• 제목/요약/키워드: Nitrogen dioxide($NO_2$)

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Tethersonde와 기상탑 관측 자료를 이용한 울산지역 야간 역전에 따른 대기오염도 변화와의 관계 (Nocturnal Inversion Layer observed by Tethersonde and AWS System and its Relation to Air Pollution at Ulsan)

  • 임윤규;김유근;오인보;송상근
    • 한국환경과학회지
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    • 제14권6호
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    • pp.555-563
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    • 2005
  • This study presents the characteristics of nocturnal inversion layer and their effect on the concentration variations of surface air pollutants using tethersonde and automatic weather station (AWS, 2 layer tower) system in Ulsan during 2003, The method for the distinction of inversion intensity was decided based on the sum of nocturnal temperature gradient. As the results, there was a close correlation (correlation coefficient of 0,76) between the maximum inversion height obtained from tethersonde and the sum of nocturnal temperature gradient. The air pollutant concentration was also directly proportional to the inversion intensity. When the inversion intensity was strong in the nighttime, ozone $(O_3)$ concentration was lower, while nitrogen dioxide $(NO_2)$ concentration was higher. The carbon monoxide (CO) concentration was gradually higher according to the nocturnal inversion intensity, whereas sulfur dioxide $(SO_2)$ concentration was relatively constant. In addition, we found that there was no correlation between the inversion intensity and TSP concentration.

Potential Exposure to RSP, $NO_2$ and VOCs for Taxi Professional Driver

  • Kim, Dae-Won;Lee, Jung-Eun;Son, Bu-Soon;Kim, Young-Hee;Yang, Won-Ho
    • 한국환경보건학회:학술대회논문집
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    • 한국환경보건학회 2005년도 국제학술대회
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    • pp.299-302
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    • 2005
  • Vehicle occupant exposure to air pollutants has been a subject of concern in recent years because of higher levels of air pollutants inside gasoline or diesel-using vehicle, comparing to the surrounding atmosphere. This study evaluated the potential exposure to respirable suspended particulate (RSP), nitrogen dioxide ($NO_2$) and volatile organic compounds (VOCs), comparing weekday (Monday and Thursday) and weekend (Saturday). Indoor mean concentrations of RSP inside vehicle were 51.2 $ug/m^3$ and 75.52 $ug/m^3$ in weekday and weekend, respectively. Measured indoor NO$_2$ concentrations were 14,8 ppb and 20.8 ppb, respectively. Benzene and toluene mean concentrations inside vehicle were 5.4${\pm}$2.4 ppb and 23.8${\pm}$33.8 ppb, respectively.

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자동차 선적작업장의 공기오염 실태조사 (Investigation into Air Pollution in Car Shipping Workshop in Pyeongtaek Port)

  • 김지호;원종욱;김치년;노재훈
    • 한국산업보건학회지
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    • 제16권1호
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    • pp.44-53
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    • 2006
  • This study purposed to investigate air pollution in car shipping yards and, for this purpose, we selected an outdoor open-air yard and an indoor ramp into the ship and measured the concentrations of sulfur dioxide, nitrogen dioxide, carbon monoxide, PM10, PM2.5 and heavy metals in the air. The results of this study are as follows. No significant difference was observed in temperature and humidity between the outdoor and indoor workshop, and the average air flow was 0.52 m/s in the indoor workshop, which is higher than 0.19 m/s in the outdoor workshop(p<0.01). The average concentrations of sulfur dioxide, nitrogen dioxide, carbon monoxide, PM10 and PM2.5 according to workplace were 0.03 ppm(${\pm}0.01$), 0.03 ppm(${\pm}0.01$), 0.46 ppm(${\pm}0.22$), $39.44{\mu}g/m^3$(${\pm}2.45$) and $5.45{\mu}g/m^3$(${\pm}1.15$) respectively in the outdoor workshop, and 0.15 ppm(${\pm}0.05$), 0.22 ppm(${\pm}0.06$), 8.85 ppm(${\pm}3.35$), $236.39{\mu}g/m^3$(${\pm}58.21$) and $152.43{\mu}g/m^3$(${\pm}35.42$) respectively in the indoor workshop. Thus, the concentrations of gaseous substances in the indoor workshop were 4.9-19.2 times higher than those in the outdoor workshop, and the concentrations of fine dusts were 5.9-27.9 times higher(p<0.01). In addition, according to the result of investigating pollutant concentrations according to displacement and the number of car loaded when shipping gasoline cars into the ship, no significant relation between the number of cars loaded and pollutants was observed in shipping passenger cars, but the concentrations of nitrogen dioxide and carbon monoxide got somewhat higher with the increase of the number of cars loaded(p<0.05). In addition, the concentrations of nitrogen dioxide, carbon monoxide, PM10 and PM2.5 in the air were significantly higher when shipping recreational vehicles, the displacement of which is larger than passenger cars, than when shipping passenger cars(p<0.01). On the other hand, the average heavy metal concentrations of the air in indoor workshop were: lead $-0.05{\mu}g/m^3$(${\pm}0.10$); chromium $-0.90{\mu}g/m^3$(${\pm}0.18$); zinc $-0.38{\mu}g/m^3$(${\pm}0.24$); copper $-0.18{\mu}g/m^3$(${\pm}0.22$); and manganese and cadmium not detected. In addition, the complaining rates of 'asthma,' a major symptom of chronic respiratory diseases, were 18.5% and 22.5% respectively in indoor workers and outdoor workers. Thus the rate was somewhat higher in indoor workers but the difference was not statistically significant. The complaining rates of 'chronic cough' and 'chronic phlegm' were very low and little different between indoor and outdoor workers. The results of this study show that the reason for the higher air pollution in indoor than in outdoor workshop is incomplete combustion of fuel due to sudden start and over-speed when cars are driven inside the ship. In order to prevent high air pollution, efficient management measures should be taken including the observance of the optimal speed, the improvement of old ships and the installation of efficient ventilation system.

