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.
For more advanced types, see Advanced Reactors and Small Reactors papers, and also Generation IV reactors. A nuclear reactor produces and controls the release of energy from splitting the atoms of certain elements. In a nuclear power reactor, the energy released is used as heat to make steam to generate electricity. (In a research reactor the main purpose is to utilise the actual neutrons produced in the core. In most naval reactors, steam drives a turbine directly for propulsion.) The principles for using nuclear power to produce electricity are the same for most types of reactor. The energy released from continuous fission of the atoms of the fuel is harnessed as heat in either a gas or water, and is used to produce steam.