We describe a simple experimental tool that enables stability of multicomponent nanoparticle suspensions to be readily assessed by establishing a confinement-imposed chemical discontinuity at the interface between co-flowing laminar streams in a microchannel. When applied to examine Al(2)O(3) nanoparticle suspensions, this method readily reveals compositions that are susceptible to aggregation ...

We provide a reciprocal relation linking the e ective conductivity of a composite with highly conducting phase interfaces to that of a composite with the same phase geometry but with an electrical contact resistance at phase interfaces. A eld relationship linking the electric eld inside a composite with highly conducting phase interfaces to the current in a composite with contact resistance bet...

This article reports a comparative study of the nanoscale and macroscale tribological attributes of alumina and stainless steel surfaces immersed in aqueous suspensions of positively (hydroxylated) or negatively (carboxylated) charged nanodiamonds (ND). Immersion in -ND suspensions resulted in a decrease in the macroscopic friction coefficients to values in the range 0.05-0.1 for both stainless...

Abstract The multiscale stochastic simulation method based on the marriage of Brownian Configuration Field (BCF) and Radial Basis Function mesh-free approximation for dilute fibre suspensions by our group, is further developed to simulate non-dilute suspensions. For present approach, macro micro processes proceeded at each time step are linked other a contributed stress formula associated with ...

Measurement of the sizes and concentration of particles in colloidal suspensions has been a challenge particularly for suspensions with particles smaller than 100 nanometers. A new measurement technique has been developed that allows for measurement of particles as small as 5 nanometers in these suspensions. This new approach, uniquely combining proven techniques used for counting and sizing ae...

This paper presents a novel device based on an oscillating torsion resonator with continuously varying frequency capability to characterize the rheological properties of pulp fiber suspensions in a concentrated regime. Fiber suspensions made from unbleached wheat straw pulp at concentrations ranging from 5 wt% to 15 wt% were used. Pulp suspensions exhibit shear-thinning behavior up to a limited...

Yielding and flow transitions in bi-disperse suspensions of particles are studied using a model system comprised of self-suspended spherical nanoparticles. An important feature of the materials is that the nanoparticles are uniformly dispersed in the absence of a solvent. Addition of larger particles to a suspension of smaller ones is found to soften the suspensions, and in the limit of large s...

A key step in the processing of ceramics is the consolidation of powders into engineered shapes. Colloidal processing uses solvents (usually water) and dispersants to break up powder agglomerates in suspension and thereby reduce the pore size in a consolidated compact. However, agglomeration and particle rearrangement leading to pore enlargement can still occur during drying. Therefore, it is b...

Electrorheological (ER) fluid, which can be transformed rapidly from a fluid-like state to a solid-like state under an external electric field, is considered to be one of the most important smart fluids. However, conventional ER fluids based on microparticles are subjected to challenges in practical applications due to the lack of versatile performances. Recent researches of using nanoparticles...

The process by which senior hospital doctors are disciplined within the National Health Service is analysed. The mechanisms used are discussed and a number of faults are identified. Many of these faults give an unfair advantage to management and are contrary to the rules of 'Natural Justice'. These faults lead to an excessive number of doctors being wrongfully suspended for an unnecessarily lon...