Cooling Hindered

The disordered structure can be stabilized to room temperature by inclusion of substitutional impurities on the In sites. Thus the oxide formed when Ga is substituted for In, Ba2(ln1 xGaJt-)205+s to form Galn defects has a disordered cubic perovskite structure even at room temperature for values of x between 0.25 and 0.5, and the similar Ba2iln1 vCox)205+3 with Coin defects has a disordered cubic perovskite structure at room temperature when x lies between 0.2 and 0.8. The defects present in the In sites hinder oxygen ordering during the timescale over which the samples cool from the... 

The dissolved substances (especially if the solution is very concentrated) often crystallises in the funnel on account of local cooling and in this way filtration is hindered. This trouble can be partially met by using a funnel (Fig. 3) with the delivery tube cut short (0 5-l-0 cm.). But it is much more satisfactory to use a so-called hot water funnel (Fig. 4) in which the filtering surface of the funnel is heated with boiling water in a metal jacket. When inflammable solvents are used, the flame must be extinguished before filtration. 

Scott and co-workers [79] proposed a mechanism for CNT formation that involves the initial formation of a carbon cloud consisting of short carbon entities ( 3) and vaporized catalyst. Upon cooling, the condensation of the catalyst hinders the aggregation of carbon blocks into larger clusters, while supporting the anisotropic addition of carbon units into SWCNTs instead. The deposited SWCNTs are then collected from the cooled chamber walls after the synthesis. 

When cooled or contaminated, hindered phenolic antioxidants and some PDA antioxidants are known to precipitate from solution as concentrated compounds. At temperatures below 60°F (15.5°C), some antioxidants will begin to crystallize and drop from their solvent carrier as relatively pure materials. 

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