• Title/Summary/Keyword: SiO$_2$-B$_2$O$_3$

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A Basic Study on Capture and Solidification of Rare Earth Nuclide (Nd) in LiCl-KCl Eutectic Salt Using an Inorganic Composite With Li2O-Al2O3-SiO2-B2O3 System (Li2O-Al2O3-SiO2-B2O3 구조의 무기합성매질을 이용한 LiCl-KCl 공융염 내 희토류 핵종(Nd)의 분리 및 고화에 관한 기초연구)

  • Kim, Na-Young;Eun, Hee-Chul;Park, Hwan-Seo;Ahn, Do-Hee
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.15 no.1
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    • pp.83-90
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    • 2017
  • The pyroprocessing of spent nuclear fuel generates LiCl-KCl eutectic waste salt containing radioactive rare earth nuclides. It is necessary to develop a simple process for the treatment of LiCl-KCl eutectic waste in a hot-cell facility. In this study, capture and solidification of a rare earth nuclide (Nd) in LiCl-KCl eutectic salt using an inorganic composite with a $Li_2O-Al_2O_3-SiO_2-B_2O_3$ system was conducted to simplify the existing separation and solidification process of rare earth nuclides in LiCl-KCl eutectic waste salt from the pyroprocessing of spent nuclear fuel. More than 98wt% of Nd in LiCl-KCl eutectic salt was captured when the mass ratio of the composite was 0.67 over $NdCl_3$ in the eutectic salt. The content of $Nd_2O_3$ in the Nd captured-composite reached about 50wt%, and this composite was directly fabricated into a homogeneous and chemical resistant glass waste in a monolithic form. These results will be utilized in designing a process to simplify the existing separation and solidification process.

DATA and FT-IR absorption spectra of PbO-Bi2O3-B2O3-SiO2 glasses (PbO-Bi2O3-B2O3-SiO2 유리계 열시차분석과 FT-IR 흡수 스펙트럼)

  • Lee, Chan-Ku;Lee, Su-Dae
    • Journal of Korean Ophthalmic Optics Society
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    • v.8 no.1
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    • pp.17-22
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    • 2003
  • The experimental FT-IR spectra and DTA curves of the $PbO-Bi_2O_3-B_2O_3-SiO_2$ glasses have been investigated. The composition ratio dependence of glass transition temperature showed that the structure of this glass system changes at 60 mol% $Bi_2O_3$. We have observed that the FT-IR spectra of the investigated samples with high bismuth content are dominated by bands associated to the structural units of the heaviest cation, $Bi^{3+}$ and the boron atoms in the treated samples are three and four coordinated even for very high $Bi_2O_3$ content. The low intensity of these non-bridging oxygen bands, for high PbO content glasses, can be attributed to the strong network-forming roles of PbO. The glasses absorption bands exhibited a greater change in intensities on crystallization.

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A Study on the Co-firing Compatibility with Ag-thick film and Dielectric Characteristics of Low Temperature Sinterable SiO$_2$-TiO$_2$-Bi$_2$O$_3$-RO system (RO :BaO-CaO-SrO) Glass/Ceramic Dielectric Material with the Addition of B$_2$O$_3$ (저온 소성용 SiO$_2$-TiO$_2$-Bi$_2$O$_3$-RO계(RO :BaO-CaO-SrO) Glass/ceramic 유전체 재료의 B$_2$O$_3$첨가에 따른 Ag 후막과의 동시 소결시 정합성 밀 유전 특성에 관한 연구)

  • 윤장석;이인규;유찬세;이우성;강남기
    • Journal of the Microelectronics and Packaging Society
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    • v.6 no.3
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    • pp.37-43
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    • 1999
  • Co-firing incompatibility between the low temperature sinterable Glass/ceramic and Ag-thick film was studied. The dielectric material, which has been developed for microwave frequency applications, consists of $SiO_2-TiO_2-Bi_2O_3$-$Bi_2O_3$-RO system(RO:BaO -CaO-SrO) crystallizable glass and $Al_2O_3$as a ceramic filler. The large camber in the sintered specimen and cracks at the Ag-film under the influence of the camber occurred due to the difference of densification rate between the ceramic sheet and the Ag-film $B_2O_3$addition to the Glass/ceramic mixture reduced the severe camber. The cambers decreased with increasing the $B_2O_3$ content, and completely disappeared with 14 vol% $B_2O_3$addition. With additions of $B_2O_3$, $\varepsilon_{r}$ decreased abruptly, Q$\times$f value increased largely and the $\tau_f$ value of the material quickly shifted to positive one.

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A Study on Improvement of Fracture Toughness of $\beta-SiC-ZrB_2$Composites ($\beta-SiC-ZrB_2$ 복합체의 파괴인성 증진연구)

  • Shin Yong-Deok;Ju, Jin-Young;Yoon, Se-Won;Hwang, Chul;Song, Joon-Tae
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.291-294
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    • 1999
  • The effect of AI$_2$O$_3$+Y$_2$O$_3$additives on fracture toughness of $\beta$-SiC-ZrB$_2$composites by hot-pressed sintering were Investigated. The $\beta$-SiC-ZrB$_2$ ceramic composites were hot-presse sintered and annealed by adding 1, 2, 3wt% AI$_2$O$_3$+Y$_2$O$_3$(6:4wt%) powder as a liquid forming additives at 195$0^{\circ}C$ for 4h. In this microstructures, no reactions were observed between $\beta$-SiC and ZrB$_2$, and the relative density Is over 90.79% of the theoretical density and the porosity decreased with increasing AI$_2$O$_3$+Y$_2$O$_3$ contents. Owing to crack deflection and crack bridging of fracture toughness mechanism, the fracture toughness showed the highest of 5.5328MPa . m$^{1}$2/ for composites added with 2wt% AI$_2$O$_3$+Y$_2$O$_3$ additives at room temperature. But the standard deviation of fracture toughness of specimens decreased with increasing AI$_2$O$_3$+Y$_2$O$_3$ contents and showed the highest of 0.8624 for composite tilth 1wt%, AI$_2$O$_3$+Y$_2$O$_3$additives.

