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TZID:Europe/Paris
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BEGIN:VEVENT
UID:1-192@lptms.universite-paris-saclay.fr
DTSTART:20131021T113000Z
DTEND:20131021T120000Z
DTSTAMP:20131015T104441Z
URL:http://www.lptms.universite-paris-saclay.fr/seminars/journal-club-pier
 re-ronceray/
SUMMARY:Journal-Club : Pierre Ronceray - LPTMS\, salle 201\, 2ème étage\,
  Bât 100\, Campus d'Orsay - 21 Oct 13 11:30
DESCRIPTION:Improving the Density of Jammed Disordered Packings Using Ellip
 soids\nA. Donev\, I. Cisse\, D. Sachs\, E. A. Variano\, F. H. Stillinger\,
  R. Connelly\, S. Torquato\, and P. M. Chaikin\, Science\, 303\, pp 990-99
 3 (2004).\nPacking problems\, such as how densely objects can fill a volum
 e\, are among the most ancient and persistent problems in mathematics and 
 science. For equal spheres\, it has only recently been proved that the fac
 e-centered cubic lattice has the highest possible packing fraction f=Pi/sq
 rt(18) ~ 0.74. It is also well known that certain random (amorphous) jamme
 d packings have  f~0.64. Here\, we show experimentally and with a new sim
 ulation algorithm that ellipsoids can randomly pack more densely— up to 
 f~0.68 to 0.71 for spheroids with an aspect ratio close to that of M&amp\;
 M’s Candies—and even approach f~ 0.74 for ellipsoids with other aspect
  ratios. We suggest that the higher density is directly related to the hig
 her number of degrees of freedom per particle and thus the larger number o
 f particle contacts required to mechanically stabilize the packing. We mea
 sured the number of contacts per particle Z~10 for our spheroids\, as comp
 ared to Z~ 6 for spheres. Our results have implications for a broad range 
 of scientific disciplines\, including the properties of granular media and
  ceramics\, glass formation\, and discrete geometry.
LOCATION:LPTMS\, salle 201\, 2ème étage\, Bât 100\, Campus d'Orsay\, 15 
 Rue Georges Clemenceau\, Orsay\, 91405\, France
GEO:48.698185;2.181768
X-APPLE-STRUCTURED-LOCATION;VALUE=URI;X-ADDRESS=15 Rue Georges Clemenceau\,
  Orsay\, 91405\, France;X-APPLE-RADIUS=100;X-TITLE=LPTMS\, salle 201\, 2è
 me étage\, Bât 100\, Campus d'Orsay:geo:48.698185,2.181768
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