shear dependent viscosity

For systems showing non-Newtonian behaviour when measured in steady simple shear, a coefficient $η$ equal to $σ D$ at a given value of the shear rate $D$ , where $σ$ is the stress; $η 0$ is the limiting viscosity at zero shear rate, and $η ∞$ the limiting viscosity at infinite shear rate; $[ η 0 ]$ is the limit of intrinsic viscosity at zero shear.

Source:

PAC, 1979, 51, 1213 (Manual of symbols and terminology for physicochemical quantities and units. Appendix II: Definitions, terminology and symbols in colloid and surface chemistry. Part 1.13. Selected definitions, terminology and symbols for rheological properties) on page 1217