For 10 points, give the general term for these objects that include blood and ketchup, which do not have a constant value for viscosity.
If the curve-fitting parameter ? in the Carreau equation is nonzero, then that equation describes these entities, and they are also described when the curve-fitting parameter n in the Ostwald-de Waele model is unequal to one.  One class of them is named after Boger, and some of their properties can be measured by the Bostwick test.  The Herschel-Bulkley model of these entities is a generalization of the Bingham model, which describes these entities as "plastics."  Another type of these entities is named after Casson and displays shear thinning above the ? yield criterion, and another group can be divided into rheopectic and thixotropic varieties.  For 10 points, give the general term for these objects that include blood and ketchup, which do not have a constant value for viscosity.
If the curve-fitting parameter ? in the Carreau equation is nonzero, then that equation describes these entities, and they are also described when the curve-fitting parameter n in the Ostwald-de Waele model is unequal to one.  
{non}-{Newtonian fluids} [do not accept or prompt on "fluid," as the first sentence uniquely applies to non-Newtonian fluids and not other kinds; besides, who would think this tournament would have a tossup on "fluids"?]