Asian dust evens took place in Seoul on 27~28 March and 31 March~1 April 2007, during which the mass and chemical compositions of PM 10 were measured at urban area in Seoul, Korea. In conjunction with PM 10 compositions, the behaviors of gas precursors such as CO, O 3 , SO 2 , and NO 2 and meteorological parameters and air mass trajectories were thoroughly examined. The earlier case was a weak dust incidence which was characterized by elevated concentrations of CO, SO 2 and NO 2 as well as secondary aerosols. In contrast, the later showed the trait of the dust aerosols associated with high PM 10 mass and Ca 2+ + concentrations. In general, the fractions of ionic species against mass decreased with increase in dust loading. The ratios of SO 4 2-to NO 3 -and SO 2 to NO 2 were similar in temporal variations, suggesting the concentrations of secondary aerosols were sensitive to the level of precursor gases. In this study, Na + + and Cl -were also highly elevated during the heavy dust episode, which is thought to have originated from alkaline soils spreading through the northeast regions of China.

No abstract

No abstract

In the field of thermal energy, interest in carbon-free fuels, such as H 2 , is increasing to reduce greenhouse gas emissions; simultaneously, efforts are being made to reduce NO x emissions. In this study, experimental and numerical methodologies were applied to analyze the characteristics of flameless combustion under oxygen enrichment conditions for the simultaneous reduction of greenhouse gases and fine dust precursors. Flameless combustion was achieved under all conditions, and numerical simulations using GRI-mech 3.0

No abstract