We investigate, at a laboratory scale, the collapse of cylindrical shells of radius R and thickness t induced by a granular discharge. We measure the critical filling height for which the structure fails upon discharge. We observe that the silos sustain filling heights significantly above an estimation obtained by coupling standard shell-buckling and granular stress distribution theories. Two e...

We develop an approach for computing the hydrodynamic friction tensor and scalar friction coefficient for an aerosol fractal aggregate in the transition regime. Our approach involves solving the Bhatnagar-Gross-Krook equation for the velocity field around a sphere and using the velocity field to calculate the force on each primary sphere in the aggregate due to the presence of the other spheres...

In this paper, the mass transfer in a time varying thin liquid film over a stretching heated plate having variable temperature and concentration is analyzed. The analytical solution for the unsteady NavierStokes, energy and diffusion equations are obtained. A new similarity is found using group-theoretic analysis which renders the exact similar governing equations amenable to analytical solutio...

It has been pointed out that a chaos control technique wherein a weak excitation is added to the system could be useful for the control of friction at the nanoscale. We examine the claim that this technique can achieve chaos control even though the added excitation is weak. We show that this claim is only valid for the particular case of systems with very shallow potential wells. However, the a...

We study radiation convective fluid flow with chemical reaction. The dimensionless governing equations are solved using perturbation technique. The effects of velocity, temperature and concentration are studied for different parameters such as Grashof number, chemical reaction number, Prandtl number, Mass Grashof number and Radiative parameter. It is observed that the velocity increases with in...

A game-theoretic efficient market hypothesis says that a trading strategy will not multiply the capital it risks substantially relative to a specified market index. This implies that the autocorrelation of returns with respect to the index will be small and that a signal x will have approximately the same lead-lag effect on all traded securities. These predictions do not depend on assumptions a...

Two simple feedback control laws for drag reduction are derived by applying a suboptimal control theory to a turbulent channel flow. These new feedback control laws require pressure or shear-stress information only at the wall, and when applied to a turbulent channel flow at Reτ = 110, they result in 16–22% reduction in the skin-friction drag. More practical control laws requiring only the loca...

We show how to implement stick boundary conditions for a spherical colloid in a solvent that is coarse-grained by the method of stochastic rotation dynamics. This allows us to measure colloidal rotational velocity autocorrelation functions by direct computer simulation. We find quantitative agreement with Enskog theory for short times and with hydrodynamic modecoupling theory for longer times. ...

We study quantum effects on moduli dynamics arising from the production of particles which are light at points of enhanced symmetry in moduli space. The resulting forces trap the moduli at these points. Moduli trapping occurs in time-dependent quantum field theory, as well as in systems of moving D-branes, where it leads the branes to combine into stacks. Trapping also occurs in the presence of...

The classical experiments on turbulent friction in rough pipes were performed by Nikuradse in the 1930s. Seventy years later, they continue to defy theory. Here we model Nikuradse's experiments using the phenomenological theory of Kolmogórov, a theory that is widely thought to be applicable only to highly idealized flows. Our results include both the empirical scalings of Blasius and Strickler ...