초미세먼지의 토양기원 지시자로서 희토류 원소의 사용 가능성 평가

유근혜,박승식 한국대기환경학회 2014 한국대기환경학회 학술대회논문집 Vol.2014 No.10

선착장에서 실시간 광흡수 측정기를 이용한 초미세먼지의 광흡수 특성

유근혜,박승식,이권호 한국대기환경학회 2019 한국대기환경학회지 Vol.35 No.5

In this study, measurement of aerosol light absorption with 1-minute time resolution was made using a dualspot multi-wavelength aethalometer equipped with a PM2.5 impactor between October 23 and November 01, 2018 at a port of Gangneung. In addition, real-time measurements of PM10 and PM2.5 concentrations were carried out with a GRIMM light scattering monitor. Over the study period, PM10, PM2.5, black carbon (BC370) and aerosol light absorption coefficient (babs,370) at 370 nm wavelength peaked mostly in the morning (06:00~09:00) and evening hours (18:00~21:00), which are fairly coincident with activity hours of fishing boats at harbor. Furthermore, absorption Ångström exponent (AAE) values in the wavelength range of 370~520 nm (AAE370-520) and contribution of brown carbon (BrC) absorption at 370 nm (bBrC,370) to aerosol babs,370 were enhanced during the excursion. As the difference between BC370 and BC880 (BC at 880 nm) concentrations increases, the AAE370-520 values increased. During the excursion, maximum AAE370-520 and bBrC,370/babs,370 were in the range of 1.76~2.50 and 7.8~59.9%, respectively. These suggest the impact of light-absorbing organic aerosols to total aerosol light absorption at the site. Light absorption by BrC particles exhibited strong spectral dependence with increasing tendency in shorter visible wavelengths. Finally, enhanced BC370, babs,370, bBrC,370, AAE370-520, and BrC absorption contribution at 370 nm indicate the existence of light-absorbing organic aerosols in ship engine emissions at the seashore site in the absence of traffic, industrial sources, and biomass burning emissions.

차대 동력계를 이용한 차종별 배출량 분석

유근혜,송명기,오세호,최서영,전하정,배민석 한국대기환경학회 2022 한국대기환경학회 학술대회논문집 Vol.2022 No.10

대기오염집중측정소별 2013~2015년 사이의 PM2.5 화학적 특성 차이 및 유발인자 조사

유근혜,박승식,김영성,신혜정,임철수,반수진,유정아,강현정,서영교,강경식,조미라,정선아,이민희,황태경,강병철,김효선 한국대기환경학회 2018 한국대기환경학회지 Vol.34 No.1

