Folding units, early

Process plant design has come a long way from the early 1930s when process designers used the rule-of-thumb that a process faciUty could not be scaled-up more than 10-fold (2). American Oil s Ultracracking unit (Texas City, Texas) for example, was designed from data from a small pilot plant with a scale-up factor of 80,000 (3). 

The crystal polymorphism of the chiral but racemic P5MH1 is, to some extent, very reminiscent of that of isotactic polypropylene. It exists in two crystal modifications. One crystal modification is stable at high temperature, and was observed early on by Corradini et al [39]. Its structure has been redefined as a chiral, frustrated one based on a trigonal cell with three threefold helices per cell. We have also discovered a second crystal modification produced from solution. It has an orthorhombic unit cell that contains four chains in - again - three-fold helical conformation, for which one must assume coexistence of two right- and two left-handed helices. Contrary to the a and ft phases of iPP, the frustrated structure of poly( 5-methyl-hexene-1) is the more stable one [40]. 

Samples for the Rotofor need not be completely desalted before fractionation. Ions in the sample solution are electrophoresed into the two end compartments in the early stages of the run. Two percent (w/v) carrier ampholyte in the initial sample solution supplies enough ampholyte for refractionation of pooled material. After the tubes containing the protein of interest have been identified, they can be pooled for a second run. The pooled material need only be diluted enough (usually with water) to fill the separation chamber. The ampholytes in the pooled fractions cover pH ranges centered on the pis of the proteins of interest and are generally less than 1 pH unit. Thousand-fold purification has been achieved on refractionation. 

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