• 한국지리정보학회지
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• 제14권2호
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• pp.109-127
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• 2011

대기 에어러솔은 대기중에 존재하는 미세입자로 인체 유해성을 지니고 있으며 기후변화에 있어서도 중요한 역할을 하는 변수로 알려져 있다. 게다가 대기 에어러솔의 주요 성분에 대한 정확한 평가는 환경에 미치는 영향에 있어서도 매우 중요하다. 이 때문에 지구관측 위성자료는 대기질 감시측면에서도 효과적인 수단으로 이용되고 있다. 따라서 본 연구에서는 인공위성 관측 자료를 이용하여 전구적인 규모의 대기 에어러솔의 주요 성분별 분포변화를 알아보고자 MODIS 에어러솔 광학두께(AOT; Aerosol Optical Thickness)와 미세입자분율(FMF; Fine Mode Fraction), 그리고 TOMS 자외선 흡수성 에어러솔 지수(AAI; UV Absorbing Aerosol Index)를 이용하여 네 가지의 주요 에어러솔의 성분(먼지, 탄소성, 황산화물, 해염)을 구분할 수 있는 방법을 제시하였다. 여기서 얻어진 결과물을 검증하기 위하여 에어러솔 예측 모델자료와 각 격자별 자료로 선형회귀분석을 수행한 결과, 본 연구에서 산출된 결과물이 에어러솔의 성분별 전반적인 패턴을 잘 표현하는 것을 확인 할 수 있었다. 이렇게 주요 에어러솔 타입으로 구분된 위성자료의 사용은 대기질 감시뿐만 아니라 기후변화연구에 있어서도 도움을 줄 것으로 사료된다.

• 한국환경과학회지
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• 제28권1호
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• pp.107-123
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• 2019

The aerosol chemical components in $PM_{2.5}$ in several regions (Seoul, Busan, Daejeon, and Jeju Island) were investigated with regard to their concentration characteristics and optical properties. The optical properties of the various aerosol components (e.g., water-soluble, insoluble, Black Carbon (BC), and sea-salt) were estimated using hourly and daily aerosol sampling data from the study area via a modeling approach. Overall, the water-soluble component was predominant over all other components in terms of concentration and impact on optical properties (except for the absorption coefficient of BC). The annual mean concentration and Aerosol Optical Ddepth (AOD) of the water-soluble component were highest in Seoul (at the Gwangjin site) ($26{\mu}g/m^3$ and 0.29 in 2013, respectively). Further, despite relatively moderate BC concentrations, the annual mean absorption coefficient of BC ($21.7Mm^{-1}$) was highest in Busan (at the Yeonsan site) in 2013, due to the strong light absorbing ability of BC. In addition, high AODs for the water-soluble component were observed most frequently in spring and/or winter at most of the study sites, while low values were noted in summer and/or early fall. The diurnal variation in the AOD of each component in Seoul (at the Gwangjin site) was slightly high in the morning and low in the afternoon during the study period; however, such distinctions were not apparent in Jeju Island (at the Aweol site), except for a slightly high AOD of the water-soluble component in the morning (08:00 LST). The monthly and diurnal differences in the AOD values for each component could be attributed to the differences in their mass concentrations and Relative Humidities (RH). In a sensitivity test, the AODs estimated under RH conditions of 80 and 90% were factors of 1.2 and 1.7 higher, respectively, than the values estimated using the observed RH.

• Environmental Engineering Research
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• 제24권1호
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• pp.159-172
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• 2019

To investigate the influence of pollution events on the chemical composition and formation processes of aerosol particles, 24-h integrated size-segregated particulate matter (PM) was collected during the fall season at an urban site of Gwangju, Korea and was used to determine the concentrations of mass, water-soluble organic carbon (WSOC) and ionic species. Furthermore, black carbon (BC) concentrations were observed with an aethalometer. The entire sampling period was classified into four periods, i.e., typical, pollution event I, pollution event II, and an Asian dust event. Stable meteorological conditions (e.g., low wind speed, high surface pressure, and high relative humidity) observed during the two pollution events led to accumulation of aerosol particles and increased formation of secondary organic and inorganic aerosol species, thus causing $PM_{2.5}$ increase. Furthermore, these stable conditions resulted in the predominant condensation or droplet mode size distributions of PM, WSOC, $NO_3{^-}$, and $SO{_4}^{2-}$. However, difference in the accumulation mode size distributions of secondary water-soluble species between pollution events I and II could be attributed to the difference in transport pathways of air masses from high-pollution regions and the formation processes for the secondary chemical species. The average absorption ${\AA}ngstr{\ddot{o}}m$ exponent ($AAE_{370-950}$) for 370-950 nm wavelengths > 1.0 indicates that the BC particles from traffic emissions were likely mixed with light absorbing brown carbon (BrC) from biomass burning (BB) emissions. It was found that light absorption by BrC in the near UV range was affected by both secondary organic aerosol and BB emissions. Overall, the pollution events observed during fall at the study site can be due to the synergy of unfavorable meteorological conditions, enhanced secondary formation, local emissions, and long-range transportation of air masses from upwind polluted areas.

