• Title/Summary/Keyword: 동화지구

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Characteristics of Geochemical Processes along the Salinity Gradient in the Han River Estuary (한강 기수역에서 염분구배에 따른 지화학적 특성 변화)

  • 김동화;박용철;이효진;손주원
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.9 no.4
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    • pp.196-203
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    • 2004
  • To understand the geochemical processes in the Han River Estuary, distributions and behaviors of nutrients, dissolved organic matters, and uranium were investigated and analyzed during estuarine tidal mixing in June 2000 and February 2001. The distribution of inorganic nutrients showed very dynamic distributional patterns implying an apparent nitrification process and a concave non-conservative mixing along the salinity gradient. Dissolved organic carbon was high in the upstream region and decreased sharply in the low salinity region of around 5 psu. The 3-D fluorescence characteristic of dissolved organic matter showed two distinct fluorophores in the study area. Biomacromolecules originated mainly from the indigenous biochemical processes and geomacromolecules from terrestrial humic materials. In the study area, the distribution of geomacromolecule showed a concave non-conservative property along the salinity gradient presumably due to the flocculation and removal processes in the estuary. Meanwhile, distribution of the dissolved uranium, mainly in the form of stable uranium carbonate complex, also showed a concave non-conservative property along the salinity gradient in the Han River Estuary. From this study, the removal rate of dissolved uranium in the Han River Estuary was estimated to be about 7.1 ton per year.

Petrology of the Volcanic Rocks in Geoje Island, South Korea (거제도 화산암의 암석학적 연구)

  • 윤성효;이준동;이상원;고정선;서윤지
    • The Journal of the Petrological Society of Korea
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    • v.6 no.1
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    • pp.1-18
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    • 1997
  • Andesitic pyroclastics and lava flows are deposited as a part of composite volcanoes by Cretaceous volcanic activity in Geojae Island, off the coast of Korea. The andesitic pyroclastics are composed of tuff breccia and lapilli tuff minor intercalated tuff. Lava flows are divided into dense and porphyritic andesite containing phenocrysts of plagioclase, pyroxene, and/or hornblende. The andesitic rocks represent charactersitcs of carc-alkaline BAR association with basalt, basaltic andesite, andesite, and dacite to rhyolite. Major element variations of the volcanic rocks show that $Al_2O_3$, total FeO, CaO, MgO and $TiO_2$ decrease with increasing $SiO_2$ but $K_2O$ and total alkalis increase, and represent differntiation trend of calc-alkaline rock series. In spider diagram, contents of Sr, K, Rb, Ba, and Th are relatively high, but contents of Nb, P, Ti and Cr are low. These petrochemcial characteristics are similar to those of rocks from island arc or continental margein related to plate subduction. Chondrite-normalized REE patterns of volcanic rocks are paralle to subparallel, with LREE enriched than HREE, and show gradual increase of negative Eu anomaly from basalt to dacite and rhyolite, suggesting comagmatic fractional crystallization with minor effects of assimilation and magma mixing. Andesitic rocks are assumed medium-K orogenic andesites that formed in the tectomagmatic environment of subduction zone under normal continental margin arc.

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Illusionism and Enlightment of the Magic Lantern Images - On the Scientific and Technological Development of the pre-modern optical instrument, Magic Lantern and the Transition of Its Images - (마술환등 영상의 환상성과 계몽성 근대 영상기구 마술환등의 과학기술적 발전과 영상문화의 변화)

  • LEE, Sang-Myon
    • Korean Association for Visual Culture
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    • v.17
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    • pp.65-92
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    • 2011
  • This thesis investigates the complex functions of the magic lantern in illusionism and enlightment which was the most popular visual media and the direct ancestor of cinema. Especially, the thesis focuses on the characteristics of magic lantern's images which had been varied with the scientific and technological development. During the early period of the magic lantern, from the late 18th century to the beginning of the 19th century, it frightened viewers by showing magic images with ghosts and spectres, 'phantasmagoria', and wondered with images of natural catastropes and interesting stories like fables and fairy tales, which fulfilled the entertainment function. Since the mid 19th century the magic lantern began to show not only pictures of the 'scientific themes' on the earth, nature and human, but also them of the ethnological on the far, exotic worlds like Africa, Amazon and Syberia etc. from the European perspective. These contents conducted the educative function and contributed to the process of Enlightment to the peoples in the pre-modern age. The two functions of the magic lantern such as entertainment and education had been neither historically followed, nor clearly divided, but the one was predominant according to the development of lantern techniques as well as the changes of the world view and the culture of the time. The entertainment function of the magic lantern based on the visual fantacy did exist in the late 19th century further, and also in the late industrial society, even in the age of highly developed science and technology, viewers want rather 're-enchantment' by illusionism than facts and truths on the reality. This is an essential characteristic of the moving image media, as it had already been presented in the images of the magic lantern.

