1. Department of Mechanical Engineering, Diponegoro University, Semarang, Indonesia
2. Department of Mechanical Engineering, Universitas Negeri Surabaya, Surabaya, Indonesia
3. Department of Chemical Engineering, UNTAG University in Semarang, Semarang, Indonesia
4. Department of Environmental Engineering, Diponegoro University, Semarang, Indonesia
5. Vacational Chemical Engineering Program, Catholic Polytechnic Mangunwijaya, Semarang, Indonesia
6. Department of Earth and Environmental Sciences, Ludwig-Maximilians- University of Munich, Munich, Germany