Illuminating tissue with pulsed electromagnetic waves generates acoustic waves inside an object which can be measured and converted into a three dimensional (3d) image. This text is concerned with a twostep reconstruction method where the acoustic pressure is measured with circular integrating detectors. In the first step reconstruction formulas for some kind of projection of the source distrib...

A scattering matrix approach is proposed to avoid numerical instabilities arising with the classical transfer matrix method when analyzing the propagation of plane surface acoustic waves in piezoelectric multilayers. The method is stable whatever the thickness of the layers, and the frequency or the slowness of the waves. The computation of the Green’s function and of the effective permittivity...

A linear theory of dust acoustic (DA) and dust ion-acoustic (DIA) waves in a self-gravitating collisional dusty plasma contaminated by variable-charge impurities is presented for a self-consistent closed system. The ion-drag force arising from the ion orbital motion as well as momentum transfer from all the ions and self-gravitation are taken into consideration. The physical processes, viz., du...

Acoustic waves interact with the human body, head and ears, before reaching the tympanic membranes in the ear canals. In this project we will develop an analytical method to calculate how these acoustic interactions occur. This is a highly nontrivial problem, because the acoustic wave equation (or, for harmonic waves, the Helmholtz equation) has to be solved on the complex geometry of the bound...

A complete ultrasonic measurement model for surface and plate wave inspections is obtained, where all the electrical, electromechanical, and acoustic/elastic elements are explicitly described. Reciprocity principles are used to describe the acoustic/elastic elements specifically in terms of an integral of the incident and scattered wave fields over the surface of the flaw. As with the case of b...

X-ray Bragg diffraction in sagittal geometry on a Y-cut langasite crystal (La3Ga5SiO14) modulated by Λ = 3 µm Rayleigh surface acoustic waves was studied at the BESSY II synchrotron radiation facility. Owing to the crystal lattice modulation by the surface acoustic wave diffraction, satellites appear. Their intensity and angular separation depend on the amplitude and wavelength of the ultrasoni...

We report observation of an inverse energy cascade in second sound acoustic turbulence in He II. Its onset occurs above a critical driving energy and it is accompanied by giant waves that constitute an acoustic analogue of the rogue waves that occasionally appear on the surface of the ocean. The theory of the phenomenon is developed and shown to be in good agreement with the experiments.

Acoustic waves are mechanical waves recently used to activate tissue metabolism by exploiting the cell permeabilization caused by their passage. We report a case of a retroauricular lipoma in a 44-year-old woman affected by multiple symmetric lipomatosis and treated with extracorporeal acoustic wave therapy. The adipose thickness of the lipoma was reduced from 35.8 to 21 mm, with increased soft...

We use molecular dynamics (MD) and particle-in-cell (PIC) simulation methods to investigate the dispersion relation of dust-acoustic waves in a one-dimensional, strongly coupled (Coulomb coupling parameter = r = ratio of the Coulomb energy to the thermal energy = 120) dusty plasma. We study both cases where the dust is represented by a small number of simulation particles that form into a regul...