Sökning: "Purge"

Visar resultat 6 - 10 av 13 avhandlingar innehållade ordet Purge.

  1. 6. Electrode degradation in proton exchange membrane fuel cells

    Författare :Alejandro Oyarce; Göran Lindbergh; Carina Lagergren; Steven Holdcroft; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; PEMFC; PEFC; Porous electrodes; Carbon corrosion; Carbon nanotubes; Carbon fibers; Polyhedral carbon nanofoams; Phosphonated hydrocarbon ionomer; Mass-transport losses; Electrode morphology; Electrode collapse; Start-up and shut-down; System strategies; Stainless steel; Bi-polar plates; In-situ contact resistance.;

    Sammanfattning : The topic of this thesis is the degradation of fuel cell electrodes in proton exchange membrane fuel cells (PEMFCs). In particular, the degradation associated with localized fuel starvation, which is often encountered during start-ups and shut-downs (SUs/SDs) of PEMFCs. At SU/SD, O2 and H2 usually coexist in the anode compartment. LÄS MER

  3. 7. On the Effects of Blood Parasites in Wild Birds

    Författare :Peter Halvarsson; Jacob Höglund; Staffan Bensch; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Atoxoplasma; avian malaria; coccidia; Gallinago media; Haemoproteus; Leucocytozoon; parasite prevalence; Passer montanus; Plasmodium; recapture mod-els; survival; Biologi med inriktning mot populationsbiologi; Biology with specialization in Population Biology;

    Sammanfattning : Coccidian and haemoatozoan parasites are commonly occurring endo-parasites in wild birds and prevalence can vary among species and populations. In addition to prevalence studies, parasites are often used to investigate effects on life history traits. LÄS MER

  4. 8. Model-based Analysis and Design of Atomic Layer Deposition Processes

    Författare :Anders Holmqvist; Avdelningen för kemiteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Atomic layer deposition; Heterogeneous reaction kinetics; Limit-cycle dynamics; Parameter estimation; Multi-objective optimization; Dynamic optimization; Scale-up analysis;

    Sammanfattning : Atomic layer deposition (ALD) is a thin-film manufacturing process in which the growth surface is exposed to non-overlapping alternating injections of gas-phase chemical precursor species separated by intermediate purge periods to prevent gas-phase reactions. ALD is characterized by sequential self-terminating heterogeneous reactions between highly reactive gas-phase precursor species and surface-bound species which, when allowed sufficient conditions to reach saturation, results in highly conformal films, on both planar and topographically complex structures. LÄS MER

  5. 9. Evolutionary consequences of sex-specific selection

    Författare :Josefine Stångberg; Elisabeth Bolund; Elina Immonen; Jennifer Perry; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Caenorhabditis remanei; Callosobruchus maculatus; sex-specific selection; sexual selection; experimental evolution; intralocus sexual conflict; life history evolution; sexual dimorphism; trade-offs; Quantitative genetics;

    Sammanfattning : Sex-specific selection is widespread, evident by the evolution of sexual dimorphism in many traits in sexually reproducing taxa. The reason why the sexes may experience selection that differs in direction or magnitude is often linked to the reproductive strategies associated with the sex-specific reproductive physiology. LÄS MER

  7. 10. Modulators of Vibrio cholerae predator interaction and virulence

    Författare :Barbro Lindmark; Sun Nyunt Wai; Kristian Riesbeck; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Vibrio cholerae; Caenorhabditis elegans; PrtV; outer membrane vesicles; non-O1 non-O139; serum resistance; Molecular biology; Molekylärbiologi; molekylärbiologi; Molecular Biology;

    Sammanfattning : Vibrio cholerae, the causal agent of cholera typically encodes two critical virulence factors: cholera toxin (CT), which is primarily responsible for the diarrhoeal purge, and toxin-co-regulated pilus (TCP), an essential colonisation factor. Nontoxigenic strains expressing TCP can efficiently acquire the CT gene through lysogenic conversion with CTXΦ, a filamentous phage that encodes CT and uses TCP as a receptor. LÄS MER