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 oxide gas is the active drug used by dentists in inhalation sedation dentistry to offer comfortable and pain-free treatments and help their patients to overcome their dental fear and anxiety. Even if you do not have a dental phobia, use of nitrous oxide sedation can help increase your level of comfort during dental procedures and shorten treatment time. It is considered as the safest alternative to other types of dental sedation such as intravenous conscious sedation and general anesthesia. Chemistry of Nitrous Oxide The chemical formula of nitrous oxide is N 2 O, also called Dinitrogen Monoxide. It is one of the several oxides of nitrogen; the others most known are nitric oxide (NO) and nitrogen dioxide NO 2. The nitrous oxide moleculeâs structure is a linear chain of two nitrogen atoms, with the second one bound to an oxygen atom.