Sökning: "Iron formations"

Visar resultat 1 - 5 av 19 avhandlingar innehållade orden Iron formations.

  1. 1. Origin of Goe Range iron formations and iron ores with emphasis on genetic implications of phosphorous and alumina distribution

    Författare :John W. Berge; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : .... LÄS MER

  3. 2. Phosphate and Arsenic Cycling under Experimental Early Proterozoic Marine Conditions

    Författare :Christoffer Hemmingsson; Iain Pitcairn; Ernest Chi Fru; Per Andersson; Christophe Dupraz; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; DIP; Early Proterozoic; coprecipitation; adsorption; Iron formations; BIF; geokemi; Geochemistry;

    Sammanfattning : Nutrient dynamics in the Archean-Paleoproterozoic oceans strongly influenced primary productivity and the rise of atmospheric O2. Reconstructing the cycling of key nutrients such as dissolved inorganic phosphate (DIP) at this time is important for our understanding of the timing, rate and extent of atmospheric oxygenation at this time. LÄS MER

  4. 3. Some aspects of convection as well as graphite and carbide formations during casting

    Författare :Fareed Ashraf Khan; Michael Vynnycky; Pär Jönsson; Bo Rogberg; Hasse Fredriksson; Jessica Elfsberg; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; carbides; heat treatment; cast iron; ball bearing steel; casting; cooling rate; structure analysis; nodule distribution; melt stirring; nuclei; karbider; värmebehanding; gjutjärn; kullagerstål; gjutning; kylningshastighet; strukturanalys; nodulefördelning; smältrörelse; kärnor.; Metallurgical process science; Metallurgisk processvetenskap;

    Sammanfattning : It is an established fact that segregation during casting affects the physical properties of carbon-based ferro alloys; this motivates the study of the segregation behaviour of carbon and carbide-forming solute elements. In this context, this thesis investigates two different situations: the effects of cooling rate and turbulence on the precipitation behaviour of the graphite nodules in nodular cast iron; the nature of carbide precipitation in a bearing steel grade and the effects of subsequent soaking on these carbides. LÄS MER

  5. 4. Combined Iron-Manganese Oxides for Chemical-Looping with Oxygen Uncoupling

    Författare :Golnar Azimi; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Iron-manganese oxide.; Keywords: CO2 capture; Chemical-looping with oxygen uncoupling; Chemical-looping combustion;

    Sammanfattning : AbstractThe most important factor affecting global warming is the increased concentrations of greenhouse gases in the atmosphere. Carbon dioxide is considered as the most important anthropogenic greenhouse gas. LÄS MER

  7. 5. Arene Iron Complexes in Organic Synthesis. New Routes to Benzophenones, Diaryl Selenides, Xanthones and Thioxanthones

    Författare :J Peter Storm; Centrum för analys och syntes; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Directed remote Metalation; nucleophilic aromatic addition; nucleophilic aromatic substitution; Arene-iron complexes; balanol; Organic chemistry; Organisk kemi;

    Sammanfattning : A multi-step route to unsymmetrically substituted benzophenones based on cationic hapto6-arene-hapto5-cyclopentadienyl iron complexes has been developed. The key features are nucleophilic aromatic substitution reactions performed on hapto6-2-chlorocarbomethoxybenzene-hapto5-cyclopentadienyl iron hexafluorophosphate with phenoxides, followed by intramolecular Friedel-Crafts ring-closure. LÄS MER