A reliable description of dense gas–solid two-phase flows of Geldart A particles in gasfluidized beds at life-size scale is of great practical importance in process industries. The classical two-fluid model, based on the kinetic theory of granular flows (KTGF), provides a very promising theoretical framework for predicting large-scale gas–solid twophase flows. However, thus far the two fluid mo...

a nonstandard finite difference (nsfd) scheme has been constructed and analyzed for a mathematical model that describes lotka–volterra food web model. this new discrete system has the same stability properties as the continuous model and,on the whole, it preservesthe same local asymptotic stability properties. linearized stability theory and schur–cohn criteria are used for local asymptoticstab...

The creation and manipulation of conceptual shapes need different modeling techniques from what are available in present CAD systems. Conceptual modeling techniques are supposed to provide more flexible interaction and mimic working with true materials. Therefore, this paper proposes a new computer internal modeling technique that supports the natural ways of exteriorizing shape concepts as wel...

Reduction of Single Input Single Output (SISO) discrete systems into lower order model, using a conventional and an evolutionary technique is presented in this paper. In the conventional technique, the mixed advantages of Modified Cauer Form (MCF) and differentiation are used. In this method the original discrete system is, first, converted into equivalent continuous system by applying bilinear...

In this paper we study stochastic models for the transport of particles in a uidized bed reactor, and compute the associated residence time distribution (RTD). Our main model is basically a diiusion process in 0; A] with reeecting/absorbing boundary conditions, modiied by allowing jumps to the origin as a result of transport of particles in the wake of rising uidization bubbles. We study discre...

We present "twin Higgs models," simple realizations of the Higgs boson as a pseudo Goldstone boson that protect the weak scale from radiative corrections up to scales of order 5-10 TeV. In the ultraviolet these theories have a discrete symmetry which interchanges each standard model particle with a corresponding particle which transforms under a twin or a mirror standard model gauge group. In a...