A. S. Rangwala received a Master of Science degree in Mechanical Engineering from Drexel University, Philadelphia, and a Master of Science degree in Industrial Engineering from the University of Cincinnati. He has worked for three decades in the field of structural dynamics on compressors and gas turbines applicable to aircraft engines, and steam turbines and generators for power plant applications. Mr. Rangwala has written papers and reports on all facets of machinery system and component dynamics. He has worked in General Electric Company's Aircraft Engines Group, both in Cincinnati and in Lynn, Massachusetts, and in GE's Large Steam Turbines Department in Schenectady, New York. Mr. Rangwala has also worked at Siemens-Westinghouse Power Corporation in Orlando, Florida. He now works as an international consultant and teaches short courses for practicing engineers on structural vibrations of rotating and reciprocating machinery. He has also served as an adjunct professor at Cincinnati State Technical College.