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.
Nitrous and Auto Racing. In racing, nitrous is injected into an automobile's air intake to increase power. This isn't magic -- basically it is just providing more oxygen which allows more fuel to burn per stroke. The extra fuel per stroke gives you the extra power -- the nitrous just provides the oxygen needed to burn that fuel.