generally, the evaluation and assessment critical condition of rill formation are useful for a better understanding of soil erosion processes. the inherence characteristics of soils, which have much dynamic variations on the hill-slopes and are affected by rill formation, are the soil critical shear stress and soil erodibility factors. this study aims to assess experimental rill incision thresh...

Platelet activation in blood flow under high, overcritical shear rates is initiated by Von Willebrand factor. Despite the large amount of experimental data that have been obtained, the value of the critical shear rate, above which von Willebrand factor starts to activate platelets, is still controversial. Here, we recommend a theoretical approach to elucidate how the critical blood shear rate i...

2014 The apparent viscosity of dilute polymer solutions in non-inertial flows through channels consisting of successive short tubes or slits separated by expansions displays a marked divergence from shear-thinning powerlaw behaviour beyond a critical shear rate calculated for constricted sections. The product of this critical shear rate by the Rouse relaxation time was found to be nearly consta...

We report here the nonlinear rheological properties of metallo-supramolecular networks formed by the reversible cross-linking of semi-dilute unentangled solutions of poly(4-vinylpyridine) (PVP) in dimethyl sulfoxide (DMSO). The reversible cross-linkers are bis-Pd(II) or bis-Pt(II) complexes that coordinate to the pyridine functional groups on the PVP. Under steady shear, shear thickening is obs...

The present study describes entrainment characteristics of bed material into debris flow, based on flume tests, numerical and dimensional analyses. Flume tests are conducted to investigate influences of bed sediment size on erosion rate by supplying debris flows having unsaturated sediment concentration over erodible beds. Experimental results show that the erosion rate decreases monotonically ...

– A new mechanism is suggested for shear thickening in dilute solutions of wormlike micelles. According to this mechanism, there is an instability above a critical shear rate, γ̇c, by which micelles aggregate to form networks of bundles. We examine the first step of this instability by studying the aggregation of two micelles into a paired bundle. The model predicts that γ̇c is given by the inver...

In startup of steady shearing flow of two viscous unentangled liquids, namely low-molecular-weight polystyrene and -Dglucose, the shear stress catastrophically collapses if the shear rate is raised above a value coresponding to a critical initial shear stress of around 0.1-0.3 Mpa. The time-dependence of the shear stress during

A hexagonal columnar crystal undergoes a shear-melting transition above a critical shear rate or stress. We combine the analysis of the shear-thinning regime below the melting with that of synchrotron x-ray scattering data under shear and propose the melting to be due to a proliferation of dislocations, whose density is determined by both techniques to vary as a power law of the shear rate with...