Sökning: "nitrogen iron"

Visar resultat 1 - 5 av 91 avhandlingar innehållade orden nitrogen iron.

  1. 1. Varved lake sediments and diagenetic processes

    Författare :Veronika Gälman; Ingemar Renberg; Daniel Conley; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Varved annually laminated lake sediment; diagenesis; varve appearance; iron; sulfur; chemical speciation; iron cycling; carbon; nitrogen; stabile isotopes; δ13C; δ15N; Earth sciences; Geovetenskap;

    Sammanfattning : Varved (annually laminated) sediments are of great interest for inference of past environmental conditions, as they provide dated records with high time resolution. After deposition, the sediment varves are affected by diagenesis; i.e., chemical, physical and biological changes that occur within the sediment. LÄS MER

  2. 2. Nitrogen Cycling at Cold Climate Mine Sites in Northen Sweden

    Författare :Lino Nilsson; Anders Widerlund; Anders Lundqvist; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nitrogen; Mining; Cycling; nutrients; Isotopes; Nitrogen-model; modelling; numerical-modelling; Isotope-tracing; Tracing; Isotope; geochemistry; Applied Geology; Tillämpad geologi;

    Sammanfattning : High nitrogen discharge from mining sites has been an environmental issue that has been closely studied in the recent years. The environmental effects of high nitrogen discharge are mainly eutrophication, but can also lead to changed species composition and algae blooms. LÄS MER

  3. 3. Nutrition in the second year of life. Effects of different milk compositions on dietary intakes, growth and metabolism

    Författare :Johan Svahn; Lund Pediatrik; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; protein intake; nitrogen; iron fortification; iron intake; growth; fatty acids; fat metabolism; fat intake; energy intake; dietary intake; blood lipids; cow´s milk; cholesterol; Amino acids; children; protein metabolism.; Pediatrics; Pediatri;

    Sammanfattning : In the diet for young children, whole cow´s milk is the major contributor of calories, protein and saturated fat, but it supplies little iron and polyunsaturated fat. Although several recommendations exist for the composition of formula, recommendations for the composition of milk for young children are lacking. LÄS MER

  4. 4. Molecular detection of abundance and activity of marine, symbiotic, N2-fixing cyanobacteria

    Författare :Linnéa Ström; Rachel Foster; Daniel Lundin; Katharina Pawlowski; Rehab El-Shehawy; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Diatom Diazotroph Association; Richelia; Iron; Phosphorus; Nitrogen; nifH; pstS; exbB; rnpA; växtfysiologi; Plant Physiology; marinbiologi; Marine Biology;

    Sammanfattning : Marine primary productivity in large parts of the oceans is supported by nitrogen fixers (diazotrophs). Richelia, a genus of multiple closely related species of heterocystous filamentous cyanobacterial diazotrophs, are often found in symbioses with a few genera of diatoms. Several Richelia species: R. euintracellularis, R. LÄS MER

  5. 5. Factors Related to the Formation of Gas Porosity in Grey Cast Iron: Investigation of Core Gas Evolution and Gas Concentrations in Molten Iron

    Författare :Jessica Orlenius; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; core binders; Gas porosity; hydrogen; grey iron; gas absorption; nitrogen; oxygen; gas evolution rate; green sand; mould filling; gas volume; gas solubility;

    Sammanfattning : Since gas porosity is a major casting problem, it is of greatest importance to increase the knowledge about the foundry process in order to minimise the presence of gas porosity and thereby improving the casting quality. Gas porosity is generally considered to originate from gases precipitated during solidification of iron and from entrained gas picked up by the metal during the mould filling. LÄS MER