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 pictures to the right are of the same class of submarine (Ohio Class), and the second picture has two identical submarines, one on the pier and one in the water next to it. Types of Submarines - Fast Attacks (SSNs) There are 3 types of fast attack submarines in the U.S. Navy.