• Title/Summary/Keyword: Aerosol distributions

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The Development of the Solar-Meteorological Resources Map based on Satellite data on Korean Peninsula (위성자료기반의 한반도 태양기상자원지도 개발)

  • Jee, Joon-Bum;Choi, Young-Jean;Lee, Kyu-Tae
    • 한국태양에너지학회:학술대회논문집
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    • 2011.11a
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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.

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The Analyses of Causes of Visibility Impairment in Pusan (부산지역 시정악화의 원인 분석)

  • Kim Yoo-Keun;Moon Yun-Seob;Bae Joo-Hyun;Kwak Jin
    • Journal of Environmental Science International
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    • v.8 no.6
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    • pp.639-643
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    • 1999
  • After analyzing the correlation between air pollution and visibility, TSP and $NO_2$ is responsible for poor visibility in Pusan. After analyzing the correlation between meteorological factors and visibility, general pattern of humidity has clear negative correlation. The variation of wind speed has a positive correlation. In order to investigate the cause of poor visibility in Pusan area, the Andersen sampler and PM-2.5 are used to collect and analyze aerosol. This study was carried out to monitor the visibility using Forward scattering meter and to find out the characteristics and the cause of good visibility case and poor visibility case by measuring and analyzing a variety of parameters, such as particle size distributions, chemical compositions, and meteorological conditions in Pusan. According to the analysis of intensive sampling, $NO_3^-,NH_4^+$ ion concentration increased together with the mass concentration around $0.5\~2.5{\mu}m$ approximately during the case of poor visibility. $NH_4NO_3,\;NH_4Cl,\;and\;NaCl$ were thought to be the major components of fine particles.

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Development and performance evaluation of the porous tube dilutor for real-time measurements of fine particles from high humidity environments (고수분 환경에서 미세먼지 실시간 측정을 위한 다공 튜브형 희석장치의 개발 및 성능 평가)

  • Woo, Chang Gyu;Hong, Ki-Jung;Kim, Hak-Joon;Kim, Yong-Jin;Han, Bangwoo;An, Jeongeun;Kang, Su Ji;Chun, Sung-Nam
    • Particle and aerosol research
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    • v.13 no.3
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    • pp.105-110
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    • 2017
  • Real-time measurements of fine particles from stack emission gases are necessary due to the needs of continuous environmental monitoring of PM10 and PM2.5. The porous tube dilutor using hot and cold dilutions was developed to measure fine particles without condensable particles from highly humid emission gases and compared to the commercialized ejector-type dilutor. Particle size distributions were measured at the emission gases from a diesel engine and a coal-fired boiler. The porous tube dilutor could successfully measure the accumulation mode particles including relatively large particles more than $3{\mu}m$ without nuclei particles, while the ejector dilutor detected some condensable particles and could not detect large particles. The porous tube dilutor could successfully remove the already condensed water droplet particles generated by a humidifier in a $30m^3$ chamber.

Size Distributions of Trace Elements in Airborn Particulates Collected using Drum impactor at Gosan, Jeju Island : Measurements in Springtime 2002 (DRUM impactor를 이용한 대기 입자상 물질 중 원소성분의 입경분포 특성 : 제주도 고산지역의 2002년 봄철 (3.29-5.30) 측정 연구)