In this study, difference in chemical composition of PM2.5 observed between the year 2013 and 2015 at six air quality intensive monitoring stations (Bangryenogdo (BR), Seoul (SL), Daejeon (DJ), Gwangju (GJ), Ulsan (US), and Jeju (JJ)) was investigated and the possible factors causing their difference were also discussed. PM2.5, organic and elemental carbon (OC and EC), and water-soluble ionic species concentrations were observed on a hourly basis in the six stations. The difference in chemical composition by regions was examined based on emissions of gaseous criteria pollutants (CO, SO2, and NO2), meteorological parameters (wind speed, temperature, and relative humidity), and origins and transport pathways of air masses. For the years 2013 and 2014, annual average PM2.5 was in the order of SL (≅ DJ)>GJ>BR>US>JJ, but the highest concentration in 2015 was found at DJ, following by GJ (≅SL)>BR>US>JJ. Similar patterns were found in SO4 2-, NO3 -, and NH4 +. Lower PM2.5 at SL than at DJ and GJ was resulted from low concentrations of secondary ionic species. Annual average concentrations of OC and EC by regions had no big difference among the years, but their patterns were distinct from the PM2.5, SO4 2-, NO3 -, and NH4 + concentrations by regions. 4-day air mass backward trajectory calculations indicated that in the event of daily average PM2.5 exceeding the monthly average values, >70% of the air masses reaching the all stations were coming from northeastern Chinese polluted regions, indicating the long-range transportation (LTP) was an important contributor to PM2.5 and its chemical composition at the stations. Lower concentrations of secondary ionic species and PM2.5 at SL in 2015 than those at DJ and GJ sites were due to the decrease in impact by LTP from polluted Chinese regions, rather than the difference in local emissions of criteria gas pollutants (SO2, NO2, and NH3) among the SL, DJ, and GJ sites. The difference in annual average SO4 2- by regions was resulted from combination of the difference in local SO2 emissions and chemical conversion of SO2 to SO4 2-, and LTP from China. However, the SO4 2- at the sites were more influenced by LTP than the formation by chemical transformation of locally emitted SO2. The NO3 - increase was closely associated with the increase in local emissions of nitrogen oxides at four urban sites except for the BR and JJ, as well as the LTP with a small contribution. Among the meterological parameters (wind speed, temperature, and relative humidity), the ambient temperature was most important factor to control the variation of PM2.5 and its major chemical components concentrations. In other words, as the average temperature increases, the PM2.5, OC, EC, and NO3 - concentrations showed a decreasing tendency, especially with a prominent feature in NO3 -. Results from a case study that examined the PM2.5 and its major chemical data observed between February 19 and March 2, 2014 at the all stations suggest that ambient SO4 2- and NO3 - concentrations are not necessarily proportional to the concentrations of their precursor emissions because the rates at which they form and their gas/ particle partitioning may be controlled by factors (e.g., long range transportation) other than the concentration of the precursor gases.

2014년 2월 광주 도심에서 발생한 PM2.5 고농도 사례 연구

유근혜,이복진,박승식,정선아,조미라,임용재,김순태 한국대기환경학회 2019 한국대기환경학회지 Vol.35 No.2

Severe hazes, which are generally characterized by high concentration level of fine particulate matter (PM2.5) and visibility impairment, occurring during winter have still been a great challenge in Korea. The control strategies for air pollution in Korea were not only cutting-edge issues of PM2.5 study, but an imperative problem to be addressed to the government and the public. A severe haze event lasting approximatively 10 days occurred in February 2014 in Gwangju, Korea. Hourly measurements of PM2.5 and its chemical constituents such as organic and elemental carbon (OC and EC), ionic species, and metal species were made at the air pollution intensive monitering station in Gwangju. Over the haze event, concentrations of three secondary ionic species (=SO4 2-+NO3 -+NH4 +) and organic matter (=OC×1.6) were on average 50.3 and 18.2% of PM2.5, respectively. Hourly highest concentration among the major chemical species was SO4 2- with the concentration of 42.7 μg/m3 and contribution of 42.9% to the PM2.5. Organic aerosols were strongly associated with local traffic emissions, with some contribution from biomass burning activities at a rural site at northern and/or northeastern directions from the site. Another important feature found during high PM2.5 event was that SO2 and NO2 concentrations were approximately 2~4 times lower in Gwangju than those in Seoul, Daejeon, and Ulsan. However, secondary ionic species concentrations in Gwangju were significantly higher than, or similar to those in other three metropolitan areas. This could possibly be attributed to high O3 concentration (53~71 ppb) in the afternoon, enhancing the formation of SO4 2- and NO3 - through photochemical reactions of SO2 and NO2, and finally leading to PM2.5 increase. Over the high PM2.5 event, SO4 2- and NO3 - concentrations showed similar temporal trends, but their pollution characteristic was completely different. For example, an increasing rate in NO3 - concentration was greatly influenced by both local secondary production and long-range transportation (LTP). Whereas, it was found that impact by LTP was likely an important factor to control the increase in SO4 2- concentration. In conclusion, it is suggested that cutting nitrogen oxides from vehicle emissions is a very important step to control winter haze event in Gwangju more effectively on local scale.

