Rear Admiral David J. HahnChief of Naval Research. Director, Innovation Technology Requirements, and Test and Evaluation. Raised in Tampa, Florida, Rear Admiral David Hahn graduated from the U.S. Naval Academy with distinction in 1985, earning a Bachelor of Science degree in Mechanical Engineering.
Plastic optical fiber (POF) (or Polymer optical fibre) is an optical fiber that is made out of polymer.Similar to glass optical fiber, POF transmits light (for illumination or data) through the core of the fiber.Its chief advantage over the glass product, other aspect being equal, is its robustness under bending and stretching.ne of the most exciting developments in polymer fibers has been the development of microstructured polymer optical fibers (mPOF), a type of photonic crystal fiber. POF fiber also has applications in sensing. It is possible to write fiber Bragg gratings in single and multimode POF.
Q1. Medium Density Fibreboard (MDF) is an engineered wood-based sheet material made by bonding together wood fibres with a synthetic resin adhesive. MDF is extremely versatile and can be machined and finished to a high standard. First, try to reduce risks at source where possible by using a lower risk alternative, where one exists. 2  An example of this could be to use a âno added formaldehydeâ MDF board or low-emission MDF board if practicable to do so. 3  There should be an effective dust extraction system in use whenever MDF is machined or sanded.