The Soret coefficient of acetone/water mixtures has been experimentally determined by a recently developed thermal lens technique ͓Appl. Phys. Lett. 94, 051103 ͑2009͔͒. The behavior of the Soret coefficient was reproduced, including its sign change with composition. For concentrations around the equimolar ones, we have also confirmed the disagreement between the experimental and simulation data that had previously been reported by Ning and Wiegand ͓J. Chem. Phys. 125, 221102 ͑2006͔͒ using a transient holographic grating technique of thermal diffusion forced Rayleigh scattering. Additionally, we compare our experimental results with the theoretical values predicted by a recently developed viscous energy model ͓J. Chem. Phys. 130, 064506 ͑2009͔͒.

We report an experimental study of the temporal and spatial dynamics of shock waves, cavitation bubbles, and sound waves generated in water during laser shock processing by single Nd:YAG laser pulses of nanosecond duration. A fast ICCD camera (2 ns gate time) was employed to record false schlieren photographs, schlieren photographs, and Mach-Zehnder interferograms of the zone surrounding the laser spot site on the target, an aluminum alloy sample. We recorded hemispherical shock fronts, cylindrical shock fronts, plane shock fronts, cavitation bubbles, and phase disturbance tracks.

We compare the radiative transfer equation for media with constant refractive index with the radiative transfer equation for media with spatially varying refractive indices [J. Opt. A Pure App. Opt. 1, L1 (1999)] and obtain approximate conditions under which the former equation is accurate for modeling light propagation in scattering media with spatially varying refractive indices. These conditions impose restrictions on the variations of the refractive index, the gradient of the refractive index, the divergence of the rays, the frequency of modulation, and the widths of light pulses, which are related to the mean refractive index, the absorption coefficient, and the reduced scattering coefficient of the medium. Each condition is geometrically interpreted. Some implications of the results are discussed.

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