Sat, 26 Jul 2008 06:04:29 BST CiteULike: dchen's library [897 articles] http://www.citeulike.org/user/dchen/article/2606116 CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/dchen/article/2606116 <i>Physical Review Letters, Vol. 93, No. 1. (2004)</i><br /><br />Measurements of average velocity profiles in a bubble raft subjected to slow, steady shear demonstrate the coexistence between a flowing state and a jammed state similar to that observed for three-dimensional foams and emulsions [P. Coussot et al., Phys. Rev. Lett. 88, 218301 (2002)]. For sufficiently slow shear, the flow is generated by nonlinear topological rearrangements. We report on the connection between this short-time motion of the bubbles and the long-time averages. We find that velocity profiles for individual rearrangement events fluctuate, but a smooth, average velocity is reached after averaging over only a relatively few events. Velocity Profiles in Slowly Sheared Bubble Rafts John Lauridsen Gregory Chanan Michael Dennin doi:10.1103/PhysRevLett.93.018303 Physical Review Letters, Vol. 93, No. 1. (2004) 2008-03-28T12:36:40-00:00 2004 Physical Review Letters 93 1 APS bubbles shear shearband