Wed, 20 Aug 2008 22:07:03 BST CiteULike: dchen Amarouchene http://www.citeulike.org/user/dchen/author/Amarouchene CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/dchen/article/2867652 <i>Physical Review Letters, Vol. 100, No. 21. (2008)</i><br /><br />We study the interface fluctuations of a granular jet falling under gravity and show that for small scales they are the analog of the thermally induced capillary waves. Experimental results from radial height and velocity fluctuations, static correlation functions and capillary ripple velocities allow us to estimate a granular surface tension. The ultralow interfacial tensions measured (of the order of 100 µN/m) can be rationalized using a simple model. Capillarylike Fluctuations at the Interface of Falling Granular Jets Yacine Amarouchene Jean Boudet Hamid Kellay doi:10.1103/PhysRevLett.100.218001 Physical Review Letters, Vol. 100, No. 21. (2008) 2008-06-05T20:44:07-00:00 2008 Physical Review Letters 100 21 APS cool flow fluctuation grains interface http://www.citeulike.org/user/dchen/article/2762925 <i>Physical Review Letters, Vol. 100, No. 14. (2008)</i><br /><br />A novel thermal convection cell consisting of half a soap bubble heated at the equator is introduced to study thermal convection and the movement of isolated vortices. The soap bubble, subject to stratification, develops thermal convection at its equator. A particular feature of this cell is the emergence of isolated vortices. These vortices resemble hurricanes or cyclones and similarities between our observed structures and these natural objects are found. This is brought forth through a study of the mean square displacement of these objects showing signs of superdiffusion. Thermal Convection and Emergence of Isolated Vortices in Soap Bubbles F Seychelles Y Amarouchene M Bessafi H Kellay doi:10.1103/PhysRevLett.100.144501 Physical Review Letters, Vol. 100, No. 14. (2008) 2008-05-06T21:07:23-00:00 2008 Physical Review Letters 100 14 APS 2008 bubble cool