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Visar resultat 21 - 24 av 24 avhandlingar som matchar ovanstående sökkriterier.

  1. 21. Quality assurance for magnetic resonance imaging (MRI) in radiotherapy

    Författare :Mary Adjeiwaah; Tufve Nyholm; Rob HN Tijssen; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Magnetic resonance imaging; Radiotherapy; geometric distortions; patient-induced susceptibilities MR-only; radiofysik; radiation physics;

    Sammanfattning : Magnetic resonance imaging (MRI) utilizes the magnetic properties of tissues to generate image-forming signals. MRI has exquisite soft-tissue contrast and since tumors are mainly soft-tissues, it offers improved delineation of the target volume and nearby organs at risk. LÄS MER

  3. 22. Numerical Investigation of Aerodynamic Blade Excitation Mechanisms in Transonic Turbine Stages

    Författare :Björn Laumert; KTH; []
    Nyckelord :Transonic Turbines; CFD; Forced Response; Unsteady Aerodynamics;

    Sammanfattning : With the present drive in turbomachine engine developmenttowards thinner and lighter bladings, closer spaced blade rowsand higher aerodynamic loads per blade row and blade, advanceddesign criteria and accurate prediction methods for vibrationalproblems such as forced response become increasingly importantin order to be able to address and avoid fatigue failures ofthe machine early in the design process. The present worksupports both the search for applicable design criteria and thedevelopment of advanced prediction methods for forced responsein transonic turbine stages. LÄS MER

  4. 23. The temporomandibular joint : Tomopraphic and CT assesment of its bone demarcations with reference to adjacent organs

    Författare :Jan Ahlqvist; Annika Isberg; Sven-Ola Hietala; Umeå universitet; []
    Nyckelord :Temporomandibular joint; anatomy; tomography; CT; artefacts; odontologi; Odontology;

    Sammanfattning : The wall of the temporal bone separating the temporomandibular joint (TMJ) from surroundings organs, can be very thin and also have development defects. Distortion effects in the radiographic reproduction of these bone walls can result in misinterpretations when exanimating suspected pathologic changes in the region. LÄS MER

  5. 24. T-vector and T-loop morphology analysis of ventricular repolarization in ischemic heart disease

    Författare :Aigars Rubulis; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :;

    Sammanfattning : Background: Sudden cardiac death (SCD) is responsible for about half of all cardiovascular deaths in the western world. Heterogeneous ventricular repolarization (VR) is a common denominator in the genesis of malignant ventricular arrhythmias responsible for SCD and the presence of coronary artery disease (CAD) is an aggravating factor. LÄS MER