This paper reports dependency of specific heat and ballistic thermal conductance on cross-sectional geometry (tube versus rod) and size (i.e., diameter and wall thickness), in free-standing isotropic non-metallic crystalline nanostructures. The analysis is performed using dispersion relations found by numerically solving the Pochhammer-Chree frequency equation for a tube. Estimates for the allo...

This paper describes a simulation of signal pathway in an ultrasonic A-scan. It includes transient diffraction acoustic field, transducer response, absorption and dispersion in viscoelastic medium with arbitrary distribution function. The approach selected here aims at developing digital computer simulation of the physical process that underlies these effects. The soft tissue is considered as a...

Speech perception is remarkably robust. This paper examines how acoustic and auditory properties of vowels and consonants help to ensure intelligibility. First, the source-filter theory of speech production is briefly described, and the relationship between vocal-tract properties and formant patterns is demonstrated for some commonly occurring vowels. Next, two accounts of the structure of pref...

Recent achievements of nonlinear acoustics concerning the realization of solitons and solitary waves in crystals and their surfaces attained by nanosecond and picosecond laser ultrasonics are discussed and compared. The corresponding pump-probe setups are described, which allow an all-optical contact-free excitation and detection of short strain pulses in the broad frequency range between 10 MH...

We present an improved model for the dissipation and dispersion in an acoustic resonator filled with xenon near its critical temperature Tc. We test the model with acoustic measurements in stirred xenon that have a temperature resolution of (T - Tc)/Tc approximately 7 x 10(-6). The model includes the frequency-dependent bulk viscosity calculated numerically from renormalization-group theory and...

In this paper, we review results obtained by ultrafast imaging of gigahertz surface acoustic waves in surface phononic crystals with one- and two-dimensional periodicities. By use of quasi-point-source optical excitation, we show how, from a series of images that form a movie of the travelling waves, the dispersion relation of the acoustic modes, their corresponding mode patterns and the positi...

T.C. Fan*, F.Y. Lin, C.S. Hwang, Ian C. Hsu Synchrotron Radiation Research Center, Hsinchu, Taiwan National Tsing Hua University, Hsinchu, Taiwan Abstract Several laboratories have used the pulsed wire method for magnetic field measurement. The acoustic wave distortion of the wire was observed. The limitations of this method were discussed. A pulsed wire system is under test in SRRC on an undul...

We report on a new click type found in Mangetti Dune !Xung (M.D. !Xung) a forward released denti-alveolar lateral click, transcribed [ ||| ]. We present acoustic data showing that ||| is distinct from the "typical" lateral (post-) alveolar ||, and the central (post-) alveolar !, a conclusion supported by synchronic and diachronic analyses of Northern Khoisan [8, 12]. We use Adaptive Dispersion ...

In a plasma containing charged dust grains, the dust acoustic instability (DAI) can be driven by ions streaming through the dust with speed less than the ion thermal speed. When the dust is strongly coupled in the liquid phase, the dispersion relation of the dust acoustic modes changes in a way that leads to an enhancement of the growth rate of the DAI. In this paper, we show how strong couplin...

We study theoretically acoustic phonon modes in nanowire superlattices (NWSLs) composed of cubic materials. We classify the acoustic phonon modes in rectangular and square cross-section NWSLs, based on group theory. For NWSLs consisting of GaAs and AlAs, we calculate numerically the dispersion relations of each phonon mode and corresponding displacement fields. We examine the effects of both th...