Alkenes are oxidized rapidly in the atmosphere by addition of OH and subsequently O2 leading to the formation of β-hydroxy peroxy radicals. These peroxy radicals react with NO to form β-hydroxy nitrates with a branching ratio α. We quantify α for C2–C8 alkenes at 295 K± 3 and 993 hPa. The branching ratio can be expressed as α = (0.045± 0.016)×N−(0.11± 0.05)whereN is the number of heavy atoms (e...

Benzene is a solvent strictly related to some industrial activities and to automotive emissions. After the reduction in lead content of fuel gasoline, and the consequent decrease in octane number, an increase in benzene and other aromatic hydrocarbons in gasoline occurred. Therefore, an increase in the concentration of these chemicals in the air as primary pollutants and as precursors of photoc...

The conference, chaired by John T. Herron of the Chemical Kinetics Division of NIST, was attended by 240 scientists from 14 countlries representing academic, government and private sector institutions. Engineering Company. The range of the sponsors is indicative of the broad range of interests and applications which were the subjects of the conference. The conference followed the tradition of p...

Ozone, a highly reactive oxidant gas is a major component of photochemical smog. As an inhaled toxicant, ozone induces its adverse effects mainly on the lung. Inhalation of particulate matter has been reported to cause airway inflammation in humans and animals. Furthermore, epidemiological evidence has indicated that exposure to particulate matter (PM[2.5-10]), including diesel exhaust particle...

Small aldehydes are formed during the photochemical oxidation of many VOC’s, olefins and terpenes in urban as well as in rural areas. Photolysis and reaction with the OH radical are the most important initiation reactions for the removal of these compounds conducting to the formation of peroxy radicals and in the case of photolytic decomposition, either to stable molecules or free radicals. The...

Aerosol formation from ot-pinene and •-pinene was studied in a series of outdoor smog chamber experiments. Since a previous tudy focused on •-pinene (Pandis et al., 1991), more attention was given here to ot-pinene. The initial hydrocarbon and NO x concentrations ranged from 37 to 582 ppb and 31 to 380 ppb, respectively. The aerosol carbon yield, the fraction of the carbon initially present tha...

China has experienced very rapid economic development in recent yearsUrban air has very high concentrations of various pollutants, including sulphur dioxide (SO2), oxides of nitrogen (NOx), ozone (O3) and particulate. This paper reviews the changes in air quality in the cities like Guangzhou over the past 15 years, and notes that a serious vehicular-related emissions problem has been superimpos...

Diesel engines due to the better fuel economy have been widely used in automotive area. However, the limited reserve of fossil fuel and deteriorating environment have made scien‐ tists seek to alternative fuels for diesel while keeping the high efficiency of diesel engine. Fuel consumption is expected to increase from 86 million barrels per day to 112 million bar‐ rels per day by 2035 according...

[1] Nitrogen dioxide (NO2) is a key species in studying photochemical smog and formation mechanisms of nitrate in fine particles. However, the conventional commercially available chemiluminescence (CL)-based method often has uncertainties in measuring NO2 because of interferences with other reactive nitrogen species. In this study, an Aerodyne Cavity Attenuated Phase Shift Spectroscopy (CAPS) N...

Nitrous acid, a component of photochemical smog and a common indoor air pollutant, may reach levels of 100 ppb where gas stoves and unvented portable kerosene heaters are used. Nitrous acid is a primary product of combustion and may also be a secondary product by reaction of nitrogen dioxide with water. Because the usual assays for nitrogen dioxide measure several oxides of nitrogen (including ...