• 제목/요약/키워드: air-spring

검색결과 840건 처리시간 0.031초

都市大氣의 水銀動態와 影響因子에 關한 硏究 (Study on the Behavior of Gaseous Mercury and its Influencing Factors in Urban AMbient Air)

  • 김민영;박상현;박성배
    • 한국대기환경학회지
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    • 제5권1호
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    • pp.11-21
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    • 1989
  • Atmospheric gaseous mercury was automatically measured by a mercury air monitor (Mercury monitor AM-1). The sample air was led to a scrubber and washed with buffer solution, and mercury was trapped with gold coated chromosorb P(AW) was successively eluted by heating the chromosorb and then detected by the cold vapor atomic absorption spectrophotometry. $SO_2, TSP, NO_x, CO, THC$. and some of meteorological factors were also measured simultaneously with mercury. A significant correlation between the concentration of mercury and those of 2,513 measurements, gaseous mercury concentration ranged from 4.73 to 112.8 $ng/m^3$ with an annual mean of 14.7$ng/m^3$ in urban area. At this place there was a clear seasonal variation with a maximuminDecember-January and aminimum in March-June. A secondary maximum existed in August to September. THe seasonal variation was found that the gaseous mercury in ambient air has a tendency to become low in spring and high in winter. Namely, the average of concentration in winter was about two times, 19.2 $ng/m^3$, higher than that in spring. In Seoul mercury levels on some months mainly Septermber-October increase with increasing relative humidity of the atmosphere. In Olympic park air levels were 8.2 (range 4.4-23.7)$ng/m^3$ with an coefficients of variation of 0.34 and in Seoul sports complex those were 7.7 (rnage 4.4-25.5) $ng/m^3$ with an coefficients of variation of 0.38 within the Seoul olympiad holding period of time. A significant diurnal mercury variation occurs both at the measuring sites and in the period of observation.

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오염물질기준지수(Pollutant Standards Index)를 이용한 대기질의 평가 -서울특별시 대기오염도에 대하여- (An Assessment of Air Pollution using Pollutant Standards Index (PSI) : $1983{\sim}1984$ in Seoul)

  • 정용;장재연;권숙표
    • Journal of Preventive Medicine and Public Health
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    • 제19권1호
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    • pp.65-75
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    • 1986
  • In order to assess the general health effect due to air pollution and to determine the critical pollutant which is meant by the worst effect to health among various pollutants in Seoul, air quality measurements at 10 sites during $1983{\sim}1984$ were analyzed using Pollutant Standards Index(PSI) : This index has been ultimately proposed to describe the comprehensive degree of the air pollution by U.S. Environmental Protection Agency(EPA) since 1976. Total average of PSI in Seoul during the two years was 139 that is described in 'unhealthful' The highest PSI appeared in Winter 183 through the 2 years, the lowest in Summer 99, and Spring 129 and Fall 150 respectively, PSI in Deungchon dong and Seongsu dong which are industrial areas were very high in terms of 'very unhealthful', while shinlim dong was shown in low in terms of 'good'. TSP was a priority pollutant in Seoul as the most frequently occuring critical pollutant. Its frequency was 76.4% in Spring, 86.0% in Summer, 78.0% in Fall and 44.2% in Winter during the 2 years. In Winter, $TSP{\times}SO_2$ was an important term as the critical pollutant in Seoul. Oxidant was the most frequently occuring critical pollutant in Kwangwhamoon through the whole seasons. It was recommended that the PSI could be used to assess the air pollution administratively and legally in context with publich health.

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남극 브랜스필드 해협에서의 퇴적과정과 관련된 기후특성 (Climatic Characteristics Related with Sedimentary Process in Bransfield Strait, Antarctica)

  • 이방용;권태영;이정순;윤호일;윤영준
    • 지구물리
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    • 제8권4호
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    • pp.173-185
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    • 2005
  • This study examines the relationships among sea ice concentration, surface air temperature, surface wind, and SST (Sea Surface Temperature) in Bransfield Strait to understand the climatic characteristics and its related sedimentary process there. In analyses of the monthly data, during the austral autumn (Mar., Apr., and May), the frequency of southeasterlies is correlated positively with the sea ice concentration and negatively with the surface air temperature, whereas that of northwesterlies is reverse. These relationships are explained by the process that the southeasterlies of the cold air from the Antarctic Continent affect the ocean current around Bransfield Strait. And then the ocean current makes the sea ice generated in the Weddell Sea drift into the strait. During the spring (Sep., Oct., and Nov.), sea ice concentration and surface air perature are closely correlated with the frequency of northwesterlies with warm air mass. In the some parts of the northern boundary region, the sea ice concentration in Bransfield Strait is positively correlated with the SST during the autumn and spring. Such relationship may rather propel the sea ice melting in proportion to the sea ice concentration during the autumn.

