Sökning: "hydrogen related degradation"

Visar resultat 16 - 20 av 20 avhandlingar innehållade orden hydrogen related degradation.

  1. 16. Culture-independent methods and high-throughput sequencing applied to evolutionary microbial genomics

    Författare :Anders E. Lind; Thijs JG Ettema; Purificación López-García; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Single cell genomics; metagenomics; amplicon; archaea; haloarchaea; endosymbiosis; ciliate; hydrogenosome; tree reconciliation;

    Sammanfattning : Culture-independent methods allow us to better understand the diversity of microorganisms on earth. By omitting the culturing step, we can gain access to species previously out of our reach.To better capture and understand the diversity of microorganisms, we have developed an alternative to 16S amplicon sequencing. LÄS MER

  3. 17. Tribology of carbon fiber reinforced PTFE composites in dry gas environments

    Författare :Pontus Johansson; Pär Marklund; Marcus Björling; Yijun Shi; Stephen Kukureka; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Machine Elements; Maskinelement;

    Sammanfattning : With hydrogen being one of the key pillars of decarbonization, the reliability and efficiency of hydrogen applications become increasingly important. In applications such as oil-free reciprocating hydrogen compressors and Stirling engines, the self-lubricating pistonrings and other dynamic seals are critical components in terms of efficiency, service life and proper functioning. LÄS MER

  4. 18. Recycling process water in complex sulphide ore flotation

    Författare :Fatai Kolawole Ikumapayi; Jaako Olavi Leppinen; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mineral Processing; Mineralteknik;

    Sammanfattning : An approach to environmental sustainability and improved process economy in sulphide minerals production is recycling of process water in flotation of complex sulphide ores. However process water chemistry may be a critical issue to flotation efficiency. Process water discharged from sulphide flotation circuits are usually gypsum (CaSO4. LÄS MER

  5. 19. Some aspects on the effects of dissolved wood components in kraft pulping

    Författare :Ragnar Sjödahl; Mikael E. Lindström; Hasan Jameel; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Delignification; Dissolved wood components; Black liquor; Defibration point; Cellulose and paper engineering; Cellulosa- och pappersteknik;

    Sammanfattning : During kraft cooking a significant part of the wood material, especially lignin and hemicelluloses, is degraded and dissolved in the cooking liquor, rendering a broad range of degradation products with different molecular mass and functional groups. The main part of this thesis has been devoted to clarify the role of these dissolved wood components (DWC) during kraft cooking. LÄS MER

  7. 20. Adsorption, desorption, and redox reactions at iron oxide nanoparticle surfaces

    Författare :Lelde Krumina; MEMEG; []
    Nyckelord :Ferrihydrite; Goethite; Secondary metabolites; Reductive dissolution; Catalytic oxidation; hydroxyl radicals; Fenton reaction; SOM decomposition;

    Sammanfattning : Iron oxide nanoparticles are involved in several important biogeochemical processes. The interfaces between aqueous solutions and iron oxide nanoparticle surfaces are found everywhere in nature, and the chemical and microbial processes occurring at these complex interfaces control e.g. nutrient and contaminant availability and transport. LÄS MER