Disintegration limits

Keywords Contact angle Corona splashes Disintegration Disintegration limits Droplet impact Drop surface energy Heat transfer regimes Leidenfrost point Molten metal droplet impact Rupture Secondary atomization Spread Surface topography Thermal induced atomization Wettability... 

Given that impacting droplets may disintegrate by diverse mechanisms, secondary droplets are thus generated with dissimilar characteristics. Research efforts have also been put on the development of empirical sub-models to predict the size, velocity and number of secondary droplets. There are relatively few models valid for impacts raito diy surfaces. This must be taken into account, since major limitations to the use of these sub-models lies in the inaccurate consideration of the disintegration limits and in disregarding the boundary conditions for which they were validated. 

S. Moita, A. L. N. Moreira Drop impacts onto cold and heated rigid surfaces Morphological comparisons, disintegration limits and secondary atomization, Int. J. Heat Fluid Flow, 28(4), 735-752(2007). 

Esposito, G., Fmnzo, L., Panico, A., d Antonio, G., 2008. Mathematical modelling of disintegration-limited co-digestion of OFMSW and sewage sludge. Water Science and Technology 58 (7), 1513-1519. 

In a way, the limit set is thus the entire funnel between the two extreme cases qlc, and g o, Fig. 5. This effect is called Takens-chaos, [21, 5, 7]. As a consequence of this theorem each momentum uncertainty effects a kind of disintegration" process at the crossing. Thus, one can reasonably expect to reproduce the true excitation process by using QCMD trajectory bundles for sampling the funnel. To realize this idea, we have to study the full quantum solution and compare it to suitable QCMD trajectory bundles. 

Fig. 3.5 Potential vs. pH diagram for the CdTe-H20 system at 25 °C. Solid CdTe is thermodynamically stable over the entire pH range. Consequently, CdTe does not hydrolyze at any H and OH activities of practical interest. In acidic solutions, the only process accompanying cathodic CdTe polarization is hydrogen release. Therefore, in the region of cathode potentials, CdTe is a sufficiently stable electrode material from the electrochemical point of view. The -1.35 V potential is the lowest limit of stabihty. Below this limit, CdTe corrodes in the whole pH range e.g., for pH < 2.8, H2Te vapor is produced at -1.25 V. For pH > 2.8, diteUuride or telluride ions are formed with disintegration of the compound. (With kind permission from Springer Science+Business Media [82])...

The rate of disintegration of the dosage form and the size of the resulting aggregates can be the rate-limiting... 

Although untreated starches do not swell sufficiently, certain modified forms, such as sodium starch glycolate, do swell in cold water and are better as disintegrants. Various cellulose derivatives, including methylcellulose and carboxymethylcellulose, have been used in this role, but with limited success due to the marked increase in viscosity they produce around the dispersing tablet mass. 

Determination of the time for a tablet to disintegrate when immersed in some test fluid has been a requirement in most compendia for many years. For many years, it was the only test available to evaluate the release of medicaments from a dosage unit. We now recognize the severe limitations of such tests in assessing this property—hence, the introduction of dissolution rate requirements. 

There are two general types of optimization problem constrained and unconstrained. Constraints are restrictions placed on the system by physical limitations or perhaps by simple practicality (e.g., economic considerations). In unconstrained optimization problems there are no restrictions. For a given pharmaceutical system one might wish to make the hardest tablet possible. The constrained problem, on the other hand, would be stated make the hardest tablet possible, but it must disintegrate in less than 15 minutes. 

Fig. 13 Contour plots for (a) disintegration time (b) tablet hardness (c) dissolution response (%) (d) tablet friability as a function of disintegrant level and compressional force. Dashed lines on ordinate denote limits of experimental range (—1.547 to + 1.547 eu see text for details).

All chemistry is limited by the abundance of the elements, restricted to 90 in total (two of the natural 92 have disintegrated completely). The properties of the elements are correlated in fixed Groups and Periods of the Periodic Table. 

When the core of a massive star exceeds the Chandrasekhar limit, it collapses and energy is absorbed by photo-disintegration of 4He through the reaction... 

---