Affinity cuts

Properties of Coherent Systems Affinity Cuts, Composition Paths, and Composition Velocities... 

Coherence imposes stringent restrictions on the behavior of the species concentrations. Of the long list of required properties of coherent composition profiles only one which is rather striking will be mentioned, namely, the existence of affinity cuts. In a coherent composition profile, each location z at which concentration gradients exist has a so-called affinity cut. This cut divides the species, written in the sequence of decreasing affinity for the stationary phase, into two groups ... 

Recognizing the flexibility of the affinity laws, it is better to select an original pump impeller diameter that is somewhat larger than required for the range of anticipated performance, and then cut this diameter dowm after in-service tests to a slightly smaller diameter. This new performance can be predicted in advance. Once the impeller diameter is too small, it cannot be enlarged. The only solution is to order the required large impeller from the manufacturer. 

The accepted involvement of CpG methylation in transcription regulation has guided various lines of research into the direct effects methylation may have on chromatin structure. As early as 1982, Felsenfeld and co-workers looked for effects of DNA methylation on the affinity of DNA for histone octamers they reported a slight increase in this parameter [163]. Nightingale and Wolffe [164] using mononucleosome reconstitution on a specific sequence, the 5S rDNA from X. borealis, failed to see such an effect. More recently, Travers (personal communication) has seen clear-cut differences in the affinity of the histone octamer for a number of methylated versus unmethylated sequences. The fine structure of the core particle was, however, unaffected by the methylation status of the DNA [165]. 

The terms used to distinguish colloidal particles on the basis of their affinity to the fluid in which they are dispersed are lyophilic and lyophobic. These terms mean, literally, solvent loving and solvent fearing, respectively. When water is the medium or solvent, the terms hydrophilic or hydrophobic are often used. This terminology is very useful when considering surface activity such as wettability of a surface however, when used to classify colloids, the distinction is not always clear-cut. We consider these two types of colloids separately in the following subsections. 

When silver and steel are fused together, an alloy is formed which appears perfect while In fusion, hut globules of silver exude from it in cooling, which shows the weak affinity of the metals. At a very high tem-peratore the greater part of the silver volatilizes hut a portion, equal to about one in fivo hundred, remains, constituting a perfect alloy known as silver-steel, and which js admirably adapted to the formation of cutting instruments. 

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