Sökning: "partial volume effect"

Visar resultat 1 - 5 av 47 avhandlingar innehållade orden partial volume effect.

  1. 1. Error reduction strategies for quantitative PET with focus on hybrid PET/MRI

    Författare :Elin Wallstén; Anne Larsson; Jan Axelsson; Katrine Riklund; Ronald Boellaard; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Positron emission tomography; PET; PET MR; PET MRI; medical imaging; partial-volume effect; attenuation correction; radiofysik; radiation physics;

    Sammanfattning : Positron Emission Tomography (PET) is an important tool for detection, staging and follow-up in a wide range of diseases, including cancer and neurological disorders. As a functional imaging tool, PET can visualize biological processes, where positron emitting radioactive isotopes are connected to molecules with different functions in the body. LÄS MER

  3. 2. Methodological improvements in quantitative MRI : Perfusion estimation and partial volume considerations

    Författare :André Ahlgren; Lund Medicinsk strålningsfysik; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES;

    Sammanfattning : The magnetic resonance imaging (MRI) scanner is a remarkable medical imaging device, capable of producing detailed images of the inside of the body. In addition to imaging internal tissue structures, the scanner can also be used to measure various properties of the tissue. LÄS MER

  4. 3. Small Molecule Diffusion in Spherulitic Polyethylene : Experimental Results and Simulations

    Författare :Alessandro Mattozzi; Ulf W. Gedde; Alan H. Windle; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; diffusion; polyethylene; poly ethylene-co-octene ; free volume; morphology; intermediate phase; spherulite; Monte Carlo simulation; Polymer chemistry; Polymerkemi;

    Sammanfattning : The diffusion of small-molecule penetrants in polyethylene is hindered by impenetrable crystals and by the segmental constraints imposed by the crystals on the penetrable phase. Liquid and vapour n-hexane sorption/desorption measurements were performed on metallocene catalyzed homogenous poly(ethylene-co-octene)s. LÄS MER

  5. 4. Characterising Resistance to Electrical Treeing in New XLPE-Based Materials for High-Voltage Cables

    Författare :Anette Johansson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; electrical treeing; partial discharge; cross-linked polyethylene; voltage stabiliser; degradation; power cables;

    Sammanfattning : This work looks into electrical treeing in cross-linked polyethylene-based materials (XLPE), where the ability to resist tree development is considered as an indicator of improved applicability for insulation in high voltage power cables. The thesis presents results of a twin PhD project involving joint work of two students. LÄS MER

  7. 5. Materials for Hydrogen storage and synthesis of new materials by hydrogenation

    Författare :Serhiy Luzan; Alexandr Talyzin; Yaroslav Filinchuk; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fullerene C60; MOFs; CNTs; SWCNTs; PAHs; peapods; hydrogen; hydrogen storage; hydrogenation; adsorption; surface area; pore volume; spillover; nanoribbons; fragmentation; fysikalisk kemi; Physical Chemistry; fysik; Physics;

    Sammanfattning : The search for new materials for hydrogen storage is important for the development of future hydrogen energy applications. In this Thesis, it is shown that new materials with interesting properties can be synthesized by the reaction of hydrogen with various nanocarbon precursors. The thesis consists of two parts. LÄS MER