Ring-type laminations

C, and then three molecular equivalents of acetyl chloride and triethy-lamine were added. Three types of acetylated materials, 11, 12, and 13, were isolated accompanied by a small amount of thioketone 7 and thioamide 9 (Scheme 8 and Table 6). All of the acetylated materials showed optical activity. For the reaction of 6a, 84% ee of 2-(acetylthio)aziridine 11a, 50% ee of 4-(acetyl-thio)oxazoline 12a, and 20% ee of 4-(acetylthio)oxazolidin-2-one 13a were obtained in 39,10, and 16% yields, respectively. In the reaction of 6b,c, the corresponding optically active materials 11-13 were obtained as shown in Table 9. The formation of oxazoline 12 involves the rearrangement ofAT-acyl aziridines, which occurs by intramolecular attack of the carbonyl oxygen at the ring carbon to cause rupture of the system. 

Reduction o/ artnes, Raney nickel (Mozingo type) in combination with 2-propanol (reflux) effects reduction of aromatic rings in 2-18 hours, Naphthalene is reduced in 18 hours to tetralin (90% yield) and cu> and trurtv-decalin (10% yield). Anisole is reduced in 110 hours to cyclohexy) methyl ether (90% yield). Nitrobenzene is reduced quickly to aniline and then further to cydohexylamine and cydohexylisopropy lamine. 

The intervertebral disc contains two distinct regions, the nucleus pulpo-sus and the annulus fibrosus. The nucleus occupies about 50% of the volume of the disc, and contains mostly water and small amounts of randomly oriented collagen fibers, cells and non-collagenous proteins [19]. The annulus is a tough ring-like structure that surrounds the nucleus. Highly oriented collagen fibers (primarily Types I and II) form a laminate structure in the annulus, with approximately 20-25 laminae oriented alternately at... 

Laminated disk-ring coupling (high speed spacer type)... 

There are two types of induction motor rotor - the wound rotor and the cage rotor. The cage rotor consists of a laminated cylinder of silicon steel with copper or aluminium bars slotted into holes around the circumference and short-circuited at each end of the cylinder, as shown in Fig. 3.23. In small motors the rotor is cast in aluminium. Better starting and quieter running are achieved if the bars are slightly skewed. This type of rotor is extremely robust and since there are no external connections there is no need for slip rings or brushes. A machine... 

Thermosetting polyimides are commercially available as uncured resins, thin sheets, and laminates. Thermoplastic polyimides are very often called pseudothermoplastic. There are two general types of polyimides. One type is linear polyimides which are made by combining imides into long chains. Aromatic heterocyclic polyimides are the other usual kind, where R and R" are two carbon atoms of an aromatic ring. Examples of polyimide films include Apical, Kapton, and Kaptrex. Polyimide parts and shapes include Meldin, Vespel, and Plavis. Polyimides have been in mass production since 1955. 

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