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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

Application of laser anemometry in acoustic measurement standards

MacGillivray, Thomas Joseph January 2002 (has links)
The absolute measurement of acoustic particle velocity using Laser Doppler Anemometry (LDA) provides the basis for a method of microphone calibration. In this thesis, after the current standardized calibration method (called reciprocity) is explained, the application of LDA to the determination of sound pressure acting on a microphone is discussed. From a measurement of the output voltage for a given sound pressure, the sensitivity of the microphone can be calculated. In LDA, there are two different techniques for detecting and analysing the Doppler signal generated by acoustic particle motion: continuous detection followed by frequency or time domain analysis, and photon correlation. After a brief discussion of the theory of both methods, their application to measurements within a standing-wave tube is investigated. Velocity measurements extracted from Doppler signals are used to derive values of sound pressure, which are compared with probe microphone measurements. The continuous detection and photon correlation LDA systems are used to measure particle velocity amplitude in a standing wave for frequencies between 660 Hz and 4kHz and velocities between 1 mms⁻¹ and 18 mms⁻¹. LDA is applied to the measurement of microphone sensitivity. The frequency response of the probe microphone is characterized relative to the response of a reference microphone. From the frequency response information, the output voltage of the probe microphone, and the LDA derived sound pressure in a standing wave the sensitivity of the reference microphone is established. Using the continuous detection system, the microphone sensitivity is measured to within ±0.1 dB of the sensitivity obtained by reciprocity calibration for frequencies between 660 Hz and 2 kHz. Using the photon correlation system, the sensitivity is measured to within ±0.2 dB for the same frequency range. Initial measurements were performed in a free field environment, using the photon correlation system, to demonstrate the potential for further development of the LDA calibration technique.
102

Jet to jet impingement in a confined space /

Tyagi, Ashok K. January 1997 (has links)
Thesis (Ph.D.) -- McMaster University, 1997. / Includes bibliographical references (p. 234-241). Also available via World Wide Web.
103

Single exposure phototesting and assessment of pigmented skin lesions : quantitative methods in terms of blood perfusion estimates /

Ilias, Michail A., January 2003 (has links) (PDF)
Diss. (sammanfattning) Linköping : Univ., 2003. / Härtill 5 uppsatser.
104

Studies on sitting pressure and buttock microcirculation : aiming at developing an alarm in the prevention of pressure ulcers in patients with spinal cord injuries /

Thorfinn, Johan, January 2006 (has links) (PDF)
Diss. (sammanfattning) Linköping : Linköpings universitet, 2006. / Härtill 5 uppsatser.
105

Untersuchung neuartiger Laser-Doppler-Verfahren zur Positions- und Formvermessung bewegter Festkörperoberflächen /

Pfister, Thorsten. January 2008 (has links)
Zugl.: Dresden, Techn. Universiẗat, Diss., 2008.
106

Three-dimensional laminar and turbulent convection in separated flow

Thiruvengadam, Magesh, January 2008 (has links) (PDF)
Thesis (Ph. D.)--Missouri University of Science and Technology, 2008. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed August 21, 2008) Includes bibliographical references.
107

Laser-Doppler-Flowmetrie bei Osteoporose : eine Untersuchung der Durchblutung des distalen Radius im Übergangsbereich von Periost zu Knochen mit Hilfe der Laser-Doppler-Flowmetrie zur Erfassung funktioneller Parameter der Mikrozirkulation /

Stracke, Siegbert. January 2007 (has links)
Zugl.: Giessen, Universiẗat, Diss., 2007.
108

Laser-Doppler-Flowmetrie bei Osteoporose eine Untersuchung der Durchblutung des distalen Radius im Übergangsbereich von Periost zu Knochen mit Hilfe der Laser-Doppler-Flowmetrie zur Erfassung funktioneller Parameter der Mikrozirkulation

Stracke, Siegbert January 1900 (has links) (PDF)
Zugl.: Giessen, Univ., Diss., 2007
109

Strömungsuntersuchungen mittels Laser-Doppler-Anemometrie in Modellen humaner Karotisbifurkationen nach Stentimplantation

Kleinschmidt, Thomas. Unknown Date (has links)
Techn. Universiẗat, Diss., 2005--München.
110

Measurement of fiber suspension flow and forming jet velocity profile by pulsed ultrasonic doppler velocimetry.

Xu, Hanjiang. January 2003 (has links)
Thesis (Ph. D.)--Institute of Paper Science and Technology, Georgia Institute of Technology, 2003.

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