Friday, February 25, 2000 4:00 p.m. Dr. Nicholas P. Chotiros Applied Research Laboratories The University of Texas at Austin http://www.arlut.utexas.edu The participation of ARLUT in the sediment acoustics experiment (SAX99) is directed towards determining the underlying physical processes in the penetration of sound into sandy ocean sediments, particularly at shallow grazing angles, and the scattering…
Friday, February 18, 2000 4:00 p.m. Dr. Kevin Warner and Dr. Elan Yogeswaren Daniel Measurement and Control, Inc. Houston, Texas http://www.danielind.com Use of ultrasound transit time to measure flow was first proposed in the late 1920s, but not until the 1960s did an operational device become available. Work initiated by British Gas in the 1980s…
Friday, February 11, 2000 4:00 p.m. Guillermo Aldana Department of Electrical and Computer Engineering The University of Texas at Austin http://www.ece.utexas.edu Real time data collection in down-hole environments has long been a goal of the drilling and oil industries. Information such as pressure, deviation from vertical, and temperature near the drill bit is used for…
Friday, February 4, 2000 4:00 p.m. Dr. Leslie Bowen Materials Systems, Inc. Littleton, Massachusetts http://www.matsysinc.com 1-3 piezocomposite is a relatively new entry into the piezoelectric materials portfolio of acoustic transducer designers. Originally conceived in the 1970s at Penn State’s Materials Research Laboratory, the material was of limited academic interest until the early 1990s when MSI…
Thursday, January 27, 2000 4:00 p.m. Michael Fripp Massachusetts Institute of Technology Cambridge, Massachusetts http://www.mit.edu Reconfigurable arrays of sensors and actuators can provide robust broadband feedback control with high performance and limited modeling. The weighted summation of the sensor signals identifies the modes that are important to performance and rejects the remaining modes, thus reducing…
Friday, December 3, 1999 4:00 p.m. Professor David Peterson Department of Mathematics University of Central Arkansas Conway, Arkansas http://www.uca.edu/divisions/academic/math http://www.uca.edu For thousands of years Indian cultures in the Western hemisphere have produced whistling vessels and musical instruments, ocarinas, from clay. Ocarinas are found in wide array of morphological forms – vegetables, animals, demons, etc. –…
Tuesday, November 23, 1999 4:00 p.m. Ronald E. Kumon Department of Physics The University of Texas at Austin http://www.ph.utexas.edu Both the linear and nonlinear properties of surface waves in crystals are significantly different from those in isotropic media. Recently developed model equations are employed to perform theoretical and numerical studies of nonlinear surface acoustic waves…
Friday, November 19, 1999 4:00 p.m. Washington De Lima Department of Mechanical Engineering The University of Texas at Austin http://www.me.utexas.edu Harmonic generation by Rayleigh–Lamb waves of finite amplitude in homogeneous, isotropic, stress-free elastic plates is investigated theoretically. A bifrequency primary wave field is considered, in which the two waves propagate in single yet arbitrary Rayleigh–Lamb…
Friday, November 12, 1999 4:00 p.m. Dr. Tom Kite Audio Precision Beaverton, Oregon http://audioprecision.com This talk will describe techniques used to measure performance parameters of both analog and digital audio equipment. Particular attention will be given to methods that are also appropriate to acoustic measurements, such as the use of maximum-length sequences (MLS) for pseudo-anechoic…
Friday, October 22, 1999 4:00 p.m. Mike Stoeckle Ford Motor Company http://www.ford.com Acoustical considerations play an important role in the design and development of an automobile. The purpose of this discussion is to inform students interested in acoustics of practical applications and the design process in the automotive industry. Emphasis will be on acoustical aspects…
Friday, October 15, 1999 4:00 p.m. Dr. Jean-Pierre Masson and Dr. Kai Hsu Schlumberger Sugarland Product Center Sugarland, Texas http://www.schlumberger.com We present an overview of acoustical measurements while drilling, ranging from low frequency seismic to ultrasonic pulse-echo measurements. The main topic is the development of an acoustical logging-while-drilling (LWD) tool in the kilohertz range. This…
Friday, October 8, 1999 4:00 p.m. Jeff DeMoss Center for Transportation Research The University of Texas at Austin http://www.utexas.edu/research/ctr Pavement type and surface configuration are known to have a significant effect on traffic noise. Studies of different roadway surfaces have shown that more-porous pavement designs perform better acoustically. However, pavements are currently designed for durability…
Friday, October 1, 1999 4:00 p.m. Professor Timothy Fowler Department of Civil Engineering The University of Texas at Austin http://www.ce.utexas.edu Acoustic emission serves an important function in the process industries. It is a global nondestructive examination technique which provides a measure of the structural severity of a defect. As such, it is complementary to other…
Friday, September 24, 1999 4:00 p.m. David A. Nelson Nelson Acoustical Engineering, Inc. A “Reduced-Noise Gas Flow Design Guide” has recently been developed for NASA’s John H.Glenn Research Center (GRC) at Lewis Field, Ohio. The purpose of the Guide is to allow GRC engineers and designers to address hearing conservation and community noise issues at…
Friday, September 17, 1999 4:00 p.m. Dr. Robert Rogers Applied Research Laboratories The University of Texas at Austin This talk is an overview of the efforts at ARL:UT to develop and improve the plasma sound source, also known as a spark source. Spark sources, or plasma sources, have been used for the creation of impulsive…
Thursday, June 17, 1999 4:00 p.m. Dr. Qing-Ming Wang Lexmark International, Inc. Lexington, Kentucky http://www.lexmark.com The development of piezoelectric Pb(Ti 0.52 Zr 0.48 )O 3(PZT) thin films toward device miniaturization for microelectromechanical system (MEMS) applications depends largely on the processing capability of PZT film on silicon substrate, since the combination of PZT thin film with…
Monday, May 17, 1999 4:00 p.m. Dr. Yichi Lu Southwest Texas Research Institute San Antonio, Texas The magnetostrictive sensor is a non-contact, nondestructive inspection technology that is suitable for inspecting ferromagnetic components. Progress has been made in recent years in order to use magnetostrictive sensors for long range pipeline corrosion inspection, suspension bridge cable inspection,…
Friday, April 23, 1999 4:00 p.m. Dr. Michael H. Krane Rutgers University Camden, New Jersey http://www.rutgers.edu Progress in speech synthesis is limited in part due to a lack of information concerning the fundamental physics underlying the production of speech sounds. The goal of this work is to apply knowledge from the fields of aeroacoustics and…
Friday, April 9, 1999 4:00 p.m. Joseph B. Gaalaas Department of Mechanical Engineering The University of Texas at Austin http://www.me.utexas.edu An algorithm has been designed that allows one to calculate the individual element weights, as a function of frequency, required to achieve specified values of sidelobe level and half-power beamwidth. The arrays considered have linear…
Monday, March 29, 1999 4:00 p.m. Dr. Bart Lipkens Macrosonix Richmond, Virginia http://www.macrosonix.com A new technology called Resonant Macrosonic Synthesis (RMS) has been developed. RMS allows the creation of high amplitude shock-free standing waves in oscillating closed cavities that are driven by a linear motor. Measurements in cavities designed with RMS show standing wave overpressures…