Sökning: "Doppler"

Visar resultat 1 - 5 av 488 avhandlingar innehållade ordet Doppler.

  1. 1. A Novel Signal Model and Estimation Method for Acoustic Doppler Current Meters

    Författare :Thomas L Lagö; Teknisk akustik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Doppler Profiler; Acoustic Doppler; Gaussian Backscattering Model; ADCM; ADCP; The Symmiktos Method; Estimation; Doppler; Current; MPCA.; Technological sciences; Teknik; Electromagnetism; optics; acoustics; Elektromagnetism; optik; akustik;

    Sammanfattning : This thesis deals with the process of estimating underwater current from the backscattering signal transmitted from an ultrasonic transducer. The narrowband sinusoidal burst signal is Doppler-shifted due to the current, and this information is converted into current. LÄS MER

  3. 2. Right heart function in health and disease : a doppler echocardiography and doppler tissue imaging study

    Författare :Per Lindqvist; Elsadig E Kazzam; Anders Waldenström; Lars Åke Brodin; Umeå universitet; []
    Nyckelord :MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Medicine; Echocardiography; Doppler tissue imaging; right ventricle; cardiac catheterisation; isovolumic relaxation; isovolumic contraction; Medicin; Dermatology and venerology; clinical genetics; internal medicine; Dermatologi och venerologi; klinisk genetik; invärtesmedicin; kardiologi; Cardiology;

    Sammanfattning : Background: It is well known that performance of the right ventricle (RV) determines exercise capacity and may confer prognostic information in different cardiopulmonary diseases. To allow optimal patient management, ideal methods to assess right heart function are therefore important. LÄS MER

  4. 3. Diastolic left ventricular filling in 50-year-old male and female adults : Evaluation by Doppler echocardiography

    Författare :Toomas Kangro; Uppsala universitet; []
    Nyckelord :Medical sciences; Arterial distensibility; diastole; Doppler echocardiography; exercise; healthy persons; hypertension; LV filling; menopause; medicin; vård; MEDICINE; MEDICIN; Clinical Physiology; Klinisk fysiologi;

    Sammanfattning : Left ventricular (LV) diastolic filling abnormalities are seen in many patients with various cardiac disorders. Age is an important determinant of Doppler indices of LV diastolic filling. LÄS MER

  5. 4. Power Doppler - Principles and Potential Clinical Applications

    Författare :Anders Nilsson; PG Lindgren; Torbjörn Andersson; Uppsala universitet; []
    Nyckelord :MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Radiology; Ultrasonography; Doppler studies; Power Doppler; Volume flow; Radiologisk forskning; Radiological research; Radiologisk forskning;

    Sammanfattning : The purpose of this work was to: a) Determine whether the amount of colour in a power Doppler image is dependent on the angle between the examined vessel and the soundbeam and/or on the velocity of the flow within the vessel; b) Investigate if a dependency on flow velocity could be used for the detection of volume flow differences and c) Define clinical applications utilising the improved sensitivity to low flow of PD.In the experimental studies (study I and II) a silicon tube in a water bath was insonated, the insonation angle and the volume flow changed and the resulting images stored, transferred to a personal computer and analysed with regard to the amount of colour present in the image. LÄS MER

  7. 5. Ultrasound Doppler Based In-Line Rheometry - Development, Validation and Application

    Författare :Johan Wiklund; Livsmedelsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Teknik; Chemical technology and engineering; Kemiteknik och kemisk teknologi; Food and drink technology; Livsmedelsteknik; Technological sciences; non-Newtonian; Chemistry; Kemi; process control; In-line rheometry; Doppler; process monitoring; ultrasound;

    Sammanfattning : The trend within fluid industry is towards continuous production, leading to an increasing demand for new and improved methods that allow real-time monitoring of quality parameters and fast process control. The consistency and viscosity can be described by fluid rheology and are frequently used as quality control parameters. LÄS MER