• Title/Summary/Keyword: SiFe Sheet

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Analysis of fiber and pigment in Palsapumdo from Hyeonchungsa (현충사관리소 소장 팔사품도(八賜品圖)에 사용된 직물 · 종이 섬유 식별 및 안료 분석)

  • Park, Ji-Hee;Kim, So-Jin;Kim, Soon-Kwan
    • 보존과학연구
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    • s.32
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    • pp.75-87
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    • 2011
  • The materials analysis is important in conservation science for cultural assets since conservators can make appropriate decision of treatment and environment through understanding manufacturing, period and materials. Palsapumdo is the painting of Palsapum which was given by Yi Sun-shin from the emperor Shinjong in The Ming Dynasty. Palsapumdo painted with various pigments on the fabric has remained to adhere a sheet of lining paper. In this study, we carried out the fiber identification about the fabric and lining paper and the analysis of the pigments. This study identified a fabric and a lining paper and analised pigments for the painting. As a result of fabric analysis, it was confirmed as cotton because ribbon twists and shape of kidney bean in a cross section. After the analysis of lining paper, color changed to yellow by Graff "C" staining tests, and had short fiber and tracheid. Therefore, it is supposed to be a paper which is made of conifer pulp. In addition, the results of SEM-EDS, the pigments are indicated as Orpiment($As_2S_3$), Minium($Pb_3O_4$), Hematite($Fe_2O_3$), Emeraldgreen ($C_2H_3As_3Cu_2O_8$), Ultramarine [$2(Na_2O{\cdot}Al_2O_3{\cdot}2SiO_2){\cdot}Na_2S_2$], talc[$Mg_3Si_4O_{10}(OH)_2$], bariumsulfate($BaSO_4$) and brass.

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The characteristics of zircon as the evidence for post-magmatic remobilization of REE and HFSE in the northern Motzfeldt alkaline igneous complex, southern Greenland

  • Kim, Eui-Jun;Yang, Seok-Jun;No, Sang-Gun;Park, Sung-Won;Lee, Seung Ryeol;Kim, You-Dong;Jo, Jinhee
    • Geosciences Journal
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    • v.22 no.6
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    • pp.921-938
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    • 2018
  • The Motzfeldt intrusions in the Gardar Province, southern Greenland, split into syenitic plutonic and hypabyssal rocks, in which the latter include ring dykes and sheet intrusions. Sheet intrusions, considered as the source for rare earth elements (REE) and high field strength elements (HFSE), comprise sheets of peralkaline microsyenite (SPM), syenitic pegmatite (SP), and peralkaline microsyenite (PM). SP exhibits extremely high concentrations of REE and HFSE, which are positively correlated with increasing alkalinity from early towards late intrusion, caused by magmatic processes. In contrast, some of the SPM and PM are also significantly enriched in REE and HFSE, caused by post-magmatic fluids. The REE- and HFSE-rich phases in SP consist mainly of zircon and allanite with smaller amounts of pyrochlore in pseudomorph from the inferred eudialyte, whereas some of the PM and SPM consist of pyrochlore, REE-carbonate, and zircon in the matrix. The zircon grains in the Motzfeldt Sø Formation (MSF) syenite occur in interstitial spaces, exhibiting an association with magnetite and a bipyramidal form in texture. They are characterized by a highly fractured and embayed rim. Zircons from PM and SP are clearly enriched in Fe, Al, Ca, Na, Y, P, Hf, Y, P, Nb, Ta, and REE, and are depleted in Zr and Si in comparison with magmatic zircon. They also show a clear trend of higher LREE/HREE and $Eu/Eu^{\star}$ ratios, and lower $Ce/Ce^{\star}$ ratios, which define them as typical hydrothermal zircons. In contrast, zircons from the MSF syenite show a relatively lower LREE/HREE ratio and Eu and Ce anomalies of a similar magnitude compared with those from SP and PM. The occurrence and mineral composition of the zircon suggest that post-magmatic fluids have played an important role in the remobilization of REE and HFSE as well as the primary concentration of REE and HFSE, caused by magmatic processes.

Study of Electromagnetic Wave Absorption Properties with Particle Size in Soft Magnetic Alloy Powder (연자성 합금 분말의 입자크기에 따른 전자파 흡수 특성 비교)

  • Hong, S.H.;Sohn, K.Y.;Park, W.W.;Nam, J.M.;Moon, B.G.;Song, Y.S.
    • Journal of Powder Materials
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    • v.14 no.4
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    • pp.261-264
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    • 2007
  • The electromagnetic wave (EM) absorption properties of various particle size have been investigated in a sheet-type absorber using the $Fe_{73}Si_{16}B_{7}Nb_{3}Cu_{1}$ alloy powder. With decreasing the average particle size, the complex permeability (${\mu}_{r}$) and permittivity (${\varepsilon}_{r}$) increased and the matching frequency is shifted toward lower frequency. The fabricated EM wave absorbers showed permeability $2{\sim}6$, permittivity $17{\sim}23$ for a $-325{\sim}+400$ mesh sample, and the calculated power absorption was as high as 80% in the frequency range over 2 GHz.

