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NOx
About: NOx is a research topic. Over the lifetime, 26367 publications have been published within this topic receiving 496555 citations.
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TL;DR: In this paper, the relationship between ambient concentrations of NO, nitrogen dioxide (NO 2 ), ozone (O 3 ) and nitrogen oxides (NO x =NO+NO 2 ) is analyzed.
166 citations
TL;DR: In this article, a 4-cylinder direct-injection diesel engine using ultralow sulfur diesel blended with ethanol, biodiesel and diglyme was investigated to investigate the particulate emissions of the engine under five engine loads at the engine speed of 1800rpm.
166 citations
TL;DR: In this paper, the potential of burning and reforming ammonia as a carbon-free fuel in production of hydrogen, fundamental unstretched laminar burning velocities, and flame response to stretch were studied both experimentally and computationally.
166 citations
University of Wollongong1, Harvard University2, Princeton University3, National Oceanic and Atmospheric Administration4, California Institute of Technology5, University of California, Davis6, University of Maryland, Baltimore County7, University of California, Berkeley8, Cooperative Institute for Research in Environmental Sciences9, University of Colorado Boulder10, Purdue University11, University of California, Irvine12, Goddard Space Flight Center13, University of Innsbruck14, University of Oslo15
TL;DR: A new BVOC oxidation mechanism (including updated isoprene chemistry, new monoterpene chemistry, and particle uptake of RONO2) is implemented in the GEOS-Chem global chemical transport model with ∼25 × 25 km2 resolution over North America to evaluate the model using aircraft and ground-based observations from the Southeast US in summer 2013.
Abstract: . Formation of organic nitrates (RONO2) during oxidation of biogenic volatile organic compounds (BVOCs: isoprene, monoterpenes) is a significant loss pathway for atmospheric nitrogen oxide radicals (NOx), but the chemistry of RONO2 formation and degradation remains uncertain. Here we implement a new BVOC oxidation mechanism (including updated isoprene chemistry, new monoterpene chemistry, and particle uptake of RONO2) in the GEOS-Chem global chemical transport model with ∼ 25 × 25 km2 resolution over North America. We evaluate the model using aircraft (SEAC4RS) and ground-based (SOAS) observations of NOx, BVOCs, and RONO2 from the Southeast US in summer 2013. The updated simulation successfully reproduces the concentrations of individual gas- and particle-phase RONO2 species measured during the campaigns. Gas-phase isoprene nitrates account for 25–50 % of observed RONO2 in surface air, and we find that another 10 % is contributed by gas-phase monoterpene nitrates. Observations in the free troposphere show an important contribution from long-lived nitrates derived from anthropogenic VOCs. During both campaigns, at least 10 % of observed boundary layer RONO2 were in the particle phase. We find that aerosol uptake followed by hydrolysis to HNO3 accounts for 60 % of simulated gas-phase RONO2 loss in the boundary layer. Other losses are 20 % by photolysis to recycle NOx and 15 % by dry deposition. RONO2 production accounts for 20 % of the net regional NOx sink in the Southeast US in summer, limited by the spatial segregation between BVOC and NOx emissions. This segregation implies that RONO2 production will remain a minor sink for NOx in the Southeast US in the future even as NOx emissions continue to decline.
166 citations
TL;DR: In this article, an overall experimental investigation on NOx emission based on combustion characteristics of biodiesel has been carried out, and a little decrease in NOx emissions was observed at low loads under low and medium engine speeds.
166 citations