For over 1000 years electromagnetic radiation has been utilized for long-distance communication. heliographs, telegraphs, telephones and radio have all served our previous communication needs. Nevertheless, electromagnetic radiation has one major difficulty: it is easily absorbed. In this paper we consider a totally different radiation, a radiation that is not easily absorbed: gravitational rad...

A spectrum of weakly guided waves in the solar atmosphere at frequencies as high as 100 mHz (10 s period) has been detected with high-cadence solar image sequences from the Transition Region and Coronal Explorer (TRACE) spacecraft. The waves are visible in the TRACE 1600 far-UV passband and were detected as faint Å ridges in an energy spectrum produced by Fourier transformation of subfields of ...

A miniaturized multidimensional magnetic probe is developed for application in a low-temperature plasma environment. A very high sensitivity for low-frequency magnetic field fluctuations with constant phase run, a very good signal-to-noise ratio combined with an efficient electrostatic pickup rejection, renders the probe superior compared with any commercial solution. A two-step calibration all...

The finite-difference (FD) method described here is specially developed to model high-frequency Rayleigh-wave propagation in near-surface mediums. Although many FD programs existed for earthquake research and oil exploration, none has been developed to model high-frequency Rayleigh-wave propagation in near-surface elastic mediums when the source and all receivers are on the free-surface. The sc...

With respect to the dramatic increasing use of electronically communicators and wireless modems, concerns have been raised about the possible effects of emitted electromagnetic radiation on human brain. In this paper, the effects of high-frequency wireless modem waves on the brain signal are investigated. To this end, the Electroencephalograph (EEG) recording of 15 volunteers is examined in fou...

Elastic ray theory is a high frequency asymptotic approximation of solution of elastodynamic equation, and is widely used in seismology. In this paper, the form invariance under a general spatial mapping and high frequency wave control have been examined by transformation method. It is showed that with the constraint of major and minor symmetry of the transformed elastic tensor, the eikonal equ...

We propose a tunable resonant sensor to detect gravitational waves in the frequency range of 50-300 kHz using optically trapped and cooled dielectric microspheres or microdisks. The technique we describe can exceed the sensitivity of laser-based gravitational wave observatories in this frequency range, using an instrument of only a few percent of their size. Such a device extends the search vol...

Three-wave interactions (M ↔ P + Q) of plasma waves propagating parallel to the mean magnetic field at frequencies below the electron cyclotron frequency are considered. We consider Alfvén–ion-cyclotron waves (L), fast-magnetosonic–whistler waves (R), and ion-sound waves (I). Especially the weakly turbulent low-beta plasmas like the solar corona are studied, using the cold-plasma dispersion rel...

In order to control residual stress distribution in glass, techniques based on the phenomenon of photoelasticity are efficient, though subject to the inherent limitations of all optical techniques. To mitigate these limitations, we exploit the phenomenon of acoustoelasticity to estimate residual stress distribution, using surface acoustic waves. In this study, we characterize the surface residu...

This paper presents a numerical and experimental study of capillary wave motion excited by high frequency surface acoustic waves SAWs . The objective of this study is to provide insight into the dynamic behavior of the fluid free surface and its dependence on the excitation amplitude. A two-dimensional numerical model that couples the motion of the piezoelectric substrate to a thin liquid layer...