Page 5 - Winter 2008

Acoustics Today
A Publication of the Acoustical Society of America
Volume 4, Issue 1 January 2008
Cover: The cover shows a photograph of a rectangular aluminum plate used in a Time Reversal (TR) experiment with the resulting image (inserted above) obtained at the focal time (specifically, the spatial distribution of the mag- nitude of the out-of-plane velocity). Note the well- defined peak in the inserted image that corresponds to the original source location. Note also that other energy exists elsewhere at the focal time. This is due to the fact that the experimental TR focusing process is never per- fect due to a variety of factors that lead to energy leakage to other locations.
Articles:
5 Time Reversal—Brian E. Anderson, Michael Griffa, Caréne Larmat, Timothy J. Ulrich, Paul A Johnson
Time reversal is a method of focusing energy onto a spe- cific location in space and time, with potential applica- tions in nearly every field of acoustics.
17 Resonances and Time-of-Flight: Ultrasonic Probes of Condensed Matter Go Digital—Albert Migliori
Both resonance and time-of-flight techniques for elastic modulus measurement are now accessible to everyone. Both methods have deep similarities based on the most precisely measured quantities in all of science, frequency and time, but advances in digital signal acquisition and processing have transformed these techniques into something no longer recognizable by the pioneers.
23 Sound System Design—Marshall Long “But the computer said it would be OK.”
Departments:
31 Standards: Animal Bioacoustics Subcommittee Debuts—David K. Delaney and Susan B. Blaeser
For the first time ever, one of ASA’s ANSI-Accredited Standards Committee has formed a Subcommittee— Animal Bioacoustics.
35 National News—Elaine Moran
Acoustical news from around the country.
39 International News—Walter G. Mayer Acoustical news from around the world.
43 Books and Publications—Dick Stern
New and recent publications, reports, and brochures on acoustics.
45 Instrumentation—Dick Stern
New and recent acoustic instrumentation and news about acoustic instrument manufacturers.
46 The Business of Acoustics—Dick Stern 47 Passings—Dick Stern
A farewell to colleagues—D.F. Muster, L.H. Sibul
Business Directory
49 Business card advertisements
51 Classified
Classified advertisements, including positions offered and positions desired.
52 Index to Advertisers
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