A theory of coherent X-ray radiation generated by a beam relativistic electrons in single crystal the direction close to electron-beam axis is developed Laue scattering geometry. The takes into account asymmetry electron-field reflection with respect surface and divergence. Expressions describing spectral-angular densities parametric near electron-velocity direction, transition radiation, their...

Volume conservation and shape preservation are two well-known issues related to the advection remeshing in front tracking. To address these issues, this paper proposes a divergence-preserving velocity interpolation method parabolic fit vertex positioning for operations three-dimensional Errors preserving divergence of field when interpolating from fluid mesh vertices triangles primary reason vo...

We present a class of discontinuous Galerkin methods for the incompressible Navier-Stokes equations yielding exactly divergence-free solutions. Exact incompressibility is achieved by using divergence-conforming velocity spaces for the approximation of the velocities. The resulting methods are locally conservative, energy-stable, and optimally convergent. We present a set of numerical tests that...

In this paper we investigate the use of divergence-free wavelet bases for the Coherent Vortex Extraction (CVE) of turbulent flows. We begin with a short presentation of the construction of 3D divergence-free biorthogonal wavelets. Then we apply the CVE decomposition to a homogeneous isotropic turbulent flow, computed by a direct numerical simulation at resolution 240 and upsampled to N = 256. A...

A lot of predictions for the statistical properties of the cosmic velocity field at large-scale have been obtained recently using perturbation theory. In this contribution I report the outcomes of a set of numerical tests that aim to check these results. Using Voronoi and Delaunay tessellations for defining the velocity field by interpolation between the particle velocities in numerical simulat...

Shallow-water equations discretized on a perfect hexagonal grid are analyzed using both a momentum formulation and a vorticity-divergence formulation. The vorticity-divergence formulation uses the unstaggered Z grid that places mass, vorticity, and divergence at the centers of the hexagons. The momentum formulation uses the staggered ZM grid that places mass at the centers of the hexagons and v...

refractor ambiguities are big problem in seismic refraction method especially in seismic engineering. there can be hidden subsurface geological phenomena such as hidden faults and shear zones which are not simply predicted by the travel-time graph or some geophysical methods. head wave amplitudes are used to show the resolution of refractor ambiguities and the existence of anisotropy in complex...

PURPOSE To examine gain, speed, and temporal characteristics of initial and closed-loop components of vergence eye movements in young and elderly subjects. METHODS Vergence eye movements in 13 elderly and 10 young adults were examined. A table with light-emitting diodes was used to elicit vergence starting from near (convergence, 40-20 cm; divergence, 20-40 cm) or from far (convergence, 150-4...