1. Measurement of solids circulation rates in circulating fluidized beds;Burkell,1988
2. The hour-glass theory of hopper flow;Davidson;Trans. Instn Chem. Engrs,1973
3. On the transient behaviour of the flow of particulate solids through a vertical slot;Davies,1992
4. Online measurement of the mean particle size of flowing bulk solids using a vertical slot;Davies,1995