“…Thus ∆ can be written as a function of , , , , , , , , particle shape and adhesion i.e. or (∆ , , , , , , , , , ℎ , ℎ )=0 (2) Following the Buckingham Π theorem [36] used in dimensional analysis, by taking , and as independent variables, three dimensionless groups can be formed as follows: -50mm PH101-75mm PH101-100mm PH102-50mm PH102-75mm PH102-100mm PH200-50mm PH200-75mm PH200-100mm PH302-50mm PH302-75mm PH302-100mm…”