Sökning: "ultraviolet"

Visar resultat 21 - 25 av 303 avhandlingar innehållade ordet ultraviolet.

  1. 21. Skin phototesting using a divergent ultraviolet B beam : development and evaluation on a normal material

    Författare :Michail Ilias; Linköpings universitet; []
    Nyckelord :MEDICINE; MEDICIN;

    Sammanfattning : The phototesting method proposed provokes the skin by means of a divergent UVB beam. The beam divergence is induced by an optical plano-concave !ens placed at the opening of the light guide which directs the light from the UV lamp to the skin. LÄS MER

  3. 22. Towards ultrafast imaging with extreme ultraviolet light sources

    Författare :Jörg Schwenke; Lunds universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Photo emission electron microscopy; Focusing of X-ray radiation; Digital holography; High-order harmonic generation; Free-electron laser seeding; Secondary electron cascades; Fysicumarkivet A:2012:Schwenke;

    Sammanfattning : This thesis reports experimental studies performed with two advanced coherent XUV sources with ultrashort pulse duration, high-order harmonic generation and seeded-free electron laser. High-order harmonic generation (HHG) is the generation of overtones of a fundamental laser pulse in a medium, e.g. noble gases. LÄS MER

  4. 23. Development and repair of cataract induced by ultraviolet radiation

    Författare :Ralph Michael; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :ultraviolet radiation; cataract; forward light scattering; lens ultrastructure; refractive index; dose-response; repeated exposure; apoptosis; in vivo; rat;

    Sammanfattning : Background: Several epidemiological investigations show a correlation between cataract development and the dose of ultraviolet radiation (UVR) received. It is experimentally well established that exposure of animal eyes to UVR induces cataract. Most cataracts develop as a gradual increase in lens opacity. LÄS MER

  5. 24. Safety limit estimation for cataract induced by ultraviolet radiation

    Författare :Xiuqin Dong; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :Ultraviolet radiation UVR ; Sprague-Dawley rat; cataract; light scattering; doseresponse function; maximum acceptable dose MAD ; maximum tolerable dose MTD ; in vivo; in vitro; age.;

    Sammanfattning : Background: Ultraviolet radiation (UVR) is considered one of the major risk factors for agerelated cataract. UVR-induced cataract follows a continuous dose-response function. LÄS MER

  7. 25. Effects of enhanced ultraviolet-B radiation on subarctic ecosystems

    Författare :Carola Gehrke; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; pigmentation; photosynthesis; dark respiration; shoot morphology; shoot growth; phanerogams ; species composition cryptogams; productivity; decomposition; dwarf shrubs; bryophytes; peatland ecosystem; heath ecosystem; UV-B; ozone depletion; Plant ecology; Växtekologi;

    Sammanfattning : Biologically harmful ultraviolet-B radiation (UV-B, 280-320 nm) is increasing at the Earth´s surface owing to stratospheric ozone depletion. This is of global concern due to potential impacts of enhanced UV-B radiation on the biosphere. LÄS MER