Monte-Carlo 모의실험을 통한 부분 인구집단별 이산화질소와 오존의 노출 및 위해성 평가 (Exposure and Risk Assessment of Nitrogen Dioxide and Ozone for Sub-population Groups using Monte-Carlo Simulations)

  • 박진현;류현수;양소영;박윤경;허정;김은채;최영태;조만수;양원호
    • 한국환경보건학회지
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    • 제45권2호
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    • pp.113-125
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    • 2019
  • Objectives: Although the risk assessments for nitrogen dioxide ($NO_2$) and ozone ($O_3$) have been extensively studied, most of the existing risk assessments were limited mainly to indoor environments such as workplaces, schools, and multi-use facilities. Therefore, integrated risk assessment is needed to consider exposure in all microenvironments, including outdoors. The purpose of this study was to assess the differences in risk among sub-population groups according to time-activity patterns and reported concentrations, as well as the lifetime risk of Koreans. Methods: In this study, we estimated time-weighted average exposure concentrations of $NO_2$ and $O_3$ for preschool children, students, housewives, workers, and seniors using residential time and indoor concentrations (house, school or workplace, other), outdoors, and transport by meta-analysis method. The risk for $NO_2$ and $O_3$ were assessed by hazard quotient using reference concentrations 30 and 60 ppb, respectively. The risk assessments were conducted through 1,000,000 Monte-Carlo simulations for probabilistic analysis. Results: Preschool children, students, housewives, workers, and seniors spent 91.9, 86.0, 79.8, 82.2, and 77.3% of their day in a house, school, or workplace, respectively. The risk assessment for the lifetime of a housewife and a worker showed that 33.8 and 28.4% of hazard quotients of $NO_2$ exceed 1, respectively, and more than 99% of hazard quotient of $O_3$ were less than 1. Conclusions: The risk of $NO_2$ and $O_3$ by sub-population group and for the lifetime of housewives and workers were assessed. The risk for $NO_2$ was higher than for $O_3$ and showed a different risk by sub-population group. Both $NO_2$ and $O_3$ showed a higher risk for housewives than for workers. This study can be used as a basis for lifetime exposure and risk assessment for $NO_2$ and $O_3$.

