when was kevlar first used as body armor
Bulletproof vest In 1971, research chemist Stephanie Kwolek discovered a liquid crystalline polymer solution. Its exceptional strength and stiffness led to the invention of KevlarÂ®, a synthetic fibre, woven into a fabric and layered, that, by weight, has five times the tensile strength of steel.[23] In the mid-1970s, DuPont the company which employed Kwolek introduced Kevlar. Immediately Kevlar was incorporated into a National Institute of Justice (NIJ) evaluation program to provide lightweight, able body armor to a test pool of American law enforcement officers to ascertain if everyday able wearing was possible. Lester Shubin, a program manager at the NIJ, managed this law enforcement feasibility study within a few selected large police agencies, and quickly determined that Kevlar body armor could be comfortably worn by police daily, and would save lives.
Bull riding The flank strap
Agent Orange Agent Orange was used in Korea in the late 1960s.[128]
Catalytic converter As an alternative, catalytic converters were moved to a third of the way back from the engine, and were then placed underneath the vehicle.
Kansas City preventive patrol experiment This was upheld for 12 months, from 1 October 1972 to 30 September 1973.
Vein Veins are less muscular than arteries and are often closer to the skin. There are valves in most veins to prevent backflow.