1. Department of Mathematics and Statistics, Memorial University of Newfoundland, St. John's, NL A1C 5S7, Canada e-mail:
2. Professor Fellow ASME Department of Mechanical Engineering, Memorial University of Newfoundland, St. John's, NL A1B 3X5, Canada e-mail:
3. Professor Department of Mathematics and Statistics, Memorial University of Newfoundland, St. John's, NL A1C 5S7, Canada e-mail: