a
National Energy Technology Laboratory, Department of Energy, 3610 Collins Ferry Road, Morgantown, USA
b
Department of Mechanical and Aerospace Engineering, WVNano Initiative, West Virginia University, Morgantown, USA
E-mail: nick.wu@mail.wvu.edu
;
Fax: +1-(304)-293-6689
;
Tel: +1-(304)-293-3326
c
URS Corporation, Morgantown, USA
d
Institute of Energy and Climate Research, IEK-1 Forschungszentrum, Jülich GmbH, 52425 Jülich, Germany