There have been a number of gasoline specifications that have changed or have been considered for change in the past few years. The most prominent of these changes has been summer volatility restrictions, wintertime oxygenated fuel requirements, and reformulated gasoline requirements which incorporate year-round oxygenate requirements and summertime emission requirements. For reasons described ...

This study deals with some methods of making human exposure estimates, aimed at describing the human exposure for selected air pollutants in Sweden that are suspected carcinogens. Nitrogen oxides (NOx) have been chosen as an indicator substance for estimating the concentration of the urban plume. Earlier investigations have shown that the traffic in Swedish cities contributes around 85% to the ...

Artificial Intelligence has been present since more than two decades ago, in the treatment of data concerning the protection of the environment; in particular, various groups of researchers have used genetic algorithms and artificial neural networks in the analysis of data related to the atmospheric sciences and the environment. However, in this kind of applications has been conspicuously absen...

In urban areas, emissions of air pollutants by anthropogenic processes such as traffic, industry, power plants and domestic heating systems are the main sources of pollution (Fenger, 1999). The massive growth in road traffic and in the use of fossil fuels during the last decades has changed the composition of urban air, increasing the frequency of pollution episodes and the number of cities exp...

A theory developed by scientists to study nitrogen oxides, NOx, production by solar proton events shows that the NOx production rate is approximately equal to the rate of production of ion pairs during the proton impact. Since the bulk of ionization in such events is produced by secondary electron impacts, the same concept is used here to study the NOx production in low pressure discharges, cor...

Environmental impact assessment of liquid rocket motor exhaust obtained due to mainly liquid propellant combustion have been highlighted. Exhaust product analysis has been carried out theoretically by computer software NASA CEC -71 to identify toxic emissions of rocket combustion. In the present study a high volume Air Samplers (APM-430) was deployed at predetermined locations near launch pad f...

Background and Objectives: Exhaled nitric oxide (NO) is decreased by smoking while oxides of nitrogen such as nitrites/nitrates (NOx) are increased. It was hypothesised that in vitro cigarette smoke extract (CSE) would either inhibit NO generation by increasing the NO synthase inhibitor, NG, NG-dimethyl-L-arginine (ADMA) or increase NOx levels via an oxidation pathway, which in turn could be in...

As more metropolitan areas approach " non-attainment " status for ozone, air pollution at airports is becoming an increasingly important topic. Most proposed emissions reduction strategies target passenger automobiles and airport ground service equipment (GSE). At many airports, the future growth in oxides of nitrogen (NOx) emissions from aircraft is likely to offset any reduction achieved from...

The nonlinear features of the relationships between concentrations of aerosol and volatile organic compounds (VOC) and nitrogen oxides (NOx) in urban environments are revealed directly from data of long-term routine measurements of NOx, VOC, and total suspended particulate matter (PM). The main idea of the method is development of special empirical models based on artificial neural networks. Th...

Selective catalytic reduction (SCR) is an emissions control technique that primarily reduces harmful emissions of oxides of nitrogen (NOx). To maintain SCR performance, catalyst layers maybe added, removed, or replaced to improve NOx reduction efficiency. To make these changes, power plants must be temporarily shut down, and SCR maintenance during scheduled power plant outages can be very expen...