1 Clinical Psychologist: Doctorate Degree in Psychology (4 to 7 years of graduate school) 2  Industrial-Organizational Psychologist: Master's Degree (2 to 3 years of graduate school)  Forensic Psychologist: Master's Degree (2 to 3 years of graduate school); a doctoral degree is recommended.
Submarine Propulsion Systems. During World War II, most American submarines were powered by diesel-electric systems. This was a departure from earlier submarine power systems, which were direct drive types, little changed from the earliest boats. In this direct-drive power system, the diesel engine is directly connected to the propeller shaft.
The USA Navy as of 2008 operated 99. vessels powered by nuclear reactors including 10 nuclear powered aircraft carriers and 71. submarines. It has operated nuclear powered ships for more than 50 years. As of 2001, about. 235 naval reactors had been built at a unit cost of about $100 million for a submarine and $200.