• 제목/요약/키워드: Thin-section

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Characteristics of the Copper Mineralization in Tsogttsetsii Area, Mongolia (몽골 촉트체치 지역의 동 광화작용 특성)

  • Davaasuren, Otgon-Erdene;Lee, Bum Han;Kim, In Joon;Ryoo, Chung-Ryul;Heo, Chul-Ho
    • Journal of the Mineralogical Society of Korea
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    • 제29권1호
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    • pp.23-34
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    • 2016
  • Tsogttsetsii area, an intrusive complex associated with Cu porphyry mineralization, is located in the Gurvansaikhan island arc terrane of the Central Asian Orogenic belt, Southern Mongolia. We performed a reconnaissance survey in Tsogttsetsii area. Cu mineralization in Tsogttsetsii area is porphyry Cu type related with alkali granite intruded in Permian. Mineralogical and textural properties of the ores and associated minerals were analyzed using X-ray diffraction, thin section petrography, and Scanning electron microscopy-Energy dispersive spectroscopy (SEM-EDS). Ore minerals identified in polarizing microscope are magnetite, pyrite and bornite. Propylitic alteration zone occurs broadly in the area where malachite occurrences are shown to be spread intensively in alkali granite area. Quartz, sericite, chlorite and epidote were observed in the alteration zone samples. As results of XRD and SEM-EDS analysis, samples of copper oxides were composed mainly of malachite, cuprite and small amounts of quartz. Average and maximum Cu contents of samples collected from malachite occurrences area are 759 ppm and 6190 ppm, respectively. The characteristics of mineralization in Tsogttsetsii area is similar to Oyu Tolgoi Cu-Au (Mo) deposit and Tsagaan Suvarga Cu-Mo deposit which are 56 km south and 120 km northeast from Tsogttsetsii area, respectively. Characteristics of the study area, such as the geology, tectonic environment, lithology, mineralization, and alterations of the rocks within the survey area, resemble the characteristics of other porphyry deposits. Therefore further exploration including Induced Polarization (IP) survey for identifying subsurface orebody is required.

The Consideration for Optimum 3D Seismic Processing Procedures in Block II, Northern Part of South Yellow Sea Basin (대륙붕 2광구 서해분지 북부지역의 3D전산처리 최적화 방안시 고려점)

  • Ko, Seung-Won;Shin, Kook-Sun;Jung, Hyun-Young
    • The Korean Journal of Petroleum Geology
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    • 제11권1호
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    • pp.9-17
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    • 2005
  • In the main target area of the block II, Targe-scale faults occur below the unconformity developed around 1 km in depth. The contrast of seismic velocity around the unconformity is generally so large that the strong multiples and the radical velocity variation would deteriorate the quality of migrated section due to serious distortion. More than 15 kinds of data processing techniques have been applied to improve the image resolution for the structures farmed from this active crustal activity. The bad and noisy traces were edited on the common shot gathers in the first step to get rid of acquisition problems which could take place from unfavorable conditions such as climatic change during data acquisition. Correction of amplitude attenuation caused from spherical divergence and inelastic attenuation has been also applied. Mild F/K filter was used to attenuate coherent noise such as guided waves and side scatters. Predictive deconvolution has been applied before stacking to remove peg-leg multiples and water reverberations. The velocity analysis process was conducted at every 2 km interval to analyze migration velocity, and it was iterated to get the high fidelity image. The strum noise caused from streamer was completely removed by applying predictive deconvolution in time space and ${\tau}-P$ domain. Residual multiples caused from thin layer or water bottom were eliminated through parabolic radon transform demultiple process. The migration using curved ray Kirchhoff-style algorithm has been applied to stack data. The velocity obtained after several iteration approach for MVA (migration velocity analysis) was used instead or DMO for the migration velocity. Using various testing methods, optimum seismic processing parameter can be obtained for structural and stratigraphic interpretation in the Block II, Yellow Sea Basin.