• Asian Journal of Atmospheric Environment
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• 제4권3호
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• pp.115-140
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• 2010

Great concerns about atmospheric aerosols are attributed to their multiple roles to atmospheric processes. For example, atmospheric aerosols influence global climate, directly by scattering or absorbing solar radiations and indirectly by serving as cloud condensation nuclei. They also have a significant impact on human health and visibility. Many of these effects depend on the size and composition of atmospheric aerosols, and thus detailed information on the physicochemical properties and the distribution of airborne particles is critical to accurately predict their impact on the Earth's climate as well as human health. A single particle analysis technique, named low-Z particle electron probe X-ray microanalysis (low-Z particle EPMA) that can determine the concentration of low-Z elements such as carbon, nitrogen and oxygen in a microscopic volume has been developed. The capability of quantitative analysis of low-Z elements in individual particle allows the characterization of especially important atmospheric particles such as sulfates, nitrates, ammonium, and carbonaceous particles. Furthermore, the diversity and the complicated heterogeneity of atmospheric particles in chemical compositions can be investigated in detail. In this review, the development and methodology of low-Z particle EPMA for the analysis of atmospheric aerosols are introduced. Also, its typical applications for the characterization of various atmospheric particles, i.e., on the chemical compositions, morphologies, the size segregated distributions, and the origins of Asian dust, urban aerosols, indoor aerosols in underground subway station, and Arctic aerosols, are illustrated.

• 한국입자에어로졸학회지
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• 제9권3호
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• pp.163-171
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• 2013

Soot particles emitted from combustion processes are often coated by non-absorbing organic materials, which enhance the global warming effect of soot particles. It is of importance to study the condensation characteristics of soot particles experimentally and theoretically to reduce the uncertainty of the climate impact of soot particles. In this study, the condensational growth of soot particles in a tubular coater was modeled by a one-dimensional (1D) plug flow model and a two-dimensional (2D) laminar flow model. The effects of 2D heat and mass transports on the predicted particle growth were investigated. The temperature and coating material vapor concentration distributions in radial direction, which the 1D model could not accounted for, affected substantially the particle growth in the coater. Under the simulated conditions, the differences between the temperatures and vapor concentrations near the wall and at the tube center were large. The neglect of these variations by the 1D model resulted in a large error in modeling the mass transfer and aerosol dynamics occurring in the coater. The 1D model predicted the average temperature and vapor concentration quite accurately but overestimated the average diameter of the growing particles considerably. At the outermost grid, at which condensation begins earliest due to the lowest temperature and saturation vapor concentration, condensing vapor was exhausted rapidly because of the competition between condensations on the wall and on the particle surface, decreasing the growth rate. At the center of the tube, on the other hand, the growth rate was low due to high temperature and saturation vapor concentration. The effects of Brownian diffusion and thermophoresis were not high enough to transport the coating material vapor quickly from the tube center to the wall. The 1D model based on perfect radial mixing could not take into account this phenomenon, resulting in a much higher growth rate than what the 2D model predicted. The result of this study indicates that contrary to a previous report for a thermodenuder, 2D heat and mass transports must be taken into account to model accurately the condensational particle growth in a coater.

• 대기
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• 제23권1호
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• pp.85-92
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• 2013

