검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 338

        261.
        1991.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        With a modern microdensitometer and POSS glass copies, we have performed an automated star counting in two colors, blue and red, over the region containing Bok globule B361. Distribution of the measured extinction values over the projected angular distance from the cloud center was approximated by a power-law, and the resulting power-law indices for the blue and red are shown to be distinctly different from each other. The difference in the power-law index indicates that the mean dust size increases towards the cloud center. Possible physical causes for such size variation are briefly discussed.
        4,000원
        263.
        1987.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        By inverting the brightness integral for the dust-scattered continuum, we have determined how the dust grains are distributed inside the Orion nebula. The scattering characteristics of the Orion dust at a given wavelength is kept constant within the nebula, and the geometry of the nebula is assumed to have a hemispherical shape. The resulting radial distance dependence of the distribution of dust number density, N d ( r ) , shows that the dust grains are depleted at the central region of the Orion nebula and concentrated in the region 5 ′ ∼ 6 ′ away from the Trapezium stars. The scattering characteristics of the Orion dust are of moderately forward throwing nature, and the Orion dust has low values of albedo.
        6,400원
        267.
        1971.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        증량제의 특성 중 Sumithion 분제의 주성분 분해에 영향을 미치는 요인을 밝힐 목적으로 시험하여 다음과 같은 결과를 얻었다. 가. 증량제의 특성 중 수분함량, 흡습성, C.E.C. 활성천, 염기총량, 표면적 등이 Sumithion 분제의 주성분 분해에 영향을 미치는 요인이 됨을 알았고, 나. 증량제에 의한 Sumithion의 분해산물은 Dimethyl phosphorothionate와 3-methyl-4-nirophenol 및 이의 유연화함은, n-hexane, ethyl ether 불용, methyl alcohol, ethyl, alcohol가용의 화함물이 있음을 알았다. 다. 증량제의 종류별로는 벤토나이트, 규조로, 카올린, 활석의 순으로 분해율이 높았다. 라. 그리고 증랑제의 Sumithion 분제 주성분 변화에 영향을 미치는 특성 중 수분과 염기가 가장 대표적인 주성분 분해 요인으로 보인다.
        4,000원
        268.
        2022.12 KCI 등재 서비스 종료(열람 제한)
        황사 구성 광물의 지질학적 근원을 추적하기 위해, 발원지인 몽골 남부 고비사막 기반암의 광물학적 특성을 분석하였다. 황사 발원지 기반암은 고생대 화산암 및 화산쇄설성 퇴적암, 고생대 화강암류, 중생대 퇴 적암으로 구성되어 있다. 고생대 화산암 및 퇴적암은 매우 치밀하게 고화 및 변형되어 산지를 형성하며, 중 생대 백악기 퇴적암은 고생대 화산암 및 퇴적암으로 이루어진 산맥 사이의 분지를 충전한다. 고생대층 암석은 녹니석과 사장석 함량이 높고, 녹색편암상의 변성작용을 받았다. 중생대 퇴적암층은 녹니석이 드물고, 스멕타 이트, 일라이트-스멕타이트 혼합층, 카올리나이트 등의 점토광물이 풍부하다. 고생대 화강암류에는 각섬석과 흑운모가 특징적으로 함유되어 있다. 발원지 기반암의 광물학적 특성과 비교하면, 황사는 고생대층과 중생대 층 기원 쇄설물의 혼합물이나, 중생대 퇴적암에 더 가깝다. 점토 함량이 높고, 덜 고화된 중생대 퇴적암류는 잘 부스러져 침식되기 쉬운 실트질 표토가 되어 황사 광물 구성에 기여한다.
        269.
        2022.06 KCI 등재 서비스 종료(열람 제한)
        Baengnyeongdo, located within the Asian dust stream, is an ideal place to analyze Asian dust moving into the West Sea due to its low emission of artificial pollutants. Baengnyeongdo is being used to analyze the vertical distribution of dust from the lower atmosphere to the upper layer through remote observation. This study compared the ground concentration of dust between Baengnyeongdo and the metropolitan area, estimated the lag time of transport of Asian dust from Baengnyeongdo to the metropolitan area, and examined the homogeneity of upper winds using the rawinsonde method. The results showed that the cross correlation coefficient was higher and the lag time was shorter for each observation station when the distance from Baengnyeongdo was shorter. The upper wind at Baengnyeongdo is dominated by the west/northwest wind. It is the basis for the correlation of dust concentration between Baengnyeongdo and the metropolitan area located to the east. In the future, upper wind data and Asian dust concentration data over the West Sea and Baengnyeongdo are expected to contribute to research related to the movement and prediction of Asian dust and preparation for Asian dust in the metropolitan area.
        270.