  • 한진석;문광주;류성윤;안준영;공부주;홍유덕;김영준
    • Journal of Korean Society for Atmospheric Environment
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    • v.20 no.4
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    • pp.555-569
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    • 2004
  • Size -segregated measurements of aerosol composition using 8-stage DRUM impactor are used to determine the transport of natural and anthropogenic aerosols at Gosan site from 29 March to 30 May in 2002. Separation of ambient aerosols by DRUM impactor offers many Advantages over other standard filtration techniques. Some of the most important advantages are the ability to segregate into details by particle tire, to better preserve chemical integrity since the air stream doesn't pars through the deposit, to collect samples as a function of time, and to have a wide variety of impaction surfaces available to match analytical needs. Although the transport of Yellow sand is a well-known phenomenon in springtime, the result of measurement shows that not only soil dust but also anthropogenic aerosols, including sulfur, enriched trace metals such as Pb, Ni, Zn. Cu, Cr, As, Se, Br, are transported to Gosan in springtime. This study combines the size- and time-resolved aerosol composition measurements with isentropic, backward air-mass trajectories in order to identify some potential source regions of anthropogenic aerosols. As a result, during the NYS period, the average concentration of PM$_{10}$ was 46$\mu\textrm{g}$/㎥, Si, Al. S, Fe, Cl, K, Ca were higher than 1,000 ng/㎥ and Ti was about 100 ng/㎥. The concentrations of Zn, Mn, Cu. Pb, Br, Rb, V, Cr, Ni. At, Se ranged between 1 and 70 ng/㎥. More than 50% typical soil elements, tuck as Al, Si, Fe, Cd. Ti, Cr, Cu, Br. were distributed in a coarse particle range(5.0-12${\mu}{\textrm}{m}$). In other hand, anthropogenic pollutants, luck as S, N, Vi, were mainly distributed in a fine particle range (0.09-0.56${\mu}{\textrm}{m}$). During the YS period, PM$_{10}$ increased about 8 times than NYS period, and main soil elements, such as Al, Si, S, K, V, Mn, Fe also doubled in coarse particle range (1.15-12${\mu}{\textrm}{m}$). But Zn, As, Pb, Cu and Se, which distributed in the time aerosols (0.09-0.56${\mu}{\textrm}{m}$), were on the same level with or decreased than NYS period. Finally. except the YS Period, coarse particles (2.5-12${\mu}{\textrm}{m}$) are inferred to be influenced by soil, coal combustion, waste incineration, ferrous and nonferrous sources through similar pathways with Yellow Sand. But fine particles have different sources, such as coal combustion, gasoline vehicle, biomass burning, oil or coal combustion, nonferrous and ferrous metal sources, which are transported from China, Korea peninsula and local sources.ces.

Preparation of TiO2 Nanoparticles from Titanium Tetraisopropoxide Using an Aerosol Microreactor (에어로졸 마이크로반응기에 의한 Titanium Tetraisopropoxide로부터 TiO2 나노입자 제조)

  • Choi, Jae Gil;Park, Kyun Young
    • Korean Chemical Engineering Research
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    • v.43 no.5
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    • pp.609-615
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    • 2005
  • $TiO_2$ particles, 30-300 nm in diameter, were prepared by thermal decomposition of titanium tetraisopropoxide (TTIP) using an aerosol microreactor, by which about $1{\mu}l$ of the liquid precursor is injected into an evaporator, 1 cc in volume, and vaporized precursor is then transported by nitrogen as a bolus to a tubular reactor 4 mm in diameter and 35 cm in length. Investigated were the effects of the reactor temperature and the concentration of TTIP vapor on the morphology, particle size distribution and crystalline structure of produced $TiO_2$ particles. With TTIP vapor concentration kept constant at 1 mol%, the reactor temperature was varied from 300 to 500 and $700^{\circ}C$. The primary particle size decreased with increasing the temperature, and the size distributions were mono-modal at 300 and $500^{\circ}C$, but bi-modal at $700^{\circ}C$. The TTIP vapor concentration was increased from 1 to 3.5 and 7 mol%, holding the reactor temperature at $700^{\circ}C$. The bi-modal distribution seen at the concentration of 1 mol% disappeared and the number of particles composing an agglomerate increased at the higher concentrations. These effects of the reactor temperature and the precursor concentration were discussed in comparison with experimental results reported earlier.

Characteristics of Ambient Metals: Size Segregated Ambient Concentrations and Dry Deposition Fluxes at Four Sites in Kunpo in 2000