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냉기침강효과를 고려한 복잡지형의 최저기온 분포 추정 (Minimum Temperature Mapping in Complex Terrain Considering Cold Air Drainage)

  • 정유란;서형호;황규홍;황범석;윤진일
    • 한국농림기상학회지
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    • 제4권3호
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    • pp.133-140
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    • 2002
  • Site-specific minimum temperature forecasts are critical in a short-term decision making procedure for preventive measures as well as a long-term strategy such as site selection in fruits industry. Nocturnal cold air pools frequently termed in mountainous areas under anticyclonic systems are very dangerous to the flowering buds in spring over Korea, but the spatial resolution to detect them exceeds the current weather forecast scale. To supplement the insufficient spatial resolution of official forecasts, we developed a GIS - assisted frost risk assesment scheme for using in mountainous areas. Daily minimum temperature data were obtained from 6 sites located in a 2.1 by 2.1 km area with complex topography near the southern edge of Sobaek mountains during radiative cooling nights in spring 2001. A digital elevation model with a 10 m spatial resolution was prepared for the entire study area and the cold air inflow was simulated for each grid cell by counting the number of surrounding cells coming into the processing cell. Primitive temperature surfaces were prepared for the corresponding dates by interpolating the Korea Meteorological Administration's automated observational data with the lapse rate correction. The cell temperature values corresponding to the 6 observation sites were extracted from the primitive temperature surface, and subtracted from the observed values to obtain the estimation error. The errors were regressed to the flow accumulation at the corresponding cells, delineating a statistically significant relationship. When we applied this relationship to the primitive temperature surfaces of frost nights during April 2002, there was a good agreement with the observations, showing a feasibility of site-specific frost warning system development in mountainous areas.

외기 도입에 따른 바닥급기 시스템의 에너지 사용량 분석 (Analysis of the Energy Consumption in Underfloor Air Distribution System depending on Outdoor Air Intake Rates)

  • 김동희;허정호;조동우;유기형;유지용
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2006년도 하계학술발표대회 논문집
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    • pp.826-831
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    • 2006
  • In this paper, we discussed the energy performance of underfloor air distribution(UFAD) and overhead air distribution system according to outdoor air intake rates in a office building. For this, the laboratory(S lab.) is selected for measuring the thermal environments of UFAD system and overhead system. Based on the measured data, the TRNSYS simulation is used to evaluate the energy performance of UFAD system and the overhead system according to outdoor air intake rates. By increasing outdoor air intake rates from required outdoor air intake rates(100CMH) to maximum air intake rates, the energy savings of UFAD system comparing with overhead system are varied $15%{\sim}25.6%$ in summer, $12.8%{\sim}19%$ in fall/spring and not varied in winter(8%). As results of simulations on stratification height and cooling set temperature, the lower the stratification height and the higher cooling set temperature, the larger cooling energy savings of UFAD comparing with overhead system according to outdoor air intake rates.

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미기상학적 기법을 이용한 난지도 매립지에서 VOCs의 Air/Soil 교환량 측정 (Micrometeorological measurements of VOC fluxes from Nan-Ji-Do landfill area during Spring 2000)

  • 김민영;김기현;이강웅
    • 한국대기환경학회:학술대회논문집
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    • 한국대기환경학회 2000년도 추계학술대회 논문집
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    • pp.76-77
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    • 2000
  • 최근 들어 대도시와 그 주변지역을 중심으로 빈번하게 발생하는 광화학적 오염에 VOCs가 기여하는 바가 크다는 것은 주지의 사실이다. VOCs가 이와 같은 국지적인 광화학적 오염에 지대한 영향을 줄뿐만 아니라 지역 규모에서도 대기 중의 화학적인 조성과 산화력을 결정하고 있어서 이들의 발생, 화학적 변환, 소멸에 따른 기작과 동태를 규명하는 것이 대기 화학에서 중요한 부분으로 생각되고 있다. (중략)

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침실의 가구배치 패턴별 실내 기류 분석 (Flue analysis of indoor air by furniture arrangement pattern in bedroom)

  • 유복희
    • 한국주거학회:학술대회논문집
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    • 한국주거학회 2001년도 학술발표대회논문집
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    • pp.113-117
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    • 2001
  • This study aims to analyze the relation between furniture arrangement and ventilation. In this study, the furniture layout of students'bedroom have been classified three kinds of patterns so that the air flue of the rooms can be analyzed. According to the results of the study, it is showed that the furniture arrangements have influenced the ventilation efficiency and it has been recognized that space plan needs the applicable study.

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상전도 흡인식 자기부상열차 분기기 주행시의 부상공극변동과 분기기 거더의 진동 특성 (Vibration characteristics between levitation air-gap and switching system girders)

  • 신현재;이종민;최장영
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 춘계학술대회 논문집
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    • pp.824-829
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    • 2011
  • EMS-type Maglev vehicle maintains constant levitation air-gap between electromagnet and guideway by using gap sensor. The other words, when Maglev vehicles levitating over the guideway, mass of the vehicle effects through 1st (electromagnetic air-gap control) and 2nd (air-spring) suspension to grider. Resonace between electromagnetic suspension and grider could be occurred, which causes instability and poor ridecomfort. This paper is to test the dymanic interaction between levitation air-gap and switching system grider that has less mass and high natural frequencies than other type of general girders.

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현장실험을 통한 공동주택의 실내공기환경 평가 (A Evaluation Study on Indoor Air Quality of the Apartment House through Field Measurement)

  • 박용승;배상환;유복희;홍천화
    • 한국주거학회:학술대회논문집
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    • 한국주거학회 2003년도 정기총회 및 추계학술대회
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    • pp.83-87
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    • 2003
  • In recent days, IAQ(Indoor Air Quality) is regarded as one of the most important environmental factors as well as thermal and acoustic comfort. Various architectural materials are applied and air-tightness of the building is more strengthening to save energy consumption. This is why the air quality of the newly built houses became worse. In this study, contaminants(CO, CO$_2$, Radon, TVOCs, HCHO) density was measured in a newly built house and evaluation was carried out by ASHRAE and EPA Standards. As a result, CO, CO$_2$, TSP and Radon density of the newly built house was in a range of ASHRAE and EPA Standards, but it turned out TVOCs and HCHO density exceeds almost 3${\sim}$5 times in comparison with that of ASHRAE and EPA Standards.

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