In underwater environment the acoustical wave can transmit a long ranges away from the transmitter than the electromagnetic wave does. So far, the piezoelectric ceramic is still the best candidate as acoustical telemetry transmitters in underwater applications. The impedance matching on the interface between electro-acoustical transducer and electrical transmitter has been the most important su...

In this paper, we report on surface-plasmon-resonance enhancement of the time-dependent reflection changes caused by laser-induced acoustic waves. We measure an induced several acoustical modes, such as longitudinal, quasi-normal, and surface waves, a factor 10–20. show that longitudinal quasi-normal modes are enhanced in wings plasmon polariton resonance. The wave-induced peak attribute to wav...

the course of consecutive experiments in this report aimed to a research or introductory identification about mechanical and acoustical properties of maple (acer velutinum) wood. studied factors were included quality factor (due to internal friction), acoustic coefficient, acoustical conversion efficiency as well as the modulus of elasticity (young’s modulus) which they were all accomplished us...

In atmospheric acoustics, the subject of surface waves has been an area of discussion for many years. The existence of an acoustic surface wave is now well established theoretically. The mathematical solution for spherical wave propagation above an impedance boundary includes the possibility of a contribution that possesses all the standard properties for a surface wave. Surface waves exist whe...

A theory is provided for the detection efficiency of diffuse light whose frequency is modulated by an acoustical wave. We derive expressions for the speckle pattern of the modulated light, as well as an expression for the signal-to-noise ratio for the detector. The aim is to develop a new imaging technology for detection of tumors in humans. The acoustic wave is focused into a small geometrical...

Acoustic wave propagation and attenuation in catalytic converters are investigated in the present study. The relationships for wave propagation in a catalytic monolith are derived first and then coupled to the wave propagation in tapered ducts which are commonly placed at either end of the monolith. Analytical and finite element approaches are used to solve the resulting coupled system of equat...

In recent experiments and numerical studies, a leaky surface wave has been observed at the surface of an isotropic homogeneous elastic solid. This paper gives a detailed description of this leaky surface wave and explains its origin from the fundamental differential equations. Theoretically, the leaky surface wave arises from the complex conjugate roots of the Rayleigh equation. The complex con...