Expansion granulate

Exxon products appear to release via a unique mechanism. Like other polymer-coated technologies, the penetration of water iato the granule is purely by diffusion. However, as water enters the particle, an osmotic pressure is created as the fertilizer is solubilized. This pressure causes an expansion of the elastomeric coating and the particle swells to many times its original diameter. As the particle swells, the coating becomes increasingly thinner to the point where it caimot contain the internal pressure and the nutrient is released. 

Enzymes. Where tablets are not naturally very cohesive and have thus been manufactured by a wet granulation process involving one of the binders listed in Table 8, addition of small quantities of appropriate enzyme may be sufficient to produce rapid disintegration. It has also been proposed that disintegration action might result from expansion of the entrapped air due to generation of heat of wetting when the tablet is placed in a fluid. This concept has received little attention. 

Fluidized Bed Granulation The next evolution was to position a nozzle in the expansion chamber, to spray a water or binding medium downward into the dry fluidizing powders (figure 2). By... 

Fig. 2. Video micrograph of exocytosis in a goblet cell grown in tissue culture. Notice that the swelling of a secretory granule has been captured at 3 consecutive times (inset). The radial expansion of the exocytosed granules follows a typical first-order kinetics. The continuous line is a non-linear least square fitting to the data points to r(t) = rf — (rf — rj e " /T, where r, and rr are the initial and final radius of the granule, and t is the characteristic relaxation time of swelling...

During process development, samples at various stage of granulation should be obtained and analyzed. To maintain similar bed expansion throughout the whole granulation process, the superficial gas velocity should be increased based on granule properties. The amount of fluidization gas required for the bed expansion can be estimated from Eqs. (4.6)-(4.8). The inlet airflow was found to have little impact on granule size.37... 

By 23 DAP, cell division had ceased, as increase in endosperm volume was by cell expansion only. The pericarp had collapsed and the aleurone and subaleurone cell layers were fully differentiated. The outer layers of the starchy endosperm contained small, rounded granules embedded in cytosol, and the more central cells were filled with starch and had very little cytosol. 

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