Bulk filling operation

They can be used alone with lime for low-cost bulk filling operations such as backfilling in old mine workings or to extend and improve the properties of Portland cement. Their use reduces permeability and heat of hydration, leading to improved durability. The downside is that strength development is slower. Analysis is important to discover the likely reactivity of the pozzolan and to determine whether it contains anything likely to be deleterious to its intended use. 

The time limit for completing the compounding and filling operation for (product name) USP is 24 hours (from bulk solution q.s. to end of filtration). 

Assay methods for monitoring any degradation products may be used to justify the time limits for bulk storage. This time would include the period from when the product is formulated to the end of the filling operation. Because most lyophilized formulations do not contain a biological preservative, microbiological quality before sterilization by filtration must also be monitored. The unfiltered solution bioburden would include microorganisms and endotoxin levels. 

An example of an uninterrupted filling operation cycle is one shift s production using the same personnel, equipment, and batch of bulk gas. 

Metals and alloys, the principal industrial metalhc catalysts, are found in periodic group TII, which are transition elements with almost-completed 3d, 4d, and 5d electronic orbits. According to theory, electrons from adsorbed molecules can fill the vacancies in the incomplete shells and thus make a chemical bond. What happens subsequently depends on the operating conditions. Platinum, palladium, and nickel form both hydrides and oxides they are effective in hydrogenation (vegetable oils) and oxidation (ammonia or sulfur dioxide). Alloys do not always have catalytic properties intermediate between those of the component metals, since the surface condition may be different from the bulk and catalysis is a function of the surface condition. Addition of some rhenium to Pt/AlgO permits the use of lower temperatures and slows the deactivation rate. The mechanism of catalysis by alloys is still controversial in many instances. 

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