• Title/Summary/Keyword: yellow sands

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Isentropic Analysis for the Long Range Trajectories of Yellow Sands (등엔트로피 궤적에 의한 황사의 장거리 이동 경로 분석)

  • 윤순창;박경선
    • Journal of Korean Society for Atmospheric Environment
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    • v.7 no.2
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    • pp.89-95
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    • 1991
  • Yellow sands often occur in Korea during April and May each year, and they are believed to come from the Mongolian Gobi desert as the snow starts to melt in Spring time. Since the analysis of aerosol particulates can hardly distinguish the origin of particulates, the isentropic analysis of meteorological data is often used for the trajectories of the long range transport of yellows sand or air pollutants. The yellow sand case of April 9 $\sim$ 15, 1988, in Korea is analyzed for the identification of long range transport of yellow sands and their trajectories in East Asia, using isentropic analyses. We have tranformed the ECMWF grid data, analyzed in pressure coordinates, into the isentropic coordinates and then have traced the 286 K and 290 K air mass which started Gobi desert. The result shows the transport of yellow sands from the Gobi desert to the Korean peninsula.

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Individual Particle Analysis for Developing a Source Profile of Yellow Sands (황사의 오염원분류포 개발을 위한 개별입자분석)

  • 강승우;김동술
    • Journal of Korean Society for Atmospheric Environment
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    • v.16 no.6
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    • pp.565-572
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    • 2000
  • To quantitatively estimate mass contribution of long-range transported yellow sand, their sources should be separated independently from various local soil sources having similar elemental compositions. While it is difficult to estimate total mass loadings of pure yellow sand by traditional bulk analysis, it can be clearly solved by an particle-by-particle analysis. To perform this study, two yellow sand samples and three local soil samples were collected by a mini-volume sampler. These samples were three analyzed using a scanning electron microscope(SEM) equipped with an energy dispersive x-ray analyser (EDX) was used to obtain basic chemical information of individual yellow san particles. A total of 19 elements in a single particle were measured to develop a source profile with newly created homogeneous particle classes (HPCs) as chemical variables. The present study showed that the yellow sand samples as well as three local soil samples were characterized with reasonably well created HPCs. Finally the mass fraction of each HPC in each sample was calculated and then compared each other.

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Grain-Size Distribution of Source Areas of Asian Dust (Yellow Sand) in China

  • Yi, Hi-Il;Shin, Im-Chul
    • The Korean Journal of Quaternary Research
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    • v.21 no.2
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    • pp.77-79
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    • 2007
  • The source regions of Asian Dusts (Yellow Sands) in the western part of China are investigated, and the soil samples are collected samples for approximately 15 days during the spring of 2005. Particle sizes of sediments are analyzed and compared with each other. These grain-size analyses from the source areas can be compared Particle sizes between loess deposits and desert sands in western part of China and desert areas show distinctive differences. Loess deposits are predominantly composed of fine sands and silts. The distinction between the final characteristics of Asian Dust particles arrived in Korea and characteristics during transportation can be recognized comparison with the Asian Dust particles collected where the dust particles settled down. The characteristics of Asian Dust particle sizes can provide the basic information regarding the transportation history from the source region.

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The Development of Face Cover Designs to Activate Outdoor Life (아웃도어 라이프 활성화를 위안 페이스 커버 개발 연구)

  • Kim, Chan-Ju;Ro, Mi-Kyung
    • Journal of the Korean Society of Costume
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    • v.59 no.1
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    • pp.47-59
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    • 2009
  • This paper aimed at the development of face covers which is face protection articles for blocking UV rays and yellow sands, with a view to assist the further activation of outdoor life. The four-stage design process of field study, design, design evaluation, final selection of designs was set up for the effective product development. Field study included on-line and off-line market survey on the products for sale in market and observation on those wearing face covers. Depth interviews were done to know consumer understandings and satisfaction levels for current face covers. The results of market survey showed that most of the face covers currently in the market were mask types, which were produced for the blocking of dust and yellow sands rather than UV ray protection. The major clients of the mask were the women in their 30's-50's and the designs for these clients were very limited. Since the number of younger women and men enjoy the outdoor sports has increased, the face covers for these people should be developed. For this purpose, the direction of new face cover design had 2 points: diversification of design in terms of color, material, shape and giving seasonal differences. 12 designs were designed on the first design stage, but after both wearing test by 16 testees and UV ray blocking test to evaluate these designs, 6 face cover designs were finally selected.

