Correction: Tap density equations of granular powders based on the rate process theory and the free volume concept.

Correction for 'Tap density equations of granular powders based on the rate process theory and the free volume concept' by Tian Hao et al. The authors regret the following errors in eqns (23), (24) and (26). The corrected equations are shown below. The section on page 4 The energy owing from the shaker to the powder 36 is: EðtÞ ¼ M g L 0 u p (23) where M g is the weight of powder. The total energy owing to the powder aer a series of tapping processes with the tapping number, n, may be expressed as: E ¼ nEðtÞ ¼ nM g L 0 u p (24) should be corrected to The energy owing rate from the shaker to the powder 36 is: EðtÞ ¼ MgL 0 u 2p (23) where Mg is the weight of powder. The total energy owing to the powder aer a series of tapping processes with the tapping number, n, may be expressed as: E ¼ nE(t)t ¼ nMgL 0 (24) where t is the time spent for one tap.