1 Abstract In this paper we discuss the dynamical features of intermittent fluctuations in homogeneous shear flow turbulence. In this flow the energy cascade is strongly modified by the production of turbulent kinetic energy related to the presence of vortical structures induced by the shear. By using direct numerical simulations, we show that the refined Kolmogorov similarity is broken and a n...

A new mechanism of generation of large-scale magnetic fields in colliding protogalactic clouds and merging protostellar clouds is discussed. Interaction of the colliding clouds produces large-scale shear motions which are superimposed on small-scale turbulence. Generation of the large-scale magnetic field is due to a ”shear-current” effect (or ”vorticity-current” effect), and the mean vorticity...

Clustering is an important problem and has numerous applications. In this paper we consider an important clustering problem, called the k-center problem. We are given a discrete point set S and a constant integer k, and the goal is to compute a set of k center points to minimize the maximum distance from any point of S to its closest center. We consider both the discrete formulation, in which c...

This is a summary of ve lectures delivered at the CIME course on "Advanced Numerical Approximation of Nonlinear Hyperbolic Equations" held in Cetraro, Italy, on June 1997. Following the introductory lecture I | which provides a general overview of approximate solution to nonlinear conservation laws, the remaining lectures deal with the speciics of four complementing topics: Lecture II. Finite-d...

in this study, bimodal meso-porous silica (uvm-7) synthesized and fabricated amino silane modified supports were characterized by powder x-ray diffraction (xrd), n2 adsorption/desorption, transmission electron microscope (tem), elemental analysis and titration. capacity of co2 capture on modified bimodal pore structure silica at 70°c was calculated using breakthrough curves; and it was found th...

We examine mixed-layer deepening and the generation of internal waves in stratified fluid resulting from turbulence that develops in response to an applied surface stress. In laboratory experiments the stress is applied over the breadth of a finite-length tank by a moving roughened conveyor belt. The turbulence in the shear layer is characterized using particle image velocimetry to measure the ...

This paper is a continuation of earlier work [6] in which we presented an automatic domain decomposition method for the solution of gas dynamics problems which require a localized resolution of the kinetic scale. The basic idea is to couple the macroscopic hydrodynamics model and the microscopic kinetic model through a buffer zone in which both equations are solved. Discontinuities or sharp gra...

Basically the active power demands at various load buses need to be estimated ahead of time in order to plan the generation and distribution schedules, for contingency analysis and also for monitoring the system security. A great deal of attention has been given in recent years to the question of setting up the demand models for the individual appliances and their impact on the aggregated deman...

We present an efficient Monte Carlo method to simulate reaction–diffusion processes with spatially varying particle annihilation or transformation rates as it occurs for instance in the context of motor-driven intracellular transport. Like Green’s function reaction dynamics and first-passage time methods, our algorithm avoids small diffusive hops by propagating sufficiently distant particles in...