• Title/Summary/Keyword: 철운석

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Characteristics of Salt Weathering and Environmental Variation on the Usuki Stone Buddha Statues in Oita, Japan (일본 오이타현 우스키 마애불상군의 환경변화와 염풍화 특성)

  • Cho, Ji Hyun;Lee, Chan Hee
    • Economic and Environmental Geology
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    • v.53 no.6
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    • pp.677-685
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    • 2020
  • The host rock of the Usuki Stone Buddha Statues is dark gray welded tuff involved the Aso-4 pyroclastic flow sediments. This Buddha Statues are processing chlorosis from rainfall flowing above and underground water which were urgently needed for conservation measurement. White precipitates, the main source of salt weathering, on the surface of the Buddha Statues are mainly consisted of thenardite, gypsum and dolomite. Extraction experiment result shows that thenardite was dissolved at the beginning of stirring and then redissolved after 4 hours, and gypsum was detected until stirring for 2 hours, and then dissolved after stirring for 4 hours. As a result of monitoring the microclimate environment for 11 months to determine the recrystallization environment of white precipitates, the phase transition between thenadite and mirabilite appears widely in spring, and is maintained in an aqueous solution due to high temperatures in summer and fall. In winter, mirabilite is shown the widest by decreasing temperature. Therefore we requires details monitoring for blocking water transfer port and solved humidity environment in shelter.

Olivine Synthesis Using Stainless Steel Tube (스테인리스강관을 이용한 감람석 합성)

  • Gi Young Jeong
    • Korean Journal of Mineralogy and Petrology
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    • v.36 no.4
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    • pp.337-343
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    • 2023
  • Olivine is a complete solid solution of fayalite and forsterite that is abundant in Earth and extraterrestrial materials such as rocky planets, meteorites, asteroids, and interplanetary dust. Due to the wide range of olivine compositions, diverse olivine standards are required for quantitative mineralogical analysis of olivine-bearing materials. Olivine standards were synthesized using an electric furnace and stainless steel tubes at temperatures ranging from 1000~1100 ℃. Overall, olivine was synthesized covering the full range of composition, with some synthetic impurities and unreacted material. The synthesized olivine showed a linear increase in the unit cell dimension in proportion to the molar ratio of fayalite in the starting materials, and the diffraction intensity was consistent with that of natural olivine. However, iron-rich synthetic olivine samples tend to have a higher content of impurity, suggesting that not all synthetic olivine can be used as a standard material yet, and improvements in the synthesis process, such as using high purity starting materials and control of reaction time and temperature, are required.

The Effects of Carbonate Minerals in Gully-pot Sediment on the Leaching Behavior of Heavy Metals Under Acidified Environment (우수관퇴적물에 함유된 탄산염광물이 산성환경에서의 중금속 용출거동에 미치는 영향 평가)

  • 이평구;유연희
    • Economic and Environmental Geology
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    • v.35 no.3
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    • pp.257-271
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    • 2002
  • One of the main interests in relation to heavily contaminated gully-pot sediment in urban area is the short term mobility of heavy metals, which depends on the pH of acidic rainwater and on the buffering effects of carbonate minerals. The buffering effects of carbonates are determined by titration (acid addition). Leaching experiments are carried out in solutions with variable initial HN03 contents for 24h. The gully-pot sediment appears to be predominantly buffered by calcite and dolomite. In case of sediment samples, which highly contain carbonates, pH decreases more slowly with increasing acidity. On the other hand, for the sediment samples, which less contain carbonate minerals, pH rapidly drops until it reaches about 2 then it decreases slowly. The leaching reactions are delayed until more acid is added to compensate for the buffering effects of carbonates. The Zn, Cu, Pb and Mn concentrations of leachate rapidly increase with decreased pH, while Cd, Co, Ni, Cr and Fe dissolutions are very slow and limited. The solubility of heavy metals depends not only on thc pH values of leachatc but also on the speciation in which metals are associated with sediment particles. In slightly to moderately acid conditions, Zn, Cd, Co, Ni and Cu dissolutions become increasingly important. As deduced from leaching runs, the relative mobility of heavy metals at pH of 5 is found to be: Zn > Cd > Co > Ni > Cu » Pb > Cr, suggesting that moderately acid rainwater leach Zn, Cd, Co, Ni and Cu from thc contaminated gully-pot sediment, while Pb and Cr would remain fixed. The buffering effects of Ca- and Mg-carbonates play an important role in delaying as well as limiting the leaching reactions of heavy metals from highly contaminated gully-pot sediment. The extent of such a secondary environmental pollution will thus depends on how well the metals in sediment can be leached by somewhat acidic rain water. Changes in the physicochemical environments may result in the severe environmental pollution of heavy metals. These results are to be taken into account in the management of contaminated sediments during rainstorms.

