Coexistence of liquid and solid phases in flowing soft-glassy materials

Magnetic-resonance-imaging rheometrical experiments show that concentrated suspensions or emulsions cannot flow steadily at a uniform rate smaller than a critical value ((gamma)over dot(c) ). As a result, a liquid region (sheared rapidly, i.e., at a rate larger than (gamma)over dot(c) ) and a solid region (static) coexist. The behavior of the fluid in the liquid region follows a simple power-law model, while the extent of the solid region increases with the degree of jamming of the material.