광주 지역에서 2018년 1월 측정한 초미세먼지의 오염 특성

유근혜,박승식,정선아,조미라,장유운,임용재,김영성,Yu, Geun-Hye,Park, Seung-Shik,Jung, Sun A,Jo, Mi Ra,Jang, Yu Woon,Lim, Yong Jae,Ghim, Young Sung 한국입자에어로졸학회 2019 Particle and Aerosol Research Vol.15 No.3

In this study, hourly measurements of $PM_{2.5}$ and its major chemical constituents such as organic and elemental carbon (OC and EC), and ionic species were made between January 15 and February 10, 2018 at the air pollution intensive monitering station in Gwangju. In addition, 24-hr integrated $PM_{2.5}$ samples were collected at the same site and analyzed for OC, EC, water-soluble OC (WSOC), humic-like substance (HULIS), and ionic species. Over the whole study period, the organic aerosols (=$1.6{\times}OC$) and $NO_3{^-}$ concentrations contributed 26.6% and 21.0% to $PM_{2.5}$, respectively. OC and EC concentrations were mainly attributed to traffic emissions with some contribution from biomass burning emissions. Moreover, strong correlations of OC with WSOC, HULIS, and $NO_3{^-}$ suggest that some of the organic aerosols were likely formed through atmospheric oxidation processes of hydrocarbon compounds from traffic emissions. For the period between January 18 and 22 when $PM_{2.5}$ pollution episode occurred, concentrations of three secondary ionic species ($=SO{_4}^{2-}+NO_3{^-}+NH_4{^+}$) and organic matter contributed on average 50.8 and 20.1% of $PM_{2.5}$, respectively, with the highest contribution from $NO_3{^-}$. Synoptic charts, air mass backward trajectories, and local meteorological conditions supported that high $PM_{2.5}$ pollution was resulted from long-range transport of haze particles lingering over northeastern China, accumulation of local emissions, and local production of secondary aerosols. During the $PM_{2.5}$ pollution episode, enhanced $SO{_4}^{2-}$ was more due to the long-range transport of aerosol particles from China rather than local secondary production from $SO_2$. Increasing rate in $NO_3{^-}$ was substantially greater than $NO_2$ and $SO{_4}^{2-}$ increasing rates, suggesting that the increased concentration of $NO_3{^-}$ during the pollution episode was attributed to enhanced formation of local $NO_3{^-}$ through heterogenous reactions of $NO_2$, rather than impact by long-range transportation from China.

광주 지역에서 생성되는 2차 무기염 성분의 생성기작 규명

유근혜,주서령,박승식 한국대기환경학회 2021 한국대기환경학회 학술대회논문집 Vol.2021 No.10

광주지역에서 PM2.5의 주요 구성성분으로 알려진 2차 무기염(황산염, 질산염, 암모늄염) 입자의 생성과정을 규명하고자 여름철과 겨울철에 집중측정을 수행하였다. 본 연구는 측정 기간 동안 PM2.5 고농도 사례 발생 시 황산염 입자 생성 사례와 질산염 입자 생성 사례를 분석하였다. 황산염은 여름철 낮시간에 국지적 또는 측정 지점 인근에 위치한 산업단지로부터 유입된 SO₂가 산화제와 강한 광화학 산화 과정으로 생성되어 고농도 현상이 나타났다. 질산염 입자의 생성 과정은 4종류의 사례(사례1: 6월 5~8일, 사례2: 12월 7일, 사례3: 12월 11일, 사례4: 12월 22~23일)에 대해 분석하였다. ① 사례1은 바이오매스 연소와 광화학 산화과정이 결합하여 나타났다. 또한, 한반도 주변에 형성된 고기압과 낮은 풍속 및 낮은 대기경계층과 같은 대기 정체 현상으로 국지적으로 발생한 대기오염물질이 축적 및 2차 오염물질을 생성하여 PM2.5 증가 현상이 발생하였다. 또한 질량크기분포 분석 결과 NO₃<SUP>-</SUP>, SO₄<SUP>2-</SUP>, NH₄<SUP>+</SUP> 및 K<SUP>+</SUP> 모두 응결모드(~0.3 ㎛)에서 피크를 보여 이들 2차 무기염 성분들은 여름철 높은 기온으로 대기 중 기체상전구물질과 OH 라디칼과의 산화반응을 통해 생성된 것으로 판단된다. ② 사례2~4는 바람이 거의 불지 않고, 높은 상대습도의 안정된 기상 조건에서 NO₂의 액상 산화 과정을 통해 질산염 생성을 촉진하였다. 또한 기체상 전구물질 NH₃의 높은 농도는 대기 중 암모늄 형성을 활발하게 하여 PM2.5 농도 증가에 영향을 주었다. 또한 NO₃<SUP>-</SUP>, SO₄<SUP>2-</SUP> 및 NH₄<SUP>+</SUP>의 질량 크기 분포는 약 1.0 ㎛에서 액적모드의 크기 분포를 보여줌으로써 기체상 전구물질들의 액상 반응이 2차 무기염 성분의 생성과정으로 판단된다.

