1Department of Mathematics, National Technical University of Athens, Heroon Polytechneiou 9, 15780 Athens, Greece 2Department of Mathematics, 303 Lockett Hall, Louisiana State University, Baton Rouge, LA 70803-4918, USA 3Department of Mechanical and Industrial Engineering, 2508 Patrick F. Taylor Hall, Louisiana State University, Baton Rouge, LA 70803-6413, USA 4Department of Mechanical and Aero...