건축물 내부 마감재인 합성목재별 연소가스 독성평가 (Toxicity Evaluation of the Combustion Products from Synthetic Wood as Internal Finish)

  • 김종북;이시영
    • 한국화재소방학회논문지
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    • 제30권2호
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    • pp.7-18
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    • 2016
  • 본 연구는 주택이나 창고 등의 내부 마감재로 사용하는 합성 목재의 연소 독성평가에 관한 것으로 SEM, 콘 칼로리미터, FTIR를 활용해 집성판, MDF, 미송합판, 코어합판, 나왕 방부목 5종의 재료별 연소가스 독성을 실험 및 분석하였다. 각 재료별 독성특성 중 나왕 방부목에서 이산화탄소($CO_2$)의 치사농도인 100,000 ppm을 2.5배 초과하는 256,965 ppm, 이산화황($SO_2$)의 치사농도인 400 ppm의 3.6배를 초과하는 1,475 ppm이 검출되었다. 집성판은 이산화질소($NO_2$)가 1,569 ppm으로 치사농도인 250 ppm의 6배가 측정되었고, 암모니아($NH_3$)는 MDF에서 치사농도 값인 750 ppm 대비 795 ppm이 측정되었다. 따라서 대부분의 건축 재료에서 인체에 치명적인 가스가 발생되는 것을 확인하였고, 향후 건축 재료의 위해성을 평가하기 위한 기초데이터로 활용하고자 한다.

이산화질소 다중측정을 이용한 실내공기의 환기량 밀 발생량 추정에 관한 연구 (A Study on Estimation on Air Exchange Rate and Source Strength in Indoor Air Using Multiple Measurements of Nitrogen Dioxide)

  • 양원호;이기영;정문호;정문식
    • 한국산업보건학회지
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    • 제10권1호
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    • pp.160-169
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    • 2000
  • Daily indoor and outdoor nitrogen dioxide ($NO_2$) concentration for 30 days were measured in 28 houses with questionnaire of housing characteristics in Brisbane, Australia. Using mass balance equation and regression analysis, penetration factors and source strength factors were calculated. The penetration factors of 27 houses except one house were between zero and 1, though penetration factor should be between zero and 1 by means of mass balance equation. Relationship between indoor and outdoor concentrations in each 27 house was calculated using regression analysis. According to the obtained linear regression equation, the slope means penetration factor and the intercept means source strength factor. Calculated mean and standard deviation of coefficients of determination ($R^2$) in electric and gas range houses were $0.70{\pm}0.13$ and $0.57{\pm}0.21$, respectively. The source strength factors were more than zero in 27 houses. Mean and standard deviation of slopes in electric and gas range houses were $0.65{\pm}0.18$ and $0.56{\pm}0.12$, respectively. Mean and standard deviation of intercepts in electric and gas range houses were $1.49{\pm}1.25$ and $5.77{\pm}3.55$, respectively. Air exchange rate and source strength were calculated from penetration factor and source strength factor, respectively. Geometric mean and standard deviation of calculated air exchange rates in 27 houses were $1.1/hr{\pm}1.5$. Presence of gas range was the most significant factor contributing to indoor $NO_2$ level in house characteristics (p=0.003). In gas range houses, source strengths ranged from 4.1 to $33.1cm^3/hr{\cdot}m^3$ with a mean $12.7cm^3/hr{\cdot}m^3$ and a standard deviation 9.8. The source strengths of gas range houses were significantly different from those of electric range houses by t-test (p<0.001)

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서산지역의 대기질 경년변화 특성에 관한 연구 (A Study on the Trends of Air Quality and Characteristics in Seosan Area of Korean Penninsula)

  • 손병현;박동소
    • 한국산학기술학회논문지
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    • 제9권3호
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    • pp.779-786
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    • 2008
  • 본 연구에서는 1998년부터 2006년까지 9년 동안의 서산 지역 대기오염물질 농도 변화 특성을 조사하였다. 조사 결과, 최근 3년 동안 CO와 $O_3$을 제외한 $SO_2,\;NO_2$ 및 PM-10은 농도 변화가 거의 없는 안정화 단계를 보였다. $NO_2$, CO 및 $SO_2$의 월평균농도 변화는 여름철에 감소하다. 겨울철에 증가하는 경향을 보였으며 $O_3$과 PM-10은 봄철에 높은 농도를 보이며, 강수가 집중되는 여름철에 가장 낮은 농도분포를 보였다. 2006년 12월까지 오존의 1시간 기준치인 0.1 ppm을 초과한 횟수는 동문동이 68회, 독곶리 93회였고 8시간 기준치인 0.06 ppm을 초과한 횟수는 동문동 210회, 독곶리 213회였다. 또한 미세먼지의 경우 24시간기준인 $150{\mu}g/m^3$을 초과한 횟수가 동문동 25회, 독곶리 54회로 나타났다.