        2022.06 KCI 등재 서비스 종료(열람 제한)
        This study investigated characteristics of meteorological parameters and ionic components of PM2.5 during Asian dust events on November 28 and 30, 2018 at Busan, Korea. The seasonal occurrence frequencies of Asian dust during 1960∼2019 (60 years) were 81.7% in spring, 12.2% in winter, and 6.1% in autumn. Recently, autumn Asian dust occurrence in Busan has shown an increasing trend. The result of AWS (automatic weather station), surface weather chart, and backward trajectory analyses showed that the first Asian dust of Nov. 28, 2018, in Busan came with rapid speed through inner China and Bohai Bay from Mongolia. The second Asian dust of Nov. 30, 2018, in Busan seems to have resulted from advection and deposition of proximal residual materials. These results indicated that understanding the characteristics of meteorological parameters and ionic components of PM2.5 during Asian dust events could provide insights into establishing a control strategy for urban air quality.
        271.
        2022.05 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to propose a way to increase the accuracy and precision of β-ray measurement equipment. Statistical processing results of equivalent evaluation data from 2016 to 2021 confirmed that the concentration of micro dust measured by β-ray measurement equipment was higher than that of micro dust sampler. According to quarterly data, it was confirmed that the data from the third quarter (July to September) showed a different trend from other periods, which is assumed to be due to weather conditions. This study indicates that automatic micro-dust measurement equipment evaluation at air pollution measuring stations during the third quarter should be excluded. The evaluation cycle should be changed from once every two years to quarterly. In addition, when the criterion for determining equivalence evaluation falls within the range of the slope and intercept values of the existing trend line, it is necessary to evaluate the R2 value together and reduce the slope from 0.9-1.1 to 0.9-1.0.
        272.
        2021.12 KCI 등재 서비스 종료(열람 제한)
        한반도는 황사의 이동 경로에 있으나, 풍화와 침식이 활발한 산악 지형에서 황사의 퇴적을 확인하기는 어렵다. 이 연구에서는 설악산 알칼리장석화강암 토양의 세립실트(< 20 μm)에 점토광물 특성, 광물조성, 미세 조직 분석을 실시하여 산악지역 토양 내 황사퇴적물의 존재 상태를 조사하였다. 이 지역 토양 세립실트는 기 반암 유래 쇄설성 입자, 황사퇴적물, 그리고 이들의 풍화물로 구성되어 있다. 토양 내 황사기원 광물로 2:1 층상규산염, 녹니석, 각섬석, 녹염석, 함칼슘사장석이 확인되었다. 기반암인 알칼리장석화강암은 석영과 알칼 리장석으로 구성되며, 알칼리장석 중 앨바이트가 부분적으로 풍화되어 소량의 깁사이트와 고령토 광물이 생 성되었다. 산성토양환경에서 일라이트-스멕타이트 계열 2:1 층상규산염의 팽윤성 층간에 다핵 Al 양이온 종들 이 교환 및 고정되어 히드록시-Al삽입점토광물이 생성되었다. 2:1 층상규산염 총량을 기준으로 평가하면 조사 한 토양 세립실트 내 황사의 양은 70% 정도로 추정된다.
        273.
        2021.09 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to elucidate the spatio-temporal characteristics of ultrafine dust generation in East Asia and the synoptic climate patterns related to its dispersal which has its adverse effects on public health across East Asia. To achieve this purpose, Level 3 monthly Aerosol Optical Depth (AOD) data extracted from MODIS satellite imagery (MOD08_M3) representing particle matters less than 2.5 micrometer (PM2.5) and the NCEP-NCAR reanalysis I upper-level climatic data associated with the exacerbation of ultrafine dust problem are analyzed for the recent 20-year (2001-2020) period. Analyses of long-term average MOD08 data show that high AOD value exceeding 0.5 or more frequently occurred in populous cities in East Asia but mainly in the vicinity of densely populated large rivers and the eastern lowlands in China between mid-winter and mid-spring, which is attributable to the accumulation effects of continuous fossil fuel consumption for heating and manufacturing. Despite the overall decreasing trend of ultrafine dust across China in the 2010s, the weakened westerlies in the warmer climate as well as its continuous generation from the densely populated industrial regions of China provide a favorable synoptic climate condition for frequent severe ultrafine dust problems across East Asia including South Korea. These results indicate that ultrafine dust from China is a long-lasting transboundary environmental problem across East Asia, which needs long-term international cooperation in developing the sustainable policies.
        274.
        2021.03 KCI 등재 서비스 종료(열람 제한)
        In this study, the composition and morphology of deposited dust particles with size ranging from a few to tens ㎛ were investigated using SEM/EDX (scanning electron microscopy with energy dispersive x-ray spectrometer). Then deposited dust particles were classified into 8 groups: quartz, aluminosilicates, ca-rich, Fe/Ti oxide, carbon-rich, industrial particle, Fe-rich, and biogenic particle. The sources of deposited dust were high in the order of aluminosilicates 41% > biogenic 18% > Fe-rich 11% > quartz and C-rich 8% > industrial 7% > Fe/Ti oxide 5% > Ca-rich 1%. In particular, the ratio of biogenic particles was relatively high due to influence of pollen. The ratio of carbon-rich was 11% at YM site, 10% at MD site, and 4% at MO site, and the site close to the large emission source was high.
        275.
