Nitrogen oxides (NOx) contribute to a wide range of environmental effects including the formation of acid rain and destroy ozone layer. In-cylinder high temperature flame and high oxygen concentration are the parameters which affect the NOx emissions. The EGR system is a very effective way for reducing NOx emission from a diesel engine (via reduction of these parameters), particularly at the...

The e€ect of present-day and future NOx emissions from aircraft on the NOx and ozone concentrations in the atmosphere and the corresponding radiative forcing were studied using a three-dimensional chemistry transport model (CTM) and a radiative model. The e€ects of the aircraft emissions were compared with the e€ects of the three most important anthropogenic NOx surface sources: road trac, ele...

23 Anthropogenic emissions of nitrogen oxides (NOx ≡ NO + NO2) and carbon monoxide (CO) 24 affect particulate matter (PM) air quality on an intercontinental scale by changing background 25 concentrations of oxidants (OH, ozone, H2O2) and thus increasing the oxidation rate of sulfur 26 dioxide (SO2) to sulfate and NOx to nitrate. We conduct sensitivity simulations with the GEOS27 Chem chemical t...

A mobile laboratory was used to measure onroad vehicle emission ratios during the MCMA-2003 field campaign held during the spring of 2003 in the Mexico City Metropolitan Area (MCMA). The measured emission ratios represent a sample of emissions of in-use vehicles under real world driving conditions for the MCMA. From the relative amounts of NOx and selected VOC’s sampled, the results indicate th...

Recent measurements in Houston show that HONO traffic emissions are 1.7 % of NOx emissions, which is about twice the previously estimated value of 0.8 % based on tunnel measurements in 2001. The 0.8 % value is widely used to estimate mobile emissions of HONO for air quality modeling applications. This study applies the newly estimated HONO / NOx ratio in the WRF–SMOKE–CMAQ modeling system and e...

The possibility of using electricity dispatching strategies to achieve a 50% nitrogen oxide (NOx) emission reduction from electricity generating units was examined using the grid of the Electricity Reliability Council of Texas as a case study. Simulations of a hypothetical policy demonstrate that imposing higher NOx prices induces a switch from some coal-fired generation to natural gas generati...

PA Rule Targets Smokestack Pollution In July 2011 the U.S. EPA finalized the CrossState Air Pollution Rule to reduce SO2 and NOX emissions from power plants using available emissions control technologies. SO2 and NOX contribute to ground-level ozone and fine particle pollution and often cross state lines, ending up far from their provenance. The rule is projected to achieve up to $280 billion i...

[1] Surface NOx emissions are estimated by a combined assimilation of satellite observations of NO2, CO, O3, and HNO3 with a global chemical transport model. The assimilation of measurements for species other than NO2 provides additional constraints on the NOx emissions by adjusting the concentrations of the species affecting the NOx chemistry and leads to changes in the regional monthly-mean e...

[1] Assimilated inversion on a daily basis using OMI tropospheric NO2 columns is developed and applied in a regional chemical transport model (REAM) to constrain fossil fuel (FF) NOx emissions over east Asia in 2007. The iterative nature of the assimilated inversion improves upon the widely used monthly-mean inversion by accounting for the chemical feedbacks of changed NOx emissions and reducin...

Biodiesel fuels have the potential to become a reliable substitute for diesel which is used moderately to meet the current energy demands. This fuel can be produced from new or used vegetable oils, non-edible sources and animal fats, which are non-toxic, biodegradable and renewable. In spite of the many advantages of using biodiesel, most of the researchers have reported that they produce highe...