Sökning: "laser cooling"

Visar resultat 1 - 5 av 82 avhandlingar innehållade orden laser cooling.

  1. 1. Experimental Studies of Effusion Cooling

    Författare :Bernhard Gustafsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; laser-Doppler anemometry; infrared thermography; film cooling; flow visualization; full coverage film cooling; jet in crossflow; effusion cooling;

    Sammanfattning : The desire to increase the efficiency of jet engines, has led to an increase in the temperature in the combustion chambers and in the turbine stage. There is thus an interest in efficient cooling methods. Film cooling and effusion cooling are often used where there is a great heat load. LÄS MER

  2. 2. Formation of nanoparticles by laser-activated processes

    Författare :Lars Landström; Mats Boman; Peter Heszler; Joop Schoonman; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Inorganic chemistry; nanoparticles; laser-assisted CVD; laser ablation; emission spectroscopy; size-distribution; Oorganisk kemi; Inorganic chemistry; Oorganisk kemi; Inorganic Chemistry; oorganisk kemi;

    Sammanfattning : Due to the small dimensions, nanoparticles and materials consisting of nano-sized building blocks exhibit unique — mostly superior — properties, well differing from their bulk counterpart. Most of the novel properties of nanoparticles (and nanomaterials) are size-dependent, while the majority of the common gasphase methods used for generation of nanopowders result in different, usually wide, size-dispersions. LÄS MER

  3. 3. Laser Doppler Perfusion Monitoring and Imaging especially as regards testing for sympathetic nerve function

    Författare :Carolin Freccero; Kirurgi; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Physiology; wavelength; sympathetic vasodilatation; sympathetic vasoconstriction; sympathetic nerve function; parasympathetic nerve function; laser Doppler perfusion imaging; laser Doppler perfusion monitoring; finger skin blood flow; fibre separation; contralateral cooling; Concentration; Fysiologi; Cardiovascular system; Kardiovaskulära systemet; Diagnostik; Diagnostics;

    Sammanfattning : The operating principle of all laser Doppler methods is based on the fact that incident photons shift in wavelength when interacting with moving blood cells passing through the microvascular network. After photodetection and further signal processing, the recorded parameter can be considered an arbitrary measure of tissue blood flow, and this is referred to as ?perfusion?. LÄS MER

  4. 4. Laser processing of Silica based glass

    Författare :Patrik Holmberg; Fredrik Laurell; Valerio Pruneri; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fiber Bragg Gratings; photosensitivity; Glass; laser machining; optical fibers; fiber sensor; Physics; Fysik;

    Sammanfattning : The main topic of this thesis work is photosensitivity and photo-structuring of optical fibers and bulk glass. Although research in the field of photosensitivity in glass and optical fibers has been ongoing for more than three decades, the underlying mechanisms are still not well understood. LÄS MER

  5. 5. Laser-Directed Energy Deposition : Influence of Process Parameters and Heat-Treatments

    Författare :Suhas Sreekanth; Joel Andersson; Shrikant V. Joshi; Högskolan Väst; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Directed Energy Deposition; Alloy 718; Process Parameters; Heat Treatments; Nb- rich Phases; Production Technology; Produktionsteknik; Manufacturing and materials engineering; Produktions- och materialteknik;

    Sammanfattning : Laser-Directed Energy Deposition (L-DED), an Additive Manufacturing (AM) processused for the fabrication of parts in a layer-wise approach has displayed an immense potential over the last decade. The aerospace industry stands as the primary beneficiary due to the L-DED process capability to build near-net-shape components with minimal tooling and thereby producing minimum wastage because of reduced machining. LÄS MER