A Measure of the Departure from Randomness

but certainly not least, we need to define a parameter that measures the deviation from random statistics. This is given the symbol %, not to be confused with the Flory-Huggins interaction parameter % (Chapter II). The x we will use here is defined in Equation 6-45  

Now let s break this up into runs of segments of the same type by inserting spaces  

You can see that this chain of 20 units is arranged in 12 alternating runs and the run number, R, is then 12/20 (note that in general the chain has to be long enough that end effects can be ignored). Also note that every run of A units is terminated by an AB link and every run of B units is terminated by a BA link. Thus R is defined in Equations 6-43  

This gives us the following useful relationships (Equations 6-44)  

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We can express % (a measure of the departure from randomness) and the other parameters we have defined in terms of both conditional probabilities and then reactivity ratios and molar feed ratios. For example, % is given by Equation 6-53 ... 

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