Our goal is the rapid and accurate measurement of upper-ocean vertical sound velocity (and hence temperature) profiles in the ocean. The objective is to obtain range resolved (»1 m) measurements of temperature and sound velocity over a range of »100 m at an accuracy of 0.1°C and 0.2 m/s, respectively. To this end we are developing an innovative Brillouin LIDAR concept. Present results provide c...

We consider an ideal gas of massive hadrons in thermal and chemical equilibrium. The gas expands longitudinally in an adiabatic way. This evolution for a baryonless gas reduces to a hydrodynamic expansion. Cooling process is parametrized by the sound velocity. The sound velocity is temperature dependent and is strongly influenced by hadron mass spectrum. ∗Work partially supported by the Polish ...

To clarify the postulate that turbulence may produce ejection murmurs, point velocity and sound were measured in the ascending aorta of 13 subjects: six with normal aortic valves, six with aortic valvular disease, and one with a Bjork-Shiley prosthetic aortic valve. Velocity was measured with a catheter-tip hot film anemometer probe, and sound was measured with a catheter-tip micromanometer. Ej...

Finite-difference, time-domain (FDTD) calculations are typically performed with partial differential equations that are first order in time. Equation sets appropriate for FDTD calculations in a moving inhomogeneous medium (with an emphasis on the atmosphere) are derived and discussed in this paper. Two candidate equation sets, both derived from linearized equations of fluid dynamics, are propos...

2014 Effects of crystal growth on the fourth sound propagation are studied in the framework of hydrodynamics. The particular system we have in mind is superfluid 4He in a grafoil superleak. Solid 4He is formed on the surface of graphite and it grows continuously when the pressure of liquid is increased during passage of a sound wave. Sound velocity and Doppler shifts for steady superfluid flow ...

We report experimental observations of sound waves in a granular material during resonant silo discharge called silo music. The grain motion was tracked by high-speed imaging while the resonance of the silo was detected by accelerometers and acoustic methods. The grains do not oscillate in phase at neighboring vertical locations, but information propagates upward in this system in the form of s...

The major problem in the fruit juice industry is associated with juice quality deterioration due to the cloud loss of juice concentrates by the enzymatic reaction of pectinmethylesterase enzyme (PME, EC 3.1.1.11). During pectin hydrolysis, pectin and water are transformed into polygalacturonic acid (pectate) and methanol by the action of PME. In this work, a low-intensity ultrasonic technique i...