  • Kim, Yong-Pyo;Yun, Hui-Jung;Yi, Seung-Muk
    • Journal of Korean Society for Atmospheric Environment
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    • v.18 no.E2
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    • pp.57-68
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    • 2002
  • Atmospheric dry deposition fluxes and size segregated concentrations of particulate metal elements were measured at four sites in Kunpo, a small city in the Seoul metropolitan area in Korea. At each site, aerosol samples were collected by dry deposition plates, a cascade impactor, and a coarse panicle rotary impactor during four sampling periods. At all sites, the average fluxes of metals measured during daytime were higher than nighttime fluxes due to higher wind speeds and higher ambient concentrations during daytime. The average fluxes of crustal elements (Al, Ca) were 1∼2 orders of magnitude higher than anthropogenic elements (As, Cd, Cu, Mn, Ni, Pb, and Zn). The daytime fluxes of Al and Ca were between 90 and 12000 $\mu\textrm{g}$ m$\^$-2/ day$\^$-1/, and the nighttime fluxes of Al and Ca were between 20 and 2200 $\mu\textrm{g}$ m$\^$-2/ day$\^$-1/. The daytime fluxes of Pb, a typical anthropogenic element, were between 20 and 160$\mu\textrm{g}$ m$\^$-2/ day$\^$-1/, and the nighttime fluxes of Pb were between ND and 100$\mu\textrm{g}$ m$\^$-2/ day$\^$-1/. Also the ambient metal concentrations during daytime were higher than nighttime. Based on a dust emission estimation study in Kunpo, it was found that dust emissions during daytime are higher than nighttime. The concentrations of crustal elements were higher than anthropogenic elements. The distributions of heavy metals were mainly in small particles (D$\_$p/ 9㎛). The fraction of crustal elements in the large particles (D$\_$p/> 9㎛) were higher than anthropogenic elements.

Condensation and coagulation of metallic species with fly ash particles in a waste incinerator (폐기물 소각시 생성되는 유해 중금속물질과 연소실내 비산재와의 응축, 응집 현상에 대한 연구)

  • Yu, Ju-Hyeon;Hwang, Jeong-Ho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.2
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    • pp.264-274
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    • 1997
  • A numerical analysis on condensation and coagulation of the metallic species with fly ash particles pre-existing in an incinerator was performed. Waste was simplified as a mixture of methane, chlorine, and small amounts of Pb and Sn. Vapor-phase amounts of Pb- and Sn -compounds were first calculated assuming a thermodynamic equilibrium state. Then theories on vapor-to-particle conversion, vapor condensation onto the fly ash particles, and particle-particle interaction were examined and incorporated into equations of aerosol dynamics and vapor continuity. It was assumed that the particles followed a log-normal size distribution and thus a moment model was developed in order to predict the particle concentration and the particle size distribution simultaneously. Distributions of metallic vapor concentration (or vapor pressure) were also obtained. Temperature drop rate of combustion gas, fly ash concentration and its size were selected as parameters influencing the discharged amount of metallic species. In general, the coagulation between the newly formed metal particles and the fly ash particles was much greater than that between the metal particles themselves or between the fly ash particles themselves. It was also found that the amount of metallic species discharged into the atmosphere was increased due to coagulation. While most of PbO vapors produced from the combustion were eliminated due to combined effect of condensation and coagulation, the highly volatile species, PbCl$_{2}$ and SnCl$_{4}$ vapors tended to discharge into the atmosphere without experiencing either the condensation or the coagulation. For Sn vapors the tendency was between that of PbO vapors and that of PbCl$_{2}$ or SnCl$_{4}$. To restrain the discharged amount of hazardous metallic species, the coagulation should be restrained, the number concentration and the size of pre-existing fly ash particles should be increased, and the temperature drop rate of combustion gas should be kept low.

Seasonal Variation of Size Distributions of Polycyclic Aromatic Hydrocarbons in Air Particulates (대기 부유분진중 다환방향족 탄화수오류의 계절적 입경농도 분포 변이)