Geographic Distribution Analysis of Lunar In-situ Resource and Topography to Construct Lunar Base (달 기지 건설을 위한 달 현지 자원 및 지형의 공간 분포 분석)

  • Hong, Sungchul;Kim, Young-Jae;Seo, Myungbae;Shin, Hyu-Soung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.6
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    • pp.669-676
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    • 2018
  • As the Moon's scientific, technological, and economic value has increased, major space agencies around the world are leading lunar exploration projects by establishing a road map to develop lunar resources and to construct a lunar base. In addition, as the lunar base construction requires huge amounts of resources from the Earth, lunar in-situ construction technology is being developed to produce construction materials from local lunar resources. On the other hand, the characteristics of lunar topography and resources vary spatially due to the crustal and volcanic activities inside the Moon as well as the solar wind and meteorites from outside the Moon. Therefore, in this paper, the geospatial analysis of lunar resource distribution was conducted to suggest regional consideration factors to apply the lunar in situ construction technologies. In addition, the lunar topographic condition to select construction sites was suggested to ensure the safe landing of a lunar lander and the easy maneuvering of a rover. The lunar topographic and resource information mainly from lunar orbiters were limited to the lunar surface with a low spatial resolution. Rover-based lunar exploration in the near future is expected to provide valuable information to develop lunar in situ construction technology and select candidate sites for lunar base construction.

Efficacy of Acupuncture in Treating Upper Abdominal Pain in Cancer Patients: Study Protocol for A Randomized Controlled Pilot Clinical Trial (암환자의 상복부 통증 치료에 대한 침의 효과: 무작위배정 대조군 연구 예비임상시험 프로토콜)

  • Jung, Jin-Yong;Lee, Hyun-Jong;Seo, Jung-Chul;Min, Bo-Mi;Cho, Min-Su;Shin, Im-Hee;Roh, Woon-Seok;Kwak, Min-Ah
    • Korean Journal of Acupuncture
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    • v.31 no.1
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    • pp.33-39
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    • 2014
  • Objectives : This study was designed to evaluate the feasibility of further acupuncture research as an effective and safe treatment for reducing cancer-related upper abdominal pain in patients treated with Neurolytic celiac plexus block(NCPB). Methods : This study is a randomized controlled pilot clinical trial of 3-week duration. Fourteen patients will be recruited and randomly allocated to 2 groups: an acupuncture plus NCPB group(experimental group) and a NCPB group(control group). All patients will undergo one session of NCPB, but only the experimental group will receive three acupuncture sessions a week for 2 weeks(6 in total). The primary outcome will be measured using the visual analogue scale, and the secondary outcome will be measured using the Painvision system and the consumption of additional analgesics. Assessments will be made at baseline and at 1, 2, and 3 weeks thereafter(that is, the 3-week assessment will be made 1 week after treatment cessation). Conclusions : This clinical trial will inform the design of a full-scale trial. The outcomes will provide information to facilitate the incorporation of acupuncture into existing pain management methods such as NCPB in the treatment of cancer-related upper abdominal pain patients.