We discuss the occurrence of negative specific heat in a nonextensive system which has an equilibrium second-order phase transition. The specific heat is negative only in a transient regime before equilibration , in correspondence to long-lasting metastable states. For these states standard equilibrium Bolzmann-Gibbs thermodynamics does not apply and the system shows non-Gaussian velocity distr...

The drift velocity of an auroral arc is compared with the component of F-region plasma velocity in the same direction for ten cases where the arc is seen to move steadily equatorward for several minutes without any major change in appearance or orientation. In most cases the two velocities are close, but on two occasions the drift velocity of the arc is much higher than the plasma velocity. Fro...

It is considered the electromagnetic wave in the frame moving transverse to the wave. Due to the velocity of the frame with respect to a preferred reference frame the oscillations of phase arise. The oscillations of phase yield the third order effect which can be seen in the Michelson-Morley experiment. The effect due to the velocity of the earth with respect to CMB is in agreement with the ani...

Flow velocity spectra of main arteries in 24 healthy adult subjects and 21 healthy aged subjects were transcutaneously studied using the directional ultrasonic Doppler technique. I) The instantaneous flow velocity spectrum is continuous throughout a pulse cycle, and intensified near the instantaneous maximum velocity, especially in the earlypart ofa pulse cycle. 2) No reverse flow phase is obse...

We measured a cross-section of able-bodied (AB) men (n = 175) and men with chronic spinal cord injury (SCI) (n = 33) residing in the community, 14 to 65 years old, to identify associations between dietary factors, physical activity, health status, and mechanical properties of long bones assessed by phase velocity measurement of flexural waves in the tibia during the second to seventh decades. T...

In this article, we analyze the dynamic characteristics of head wave in multi-layered half-space media models with high-velocity layer or low-velocity layer, and the model with a continuous transition-zone between the crust and the mantle by using synthetic seismogram. It is concluded that the dynamic characteristics of head wave are sensitive to the thickness and velocity of the high-velocity ...

Phase-Resolved Doppler Optical Coherence Tomography (PR-DOCT) allows visualization and characterization of the location, direction, velocity, and profile of flow activity embedded in a static sample structure. The detectable Velocity Dynamic Range (VDR) of each particular PR-DOCT system is governed by a detectable Doppler phase shift, a flow angle, and an acquisition time interval used to deter...

Quantum phase slips are the primary excitations in one-dimensional superfluids and superconductors at low temperatures but their existence in ultracold quantum gases has not been demonstrated yet. We now study experimentally the nucleation rate of phase slips in one-dimensional superfluids realized with ultracold quantum gases, flowing along a periodic potential. We observe a crossover between ...

Electromechanical speakers are commonly used as actuators in acoustic control applications and have non-constant velocity frequency response making them poor actuators. Velocity feedback compensation designed to minimize magnitude and phase variations in speaker velocity response is developed in this work. A proportional feedback compensator acting on the error between desired velocity input an...