• Title/Summary/Keyword: Historical eruption

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ALVEOLAR CLEFT GRAFT (치조열 골이식)

  • Jun, Sang-Ho;Padwa, Bonnie L.;Jung, Young-Soo
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.31 no.3
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    • pp.267-272
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    • 2009
  • Bone grafting the alveolar cleft allows for stability and continuity of the dental arch, provides bone for eruption of permanent teeth or placement of dental implants, and gives support to the lateral ala of the nose. Closure of residual oronasal fistula can occur simultaneously. Repair of alveolar clefts can occur at a variety of stages defined as primary, early secondary, secondary, and late. Most centers perform this surgery as secondary bone grafting. Autogenous bone provides osteogenesis, osteoinduction and conduction and is recommended for grafting to the cleft alveolus and several donor sites are available. The surgeon should select the best flap design considering the amount of mucosa available, blood supply and tension-free closure, and the extent of the oronasal communication. The authors provide a comprehensive understanding of alveolar clefts and their repair by reviewing the historical perspective, objectives for treatment, timing, source of graft, presurgical orthodontics, surgical techniques, postoperative care, and complications.

Geochemical Composition of Volcanic Ash from Historical Eruptions of Mt. Baekdu, Korea (역사시대에 분화한 백두산 화산재의 화학 성분)

  • Yun, Sung-Hyo;Koh, Jeon Seon;Chang, Cheolwoo
    • The Journal of the Petrological Society of Korea
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    • v.27 no.1
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    • pp.37-47
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    • 2018
  • Volcanic ash samples of historical eruptions from Mt. Baekdu were analyzed for major oxides, trace and rare earth elements by a variety of analytical techniques. The results indicate that the ashes consist of approximately 58.8~71.1 wt.% $SiO_2$, 9.6~16.8 wt.% $Al_2O_3$, 4.5~6.9 wt.% $Fe_2O_{3t}$, 0.1~1.7 wt.% MgO, 0.3~1.6 wt.% CaO, 5.2~6.3 wt.% $Na_2O$, 4.3~5.9 wt.% $K_2O$ and less than 1.2 wt.% $TiO_2$. Thirty two trace metals including Ba, Cu, Cr. Co, Ni, Sr, V, Zn, and Zr were analyzed. The ashes can be divided two groups: group A(1 ka Millennium pumice, 1668 and $190{\underline{3}}$ pumice) and group B(1702 pumice) according to the relative enrichment of HREEs. The abundances of heavy metals such as Cu, Co, Mn, and Zn were relatively low. As compared to the Sakurajima volcanic ash, Baekdusan volcanic ash has low concentrations of Y, Nb, Pb, U, Sc, V, Ni and Cu and high concentrations of Zr, Ba, Hf, Cr, Co, Zn and rare-earth (except Eu).

Multiple Outbursts of a Short-Periodic Comet 15P/Finlay

  • Ishiguro, Masateru;Kuroda, Daisuke;Kim, Yoonyoung;Kwon, Yuna;Hanayama, Hidekazu;Miyaji, Takeshi;Honda, Satoshi;Takahashi, Jun;Watanabe, Jun-Ichi
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.1
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    • pp.61.2-61.2
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    • 2015
  • 15P/Finlay is one of the Jupiter-Family Comets that has long been known since the late 19 century. The comet maintains the perihelion around 1.0 AU over a century, without showing any prominent activities (i.e. fragmentation or eruption) since the discovery. According to reports in unpublished observations, the comet exhibited an outburst in the middle of 2014 December. We conducted a imaging observation of 15P/Finlay just after the report, from 2014 December 23 to 2015 February 18 using three telescopes (the Okayama Astrophysical Observatory 50-cm telescope, the Ishigakijima Astronomical Observatory 105-cm telescope, and the Nishi-Harima Astronomical Observatory 2-m telescope), which constitute a portion of the OISTER (an inter-university observation network in the optical and infrared wavelengths). As a result of the frequent observations, we witnesses the second outburst around UT 2015 January 16. Such cometary outbursts draw the attention to researchers on ground that they could offer insight into the internal structure of comets, following a historical outburst occurred at 17P/Holmes on 2007 October 23. Although cometary outbursts have been often reported mostly in unpublished observations or unreviewed reports, it should be emphasized that there are not a sufficient number of astrophysical research which characterizes the physical properties by observing the aftermaths. This presentation provides a new observational result of 15P/Finlay outburst. Based on the morphological development of the dust cloud as well as the near-nuclear magnitude, we will derive the kinetic energy of the outburst. Finally we plan to compare the results of 15P/Finlay with those of analogical events at 17P/Holmes and P/2010 V1 (Ikeya-Murakami).

