Cooling filled composites

The air-coupled ultrasonic probes are essentially built up by the piezo-composite plate and a front side matching layer, made of air bubbles filled plastic materials. By using a thermoplastic material as matrix material of the composite, the transducer can easily be shaped by heating up, forming and cooling down to realize focusing transducers. Because of the low... 

In Bridgman growth [155], a boat or vessel filled with the melt is slowly cooled from one side, so that the crystal forms from that side. In Czochralski growth [156,157] a cylindrical crystal sits on the surface of the melt and is slowly pulled upward. In both cases the hydrodynamical flow of the melt is an important factor in the chemical composition and fine structure of the resulting crystal. 

If an aqueous solution of hydroqumone is cooled while under a pressure of several hundred kilopascals (equals several atmospheres) of a noble gas [X = Ar. Kr. Xe. a crystalline solid of approximate composition [C HjfOHLljX is obtained. These solids are 0-hydroquinone dathrates with noble gas atoms filling most of the cavities.5 Similar noble gas hydrates are known (Fig. 17 l). These clathmlcs are of some importance since they provide a stable, solid source of the noble gases. They have also been used to effect separations of the nohle gases since there is a certain selectivity exhibited by the cfctihnucs. 

The highest yields of monomers such as TFE, HFP and C-C4F8 of aronnd 90 wt% were obtained at pyrolysis temperatures of between 645 and 600° C. Formation of oligomeric PTFE waxes can be explained by repolymerization of TFE in the cooling steps where the steam is condensed. The same phenomena occnr dnring indnstrial production of TFE. Carbon black and glass fibres have nearly no inflnence on the prodnct composition (compare Table 24.9). For the bronze-filled PTFE the yields of TFE, HFP and C-C4F8 were... 

Mineralorganic material-filled thermoplast compositions are used in production of linoleum floor covering [12] sheets for filling cooling tower sprayers [79] technical casings, furniture fittings, etc. 

Figure 10 Comparison of Mg/Ca ratios measured in benthic foraminifera from a smoothed, composite record (thick solid curve Lear et al., 2000), and from site 747 (filled circles BiUups and Schrag, 2002). Both records display an overall trend of declining Mg/Ca ratio with decreasing age. This trend is indicative of cooling deep-water temperatures during the Cenozoic.

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