1. a Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Applied Research and Technology, Engineering and Physical Hazards Branch, 4676 Columbia Parkway MS-R5, Cincinnati, OH 45226
2. b Department of Environmental Health Sciences, University of South Carolina, Columbia, S.C.
3. c Department of Mechanical Engineering, University of South Carolina, Columbia, S.C.
4. d Department of Mechanical and Nuclear Engineering, College of Engineering, Kansas State University, Manhattan, KS 66506