Sökning: "shear wave"

Visar resultat 1 - 5 av 63 avhandlingar innehållade orden shear wave.

  1. 1. Ultrasound based shear wave elastography of the liver : a non-invasive method for evaluation of liver disease

    Författare :Marie Byenfeldt; Anders Elvin; Per Fransson; Odd Helge Gilja; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Anthropometric measurement; diagnostic imaging; elasticity imaging technique; blood supply; BMI; body position; fatty liver; liver disease; hepatic steatosis; liver fibrosis; liver stiffness; obesity; postural change; pressure; probe; sex characteristic; shear wave elastography; skin-to-liver capsule distance; transducer and ultrasonography; Radiography; radiografi;

    Sammanfattning : Background: Detecting liver disease at an early stage is important, given that early intervention decreases the risk of developing cirrhosis and subsequently hepatocellular cancer (HCC). The non-invasive ultrasound-based shear wave elastography (SWE) has been used clinically for a decade to assess liver stiffness. LÄS MER

  3. 2. On the Application of Surface Wave Surveys for Seismic Site Response Evaluation

    Författare :Edwin Obando; Teknisk geologi; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Surface wave; MASW; seismic site response; ground motion; seismic transfer functions; shear wave velocity; site amplification; walk-away; near-field effect; dispersion curve.;

    Sammanfattning : In sites where earthquakes occur, the use of surface wave methods represents a convenient and effective procedure for soil characterization. In particular, Multichannel Analysis of Surface Wave (MASW) has become a popular tool in many seismic micro-zoning projects. LÄS MER

  4. 3. Non-invasive imaging for improved cardiovascular diagnostics : Shear wave elastography, relative pressure estimation, and tomographic reconstruction

    Författare :David Marlevi; Matilda Larsson; Reidar Winter; Massimiliano Colarieti-Tosti; Kathryn Nightingale; KTH; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Medical imaging; Cardiovascular disease; Atherosclerosis; Hemodynamics; Ultrasound; Shear Wave Elastography SWE ; Magnetic Resonance Imaging MRI ; 4D flow MRI; Relative Pressure; Virtual Work-Energy; micro-Computed Tomography micro-CT ; Tomographic reconstruction; Pre-clinical imaging; Medicinsk avbildning; Hjärt-kärlsjukdomar; Ateroskleros; Hemodynamik; Ultraljud; Skjuvvågselastografi SWE ; Magnetresonanstomografi MRI ; 4D flödes-MRI; Tryckfall; Virtuellt flöde; mikro-Datortomografi mikro-CT ; Tomografisk rekonstruktion; Preklinisk avbildning; Medicinsk teknologi; Medical Technology;

    Sammanfattning : Throughout the last century, medical imaging has come to revolutionise the way we diagnose disease, and is today an indispensable part of virtually any clinical practice. In cardiovascular care imaging is extensively utilised, and the development of novel techniques promises refined diagnostic abilities: ultrasound elastography allows for constitutive tissue assessment, 4D flow magnetic resonance imaging (MRI) enables full-field flow mapping, and micro-Computed Tomography (CT) permits high-resolution imaging at pre-clinical level. LÄS MER

  5. 4. Identification of Viscoelastic Materials by Use of Wave Propagation Methods

    Författare :Saed Mousavi; Bengt Lundberg; Urmas Valdek; Janne Färm; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Engineering physics; Identification; Viscoelastic; Complex modulus; Complex Poisson s ratio; wave; Impact; Teknisk fysik; Engineering physics; Teknisk fysik;

    Sammanfattning : Complex moduli and Poisson’s ratio have been estimated using extensional and torsional wave experiments. The data were used for assessment of linearity and isotropy of two polymers, polymethyl methacrylate (PMMA) and polypropylene (PP). The responses of both materials were found to be close to linear and isotropic. LÄS MER

  7. 5. Attosecond Electron Wave Packet Interferences

    Författare :Thomas Remetter; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Attosecond Bound Electron Wave Packet Dynamics; Attosecond Pulse Train; High-Order Harmonics; Electron Wave Packet Interferometry; Attosecond Physics;

    Sammanfattning : Attosecond pulses offer a new route to produce temporally localized electron wave packets (EWPs) that can easily be tailored by altering the properties of the attosecond pulses. In this thesis we will present different experiments, supported by theory, where attosecond EWPs are created in presence of a strong infrared (IR) field. LÄS MER