Search for dissertations about: "a.gamma"

Showing result 1 - 5 of 33 swedish dissertations containing the word a.gamma.

2. 1. Evaluation of attenuation and scatter corrections in lung and brain SPECT

   Author : Agnetha Gustafsson; Bertil Axelsson; Göteborgs universitet Avdelningen för radiofysik Department of Radiations Physics; []
   Keywords : SPECT; attenuation; scatter; detectability; Monte Carlo simulation; MEDICINE; MEDICIN;

   Abstract : Single Photon Emission Computed Tomography (SPECT) is used to image functional processes in the human body. The image process is affected by physical effects such as attenuation, scatter, spatial resolution and statistical noise. READ MORE

4. 2. Change point detection with respect to variance

   Author : Elias Erdtman; Martin Singull; Dietrich von Rosen; Nader Tajvidi; Linköpings universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES;

   Abstract : This thesis examines a simple method for detecting a change with respect to the variance in a sequence of independent normally distributed observations with a constant mean. The method filters out observations with extreme values and divides the sequence into equally large subsequences. READ MORE

5. 3. Deposition and absorption of inhaled drugs

   Author : Eva Bondesson; Malmö Klinisk fysiologi och nuklearmedicin; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; tomografi; radiologi; Klinisk fysiologi; medical instrumentation; tomography; radiology; Clinical physics; technetium-99m; radionuclide imaging; radioactive aerosol; powder inhaler; pharmacokinetics; mucociliary clearance; lung deposition; gamma scintigraphy; inhalation; deposition modelling; drug absorption; absorption enhancer; aerosol; medicinsk instrumentering; Physiology; Fysiologi;

   Abstract : Main objectives of this thesis were to evaluate a gamma scintigraphic method used to quantify drug aerosol deposition in the lung, to investigate the influence of two aerosol inhalation parameters on the distribution of inhaled dry powder within the airways, to assess pulmonary absorption kinetics and bioavailability of an inhaled hydrophilic solute in relation to site of deposition, and to assess the influence of a surface active agent (sodium taurocholate, a bile salt) on the deposition and absorption of an inhaled hydrophilic solute. Repeated planar gamma scintigraphy was found to provide the same information on total pulmonary drug deposition as an independent method that involved assessments of urinary drug recovery after blockage of gastrointestinal drug absorption when all of the critical parts of the methodological procedures were accurately and meticulously executed. READ MORE

6. 4. Interception evaporation : processes and measurement techniques

   Author : Angela Lundberg; Luleå tekniska universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Applied Geology; Tillämpad geologi;

   Abstract : In temperate regions, evaporation of water intercepted by the vegetation represents an important part of the evapotranspiration. A review of interception evaporation studies showed that knowledge about interception evaporation processes is limited and progress is hampered by technical difficulties. READ MORE

7. 5. Dark Matter searches targeting Dwarf Spheroidal Galaxies with the Fermi Large Area Telescope

   Author : Maja Garde Lindholm; Jan Conrad; Alexander L. Read; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; dark matter; Fermi-LAT; dwarf spheroidal galaxies; fysik; Physics;

   Abstract : In this thesis I present our recent work on gamma-ray searches for dark matter with the Fermi Large Area Telescope (Fermi-LAT). We have targeted dwarf spheroidal galaxies since they are very dark matter dominated systems, and we have developed a novel joint likelihood method to combine the observations of a set of targets. READ MORE