In this paper, analytical and numerical methods for simulating squeeze-film air damping affecting suspended and perforated movable micro-surfaces are analyzed. Numerical solutions are obtained by full 3-D Navier-Stokes numerical analysis, carried out by a commercial finite element code, COMSOL Multiphysics, and are compared with those obtained using different analytical models proposed in liter...

acrophages can clean up the detritus of dying cells. But that, say Jody Rosenblatt, Martin Raff, and Louise Cramer (University College London, London, UK), is not the whole story. They have found that cells undergoing apoptosis in an epithelial sheet signal to their neighbors to begin squeezing, in a process that maintains the barrier function of the epithelium while extruding the dying cell. M...

We are aware that all information published by each issue of this journal needs the squeeze and sweat of thousands of people. On one end of the rope, researchers and higher education institutions work hard to produce science to the highest degree of excellence. On the other end, reviewers silently filter manuscripts, thus improving the quality and accuracy of information that has been approved....

The properties of butane (C4H10) lubricants confined between two approaching solids are investigated by a model that accounts for the curvature and elastic properties of the solid surfaces. We consider the linear n-butane and the branched isobutane. For the linear molecule, well defined molecular layers develop in the lubricant film when the width is of the order of a few atomic diameters. The ...

We characterize the linear viscoelastic shear properties of an aqueous wormlike micellar solution using diffusing wave spectroscopy (DWS) based tracer microrheology as well as various mechanical techniques such as rotational rheometry, oscillatory squeeze flow, and torsional resonance oscillation covering the frequency range from 10(-1) to 10(6) rad/s. Since DWS as well as mechanical oscillator...

We investigate the sensitivity of pionic bounce{oo and squeeze{out on the density and momentum dependence of the real part of the nucleon optical potential. For the in{plane pion bounce{oo we nd a strong sensitivity on both the density and momentum dependence whereas the out{of{plane pion squeeze{out shows a strong sensitivity only towards the momentum dependence but little sensitivity towards ...

Aim of this work was to test the idea of J.-Y.Ollitrault about the parallel squeeze-out type of transversal flow in mid-rapidity region [1]. For this purpose we have performed a computer simulation of the expanding pion gas created in non-central Pb-Pb 158GeV/n collisions. A squeeze-out type of asymmetry parallel to impact parameter in az-imuthal distribution of pions is found and studied. The ...

⎯ A technique for dynamic positioning of the movable electrode in an electrostatic actuator enables stable operation beyond the pull-in displacement and is used to perform squeeze-film damping measurements for different film thicknesses. Measurements at Knudsen numbers ranging between 0.03 and 0.18 are performed. Compact parallel-plate squeeze-film models are verified using the experimental res...

Guest exchange in an M4L6 supramolecular host has been evaluated to determine whether host rupture is required for guest ingress and egress. Two mechanistic models were evaluated: one requiring partial dissociation of the host structure to create a portal for guest passage and one necessitating deformation of the host structure to create a dilated aperture for guest passage without host rupture...

We present initial results from our new two-dimensional (radius and latitude), self-consistent model of galactic cosmic rays in the heliosphere. We focus on the latitudinal variations in the solar wind flow caused by the energetic particles. Among other things our results show that the cosmic rays significantly modify the latitudinal structure of the solar wind flow downstream of the terminatio...