1. Chemical Engineering Programme Universiti Teknologi PETRONAS, Bandar Sri Iskandar 31750 Tronoh, Perak, Malaysia;, Email: Suriati@petronas.com.my
2. Chemical Engineering Programme Universiti Teknologi PETRONAS, Bandar Sri Iskandar 31750 Tronoh, Perak, Malaysia
3. School of Mechanical Materials and Manufacturing Engineering, University of Nottingham, Nottingham NG7 2RD, UK