The rst arrival quasi-P wave traveltime eld in an anisotropic elastic solid solves a rst order nonlinear partial diierential equation, the qP eikonal equation. Since the qP slowness surface is convex, the rst arrival traveltime along downward propagating rays solves the paraxial qP eikonal equation, an evolution equation in depth. A second order upwind nite diierence scheme solves this paraxial...

A series of vanadium-substituted Dawson-structure POM-type ionic liquids, [TEAPS]7P2W17VO62 and [TEAPS]9P2W15V3O62, bearing sulfo-group grafted ammonium (TEAPS) cations and Dawson-type polyoxoanions have been formed which are reversible-thermal-response type gels. These gel-type compounds exhibit a phase transition from a quasi-solid gel phase to an isotropic sol phase. What's more, this series...

The field equations derived from the low energy string effective action with a matter tensor describing a perfect fluid with a barotropic equation of state are solved iteratively using the long-wavelength approximation, i.e. the field equations are expanded by the number of spatial gradients. In the zero order, a quasi-isotropic solution is presented and compared with the general solution of th...

This study investigates the applicability of time reversal concept in modern acoustics to structural health monitoring. A time reversal method has been adapted to guided-wave propagation to improve the detectability of local defects in composite plate structures. Specifically, wavelet-based signal processing techniques have been developed to enhance the time reversibility of Lamb wave in thin c...

A distributed microstructure model is obtained by homogenization from an exact micro-model with continuous temperature and flux for heat diffusion through a periodically distributed highly-heterogeneous medium. This composite medium consists of two flow regions separated by a third region which forms the doubly-porous matrix structure. The homogenized system recognizes the multiple scale proces...

We solve the two-particle s-wave scattering for an ultracold-atom gas confined in a quasi-one-dimensional trapping potential which is periodically modulated. The interaction between the atoms is included via Fermi's pseudopotential. For a modulated isotropic transverse harmonic confinement, the atomic center of mass and relative degrees of freedom decouple and an exact solution is possible. The...

In the past years quasi-conformal mapping has been generally used to design broadband electromagnetic cloaks. However, this technique has some inherit practical limitations such as the lateral beam shift, rendering the device visible or difficult to hide a large object. In this work we circumvent these issues by using strict conformal mapping to build the first isotropic cloak. Microwave near-f...

It is shown that, for proper symmetry of the parent lattice, antiferromagnetic order can survive in two-dimensional liquid crystals and even isotropic liquids of pointlike particles, in contradiction to what common sense might suggest. We discuss the requirements for antiferromagnetic order in the absence of translational and/or orientational lattice order. One example is the honeycomb lattice,...

Quasi-two-dimensional decaying turbulence is studied in a flowing soap film by measuring the moments of the probability density function P„dv(r)... for the longitudinal velocity differences dv(r) on a scale r. As in three-dimensional ~3-D! turbulence, P becomes non-Gaussian with decreasing r. The third moment S3(r)[^„dv(r)... & is small and negative at small scales, but becomes positive at larg...

Turbulence with an associated turbulent magnetic field is common in astrophysical environments. The determination of the transport of charged particles both parallel and perpendicular to the mean magnetic field is of considerable interest. Quasi-linear analysis or direct numerical simulation can be used to find the effects of the turbulent magnetic field on the transport of charged particles. A...