Sökning: "gamma radiation"

Visar resultat 1 - 5 av 110 avhandlingar innehållade orden gamma radiation.

  1. 1. Studies on the Gamma Radiation Environment in Sweden with Special Reference to 137Cs

    Författare :Sara Almgren; Göteborgs universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; gamma radiation; caesium; 137Cs; deposition; migration; precipitation; in situ; CDE; NWF; Chernobyl; soil sampling; field measurements; dose measurements; dose rate; TLD; natural radiation; Kriging;

    Sammanfattning : Gamma radiation in the environment today mainly originates from naturally occurring radionuclides, but anthropogenic radionuclides, such as 137Cs, contribute in some areas. In order to assess population exposure in case of fallout from nuclear weapons (NWF) or accidents, knowledge and monitoring of external gamma radiation and radionuclide concentrations in the environment is important. LÄS MER

  3. 2. Role of MTH1 and MYH proteins in genotoxic effects of radiation

    Författare :Sara Shakeri Manesh; Siamak Haghdoost; William F. Morgan; Stockholms universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MTH1; MYH; gamma radiation; UV radiation; oxidative stress; low dose rate ionizing radiation; molekylärgenetik; Molecular Genetics;

    Sammanfattning : Humans are constantly exposed to different types of radiations. It has been suggested that low dose and low dose rate of γ-radiation as well as ultra violet A (UVA) induce oxidative stress in cells that may promote mutations. LÄS MER

  4. 3. Radiation Hardness of 4H-SiC Devices and Circuits

    Författare :Sethu Saveda Suvanam; Anders Hallén; Carl-Mikael Zetterling; Ulrike Grossner; KTH; []
    Nyckelord :Silicon carbide; radiation hardness; protons; gamma radiation; bipolar junction transistors; aluminium oxide; surface recombination.; Informations- och kommunikationsteknik; Information and Communication Technology;

    Sammanfattning : Advances in space and nuclear technologies are limited by the capabilities of the conventional silicon (Si) electronics. Hence, there is a need to explore materials beyond Si with enhanced properties to operate in extreme environments. In this regards, silicon carbide (4H-SiC), a wide bandgap semiconductor, provides suitable solutions. LÄS MER

  5. 4. Photospheric emission in gamma ray bursts : Analysis and interpretation of observations made by the Fermi gamma ray space telescope

    Författare :Shabnam Iyyani; Felix Ryde; David Burrows; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; gamma ray bursts; photosphere; radiation mechanism; Theoretical Physics; teoretisk fysik;

    Sammanfattning : The large flashes of radiation that are observed in GRBs are generally believed to arise in a relativistic jetted outflow. This thesis addresses the question of how and where in the jet this radiation is produced. LÄS MER

  7. 5. Radiation induced corrosion of copper

    Författare :Åsa Björkbacka; Mats Jonsson; Christofer Leygraf; Mehran Mostafavi; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Corrosion; oxidation; copper; copper oxide; gamma radiation; radiolysis; hydrogen peroxide; hydroxyl radical; Kemi; Chemistry;

    Sammanfattning : The process of radiation induced corrosion of copper is not well understood. The most obvious situation where the knowledge of this process is crucial is in a deep repository for high level spent nuclear fuel where the fuel will be sealed inside copper canisters. LÄS MER