Development of Wind Tunnel for Ultrafine Palm Oil Fuel Ash Separator Sylvester Kenneth Sedah, Ana Sakura Zainal Abidin, A. Rigit, Mohd Azlan Ismail, Raudhah Ahmadi and Md Abdul Mannan MATEC Web Conf., 87 (2017) 02009 Published online: 12 December 2016 DOI: 10.1051/matecconf/20178702009