Chemical weathering in King George Island, Antarctica

  • Jeong, Gi-Young
    • Proceedings of the Mineralogical Society of Korea Conference
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    • 2003.05a
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    • pp.66-66
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    • 2003
  • King George island, Antarctica, is mostly covered by ice sheet and glaciers, but the land area is focally exposed for several thousand years after deglaciation. For a mineralogical study of chemical weathering in the polar environment, glacial debris was sampled at the well-developed patterned ground which was formed by long periglaclal process. As fresh equivalents, recently exposed tills were sampled at the base of ice cliff of outlet glaciers and at the melting margin of ice cap together with fresh bedrock samples. Fresh tills are mostly composed of quartz, plagioclase, chlorite, and illite, but those derived from hydrothermal alteration zone contain smectite and illite-smectite. In bedrocks, chlorite was the major clay minerals in most samples with minor illite near hydrothermal alteration zone and interstratified chlorite-smectite in some samples. Smectite closely associated with eolian volcanic glass was assigned to alteration in their source region. Blocks with rough surface due to chemical disintegration showed weathering rinds of several millimeter thick. Comparision between inner fresh and outer altered zones did not show notable change in clay mineralogy except dissolution of calcite and some plagioclase. Most significant weathering was observed in the biotite flakes, eolian volcanic glass, sulfides, and carbonates in the debris. Biotite flakes derived from granodiorite were altered to hydrobiotite and vermiculite of yellow brown color. Minor epitactic kaolinite and gibbsite were formed in the cleaved flakes of weathered biotite. Pyrite was replaced by iron oxides. Calcite was congruently dissolved. Volcanic glass of basaltic andesite composition showed alteration rim of several micrometer thick or completely dissolved leaving mesh of plagioclase laths. In the alteration rim, Si, Na, Mg, and Ca were depleted, whereas Al, Ti, and Fe were relatively enriched. Mineralization of lichen and moss debris is of much interest. They are rich of A3 and Si roughly in the ratio of 2:1 to 3:1 typical of allophane. In some case, Fe and Ti are enriched in addition to Al and Si. Transmission electron microscopy of the samples rich of volcanic glass showed abundant amorphous aluminosilicates, which are interpreted as allophane. Chemical weathering in the King George Island is dominated by the leaching of primary phyllosilicates, carbonates, eolian volcanic glass, and minor sulfides. Authigenesls of clay minerals is less active. Absence of a positive evidence of significant authigenic smectite formation suggests that its contribution to the clay mineralogy of marine sediments are doubtful even near the maritime Antarctica undergoing a more rapid and intenser chemical weathering under more humid and milder climate.

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A facile synthesis of transfer-free graphene by Ni-C co-deposition

  • An, Sehoon;Lee, Geun-Hyuk;Jang, Seong Woo;Hwang, Sehoon;Yoon, Jung Hyeon;Lim, Sang-Ho;Han, Seunghee
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.129-129
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    • 2016
  • Graphene, as a single layer of $sp^2$-bonded carbon atoms packed into a 2D honeycomb crystal lattice, has attracted much attention due to its outstanding properties. In order to synthesize high quality graphene, transition metals, such as nickel and copper, have been widely employed as catalysts, which needs transfer to desired substrates for various applications. However, the transfer steps are not only complicated but also inevitably induce defects, impurities, wrinkles, and cracks of graphene. Furthermore, the direct synthesis of graphene on dielectric surfaces has still been a premature field for practical applications. Therefore, cost effective and concise methods for transfer-free graphene are essentially required for commercialization. Here, we report a facile transfer-free graphene synthesis method through nickel and carbon co-deposited layer. In order to fabricate 100 nm thick NiC layer on the top of $SiO_2/Si$ substrates, DC reactive magnetron sputtering was performed at a gas pressure of 2 mTorr with various Ar : $CH_4$ gas flow ratio and the 200 W DC input power was applied to a Ni target at room temperature. Then, the sample was annealed under 200 sccm Ar flow and pressure of 1 Torr at $1000^{\circ}C$ for 4 min employing a rapid thermal annealing (RTA) equipment. During the RTA process, the carbon atoms diffused through the NiC layer and deposited on both sides of the NiC layer to form graphene upon cooling. The remained NiC layer was removed by using a 0.5 M $FeCl_3$ aqueous solution, and graphene was then directly obtained on $SiO_2/Si$ without any transfer process. In order to confirm the quality of resulted graphene layer, Raman spectroscopy was implemented. Raman mapping revealed that the resulted graphene was at high quality with low degree of $sp^3$-type structural defects. Additionally, sheet resistance and transmittance of the produced graphene were analyzed by a four-point probe method and UV-vis spectroscopy, respectively. This facile non-transfer process would consequently facilitate the future graphene research and industrial applications.

