31 |
Noise control in tubular wire stranding machinery support roll design investigations /Chan, Raymond Hung. January 1979 (has links)
Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaf 70).
|
32 |
A proposal for renovation noise control in Hong Kong /So, Kin-pong. January 1900 (has links)
Thesis (M. Sc.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 67-70).
|
33 |
Noise mitigation in urban railway operations /Tong, Soen. January 1999 (has links)
Thesis (M. Sc.)--University of Hong Kong, 1999. / Includes bibliographical references (leaves [76-80]).
|
34 |
A new methodology for sizing and performance predictions of a rotary wing ejectorMoodie, Alex Montfort. January 2008 (has links)
Thesis (Ph.D)--Aerospace Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Dr. Daniel P. Schrage; Committee Member: Dr. Lakshmi N. Sankar; Committee Member: Dr. Richard J. Gaeta; Committee Member: Dr. Stephen M. Ruffin; Committee Member: Mark H. Waters. Part of the SMARTech Electronic Thesis and Dissertation Collection.
|
35 |
Analysis of vibratory noise in the sawing of aluminum extrusionsYap, Kian Tiong. January 1981 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1981. / Typescript. Vita. Includes bibliographical references (leaves 192-196).
|
36 |
A review of policy tools for noise control in Hong Kong : the case of construction industry /Wong, Chor-kuen. January 2005 (has links)
Thesis (M.P.A.)--University of Hong Kong, 2005.
|
37 |
Low noise grain dryer designSherman, Peter James, January 1975 (has links)
Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaf 79).
|
38 |
Evaluation of management practices to minimize occupational noise exposure at Company XYZBork, Brian L. January 2005 (has links) (PDF)
Thesis, PlanB (M.S.)--University of Wisconsin--Stout, 2005. / Includes bibliographical references.
|
39 |
Acoustic propagation in nonuniform circular ducts carrying near sonic mean flows /Kelly, Jeffrey J. January 1981 (has links)
Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1981. / Vita. Abstract. Includes bibliographical references (leaves 64-69). Also available via the Internet.
|
40 |
Prediction of low-frequency sound-pressure fields in fitted rooms for active noise controlChan, Gary Ka-Yue 05 1900 (has links)
Low-frequency noise is a health concern for workers in industrial workshops; rooms of highly varying size and dimensions, usually containing obstacles (the ‘fittings’). Low-frequency noise can be generated from sources such as reciprocating or rotating machinery, or ventilation systems. As the exposure time to the noise lengthens, workers are increasingly at risk to harmful effects such as hearing loss, communication difficulty, personal discomfort, and even nausea from induced body vibrations. Passive methods of noise control, such as absorption or barriers, generally perform better at high frequencies, but are inadequate at low frequencies. A proposed solution is active noise control, which relies on destructive interference of sound waves to reduce noise levels. However, this depends on phase, and how it is affected when sound waves encounter diffracting obstacles. In addition, the geometrical configuration of the active-control system must be optimized, which can be done using a prediction model. Sound-prediction models can also estimate the decibel level of sound within a given room configuration created by a source and the attenuation provided by the control system. Therefore, it is of interest to develop a model that predicts sound propagation in fitted rooms with phase. In this thesis, sound-pressure fields were investigated in rooms containing parallelepiped obstacles at low frequencies for which the wavelength is comparable to the obstacle dimensions. The geometric theory of diffraction (GTD) was used to model edge diffraction from an obstacle and, thus, the pressure field in shadow regions. A ray-tracing prediction model was improved to consider both the amplitude and phase of sound fields, and also the effects of edge diffraction. To validate the prediction model, experiments were performed in an anechoic chamber where a source and diffracting objects were located. In collaboration with Dr Valeau at the Université de Poitiers in France, a second model based on the finite element method (FEM) was used to compare prediction results. It was found that the phase depends mostly on the direct unblocked source-to-receiver distance. The FEM and experimental results showed that occluding objects cause phase shifts. The implementation of first-order diffraction into the ray-tracing program was successful in predicting shadow zones, thus producing a better prediction of realistic sound fields in rooms with obstacles. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate
|
Page generated in 0.0626 seconds