• Title/Summary/Keyword: ceramic pellet

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Preparation and Dielectrics Properties of Ceramic-polymer Composite Materials (세라믹-폴리머 복합체 제조 및 유전 특성)

  • Park, Myoung-Sung;Myoung, Seong-Jae;Chun, Myoung-Pyo;Jo, Jung-Ho;Nam, Joong-Hee;Kim, Byung-Ik;Nahm, Sahn
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.182-183
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    • 2008
  • 본 연구에서는 유전 손실이 낮고, 고분자(LCP)의 유전율을 높이기 위하여 (100-x)LCP(polymer)-xNPO(ceramic) 복합체 (x= 0, 10, 20, 30, 40, 50)의 유전 특성 및 미세구조를 연구하였다. LCP와 ceramic filler(NPO)는 Brabender Mixer를 사용하여 $300^{\circ}C$에서 혼합한 후, Hot press 사용하여 $300^{\circ}C$, 7ton 성형 압력으로 pellet 형태 $(2.5cm\times2.5cm\times0.1cm)$로 제조 하였다. LCP-NPO 복합 소재를 SEM을 통해 미세구조를 관찰하였고, 복합체의 유전 특성을 조사하였다.

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Wetting Behavior of Molten Salt on the Ceramic Filter Separators for Thermal Batteries (열전지용 세라믹 필터 분리판내 용융염의 젖음 거동)

  • Cho, Kwang-Youn;Riu, Doh-Hyung;Huh, Seung-Hun;Shin, Dong-Geun;Kim, Hyoun-Ee;Choi, Jong-Hwa;Cheong, Hae-Won
    • Journal of the Korean Ceramic Society
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    • v.45 no.7
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    • pp.423-429
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    • 2008
  • Ceramic Fiber separator is the promising material for thermal battery system because it reduces the production cost and offers the potential to a new application compared to a pellet type electrolyte. The molten salt electrolytes for thermal battery were prepared by the impregnation of the commercial glass filters such as GF-A, C and F (Whatman, USA) with two types of molten-lithium salts, LiCl-KCl and LiK-LiBr-LiF. The wetting properties were evaluated by wetting balance test and wetting angle measurement. The wetting behaviors were strongly affected by the composition of the molten salts and the pore structure of the glass separators. The optimum wetting conditions for maximum loading and effective retention of the molten electrolyte were also studied.

Thermodynamic Evaluations of Cesium Capturing Reaction in Ceramic Microcell UO2 Pellet for Accident-tolerant Fuel (사고저항성 핵연료용 세라믹 미소셀 UO2 소결체의 Cs 포집반응에 대한 열역학적 평가)

  • Jeon, Sang-Chae;Kim, Keon Sik;Kim, Dong-Joo;Kim, Dong Seok;Kim, Jong Hun;Yoon, Jihae;Yang, Jae Ho
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.17 no.1
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    • pp.37-46
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    • 2019
  • As candidates for accident-tolerant fuels, ceramic microcell fuels, which are distinguished by their peculiar microstructures, are being developed; these fuels have $UO_2$ grains surrounded by cell walls. They contribute to nuclear fuel safety by retention of fission products within the $UO_2$ pellet, reducing rod pressure and incidence of SCC failure. Cesium, a hazardous fission product in terms of amount and radioactivity, can be captured by chemical reactions with ceramic cell materials. The capture-ability of cesium therefore depends on the thermodynamics of the capturing reaction. Conversely, compositional design of cell materials should be based on thermodynamic predictions. This study proposes thermodynamic calculations to evaluate the cesium capture-ability of three ceramic microcell compositions: Si-Ti-O, Si-Cr-O and Si-Al-O. Prior to the calculations, the chemical and physical states of the cesium and the cell materials were defined. Then, the reactivity was evaluated by calculating the cesium potential (${\Delta}G_{Cs}$) and oxygen potential (${\Delta}G_{O_2}$) under simulated LWR circumstances of normal operation. Based on the results, cesium capture is expected to be spontaneous in all cell compositions, providing a basis for the compositional design of ceramic microcell fuels as well as a facile way for evaluating cesium capture.

Effects of Koryo Hand Therapy(KHT) on Woman Elders' Knee Pain (고려수지요법이 여성노인의 무릎통증에 미치는 효과)

  • Koh, Hyo-Jung;Jung, Mi-Kyung;Kwon, Yun-Hee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.9
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    • pp.4022-4029
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    • 2011
  • The study was done to identify the effects of Koryo Hand Therapy(KHT) of woman elders' knee pain. This is an quasi-experiment with nonequivalent control group pre- & post-test design. The subjects consisted of 105 woman elders were admitted to in elders' hospital in D city. They are randomized 35 for the experimental group A by using ceramic Seo Am pellet therapy, 35 for the experimental group B by using Seo Am moxa therapy and 35 for the control group. The Koryo Hand Therapy(KHT) was conducted 3 times per week for 6 weeks. Data analyzed using ${\chi}^2$-test, One-way ANOVA and repeated measure ANOVA with SPSS Win 17.0 version. The results of this study was knee pain of the experimental group A provided with ceramic Seo Am pellet therapy(p=.000), the experimental group B provided with Seo Am moxa therapy(p=.000) would be lower than that the control group. Knee pain of the experimental group B provided with Seo Am moxa therapy would be lower than that the experimental group A provided with ceramic Seo Am pellet therapy(p=.001). Koryo Hand Therapy(KHT) was to be effective in relieving knee pain woman elders' and it is suggested that the therapy should be used for managing.

