Reversing the Brazil-Nut Effect: Competition between Percolation and Condensation

摘要: We report on experiments vertically shaken binary granular mixtures, which separate into their components due to the external excitation. This well-known phenomenon, where large particles rise top of mixture, is called Brazil-nut effect. Recent theoretical findings predict also a reverse effect, sink bottom container. choose spherical beads various diameters and materials in order observe transition from effect its form. The direction demixing depends sensitively excitation, so that it possible switch between both effects for given mass density ratio.