겨울철 레보글루코산 및 갈색탄소 흡수계수 특성

유근혜,송명기,오세호,최서영,전하정,고동훈,정혜지,배민석 한국대기환경학회 2023 한국대기환경학회 학술대회논문집 Vol.2023 No.10

대기정체조건하에서 관측된 수용성 에어로졸 입자의 크기분포 변화

유근혜,김준기,박승식 한국대기환경학회 2018 한국대기환경학회 학술대회논문집 Vol.2018 No.10

2015 초등학교 3-4학년 음악교과서에 적용된 음악적 창의・융합 사고 역량 분석

유근혜,권수미 한국음악학학회 2020 음악학 Vol.28 No.1

The purpose of this study is to analyze how the 'musical creativity convergence thinking competence' among the six core competencies required in the 2015 revised music and curriculum was designed to be reflected and instructed in the 3rd and 4th grade music textbooks, and the basis of textbook production. It is to improve the elements and scope of application for creative activities based on the music curriculum. To this end, we analyzed 149 textbook songs to which musical creativity convergence thinking competence were applied among 9 types of textbooks, totaling 18 books in elementary music 3rd and 4th grade. In the music and curriculum contents and achievement standards, areas, music elements, achievement standards, functions, and related subjects were reorganized into detailed analysis types to analyze the frequency of application of musical creativity convergence thinking competence and the types of learning activities. As a result of research, it is necessary to apply more musical creativity convergence thinking competence in the creative area, and the diversity of concepts and standards of creative and convergence activities in relation to changing the song or make a wordingwith the highest frequency in achievement standards and functions. In addition, the need for more diverse creative and convergence activities has been revealed, as it is focused on linkage learning with Korean language or applied to music subjects with high frequency without linkage with other subjects. 본 연구는 2015 개정 음악과 교육과정에서 요구하는 6가지 핵심역량 중 ‘음악적 창의・융합 사고 역량’이 초등학교 3-4학년 음악교과서에 어떻게 반영되고 지도하도록 구성되었는지 분석함으로써, 교과서 제작의 근거가 되는 음악교육과정을 바탕으로 창작 활동에 대한 적용 요소와 범위에 대하여 재고하는 것을 연구목적으로 한다. 이를 위하여 초등 음악 3-4학년 교과서 9종, 총 18권중 음악적 창의・융합 사고 역량이 적용된 제재곡 149곡을 대상으로 분석하였으며, 음악과 교육과정 내용 체계 및 성취기준에서 영역, 음악 요소, 성취기준, 기능, 연계 교과를 세부 분석 유형으로 재구성하여 음악적 창의・융합 사고 역량의 적용 빈도와 학습 활동 유형을 분석하였다. 연구결과, 창작 영역에서 더많은 음악적 창의・융합 사고 역량의 적용이 필요하며, 성취기준과 기능에서가장 높은 빈도를 보인 노랫말을 바꾸거나 말붙임새로 만들기와 관련하여 창의・융합 활동의 개념과 기준의 다양성에 대한 재고가 필요하였다. 또한 국어와의 연계 학습에 집중되거나, 다른 교과와의 연계 없이 음악 교과에만 해당 역량이 높은 빈도로 적용된 점에서 좀 더 다양한 창의・융합 활동의 필요성이 드러났다.