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Discrete Optimum Design of Sinusoidal Corrugated Web Girder (사인형 주름웨브보의 이산화 최적구조설계)

  • Shon, Su Deok;Yoo, Mi Na;Lee, Seung Jae
    • Journal of Korean Society of Steel Construction
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    • 제24권6호
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    • pp.671-682
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    • 2012
  • The use of sinusoidal corrugated web girder for the box-type girders and gable steel main frames has recently been increasing very much. The reasons are that the thin web of the girder affords a significant weight reduction compared with rolled beam and welded built-up girder, and that corrugation prevents the buckling failure of the web. Improvements of the automatic fabrication process makes mass production of the corrugated web and unit possible, and applications of this girder have been extended considerably. Thus, the research for the optimum design processer considering the production data is needed practically. For doing this research, we develope the discrete optimum structural design program in consideration of production list data for the research, and the program apply to the single girder under the uniform load and the concentrated load as numerical example. We consider objective function as minimum weight of the girder, and use slenderness ratio, stress of flanges and corrugated web, and the girder deflection as the constraint functions. And also the Genetic Algorithms is adopted to search the global minimum point by using the production list as a discrete design variable. Finally, to verify the optimality of the design, we conduct a comparison of the results of the discrete optimum design with those of the continuous one, and also analyze the characteristics of the optimum cross-section.

Material Characteristics and Clay Source Interpretation of Crucibles in Baekje Kingdom Excavated from the Ssangbukri Site in Buyeo, Korea (부여 쌍북리 유적 출토 백제 도가니의 재료학적 특성과 원료의 산지해석)

  • Kim, Ji-Young;Park, Jin-Young;Park, Dae-Sun;Lee, Chan-Hee
    • Journal of Conservation Science
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    • 제26권1호
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    • pp.1-12
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    • 2010
  • The crucibles of Baekje Kingdom from the Ssangbukri Site which were used for glass and metal melting had light brown, grayish blue and grayish brown colored bodies. In thin section, the crucibles contained numerous quartz grains and pottery fragments. The surface was covered with fine grained quartz for thermal resistance. Based on decomposition of mica group minerals and formation of mullite detected by X-ray diffraction analysis, it was inferred that all crucibles have been fired over $1,000^{\circ}C$. It was also found that firing temperature has exceeded $1,100^{\circ}C$ in some crucibles because feldspar was not detected. The maximum temperature was assumed at $1,200^{\circ}C$. The magnetic susceptibility values and geochemical characteristics sorted out the crucibles into two groups that differed from the characteristics of the local soils. This reflected geological setting of the site where the alluvium was formed from two kinds of surrounding rock masses, granite gneiss and biotite granite. However, the local soils had similarities with the crucibles in weathering degree and geochemical behavior of major elements. In consequence, it was considered that the raw clay of the crucibles was supplied from the local area of the site.

Study on the Applicability of High Frequency Seismic Reflection Method to the Inspection of Tunnel Lining Structures - Physical Modeling Approach - (터널 지보구조 진단을 위한 고주파수 탄성파 반사법의 응용성 연구 - 모형 실험을 중심으로 -)

  • Kim, Jung-Yul;Kim, Yoo-Sung;Shin, Yong-Suk;Hyun, Hye-Ja;Jung, Hyun-Key
    • Journal of Korean Tunnelling and Underground Space Association
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    • 제2권3호
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    • pp.37-45
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    • 2000
  • In recent years two reflection methods, i.e. GPR and seismic Impact-Echo, are usually performed to obtain the information about tunnel lining structures composed of concrete lining, shotcrete, water barrier, and voids at the back of lining. However, they do not lead to a desirable resolution sufficient for the inspection of tunnel safety, due to many problems of interest including primarily (1) inner thin layers of lining structure itself in comparison with the wavelength of source wavelets, (2) dominant unwanted surface wave arrivals, (3) inadequate measuring strategy. In this sense, seismic physical modeling is a useful tool, with the use of the full information about the known physical model, to handle such problems, especially to study problems of wave propagation in such fine structures that are not amenable to theory and field works as well. Thus, this paper deals with various results of seismic physical modeling to enable to show a possibility of detecting the inner layer boundaries of tunnel lining structures. To this end, a physical model analogous to a lining structure was built up, measured and processed in the same way as performed in regular reflection surveys. The evaluated seismic section gives a clear picture of the lining structure, that will open up more consistent direction of research into the development of an efficient measuring and processing technology.

