Gold nanoparticles (AuNP) - polydimethylsiloxane (PDMS) composites are promising materials for photoacoustic (PA) generation owing to their high thermal dilatation coefficient, small capacity and acoustic impedance close water....

In photo-acoustic imaging, energy absorption causes thermo-elastic expansion of optical absorbers, which in turn leads to propagation of a pressure wave. Recently, we have developed an efficient method for locating small absorbing regions inside a bounded domain from boundary measurements of the induced pressure wave and reconstructing the absorbed density. However, it is the absorption coeffic...

To effectively use photoacoustic tomography to obtain cross-sectional images, a combination of a focused laser illumination and focusing acoustic detectors is used. In this work, we discuss how to incorporate cylindrically shaped focusing detectors in the mathematical modelling of photoacoustics and derive approximative reconstruction formulas. Moreover, we show how such focusing detectors comb...

The applicability and performance of linear solvation energy relationships (LSERs) as models of responses from polymer-coated acoustic-wave vapor sensors are critically examined. Criteria for the use of these thermodynamic models with thickness-shear-mode resonator (TSMR) and surface-acoustic-wave (SAW) vapor sensors are clarified. Published partition coefficient values derived from gas-liquid ...

We apply the CIP (Cubic Interpolated Profile) scheme to the numerical simulation of the acoustic wave propagation based on characteristic equations.The CIP scheme is based on a concept that both the wavefield and its spatial derivative propagate along the same characteristic curves derived from a hyperbolic differential equation. We describe the derivation of the characteristic equations for th...

We have derived the set of reference scaling parameters yielding collapse of isentropic acoustic and thermoacoustic (or heat-release-induced) waves across different pure compressible fluids with an assigned equation of state. The resulting reference pressure and velocity are consistent with classic acoustic scaling. The reference temperature and heat release rate need to be expressed in terms o...

This thesis presents a method to investigate the extent to which articulatory based acoustic features can be exploited to reduce ambiguity in automatic speech recognition search. The method proposed is based on a lattice re-scoring paradigm implemented to integrate articulatory based features into automatic speech recognition systems. Time delay neural networks are trained as feature detectors ...

Except in the deep ocean, the seabed has a major influence on low-frequency acoustic propagation. The formulation of an adequate geoacoustic model of the seabed is therefore one of the most important tasks facing anyone carrying out acoustic propagation modelling to predict underwater sound levels in coastal and continental shelf waters. It is often assumed that seabed layering on scales signif...

In this study, propagation characteristics of surface acoustic waves in a layered piezoelectric structure (AlN/128°Y-X LiNbO3) are investigated. The phase velocity and coupling coefficient of the layered structure with interdigital transducers and/or metal thin films deposited at various interfaces will be calculated numerically. The effects of the polarity of 128°Y-X LiNbO3 on SAW characterist...

Acoustic bottom-interacting measurements from the Shallow Water '06 experiment experiment (frequency range 1-20 kHz) are presented. These are co-located with coring and stratigraphic studies showing a thin (approximately 20 cm) higher sound speed layer overlaying a thicker (approximately 20 m) lower sound speed layer ending at a high-impedance reflector (R reflector). Reflections from the R ref...