The diffusive-viscous wave equation plays an important role in seismic exploration and it can be used to explain the frequency-dependent reflections observed both in laboratory and field data. The numerical solution to this type of wave equation is needed in practical applications because it is difficult to obtain the analytical solution in complex media. Finite-difference method (FDM) is the m...

This article demonstrates the measurement of shear wave speed and shear speed dispersion of biomaterials using a chirp signal that launches waves over a range of frequencies. A biomaterial is vibrated by two vibration sources that generate shear waves inside the medium, which is scanned by an ultrasound imaging system. Doppler processing of the acquired signal produces an image of the square of...

Lagrangian GPS drifter experiments, carried out in the surface layer of stratified Lake Kinneret (Israel), are presented. Differential kinematic properties and Lagrangian statistics were calculated and used to estimate the dominant mechanisms for horizontal dispersion. On time scales smaller than a few internal wave periods, internal waves lead to strong divergence and convergence events, causi...

Numerical simulation of seismic waves is essential for understanding field observations and developing inversion schemes. The wavefields generated by the most popular numerical methods such as finite differences and finite elements are often contaminated with grid dispersion and edge reflections. We will present a grid dispersion and stability analysis based on a generalized eigenvalue formulat...

Epicardial activation and repolarisation sequences were investigated in patients with upright or inverted T waves in left ventricular leads of the surface electrocardiogram. Fifteen patients were studied: 10 were undergoing coronary artery bypass grafting (upright T waves) and five aortic valve replacement (four patients with T inversion). Monophasic action potentials were recorded intraoperati...

The dependence of the velocity surface acoustic waves (SAWs) as a function an external applied magnetic field is investigated in $\mathrm{Fe}$ thin film epitaxially grown on piezoelectric $\mathrm{Ga}\mathrm{As}$ substrate. SAW observed to strongly depend both amplitude and direction field. To interpret experimental data phenomenological approach relative change implemented. We find that variat...

The staggered-grid finite-difference (FD) method is widely used in numerical simulation of the wave equation. With stability conditions, grid dispersion often exists because of the discretization of the time and the spatial derivatives in thewave equation. Therefore, suppressing grid dispersion is a key problem for the staggered-grid FD schemes. To reduce the grid dispersion, the traditional me...

A number of existing models for surface wave phase speeds (linear and non-linear, breaking and non-breaking waves) are reviewed and tested against phase speed data from a large-scale laboratory experiment. The results of these tests are utilized in the context of assessing the potential improvement gained by incorporating wave non-linearity in phase speed based depth inversions. The analysis is...

We have studied the velocity dispersion of guided waves in transversely isotropic formations. Theoretical velocity dispersion curves were calculated with elastic constants based on laboratory and field measurements and compared to dispersion curves for isotropic formations having the same vertical po and S-wave velocities. The symmetry axis for the transverse isotropy was parallel to the boreho...

The paper presents the electromagnetic (EM) wave propagation in cylindrical optical fibers with helical windings under slowand fast-wave considerations. Field components are deduced for both the cases, and also, the dispersion relations are obtained by applying the boundary conditions, as modified by the presence of conducting helical windings. Two special cases are considered corresponding to ...