Neutral stability criteria

Based on the dispersion equation, the neutral stability conditions are derived by requiring a zero imaginary part for wave velocity C whereby the neutrally stable wave number, k, and the corresponding wave velocity, C, are obtained. The resulting neutral stability criteria reads ... 

The stabilizing influence of the surface viscosity of a typical monolayer was found to be negligible, in contrast to that of the surface elasticity, which (even for a so-called gaseous monolayer) was sufficient to cause a dramatic stabilization. The shift in the Pearson neutral-stability curves brought about by the presence of a gaseous monolayer and also by a close-packed monolayer on a 1-mm deep water substrate is shown in Fig. 16. For this example, the gaseous monolayer having a surface pressure of 0.2 dyn/cm effected a 500-fold increase in the stability criterion, whereas, in... 

Intrinsic thermal stability. This could be judged, for example on the basis of determinations of the rate of substrate consumption d[PH]/dt in a neutral atmosphere. According to this criterion, polyethylene, which begins to decompose at about 450° C, would appear more stable than... 

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