충청남도 서산시 기온의 통계적 모형 연구 (Analysis of statistical models on temperature at the Seosan city in Korea)

  • 이훈자
    • Journal of the Korean Data and Information Science Society
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    • 제25권6호
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    • pp.1293-1300
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    • 2014
  • 기온의 변화는 국가 정책에 여러 가지 영향을 준다. 본 연구에서는 충청남도 서산시 2003년 ~ 2012년 기온을 주위에서 쉽게 구할 수 있는 기상자료, 온실가스자료, 대기자료를 이용하여 자기회귀오차 (autoregressive error)모형으로 월별과 계절별로 분석하였다. 기온을 위한 기상자료로는, 풍속, 강수량, 일사량, 운량, 습도를 사용했고, 온실가스자료는 이산화탄소 ($CO_2$), 메탄 ($CH_4$), 아산화질소 ($N_2O$), 염화불화탄소 ($CFC_{11}$), 대기자료는 미세먼지 ($PM_{10}$), 이산화황 ($SO_2$), 이산화질소 ($NO_2$), 오존 ($O_3$), 일산화탄소 (CO)를 사용하였다. 분석 결과, 자기회귀오차모형으로 월별 기온을 39%-63% 정도 설명할 수 있다.

Drop Tube Furnace에서 석탄의 순산소 연소 특성 (A Study on the Oxy-Combustion of the Coal in Drop Tube Furnace)

  • 노선아;윤진한;이정규;길상인;민태진;김상복;박인용;한방우;김진태
    • 청정기술
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    • 제27권4호
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    • pp.367-371
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    • 2021
  • 순산소 석탄 화력 발전 시스템은 CO2 가스 회수 및 저장 기술(CCS: carbon capture & storage)의 하나로 순산소와 재순환된 연소가스를 이용하여 석탄 연소를 수행하는 기술이다. 이는 이산화탄소와 질소가 혼합된 배출 가스를 생산하는 기존의 공기 연소 시스템과 달리 공기 중의 산소를 먼저 분리하여 생산된 순산소와 재순환된 연소 가스를 이용하여 석탄을 연소하면 이산화탄소와 질소를 분리하는 후처리 공정 없이 이산화탄소만으로 이루어진 배출 가스를 생성하여 이의 저장을 용이하게 하는 기술이다. 본 연구에서는 O2/CO2 혼합 모의 가스를 이용하여 순산소 연소 시 발생되는 대기오염물질인 NO, SO2의 생성 특성을 살펴보았다. 반응 온도를 900 ℃ ~ 1200 ℃, 산소 분율을 30% ~ 50%로 변화시키면서 실험한 결과 생성 가스 내 NO 및 SO2의 농도는 반응 온도와 산소 분율이 증가할수록 증가하는 현상을 나타내었으며 CO2의 분율도 증가하는 현상을 나타내었다. 순산소 연소에서 30% O2/CO2를 이용한 연소와 air 조건인 21% O2/N2 연소에서 NO 발생을 비교한 결과 양쪽 모두 반응 온도에 따라서 NO 발생이 증가하게 되며 순산소 연소 조건에서 air 연소에 비하여 약 40 ~ 80 ppm까지 NO 발생이 낮아지는 현상을 나타내었다.

Non-edible Vegetable Oils for Alternative Fuel in Compression Ignition Engines

  • No, Soo-Young
    • 한국분무공학회지
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    • 제14권2호
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    • pp.49-58
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    • 2009
  • Non-edible vegetable oils instead of edible vegetable oils as a substitute for diesel fuel are getting a renewed attention because of global reduction of green house gases and concerns for long-term food and energy security. Out of various non-edible vegetable oils, karanja, mahua, linseed, rubber seed and cotton seed oils are selected in this study. A brief review of recent works related to the application of the above five vegetable oils and its derivatives in CI engines is presented. The production technologies of biodiesel based on non-edible vegetable oils are introduced. Problems in vegetable oil or biodiesel fuelled CI engine are included. In addition, future works related to spray characteristics of non-edible vegetable oil or biodiesel from it are discussed. The biodiesel fuel, irrespective of the feedstock used, results in a decrease in the emission of hydrocardon (HC), carbon monoxide (CO), particulate matter (PM) and sulphur dioxide ($SO_2$). It is also said to be carbon neutral as it contributes no net carbon dioxide to the atmosphere. Only oxides of nitrogen (NOx) are reported to increase which is due to oxygen content in the biodiesel fuel. The systematic assessment of spray char-acteristics of neat vegetable oils and its blends, neat biodiesel and its blends f3r use as diesel engine fuels is required.

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