Friday, November 30, 2001 4:00 p.m. Dr. Philippe Blanc-Benon Ecole Centrale de Lyon Lyon, France The generation and scattering of sound by flow inhomogeneities such as vortices are basic problems which have received much attention in the efforts to develop methods to detect strength and location of noise sources. Recent experimental studies have demonstrated that…
Wednesday, November 28, 2001 4:00 p.m. Dr. Philippe Blanc-Benon Ecole Centrale de Lyon Lyon, France The knowledge of temperature and flow fields in the microchannels and at the edges of the stack plates becomes an increasingly important issue in the design of heat exchangers for thermoacoustic engines. On these topics we have conducted experiments in…
Friday, November 16, 2001 4:00 p.m. Dr. Nicholas P. Chotiros Applied Research Laboratories The University of Texas at Austin http://www.arlut.utexas.edu A variety of basic acoustical experiments were performed to test the linearity of sound waves in dry and water-saturated sand. The finite-amplitude and phase comparison methods were used to observe nonlinearity characteristics in sand and…
Friday, November 2, 2001 4:00 p.m. Dr. David Grant Applied Research Laboratories The University of Texas at Austin http://www.arlut.utexas.edu Light bulbs make handy acoustic impulse sources for underwater research. They are inexpensive, readily available anywhere, and simple to use, requiring no special training or heavy deployment equipment. Their acoustical properties are easily characterized in terms…
Friday, October 26, 2001 4:00 p.m. Dr. Karl B. Fisher and Dr. Rich Gramann Applied Research Laboratories The University of Texas at Austin http://www.arlut.utexas.edu Applied Research Laboratories (ARL), University of Texas at Austin , has been a leader in acoustic research since its founding as the Defense Research Laboratory immediately after World War II. ARL…
Friday, October 19, 2001 4:00 p.m. Dr. Mike Bailey Center for Industrial and Medical Ultrasound (CIMU) Applied Physics Laboratory University of Washington Shock Wave Lithotripsy (SWL), which uses focused shock waves to break up kidney stones, is a common and successful clinical procedure. However, tissue injury also results in most if not all treatments. Cavitation…
Friday, October 12, 2001 4:00 p.m. Jeff DeMoss and John Parker Dell Computer Corp. http://www.dell.com A company marketing personal computers may find it necessary to provide customers with relevant acoustical characteristics of the product. Traditional noise emission metrics, sound power and sound pressure, have normally been used. More customers are beginning to make purchasing decisions…
Friday, October 5, 2001 4:00 p.m. Richard E. Boner Boner Associates, LLC Over the past generation, the design of high school auditoria has evolved from simple, acoustically mediocre shoe-box style, to a variety of designs. Among these are narrow fan-shapes, wide fan-shapes, and experimental designs. This talk focuses on yet another design, where the school…
Friday, September 28, 2001 4:00 p.m. Dr. Tracianne B. Neilsen Applied Research Laboratories The University of Texas at Austin http://www.arlut.utexas.edu The problem of localizing and tracking a source in the shallow ocean is often complicated by uncertainty in the environmental parameters. A method is presented that uses a rotated coordinates technique [M. D. Collins and…
Friday, September 21, 2001 4:00 p.m. Dominik Hammer Department of Physics The University of Texas at Austin http://www.ph.utexas.edu Sonoluminescence is the emission of light from tiny gas bubbles in water that expand and contract under the influence of an external pressure wave. Results from experiments investigating this phenomenon are shown along with our attempts at…
Tuesday, May 1, 2001 4:00 p.m. Jack W. Reed JWR, Inc. Albuquerque, New Mexico http://www.nmia.com/~jwreed Nearly 300 FBI witness interviews reported a bang or bangs associated with this accident off Long Island in 1996. Most attention, however, was devoted to visual sightings of a described variety of streaks and flashes, which were first interpreted as…
Friday, April 20, 2001 4:00 p.m. Mark Genfan Acoustic Spaces Martindale, Texas http://www.acousticspaces.com Acoustic Spaces is involved mainly in the design and installation of recording studios, video facilities and other high-end technical facilities. We also design and provide consultation services for public theaters, home theaters, and various commercial clients. This seminar will describe the backgrounds…
Thursday, April 5, 2001 4:00 p.m. Dr. Lawrence A. Crum Center for Industrial and Medical Ultrasound Applied Physics Laboratory University of Washington http://www.apl.washington.edu/EmployeeProfiles/RPD/crum.html http://www.apl.washington.edu Medical ultrasound technology is experiencing a rebirth as methods and applications extend beyond current diagnostic imaging to include novel therapeutic and surgical uses. These applications broadly include: Tissue ablation, cautery, lipoplasty,…
Wednesday, April 4, 2001 4:00 p.m. Dr. Lawrence A. Crum Center for Industrial and Medical Ultrasound Applied Physics Laboratory University of Washington http://www.apl.washington.edu/EmployeeProfiles/RPD/crum.html http://www.apl.washington.edu/ When an acoustic wave of moderate pressure amplitude is propagated through an aqueous liquid, light emissions can be observed. This conversion of mechanical energy into electromagnetic energy is called Sonoluminescence (SL)…
Friday, March 30, 2001 4:00 p.m. Dr. Brian Storey Franklin W. Olin Cockrell School of Engineering Needham, Massachusetts http://www.olin.edu In sonochemistry, sonoluminescence, and shock-wave lithotripsy, micron-size bubbles are subjected to intense ultrasound fields. Often, bubbles in these applications experience a long, slow expansion before undergoing a collapse so violent that the contents of the bubble…
Friday, March 23, 2001 4:00 p.m. Dr. Alexander Voishvillo Cerwin-Vega, Inc. Simi Valley, California http://www.cerwin-vega.com Multitone stimulus is used in identification of weakly nonlinear systems and for assessment of nonlinearity in sound and broadcasting equipment. Spectral and statistical characteristics of multitone signals resemble those of musical signals, and the response to multitone stimulus yields more…
Friday, February 23, 2001 4:00 p.m. Lee Thompson Applied Research Laboratories The University of Texas at Austin http://www.arlut.utexas.edu A novel solution to reducing hardware requirements for 3D acoustic imaging is described. The solution is based on high-resolution imaging sonar miniaturization research currently underway at ARL:UT. The research combines techniques used in radar, optics, and time-frequency…
Friday, February 16, 2001 4:00 p.m. Dr. Timothy Walsh Institute for Computational Engineering and Sciences The University of Texas at Austin http://www.ticam.utexas.edu Within the context of the external auditory system, a benchmark that is used by acousticians and audiologists is the head-related transfer function (HRTF). The HRTF is used in understanding the localization process, deducing…
Friday, February 9, 2001 4:00 p.m. Dr. Kenneth Huang and Andrew Morrison Motorola Network Systems Ft. Worth, Texas http://www.motorola.com Initially telecommunications equipment was concealed in maintenance areas or rooftops. The miniaturization of electronics and the growth of the cellular market has permitted base station equipment to be located nearer to human observers (e.g., utility poles,…
Friday, February 2, 2001 4:00 p.m. Dr. Nicholas P. Chotiros Applied Research Laboratories The University of Texas at Austin http://www.arlut.utexas.edu An inversion of the Biot model using measured acoustic properties suggests a modification of the Biot-Stoll equations as they apply to the propagation of sound in water saturated sand. The Biot model of sound propagation…