Effects of the variation of mass loading and particle density in gas-solid particle flow in pipesKartušinski, Aleksander; Michaelides, Efstathios; Hussainov, Medhat; Rudi, ÜloPowder technology2009 / 2, p. 176-181 https://www.sciencedirect.com/science/article/pii/S0032591009001958