ELFT HÍRADÓ

["Varga Imre" <varga AT galilei.phy.bme.hu>]

                                                 MEGHIVO
                           a BME Fizikai Intezet, Elmeleti Fizika Tanszek
                                             szeminariumara:


                                               Anita Mehta
                           S.N. Bose Centre for Basic Sciences
                                       Kolkata (Calcutta), India

                                           "Sand in a Jam"


       Helye: BME Fizikai Intezet,
                 Elmeleti Fizika Tanszek
                 Budafoki ut 8.
                 F-epulet, III. lepcsohaz, mfszt. Szeminariumi szoba

       Ideje: 2008. majus 23. pentek, 10:15.

       Kivonat: Granular dynamics are by now well known to consist of both
fast and slow
       relaxational processes.  I will first outline several structural
features that we have
       established; these include, most recently, the formation of stable
bridges, which are
       signatures of spatiotemporal inhomogeneities. I will review their
geometrical
       characteristics obtained via theory and independent simulations, and
speculate on their
       relationship to force chains. In the second part of the talk, I will
look specifically at
       models of granular compaction, presenting a random graph model used
to model
       compaction near jamming. The compaction curve shows distinct reasons
where fast
       and slow dynamics apply, separated by the single-particle relaxation
threshold. Finally,
       I will present a model of a jammed column of grains, which exhibits
spatial
       heterogeneity in its dynamics. Major results include: an entropic
landscape that, while
       microscopically rough, manifests Edwards' flatness at a macroscopic
level; and the
       manifestation of intermittent dynamics in the fully jammed base of
the column as the
       system reaches one of many metastable attractors.


       Minden erdeklodot szivesen latunk.



           Varga Imre