scholarly journals Characterization of the vehicle emissions in the Greater Taipei Area through vision-based traffic analysis system and its impacts on urban air quality

2021 ◽  
Vol 782 ◽  
pp. 146571
Author(s):  
I-Chun Tsai ◽  
Chen-Ying Lee ◽  
Shih-Chun Candice Lung ◽  
Chih-Wen Su
Keyword(s):  
Air Quality ◽  
Vehicle Emissions ◽  
Traffic Analysis ◽  
Urban Air Quality ◽  
Urban Air ◽  
Analysis System

Biofuels, vehicle emissions, and urban air quality

2016 ◽  
Vol 189 ◽  
pp. 121-136 ◽  
Author(s):  
Timothy J. Wallington ◽  
James E. Anderson ◽  
Eric M. Kurtz ◽  
Paul J. Tennison
Keyword(s):  
Air Quality ◽  
Vehicle Emissions ◽  
Urban Air Quality ◽  
Biodiesel Fuel ◽  
Urban Air ◽  
Mobile Source ◽  
Engine Calibration ◽  
Diesel Vehicles ◽  
Light Duty Vehicles ◽  
The Impact

Increased biofuel content in automotive fuels impacts vehicle tailpipe emissions via two mechanisms: fuel chemistry and engine calibration. Fuel chemistry effects are generally well recognized, while engine calibration effects are not. It is important that investigations of the impact of biofuels on vehicle emissions consider the impact of engine calibration effects and are conducted using vehicles designed to operate using such fuels. We report the results of emission measurements from a Ford F-350 fueled with either fossil diesel or a biodiesel surrogate (butyl nonanoate) and demonstrate the critical influence of engine calibration on NOx emissions. Using the production calibration the emissions of NOx were higher with the biodiesel fuel. Using an adjusted calibration (maintaining equivalent exhaust oxygen concentration to that of the fossil diesel at the same conditions by adjusting injected fuel quantities) the emissions of NOx were unchanged, or lower, with biodiesel fuel. For ethanol, a review of the literature data addressing the impact of ethanol blend levels (E0–E85) on emissions from gasoline light-duty vehicles in the U.S. is presented. The available data suggest that emissions of NOx, non-methane hydrocarbons, particulate matter (PM), and mobile source air toxics (compounds known, or suspected, to cause serious health impacts) from modern gasoline and diesel vehicles are not adversely affected by increased biofuel content over the range for which the vehicles are designed to operate. Future increases in biofuel content when accomplished in concert with changes in engine design and calibration for new vehicles should not result in problematic increases in emissions impacting urban air quality and may in fact facilitate future required emissions reductions. A systems perspective (fuel and vehicle) is needed to fully understand, and optimize, the benefits of biofuels when blended into gasoline and diesel.

Characterization of urban air quality using GIS as a management system

2003 ◽  
Vol 122 (1) ◽  
pp. 105-117 ◽  
Author(s):  
E. Puliafito ◽  
M. Guevara ◽  
C. Puliafito
Keyword(s):  
Air Quality ◽  
Management System ◽  
Urban Air Quality ◽  
Urban Air

Use of infrared and ultraviolet spectrometers to measure the effect of vehicle emissions on urban air quality

1995 ◽  
Author(s):  
Dan Gibbs ◽  
Christopher L. Betty ◽  
Mohsen Dolaty ◽  
Vittorio Argento
Keyword(s):  
Air Quality ◽  
Vehicle Emissions ◽  
Urban Air Quality ◽  
Urban Air

scholarly journals APFoam-1.0: integrated CFD simulation of O<sub>3</sub>–NO<sub>x</sub>–VOCs chemistry and pollutant dispersion in typical street canyon

2020 ◽  
Author(s):  
Luolin Wu ◽  
Jian Hang ◽  
Xuemei Wang ◽  
Min Shao ◽  
Cheng Gong
Keyword(s):  
Air Quality ◽  
Street Canyon ◽  
Vehicle Emissions ◽  
Cfd Simulation ◽  
Pollutant Dispersion ◽  
Urban Air Quality ◽  
Urban Air ◽  
License Plate ◽  
Health And Economic Development ◽  
Reactive Pollutant

Abstract. Urban air quality issues are closely related to the human health and economic development. In order to improve the resolution and numerical accuracy of urban air quality simulation, this study has developed the Atmospheric Photolysis calculation framework (APFoam-1.0), an open-source CFD code based on OpenFOAM, which can be used to examine the micro-scale reactive pollutant formation and dispersion in the urban area. The chemistry module of the newly APFoam has been modified by adding five new types of reaction, which implements the coupling with atmospheric photochemical mechanism (full O3–NOx–VOCs chemistry) and CFD model. Additionally, numerical model has been validated and shows the good agreement with wind tunnel experimental data, indicating that the APFoam has sufficient ability to study urban turbulence and pollutant dispersion characteristics. By applying the APFoam, O3–NOx–VOCs formation processes and dispersion of the reactive pollutants are analyzed in an example of typical street canyon (aspect ratio H / W = 1). Chemistry mechanism comparison shows that O3 and NO2 are underestimated while NO is overestimated if the VOCs reactions are not considered in the simulation. Moreover, model sensitivity cases reveal that 82 %–98 % and 75 %–90 % of NO and NO2 are related to the local vehicle emissions which are verified as the dominated contributors to local reactive pollutant concentration in contrast to their background conditions. Besides, a large amount of NOx emission, especially NO emission, is beneficial to reduce the O3 concentrations since NO consumes O3. Background precursors (NOx/VOCs) from boundary conditions only contribute 2 %–16 % and 12 %–24 % of NO and NO2 concentrations and raise O3 concentration by 5 %–9 %. Weaker ventilation conditions lead to accumulation of NOx and higher NOx concentration, but a lower O3 concentrations due to the stronger NO titration effect consuming O3. Furthermore, in order to reduce the reactive pollutant concentrations under the odd-even license plate policy (reduce 50 % of the total vehicle emissions), vehicle VOCs emissions should be reduced by at least another 30 % to effectively lower O3, NO and NO2 concentrations at the same time. These results indicate that the examination of the precursors (NOx/VOCs) from both traffic emissions and background boundaries is the key point for better understanding O3–NOx–VOCs chemistry mechanisms in street canyons and providing effective guidelines for the joint prevention and control of local street air pollution.

aiRe - A web-based R application for simple, accessible and repeatable analysis of urban air quality data

2021 ◽  
Vol 138 ◽  
pp. 104976
Author(s):  
Juan José Díaz ◽  
Ivan Mura ◽  
Juan Felipe Franco ◽  
Raha Akhavan-Tabatabaei
Keyword(s):  
Air Quality ◽  
Urban Air Quality ◽  
Quality Data ◽  
Urban Air ◽  
Web Based ◽  
Air Quality Data
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