We tackle the numerical simulation of reaction-diffusion equations modeling multi-scale reaction waves. This type of problems induces peculiar difficulties and potentially large stiffness which stem from the broad spectrum of temporal scales in the nonlinear chemical source term as well as from the presence of large spatial gradients in the reaction fronts, spatially very localized. In this pap...

Copyright© 2001 by Gharib, Modarress, Fourguette, and Wilson. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. Abstract This manuscript describes two MEMS based optical sensors for wall shear stress and velocity measurements in flow fields. Experimental results obtained with the wall shear stress sensor, the MicroS3, are compared with boundary layer ve...

Recent study has shown that 3D computations of the morphological development of a coast shows irregularities compared with the 2DH (depth-averaged) computations. Therefore a validation of the surf zone currents computed using the 2DH (depth-averaged) and 3D approach in Delft3D is made. The 2DH and 3D approach are compared using an idealized case and validated using data from the laboratory expe...

Abstract. This paper investigates in detail a possible mechanism of energy convergence leading to freak waves. We give examples of a freak wave as a (weak) pseudo-maximal wave to illustrate the importance of phase coherence. Given a time signal at a certain position, we identify parts of the time signal with successive high amplitudes, so-called group events, that may lead to a freak wave using...

First arrivals of seismic waves were recorded along the Kamchatka arc using broadband seismic stations deployed for one year in 1998–1999. Cross correlation methods were used from a high resolution data set for tomographic inversion of body waves. The P-wave teleseismic tomography shows evidence of slab shoaling along the northern terminus of the Kamchatka subduction zone. Tomographic anomalies...

The new method for producing of the polarized relativistic positrons is suggested. A beam of unpolarized positrons accelerated up to a few GeV can be polarized during a head-on collision with an intense circularly polarized lazer wave. After a multiple Compton backscattering process the initial positrons may lose a substantial part of its energy and, as consequence, may acquire the significant ...

The modern study of ocean surface waves started with a pioneer study by Sverdrup and Munk (1947). More than half a century has passed since then and the study of ocean surface waves has greatly advanced. The current numerical wave models, supported by many fundamental studies, enable us to compute ocean surface waves on a global scale with sufficient accuracy for practical purposes. However, ph...

Void detection is challenging due to the complexity of near-surface materials and the limited resolution of geophysical methods. Although multichannel, high-frequency, surfacewave techniques can provide reliable S-wave velocities in different geological settings, they are not suitable for detecting voids directly based on anomalies of the S-wave velocity because of limitations on the resolution...

[1] The lowermost mantle beneath Central America has anisotropic seismic velocity structure manifested in shear wave splitting of signals from South American earthquakes recorded at North American broadband recording stations. Prior studies of deep mantle anisotropy in this region have characterized the structure as having vertical transverse isotropy (VTI), which is sufficient to explain a gen...