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Coating operations definition

Decortication and Separation of Fibers.—By decortication is meant the removal of a coat and since in the preparation of vegetable fibers the cortex must be removed at some stage of the operation, this term has taken on the additional definition of mechanically cleaning fibers. [Pg.268]

Whiie many different GC coiumns could be used, a giass WCOT coiumn (25 m x 0.3 mm), coated with OV-1 and operated isothermaiiy at 240 C, gave satisfactory resuits in the work cited the TMS ether derivatives of epicoprostanoi and choiesteroi eiuted in 17.7 and 20 min respectiveiy [214]. Of course, the procedure must be caiibrated carefuiiy with suitabie standards, and the originai pubiication shouid be consuited for the fine detaii of the protocoi. Other workers have obtained resuits adequate for many purposes with packed coiumns (1.5 to 2 m x 4 mm i.d.) and simiiar non-poiar siiicone phases (e.g. 3% SE-30 reiative to the support), in routine use, a coefficient of variation of 0.35 to 0.5% was obtained. Even higher accuracy is ciaimed for "definitive" procedures in which [3,4- C]-choiesteroi [273,703] and deuterated choiesteroi [187,983] are empioyed as internai standards and GC-MS is used for quantification. [Pg.159]

In the second case, the precipitate which degrades the transparency of the liquid remains initially in suspension throughout the mass, but floats up then with an extreme slowness, and, after a few days, forms a definitely separate layer in the upper part of the liquid one then collects the limpid portion by means of a siphon which starts by a side tube, and the preparation is finished. I must point out that when one introduces into the liquid the short branch of the siphon, a portion of the precipitate forms around the external surface of the tube a kind of reversed cone it is thus necessary, before starting the siphoning, to remove this coating. For that, one initially leaves the whole at rest for a quarter hour, then one agitates a little from side to side the immersed branch of the siphon the cone of precipitate is detached as small blobs which float up little by little and will join the upper layer. The liquid collected under these conditions is much better than the preceding one can employ it in experiments at once after the operation of the siphon the test bubbles which it provides have a maximum three hours of persistence finally it is preserved sufficiently well for about a year. [Pg.74]

The selected process will produce a raw molded part that may or may not require surface preparation prior to coating. The surface finish may be limited by the inherent capabilities of the process. In general, higher pressure processes can produce better surface definition than processes that operate at low pressures. Push and squeeze type processes can often produce excellent surface definition and are capable of generating Class A surfaces or detailed grains out of the mold. [Pg.62]


See other pages where Coating operations definition is mentioned: [Pg.119]    [Pg.7]    [Pg.200]    [Pg.370]    [Pg.462]    [Pg.193]    [Pg.325]    [Pg.464]    [Pg.320]    [Pg.139]    [Pg.80]    [Pg.416]    [Pg.108]    [Pg.476]    [Pg.692]    [Pg.239]    [Pg.306]    [Pg.134]    [Pg.280]    [Pg.452]    [Pg.294]    [Pg.327]    [Pg.351]    [Pg.306]    [Pg.118]    [Pg.69]    [Pg.335]    [Pg.62]    [Pg.1369]    [Pg.24]    [Pg.281]    [Pg.539]    [Pg.100]    [Pg.1909]    [Pg.2602]    [Pg.74]    [Pg.256]    [Pg.28]    [Pg.106]    [Pg.254]    [Pg.603]    [Pg.570]    [Pg.43]    [Pg.224]    [Pg.102]    [Pg.103]   
See also in sourсe #XX -- [ Pg.342 ]




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