Grain packing

Texture Grain size Sorting Grain slope Grain packing Grain roundness Mineral composition... 

TNT, which was melted from WW1 ammunition into wooden boxes to be stored for more than 20 years at the bottom of the Delaware river. This TNT was remelted, grained, packed into Nutsches and purified by extraction with xylene, the only solvent... 

The framework grains in sandstones cemented by microcrystalline and coarse to poikilotopic calcite display a loose grain packing even when their replacement by carbonates is considered. Evidence... 

Liu YX, Heaney DF, German RM (1995) Gravity-induced solid grain packing during Uquid-phase sintering. Acta MetaU Mater 43 1587-1592... 

Diffusion coefficients for porous media are generally referred to as effective diffusivities, since the actual molecular diffusion process occurs in the fluid phase and interactions with the porous medium inhibits the chemical movement. There are both physical and chemical factors that go into estimating effective diffusivities. The physical effects are twofold. First, some fraction of the porous media is solid, limiting the volume through which fluid phase diffusion can occur. This is quantified by the porosity, which is defined as the ratio of the volume of void space to the total volume. Second, the connectivity between pore spaces in soil and sediment grain packs (as well as other porous media) are circuitous and lengthen the distance a molecule must travel to traverse the material. This lengthening of the diffusion path is quantified... 

---