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A Morphological Comparison of Bamboo Zephyr Produced from Phyllostachys nigra var. henonis and Indonesian Gigantochloa apus (국산 솜대와 인도폐시아산 TALI를 이용한 대나무 Zephyr의 형태적 특성 비교)

  • Kim, Yu-Jung;Jung, Ki-Ho;Park, Sang-Jin;Roh, Jeang-Kwan
    • Journal of the Korean Wood Science and Technology
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    • 제29권2호
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    • pp.84-90
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    • 2001
  • To investigate morphological characteristics of zephyr produced from two bamboo species, Phyllostachys nigra var. henonis and Gigantochloa apus, basic anatomic properties were examined by scanning electron microscopy and image analysis. According to SEM observation, zephyr from Phyllostachys nigra var. henonis was not of uniform in shape and showed macro crack between vascular bundle sheaths. This may be attributes to the sclerenchymatous fibers connected closely, thus resulting in difficult separation of intercellular layer. Zephyr from Gigantochloa apus was of uniform in shape, which may be caused by easy separation of intercellular layer of sclerenchymatous fibers having thin cell wall and large cell lumen. By image analysis in cross section of two species, the ratio of vascular bundle sheaths and cell wall ratio of sclerenchymatous fibers were examined. The ratio of vascular bundle sheaths in Phyllostachys nigra var. henonis was lower than that in Gigantochloa apus. However, cell wall ratio of sclerenchymatous fibers in Phyllostachys nigra var. henonis was higher than that in Gigantochloa apus.

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Regional Distribution of Isotropy Magnetic Property of Dual-type Giant Magnetoresistance-Spin Valve Multilayer (이중구조 거대자기저항-스핀밸브 박막의 자기등방성 영역분포에 관한 연구)

  • Khajidmaa, Purevdorj;Lee, Sang-Suk
    • Journal of the Korean Magnetics Society
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    • 제23권6호
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    • pp.193-199
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    • 2013
  • The regional distribution of magnetic isotropy depending on the post annealing condition for the dual-type structure GMR-SV (giant magnetoresistance-spin valve) of NiFe/Cu/NiFe/IrMn/NiFe/Cu/NiFe multilayer was investigated. The rotation of in-plane ferromagnetic layer induced by controlment of the post annealing temperature inside of the vacuum chamber. The magnetoresistive curves of a dual-type IrMn based GMR-SV depending on the direction of the magnetization easy axis of the free layer and the pinned layer are measured by between $0^{\circ}$ and $360^{\circ}$ angles for the applied fields. The optimum annealing temperature having a steady and isotropy magnetic sensitivity of 1.52 %/Oe was $107^{\circ}C$ in the rotational section of $0{\sim}90^{\circ}$. By investigating the switching process of magnetization for an arbitrary measuring direction, the in-plane orthogonal magnetization for the dual-type GMR-SV multilayer can be used by a high sensitive biosensor for detection of magnetized micro-beads.

Performance and SILC Characteristics of Flash Memory Cell With Ultra thin $N_2O$ Annealed Tunneling Oxide (초박막의 $N_2O$ 어닐링한 터널링 산화막을 갖는 Flash Memory Cell의 SILC 특성 및 성능)

