Friday, February 13, 2015 4:00pm in ETC 4.150 Dr. Mark Lai The Institute for Computational Engineering and Sciences The University of Texas at Austin Consider a sensing system using a large number of N microphones placed in multiple dimensions to monitor an acoustic field. Using all the microphones at once is impractical because of the…
Friday, February 6, 2015 4:00pm in ETC 4.150 Dr. Roger Waxler National Center for Physical Acoustics The University of Mississippi http://www.olemiss.edu/depts/physics_and_astronomy/faculty/waxler.html It is well known that both acoustic and seismic noise spectra show an increased band of spatially coherent noise around 0.2 Hz, the so-called microbarom and microseism signals. It has been appreciated for over a half…
Friday, January 30, 2015 4:00pm in ETC 4.150 Dr. Likun Zhang Center for Nonlinear Dynamics The University of Texas at Austin http://chaos.utexas.edu/people/post-docs/likun-zhang The speed of sound in the ocean varies with temperature, salinity, and pressure over the entire ocean depth. This variation results in a sound speed profile that supports a sound channel for transmitting…
Friday, December 5, 2014 4:00 p.m. ETC 4.150 Anthony L. Bonomo Applied Research Laboratories The University of Texas at Austin http://www.arlut.utexas.edu The acoustic behavior of sediments has been studied extensively. The earliest models were based on the assumption that sediments behaved like fluids. Since sediments generally can support shear stresses, the assumptions made when using…
Wednesday, December 3, 2014 4:00 p.m. ARL A009 Jason A. Kulpe George W. Woodruff School of Mechanical Engineering Georgia Institute of Technology http://www.me.gatech.edu In the open ocean, acoustic scattering of SONAR signals in the 1-10 kHz frequency range is dominated by large fish schools, where multiple scattering effects between the air-filled swim-bladders of the fishes…
Friday, November 21, 2014 4:00 p.m. ETC 4.150 Professor Neal A. Hall Department of Electrical and Computer Engineering The University of Texas at Austin https://sites.google.com/site/utacousticmems The parasitoid fly Ormia Ochracea has the remarkable ability to locate crickets using audible sound. This ability is, in fact, remarkable as the fly’s hearing mechanism spans only 1.5 mm,…
Friday, November 14, 2014 4:00 p.m. ETC 4.150 Dr. Drew Loney George W. Woodruff School of Mechanical Engineering Georgia Institute of Technology http://www.me.gatech.edu The controlled atomization of high viscosity liquids to produce individual droplets of uniform diameter remains an ongoing technological challenge. Traditional atomization techniques for the production of single droplets—inkjet printers—do not extend to…
Friday, November 7, 2014 4:00 p.m. ETC 4.150 Dr. Douglas F. Winker ETS-Lindgren Cedar Park, Texas http://www.ets-lindgren.com ETS-Lindgren manufactures acoustic test chambers for a wide variety of clients and applications. This presentation will discuss case studies of test and measurement solutions. The design and construction of ETS-Lindgren’s acoustic lab facility in Cedar Park, Texas will…
Monday, November 3, 2014 1:30 p.m. ARL Auditorium Dr. Boris Gurevich Curtin University and CSIRO Perth, Australia http://www.csiro.au Understanding and modelling of attenuation of elastic waves in fluid-saturated rocks is important for a range of geophysical technologies that utilise seismic, acoustic or ultrasonic amplitudes. A major cause of elastic wave attenuation is viscous dissipation due…
Friday, October 17, 2014 4:00 p.m. ETC 2.136 Dr. F. Michael Pestorius Applied Research Laboratories The University of Texas at Austin http://www.arlut.utexas.edu Modern submarines use sonar almost exclusively for ship navigation, obstacle avoidance, contact detection and warfare missions. Rudimentary sonars were first developed in World War I and they reached fairly high levels of sophistication…
Monday, October 13, 2014 3:00 p.m. ECJ 1.202 Dr. Michael R. Haberman Applied Research Laboratories and Department of Mechanical Engineering The University of Texas at Austin http://www.arlut.utexas.edu http://www.me.utexas.edu Acoustic metamaterials (AMM) are material systems whose overall performance originates from engineered sub-wavelength structure rather than the inherent material properties of their constituents. This relatively new topic…
Friday, October 3, 2014 4:00 p.m. ETC 4.150 Sumedh M. Joshi Center for Applied Mathematics Cornell University http://www.cam.cornell.edu Sound propagating in a moving fluid will be advected, refracted, and Doppler shifted by the patterns in the moving flow. For example, a pulse of sound impinging on an inviscid shear layer is advected in the direction…
Friday, September 26, 2014 4:00 p.m. ETC 4.150 Dr. Jason D. Sagers Applied Research Laboratories The University of Texas at Austin http://www.arlut.utexas.edu Addressed is the statistical inference of the sound-speed depth profile of a thick soft seabed from broadband sound propagation data recorded in the Gulf of Oman Basin in 1977. The acoustic data are…
Friday, September 19, 2014 4:00 p.m. ETC 4.150 Dr. James M. Gelb Applied Research Laboratories The University of Texas at Austin http://www.arlut.utexas.edu While seemingly disparate, the musical scales used throughout the world are in fact surprisingly universal. This talk touches on all aspects of this universality, from the perspectives of the acoustical properties of instruments…
Monday, September 15, 2014 1:00 p.m. RLM 11.204 Professor Joseph R. Gladden Department of Physics National Center for Physical Acoustics The University of Mississippi ncpa.olemiss.edu In viscous Newtonian fluids, support of shear waves is limited to the viscous boundary layer. However, non-Newtonian fluids, which have a shear modulus, support shear waves over much longer distances.…
Friday, September 5, 2014 4:00 p.m. ETC 4.150 Dr. Megan S. Ballard Applied Research Laboratories The University of Texas at Austin www.arlut.utexas.edu A method has been developed to estimate source range in continental shelf environments that exhibit three-dimensional propagation effects. The technique exploits measurements recorded on a horizontal line array of a direct path arrival,…
Friday, April 25, 2014 4:00 p.m. ETC 4.150 Craig Dolder Department of Mechanical Engineering Applied Research Laboratories The University of Texas at Austin http://www.arlut.utexas.edu While the literature contains extensive in situ measurements of scattering by fish schools, significant uncertainties exist with respect to characterizing the size, quantity, and distribution of fish within the schools that…
Friday, April 18, 2014 4:00 p.m. ETC 4.150 Professor Omar Ghattas Department of Mechanical Engineering and Department of Geological Sciences Director of the Center for Computational Geosciences Institute for Computational Engineering and Sciences The University of Texas at Austin Home Inverse problems governed by wave propagation–in which we seek to reconstruct the unknown shape of…
Tuesday, April 8, 2014 11:00 a.m. ETC 2.102 Dr. Linsey Phillips University of North Carolina at Chapel Hill & NC State University Cancer and cardiovascular disease are two of the most common diseases affecting industrialized countries like the United States. Diagnosis and treatment are complex for these diseases, often requiring extensive imaging exams and chronic,…
Friday, April 4, 2014 4:00 p.m. ETC 4.150 Professor Nicole M. Kime Department of Biological Sciences Edgewood University http://biology.edgewood.edu The túngara frog, Physalaemus pustulosus, is a well-known model for investigating the evolution of acoustic communication. All male frogs in the genus Physalaemus produce a species-specific “whine”. Túngara frogs and some populations of its sister species,…