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Property of Composite Titanium Silicides on Amorphous and Crystalline Silicon Substrates (아몰퍼스실리콘의 결정화에 따른 복합티타늄실리사이드의 물성변화)

  • Song Oh-Sung;Kim Sang-Yeob
    • Journal of the Microelectronics and Packaging Society
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    • v.13 no.1 s.38
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    • pp.1-5
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    • 2006
  • We prepared 80 nm-thick TiSix on each 70 nm-thick amorphous silicon and polysilicon substrate using an RF sputtering with $TiSi_2$ target. TiSix composite silicide layers were stabilized by rapid thermal annealing(RTA) of $800^{\circ}C$ for 20 seconds. Line width of $0.5{\mu}m$ patterns were embodied by photolithography and dry etching process, then each additional annealing process at $750^{\circ}C\;and\;850^{\circ}C$ for 3 hours was executed. We investigated the change of sheet resistance with a four-point probe, and cross sectional microstructure with a field emission scanning electron microscope(FE-SEM) and transmission electron microscope(TEM), respectively. We observe an abrupt change of resistivity and voids at the silicide surface due to interdiffusion of silicide and composite titanium silicide in the amorphous substrates with additional $850^{\circ}C$ annealing. Our result implies that the electrical resistance of composite titanium silicide may be tunned by employing appropriate substrates and annealing condition.

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Silicidation Reaction Stability with Natural Oxides in Cobalt Nickel Composite Silicide Process (자연산화막 존재에 따른 코발트 니켈 복합실리사이드 공정의 안정성)

  • Song, Oh-Sung;Kim, Sang-Yeob;Kim, Jong-Ryul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.1
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    • pp.25-32
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    • 2007
  • We investigated the silicide reaction stability between 10 nm-Col-xNix alloy films and silicon substrates with the existence of 4 nm-thick natural oxide layers. We thermally evaporated 10 nm-Col-xNix alloy films by varying $x=0.1{\sim}0.9$ on naturally oxidized single crystal and 70 nm-thick polycrystalline silicon substrates. The films structures were annealed by rapid thermal annealing (RTA) from $600^{\circ}C$ to $1100^{\circ}C$ for 40 seconds with the purpose of silicidation. After the removal of residual metallic residue with sulfuric acid, the sheet resistance, microstructure, composition, and surface roughness were investigated using a four-point probe, a field emission scanning electron microscope, a field ion bean4 an X-ray diffractometer, and an Auger electron depth profiling spectroscope, respectively, to confirm the silicide reaction. The residual stress of silicon substrate was also analyzed using a micro-Raman spectrometer We report that the silicide reaction does not occur if natural oxides are present. Metallic oxide residues may be present on a polysilicon substrate at high silicidation temperatures. Huge residual stress is possible on a single crystal silicon substrate at high temperature, and these may result in micro-pinholes. Our results imply that the natural oxide layer removal process is of importance to ensure the successful completion of the silicide process with CoNi alloy films.

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Mineralogy and Geochemistry of Quaternary Fault Gouges in the Southeastern Korean Peninsula (한반도 동남부 제4기 단층 비지의 광물학적 및 지구화학적 연구)

  • 손승완;장태우;김영규
    • Journal of the Mineralogical Society of Korea
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    • v.15 no.2
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    • pp.85-94
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    • 2002
  • XRF, XRD, EPMA have been used to investigate microstructures and mineralogical changes caused by the faulting and fluids associated with faulting in the Quaternary fault gouge zones at the Sangchon, Ipsil and Wangsan faults located at the southeastern part of the Korean Peninsula. The chemical compositions of faulted rocks and protoliths analyzed by XRF show that the fault gouges are relatively enriched in TiO$_2$, P$_2$O$_{5}$, MgO, and Fe$_2$O$_3$) compared with protoliths, indicating that the fluids associated with faulting were highly activated. XRD results show that the fault gouges predominantly consist of quartz, feldspar, calcite and clay minerals. Clay minerals formed in the gouge zones are mainly composed of smectite characterized by a dioctahedral sheet. Based on EPMA analyses various kinds of sulfide, carbonate, phosphate minerals were identified in the gouge zones and protoliths. Xenotime of grey fault gouge of the Sangchon fault and sulfide minerals of contact andesitic rock of Ipsil fault and contact grey andesitic rock of Wangsan fault were probably formed by inflow of hydrothermal solution associated with faulting prior to the Quaternary. Carbonate minerals of contact andesitic rock and gouge zone of the Ipsil fault were formed by inflow of fluid associated with faulting prior to the Quaternary. They are heavily fractured and have reaction rim on their edge, indicating that faultings and inflow of fluids were highly activated after carbonate minerals were formed. Calcites of Wangsan fault seemed to be formed in syntectonic or posttectonic Quaternary faulting.g.