• Title/Summary/Keyword: 엑스선 형광

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Fabrication of Gd2O2S:Tb fine scintillator film and evaluation of image quality for resolution improvement of X-ray imaging based on CMOS (CMOS 기반 X선 영상의 해상력 향상을 위한 Gd2O2S:Tb 미세형광체 필름 제작 및 영상 질 평가)

  • Kang, Sang-Sik;Choi, Young-Zoon;Jung, Bong-Jae;No, Si-Cheul;Cho, Chan-Hoon;Yoon, In-Chan;Park, Ji-Koon
    • Journal of the Korean Society of Radiology
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    • v.5 no.5
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    • pp.283-287
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    • 2011
  • In this study, fine $Gd_2O_2S$:Tb powder was synthesized by using a low temperature solution-combustion method for a high-resolution digital x-ray imaging detector. From the fabricated phosphor power, the fine scintillator films was fabricated by particle sedimentation method and was investigated the luminescent property. From the experimental results of relative light output as a function of terbium concentration, the highest luminescent efficiency has at 5 wt% Tb concentration, and luminescent intensity decreased rapidly according to quenching effect about higher Tb concentration. Also, the relative light output of $270{\mu}m$-$Gd_2O_2S$:Tb film has 2945 pC/$cm^2$/mR. And light intensity was saturated at higher film thickness. Finally, to evaluate an image acquisition performance of fabricated phosphor, images were obtained by using commercial CMOS sensor and measured the MTF, NPS, and DQE. DQE(0 lp/mm) of fine phosphor film has 37%. But, DQE improvement of fine phosphor film is possible by resolving problem of film fabrication process and has a significant potential in the application of digital radiation imaging system later.

Production Techniques for Goryeo Wooden Lacquerware (고려시대 목심칠기 木芯漆器의 제작기법 연구)

  • Yi, Yonghee;Park, Suzin;Yun, Eunyoung;Jung, Hyejin
    • Conservation Science in Museum
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    • v.15
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    • pp.78-95
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    • 2014
  • To examine the materials, production techniques, and key features of Goryeo wooden lacquerwares, scientific analysis was conducted on six relevant lacquerware items. All of the items, except for a lacquered bowl duksu 4123, were found to have been made by first covering the surface of the wood with cloth and then varnishing with lacquer. The wooden frames of flower-shaped lacquered case and pine leaves shape lacquered case were made by wrapping thin wood around either the lid or bottom panel. In most cases, microscopic analysis revealed a lower layer of lacquer mixed with bone ash and bone dust, followed by an upper varnish layer of lacquer. SEM-EDS analysis and μ-XRF Micro-X-ray Fluorescence analysis showed that vermilion lacquer mixed with cinnabar was used on the surface. A lid decorated with a dot pattern was made by first varnishing the surface with yellow lacquer mixed with orpiment, and then irregular dot pattern with a mixture of black lacquer and soot. The vermilion lacquer used to varnish the side of the lacquered bowls was composed of lacquer mixed with cinnabar and minium Red Lead.

A Study of Material and Production Technique of Scroll Painting Ring in Joseon (조선시대 족자 장황에 사용된 고리의 재료 및 제작기법 연구)

  • Jang, Yeonhee;Yun, Eunyoung;Kwon, Yoonmi;Kim, Sooyeon
    • Conservation Science in Museum
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    • v.16
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    • pp.56-81
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    • 2015
  • Ring in the scroll painting is one of the mounting elements which are fixed string and tassel to hang, these differ widely in shape and produce a variety of metals. Most traditional shapes of ring have been lost, because of remount, there are used Japanese style rings in present.Therefore, this study examines to shape, production technique and analyze component traditional style rings of 19 traditional scroll paintings in National Museum of Korea for restoration of original style. Ring has been recorded official names; Wonhwan(Ring), Gukhwadong(Chrysanthemum shaped ornaments), Baemok(Ring-shaped nail) in Uigwe. Result of an optical microscope (Leica, M205A), Wonhwan has two type of production technique; one is cutting and bending a metal rod and other is cast. Baemok is made to forging process after metal rod or plate by casting alloy. Baemok decoration is metal plate cutting shape, and then decorates it with pattern by using kicking line engraving, chasing and so on. Component analysis result from portable X-ray fluorescence found various metals, such as, brass, iron silver-cooper. Brass based on copper and zinc used rings of 17 scroll painting. Baemok of Yun Sidal portrait is used iron and plated with a tin-lead alloy. Yi Seogu portrait is silver-cooper alloy in whole ring.

Experimental Study on the Proposal of an Assessment Method and Quality Standard for Identifying the Fine Particles of Clay Components in Fine Aggregates (잔골재의 토분 평가방법 및 품질기준 제안을 위한 실험적 연구)

  • Choi, Hyun-Kyu;Han, Min-Cheol
    • Journal of the Korea Institute of Building Construction
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    • v.22 no.6
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    • pp.585-596
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    • 2022
  • The purpose of this study is to propose an assessment method to analyze clay collectively referred to as fine particles of clay components contained in fine aggregates, and to propose quality standards for clay use through correlation with the performance of concrete to verify the properties of clay measured according to the method. As a result, it is analyzed that it will be suitably utilized as a method to assess the fine particles of the clay component of fine aggregates through the component analysis of XRF. Regarding the related quality standards, considering the error rate of about 10% of KCS 14 20 10, the related quality standards were analyzed to be safe when Al2O3+Fe2O3+MgO is 23.5% or less and SiO2+K2OSiO2+K22O is 66.5% or more. To build on this study, it is expected that a comprehensive review will be conducted through additional follow-up studies such as on clay of coarse aggregates and durability analysis to establish a system for quality control of the soil fraction of aggregates.