Common Sleep Paralysis Causes: The Common Sleep Paralysis for most people, happens, during R.E.M. state, when the body releases hormones that paralyze the body to keep it from acting out dreams, thereby reducing any chances of physical harm during sleep.
Hybrid material. Hybrid materials are composites consisting of two constituents at the nanometer or molecular level. Commonly one of these compounds is inorganic and the other one organic in nature. Thus, they differ from traditional composites where the constituents are at the macroscopic (micrometer to millimeter) level.
Polyurethane is a very unique material -- a polymer composed of a chain of organic units. It is manufactured by a chemical reaction and depending on the different kinds of monomers used for the chain reaction, polyurethane can be either liquid foam or a solid.