Aim at the random problems of flying gangue movement in steeply dipping seam mining, based on the spherical flying gangue movement model, computational formula of collision restitution coefficient was established when flying gangue shocks bottom plate of working face according to the theory of Hertz classical elastic collision; Considering the influences of the randomness such as the density, r...

I used Continuity, a tool for finite element analysis, to model isotropic propagation of electrical activity based on the monodomain equation. I was able to induce action potential duration (APD) alternans, an important potential precursor to atrial fibrillation, and found that modulating several variables to mimic isoproterenol administration increased the slope of the restitution curve at low...

The effect of friction in the thermal convection instability of granular fluids is studied by means of molecular dynamics simulations. It is found that the transitions between different convective states (zero, one, and two rolls) are primarily governed by the average energy loss per collisions and not by the friction and restitution coefficients separately, and can be roughly described in term...

We report numerical simulations of strongly vibrated granular materials designed to mimic recent experiments performed in both the presence and the absence of gravity. The coefficient of restitution used here depends on the impact velocity by taking into account both the viscoelastic and plastic deformations of particles, occurring at low and high velocities, respectively. We show that this mod...

We investigate the free cooling of inelastic rough spheres in the presence of Coulomb friction. Depending on the coefficients of normal restitution ǫ and Coulomb friction μ, we find qualitatively different asymptotic states. For nearly complete normal restitution (ǫ close to 1) and large μ, friction does not change the cooling properties qualitatively compared to a constant coefficient of tange...

Most descriptions of collision events introduce coefficients friction and tangential restitution which vary significantly with the impact angle, in contrast independence normal coefficient this parameter. A redefinition based on idea that effects can be treated as being mutually independent, provides a satisfactory description experimental data using ‘constant’ independent angle. This friction-...

We revisit our recent contribution [2] and give two simpler proofs of the socalled Haff’s law for granular gases (with non-necessarily constant restitution coefficient). The first proof is based upon the use of entropy and asserts that Haff’s law holds whenever the initial datum is of finite entropy. The second proof uses only the moments of the solutions and holds in some weakly inelasticity r...

Restitution, the characteristic shortening of action potential duration (APD) with increased heart rate, has been studied extensively because of its purported link to the onset of fibrillation. Restitution is often represented in the form of mapping models where APD is a function of previous diastolic intervals (DIs) and/or APDs, A(n+1)=F(D(n),A(n),D(n-1),A(n-1),...), where A(n+1) is the APD fo...

We develop in this paper the first systematic treatment of the homogeneous Boltzmann equation for granular gases with non constant restitution coefficient, generalizing a large number of the results obtained recently for homogeneous granular gases with constant restitution coefficient to a broader class of physical restitution coefficients that depend on the collision impact velocity. Our analy...

Upper bounds on Newton’s, Poisson’s, and energetic coefficients of normal restitution for the frictional impact of rigid pendulum against a fixed surface are derived, demonstrating that the upper bound on Newton’s coefficient is smaller than 1, while the upper bound on Poisson’s coefficient is greater than 1. The upper bound on the energetic coefficient of restitution, which is a geometric mean...