The Main-Sequence: The star now settles down to a long period of stability while the hydrogen at its centre is converted into helium with the release of an enormous amount of energy. This stage is called the main-sequence stage, a reference to the classical Hertsprung-Russell diagram (see the Figure below). Most stars lie in a well defined band in the diagram, and the only parameter that determines where in the band they lie is the star's mass.
Becoming a Professional Engineer (PE) A Professional Engineer (PE) is an engineer certified by a state board of registration to practice engineering. The PE license is the engineering profession's highest standard of competence, a symbol of achievement and assurance of quality. The College of Engineering believes that professional registration is an important goal for engineering graduates. Passing the FE Exam is the first step toward that goal.
Human-factors engineering, also called ergonomics or human engineering, science dealing with the application of information on physical and psychological characteristics to the design of devices and systems for human use. 1  The term human-factors engineering is used to designate equally a body of knowledge, a process, and a profession. As a body of knowledge, human-factors engineering is a collection of data and principles about human characteristics, capabilities, and limitations in relation to machines, jobs, and environments.