1. INFLUENCE OF THE Ni/Mg RATIO ON THE COLOUR OF SPINEL PIGMENTS PREPARED BY A MODIFIED SOL – GEL METHOD . Authors: THOMAS DIPPONG, CSABA VARHELYI JR., ALEXANDRU HORATIU MARINCAS, ALEXANDRA AVRAM, LILIANA BIZO, ROXANA DUDRIC, FIRUTA GOGA.2. REMINERALIZATION OF TOOTH ENAMEL WITH HYDROXYAPATITE NANOPARTICLES: AN IN VITRO STUDY. Authors: DIANA ALEXANDRA FLOREA, AURORA MOCANU, LUCIAN CRISTIAN POP, GHEORGHE TOMOAIA, CRISTINA-TEODORA DOBROTA, CSABA VARHELYI JR., MARIA TOMOAIA-COTISEL.