Formulation process hquid forms

For incompressible fluid V v = 0, e = s and rheological equation can be formulated in the form of the x- dependence from e. Compressibility of the hquid must be accounted for in fast dynamic processes such as acoustic waves propagation, etc. For compressible medium the dependence of pressme, p, on the density, p, and the temperature, T, should be specified by equation, p = pO. T), that is usually called the equation of state. 

Other test media and techniques include post-emulsification penetrants, penetrants that form gels resistant to easy removal from entrapments, penetrants that concentrate dye constituents as their carrier Hquids evaporate during test processing, and penetrants that form strippable coatings in the developers. StiU other penetrant systems are formulated for use at abnormally low or high temperatures for special test appHcations. 

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