• Title/Summary/Keyword: Light Pollution

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Seismic Design of Prefabricated Light Weight Bridges (승용차 전용 조립식 고가도로의 내진설계 연구)

  • 강형택;박영하;김성훈;이일근
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2003.09a
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    • pp.288-294
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    • 2003

  • Increasing the volume of traffic on the roads causes social and economical problems such as increasing air-pollution and distribution cost. Prefabricated light weight bridge becomes a possible solution for these problems in the urban area where it is difficult to construct new one or expend the existing road. There are some merits in this kind of bridge. First, the design live and dead loads are minimized by allowing only passenger cars. Second employing prefabrication construction scheme reduces the construction time. Third, there is no need to buy land if the elevation road is placed on the top of existing one. In seismic design of bridges, base isolation has been an effective solution when the bridge has stiff piers and a heavy superstructure. The prefabricated light weight bridge has different dynamic characteristics from the ordinary bridges. In this paper, the applicability of base isolators such as lead rubber bearing and elastomeric bearing, to prefabricated light weight bridge is examined.

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A Study on Characteristics of Methane Emissions from Gasoline Passenger Cars (휘발유 자동차의 메탄(CH4) 배출특성에 관한 연구)

  • Jeon M.S.;Ryu J.H.;Lyu Y.S.;Kim J.C.;Lim C.S.;Kim D.W.;Jeong S.W.;Cho S.Y.
    • Journal of Korean Society for Atmospheric Environment
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    • v.21 no.6
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    • pp.649-655
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    • 2005

  • Automotive exhaust is suspected to be one of the main reasons of the rapid increase in greenhouse effect gases in ambient air. Although methane emissions are generally orders of magnitude lower than emissions of $CO_{2}$, the global warming potential (GWP) of methane is greater than that of $CO_{2}$. The environmental impact of methane emissions from vehicles is negligible and is likely to remain so for the foreseeable future. In this study, in order to investigate greenhouse gas emission characteristics from gasoline passenger cars, 20 vehicles were tested on the chassis dynamometer and methane emissions were measured. The emission characteristics by model year, mileage, vehicle speed were discussed. Test mode is CVS-15 mode that have been used to regulate for light-duty vehicle in Korea. It was found that $CH_{4}$ emissions showed higher for cold start, old model year and long mileage than hot start, new model year and short mileage, respectively. These results were compared with IPCC emission factors and the overall our results were anticipated to contribute for domestic greenhouse gas emissions calculation.

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