1. b Dept. of Electrical Engineering , University of Texas at Dallas , Richardson , TX , 75080
2. a Department of Chemistry and Center for Analysis of Structures and Interfaces (CASI) , The City College of New York (CCNY) , New York , NY , 10031
3. c Proctor&Gamble Company , Winton Hill Technical Center. , 6100 Center Hill Ave., Cincinnati , OH , 45334
4. d Dept. of Electrical Engineering , Yeditepe University , Istanbul , 81410 , Turkey