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.
When stored in a nitrous bottle, it is in a liquid state under pressure. When this liquid is released into the atmosphere, it instantly becomes a very cold gas. When it is injected into and engine, you are in effect supplying the motor with lots of cold air.