Reaction Behavior of Ceramic Mat with Lithium Salt for the Electrolyte Separators of Thermal Batteries (전해질 분리판용 세라믹 부직포와 리튬염간의 반응성)

  • Cho, Kwang-Youn;Riu, Doh-Hyung;Shin, Dong-Geun;Lim, Kyoung-Hoon;Jin, Eun-Ju;Kim, Hyoun-Ee;Ha, Sang-Hyeon;Choi, Jong-Hwa
    • Journal of the Korean Ceramic Society
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    • v.46 no.6
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    • pp.587-591
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    • 2009
  • Lithium salt have been used mainly as electrolyte of thermal battery for electricity storage. Recently, The 3phase lithium salt(LiCl-LiF-LiBr) is tried to use as electrolyte of thermal battery for high electric power. It is reported that LiCl-LiF-LiBr salt have high ion mobility due to its high lithium ion concentration. Solid lithium salt is melt to liquid state at above $500{^{\circ}C}$. The lithium ion is easily reacted with support materials. Because the melted lithium ion has small ion size and high ion mobility. For the increasing mechanical strength of electrolyte pellet, the research was started to apply ceramic filter to support of electrolyte. In this study, authors used SiOC web and glass fiber filter as ceramic mat for support of electrolyte and impregnated LiCl-LiF-LiBr salt into ceramic mat at above $500{^{\circ}C}$. The fabricated electrolyte using ceramic mat was washed with distilled water for removing lithium salt on ceramic mat. The washed ceramic mat was observed for lithium ion reaction behavior with XRD, SEM-EDS and so on.

Electrical properties of Indium Zinc Tin tummy Transparent Conducting Oxide which doped impurities (Indium Zinc Tin turnary Transparent Conducting Oxide에서의 dopant 첨가에 따른 전기적 특성)

  • Seo, Han;Park, Jung-Ho;Choi, Byung-Hyun;Jy, Mi-Jung;Kim, Sea-Gee;Ju, Byeong-Kwon;Hong, Sung-Pyo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.183-183
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    • 2009
  • 본 연구에선 ITO에 사용되는 Indium의 양을 줄이기 위해 ITO와 유사한 성질을 보이는 조성인 Indium - Zinc - Tin Turnary compound를 연구하였다. 각 조성은 Indium - Zinc - Tin Turnary compound를 기본으로 하여 Zinc site에 이종원소인 Al2O3와 Ga2O3를 doping함에 따라 변화되는 전기적 특성을 살며보았다. 분석에 사용한 Ceramic pellet은 일반적인 Ceramic process를 거쳐 제작되었다. 각 조성의 전기적 특성은 TCR meter와 Hall effect analyser를 이용하여 측정하였고, X-ray diffraction measurements(XRD), Scanning Electron microscope(SEM)를 이용하여 결정학적 특성을 분석하였다.

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Powder Characteristics by Change of Reacting Material in Nuclear Fuel Powder Preparation (핵연료분말 제조에서 반응물질의 변화가 분말의 특성에 미치는 영향)

  • 정경채;박진호;황성태
    • Journal of the Korean Ceramic Society
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    • v.33 no.6
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    • pp.631-636
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    • 1996
  • The powder characteristics of UO2 via AUC prepared by precipitation from a UN with AC soiution produced from nuclear fuel powder conversion plant and that of the existing facility were compared. Mean particle size of AUC powder was decreased and agglomerates were much occured in case of using the AC solution that that of the gases but other properties such as particle size distribution and shape of particle are thought to be similarly. In compaction of UO2 powder the breaking pressur of agglomerated UO2 powder and the sintered density of final UO2 pellet from AC solution were measured 1.45$\times$108 N/m2 and 10.52 g/cc, These values could be used in nuclear fuel powder fabrication process.

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Synthesis of Yttrium Iron Garnet Powder by Homogeneous Precipitation and its Crystallization (균일침전법에 의한 Yttrium Iron Garnet 분말의 합성 및 결정화)

  • 안영수;한문희;김종오
    • Journal of the Korean Ceramic Society
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    • v.33 no.6
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    • pp.693-699
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    • 1996
  • YIG precursor powder was obtained by homogeneous precipitation in chloride salt solution by thermal decom-position of urea. It was found that ferric ions precipitated prior to yttrium ions. The precipitate was minute and spherical in shape. The precipitate formed consisted of the mixture of amorphous and ferric oxyhydroxide. Crystallization of YIG was proceeded by solid state reaction of intermediate YFeO3 and Fe2O3 in the temperature range of 85$0^{\circ}C$ to 140$0^{\circ}C$. Single phase of YIG was obtained by heat-treatment of the powder at 140$0^{\circ}C$ for 6 hrs in air. The powder calcined was molded into pellets and sintered in air. The maximum density of 4,92 g/cm3(95.1% of theoretical density) was obtainable for the pellet sintered at 145$0^{\circ}C$ using the powder calcined at 90$0^{\circ}C$.

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