1. Department of physics, The University of Maroua, Maroua, Cameroon
2. Wood Engineering Department, Higher Technical Teacher’s Training College, University of Ebolowa, Ebolowa, Cameroon
3. University of Lorraine, INRAE, LERMAB, ERBE – F, Epinal, France
4. CFA – CFPPA of Mirecourt, Mirecourt, France
5. Department of Agricultural and Bio-Resources Engineering, Michael Okpara University of Agriculture Umudike, Umuahia, Nigeria
6. School of Engineering and Engineering Technology, Federal University of Technology, Owerri, Nigeria
7. Laboratoire de Matière Condensée et Sciences Interdisciplinaires « Unité de Recherche Labellisée CNRST» URL-CNRST-17, Faculty of Sciences, Mohammed V University in Rabat, Rabat, Morocco
8. INRAE, LERMAB, ERBE, Faculty of Sciences and Techniques, University of Lorraine, Vandoeuvre-lès-Nancy, France