Thu, 24 Jul 2008 23:12:28 BST CiteULike: dchens Abkarian http://www.citeulike.org/user/dchen/author/Abkarian CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/dchen/article/2553145 <i>Physical Review Letters, Vol. 98, No. 18. (2007)</i><br /><br />We reveal that under moderate shear stress (0.1 Pa) red blood cells present an oscillation of their inclination (swinging) superimposed to the long-observed steady tank treading (TT) motion. A model based on a fluid ellipsoid surrounded by a viscoelastic membrane initially unstrained (shape memory) predicts all observed features of the motion: an increase of both swinging amplitude and period (1/2 the TT period) upon decreasing , a -triggered transition toward a narrow range intermittent regime of successive swinging and tumbling, and a pure tumbling at low values. Swinging of Red Blood Cells under Shear Flow Manouk Abkarian Magalie Faivre Annie Viallat doi:10.1103/PhysRevLett.98.188302 Physical Review Letters, Vol. 98, No. 18. (2007) 2008-03-18T23:02:50-00:00 2007 Physical Review Letters 98 18 APS 2007 flow shear system http://www.citeulike.org/user/dchen/article/2552521 <i>Physical Review Letters, Vol. 99, No. 18. (2007)</i><br /><br />Experiments show that bubbles covered with monodisperse polystyrene particles, with particle to bubble radius ratios of about 0.1, evolve to form faceted polyhedral shapes that are stable to dissolution in air-saturated water. We perform Surface Evolver simulations and find that the faceted particle-covered bubble represents a local minimum of energy. At the faceted state, the Laplace overpressure vanishes, which together with the positive slope of the bubble pressure-volume curve, ensures phase stability. The repulsive interactions between the particles cause a reduction of the curvature of the gas-liquid interface, which is the mechanism that arrests dissolution and stabilizes the bubbles. Dissolution Arrest and Stability of Particle-Covered Bubbles Manouk Abkarian Anand Subramaniam Shin Kim Ryan Larsen Seung Yang Howard Stone doi:10.1103/PhysRevLett.99.188301 Physical Review Letters, Vol. 99, No. 18. (2007) 2008-03-18T19:09:16-00:00 2007 Physical Review Letters 99 18 APS 2007 colloids