Good industrial large scale practice

Gold wire, 12 692, 702 77 833 Golf clubs, titanium in, 24 868 Goniometer, 26 420, 423 Goniospectrophotometers, 7 325 Gonorrhea vaccine, 25 499-500 Good (Industrial) Large Scale Practice (G[I]LSP), 77 49... 

Note All but four of these industrial processes operate at GILSP (good industrial large-scale practice). 

Note Regarding Chemical Laboratory Hoods. Industrial hygiene assessment for powder subdivision within chemical laboratory hoods indicates that face velocities should not exceed 100 feet per minute (fpm) with the sash in the lowered position. Personnel exposures at or below 1.0 pg/m3 are achievable for both large-scale and small-scale subdivisions, provided that good work practices are adhered to. When face velocities are maintained between 80 and 100 fpm and the sash is in a lowered position, work practices affect personnel exposure concentration by greater than one order of magnitude. Face velocities above 150 fpm result in excessive turbulence and an inability to weigh accurately, due to air movement, vibration and product loss to exhaust. 

Various vinyl polymers 1 are manufactured on a large scale, whereas practically no polyacetylenes 2 are produced by the industries. One of the reasons is that it was difficult to synthesize high polymers from acetylenes in good yields. However, the synthesis of high-molecular-weight polyacetylenes is currently becoming feasible. 

The study of gas transport in membranes has been actively pursued for over 100 years. This extensive research resulted in the development of good theories on single gas transport in polymers and other membranes. The practical use of membranes to separate gas mixtures is, however, much more recent. One well-known application has been the separation of uranium isotopes for nuclear weapon production. With few exceptions, no new, large scale applications were introduced until the late 1970 s when polymer membranes were developed of sufficient permeability and selectivity to enable their economical industrial use. Since this development is so recent, gas separations by membranes are still less well-known and their use less widespread than other membrane applications such as reverse osmosis, ultrafiltration and microfiltration. In excellent reviews on gas transport in polymers as recent as 1983, no mention was made of the important developments of the last few years. For this reason, this chapter will concentrate on the more recent aspects of gas separation by membranes. Naturally, many of the examples cited will be from our own experience, but the general underlying principles are applicable to many membrane based gas separating systems. 

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