Definition of node. 1a : a pathological swelling or enlargement (as of a rheumatic joint)b : a discrete mass of one kind of tissue enclosed in tissue of a different kind.
Diesel exhaust fluid (DEF) from a separate tank is injected into the exhaust pipeline, where the aqueous urea vaporizes and decomposes to form ammonia and carbon dioxide. Within the SCR catalyst, the NO. x are catalytically reduced by the ammonia (NH. 3) into water ( H2O) and nitrogen (N.
After much anticipation in the market, John Deere today announced that it will add a diesel exhaust fluid (DEF) to its tractor engines to meet EPAâs Final Tier 4 emissions standards.The standards require an 80% reduction in nitrogen oxides over previous engine technologies.he engines will be ready for launch by the final Tier 4 deadline of 2013 for engines 74 hp and below and 2014-2015 for engines 75 hp and above. John Deere says the SCR system will be integrated in its current engine platform, which uses emissions technology called Exhaust Gas Recirculation (EGR) technology.