Aggregates Aging

The importance of aggregate "aging" to condition the aggregates to resist breakup during shear encountered in pumps and centrifuges is documented (24-25). The influence of preparation conditions on... 

In summary, the typical final restructured value A 2.0-2.2 for laboratory results may be compared with a value Df l.2 for simulations [72, 113], In this model, diffusion-limited cluster-cluster aggregates restructured in discrete steps to A 2.2, after which further increase was not possible. The situation in the atmosphere is more complex, and there probably exists a spectrum of A values in the range 1.8 to 2.0-2.2, dependent mainly on aggregate age and meteorological conditions encountered. 

This untimely polymer formation is understood to be caused by the very rapid hydrolysis and aggregation of monomeric Pu(IV) species (at the region of condensate reentry into the hot plutonium solution) to produce hydrous polymers that are not readily depolymerized. At high temperatures such as found under reflux conditions, the polymer rapidly ages through the conversion of hydroxyl- to oxo-bridges ... 

Fatal infantile cytochrome c oxidase (CCO) deficiency is characterized by total absence of catalytic activity in skeletal muscle. This often occurs within the context of the Fanconi syndrome, or less commonly in association with a cardiomyopathy. Although the deficiency is global in skeletal muscle, with all fibers affected, only isolated scattered fibers show abnormal aggregations of mitochondria (ragged-red fibers). Multiple affected siblings within one family are frequently encountered and suggest autosomal recessive inheritance. The condition normally proves fatal before the age of six months and is characterized by worsening intractable lactic acidemia. 

Figure 1.8 6Li NMR of Li aggregate after aging at higher temperature.

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