panels with a genetic algorithm, Applied Acoustics, Volume 70, Issue 3, March 2009, Pages 416-425, ISSN 0003-682X, http://dx.doi.org/10.1016/j.apacoust.2008.06.003. 1 Optimal design of acoustical sandwich panels with a genetic algorithm Tongan Wang, Shan Li, Steven R. Nutt 1. University of Southern California, 3651 Watts Way, VHE 602, Los Angeles, CA 90089, United States Abstract: An optimizati...

Propagation of waves in elastic porous media, e.g. polymeric foams, is described by Biot-Allard’s theory [1]. Two classes of characteristic parameters are needed to describe the porous media in this theory. First, non-acoustic parameters: porosity φ, thermal characteristic length Λ′, viscous characteristic length Λ, flow resistivity σ, and tortuosity α∞ which are used in Johnson-Champoux-Allard...

Although listeners are able to decode the underlying emotions embedded in acoustical laughter sounds, little is known about the acoustical cues that differentiate between the emotions. This study investigated the acoustical correlates of laughter expressing four different emotions: joy, tickling, taunting, and schadenfreude. Analysis of 43 acoustic parameters showed that the four emotions could...

Elimination of stator oscillations in electromotors is among the least studied, but important problems that can influence the electric performance, mechanical wear and tear and acoustical noise. In this paper, we focus on a switch reluctance motor (SRM) designed and prototyped for eventual production in Iran. The stator oscillation problems due to radial forces in SRMs have been reported as mor...

To perform a non-destructive evaluation of wood, the Christoffel equation is frequently used to describe the relationship between the ultrasonic wave velocity and the mechanical parameters. In the context of acoustical tomography imaging of standing trees, the key contribution of this numerical study is to determine the influence of mechanical parameters of the wood radial-tangential plane on t...

Objective(s): Bioactive silicate ceramics have favorable features for applying as off-the-shelf bone and artificial tissue. Calcium silicate can enhance the generation of an immediate bond with host bone without an intervening rough surface in the bone layer. However, the silicate bioceramics have some drawback regarding their mechanical properties and chemical stabilities. Materials and Method...