The nanosized magnetite particles were synthesized by means of a coprecipitation method and used to prepare the aqueous ferrofluids with various volume fractions. The magnetorheological properties of the aqueous ferrofluids have been investigated as a function of magnetic field. Under steady-state shear, the apparent viscosity for all of the ferrofluids exhibited a shear thinning behavior. But ...

We investigate the critical role played by the mean micellar length during the route to rheochaos for wormlike micellar gels of surfactant cetyltrimethylammonium tosylate in the presence of salt sodium chloride that show coupling of flow to concentration fluctuations. To this end, we have carried out stress/shear rate relaxation experiments at a fixed shear rate/stress but at different temperat...

geometrically nonlinear governing equations for a plate with linear viscoelastic material are derived. the material model is of boltzmann superposi¬tion principle type. a third-order displacement field is used to model the shear deformation effects. for the solution of the nonlinear governing equations the dynamic relaxation (dr) iterative method together with the finite difference discretizati...

The viscosity of blood at high rates of shear is unusually low compared to other suspensions of similar concentration. The underlying mechanisms were studied by rotational viscometry, red cell filtration, viscometry of packed cells and direct microscopic observation of red cells under flow in a transparent cone plate viscometer. Deformability of red cells was altered osmotically or abolished by...

The transition from frictional to lubricated flows of a dense suspension of non-Brownian particles is studied. The pertinent parameter characterizing this transition is the Leighton number Le=eta(s)gamma / sigma, the ratio of lubrication to frictional forces. Le defines a critical shear rate below which no steady flow without localization exists. In the frictional regime the shear flow is local...

Shear band spacing in Zr-based bulk metallic glasses (BMGs) under dynamic loads is found to vary with position and local strain rate in the indented region. To investigate the dependence of shear band evolution characteristics on local strain rate and normal stress, a micromechanical model based on momentum diffusion is proposed. The thermomechanical model takes into account the normal stress d...

Shear-induced structural changes in complex fluids of anisotropic species are very general phenomena, occurring in polymer solutions, liquid crystalline materials and block copolymer melts. The purpose of our work is to investigate the influence of shear on the structure of a highly viscoelastic, aqueous clay-polymer solution. Many structural models have been proposed for such solutions [1-3], ...

We demonstrate that application of an increasing shear field on a glass leads to an intriguing dynamic first-order transition in analogy with equilibrium transitions. By following the particle dynamics as a function of the driving field in a colloidal glass, we identify a critical shear rate upon which the diffusion time scale of the glass exhibits a sudden discontinuity. Using a new dynamic or...

2014 Recently we have developed a Couette viscosimeter for studying the shearing of colloidal crystals. We report here that with increasing shear rate the colloidal crystal melts (for 03C9crit) and above a critical shear rate, 03C9T0, Taylor instabilities develop. After stopping the shearing flow the suspension recrystallizes in a special texture which preserves the pattern of the Taylor rolls....