The Galerkin weighted residuals method is extended solve the laminar, fully developed flow and heat transfer of Al2O3-water nanofluid inside polygonal ducts with round corners for the constant heat flux and uniform wall temperature boundary conditions. Using the method, semi-analytical, closed-form solutions are obtained for the friction coefficient and the Nusselt number in terms of the radius...

(Received) We give an equation satissed by the generating function for parallelogram polyominoes according to the area, the width and the number of left path corners. Next, we give an explicit formula for the generating function of these polyominoes according to the area, the width and the number of right and left paths corners.

Research in requirements engineering has produced an extensive body of knowledge, but there are four areas in which the foundation of the discipline seems weak or obscure. This paper shines some light in the "four dark corners," exposing problems and proposing solutions. We show that all descriptions involved in requirements engineering should be descriptions of the environment. We show that ce...