The Records of Origin and Transport of Sediments From the Past to the Present in the Yellow Sea

  • Yi, Hi-Il;Chun, Jong-Hwa;Shin, Im-C.;Shin, Dong-Hyeok;Jou, Hyeong-Tae
    • Journal of the korean society of oceanography
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    • v.39 no.1
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    • pp.96-106
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    • 2004
  • A total of 116 surface sediment samples were obtained on the Yellow Sea and analyzed for grain size and geochemical elements in order to interpret the present sediment transportation. Thirty-nine cores and 3,070 line-km shallow seismic profiles are analyzed for sedimentary records of Yellow Sea in the past. Results show that the boundary of sediment transport between Korean side and Chinese side is about between $123^{\circ}E$ and $124^{\circ}E$. The similar result is produced from Shi et al. (in this publication). Two cyclonic patterns of surface sediments are recognized in the northeastern and southwestern Yellow Sea, while the strong front zone of the mud patch and sandy sediments are found in the southeastern Yellow Sea (the southwestern part of Korean coasts). The formation of fine-particle sediment packages, called for Northwest Mudbelt Deposit (NWMD), Hucksan Mudbelt Deposit (HSMD) and Jeju Mudbelt Deposit (JJMD), are resulted from eddies (gyres) of water circulations in the Yellow Sea. NWMD has been formed by cyclonic (anticlockwise) eddy. NWMD is composed of thick, homogeneous, relatively semi-consolidated gray clay-dominated deposit. On the other hand, HSMD and JJMD are formed by anticyclonic (clockwise) eddies. They are thick, homogeneous, organic-rich gray, silt-dominated deposit. Both core and surface sediments show that the middle zone across Chinese and Korean side contains bimodal frequency of grain-size distribution, indicating that two different transport mechanisms exist. These mud packages are surrounded by sand deposits from both Korea and China seas, indicating that Yellow Sea, which is the shallow sea and epicontinental shelf, is formed mostly by sand deposits including relict sands. The seismic profiles show such as small erosional/non-depositional channels, sand-ridges and sand-waves, Pleistocene-channelfilled deposits, a series of channels in the N-S major channel system, and thick Holocene sediment package, indicating that more complex sedimentary history exists in the Yellow Sea.

Basic Research on the Quantitative Estimation of Yellow Sand (黃砂의 量的推定을 위한 基礎硏究)

  • 김동술
    • Journal of Korean Society for Atmospheric Environment
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    • v.6 no.1
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    • pp.11-21
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    • 1990
  • To quantitatively estimate the effect of yellow sand(loess) fromt he Northern China, various soil sources having similar chemical compositions to yellow sands should be separated and identified. After that, mass contribution for yellow sand can be calculated. The study showed that it was impossible to solve this problem by the traditional bulk analyses. However, particle-by-particle analysis by a CCSEM (computer controlled scanning electron microscope) gave enormous potentials to solve it. To perform this study, seven soil source data analyzed by CCSEM were obtained from Texas, U.S.A. Initially, each soil date was classified into two groups, coarse and fine particle groups since the particle number distribution showed a minimum occurring at 5.2$\mu$m of aerodynamic diameter. Particles in each group were then classified into one of the 283 homogeneous particle classes by the universal classification rule which had been built by an expert system in the early study. Further, mass fractions and their uncertainties for each class in each source were calculated by the Jackknife method, and then source profile matrix for the 7 soil sources was created. To use the profile matrix in the study of source contribution, it is necessary to test the degree of collinearity among sources. The profiles were tested by the singular value decomposition method. As a result, each soil source characterized by artificially created variables was totally independent each other and is ready to use in source contribution studies as a receptor model.

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Leaching Characteristic Analysis of Cement Solidified Radioactive Waste Attached by Yellow Sand Rain (황사빗물의 영향에 의한 방사성 폐기물 시멘트 고화체의 침출특성 분석)

  • 김혜진;이수홍;황주호;이재민
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2003.11a
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    • pp.244-250
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    • 2003
  • With a recent public concern rising on the radioactive waste, it is disclosed that the problem is more serious than expected. This research has been conducted to find effects of yellow sandy rainwaters on the solidified cement of mid-and-low level radioactive waste. The ANS 16.1 standard test method was chosen for this leaching experiment. Make a cement solidified radioactive waste that contains Co nuclide, and fabricate it for over 28 days. Then, decide on the volume of leaching water and the concentration of ion and metal in leachate from the mass concentration of yellow sands in atmosphere. In this paper, we have taken a short look at characteristics of yellow sand. Before going into the leaching experiment, we decided experimental conditions first. Then, it was evaluated and analyzed how sandy rainfalls have impact on the cement solidified radioactive waste based on data from 90 days of leaching experiment.

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Individual Particle Analysis of Yellow Sands by SEM/EDX (SEM/EDX를 이용한 황사의 입자별 분석)

  • 강승우;김동술
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 1999.10a
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    • pp.309-310
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    • 1999
  • Loess (黃土)는 지구의 10 %를 차지하고 있으며, 황사 (黃砂)폭풍으로 장거리이동이 가능하여 동아시아까지 이동할 수 있다 (Zhang De'er, 1982). 황사현상은 최근 동북아시아에서 급속한 산업발달과 인구증가, 그리고 생활수준의 향상에 따라 많은 양의 오염물질이 대기로 방출되고 있다. 특히 중국이 이 지역에서 배출되는 대기오염물질의 대부분을 배출하고 있다 (국립환경 연구원, 1998).(중략)

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