1. SINGULARITY OF A BOUNDARY VALUE PROBLEM OF THE ELASTICITY EQUATIONS IN A POLYHEDRON. Authors: BENABDERRAHMANE BENYATTOU.2. VARIATIONAL ANALYSIS OF A CONTACT PROBLEM WITH FRICTION BETWEEN TWO DEFORMABLE BODIES. Authors: BENABDERRAHMANE BENYATTOU.3. GLOBAL NONEXISTENCE AND BLOW-UP RESULTS FOR A QUASI-LINEAR EVOLUTION EQUATION WITH VARIABLE-EXPONENT NONLINEARITIES. Authors: ABITA RAHMOUNE, BENABDERRAHMANE BENYATTOU.