Edema has many possible causes: 1  Prolonged standing or sitting, especially in hot weather, can cause excess fluid to accumulate in the feet, ankles and lower legs. 2  Tiny valves inside the veins of the legs can become weakened, causing a common problem called venous insufficiency.
Cars with nitrous-equipped engines can be identified by the purge of the delivery system that most drivers perform prior to reaching the starting line. A separate electrically operated valve is used to release air and gaseous nitrous oxide trapped in the delivery system.
1) An acronym for the brand name 'Nitrous Oxide Systems'. NOS produces a chemical known as nitrous oxide, often used in the performance optimization of car and motorcycle engines. The chemical (N2O) breaks up upon contact with air, releasing extra oxygen into the engine.