44 / | HD | FUEL AND RELATED COMPOSITIONS |
300 | DF | LIQUID FUELS (EXCLUDING FUELS THAT ARE EXCLUSIVELY MIXTURES OF LIQUID HYDROCARBONS) {31} |
329 | DF | .~ Heterocyclic carbon compound containing a hetero ring having chalcogen or nitrogen as the only ring hetero atoms {6} |
340 | DF | .~.~ The hetero ring contains five members including nitrogen and carbon (e.g., pyrrolidones, porphines, etc.) {4} |
346 | .~.~.~ Polymeric or copolymeric compound having plural occurrences of the hetero ring (e.g., alpha-olefin maleimide copolymers, etc.) |