Search for dissertations about: "ammonium"

Showing result 1 - 5 of 248 swedish dissertations containing the word ammonium.

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

    Author : Magnus Zätterström; Infektionsmedicin; []
    Keywords : 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;

    Abstract : 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. READ MORE

  4. 2. Cellulose in quaternary ammonium hydroxide solutions

    Author : Shirin Naserifar; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; quaternary ammonium hydroxides; cellulose; N; N-dimethylmorpholinium hydroxide; Triton B; NaOH; dissolution; TMAH; etherification;

    Abstract : An ever-increasing demand to shift away from fossil-based feedstock towards renewable resources has led to more use of bio-based materials. Cellulose being the most abundant biopolymer on Earth has received a considerable attention with a wide range of applications (in textile fibers, films, membranes, etc. READ MORE

  5. 3. Ammonium Feedback Control in Wastewater Treatment Plants

    Author : Linda Åmand; Bengt Carlsson; Peter Vanrolleghem; Uppsala universitet; []
    Keywords : 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;

    Abstract : 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. READ MORE

  6. 4. Asymmetric [2,3]-Sigmatropic Rearrangement of Allylic Ammonium Ylides

    Author : Jan Blid; Peter Somfai; James C. Anderson; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; asymmetric; [2; 3]-sigmatropic rearrangement; allylic amine; ammonium ylide; Lewis acid; enantioselective; boron; phosphazene base; NMR spectroscopy; DFT-calculations; Organic chemistry; Organisk kemi;

    Abstract : The thesis describes the realization of an asymmetric [2,3]-sigmatropic rearrangement of achiral allylic amines. It is divided into two parts; the first part deals with the development of a Lewis acid-mediated [2,3]-sigmatropic rearrangement and the second the asymmetric version thereof. READ MORE

  7. 5. Functional genomics of the Baltic Sea cyanobacterium Nodularia spumigena in relation to nitrogen fixation, heterocyst differentiation and toxin production

    Author : Simina Vintila; Rehab El-Shehawy; Peter Lindblad; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; cyanobacteria; Nodularia; nitrogen fixation; heterocyst; nitrogenase; ammonium; phosphate; nodularin; Baltic Sea; Plant physiology; Växtfysiologi; Plant Physiology; växtfysiologi;

    Abstract : Nodularia spumigena is a filamentous, heterocystous cyanobacterium that dominates the annual, toxic cyanobacterial blooms in the Baltic Sea. The blooms are believed to have increased in recent years, due to eutrophication by phosphate and/or nitrogen. Toxicity of these blooms is well-documented and attributed to the hepatotoxin nodularin. READ MORE