2001년 4월 제주 고산기후관측소에서 AERONET sun/sky radiometer와 MPL을 통해 관측된 에어로졸 광학적 두께, 단산란 알베도, 비대칭 변수, 에어로졸 소산계수 프로파일 등을 대기복사모델의 입력 자료로 이용하여 대기가열효과를 산정하고, 이들 광학변수가 대기복사가열률에 미치는 영향을 분석하였다. 본 연구에서는 NCAR Climate Community Model (CCM-3.6)에 포함되어 있는 복사 모듈인 Column Radiation Model (CRM-2.1.2)을 연직 54층으로, AERONET sun/sky radiometer로부터 관측된 4 파장 (440, 670, 870, 그리고 1020 nm)에서의 관측 자료를 19개의 파장에서 계산 가능하도록 수정하였다. 에어로졸층이 존재하지 않은 맑은 날 (4월 14일과 16일)은 지표면과 대기상단에서의 에어로졸 직접복사강제력이 각각 $-20{\sim}-25\;W\;m^{-2}$와 $-10{\sim}-15\;W\;m^{-2}$로, 대기 중 흡수는 $+10{\sim}+15\;W\;m^{-2}$였다. 에어로졸층이 관측된 4월 15일과 4월 17~18일의 경우 지표면, 대기, 대기상단의 에어로졸 복사강제력이 맑은 날에 비해 3~4배 정도 크게 나타났다. 4월 14일과 16일에의 대기복사가열률 (${\Delta}H$)는 $1{\sim}2\;K\;day^{-1}$ 범위에서 산출되었으며, 4월 15일과 4월 17~18일에는 MPL 관측에서 보여지는 에어로졸층에서의 ${\Delta}H$와 ${\Delta}H_{aerosol}$가 각각 $3\;K\;day^{-1}$ 이상과 $1{\sim}3\;K\;day^{-1}$ 범위에서 산정되었다. 에어로졸 광학적 두께와 비대칭 변수의 변화에 따른 에어로졸층의 ${\Delta}H$ 변화는 미미하였으나, 단산란 알베도의 10% 변화는 지표면과 대기상단에서의 에어로졸 직접복사강제력의 30%, 대기복사강제력의 약 60%, 그리고 에어로졸층 ${\Delta}H$의 약 35% 변화를 유발하였다. 이는 에어로졸 광학적 두께 10% 변화와 비교하여 대기흡수 또는 에어로졸층의 가열 및 냉각 효과가 6배 가량 큰 결과로, 태양복사를 효과적으로 잘 흡수하는 에어로졸의 양에 의해 대기 가열 또는 ${\Delta}H$가 크게 좌우됨을 의미한다. 2001년 4월부터 2008년 3월까지 제주 고산기후관측소에서의 AERONET sun/sky radiometer 관측 자료를 이용하여 계산한 ${\Delta}H$와 ${\Delta}H_{aerosol}$의 월변화를 보면, ${\Delta}H$는 4~8월 사이에 대류권 하부에서 약 $1.0\;K\;day^{-1}$ 이상으로 뚜렷하게 나타났으나, ${\Delta}H_{aerosol}$의 경우 2월부터 6월까지 고도 2 km 이하에서 약 $0.8\;K\;day^{-1}$ 이하의 범위에서 나타나는데, 이는 대부분의 에어로졸이 지표면 부근의 대기경계층에 존재하며, 봄철 황사와 오염 에어로졸의 증가에 의한 영향으로 판단된다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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• pp.342-347
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• 2011

Solar energy is attenuated by absorbing gases (ozone, aerosol, water vapour and mixed gas) and cloud in the atmosphere. And these are measured with solar instruments (pyranometer, phyheliometer). However, solar energy is insufficient to represent detailed energy distribution, because the distributions of instruments are limited on spatial. If input data of solar radiation model is accurate, the solar energy reaches at the surface can be calculated accurately. Recently a variety of satellite measurements are available to TERA/AQUA (MODIS), AURA (OMI) and geostationary satellites (GMS-5, GOES-9, MTSAT-1R, MTSAT-2 and COMS). Input data of solar radiation model can be used aerosols and surface albedo of MODIS, total ozone amount of OMI and cloud fraction of meteorological geostationary satellite. The solar energy reaches to the surface is calculated hourly by solar radiation model and those are accumulated monthly and annual. And these results are verified the spatial distribution and validated with ground observations.

• 한국대기환경학회지
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• 제22권6호
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• pp.863-875
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• 2006

Intensive visibility monitoring was conducted to investigate physical and chemical characteristics of visibility impairment by airborne pollen. Light attenuation coefficients were optically measured by a transmissometer, a nephelometer, and an aethalometer. Elemental, ionic, and carbonaceous species were chemically analyzed on the filters collected by $PM_{2.5}$ and $PM_{10}$ samplers. Aerosol size distribution was analyzed using a cascade impactor during airborne pollen period. Airborne pollen count was calculated using a scanning electron microscope. Airborne pollen was emitted into the atmosphere in springtime and funker degraded visibility through its scattering and absorbing the light. Average light extinction coefficient was measured to be $211{\pm}36Mm^{-1}$ when airborne pollen was not observed. But it increased to $459{\pm}267Mm^{-1}$ during the airborne pollen period due to increase of average $PM_{2.5}$ and $PM_{10}$ mass concentration and relative humidity and airborne pollen count concentration for $PM_{10}$, which were measured to be $46.5{\pm}29.1{\mu}g\;m^{-3},\;97.0{\pm}41.7{\mu}g\;m^{-3},\;54.1{\pm}11.6%$, and $68.2{\pm}89.7m^{-3}$, respectively. Average light extinction efficiencies for $PM_{2.5}$ and $PM_{10}$ were calculated to be $5.9{\pm}0.9$ and $4.5{\pm}0.8m^2 g^{-1}$ during the airborne pollen period. Light extinction efficiency for $PM_{10}$ increased further than that for $PM_{2.5}$. The average light extinction budget by airborne pollen was estimated to be about 24% out of the average measured light extinction coefficient during the airborne pollen period.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2003년도 추계국제학술대회
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• pp.182-182
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• 2003