  • Son, Jong-Hyoung;Chong, Jong-Wha
    • Journal of the Korean Institute of Telematics and Electronics D
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    • 제36D권10호
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    • pp.1-8
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    • 1999
  • In this paper, we have studies the transport mechanism and origin of SILC for the various thickness of wet oxide. Also, SILC characteristics of $N_2O$ annealed oxide was included in this study. We made the flash memory cell with $N_2O$ annealed oxide of 60Athick under $0.25{\mu}m$ design rule, and measured the characteristics of the cell. As a result, we have found that the origin of SILC is due to the trap formed inside of the oxide layer by electrical stress. And we reached the conclusion that the transport mechanism of SILC is ruled by the modified F-N tunneling if the electric field is lower than 8MV/cm or typical F-N tunneling if the electric field is higher than 8MV/cm. We could also confirm the fact that $N_2O$ annealed oxide of 60Athick have an improved resistance effect against SILC. In case that we apply $N_2O$ annealed oxide of 60Athick to the flash memory, we could confirm $10^6$ times endurance and more than 10 years drain disturb, and could get 8V programmable flash memory characteristics.

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The Clinical Manifestations of the Five Cases of Lymphangitic Carcinomatosis of the Lung Presented as Diffuse and Interstitial Disease (미만성 간질성 폐질환으로 발현한 폐장의 암종성 림프관염 환자 5예에 대한 임상적 고찰)

  • Sung, Young-Joo;Choi, Soo-Jeon;Lee, Bong-Chun;Kim, Dong-Soon;Seo, Yeon-Lim
    • Tuberculosis and Respiratory Diseases
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    • 제39권1호
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    • pp.55-61
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    • 1992
  • Background: The lung is the most common site of metastasis and usually it manifests as a single or multiple nodules in chest X-ray. But less commonly the cancer spreads through the lymphatics and X-ray shows diffuse reticulonodular densities. Sometimes, patient is presented with respiratory symptoms only with interstitial lung infiltration before the signs of primary tumor and in that cases, the differential diagnosis with other interstitial lung disease is required. We have experienced 5 such cases, who were diagnosed as lymphangitic carcinomatosis by transbronchial lung biopsy. Methods: Clinical manifestation, pulmonary function test, modified thin section CT, bronchoalveolar lavage and transbronchial lung biopsy were done. Results: The primary tumor was gastric cancer in 3, lung cancer in 2. Pulmonary function test showed restrictive pattern with low DLco in 2 patients and obstructive pattern in one. Bronchoalveolar lavage showed lymphocytosis in 4 patients and malignant cells were found in one patient. Transbronchial lung biopsy revealed malignant cells localized to the lymphatics (peribronchial, perivascular and perialveolar). Cell type was adenocarcinoma in 4 and squamous cell carcinoma in one. Conclusion: Rarely lymphangitic carcinomatosis can be presented as diffuse interstitial lung disease and easily diagnosed by transbronchial lung biopsy.

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Petrology of Puu Oo lavas from the Big Island, Hawaii (하와이, 빅 아일랜드의 푸우오오 용암에 대한 암석학적 연구)

  • Kwon, Suk-Bom;Jang, Yun-Deuk;Park, Byeong-Jun;Kim, Yeong-Kyoo;Kim, Jung-Jin
    • The Journal of the Petrological Society of Korea
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    • 제16권4호
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    • pp.217-232
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    • 2007
  • The Puu Oo eruption in Hawaii since 1983 is one of the largest eruptions on Hawaii's volcanic history with prominent compositional variation ($5.6{\sim}10.1wt.%$ in MgO content). Although intense researches of Hawaiian eruption have been conducted for recent years, there is no up-to-date study on Puu Oo lavas that is erupting hot lavas today. in oder to obtain basic information on the geological characteristics of the eruption including any noticeable change in its petrological trend and magma dynamics, we applied several geological approaches such as field survey, systematic sampling, petrography, mineralogy, and geochemistry. Clinopyroxene and Plagioclase phenocrysts are rarely observed on the thin section, however Olivine crysts are much more obvious in the study area. It indicates that Puu Oo is early stage of magma differentiation. Variation diagram of whole rock composition shows that the elements such as $TiO_2,\;Al_2O_3,\;SiO_2$ and $Na_2O$ decrease with increasing MgO. In the trace element Sr, Y Zr and V versus $K_2O$, P18, P19 samples are plotted in primitive area. Variations of the Ni contents during $2003{\sim}2006$ may suggest a sudden change in magma composition probably caused by new magma injection.