Sökning: "narrow tube"

Visar resultat 6 - 10 av 11 avhandlingar innehållade orden narrow tube.

  1. 6. Radiation dose and x-ray beam modelling in diagnostic and interventional radiology using Monte Carlo methods

    Författare :Artur Omar; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :;

    Sammanfattning : Although medical imaging is essential for the diagnosis and treatment of a wide range of medical conditions, the radiation dose from x-ray examinations is one of the largest contributors to the exposure of the world’s population. It is therefore the responsibility of healthcare professionals to ensure that examinations are justified (a net benefit) and optimized (as low dose as reasonably achievable). LÄS MER

  3. 7. The role of benthic macrofauna in nitrogen cycling in eutrophic lake sediment

    Författare :Jonas Martin Svensson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; nitrogen retention; nitrous oxide; oligochaetes; chironomids; mineralisation; nitrification; denitrification; eutrophic; sediment; lake; Macrofauna; nitrogen cycling; fish reduction.; Ecology; Ekologi;

    Sammanfattning : This thesis concerns the role of sediment-living macrobenthos in the cycling of nitrogen species and nitrogen transformation in eutrophic freshwater sediments. In my thesis I have, employing 15N-isotope techniques in laboratory experiments, shown the importance of infaunal chironomid larvae and oligochaetes on denitrification in eutrophic lake sediments. LÄS MER

  4. 8. Is water a crucial factor in the oxidation of FeCrAl alloys?

    Författare :Helena Josefsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; alpha-Al203; oxidation kinetics; high temperatur corrosion; reactive elements; FeCrAl; vater vapour; transient alumina;

    Sammanfattning : FeCrAl alloys are much used at high temperatures because the formation of a dense and slow-growing alumina scale provides resistance towards oxidation and high temperature corrosion. While the FeCrAl alloys are primarily intended for temperatures above 950ºC, they are sometimes used at lower temperature, for example as supports in automotive catalysts. LÄS MER

  5. 9. Axon Guidance and Morphogenesis of the C. elegans Pharynx

    Författare :Manish Rauthan; Chalmers tekniska högskola; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; pharynx; M2; C. elegans; extra-cellular matrix ECM ; hex; Krüppel; pha-2; isthmus; NSM; pharyngeal neurons.; cytoskeleton; mnm-2;

    Sammanfattning : The C. elegans pharynx is a single cell thick muscular tube that undergoes morphogenesis to attain it mature structure from a ball of 80 undifferentiated cells. This thesis is about understanding the mechanisms and the genetic pathways underlying the process of pharyngeogenesis. LÄS MER

  7. 10. Experimental Heat Transfer, pressure drop, and Flow Visualization of R-134a in Vertical Mini/Micro Tubes

    Författare :Wahib Owhaib; Björn Palm; Tassos Karayiannis; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Minichannel; microchannel; heat transfer; pressure drop; single-phase; two-phase; flow boiling; flow visualization; dry out; bubble behavior; flow pattern.; Mechanical energy engineering; Mekanisk energiteknik;

    Sammanfattning : For the application of minichannel heat exchangers, it is necessary to have accurate design tools for predicting heat transfer and pressure drop. Until recently, this type of heat exchangers was not well studied, and in the scientific literature there were large discrepancies between results reported by different investigators. LÄS MER