Search results
Results from the WOW.Com Content Network
The term NO x represents several forms of nitrogen oxides such as NO (nitric oxide), NO 2 (nitrogen dioxide) and N 2 O (nitrous oxide, also known as laughing gas).In a gasoline engine, NO is the most common form of NO x at around 93%, while NO 2 is around 5% and the rest is N 2 O.
In atmospheric chemistry, NO x is shorthand for nitric oxide (NO) and nitrogen dioxide (NO 2), the nitrogen oxides that are most relevant for air pollution. [ 1 ] [ 2 ] These gases contribute to the formation of smog and acid rain , as well as affecting tropospheric ozone .
Nitric oxide (nitrogen oxide or nitrogen monoxide [1]) is a colorless gas with the formula NO. It is one of the principal oxides of nitrogen . Nitric oxide is a free radical : it has an unpaired electron , which is sometimes denoted by a dot in its chemical formula ( • N=O or • NO).
The NO x adsorber was designed to avoid the problems that EGR and SCR experienced. An adsorbent such as zeolite traps the NO and NO 2 molecules — acting as a molecular sponge. Once the trap is full (like a sponge full of water) no more NO x can be absorbed. Various schemes have been designed to "purge" or "regenerate" the trap.
Selective catalytic reduction (SCR) means converting nitrogen oxides, also referred to as NO x with the aid of a catalyst into diatomic nitrogen (N 2), and water (H 2 O). A reductant, typically anhydrous ammonia (NH 3), aqueous ammonia (NH 4 OH), or a urea (CO(NH 2) 2) solution, is added to a stream of flue or exhaust gas and is reacted onto a ...
NO y (or NOy) refers to the sum of NO x and all oxidized atmospheric odd-nitrogen species (e.g. the sum of NO x, HNO 3, HNO 2, etc.) NO z (or NOz) = NO y − NO x; Mixed Oxides of Nitrogen ("MON"): solutions of nitric oxide in dinitrogen tetroxide/nitrogen dioxide.
The sorption pump is a cyclic pump and its cycle has 3 phases: sorption, desorption and regeneration. In the sorption phase the pump is actually used to create a vacuum. This is achieved by cooling the pump body to low temperatures, typically by immersing it in a Dewar flask filled with liquid nitrogen.
A thermosiphon (or thermosyphon) is a device that employs a method of passive heat exchange based on natural convection, which circulates a fluid without the necessity of a mechanical pump. Thermosiphoning is used for circulation of liquids and volatile gases in heating and cooling applications such as heat pumps, water heaters, boilers and ...