Sökning: "Pressure wave"

Visar resultat 1 - 5 av 219 avhandlingar innehållade orden Pressure wave.

  1. 1. Ocean Wave Energy : Underwater Substation System for Wave Energy Converters

    Författare :Magnus Rahm; Mats Leijon; Ted Brekken; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wave energy; wave power; wave energy converter; direct-drive; permanent magnet linear generator; point absorber; array; farm; park; offshore; marine; substation; electrical transmission system; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Sammanfattning : This thesis deals with a system for operation of directly driven offshore wave energy converters. The work that has been carried out includes laboratory testing of a permanent magnet linear generator, wave energy converter mechanical design and offshore testing, and finally design, implementation, and offshore testing of an underwater collector substation. LÄS MER

  3. 2. 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

  4. 3. The search for reversibility of Idiopathic normal pressure hydrocephalus : Aspects on intracranial pressure measurments and CSF volume alteration

    Författare :Niklas Lenfeldt; Jan Malm; Anders Eklund; Katrine Riklund-Åhlström; John D. Pickard; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Idiopathic normal pressure hydrocephalus; intracranial pressure; subcortical ischemia; neuronal integrity; cortical activation.; infusion test; cerebrospinal fluid dynamics; outflow resistance; compliance; elastance; proton spectroscopy; functional MRI; external lumbar drainage; Neurology; Neurologi;

    Sammanfattning : BACKGROUND: Idiopathic normal pressure hydrocephalus (INPH) is still a syndrome generating more questions than answers. Today, research focuses mainly on two areas: understanding the pathophysiology – especially how the malfunctioning CSF system affects the brain parenchyma – and finding better methods to select patients benefiting from a shunt operation. LÄS MER

  5. 4. 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

  7. 5. Cerebral Hemodynamics through Intracrnial Pressure

    Författare :Sima Shahsavari; Chalmers tekniska högskola; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Intracranial dynamics; Baroreceptor reflex; Secondary brain injury; Traumatic brain injury; Collapsible tubes; Intracranial pressure; Cushing reflex; Pulse wave propagation; Cerebral autoregulation; Cerebral compliance; Mathematical modelling;

    Sammanfattning : Traumatic Brain Injury (TBI) continues to be a major problem worldwide. Today, intensive care of patients with TBI is mainly focused on preventing and treating secondary brain injuries. High pressure inside the intracranial cavity has been found to be an important feature of disturbed cerebral dynamics and secondary injuries. LÄS MER