Abstract: A system for treatment of exhaust emissions from a compression-ignited internal combustion engine comprises (A) a superatmospheric-pressurized source of gaseous oxygen, (B) an inlet for the gaseous oxygen of component (A) where the exhaust emissions from the engine flow past the inlet and form a mixture with the gaseous oxygen from the inlet, and (C) a diesel particulate filter or catalyzed diesel particulate filter through which the mixture of engine exhaust emissions and gaseous oxygen flows, where the oxygen content of the mixture is greater than the oxygen content of the exhaust emissions from the engine. A method for improving the performance of a diesel particulate filter or catalyzed diesel particulate filter in a compression-ignited internal combustion engine comprises operating the engine and treating the exhaust emissions from the engine with the exhaust emissions treatment system.

Abstract: Apparatus is provided which permits highly accurate remote measurement of methane gas concentrations even in daylight through the use of an extremely narrow spectral filter centered on the Q-branch of the methane absorption band at 3.3 microns and through the use of cooperating comparison channels with digital processing for real time correction of data to compensate for surface temperature, atmospheric temperature and atmospheric water absorption factors.