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.
BlueDEFâ¢ Diesel Exhaust Fluid is a key element of the Selective Catalytic Reduction (SCR) process used by many medium- and heavy-duty engine builders to meet EPA 2010 regulations. BlueDEF is a non-toxic solution of 67.5% purified water and 32.5% ultra-pure automotive-grade urea.