"This study covers three Geldart groups, and includes state-of-the-art experimental measurements and first-principles prediction... The authors solved a longstanding problem in fluidization, namely extremely low Sherwood number of fine particles in fluidized beds... The authors showed that the well-known core-annulus profile reverses in slugging fluidization of Geldart D particles due to particle inertia effects... This new finding is a robust and important one since core-annulus behavior is not desired... These contributions to the field of particle technology are of high impact, and expected to be of lasting influence..." -Christine Hrenya, Professor of Chemical and Biological Engineering, University of Colorado at Boulder. "The authors have shown that we can eliminate the core-annular regime in risers... By directly computing the mass transfer coefficients, the need to include empirical parameters could be eliminated to obtain more accurate conversion rates..."-Reza Mostofi, Ph.D., UOP, A Honeywell Company.