Cooling Crystals, instability

Other methods to achieve bitartrate stability, rarely used in the North Coast, are addition of metatartaric acid, electrodialysis, reverse osmosis, and ion exchange. Concern with potential bitartrate instability varies from winery to winery. Some enologists prefer to keep the processing of wine to a minimum. They rely solely on cool fermentation and winter storage temperatures to precipitate excess bitartrates. They trust their customers will overlook any additional bitartrate crystals that precipitate out in bottled wines. 

Processing problems that result in poor optical properties include die lines, low cooling rates, melt fracture, and, for coextrusion, interfacial instabilities. Die lines, as discussed previously, are bothersome because they can reduce both mechanical and optical properties. The cooling rate has a significant effect on polymer crystallization. Because crystallinity in polymers generally reduces optical properties, cooling rates are often increased to improve film clarity. Melt fracture will usually have an effect similar to die lines with respect to optical properties. Any occurrence that creates texture on the film surface will reduce film transparency. Similarly, if the texture occurs at the boundary of two layers in a coextruded film, as happens with interfacial instabilities, the same reduction in optical properties will result. 

The linewidth Ay of a single-mode color-center laser is mainly determined by fluctuations of the optical path length in the cavity (Sect. 5.4). Besides the contribution Av caused by mechanical instabilities of the resonator, temperature fluctuations in the crystal, caused by pump power variations or by temperature variations of the cooling system, further increase the linewidth by adding contributions Avp and Avt. Since all three contributions are indepen-... 

The thermostability of the y-modification of the present ani-PP is in sharp contrast with the thermal instability of the previously reported Y-form. The effect of heating rate on the melting endotherm and the effect of cooling rate on the crystallization exotherm were... 

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