Launch vehicles use ablative nozzle liners to function under very high thermal and erosive environments. In solid motor nozzle throats, graphite or carbon phenolic materials are used because of their high heat of ablation and erosion resistance. Ultrasonic testing is implemented as the primary NDT technique for throat insert liners by almost replacing radiography testing. Though introduced for ...

BACKGROUND We hypothesized that longitudinal pulmonary arterial deformation during the cardiac cycle reflects pulmonary arterial capacitance. To examine this hypothesis, we assessed whether tissue Doppler-derived pulmonary annular motion could serve as a novel way to evaluate pulmonary arterial capacitance in pediatric patients with ventricular septal defect (VSD). METHODS In this prospective...

Three series of experiments were conducted to study the effect of Reynolds number, near-wall perturbation and background turbulence on the characteristics of smooth open channel flows. Measurements were carried out using a laser Doppler anemometer. The variables of interest include the mean velocity, the turbulence intensity, probability density distribution and Gram-Charlier series coefficient...

A deterministic cellular automaton rule defined on the Moore neighbourhood is studied as a model of epidemic propagation. The directed nature of the interaction between cells allows one to introduce the dependence on a disorder parameter that determines the fraction of “in-phase” cells. Phase-disorder is shown to produce peculiar changes in the dynamical and statistical properties of the differ...

We present experimental evidence that the motion of point defects in thermal convection patterns in an inclined fluid layer is well described by Tsallis statistics with an entropic index q ≈ 1.5. The dynamical properties of the defects (anomalous diffusion, shape of velocity distributions, power-law decay of correlations) are in good agreement with typical predictions of nonextensive models, ov...

We study the scenario of electroweak baryogenesis mediated by nonsuperconducting cosmic strings. This idea relies upon electroweak symmetry being restored in a region around the core of the topological defect so that, within this region, the rate of baryon number violation is enhanced. We compute numerically how effectively baryon number is violated along a cosmic string, at an epoch when the b...

Asymptotic behavior of the solution of the moving oscillator problem is examined for large values of the spring stiffness for the general case of nonzero beam initial conditions. In the limit of infinite spring stiffness, the moving oscillator problem for a simply supported beam is shown to be not equivalent in a strict sense to the moving mass problem; i.e., beam displacements obtained by solv...

The positions in the HR diagram and the kinematic characteristics of rapidly oscillating and non-oscillating chemically peculiar stars are obtained using new Hipparcos proper motions and parallaxes, and our own radial velocity measurements. We find that rapidly oscillating stars, as a group, are (−0.47±0.34) mag above the zero-age main sequence (ZAMS), while the non-oscillating stars are (−1.20...

A statistical theory is presented for the ordering dynamics of a system with a complex order parameter quenched below the critical temperature. On the basis of a picture that string·like defects are formed in the early stage of the ordering process, the disappearing process of the defects is studied. We obtain the time evolution of the defect density and its two-point correlation function, whic...

The investigation of hydrodynamic models with partially penetrable obstacles has been initiated by the recent progress in the development of free flow turbines [l] for the purpose of estimating their efficiency limit [2]. In the previous paper [3], an explicitly solvable analog of the Kirchhoff cavitation flow was obtained. As in the classical situation, the main deficiency of the Kirchhoff mod...