Effect of the ratios of diameter of silo to bead on the pressure screening in granular columns A. Qadir, H. Guo, X. Liang, Q. Shi and G. Sun Eur. Phys. J. E, 31 3 (2010) 311-314 Published online: 23 March 2010 DOI: 10.1140/epje/i2010-10581-7