The pinch-off of an air bubble from an underwater nozzle ends in a singularity with a remarkable sensitivity to a variety of perturbations. I report on experiments that break both the axial (i.e., vertical) and azimuthal symmetry of the singularity formation. The density of the inner gas influences the axial asymmetry of the neck near pinch-off. For denser gases, flow through the neck late in c...

We implemented a tridirectional survey to begin the standardization process for grasp and pinch terminology and protocols for testing and to improve the communication between rehabilitation professionals who assess hand strength. We surveyed the literature, occupational therapy clinics across the country, and occupational therapy educational programs. Our results reveal the current use, teachin...

The formation of bubbles by flow focusing of a gas and a liquid in a rectangular channel is shown to depend strongly on the channel aspect ratio. Bubble breakup consists in a slow linear 2D collapse of the gas thread, ending in a fast 3D pinch-off. The 2D collapse is predicted to be stable against perturbations of the gas-liquid interface, whereas the 3D pinch-off is unstable, causing bubble po...

Particle transport in magnetized plasmas is investigated with a fluid model of drift wave turbulence. An analytical calculation shows that magnetic field curvature and thermodiffusion drive an anomalous pinch. The curvature driven pinch velocity is consistent with the prediction of turbulence equipartition theory. The thermodiffusion flux is found to be directed inward for a small ratio of elec...

We present data on the pinch-off and coalescence of thin liquid alkane lenses floating on water. Pinch-off in quasi-2D lenses is distinctly different from pinch-off in axisymmetric 3D drops and involves a cascade of satellite droplets which extends to micron length scales. In contrast, coalescence of lenses is qualitatively similar to coalescence of 3D drops. Coalescence is predicted to involve...

Pinch-outs refers to the gradual thinning of thickness sedimentary layer laterally until there is no deposition and are a major topic modern research on automated drawing geological profiles. The rapid development smart systems imposed an urgent need for high-speed, accurate methods plot pinch-outs. However, because their complexity, excessive number branch paths, low rendering speed, poor reli...

This paper focuses on presenting a technique to calculate energy retrofit horizons in process plants. In particular, it focuses on crude fractionation units. The methodology takes advantage of two facts: (a) Pinch-type calculations can be performed using operator type representations and (b) Processes like crude fractionation offer large flexibility in the operating/design parameters. This pape...

The presence of a very small amount of high molecular weight polymer significantly delays the pinch-off singularity of a drop of water falling from a faucet and leads to the formation of a long-lived cylindrical filament. In this Letter, we present experiments, numerical simulations, and theory which examines the pinch-off process in the presence of polymers. The numerical simulations are found...

Chronic venous ulcers are common, and even with effective compression or elevation large ulcers may take months to heal. Pinch skin grafting may allow healing from epithelial islands throughout the surface area of the ulcer, and a prospective randomised trial was therefore conducted comparing this treatment with porcine dermis dressings. Most patients were treated as outpatients, 25 ulcers bein...