A compact-sized falling needle rheometer with quick operation and automatic flow analysis has been developed for viscometry of human blood. The volume of a sample of blood only needs to be 4 mL and the measuring time is within 3 min. Measured flow properties of blood are evaluated as a flow curve showing the relationship between the shear stress and shear rate. Observed flow curves of the human...

The non-Newtonian flow properties of the wormlike surfactant system, cetyl pyridinium chloride/sodium salicylate in water, have been studied using dynamic and steady rheometry and nuclear magnetic resonance velocity imaging. The NMR measurements of velocity profiles across a 5.0 mm diameter glass tube reveal a discontinuity in the flow behaviour, once a critical shear strain rate of around I s~...

Fertilization is a complex interaction among biological traits of gametes and physical properties of the fluid environment. At the scale of fertilization (0.01-1 mm), sperm encounter eggs while being transported within a laminar (or viscous) shear flow. Varying laminar-shear in a Taylor-Couette flow tank, our experiments simulated important aspects of small-scale turbulence within the natural h...

Large-scale molecular-dynamics simulations are performed to study the steady-state yielding dynamics of a well-established simple glass. In contrast to the supercooled state, where the shear stress, , tends to zero at vanishing shear rate, ̇, a stress plateau forms in the glass which extends over about two decades in shear rate. This strongly suggests the existence of a finite dynamic yield str...

Flaw tolerance refers to a state in which a pre-existing crack-like flaw does not propagate even as the material is stretched to failure near its theoretical strength. Such an optimal scenario can be achieved when the characteristic length scale is reduced to below a critical value. So far, the critical conditions to achieve flaw tolerance have been discussed mostly for homogeneous materials or...

-We describe slip-rate dependent friction laws based on the Coulomb failure criteria. Frictional rate dependence is attributed to a rate dependence of cohesion c and friction angle qS. We show that differences in the stress states developed during sliding result in different Coulomb friction taws for distributed shear within a thick gouge layer versus localized shear within a narrow shear band ...