Plasma-maser instability of the ion acoustics wave in the presence of lower hybrid wave turbulence in inhomogeneous plasma

A theoretical study is made on the generation mechanism of ion acoustics wave in the presence of lower hybrid wave turbulence field in inhomogeneous plasma on the basis of plasma-maser interaction. The lower hybrid wave turbulence field is taken as the low-frequency turbulence field. The growth rate of test high frequency ion acoustics wave is obtained with the involvement of spatial density gradient parameter. A comparative study of the role of density gradient for the generation of ion acoustics wave on the basis of plasma-maser effect is presented. It is found that the density gradient influences the growth rate of ion acoustics wave.     

Kinematic Parameters of a Two-Phase Flow in a Rectangular Channel

A kinematic two-phase flow pattern formed in a rectangular channel due to the interaction of a gas flow with an initially stationary or moving water layer is investigated. Using laser diagnostics and hot-wire methods, the velocity distributions in the water and the air are found for a stratified flow regime.     

Optical Buffering and Mechanisms for Its Occurrence

We investigate a mathematical nonlinear-optics model that is a scalar parabolic equation on a circle with a small diffusion coefficient and a deviating spatial argument. We establish that the problem under consideration is characterized by the so-called buffering phenomenon, i.e., under an appropriate choice of the parameters, the coexistence of an arbitrary fixed number of time-periodic stable solutions of the problem can be obtained. We reveal the mechanisms for the occurrence of this phenomenon.     

The attenuation of electromagnetic waves due to atmospheric fog

The propagation of EM waves through atmospheric fog is reviewed across the spectrum from microwave to optical frequencies. Analytical approaches are considered including Mie computation, and the results compared with published experimental results. Further measurements are called for to clarify discrepancies.     

Diffraction of SH waves at a mixed interface

Summary We study the diffraction of SH-type elastic waves propagating along the plane interface between two dissimilar elastic half-spaces. It is assumed that the contact between the half-spaces is perfect except for a part of semi-infinite extension where the contact is loosely coupled. We use the Wiener-Hopf technique to obtain the diffracted field in a closed form.     

The influence of elastic waves on dynamic stress intensity factors (two-dimensional problems)

Summary In this paper, an indirect boundary integral equation method for the solution of dynamic crack problems is presented. The Laplace transform method is used to derive the fundamental solutions for the opening mode (mode I) and the sliding mode (mode II) displacement discontinuity. Accurate dynamic stress intensity factorsK _N (t) (N=I,II) resulting from different time-dependent loads on the crack surface are obtained. The specific influences of the various elastic waves on the stress intensity factors can be clearly seen from the results.On leave Central-South University of Technology Changsha, P.R. China     

Waves in front of the Venetian littoral

Summary The second-generation HISWA model, specifically developed for shallow water areas, was used to estimate the wave conditions in front of the Venetian littoral. The model is based on the wave action equation, and it includes conservative interactions with bottom and currents, generation by wind and dissipation by bottom friction and breaking. A detailed sensitivity analysis has been carried out on the main processes that affect the output of the model. The performance of the model has then been checked by comparison with laboratory and field data. Finally, the HISWA model has been applied to several severe storms which have occurred in the Northern Adriatic and also to extreme wave conditions in the same area, thus allowing the corresponding wave conditions at the coast to be estimated. The results suggest that wave evolution towards the coast is greatly influenced by bottom friction in intermediate water depth and by breaking in shallow water. These processes could lead to saturation conditions during extreme wave events.     

A missing link: What is behind de Broglie's “periodic phenomenon”?

The present work constitutes an attempt to give the interpretation of de Broglie's internal periodic phenomenon which ascribes the frequencym ₀ c ²/h to each single entity in its eigensystem of coordinates. This phenomenon provides existence in principle of the ideal proper-time scale, making it possible to identify the geometric proper-time interval with a physically existing one, thus ensuring the realization of basic postulates of the relativity theory. According to the latter, neither time nor de Broglie's frequency are invariant with respect to the Lorentz transformation of the coordinate system. A search for the fundamental invariant demands passing over to dimensionless quantities, and we suggest to consider as such the integer numbers. Then it is the entity's periodic phenomenon which, after multiplying by the lasting proper-time, results in the open ordered sequence of natural numbers. The progressing course of numbers is ensured by the time course, whilst their ordering is connected with coherence. Such a sequence of numbers, once appeared in time, has to be conserved in space-time, demanding the periodic phenomenon's phase to be invariant with respect to the Lorentz transformation. This, in its turn, yields de Broglie's waves of matter, which are at the bottom of quantum physics. Thus, the most intrinsic feature of a fundamental entity has to be identified with its internal frequency, in order to ensure the actual existence of the sequence of natural numbers as the basic object of arithmetic.     

Quartic B‐spline collocation algorithms for numerical solution of the RLW equation

The collocation method based on quartic B‐spline interpolation is studied for numerical solution of the regularized long wave (RLW) equation. The time‐split RLW equation is also solved with the quartic B‐spline collocation method. Numerical accuracy is tested by obtaining the single solitary wave solution. Then, interaction, undulation and evolution of solitary waves are studied. Solutions are compared with available results. Conservation quantities are computed for all test experiments. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2007