... satisfying 1.1. For this end, we transform1.1 into an integral equation involving the appropriate Green function and seek fixed pointsof the following integral operator.Define an operator T ... Nonlinear Problems in Abstract Cones, vol. 5 of Notes and Reports in Mathematics in Science and Engineering, Academic Press, Boston, Mass, USA, 1988.Boundary Value Problems 9We seek positive solutions ... uσ211.6 and obtained the existence of positive solutions by using a fixed point theorem due to Gaticaet al. 14, where f : 0, 1 × 0, ∞ → 0, ∞ is decreasing in u for every t ∈ 0, 1 and mayhave...