Understanding the behavior of sand-fines mixtures and assessing their shear strength or permeability require knowledge influence fine particles content on minimum void ratio. The latter is often evaluated using empirical methods models parameters without physical significance. Validated for both ordered disordered packings concrete mixtures, Theoretical Packing Density Model (TPDM) tested predi...

An accurate prediction of the minimum fluidization velocity is a crucial hydrodynamic aspect of the design of fluidized bed reactors. Common approaches for the prediction of the minimum fluidization velocities of binary-solid fluidized beds are first discussed here. The data of our own careful experimental investigation involving a binary-solid pair fluidized with water is presented. The effect...

Internal friction and void ratio will change among granular particles under vibration, and the size of void ratio directly affects strength of granular media. To further study the effect of vibration parameters on granular mechanical properties, discrete element method is used to simulate particles motion in a vibrating rectangular case by PFC2D software and study the influence of vibration fre...

We study the possible magnetization of cosmic voids by void galaxies. Recently, observations revealed isolated starforming galaxies within the voids. Furthermore, a major fraction of a voids volume is expected to be filled with magnetic fields of a minimum strength of about 10 −15 G on Mpc scales. We estimate the transport of magnetic energy by cosmic rays (CR) from the void galaxies into the v...

In this paper, we study the evolution of a relativistic, superhorizon-sized void embedded in a Friedmann-Robertson-Walker universe. We numerically solve the spherically symmetric general relativistic equations in comoving, synchronous coordinates. Initially, the fluid inside the void is taken to be homogeneous and nonexpanding. In a radiation-dominated universe, we find that radiation diffuses ...