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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.
1

Impedance measurement of local resonant sonic materials /

Cheng, Chun-kwong. January 2003 (has links)
Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references (leaves 69). Also available in electronic version. Access restricted to campus users.
2

Light weight low frequency sound focus lens /

Dai, Hin Man. January 2005 (has links)
Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2005. / Includes bibliographical references (leaves 90). Also available in electronic version.
3

Impedance measurement of resonant sonic crystals /

Ho, Kin-Ming. January 2002 (has links)
Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2002. / Includes bibliographical references (leaves 93). Also available in electronic version. Access restricted to campus users.
4

A study of the noise reduction efficiency of locally available acoustical materials /

Patana Boonyaprapa, Chalermchai Chaikittiporn, January 1983 (has links) (PDF)
Thesis (M.Sc. (Environmental Health))--Mahidol University, 1983.
5

Phononic band gap of locally resonant sonic materials with finite thickness /

Fung, Kin-Hung. January 2004 (has links)
Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004. / Includes bibliographical references (leaves 73-74). Also available in electronic version. Access restricted to campus users.
6

Acoustic characteristics of perforated dissipative and hybrid silencers

Lee, Iljae, January 2005 (has links)
Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains xvi, 195 p.; also includes graphics. Includes bibliographical references (p. 183-195). Available online via OhioLINK's ETD Center
7

Construction and characterization of a portable sound booth for onsite voice recording /

Jackson, Christophe E. January 2009 (has links) (PDF)
Thesis (M.S.)--University of Alabama at Birmingham, 2009. / Title from PDF t.p. (viewed June 30, 2010). Additional advisors: Stephen A. Watts, Paul A. Richardson, John T. Tarvin. Includes bibliographical references (p. 36-38).
8

Simultaneous structural/acoustical design of composite panels

Ruckman, Christopher E. January 1986 (has links)
Since advanced composite materials generally experience coincidence at lower frequencies than metals when used in aircraft fuselage sidewalls, they may allow more transmission of airborne noise thereby requiring heavier acoustical treatments. A sequential design approach of addressing first structural and then acoustical design does not take advantage of structural/acoustical coupling. A simultaneous approach is expected to help minimize the total sidewall mass. This thesis uses numerical optimization to examine structural/acoustical interactions and compare the sequential and simultaneous design approaches. Acoustical performance is defined in terms of the infinite panel transmission loss at frequencies surrounding the coincidence region (1600 Hz - 12800 Hz for the panels studied.) Impedance transfer theory is used to predict the acoustical properties of a flat unstiffened anisotropic panel treated with a fibrous acoustic blanket, airgap, and limp-mass septum. Structural analysis is based on a fatigue damage resistance criterion. Sequentially designed treated composite panels exibit transmission losses 15 dB - 45 dB higher (transmitted pressure is 6 - 180 times smaller) than a structurally equivalent, equal-mass aluminum panel. Depending on the type of acoustic excitation (specific incidence direction or diffuse source) and the acoustic frequency considered, the simultaneous approach alters the sequential minimum-mass panel in order to 1) improve low frequency performance by raising coincidence frequencies, 2) improve high frequency performance by lowering coincidence frequencies, or 3) make the coincidence region as narrow as possible. Since these structural alterations require that more mass be allotted to the panel and less to the treatment, they only occur for strong structural/acoustical interactions (i.e. near coincidence.) The simultaneous design approach can achieve a moderate improvement (TL increased up to 10 dB, transmitted pressure decreased by a factor or 3) over a sequential design for a particular acoustic performance index, although computation time is increased and acoustic performance may be sacrificed in other regions. / M.S.
9

Development of micro-acoustic devices with applications of viscous effects

Tan, Lin. January 2006 (has links)
Thesis (Ph. D.)--State University of New York at Binghamton, Mechanical Engineering Department, 2006. / Includes bibliographical references.
10

I. A modified <kappa-epsilon> turbulence model for high speed jets at elevated temperatures. II. Modeling and a computational study of spliced acoustic liners

Ganesan, Anand. Tam, C. K. W. January 2005 (has links)
Thesis (Ph. D.)--Florida State University, 2005. / Advisor: Dr. Christopher K. W. Tam, Florida State University, College of Arts and Sciences, Dept. of Mathematics. Title and description from dissertation home page (viewed Sept. 21, 2005). Document formatted into pages; contains xv, 118 pages. Includes bibliographical references.

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