The advantage of using the normal component of the particle velocity rather than the sound pressure in the hologram plane as the input of conventional spatial Fourier transform based near field acoustic holography (NAH) and also as the input of the statistically optimized variant of NAH has recently been demonstrated. This paper examines whether there might be a similar advantage in using the p...

We study a model of flocking for a very large system (N=320,000) numerically. We find that in the long wavelength, long time limit, the fluctuations of the velocity and density fields are carried by propagating sound modes, whose dispersion and damping agree quantitatively with the predictions of our previous work using a continuum equation. We find that the sound velocity is anisotropic and ch...

A novel approach for measuring the speed of sound in fluids with scattering particles is presented. Potential fields of application for sound velocity measurements in fluids are process control, environmental measurement technology and medicine, where sound velocity can be used as an indicator of temperature, concentration or mass density. Similar to the pulsed Doppler application, the method a...

In this article, experimentally determined values of sound velocity in LPG in a temperature range (–23...+55) °C are presented. The measurements were taken using two industrial LPG samples in a standard five liter pressurized gas tank. The propagation time of a ultrasonic signal with the frequency of 0.7 MHz was measured. To increase the accuracy of measurement, a pulse-phase method was applied...

The effects of loud sound on the microvasculature of the cochlea are not well characterized or understood. Morphological changes in the stria vascularis and changes in blood flow are known to occur during or following sound stimulation, however, the effects on cochlear blood flow appear to be complex. Studies have shown that noise exposure may produce increases in blood flow, decreases in blood...

A cosmological first-order phase transition gravitational wave could provide a novel approach to studying the early Universe. In most cases, acoustic from sound mechanism is dominant. Considering different velocities in symmetric and broken phases, we study velocity effects on spectra shell model. We demonstrate that obviously modify peak frequency amplitude of power spectra. Therefore, taking ...