1. a Department of Physics , University of Guelph , Guelph , Ontario , N1G 2W1
2. b Department of Mechanical Engineering , S.U.N.Y. at Stony Brook, Stony Brook , Long Island , New York , 11794 , U.S.A.
3. c Department of Mathematics and Statistics , University of Guelph , Guelph , Ontario , N1G 2W1 , Canada
4. d School of Chemical Engineering, Cornell University , Ithaca , New York , 14853 , U.S.A.