We use single-particle tracking to study the elastic properties of single microtubules grafted to a substrate. Thermal fluctuations of the free microtubule’s end are recorded, in order to measure position distribution functions from which we calculate the persistence length of microtubules with contour lengths between 2.6 and 48 μm. We find the persistence length to vary by more than a factor o...

Gravitational instability of a vertically thin, dusty sheet near the midplane of a protoplanetary disk has long been proposed as a way of forming planetesimals. Before Roche densities can be achieved, however, the dust-rich layer, sandwiched from above and below by more slowly rotating dust-poor gas, threatens to overturn and mix by the Kelvin-Helmholtz instability (KHI). Whether such a threat ...

A general analysis and experimental validation of transmission wavefront shearing interferometry for photoelastic materials are presented. These interferometers applied to optically isotropic materials produce a single interference pattern related to one phase term, but when applied to photoelastic materials, they produce the sum of two different interference patterns with phase terms that are ...

We report a simple method that uses (i) emulsion shearing with oxidation to make core-shell particles, and (ii) emulsion shearing with surface-tension driven phase segregation to synthesize particles with complex surface compositions and morphologies. Subjecting eutectic gallium-indium, a liquid metal, to shear in an acidic carrier fluid we synthesized smooth liquid core-shell particles 6.4 nm ...

We give an analysis of the stability and uniqueness of the simply laminated microstructure for all three tetragonal to monoclinic martensitic transformations. The energy density for tetragonal to monoclinic transformations has four rotationally invariant wells since the transformation has four variants. One of these tetragonal to monoclinic martensitic transformations corresponds to the shearin...

Introduction The material properties of the red cell membrane, in particular its unique stability towards shearing forces and its elasticity with respect to linear deformation, result from the interaction of the phospholipid bilayer with the membrane cytoskeleton that covers its cytoplasmic surface. When this protein network is extracted or destroyed by proteolysis the membrane spontaneously ve...

Many long skeletal muscles are comprised of fibers that terminate intrafascicularly. Force from terminating fibers can be transmitted through shear within the endomysium that surrounds fibers or through tension within the endomysium that extends from fibers to the tendon; however, it is unclear which pathway dominates in force transmission from terminating fibers. The purpose of this work was t...

I review a first principles approach to the non-linear rheology of dense colloidal dispersions. Assuming homogeneous flow and neglecting hydrodynamic interactions, a theoretical description of the stresses, micro-structure, and particle motion close to a colloidal glass transition are developed. Results for large amplitude oscillatory shearing, step-strains, and other time-dependent transient d...