<p style="text-indent:20px;">This paper concerns continuous subsonic-sonic potential flows in a two dimensional convergent nozzle, which is governed by free boundary problem of quasilinear degenerate elliptic equation. It shown that for given nozzle perturbation an straight one, and mass flux, there exists uniquely flow whose velocity vector along the normal direction at inlet sonic curve...

The study of the fluid dynamics of violent volcanic eruptions by laboratory experiment is described, and the important fluid-dynamic processes that can be examined in laboratory models are discussed in detail. In prelim•inary experiments, pure gases are erupted from small reservoirs. The gases used are Freon 12 and Freon 22, two gases of high molecular weight and high density that are good anal...

The Northern searobin (Prionotus carolinus) contracts its paired sonic muscles alternately rather than simultaneously during sound production. This study describes this phenomenon and examines its effect on sound production by recording sound and EMGs during voluntary and electrically stimulated calls. Sounds produced by a single twitch resulted in a two-part sound representing contraction and ...

We study relaxation of a moving spin qubit caused by phonon noise. As we vary the speed of the qubit, we observe several interesting features in spin relaxation and the associated phonon emission, induced by Doppler effect. In particular, in the supersonic regime, the phonons emitted by the relaxing qubit is concentrated along certain directions, similar to the shock waves produced in classical...

Inspired by a theory of embodied music cognition, we investigate whether music can entrain the speed of beat synchronized walking. If human walking is in synchrony with the beat and all musical stimuli have the same duration and the same tempo, then differences in walking speed can only be the result of music-induced differences in stride length, thus reflecting the vigor or physical strength o...

Using AdS/CFT, we calculate the energy density of a quark moving through a thermal state of N = 4 super-Yang-Mills theory. Relying on previous work for momentum-space representations as well as asymptotic behaviors, we Fourier transform to position space and exhibit a sonic boom at a speed larger than the speed of sound. Nontrivial structure is found at small length scales, confirming earlier a...

We investigate self-similar dynamical processes in an isothermal self-gravitational fluid with spherical symmetry. In reference to earlier complementary solution results of Larson, Penston, Shu, Hunter and Whitworth & Summers, we further explore the ‘semi-complete solution space’ from an initial instant t→ 0 to a final stage t→ +∞. These similarity solutions can describe and accommodate physica...

In this present article, we study different accretion properties regarding viscous of dark energy. Modified Chaplygin gas is chosen as the energy candidate. Viscosity encountered with help Shakura-Sunyaev viscosity parameter. We sonic speed vs radial distance curves. compare between adiabatic and dominated cases follow that falls go nearer to central gravitating object. As imposed, a threshold ...