“Studying the Factors Effect on the Flowability of (ZnO – CuO/ Al2O3) Catalyst with Blending of Different Lubricants through Hopper”, alkej, vol. 5, no. 4, pp. 18–24, Dec. 2009, Accessed: Nov. 22, 2024. [Online]. Available: https://alkej.uobaghdad.edu.iq/index.php/alkej/article/view/579