Petrological Study on the Cretaceous Volcanic Rocks in the southwest Ryeongnam Massif: (1) the Mt. Moonyu volcanic mass, Seungju-gun (영남육괴 남서부에 분포하는 백악기 화산암류에 대한 암석학적 연구: (1) 승주군 문유산 화산암복합체)

  • Kim, Young-La;Koh, Jeong-Seon;Lee, Jeong-Hyun;Yun, Sung-Hyo
    • The Journal of the Petrological Society of Korea
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    • v.17 no.2
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    • pp.57-82
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    • 2008
  • The volcanic sequence of the late Cretaceous Moonyu volcanic mass which distributed in the southwestern part of Ryeongnam massif, can be divided into felsic pyroclastic rocks, andesite and andesitic pyroclastic rocks, rhyolite in ascending order. The earliest volcanic activity might commence with intermittent eruptions of felsic magma during deposition of volcaniclastic sediments. Explosive eruptions of felsic pyroclastic rocks began with ash-falls, to progressed through pumice-falls and transmitted with dacitic to rhyolitic ash-flows. Subsequent andesite and andesitic pyroclastic rocks were erupted and finally rhyolite was intruded as lava domes along the fractures near the center of volcanic mass. Petrochemical data show that these rocks are calc-alkaline series and have close petrotectonic affinities with subduction-related continental margin arc volcanic province. Major element compositions range from medium-K to high-K. Petrochemical variation within the volcanic sequence can be largely accounted for tractional crystallization processes with subordinate mixing. The most mafic rocks are basaltic andesite, but low MgO and Ni contents indicate they are fractionated by fractional crystallization from earlier primary mafic magma, which derived from less than 20% partial melting of ultramafic rocks in upper mantle wedge. Based on the stratigraphy, the early volcanic rocks are zoned from lower felsic to upper andesitic in composition. The compositional zonation of magma chamber from upper felsic to lower andesitic, is interpreted to have resulted from fractionation within the chamber and replenishment by an influx of new mafic magma from depth. Replenishment and mixing is based on observations of disequilibrium phenocrysts in volcanic rocks. REE patterns show slight enrichment of LREE with differentiation from andesite to rhyolite. Rhyolite in the final stage can be derived from calc-alkaline andesite magma by fractional crystallization, but it might have underwent crustal contamination during the fractional crystallization.

Effect of Carbon Dioxide Concentration, Temperature, and Relative Drought on Growth Responses and Yield in Spring Potato (Solanum tuberosum L.) (이산화탄소와 온도 그리고 한발 영향에 따른 감자의 생육과 수량반응)

  • Lee, Yun-Ho;Cho, Hyeoun-Suk;Kim, Jun-Hwan;Sang, Wan-Gyu;Shin, Pyong;Baek, Jae-Kyeong;Seo, Myung-Chul
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.20 no.2
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    • pp.149-158
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    • 2018
  • Agriculture is strongly influenced by climate change such as increased temperature and carbon dioxide ($CO_2$). This study describes the effects of climate change elevated $CO_2$, temperature, and relative drought on growth responses and yield in potato (Solanum tuberosum L.). The assessment was conducted for spring seasons in Soil-Plant-Atmosphere Research (SPAR) chamber at National Institute of Crop Science (NICS). Potatoes exhibit a positive response to $CO_2$ enrichment but water stress primarily reduces potato canopy and tuber yield. Elevated $CO_2$ and temperature increased both dry weight and tuber yield. Elevated $CO_2$ and temperature influenced SPAR 2 plants to a larger, and tuber increased yield up to 28% of than in SPAR 1(30-year average temperature at 450 ppm of $CO_2$). Our study findings indicate that tuber yield increase in potato under high $CO_2$ concentration was due to an increase in the size of individual tubers rather than in the number of the tubers per plant. On other hand, SPAR 3(30-year average temperature $+2.8^{\circ}C$ at 700 ppm of $CO_2$ under water stress) was lower than SPAR 2(30-year average temperature $+2.8^{\circ}C$ at 700 ppm of $CO_2$) nearly 56% of tuber yield due to drought. The results confirm potato drought sensitivity in terms of yield response. The experiment also showed that, in the conditions of climate change, climate change scenarios that improve cropping systems with potato.

Growth and Useful Component of Angelica gigas Nakai under High Temperature Stress (고온 스트레스에 따른 참당귀의 생육 및 유용성분 특성)

  • Jeong, Dae Hui;Kim, Ki Yoon;Park, Sung Hyuk;Jung, Chung Ryul;Jeon, Kwon Seok;Park, Hong Woo
    • Korean Journal of Plant Resources
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    • v.34 no.4
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    • pp.287-296
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    • 2021
  • Recently, the pace of global climate change has tremendously increased, causing extreme damage to crop production. Here, we aimed to examine the growth characteristics and useful components of Angelica gigas under extreme heat stress, providing fundamental data for its efficient cultivation. Plants were exposed to various experimental temperatures (28℃, 34℃, and 40℃), and their growth characteristics and content of useful components were analyzed. At the experimental site, the ambient and soil temperature were 19.38℃ and 21.34℃, ambient and soil humidity were 81.3 % and 0.18 m3/m3, solar radiation was 162.05 W/m2. Moreover, the soil was sandy-clay-loam (pH 6.65), with 2.66% organic matter, 868.52 mg/kg soil available phosphate, and 0.14% nitrogen. Values of most growth characteristics, including the survival rate (85%), plant height (38.66cm), and fresh and dry weight (41.3 g and 14.24 g), were the highest at 28℃. Although the highest content of useful components was observed at 34℃ (3.24%), there were no significant differences across temperatures. Growth characteristics varied across temperatures due to detrimental effects of heat stress, such as accelerated tissue aging, reduced photosynthesis, and delay of growth. Similar content of useful components across temperatures may be due to poor accumulation of anabolic products caused by impaired growth at extremely high temperatures.