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.
ABOUT THE PROGRAM. ASTMâs Diesel Exhaust Fluid (DEF) Proficiency Testing Program provides laboratories with a statistical quality assurance (SQA) tool, enabling labs to compare, improve, and maintain a high level of performance in the use of ISO methods with other laboratories worldwide.