        2020.05 KCI 등재 서비스 종료(열람 제한)
        Fine dust is one of the most critical environmental issues in Korea, and the government recognizes the need to establish customized reduction policies based on regional characteristics. Several studies on air pollutants investigate whether factories affect the distribution of fine dust in a particular region. However, understanding the impact of the entire industry sector requires further investigation. This study identifies the impacts of industrial characteristics on fine dust levels of 141 municipalities across Korea in 2016. A total of 23 variables were used, of which 12 referred to industries and 11 to general characteristics of each city. Due to the high correlation between independent variables, partial least squares (PLS) regression models were used. The analysis identified 14 significant variables for PM10 and 13 for PM2.5. Therefore, the results suggest that local industrial characteristics can significantly influence fine dust levels and provide suggestions for establishing customized reduction policies based on local characteristics.
        276.
        2020.01 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to investigate the relationship of fine dust PM10 and heavy metals in PM10 in Asian dust flowing into Gwangju from 2013 to 2018. The migration pathways of Asian dust was analyzed by backward trajectory analysis using HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) model, and the change of heavy metal concentration and heavy metal content per 1 μg/m3 of fine dust PM10 in Gwangju area were analyzed. Also, the characteristics of the heavy metals were analyzed using the correlation between the heavy metals in PM10. As a result of analyzing Asian dust entering the Gwangju region for 6 years, the average concentration of PM10 measured in Asian dust was 148 μg/m3, which was about 4.5 times higher than in non-Asian dust, 33 μg/m3. A total of 13 Asian dust flowed into the Gwangju during 6 years, and high concentration of PM10 and heavy metals in that were analyzed in the C path flowing through the Gobi/Loess Plateau-Korean Peninsula. As a result of the correlation analysis, in case of Asian dust, there was a high correlation between soil components in heavy metals, so Asian dust seems to have a large external inflow. On the other hand, in case of non-Asian dust, the correlation between find dust PM10 and artificial heavy metal components was high, indicating that the influence of industrial activities in Gwangju area was high.
        277.
        2019.10 서비스 종료(열람 제한)
        최근 정부의 미세먼지 특별법이 발효됨에 따라 비상저감조치 시행시 건설현장 및 공장 작업시간을 조정 및 단축하도록 권고하고 있지만 정량적인 기준 및 저감기술 부재로 인해 기업의 자발적 참여를 유도하는 수밖에 없는 실정이다. 또한 최근 도로포장 재료생산 플랜트에서 발생하는 비산먼지 및 유해가스로 인한 피해사례가 다수 발생하고 있으며 이로 인한 공장 주변 주민들과의 갈등이 심각한 실정이다. 이에 본 연구에서는 국내외 도로포장 관련 비산먼지 발생현황 및 관련법에 대한 조사를 수행하고, 도로포장 전주기(생산-시공-운영)에서의 단계별 발생량 조사를 통해 각 단계에 적합한 비산먼지 저감기술 개발 및 적용방안을 제시하고자 한다.
        278.
        2019.10 서비스 종료(열람 제한)
        현재 (초)미세먼지의 주요 발생 원인이 되고 있는 질소화합물(NOx) 및 PM10, PM2.5 미세먼지 입자 제거를 위해 화물차를 비롯한 경유차에 대한 다양한 규제와 정책이 추진되고 있으나 가시적인 개선 효과가 나타나지 않아 근본적인 대책이 필요한 실정이다. 이에 관한 대책으로서 국내에서는 도로 물청소, 분진흡입, 노후 경유차 대도시 운행 제한 등을 시행하고 있으나 구체적인 저감효과에는 한계가 있어 능동적인 대응 방안을 마련이 시급한 실정이다. 또한, 도심부 도로에서 발생하는 미세먼지는 도로변을 걷는 보행자와 차량 운전자의 건강에 직접적인 영향을 주는 심각한 환경문제로 대두됨에 따라 도로변 미세먼지 저감 필요성이 증대되고 있다. 따라서, 이 연구에서는 기능성 건설재료를 활용하여 도로변 미세먼지 저감 기술 개발에 관한 실증 방안을 제시하고자 한다.
        279.
        2019.04 서비스 종료(열람 제한)
        In this study, the mechanical properties of concrete incorporating blast furnace slag with 60 % were analyzed according to CBS-Dust replacement rate. Results indicate that replacement of more than 10 % of CBS-Dust have a positive effect on reducing waste disposal costs and strength improvement
        280.
        2019.03 KCI 등재 서비스 종료(열람 제한)
        We explored the transporting processes for the Asian dust observed over South Korea. The frequency of Asian dust days (ADDs) were used to analyze the associations of the ADDs with land surface conditions over the four source regions, including inner-Mongolia, the Gobi Desert, Manchuria, and Loess Plateau, and atmospheric synoptic variables over central and eastern Asia. Precipitation and Palmer Drought Severity Index (PDSI) in the source regions during the previous summer were negatively correlated with the ADDs in South Korea. Statistically and physically more significant processes were found in the associations of atmospheric synoptic conditions with the ADDs. The intensified winds of northwesterly-northerlynorthwesterly over a pathway of the Asian dust from the source regions to South Korea were identified during high ADDs years in South Korea. A dipole pattern of anti-cyclonic and cyclonic anomalies over central and eastern Asia, respectively, supported the Asian dust pathway.