Self-Structuring of Granular Media under Internal Avalanches
  We study the phenomenon of internal avalanching within the context of recently proposed ``Tetris'' lattice models for granular media. We define a recycling dynamics under which the system reaches a steady state which is self-structured, i.e. it shows a complex interplay between textured internal structures and critical avalanche behavior. Furthermore we develop a general mean-field theory for this class of systems and discuss possible scenarios for the breakdown of universality. 
S. Krishnamurthy, V. Loreto, H.J. Herrmann, S.S. Manna and S. Roux