For systems showing non-Newtonian behaviour when measured in steady @S05676@, a @C01124@ \(\eta \) equal to \(\frac{\sigma}{D}\) at a given value of the @S05636@ \(D\), where \(\sigma \) is the stress; \(\eta _{0}\) is the limiting @V06627@ at zero @S05636@, and \(\eta _{\infty }\) the limiting @V06627@ at infinite @S05636@; \(\text{[}\eta _{0}\text{]}\) is the limit of @I03140@ at zero shear.