  • Chung, Yong;Park, Seong-Eun;Hwang, Man-Sik
    • Journal of Korean Society for Atmospheric Environment
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    • v.14 no.6
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    • pp.577-588
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    • 1998
  • Polycyclic aromatic hydrocarbons (PAHs) are products of incomplete combustion and, in urban area atmosphere, are mainly traffic or heating in origin. Size-segregated aerosol samples were collected on the Eixth story of Shinchon on the Yonsei campus, using a high-volume cascade impactor, between August 1994 and September 1995. Ten PAHs were analyzed by GC/MSD. The size distribution of PAH-containing particulates followed approximately a log-normal relationship with the majority of PAH content associated with particles below 3.0mm. PAHs concentration in submicron particles increased during the winter months. The Mass Median Diameter (MMD) value of annual particulates in the heavy traffic area of Shinchon shows about 1.6 pm. The MMD values of air particulate in winter were the lowest values and similar to that in summer, while MMD values of seasonal PAHs were generally lower than 1.0 pm. Among the PAHs, MMD values of PAHs with the more than 5 benzen ring were averagely lower than those with 4 benzin rings. Especially MMD's of dibenzo (a, h) anthracene in winter was clearly lower than in summer. This reason may be caused by fuels used for heating. In this area, 50∼80% PAHs mass was particles smaller than 1.0mm aerodynamic diameter in size range, and the MMD values of PAHs lower than those of other country's area.

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Comparison of Ultrafine Particles Monitored at a Roadside Using an SMPS and a TR-DMPS (SMPS와 TR-DMPS를 이용한 도로변 초미세 입자 모니터링 결과의 비교)

  • Woo, Dae-Kwang;Lee, Seung-Bok;Bae, Gwi-Nam;Kim, Tae-Sung
    • Journal of Korean Society for Atmospheric Environment
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    • v.24 no.4
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    • pp.404-414
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    • 2008
  • A Transient Differential Mobility Particle Spectrometer (TR-DMPS) with a short response time was recently developed to monitor high concentration of ultrafine particles emitted from vehicles. To investigate the availability of the TR-DMPS for monitoring transient roadside aerosols, the number size distribution of ultrafine particles was monitored at the Cheongnyangni roadside in Seoul on March 23, 2007 together with a Scanning Mobility Particle Sizer (SMPS). The roadside aerosols were monitored every 5 min and 0.1 sec by using the SMPS and the TR-DMPS, respectively. The concentration of ultrafine particles at the roadside was highly fluctuated for a short duration. From the comparison of particle number concentrations and size distributions between two instruments, it was confirmed that the SMPS provided fairly good time-averaged number size distribution although it did not follow rapid change of particle number concentration at the roadside. The TR-DMPS quickly responded to a rapid change of particle number concentration due to abrupt traffic flow. However, the TR-DMPS frequently showed electrical noise events, resulting in underestimated particle contamination. A more stable operation of the TR-DMPS is needed in application of roadside aerosol monitoring.

Chemical Compositions and Spatial Distribution Analysis of Fall-Out Particles in Suwon Area (수원지역 강하분진의 화학조성및 공간분포 분석)

  • 김현섭;이태정;김동술
    • Journal of Korean Society for Atmospheric Environment
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    • v.15 no.1
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    • pp.23-32
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    • 1999
  • Deposition is one of the important removal mechanisms for the ambient aerosol, and it also leads to adverse environmental and economic impacts. The purpose of this study was to investigate chemical compositions and spatial distributions of fall-out aerosols. A total number of 340 samples were collected at 35 sampling sites in Suwon area from January to November, 1996. Twelve inorganic elements (Al, Ba, Cd, Cr, K, Pb, Sb, Zn, Cu, Fe, Ni, and V) and eight ionic components ($F^-$, Cl, $NO_3^-$, $SO_4^{2-}$, $Na^+$, $NH_4^+$, $Mg^{2+}$, and $Ca^{2+}$) were analyzed by AAS and IC, respectively. The monthly variation showed that the flux of fall-out particles was increased in the spring season(March, April, and May) and decreased from August to October. Arithmetic mean flux of fall-out particles was 176.8 kg/$ extrm{km}^2$/day during the study period. The fluxes of each chemical species were $SO_4^{2-}$ 12.414, $Ca^{2+}$ 7.369, $NO_3^-$ 5.812, $Cl^-$ 3.566, $NH_4^+$ 3.176, Fe 3.107 kg/$\textrm{km}^2$/day, and so on. By using a kriging analysis, spatial distribution pattern of those fluxes was intensively studied. Total fluxes estimated in Suwon city were 8424.72t/y of fall-out particles, 519.27t/y of $SO_4^{2-}$, 336.79t/y of $Ca^{2+}$,267.34 t/y of $NO_3^+$, 155.36t/y of $Cl^-$, 147.79t/y of Fe.

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