Nanoemulsions are metastable dispersions of nanodroplets of one liquid that have been ruptured by shear in another immiscible liquid. The ruptured droplets are stabilized against subsequent coalescence by a surfactant. Because the nanodroplets do not form spontaneously, as they can in lyotropic “microemulsion” phases, the structure of nanoemulsions is primarily dependent on the history of the a...

In this article, a new higher order shear deformation theory based on trigonometric shear deformation theory is developed. In order to consider the size effects, the nonlocal elasticity theory is used. An analytical method is adopted to solve the governing equations for static analysis of simply supported nanoplates. In the present theory, the transverse shear stresses satisfy the traction free...

We present measurements of human blood hemolysis caused by laminar shear stresses ranging from 50 to 500 Pa for exposure times extending from 60 to 300 s using a Taylor-Couette device. A viscoelastic model is proposed that captures the response of the red blood cells to shear stress. The model is based on well-established mechanical properties of the red blood cell membrane, and shows good agre...

Sixteen large-scale reinforced concrete specimens without web reinforcements were tested to study the behavior of typical bridge piers subjected to deflection reversals that were large enough to cause extensive yielding of the longitudinal reinforcement. The different parameters considered included shear spanto-depth ratio, percentage of longitudinal reinforcement, frequency of the applied load...

Numerical predictions of blood flow patterns and hemodynamic stresses in Abdominal Aortic Aneurysms (AAAs) are performed in a two-aneurysm, axisymmetric, rigid wall model using the spectral element method. Homogeneous, Newtonian blood flow is simulated under steady conditions for the range of Reynolds numbers 10 < or =Re < or =2265. Flow hemodynamics are quantified by calculating the distributi...

The aim of the present research is to investigate the fatigue behaviour of friction stir (FS) welded tubular joints in aluminium alloy subjected to torsional fatigue loading. To manufacture the samples which were tested, an MTS I-STIR process development system was equipped with a retracting tool specifically designed for these tubular welds. Al 6082-T6 FS welded samples were tested under cycli...

Cells continuously sense and respond to external mechanical forces through their cytoskeleton. Here we show that only a small subset of actin fibers, those forming the perinuclear actin cap that wraps around the nucleus, form in response to low physiological mechanical stresses in adherent fibroblasts. While conventional basal stress fibers form only past a threshold shear stress of 0.5 dyn/cm(...

Using stress sensitive FRET sensors we have measured cytoskeletal stresses in α-actinin and the associated reorganization of the actin cytoskeleton in cells subjected to chronic shear stress. We show that long-term shear stress reduces the average actinin stress and this effect is reversible with removal of flow. The flow-induced changes in cytoskeletal stresses are found to be dynamic, involvi...

The stationary, shear rate dependent flow curves of yielding glasses are discussed within a mode coupling theory approach. Asymptotic formulae for the shear stress at the transition point are obtained that take the form of generalized Hershel–Bulkeley constitutive equations, and enable one to find dynamical yield stresses by extrapolation. (Some figures in this article are in colour only in the...

AIMS In early human pregnancy placental trophoblasts migrate along uterine spiral arteries (SAs) and remodel these vessels into wide-bore conduits in a process essential for successful pregnancy. Until 10-12 weeks gestation trophoblasts plug spiral arteries, resulting in slow, high-resistance blood flow. This work examined the consequences of these low shear stress conditions on trophoblast mig...