Institution: | (1) Department of Physics and Atmospheric Sciences, Drexel University, 32nd & Chestnut Streets, 19104 Philadelphia, PA, U.S.A.;(2) Present address: Physics Department, University of Oregon, 97403 Eugene, OR, U.S.A.;(3) Istituto di Ricerca Sulle Onde Electromagnetiche (CNR-IROE), Via Panciatichi, 64-50127 Firenze, Italy |