We propose a simple two-dimensional acoustic crystal to realize topologically protected edge states for acoustic waves. The acoustic crystal is composed of a triangular array of core-shell cylinders embedded in a water host. By utilizing the point group symmetry of two doubly degenerate eigenstates at the Γ point, we can construct pseudo-time-reversal symmetry as well as pseudo-spin states in t...

Results of numerical 3D simulations of propagation of acoustic waves inside the Sun are presented. A linear 3D code which utilizes realistic OPAL equation of state was developed by authors. Modified convectively stable standard solar model with smoothly joined chromosphere was used as a background model. High order dispersion relation preserving numerical scheme was used to calculate spatial de...

Stability is examined for an optically thick, slim accretion disk around a black hole. We derive the fourth-order dispersion relation in a framework of a linear stability analysis. Also we obtain the approximate second-order relation which is convenient to diagnose the stability. By solving these relations for slim disk models with a low viscous parameter α, we find that not only the viscous an...

Four thin-film adhesion characterization methods are proposed. Two of them are surface acoustic wave based and the two others emphasize the complementary nature between acoustic microscopy, scratch test and tensile experiments. A continuous wave scanning acoustic microscope was used to propagate surface modes in the specimen and to measure the surface acoustic wave velocity as a function of the...

Acoustically sensitive emulsion droplets composed of a liquid perfluorocarbon have the potential to be a highly efficient system for local drug delivery, embolotherapy, or for tumor imaging. The physical mechanisms underlying the acoustic activation of these phase-change emulsions into a bubbly dispersion, termed acoustic droplet vaporization, have not been well understood. The droplets have a ...

Impulsive Stimulated Thermal Scattering (ISTS) is an in-situ non-destructive characterization technique based on laser excitation and detection of surface acoustic waves (SAWs) for mechanical properties of thin metal films in the microelectronic industry. In this work, the effect of elastic anisotropy from silicon wafers on ISTS measurements has been studied. It has been shown that for films of...

We study theoretically the contribution of quantum effects to exciton diffusion coefficient in atomically thin crystals. It is related weak localization caused by interference excitonic wavefunctions on trajectories with closed loops. Due a inelasticity exciton-phonon interaction effect present even if excitons are scattered long-wavelength acoustic phonons. consider longitudinal phonons linear...

Using first-order perturbation theory and deformation potential approximation, the interaction of electrons and holes with acoustic and optical phonons is investigated in silicon nanowires SiNWs with different diameters and crystallographic axis orientations. The electronic band structures for 110 and 100 SiNWs are obtained from a sp3d5s tight-binding scheme, while a continuum model is assumed ...

The vortex ow which follows intense sound propagating in a bubbly liquid, is considered. The reasons for acoustic streaming are both nonlinearity and dispersion. That makes streaming especial as compared with that in a Newtonian uid. Conclusions concern the vortex ow induced in a half-space by initially harmonic or impulse Gaussian beam. The vortex ow recalls a turbulent ow with increasing in t...