Length, comparison scale, macroscopic

Figure 11. Comparison of calculated macroscopic dispersivities (solid curve) to experimentally measured megascopic (laboratory scale) dispersivities. d is the grain diameter for the packing in the experimentSl measurements and the correlation length for the calculated curve. Better agreement could be obtained by letting d be about live times the correlation length in the calculated curve. (Reproduced from Ref. 4.)...

Several characteristic ratios of heterogeneity as functions of titanium particle size and sample porosity are shown in Figs. 75a and b, respectively. For the quasi-homogeneous approximation to be valid, the heterogeneity of the reactant medium should be small in comparison to the thermal length scale. As a result, the heterogeneity of the combustion front (shape and propagation) should also be small relative to the macroscopic behavior ... 

Most polysaccharides are macroscopically amorphous, but molecules of the linear polysaccharides of natural and artificial fibers, and stretched films are generally oriented parallel to one another, and appear partially or almost completely crystalline on X-ray crystallc raphic examination. Some unstretched linear molecules, amylose (in its complexes) for example, also exhibit partial crystallinity. In a number of cases the size of the unit cell of the crystal lattice has been evaluated. Comparison of the crystallographic data with scale models of short lengths of the polysaccharide chain has been used to reveal the manner in which inter- or intra-molecular hydrogen bonding hold the chains in the rigid framework of a crystal lattice. 

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