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DY: Dynamik und Statistische Physik
DY 24: Granular Matter
DY 24.3: Talk
Saturday, March 5, 2005, 14:45–15:00, TU H2032
Can one hear the state of a granulate? — •C.A. Krülle and A. Garcia-Sanchez — Experimentalphysik V, Universität Bayreuth, D-95440 Bayreuth
If an ensemble of macroscopic particles is mechanically agitated, for example by vertical vibrations, the energy input is dissipated into the system by multiple inelastic collisions. As a result, the granular material can exhibit several physical states, like a gaseous phase for high energy input or a condensated state for low agitation. The transition between these two phases can be identified clearly by the different noise level and its dominant frequency range. We introduce a new method for quantifying this acoustical response of the granular system which allows us to identify critical parameters of the phase transition.