Major efforts to control motor vehicle emissions have been made in recent years, both through improved emission control technologies and through gasoline reformulation. Our assessment of the impacts of these efforts was conducted in the San Francisco Bay Area, in lanes of a highway tunnel where heavy-duty vehicles are not allowed. This study focuses on the afternoon rush hour, during which over...

Biodiesel is one of the most promising renewable, alternative and environmentally friendly biofuels that can be used in diesel engine without any need for any modification in the engine. However, researchers have reported that the engines running with biodiesel emit NOx in higher concentrations. To address this problem, in the present study an experimental investigation has been carried out on ...

A multivariable control scheme is designed to minimize emission of nitrogen oxides NOx and generation of smoke in a Diesel engine equipped with a variable geometry tur bocharger VGT and an external exhaust gas recirculation system EGR Steady state optimization results in operat ing points where NOx emissions and smoke generation are highly coupled and require joint management by VGT and EGR act...

[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...

Since the Euro-III standard was adopted, the main methods to inhibit NOx production in diesel engines are exhaust gas recirculation (EGR) and select catalyst reduction (SCR). On these methods SCR offers great fuel economy, so it has received wide attention. However, there also exists a trade-off law between NOx conversion efficiency and NH3 slip under dynamic conditions. To inhibit NH3 slip wit...

[1] In this work, we map and develop for the first time an independent satellite constrained NOx emission inventory for India for 2005 using an inverse technique and iterative procedure. We used OMI tropospheric NO2 column retrievals over the Indian region, with tropospheric NO2 columns simulated by the WRF‐Chem model using the INTEX‐B emission inventory. We determined the local relationship be...

For years economists have urged policymakers to use market-based approaches such as cap-and-trade programs or emission taxes to control pollution. The SO2 allowance market created by Title IV of the 1990 U.S. Clean Air Act Amendments represents the first real test of the wisdom of economists’ advice. Subsequent urban and regional applications of NOx emission allowance trading took shape in the ...

Within a urban context, the most important pollutants that should be studied and reduced in a urban context in order to ensure the sustainability of the metropolitan environment are NOx and PM10. While the emission factors for NOx are well known for all the sources, the PM emission from traffic are of two types, exhaust and nonexhaust. The latter type of emission is due to vehicle components’ w...