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Preparation of CaO-SiO2-B2O3 Glass-ceramics and Evaluation of Bioactivity Using in-vitro Test (CaO-SiO2-B2O3계 결정화 유리의 제조와 in-vitro법을 이용한 생체활성 평가)

  • Ryu, Hyun-Seung;Seo, Jun-Hyuk;Kim, Hwan;Hong, Kug-Sun;Kim, Deug-Joong;Lee, Jae-Hyup;Lee, Dong-Ho;Chang, Bong-Soon;Lee, Choon-Ki
    • Journal of the Korean Ceramic Society
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    • v.39 no.5
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    • pp.490-497
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    • 2002
  • Sintering property, mechanical property and bioactivity of $CaO-SiO_2-B_2O_3$ glass-ceramics were investigated. This glass-ceramics was sintered at 750-830${\circ}$ and showed nearly pore-free microstructure. The glass-ceramics consisted of three phases, i.e. monclinic-wollastonite, calcium borate and borosilicate glass matrix. The mechanical strength was higher than that of other bioactive ceramics, especially compressive strength(2813 MPa) and fracture toughness($3.12 MPa{\cdot}m^{1/2}$). Bioactivity of the glass-ceramics depends on amount of $CaB_2O_4$ and borosilicate glass matrix. It might be likely that more soluble $CaB_2O_4$ raises supersaturation of Ca ion in SBF solution and borosilicate glass forms Si-OH group that presents nucleation site of hydroxycarbonate apatite(HCA) layer. So, glassceramics of more $CaB_2O_4$ and borosilicate glass showed better bioactivity.

Low Firing Temperature Nano-glass for Multilayer Chip Inductors (칩인덕터용 저온소성 Nano-glass 연구)

  • An, Sung-Yong;Wi, Sung-Kwon
    • Journal of the Korean Magnetics Society
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    • v.18 no.1
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    • pp.43-47
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    • 2008
  • [ $ZnO-Bi_2O_3-Al_2O_3-B_2O_3-SiO_2$ ] nano-glass has been prepared by sol-gel method. The mean particle size was 60.3 nm with narrow size distribution. The nano-galss has been used as a sintering aid for the densification of the NiZnCu ferrites. The ferrite was sintered with nano-glass sintering aids at $840{\sim}900^{\circ}C$, 2 h and the initial permeability, quality factor, density, and saturation magnetization were also measured. The initial permeability of 0.5 wt% nano-glass added toroidal sample for NiZnCu ferrites sintered at $900^{\circ}C$ was 193.3 at 1 MHz. The initial permeability and saturation magnetization were increased with increasing annealing temperature. As a result, $ZnO-Bi_2O_3-Al_2O_3-B_2O_3-SiO_2$ nano-glass systems were found to be useful as sintering aids for multilayer chip inductors.

The Crystallization of LiO2-MgO-MgF2-SiO2 Glass System by B2O3 addition (B2O3의 첨가에 따른 저온 소결기판용 LiO2-MgO-MgF2-SiO2계 유리의 결정화에 관 한 연구)

  • 김병일
    • Journal of the Microelectronics and Packaging Society
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    • v.5 no.1
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    • pp.31-38
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    • 1998
  • 저온소결기판용 Glass-ceramics를 제조하기 위해 LiO2-MgO-MgF2-SiO2계 조성에 서 B2O3첨가가 결정화 특성 및 물성에 미치는 영향을 고찰하였다. 145$0^{\circ}C$에서용융하여 제조 한 모유리의 핵형성 온도와 결정화 온도를 결정하기 위해 TMA와 DTA분석을 실시하였다. 결정화시킨 유리의 결정상과 미세구조를 관찰하기 위하여 XRD와 SEM관찰을 실시하였다. Water swelling을 통해 Glass-ceramics powder를 제조하였으며 제조한 powder의 평균입자 크기는 8.32$\mu$m였다.

The Crystallization of $Li_2O-MgO-MgF_2-SiO_2$ Glass System by $B_2O_3$ addition (B$_2$O$_3$의 첨가에 따른 저온 소결기판용 $Li_2O-MgO-MgF_2-SiO_2$)

  • 박대현;강원호
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.11a
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    • pp.39-43
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    • 1997
  • Effects of B$_2$O$_3$ addition in the Li$_2$O-MgO-MgF$_2$-SiO$_2$g1ass system were investigated in order to make glass-ceramics for low temperature firing substrate. Base glass was made by melting at 145$0^{\circ}C$ . This glass was analyzed by THA and DTA to settle nucleation and crystallization temperature. After crystallization. crystal phase and microstructure were absorvated by XRD and SEM. Glass powders were made by water swelling method. Average particle size was 5.44${\mu}{\textrm}{m}$

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