Eriawan Rismana
Agency for the Assessment and Application of Technology Jl. M. H. Thamrin No. 8 Jakarta 10340

Hadi Nur
Ibnu Sina Institute for Fundamental Science Studies-Universiti Teknologi Malaysia 81310 UTM Skudai, Johor Darul Takzim, Malaysia

Salasiah Endud
Department of Chemistry-Universiti Teknologi Malaysia 81310 UTM Skudai, Johor Darul Takzim, Malaysia