Size control

Based on the approaches proposed for batch crystallization— which employed cooling/evaporation rates to control supersaturation, and on the specifics of the batch precipitation process—the reactant addition rate was chosen as the controlling variable. 

The relation between the growth rate G and supersaturation ratio S may be conveniently expressed by means of the power-law equation, similar to Eq. (6.29) 

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Advantages of pan granulation are ease of granule size control, hardness of granule, and simplicity of pollution control. 

Bubble size control is achieved by controlling particle size distribution or by increasing gas velocity. The data as to whether internal baffles also lower bubble size are contradictory. (Internals are commonly used in fluidized beds for heat exchange, control of soflds hackmixing, and other purposes.)... 

In order to make an efficient Y202 Eu ", it is necessary to start with weU-purifted yttrium and europium oxides or a weU-purifted coprecipitated oxide. Very small amounts of impurity ions, particularly other rare-earth ions, decrease the efficiency of this phosphor. Ce " is one of the most troublesome ions because it competes for the uv absorption and should be present at no more than about one part per million. Once purified, if not already coprecipitated, the oxides are dissolved in hydrochloric or nitric acid and then precipitated with oxaflc acid. This precipitate is then calcined, and fired at around 800°C to decompose the oxalate and form the oxide. EinaHy the oxide is fired usually in air at temperatures of 1500—1550°C in order to produce a good crystal stmcture and an efficient phosphor. This phosphor does not need to be further processed but may be milled for particle size control and/or screened to remove agglomerates which later show up as dark specks in the coating. 

Sizing of the cmshed and ground product is a necessary step prior to any mineral processing operation, and in the production of a product having a specific size. Controlling the size of material fed to other equipment is important. AH equipment has an optimum size range of material that it can handle most efficiently. Size separation can be achieved either by screening (for coarser particles) or by classification (for fines) (see also Separation, size). 

N,]S2-diaHyltartardiamide (DATD) [58477-85-3] (37). The cross-linking of polymerized monomer with the comonomer is what controls the pore size of the gel polymer mesh. This level of pore size control makes polyacrylamide gel electrophoresis an effective analytical tool. 

In some crystalhzation apphcations it is desirable to increase the solids content of the shiny within the body above the natural consis-tencw, which is that developed by equilibrium cooling of the incoming feed solution to the final temperature. This can be done by withdrawing a stream of mother liquor from the baffle zone, thereby thickening the shiny within the growing zone of the crystallizer. This mother liquor is also available for removal of fine ciystals for size control of the product. 

The processing of diatomite is unique, since its particle-size control is effected by calcination treatments and air classification. 

To ensure consistency, the two critical areas for control specific to injection molding are shot size control and temperature control on the injection system, i.e., screw portion for the reciprocating screw machines, and both the screw and ram sections for the screw/ram machines. As mentioned previously, for temperature and cure control, the use of microprocessor controls has significantly improved the performance of injection molding machines, including control of the shot size. 

For size analyses of particles larger than Vte y, the geometric properties of uniformly constructed physical barriers such as sieves are commonly used. Though this technique of finished product size control dates back to at least 2500 BC when the Egyptians constructed woven cloth sieves for preparation of foodstuffs, it is only within the... 

Finch at (28), show three "stratifying polymerizers" rather than the design combinations described earlier by Ruffing et al (27). The reactors operate at inlet and outlet temperatures respectively of 120 to 135°C, 135 to 145°C, and 145 to 170 C. The first reactor effluent contains 18 to 20% polystyrene and a portion of this stream is recirculated back to the reactor inlet such that the inlet stream polystyrene concentration is as high as 13.5%. This recirculation is claimed to improve rubber phase particle size control and end use properties. 

Rao, J. P. Geckeler, K. E. (2011). Polymer nanoparticles Preparation techniques and size-control parameters. Fh ogress in Polymer Science, Vol. 36, 7, (July 2011), pp. (887-913), ISSN 0079-6700... 

Taking into account that the state of nanoparticles is thermodynamically unstable against an unlimited growth, the physicochemical processes allowing reversed micelles to lead to stable dispersions and to a size control of nanoparticles are ... 

Size controlled by relative importance, Maximum intensity at signal score of 4,0, Omit rare terms used fewer than 100,0 times List 10 top scores Show score indexes. 

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