Crystallization velocities

Mp 77°, d 1.56g/ccat 78.2°. The ref states that its crystallization velocity was small, permitting cast loaded charges to be obtained practically without cavities... 

Table 1-6 Effect of Temperature on Linear Crystallization Velocity of Water...

Figure 3. Effect of Invert Sugar on Crystallization Velocity...

Figure 4. Effect of Raffinose on Crystallization Velocity of Sucrose...

A crystal moving in this liquid, if its density is different from that of the liquid, has an additional vertical component of velocity Vg. There is no horizontal component due to gravity. The components of crystal velocity can be written in polar and in Cartesian coordinates as follows ... 

Measurements of crystallization velocity fall into two general classes those in which free dendrite growth is measured and those which confine the growing ice in a tube which is placed in a bath of some other liquid. The first has the prime advantage of eliminating any substrate effects but the estimation of the interface... 

TABLE 21.3 Crystallization Velocities and Viscosities of Glass-Forming Liquids ... 

An increase in temperature leads to a decrease in crystallization time because the solubility of the aluminosilicate hydrogel is enhanced at higher temperatures. Thus, the aging is accelerated, incubation period shortened, and crystallization velocity increased. The latter increases steadily with time and drops after a relatively high crystallization degree has been obtained. The reaction is commonly monitored by means of x-ray powder diffraction and is stopped at this point [104,110,137]. 

Figure 16.3 shows the evolution of the weight cr5 stalllnities of the two sets of crystallites at 3 different crystallization temperatures. As shown by Ruland [20], such reflection integrals that are complete in reciprocal space are proportional to the weight crystallinity of the perfect crystallites that produce the reflections. Latency periods between the quench and the start of the crystallization, as well as crystallization velocities of the two kind of crystallites, can be extracted from these data. Finally, conclusions concerning the crystallization mechanisms can be drawn [18]. 

Crystallization velocity expressed as time necessary for the formation of one seed in sec. 

Fig. 0.7. Crystallization of water in ice cream (according to Levine and Slade, 1990). v crystallization velocity ...

LDPE and HDPE are referred to branched and linear polyethylene respectively. The low degree of branching results in high crystallinity (70-90%) compared to (40-60%) in the case of LDPE and a higher crystallization velocity. This increases polymer density (0.94-0.96 g/mL vs. 0.91-0.93 mL) and crystalline melting temperature (130-138 vs. 105-115°C). 

With these particles two binary mixtures, Ml (SI, LI) and M2 (S2, L2) were prepared with number ratios Ni = Nsi/Nli = 11 and N2 = 2.5, respectively, in the good, isorefractive solvent 2-ethylnaphthalene. These values have to be compared with those of the reference system with F = 0.83 0.3, N = 2.5 0.3, ns = 35 and nL = 55. While the second number ratio is identical to that of the reference system, the first one has been chosen to check up on the effect of the particle size distribution on the re-entry region. Due to the small amount of large particles this mixture is closely approximating a nearly monodisperse system while reducing the crystallization velocity reasonably well to allow for the measnrement of glassy dynamics. 

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