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We exploit the recent developments of microfluidic technologies to investigate the collective shear-induced diffusion in suspensions of micron-sized particles. Whereas spherical particles do not diffuse on the time scale of our experiments, the results with platelike clay particles show a strong cross-stream shear-induced diffusivity at low volume fraction (phi{0}<or=0.01). Moreover, we find a ...

Strongly confined active liquids are subject to unique hydrodynamic interactions due to momentum screening and lubricated friction by the confining walls. Using numerical simulations, we demonstrate that two-dimensional dilute suspensions of fore-aft asymmetric polar swimmers in a Hele-Shaw geometry can exhibit a rich variety of novel phase behaviors depending on particle shape, including coher...

A recently developed first-principles approach to the non-linear rheology of dense colloidal suspensions is evaluated and its results compared to those from simulations of sheared systems close to their glass transitions. The predicted scenario of a universal transition of the structural dynamics between yielding of glasses and non-Newtonian (shear-thinning) fluid flow appears well obeyed, and ...

A theory describing magneto-orientational properties of suspensions containing antiferromagnetic nanoparticles is developed. Due to their small size, these particles possess, apart from an anisotropic magnetic susceptibility pertinent to antiferromagnets, a spontaneous magnetic moment caused by sublattice decompensation. In a colloid subjected to a DC field of increasing strength an orientation...

We consider the problem of the simultaneous tests of matching and non-unifiability (logically: entailment and disentailment over trees) where the input consists of one fixed term (one fixed constraint) and an incrementally growing set of variable bindings (the constraint store). These tests are used in logic programming systems with suspensions, e.g. for proving guards as in LIFE, AKL and Oz. A...

The technique of preparing active cell suspensions of Cl. acetobutylicum (Weizmann) capable of giving normal fermentation products from glucose has been described [Davies & Stephenson, 1941]. It was stated that these suspensions rapidly lost their activity. In the present paper further experiments on the decay of activity are described and also various experiments on reactions performed by susp...

The gravity sedimentation of three narrow-sized fractions of suspensions of magnetite particles exposed to magnetic fields ranging from 0 to 180 x 10 -4 T was studied experimentally. At volumetric solids concentrations in excess of 15%, the magnetized suspensions of magnetite with size fractions ranging from -75 to +38 μm settled more slowly than the non-magnetized suspensions. However, owing t...

A photoelectric turbidimeter is described for use in measuring cell concentrations in thick suspensions. Its sample cuvette provides a path length continuously adjustable between 0.01 and 20.00 mm. By reducing the path length, it is possible to measure the optical density in thick cell suspensions without dilution. Moreover, the method described is rapid and simple, and only small amounts (less...