1. GROWTH RATE OF HYDROXYAPATITE CRYSTALS OBTAINED BY PRECIPITATION. Authors: PAUL ŞERBAN AGACHI, BOGYA ERZSÉBET SÁRA, ANA-MARIA CORMOŞ, REKA BARABAS, VALENTINA ROXANA DEJEU.2. KINETIC STUDIES OF SORPTION OF COPPER(II) IONS ONTO DIFFERENT CALCIUM-HYDROXYAPATIE MATERIALS. Authors: VALENTINA ROXANA DEJEU, GRAZIELLA L. TURDEAN, ALEXANDRA CSAVDÁRI, BARABÁS RÉKA, IOAN BÂLDEA, BOGYA ERZSÉBET SÁRA.3. APPLICATION OF NUMERICAL METHODS IN THE TECHNOLOGY OF HYDROXYAPATITE. Authors: PAUL ŞERBAN AGACHI, REKA BARABAS, SILVIA TOADER, VALENTINA ROXANA DEJEU.