1. EXPONENTIAL DECAY OF THE VISCOELASTIC WAVE EQUATION OF KIRCHHOFF TYPE WITH A NONLOCAL DISSIPATION. Authors: MOHAMED MELLAH, ALI HAKEM.2. BLOW-UP RESULTS FOR DAMPED WAVE EQUATION WITH FRACTIONAL LAPLACIAN AND NON LINEAR MEMORY. Authors: TAYEB HADJ KADDOUR, ALI HAKEM.