1. Department of Mathematics, Carnegie Mellon University, Pittsburgh, PA 15213, USA
2. Department of Mathematics, University of Tennessee, Knoxville, TN 37996, USA
3. Supercomputer Computations Research Institute, Florida State University, Tallahassee, FL 32306, USA
4. Department of Chemical Engineering, FAMU/FSU College of Engineering, Tallahassee, FL 32310, USA