Metal packings, characteristics

R.M. German, Particle Packing Characteristics, Metal Powder Industries Federation, New York, 1989, p. 120. 

German RM (1989) Particle packing characteristics. Metal Powder Industries Federation, Princeton... 

For three types of microstructured devices - the multichannel catalytic wall microreactor, the micro packed bed, and the catalytic metallic foam - the mass transfer effectiveness was calculated with the relations for mass transfer and pressure loss given in the previous sections. For the metallic foam, characteristic data were taken from [46] and [48]. The effectiveness is not dependent on the size or length of the device. 

Although a liquid metal can be considered to be a random assembly of ions, the fact that the density of such a metal changes little upon melting implies that the packing characteristics of the solid survive into the liquid, and impose a mean nonuniform short-range distribution on the liquid. This distribution can be described, for a pure liquid metal, in terms of the mean number, n(r) dV, of ions to be found in volume element dV at r, given that an ion also resides at r = 0. The pair distribution function, g(r), is then given by... 

G.C. Brown and others, Unit Operations, John Wiley Sons, New York, 1950, p. 210-16. R.M. German, Particle Packing Characteristics, Metal Powder Industries Federation, Princeton, New Jersey, 1989. 

German, R. M. Particle Packing Characteristics Metal Powder Industries Federation New York, NY, 1989 pp 23-308. 

Transition metal ions characteristically form coordination compounds, which are usually colored and often paramagnetic. A coordination compound typically consists of a complex ion, a transition metal ion with its attached ligands (see Section 15.8), and counterions, anions or cations as needed to produce a compound with no net charge. The substance [Co(NH3)5Cl]Cl2 is a typical coordination compound. The brackets indicate the composition of the complex ion, in this case Co(NH3)5Cl, and the two d counterions are shown outside the brackets. Note that in this compound one Cl acts as a ligand along with the five NH3 molecules. In the solid state this compound consists of the large Co(NH3)5Cl cations and twice as many Cl anions, all packed together as efficiently as possible. When dissolved in water, the solid behaves like any ionic solid the cations and anions are assnmed to separate and move about independently ... 

A summary of physical and chemical constants for beryUium is compUed ia Table 1 (3—7). One of the more important characteristics of beryUium is its pronounced anisotropy resulting from the close-packed hexagonal crystal stmcture. This factor must be considered for any property that is known or suspected to be stmcture sensitive. As an example, the thermal expansion coefficient at 273 K of siagle-crystal beryUium was measured (8) as 10.6 x 10 paraUel to the i -axis and 7.7 x 10 paraUel to the i -axis. The actual expansion of polycrystalline metal then becomes a function of the degree of preferred orientation present and the direction of measurement ia wrought beryUium. 

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