Sökning: "Pressure waves"

Visar resultat 1 - 5 av 112 avhandlingar innehållade orden Pressure waves.

  1. 1. Interaction between Electromagnetic Waves and Localized Plasma Oscillations

    Författare :Jan-Ove Hall; Thomas Leyser; Jan Trulsen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Space and plasma physics; space physics; plasma physics; radio waves; ionospheric modification; density depleations; field-aligned irregularities; lower hybrid solitary structures; lower hybrid cavities; Z mode waves; magnetosonic waves; scattering; mode conversion; Rymd- och plasmafysik; Space physics; Rymdfysik;

    Sammanfattning : This thesis treats interaction between electromagnetic waves and localized plasma oscillations. Two specific physical systems are considered, namely artificially excited magnetic field-aligned irregularities (striations) and naturally excited lower hybrid solitary structures (LHSS). LÄS MER

  3. 2. 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

  4. 3. Adult hydrocephalus. Intracranial pressure, B-wave and clinical analysis in patients with noncommunicating and communicating hydrocephalus

    Författare :Hannes Stephensen; Göteborgs universitet; []
    Nyckelord :CSF circulation; hydrocephalus; NPH; communicating hydrocephalus; noncommunicating hydrocephalus; aqueduct stenosis; intracranial pressure; B-waves; transmantle pressure gradient; computerised data acquisition; clinical symptoms.;

    Sammanfattning : Aims of present investigations. Adult patients with clinical and radiological findings consistent with normal pressure hydrocephalus (NPH) were studied. LÄS MER

  5. 4. Loads and responses for planing craft in waves

    Författare :Anders Rosén; Dan Zenker; Brian Hayman; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Applied mechanics; planing craft; high-speed craft; waves; model tests; sull-scale trials; Teknisk mekanik; Engineering mechanics; Teknisk mekanik;

    Sammanfattning : Experimental and numerical analysis of loads and responses for planing craft in waves is considered. Extensive experiments have been performed on a planing craft, in full-scale as well as in model scale. The test set-ups and significant results are reviewed. LÄS MER

  7. 5. Measurements in Idiopathic Normal Pressure Hydrocephalus : Computerized neuropsychological test battery and intracranial pulse waves

    Författare :Anders Behrens; Jan Malm; Anders Eklund; Eva Elgh; Niklas Lenfeldt; Marianne Juhler; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Hydrocephalus; Normal Pressure; Neuropsychological tests; Neuropsychology; Reliability and validity; Software; Dementia; intracranial pressure; spinal puncture; cerebrospinal fluid pressure; pulse pressure waves; Blood flow velocity; Middle cerebral artery; Pulsatility index; Neurology; neurologi;

    Sammanfattning : Idiopathic Normal Pressure Hydrocephalus (INPH) is a condition affecting gait, cognition and continence. Radiological examination reveals enlarged ventricles of the brain. A shunt that drains CSF from the ventricles to the abdomen often improves the symptoms. LÄS MER