this paper presents the design and simulation of a typical ka band satellite beacon receiver for propagation experimentation. using satellite beacon signal as a reference signal in satellite wave propagation study, is one of the most important methods. satellite beacons are frequently available for pointing large antennas, but such signals can be used for measuring the effect of natural phenome...

We report quantitative measurements of both wave number selection and defect motion in nonequilibrium hexagonal patterns. A novel optical technique ("thermal laser writing") is used to imprint initial patterns with selected characteristics in a Bénard-Marangoni convection experiment. Initial patterns of ideal hexagons are imposed to determine the band of stable pattern wave numbers while initia...

A Lamb wave-based crack detection method for aluminum plates health monitoring is developed in this paper. Piezoelectric disks are employed to actuate and capture the Lamb wave signals. The position of crack is assumed to be aligned with the sensor and actuator.  Extraction of high quality experimental results of lamb wave propagation in a plate-like structure is considerably complicated due to...

Transfer matrix formalism is widely used in modeling periodic heat diffusion layered structures. Due to an intrinsic numerical instability issue, this fails at high heating frequencies and/or thick Inspired by its success wave propagation, we develop a numerically stable scattering framework model stratified solid media. As concrete example, apply methodology the 3ω method. We first validate ou...

The world communicates to our senses of vision, hearing, and touch in the language of waves, because light, sound, and even heat essentially consist of microscopic vibrations of different media. The wave nature of light and sound has been extensively investigated over the past century and is now widely used in modern technology. However, the wave nature of heat has been the subject of mostly th...

Of the many ongoing controversies regarding the workings of the sarcoplasmic reticulum (SR) in cardiac myocytes, two unresolved and interconnected topics are 1), mechanisms of calcium (Ca(2+)) wave propagation, and 2), speed of Ca(2+) diffusion within the SR. Ca(2+) waves are initiated when a spontaneous local SR Ca(2+) release event triggers additional release from neighboring clusters of SR r...

Second initial boundary problem in narrow domains of width ǫ ≪ 1 for linear second order differential equations with nonlinear boundary conditions is considered in this paper. Using probabilistic methods we show that the solution of such a problem converges as ǫ ↓ 0 to the solution of a standard reaction-diffusion equation in a domain of reduced dimension. This reduction allows to obtain some r...

A reaction-diffusion model for the propagation of an idealized forest fire is revisited to include the effect of wind on the speed of propagation. We study the existence of one-dimensional travelling wave solutions. When the wind velocity is zero or when the wind blows from the burning region, the existence and uniqueness of the travelling wave is proved. In the case when the wind blows into th...