The Percus-Yevick theory for monodisperse hard spheres gives very good results for the pressure and structure factor of the system in a whole range of densities that lie within the gas and liquid phases. However, the equation seems to lead to a very unacceptable result beyond that region. Namely, the Percus-Yevick theory predicts a smooth behavior of the pressure that diverges only when the vol...

Measurements of the low-shear viscosity eta(o) with a Zimm-Crothers viscometer for dispersions of colloidal hard spheres are reported as a function of volume fraction phi up to 0.56. Nonequilibrium theories based on solutions to the two-particle Smoluchoski equation or ideal mode coupling approximations do not capture the divergence. However, the nonhydrodynamic contribution to the relative vis...

It is commonly assumeda, 7,9 that the solution to the diffusion equation with point source, derived from the equivalent heat problem s , describes ion migration in the brain. We show both theoretically and experimentally that the above solution must be generalized for iontophoresis of ions which are confined to the extracellular space of the brain. We further show that K ÷ behaves anomalously a...

Assuming perfect collision efficiency, we demonstrate that turbulence can initiate and sustain the rapid growth of very small water droplets in air even when these droplets are too small to cluster, and even without having to take gravity and small-scale intermittency into account. This is because the range of local Stokes numbers of identical droplets in the turbulent flow field is broad enoug...

Recent studies show that volume fractions φ(J) at the jamming transition of frictionless hard spheres and disks are not uniquely determined but exist over a continuous range. Motivated by this observation, we numerically investigate the dependence of φ(J) on the initial configurations of the parent fluid equilibrated at a volume fraction φ(eq), before compressing to generate a jammed packing. W...

Abstract Porosity in aluminum alloys is a great concern to the casting and automotive industry. In this publication, porosity formation air-melted vacuum induction melted (VIM) was studied compared understand its effect on microstructure mechanical properties of Al-7Si alloys. were cast at 700°C 900°C muffle furnace VIM furnace. Microstructural results show that refined eutectic silicon with sa...

Available experimental investigations on the effect of the aggregate-paste ‘interfacial transition zone’ (ITZ) on mass transport properties of cement-based materials appear to be ambiguous. Whilst some studies have found a deleterious effect of the ITZ, results from others seem to suggest otherwise. In the present study, we examined the relative influences of ITZ and microcracking on the oxygen...

We link the thermodynamics of colloidal suspensions to the statistics of regular and random packings. Random close packing has defied a rigorous definition yet, in three dimensions, there is near universal agreement on the volume fraction at which it occurs. We conjecture that the common value of phi{rcp} approximately 0.64 arises from a divergence in the rate at which accessible states disappe...

Relationships between the high-temperature oxidation behavior and the composite architecture (shape, size, volume fraction, and orientation of the reinforcement phase) are proposed.

We study the properties of jammed packings of frictionless spheres over a wide range of volume fractions. There exists a crossover volume fraction which separates deeply jammed solids from marginally jammed solids. In deeply jammed solids, all the scalings presented in marginally jammed solids are replaced with remarkably different ones with potential independent exponents. Correspondingly, the...