Search for dissertations about: "137cs"

Showing result 1 - 5 of 27 swedish dissertations containing the word 137cs.

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

    Author : Sara Almgren; Göteborgs universitet; []
    Keywords : 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;

    Abstract : 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. READ MORE

  4. 2. Environmental influence on Hg and 137Cs levels in perch (Perca fluviatilis L.) and roach (Rutilus rutilus L.) from circumneutral lakes

    Author : Lars Sonesten; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Biology; Hg; 137Cs; fish; PLS; land use; cations; humic substances; circumneutral; Biologi; Biology; Biologi; limnologi; Limnology;

    Abstract : Mercury and radioactive caesium have received immense attention in Sweden during the past decades, as common contaminants in fish. This thesis examines how the Hg and 137Cs levels in fish from 79 circumneutral lakes are affected by various environmental factors. READ MORE

  5. 3. On-line Mobile in situ Gamma Spectrometry

    Author : Thomas Hjerpe; Lund Medicinsk strålningsfysik; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; radiobiologi; Kärnfysik; Nuclear physics; radiation protection.; 137Cs; peak-to-valley method; depth distribution; orphan source search; orphan sources; emergency preparedness; mobile gamma spectrometry; nuclear accidents; Nuclear medicine; radiobiology; Nukleärmedicin;

    Abstract : Mobile in situ gamma spectrometry is an important instrument in the emergency preparedness for nuclear accidents. This work contributes through the development of strategies and analysis methods for two applications: an on-line search for gamma-emitting orphan sources and on-line estimation of the depth distribution of 137Cs. READ MORE

  6. 4. Improving accuracy of in situ gamma-ray spectrometry

    Author : Jonas Boson; Christer Samuelsson; Umeå universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; gamma-ray spectrometry; in situ measurement; HPGe detector; 137Cs; Monte Carlo; efficiency calibration; measurement uncertainty; Radiological physics; Radiofysik;

    Abstract : Gamma-ray spectrometry measurements performed on site, or “in situ”, is a widely used and powerful method that can be employed both to identify and quantify ground deposited radionuclides. The purpose of this thesis is to improve the calibration of high purity germanium (HPGe) detectors for in situ measurements, and calculate the combined uncertainty and potential systematic effects. READ MORE

  7. 5. Risk from radionuclides: a frog's perspective : Accumulation of 137Cs in a riparian wetland, radiation doses, and effects on frogs and toads after low-dose rate exposure

    Author : Karolina Stark; Nils Kautsky; Petra Wallberg; Torbjörn Nylén; Michael Gilek; Dennis Woodhead; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; dose model; mass balance budget; overbank sedimentation; amphibian; phantom; thermoluminescence chip; radiosensitivity; DNA damage; Biology; Biologi;

    Abstract : Threats from man-made radionuclides include waste issues, increasing number of power plants, underground bomb testing, nuclear weapons, and “dirty bombs”. Until recently the ionizing radiation protection system focused on protecting humans with an implied protection of biota. READ MORE