Assumed divergence ratio

In attempting to explain his measurements, Keenan eschewed the nominal divergence ratio, but chose instead the assumed divergence ratio , determined from the pressure ratio at which the nozzle efficiency reached its maximum value. Keenan did not detail the equations he used, but we will outline the type of approach possible. 

As a result of calculations presumably similar to those above, Keenan derives a set of assumed divergence ratios (Table A6.3). 

Table A8.3 Nominal and Keenan s assumed divergence ratio...

The technique of separation of variables, that is, the possibility of separating the spatial and temporal variables in the stress and strain fields, is particularly useful in the solution of dynamic viscoelastic problems. As a rule, this requires us to assume that the Poisson ratio is constant, a reasonable assumption in many cases. Alternatively, the divergence of the displacement vector must be constant. A particularly important case of application of the variables separation method, where the assumption concerning the constancy of the Poisson ratio is relaxed, occurs in those problems in which the boundary conditions or the forces of volume are... 

The experimental approach examines bilayers with a limited precision in depth z (8=a few nanometers) and in volume fraction < > (a few percent). It assumes that at least the central part of the analyzed profile ( >(z) describes only the internal interface between coexisting phases ([q and 2. This is not necessarily true when surface segregation regions, adjacent to both external interfaces, cannot be neglected as it is for very thin films. Related finite size effects are discussed in detail in Sect. 3.2 theoretical models and computer simulations expect that size effects modify the intrinsic profile internal interface. Therefore size effects may lead in principle to systematic errors [6] of binodal values determined for films which are very thin or are profiled at T—>TC (where the ratio D/w is also small due to the diverging w). 

Figure 2 A section across the East Pacific Rise in the South Pacific showing He in excess over that expected from the atmospheric He dissoived in sea water when scaied to the more common He. The difference between the dissolved isotopic ratio and atmospheric ratio is represented by <5 He in percentage difference. He is assumed to be primordial and indicates degassing of the mantle at the divergent plate boundaries featured as oceanic ridge systems. STNstation number of the sampling. (Reprinted with permission from Lupton and Craig 1981, copyright American Association for the Advancement of Science.)...

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