Sökning: "iron cycling"

Visar resultat 11 - 15 av 41 avhandlingar innehållade orden iron cycling.

  1. 11. Iron isotopes in aquatic systems

    Författare :Sarah Conrad; Johan Ingri; Michael Bau; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Applied Geochemistry; Tillämpad geokemi;

    Sammanfattning : The cycling of iron (Fe) is a key component for understanding water quality and biogeochemical processes. It serves as mediator during biotic and abiotic processes, as electron acceptor during the degradation of organic matter, as surface for trace element and organic matter adsorption, and is necessary for primary production processes. LÄS MER

  3. 12. Brownification of freshwaters - the role of dissolved organic matter and iron

    Författare :Sara Ekström; Enhet akvatisk ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Brownification; freshwater; water color; dissolved organic matter DOM ; iron Fe ; decreasing acidification; climate change;

    Sammanfattning : The term brownification refers to the trend of increasing water color, i.e. the water becoming browner, which has been observed throughout the northern hemisphere over the last decades. Brownification has both ecological and societal implications. LÄS MER

  4. 13. Lithium iron phosphates as cathode materials in lithium batteries

    Författare :Anna S. Andersson; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry; lithium batteries; cathode materials; lithium iron phosphates; magnetic properties; Kemi; Chemistry; Kemi; Inorganic Chemistry; oorganisk kemi;

    Sammanfattning : Iron-based oxides are perhaps the only realistic cathode materials for electric and electric-hybrid vehicle applications. Two types of lithium iron phosphate, LiFePO4 andR-Li3Fe2(PO4)3, have been investigated for use within the lithium/lithium-ion polymer batteryconcept. LÄS MER

  5. 14. Creep Behavior of High Temperature Cast Materials for Exhaust Applications

    Författare :Christian Öberg; Stefan Jonsson; Baohua Zhu; John Hald; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Creep; creep behaviour; creep damage; ductile cast iron; high-alloyed austenitic cast steel; thermal cycling; tensile testing; stress relaxation; oxidation; precipitation.; Teknisk materialvetenskap; Materials Science and Engineering;

    Sammanfattning : This thesis focuses on creep of four cast materials intended for exhaust manifolds in heavy-duty truck engines. Two of the materials are ferritic ductile cast irons, SiMo51 and SiMo1000, one is an austenitic ductile cast iron, D5S, and another one is an austenitic cast steel, HK30. LÄS MER

  7. 15. Oxidation, Creep and Fatigue Synergies in Cast Materials for Exhaust Manifolds

    Författare :Shengmei Xiang; Joakim Odqvist; Baohua Zhu; Stefan Jonsson; Johan Ahlström; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fatigue; low-cycle fatigue; fatigue in an inert atmosphere; fatigue in a synthetic diesel exhaust atmosphere; corrosion-fatigue; creep-fatigue; high-temperature corrosion; high-temperature fatigue; synergistic effect; corrosion-fatigue synergy; creep-fatigue synergy; high-temperature alloys; fatigue damage; creep-fatigue damage; corrosion-fatigue damage; ductile cast iron; high-alloyed austenitic cast steel; thermal cycling; precipitation; aging.; Teknisk materialvetenskap; Materials Science and Engineering;

    Sammanfattning : The future development of engines of heavy-duty vehicles towards reduced CO2 emission will increase the exhaust gas temperature and render the exhaust atmosphere more corrosive. The current service material of exhaust gas components - a ferritic ductile cast iron called SiMo51 - will soon meet its upper-temperature limit. LÄS MER