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A study on Vietnamese Women in Korean Films and TV Dramas (한국 영화와 TV 드라마에 나타난 베트남 여성상 고찰)

  • Yook, Sang Hyo
    • The Southeast Asian review
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    • v.20 no.2
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    • pp.73-99
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    • 2010
  • To properly answer the question 'Why have Vietnamese Women kept appearing in Korean Films and TV dramas?', We need to induce Postcolonial discourse along with historical and cultural similarities between Korea and Vietnam. It is because the relationship of two countries can be defined as a neocolonialism specially in view of economic relationship. Koreans need to locate themselves on the superior position by othering Vietnamese women, who are close enough to be compared and also distant enough to be othered. This paper is intended to bring their being in Korean films and TV dramas under the light of postcolonial discourse. According to the postcolonial concepts such as ambivalence, stereotyping and subaltern, Korean films and TV dramas are classified into three groups, which are Vietnam war melodramas, Horror movies based in Vietnam, and TV dramas with Vietnamese brides. War melodramas have been othering Vietnamese woman through ambivalence of the fear of Vietcom warrior and the fascination of exotic beauty. Horror movies, produced about 10 years later, brought the Vietnamese women back to Korean audience, stereotyping them into ghosts, which are incarnated through the suppression and eruption of sexual desire. The third group consists mainly of TV dramas. Their story usually evolves around Vietnamese brides migrating into Korea. The women are forced into the position of Subaltern, not representing themselves in their own voices. Facing multi-cultural society, our visual media are requested to modify their neocolonial approach of presenting Vietnamese women. To accomplish the goal, they have to find ways of storytelling to show the women in their everyday lives and help them to speak for themselves.

Scenario-based Flood Disaster Simulation of the Rim Collapse of the Cheon-ji Caldera Lake, Mt. Baekdusan (시나리오에 따른 백두산 천지의 외륜산 붕괴에 의한 홍수재해 모의)

  • Lee, Khil-Ha;Kim, Sang-Hyun;Choi, Eun-Kyeong;Kim, Sung-Wook
    • The Journal of Engineering Geology
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    • v.24 no.4
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    • pp.501-510
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    • 2014
  • Volcanic eruptions alone may lead to serious natural disasters, but the associated release of water from a caldera lake may be equally damaging. There is both historical and geological evidence of the past eruptions of Mt. Baekdusan, and the volcano, which has not erupted for over 100 years, has recently shown signs of reawakening. Action is required if we are to limit the social, political, cultural, and economic damage of any future eruption. This study aims to identify the area that would be inundated following a volcanic flood from the Cheon-Ji caldera lake that lies within Mt. Baekdusan. A scenario-based numerical analysis was performed to generate a flood hydrograph, and the parameters required were selected following a consideration of historical records from other volcanoes. The amount of water at the outer rim as a function of time was used as an upper boundary condition for the downstream routing process for a period of 10 days. Data from the USGS were used to generate a DEM with a resolution of 100 m, and remotely sensed satellite data from the moderate-resolution imaging spectroradiometer (MODIS) were used to show land cover and use. The simulation was generated using the software FLO-2D and was superposed on the remotely sensed map. The results show that the inundation area would cover about 80% of the urban area near Erdaobaihezhen assuming a 10 m/hr collapse rate, and 98% of the area would be flooded assuming a 100 m/hr collapse rate.

Geochemical Studies of the Trace Element of the Basalt in the Kilauea, Hawaii (킬라우에아 현무암의 미량원소에 대한 지구화학적 연구)

  • Park, Byeong-Jun;Jang, Yun-Deuk;Kwon, Suk-Bom;Kim, Jeong-Jin
    • Economic and Environmental Geology
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    • v.40 no.5
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    • pp.675-689
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    • 2007
  • Kilauea volcano's summit area was formed by continuous ind/or sporadic eruption activities for several hundreds years. In this study, we mainly focused on the trace elements characteristics through systematic sample rocks erupted from 1790 to September of 1982. Under the microscope it can be observed some main minerals such as olivine, clinopyroxene. and plagioclase with minor opaque minerals including Cr-spinel and ilmenite. Zr, V, Y, Ti elements show incompatible activities with MgO while Ni, Cr, Co elements show highly compatible properties. Elements like as Ba, Rb, Th, Sr, Nd are highly incompatible to show positive trends with $K_2O$. In the REE diagram LREE is more enriched than HREE suggesting typical Oceanic Island Basalt(OIB) type. It can be suggested that Sr have an effect on the fractionation of plagioclase from the kink in the $K_2O$ variation diagram. Y/Ho ratio diagram shows there was no fluids effect in the historical Kilauea volcano but Zr/Hf ratio diagram shows a significant difference between Kilauea lavas and PuuOo lavas. There are distinctive changes of trace element contents showing in particular abrupt changes of temporal variations between 1924 and 1954. Moreover, PuuOo lavas which had been erupted since 1983 follow these decreasing trends of trace element variation. Therefore, it is strongly suggested that these abrupt changes of trace elements trends result from the huge collapse geological event which formed Halemaumau crater in 1924 causing contamination effects of crustal contents into magma chamber and from the changes of parental magma composition injected into Kilauea volcano's summit magma reservoir.