We study the formation of marginally trapped surfaces in the head-on collision of two shock waves in de Sitter space-time as a function of the cosmological constant and the energy of the shock wave. For D = 4 it is shown that there exists a critical value of the ratio of these quantities above which no solution to the trapped surface equation is found. For the ratio below the critical value the...

Although we rarely see a shock wave in everyday life, we experience them upon hearing the sound of an explosion, the bang of a gunshot, or the crack of a whip. In addition, objects that travel at supersonic speeds, such as bullets and missiles, also generate shock waves. During a typical shock-loading process, large pressures generated at the shock front can lead to an increase in the reactants...

This paper present a novel numerical algorithm for the linear one-dimensional heat and wave equation. In this method, a nite dierenceapproach had been used to discrete the time derivative while cubic spline isapplied as an interpolation function in the space dimension. We discuss theaccuracy of the method by expanding the equation based on Taylor series andminimize the error. The proposed metho...

skeletal muscle may develop adaptive chaperone and enhancementdefense system through daily exercisestimulation. the present study investigated resistance and exhaustion training alters the expression of chaperoneproteins. these proteins function to maintain homeostasis, facilitate repair from injury and provide protection. exercise-induced production of hsps in skeletal muscle and peripheral le...

bacterial and viral triggers are suspected agents in the initial etiology of autoimmune diseases. there are some studies on the etiology of autoimmune disorders which have focused on streptococcal infection and a possible relation with microbial heat shock proteins (hsp) which show significant homology with human heat shock proteins. in addition, some serotypes of streptococci cross-react with ...

We identify a new type of shock wave by constructing a stationary expansion shock solution of a class of regularized shallow-water equations that include the Benjamin-Bona-Mahony and Boussinesq equations. An expansion shock exhibits divergent characteristics, thereby contravening the classical Lax entropy condition. The persistence of the expansion shock in initial value problems is analysed an...

The 2D time dependent solution of thin accretion disk in a close binary system have been presented on the equatorial plane around the Schwarzschild black hole. To do that, the special part of the General Relativistic Hydrodynamical(GRH) equations are solved using High Resolution Shock Capturing (HRSC) schemes. The spiral shock waves on the accretion disk are modeled using perfect fluid equation...

We consider the structure of steady–state radiative shock waves propagating in the partially ionized hydrogen gas with density ρ1 = 10 −10 gm cm and temperature 3000 K ≤ T1 ≤ 8000 K. The radiative shock wave models with electron thermal conduction in the vicinity of the viscous jump are compared with pure radiative models. The threshold shock wave velocity above of which effects of electron the...

Our domain G = (0,L) is an interval of length L. The boundary ∂G = {0,L} are the two endpoints. We consider here as an example the case (DD) of Dirichlet boundary conditions: Dirichlet conditions at x = 0 and x = L. For other boundary conditions (NN), (DN), (ND) one can proceed similarly. In one dimension the Laplace operator is just the second derivative with respect to x: ∆u(x, t) = uxx(x, t)...