One research goal developed from conducted shallow water (SW) acoustic transmission experiments in sandy-silty areas [1] revealed a nonlinear power law frequency-dependent attenuation at lower frequencies ( ≤ 1 kHz ) consistent with results reviewed in [2-4] and the observations by the ONR-HEP program. The Biot Theory [5] predicts that the sandysediment frequency-dependent attenuation should be...

We study the mathematical model of thermoacoustic tomography in media with a variable speed for a fixed time interval Œ0;T  so that all signals issued from the domain leave it after time T . In case of measurements on the whole boundary, we give an explicit solution in terms of a Neumann series expansion. We give almost necessary and sufficient conditions for uniqueness and stability when the ...

Ocean acoustic sound speed profile (SSP) estimation requires the inversion of acoustic fields using limited observations. Compressive sensing (CS) asserts that certain underdetermined problems can be solved in high resolution, provided their solutions are sparse. Here, CS is used to estimate SSPs in a range-independent shallow ocean by inverting a non-linear acoustic propagation model. It is sh...

The sound speed and the density of a series of blood samples was measured in a temperature range from 20 degrees C to 40 degrees C. An expression was derived from a least square fit which related the sound speed in human blood in this temperature range to the blood density and to the total protein concentration, respectively. The data were obtained from the measurement of sound speed and densit...

Objectives: The purpose of this in vitro study was to evaluate the microleakage of cervical cavities prepared by Er:YAG laser or high-speed hand piece and bur. Methods: This in vitro experimental study was performed on 40 sound permanent third molar teeth randomly assigned into two equal groups (n=20). In the first group, high-speed hand piece and bur and in the second group Er:YAG la...