1.연구목적 : Cr $O_3$은 금속 도금용, 페인트 둥에 많이 사용되며 독성이 강하여 그동안 근로자 건강장해 및 직업병 사례가 많이 발생하였다. 그러나 산화크롬의 흡입에 의한 연구자료는 매우 부족하다. 이에 흡입챔버를 이용 Rats에 흡입노출을 통하여 유해성을 평가하고 각 장기에 흡수되는 크롬의 농도평가와 회복기간에 따라 각 장기별로 흡수된 크롬의 소실속도 둥을 연구하였으며 더불어 회복기간과 제거율의 상관관계 및 체내 반감기 등을 연구하였다. 2. 연구방법 : Cr $O_3$를 폐내 침착율 및 흡수율이 높은 0.5～5$\mu\textrm{m}$ 크기의 aerosol형태로 SD Rats 수컷에 전신폭로 하였다. 노출농도는 0.00, 0.20, 0.50, 1.25mg/㎥(Cr)으로 하여 1일 6시간, 주 5일, 13주간 반복 노출하였고 회복군은 시험물질 종료일을 기준으로 2주, 8주 경과 후 조직장기와 전혈, 혈장 및 적혈구내, 뇨 중 각각의 크롬농도를 분석하였으며 혈액 및 혈액 생화학적 검사도 병행하였다 3. 연구결과 : 혈액검사에서 0.20, 0.50 mg/㎥ 농도군 실험동물의 RBC와 HGB, HCT 둥은 감소의 경향을 보였으나 농도 의존적이지는 않았다. 신장의 절대중량은 대조군에 비해 유의하게 (p<0.05) 감소하고 폐장의 경우는 대조군에 비해 유의한(p<0.05) 절대중량 증가를 보였다 시험물질 노출 후 혈액 중 전혈, 혈장, 적혈구의 회복기간(x)별 크롬농도(y)의 소실속도 상관계수 (노출농도 0.50mg/㎥군의 경우)는 y = 66.51 $e^{0.057}$x/, y = 67.2 $e^{0.101}$x/, y = 70.01 $e^{0.030}$x/, 반감기는 12.0, 6.86, 23.0 일이고 폐장, 간장, 신장의 회복기간(x)별 크롬농도(y)의 소실속도 상관계수 (노출농도 0.50 mg/㎥군의 경우)는 y = 1808 $e^{0.004}$93x/, y = 12.02 $e^{0.029}$7x/, y = 67.61 $e^{0.029}$2x/ 반감기는 140.6, 23.3, 23.7 일로 평가되었다. 4. 고찰 : 실험동물의 전혈, 혈청, 뇨에서의 크롬농도와 시험물질 노출농도는 밀접한 상관을 가졌으나 농도에 정비례하지는 않았다. 뇨 중 흡수된 크롬의 경우 회복기간 초기 (12시간 내)에 대부분 배설이 일어나는 것으로 나타났다. 폐장이 간장, 신장 등 다른 장기에 비해 높은 축적량을 보였으며 축적된 크롬농도가 높을수록 크롬의 소실속도는 현저히 저하하는 경향을 보였다. 노출농도가 높을수록 각 장기조직 내 크롬의 소실속도 (clearance)는 크게 감소경향이 있었으며 이는 체내 과부하시 자정작용이 감소하는 것으로 판단되었다. 본 연구 결과 SD rat를 이용 반복흡입노출의 경우 생체의 무유해영향농도 (NOAEL)는 0.2mg/㎥이하이며 발암물질을 감안하여 안전계수를 100으로 할 경우 사람에 대한 NOAEL은 0.002mg/㎥이하로 판단되었다. 특히 호흡기와 폐장에 강한 유해성을 나타내는 것으로 확인되었다. 것으로 확인되었다.