Various engine and shock tube studies have observed increased NOx emissions from the combustion of biodiesels relative to regular diesel and linked them to the degree of unsaturation or the number of double bonds in the molecular structure of long-chain biodiesel fuels. We report herein a numerical investigation on the structure and emission characteristics of triple flames burning n-heptane an...

Current atmospheric models do not include secondary organic aerosol (SOA) production from gas-phase reactions of polycyclic aromatic hydrocarbons (PAHs). Recent studies have shown that primary emissions undergo oxidation in the gas phase, leading to SOA formation. This opens the possibility that low-volatility gas-phase precursors are a potentially large source of SOA. In this work, SOA formati...

Secondary organic aerosol (SOA) formation from atmospheric oxidation of isoprene has been the subject of multiple studies in recent years; however, reactions of other conjugated dienes emitted from anthropogenic sources remain poorly understood. SOA formation from the photooxidation of isoprene, isoprene-1-13C, 1,3butadiene, and 2,3-dimethyl-1,3-butadiene is investigated for high NOx conditions...

Pollutant emissions from combustion systems are a major area of concern with today’s energy needs. Numerical simulations have helped with the design of clean and efficient combustion strategies over the years. However, with the emergence of new fuels and combustion modes, it is necessary to improve the computational models. In this research, improved NOx and soot models are developed which uses...

Introduction NOx Storage-Reduction (NSR) catalytic systems and urea-SCR are both considered viable solutions for the NOx removal under lean conditions. In NSR systems (e.g. PtBa/Al2O3) the removal of NOx is realized under cyclic conditions, by alternating long lean periods during which NOx are adsorbed on the catalyst with short excursions under rich conditions during which the stored NOx are r...

This study is focused on the effects of nitrogen content in biomass feedstock on the producer gas composition and the flue gas NOx emissions from a pilot-scale gasification and combustion system. Biomass gasification has the potential to produce carbon negative energy by using renewable resources. The greenhouse gases emitted by burning fossil fuels have to be reduced, and biomass gasification ...

NADPH oxidases (NOXs) represent the only known dedicated source of reactive oxygen species (ROS) and thus a prime therapeutic target. Type 4 NOX is unique as it produces H2O2, is constitutively active, and has been suggested to localize to cardiac mitochondria, thus possibly linking mitochondrial and NOX-derived ROS formation. The aim of this study was to identify NOX4-binding proteins and exam...

Paulot et al. (Reports, 7 August 2009, p. 730) reported that the photooxidation of isoprene under low-nitrogen oxides (NOx) conditions produces epoxides that can facilitate the formation of secondary organic aerosol (SOA). However, another pathway involving the formation of methyl-butenediol intermediates can also lead to isoprene-derived SOA formation. Further research is needed to clarify the...

There is a growing body of evidence to suggest that reactive oxidant species (ROS) including O2-, OH- or H2O2 act as second messengers to activate platelets via 1) calcium mobilisation, 2) nitric oxide (NO) inactivation, and 3) interaction with arachidonic to give formation of isoprostanes. Among the enzymes generating ROS formation NOX2, the catalytic core of NADPH oxidase (NOX), plays a promi...

In contrast with the textbook view of remote chemistry where HNO3 formation is the primary sink of nitrogen oxides, recent theoretical analyses show that formation of RONO2 (6ANs) from isoprene and other terpene precursors is the primary net chemical loss of nitrogen oxides over the remote continents where the concentration of nitrogen oxides is low. This then increases the prominence of questi...