Nitrogen oxides (NOx) and black carbon (BC) emission factors (EF) of 440 on-road diesel trucks were determined by conducting on-road chasing studies in Beijing and Chongqing, China, in the winter 2010. NOx and BC EF distributions are reported. The median NOx EFs for trucks sampled on level roads in Chongqing and Beijing are 40.0 and 47.4 g kg-fuel 1, respectively. The median BC EFs are 1.1 and ...

The major pollutants from diesel engines are NOx and soot. NOx and soot emissions are of concerns to the international community. They have been judged to pose a lung cancer hazard for humans as well as elevating the risk of non-cancer respiratory ailments. These emissions react in the atmosphere in the presence of sunlight to form ground-level ozone. Ground-level ozone is a major component of ...

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...

As precursors to tropospheric ozone and nitrate, nitrogen oxide (NOx) in the present atmosphere and its transformation in response to emission and climate perturbations are studied by using the CAM-Chem model and air quality measurements from the National Emissions Inventory (NEI), Clean Air Status and Trends Network (CASTNET), and Environmental Protection Agency Air Quality System (EPA AQS). I...

● Deactivation of Diesel Catalyst Abstract: The first diesel catalysts, introduced in 1970s for underground mining applications, were simple oxidation catalysts designed for conversion of CO and HC. These catalysts gradually evolved into the modern diesel oxidation catalysts, optimized for PM emission reduction. Future requirements for NOx emission reduction from diesel engines call for new cat...

In this study, the effects of hydrogen and hydroxygen additions and oxygen enrichment on the emission characteristics of a gasoline engine (EF7) were investigated and compared with each other. The simulation was launched by GT-Power at different engine speeds with 5 % to 15 % volume fractions for both of oxygen and hydrogen enrichment and 4.5 % to 9 % volume fractions of hydroxygen addition in ...

In this paper, we examine the changes in ambient ozone concentrations simulated by the Community Multiscale Air Quality (CMAQ) model for summer 2002 under three different nitrogen oxides (NOx) emission scenarios. Two emission scenarios represent best estimates of 2002 and 2004 emissions; they allow assessment of the impact of the NOx emissions reductions imposed on the utility sector by the NOx...

The emission characteristics of mobile sources in the Mexico City Metropolitan Area (MCMA) have changed significantly over the past few decades in response to emission control policies, advancements in vehicle technologies and improvements in fuel quality, among others. Along with these changes, concurrent non-linear changes in photochemical levels and criteria pollutants have been observed, pr...

this study was focused on measuring air pollutants emission from factories producing the asphalt related products in delijan industrial estate, which is the main center of asphalt related products in iran. emissions of four factories were analyzed for air pollutants using a stack analyzer, testo 360, testo co., and germany. the average concentration of all measured stacks for pm, thc, co, nox, ...

Anthropogenic emissions of air pollutants in China influence not only local and regional environments but also the global atmospheric environment; therefore, it is important to understand how China’s air pollutant emissions will change and how they will affect regional air quality in the future. Emission scenarios in 2020 were projected using forecasts of energy consumption and emission control...