1. EXISTENCE AND MULTIPLICITY OF POSITIVE RADIAL SOLUTIONS TO THE DIRICHLET PROBLEM FOR NONLINEAR ELLIPTIC EQUATIONS ON ANNULAR DOMAINS. Authors: NOUREDDINE BOUTERAA, SLIMANE BENAICHA.2. A STUDY OF EXISTENCE AND MULTIPLICITY OF POSITIVE SOLUTIONS FOR NONLINEAR FRACTIONAL DIFFERENTIAL EQUATIONS WITH NONLOCAL BOUNDARY CONDITIONS. Authors: SLIMANE BENAICHA, NOUREDDINE BOUTERAA.