Large Stokes-shift ( approximately 4700 cm(-1)) four-wave mixing is generated in a deeply normal dispersion regime from a 20 cm commercial large-mode-area photonic crystal fiber pumped by amplified approximately 800 nm femtosecond pulses. The phase-matching condition is realized through an intermodal scheme involving two pump photons in the fundamental fiber mode and a pair of Stokesanti-Stokes...

We report results on dispersion relations and instabilities of traveling waves in excitable systems. Experiments employ solutions of the 1,4-cyclohexanedione Belousov–Zhabotinsky reaction confined to thin capillary tubeswhich create a pseudo-one-dimensional system. Theoretical analyses focus on a threevariable reaction–diffusion model that is known to reproduce qualitatively many of the experim...

Multiple earthquakes have been felt in high-rise buildings Bangkok despite the epicenters being far away. Seismic wave recordings basin show a low-frequency peak. This study uses horizontal-to-vertical spectral ratio (HVSR) analysis and array of ambient vibration data to find predominant period ground shear velocity profiles at five sites Bangkok. The accuracy accelerometer used for recording w...

It is well known that electron density profile in the geospace changes day by day and thus remote sensing techniques using electromagnetic waves are recently highlighted as a powerful tool, because they are useful for obtaining the global electron density profile in the earth’s plasmasphere with high time resolution. We have been developing tomographic techniques using information of propagatio...

The problem of propagation of plane wave including body and surface waves propagating in a transversely isotropic half-space with a depth-wise axis of material symmetry is investigated in details. Using the advantage of representation of displacement fields in terms of two complete scalar potential functions, the coupled equations of motion are uncoupled and reduced to two independent equations...

We report on the theoretical and experimental study of the generation of propagating waveguide modes on the water surface. These propagating modes are modulated in the transverse direction in a manner that satisfies boundary conditions on the walls of the water tank. It is shown that the propagating modes possess both anomalous and normal dispersion regimes, in contrast to the extensively studi...

Giant pulsations are nearly monochromatic ULF-pulsations of the Earth's magnetic ®eld with periods of about 100 s and amplitudes of up to 40 nT. For one such event ground-magnetic observations as well as simultaneous GEOS-2 magnetic and electric ®eld data and proton ̄ux measurements made in the geostationary orbit have been analysed. The observations of the electromagnetic ®eld indicate the exc...

A theoretical model, along with experimental verification, is developed to describe the generation, propagation and reception of a Rayleigh wave using angle beam wedge transducers. The Rayleigh wave generation process using an angle beam wedge transducer is analyzed, and the actual Rayleigh wave sound source distributions are evaluated numerically. Based on the reciprocity theorem and consideri...

In this work mass loading sensitivity of a Sezawa wave mode based surface acoustic wave (SAW) device is investigated through finite element method (FEM) simulation and the prospects of these devices to function as highly sensitive SAW sensors is reported. A ZnO/Si layered SAW resonator is considered for the simulation study. Initially the occurrence of Sezawa wave mode and displacement amplitud...