Friday, November 22, 2002 4:00 p.m. Bill McKenna Acoustic Systems http://www.acousticsystems.com This tour is a class field trip for Engineering Acoustics (ME 379N, EE 363N), but it is open to the public. Acoustic Systems, located in Austin, Texas, has been designing, manufacturing, and installing acoustical products since 1971. While Acoustic Systems does offer standard products,…
Friday, November 15, 2002 4:00 p.m. Russell F.Pinkston Professor of Composition and Director of the The University of Texas at Austin Electronic Music Studios http://ems.music.utexas.edu/ While compositions involving traditional musical instruments and pre-recorded electronic sounds have been around since the 1960’s, it is only recently that the technology has advanced sufficiently to allow such sounds…
Friday, November 8, 2002 4:00 p.m. Ethan P.Honda Applied Research Laboratories The University of Texas at Austin http://www.arlut.utexas.edu Using passive sonar to localize quiet submerged acoustic sources in the presence of strong interferers has been a challenging task for much of the last century. This seminar will present a new model based spatial filter that…
Monday, November 4, 2002 4:00 p.m. Professor Jonathan Ophir Department of Radiology The University of Texas Medical School at Houston http://www.uth.tmc.edu/radiology http://www.uth.tmc.edu The mechanical attributes of soft tissues depend on their molecular building blocks (fat, collagen, etc.), on the microscopic and macroscopic structural organization of these blocks, and on the boundary conditions involved. In the…
Friday, November 1, 2002 4:00 p.m. Stephen M. Burcsak Applied Research Laboratories The University of Texas at Austin http://www.arlut.utexas.edu In 1997 the Clean Air Act was revised to include a new standard for particulate in the diameter range 0-2.5 micron-meter. Currently used industrial pollution control devices, such as electrostatic precipitators and cyclone separators, are ineffective…
Wednesday, October 23, 2002 4:00 p.m. Professor Philippe Pernod Institut d’Electronique et de Micro-electronique du Nord Ecole Centrale de Lille Villeneuve d’Acsq, France Wave phase conjugation (WPC) is a means of performing time reversal, i.e., producing a conjugate wave, which propagates backward toward the original source or scattering site as though a movie of the…
Friday, October 18, 2002 4:00 p.m. Assistant Professor Jan Moore Department of Communication Sciences and Disorders The University of Texas at Austin http://csd.utexas.edu The introduction of cochlear implants has been the most important advance in the history of rehabilitation for people with profound sensorineural hearing loss. This technology has been commercially available to children and…
Friday, October 4, 2002 4:00 p.m. Professor Craig Champlin Department of Communication Sciences and Disorders The University of Texas at Austin http://csd.utexas.edu Human communication signals vary jointly in frequency and amplitude as a function of time. Frequency analysis is accomplished primarily in the cochlea via mechanical filtering. Time analysis, on the other hand, occurs within…
Friday, September 20, 2002 4:00 p.m. Assistant Professor Stanislav Y. Emelianov Department of Biomedical Engineering The University of Texas at Austin http://www.bme.utexas.edu Ultra-short pulse (femtosecond) laser technology is evolving into a novel clinical tool capable of performing high precision surgery of transparent (i.e., cornea) or translucent (i.e., sclera) eye tissue. However, patient specific guidance and…
Friday, September 13, 2002 4:00 p.m. Dr. Kendall Waters Laboratory For Ultrasonics Washington University in Saint Louis Home The Kramers-Kronig (K-K) dispersion relations are based upon the fundamental notions of linearity and causality. The relations provide a criterion for the causal consistency of a given measurement or model of the propagation mechanisms of a medium.…
Friday, April 19, 2002 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…
Monday, April 1, 2002 4:00 p.m. Professor Paul Carson Department of Biomedical Engineering and Department of Radiology University of Michigan Home http://www.rad.med.umich.edu An acoustic beam focused in homogeneous media for interrogation or intervention will be defocused when portions of the beam travel through materials with differing speeds of sound. In echo-location imaging, such as medical…
Friday, March 22, 2002 4:00 p.m. Dr. Douglas S. Brungart Air Force Research Laboratory Wright Patterson Air Force Base http://www.wpafb.af.mil The mission of the Aural Displays and Bioacoustics branch of the Air Force Research Laboratory (AFRL/HECB) is to enhance the performance and safety of Air Force personnel by conducting research in advanced audio interfaces and…
Thursday, March 21, 2002 4:00 p.m. Professor Pierre Khuri-Yakub E.L. Ginzton Laboratory Stanford University http://www.stanford.edu/group/ginzton Stanford University With the advent of silicon micromachining, it is now possible to make capacitors with very thin gaps that sustain electric fields of the order of 109 V/ mor more. These capacitors can be made into transducers of ultrasound…
Friday, March 1, 2002 4:00 p.m. Dr. Scott Backhaus Condensed Matter and Thermal Physics Group Los Alamos National Laboratory http://www.lanl.gov/thermoacoustics Thermoacoustic engines are a class of heat engines that convert high-temperature heat into acoustic power without the use of moving parts. Recent innovations in thermoacoustics now allow the use of Stirling-like thermodynamic cycles in thermoacoustic…
Friday, February 22, 2002 4:00 p.m. William McKenna Acoustic Systems http://www.acousticsystems.com/ Source directionality is a growing concern in the qualification of precision grade anechoic measurement chambers. In such a qualification, one moves a microphone away from an omnidirectional point source and monitors the deviation from spherical spreading in free space propagation by observing fluctuations in…
Friday, February 15, 2002 4:00 p.m. Karl Martin Department of Mechanical Engineering The University of Texas at Austin http://www.me.utexas.edu In order to understand the interaction of high intensity sound with sooting flames, an acetylene burner apparatus was developed in which a gaseous jet flame was exposed to acoustic fields with sound pressure levels above 140…
Friday, February 8, 2002 4:00 p.m. Dr. Chester M. McKinney Applied Research Laboratories The University of Texas at Austin http://www.arlut.utexas.edu This seminar concludes the history of active sonars begun in the previous seminar, given one week earlier. These sonars have most or all of the following characteristics: relatively high operating frequency (35-1500 kHz), short range…
Friday, February 1, 2002 4:00 p.m. Dr. Chester M. McKinney Applied Research Laboratories The University of Texas at Austin http://www.arlut.utexas.edu This is a brief history of the development of a broad class of active sonars which generally have most or all of these characteristics: relatively high operating frequency (35-1500 kHz), short range (a few meters…
Friday, January 25, 2002 4:00 p.m. Professor Takeru Yano Department of Mechanical Science Hokkaido University, Japan http://www.hokudai.ac.jp/bureau/e/index-e.html The study of resonant gas oscillations in closed tubes is of basic importance in nonlinear acoustics. There appear various nonlinear phenomena such as shock waves, acoustic streaming, etc. In the weakly nonlinear case, the classical theory by Chester…