Environmental and Thermal Performance of District Heating Pipes

    Författare :Morgan Fröling; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; district heat distribution; cyclopentane; district heating pipe; long-term thermal performance; life cycle assessment; insulation; polyurethane foam; environmental performance; carbon dioxide; HFC-365mfc;

    Sammanfattning : In order to move towards a sustainable society we need to increase the efficiency of our use of available resources, not only in economic terms but also in ecological terms. District heating, the utilisation of centrally produced heat for space heating and domestic hot water generation, has the potential to contribute to the eco-efficient use of energy resources in the parts of the world where space heating is needed. LÄS MER

  7. 45. Biogas production from a systems analytical perspective

    Författare :Maria Berglund; Miljö- och energisystem; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Energiforskning; Energy research; indirect environmental impact; fuel-cycle emissions; environmental systems analysis; energy systems analysis; energy balance; digestate; Anaerobic digestion; biogas;

    Sammanfattning : Anaerobic digestion and the production of biogas can provide an efficient means of meeting several objectives concerning energy, environmental and waste management policy. Interest in biogas is increasing, and new facilities are being built. LÄS MER