Avancerad sökning

Visar resultat 1 - 5 av 59 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. 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

  3. 2. Phytostabilization of mine tailings covered with fly ash and sewage sludge

    Författare :Clara Neuschütz; Maria Greger; Lena Kautsky; Anthony R. Dexter; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ammonium; biosolids; cadmium; copper; energy crop; metal and nutrient leakage; nitrate; phosphate; phytoremediation; plant stress response; root exudates; zinc; Plant physiology; Växtfysiologi; växtfysiologi; Plant Physiology;

    Sammanfattning : Establishing plant communities is essential for the restoration of contaminated land. As potential cover materials, fly ash and sewage sludge can prevent formation of acid mine drainage from sulfidic mine waste. LÄS MER

  4. 3. Picophytoplankton seasonal dynamics in the Baltic Sea

    Författare :Javier Alegria Zufía; Hanna Farnelid; Catherine Legrand; Nathan Ahlgren; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; picophytoplankton; Synechococcus; picoeukaryote; phycoerythrin; phycocyanin; ammonium; nitrate; 16S rDNA; flow cytometry; grazing; viral lysis; seasonality; Akvatisk ekologi; Aquatic Ecology;

    Sammanfattning : Picophytoplankton (15°C there was a preference for ammonium over nitrate. Clade A/B dominated the SYN community, except during summer at the coastal station when low nitrate and warm temperatures promoted S5.2 dominance. Grazing was observed to control SYN and PPE abundances and had an effect on the SYN community structure. LÄS MER

  5. 4. Denitrification as an adaptive trait in soil and groundwater bacteria

    Författare :Christer Bergwall; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; microcosm; forest soil; aquifer; groundwater; reductase; nitrous oxide; nitric oxide; nitrite; nitrate; selection; adaptation; bacteria; nitrification; Denitrification; dissimilatory nitrate reduction to ammonium; fertiliser; 15NO3-; 15NH4 ; Ecology; Ekologi;

    Sammanfattning : The focus of the thesis is on selection and adaptation processes in bacteria with emphasis on denitrifying bacteria in groundwater. Other nitrogen transformation processes such as dissimilatory nitrate reduction to ammonium (nitrate ammonification) and nitrification of forest soil bacteria are briefly discussed. LÄS MER

  7. 5. Ammonium Feedback Control in Wastewater Treatment Plants

    Författare :Linda Åmand; Bengt Carlsson; Peter Vanrolleghem; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; aeration control; ammonium feedback control; biological nitrogen removal; full-scale experiments; gain scheduling control; PI control; process control; repetitive control; wastewater treatment; Elektroteknik med inriktning mot reglerteknik; Electrical Engineering with specialization in Automatic Control;

    Sammanfattning : The aeration process is often the single largest consumer of electricity in a wastewater treatment plant. Aeration in biological reactors provides microorganisms with oxygen which is required to convert ammonium to nitrate. Ammonium is toxic for aqueous ecosystems and contributes to eutrophication. LÄS MER