• Nuclear Engineering and Technology
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• v.13 no.4
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• pp.254-263
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• 1981

Paper electrophoretic separation of fission products has been carried out by using the specially designed migration apparatus. In general, the isolation of rubidium, strontium, zirconium, ruthenium, cesium, cerium, molybdenum, and some short-lived fission products is more efficient under 0.1M HCl electrolyte as compared with 0.1M NaOH electrolyte. In addition to Np-239, 1-131∼135 were, in particular, observed with different iodine chemical species obtained by the paper-electrophoretic separation of short, neutron-irradiated uranyl nitrate solution.

• Korean Journal of Crystallography
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• v.12 no.1
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• pp.20-24
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• 2001

NiZn-ferrite was synthesized usign waste iron oxide catalysts which were produced from styrene monomer process and buried underground as an industrial wastes. The spinel type ferrite was obtained by calcination and sintering of the mixture of finely ground waste catalysts, nickel oxide and zinc oxide powders. The sintered body of Ni/sub 0.5/Zn/sub 0.5/Fe₂O₄ composition at 1230℃ for 5 hours showed the density of 5.38g/㎤, and initial permeability of 59 at 1 kHz. Not only cerium oxide, which existed as a major component in the catalyst, but also unicorporated NiO and ZnO into spinel structure remained as second phases after sintering.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.591-593
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• 2008

In this report, cerium doped lutetium aluminate ($Lu_3Al_5O_{12}$:Ce) phosphor has been synthesized by the solid state method under reduction atmosphere with mixture gas. The prepared phosphor shows a main luminescent peak at 555nm. Consequently, this phosphor is possible to be applicable to white LED lamp by InGaN chips.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.11a
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• pp.309-314
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• 1996

Feasibility study has been accomplished to evaluate the effectiveness of the in-vessel core debris cooling through lower cavity flooding using two dimensional finite difference scheme. The volume of cerium pool and decay power rate generated in corium pool were evaluated as important parameters to the temperature distribution on the reactor vessel lower head through previous works. In this study, the corium volume based on the System 80＋ core structure and time dependent decay power rate are considered for feasibility evaluation. In addition, preliminary plans for the in-vessel core debris cooling through lower cavity flooding as severe accident management strategy, i.e. flooding timing, method and capacity, are suggested based on the result of the numerical study, international tendency related to in-vessel core debris cooling through lower cavity flooding.

• Journal of the Korean Ceramic Society
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• v.40 no.7
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• pp.615-619
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• 2003

Temperature and frequency dependence of dielectric and electrical properties was investigated in cerium and manganese doped Sr$\_$0.6/Ba$\_$0.4/Nb$_2$O$\_$6/(60SBN) ceramic system. Structural deformation of 60SBN by dopants did not appeared. 1350$^{\circ}C$-10 h sintered specimen had higher densification than 1250$^{\circ}C$-10 h sintered one, to which dielectric properties are related. That the feature of dielectric maxima peaks was typical Diffusive Phase Transition (DPT), it was explained by "random-field Ising model". Even though 60SBN has large dielectric loss at high frequency above 100 ㎑, it is desirable for optical applications because of low dielectric loss at low frequency. From Arrhenius plot of temperature, the activation energy was calculated to 0.45-0.49 eV.

• Journal of Korea Foundry Society
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• v.25 no.2
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• pp.102-108
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• 2005

The ability and fading behavior of inoculant in ductile cast iron melt and the effect of minor element on them were investigated. The result obtanied on nodularization and the performance of inoculant were more distinct when the melt was treated and held at the high temperature range of $1450{\sim}1500^{\circ}C$ than at the lower one of $1350{\sim}1400^{\circ}C$. The performance of 5.2%Mg-Fe-Si alloy was the best of 4 nodularizers. That of Fe-75%Si(I) alloy was better than other 4 inoculants. The performance of the Fe-75%Si(I) inoculant was deteoriated by the addition of sulfur or bismuth. On the other hand, that was improved by the addition of cerium, even though its extent was not big.

• Journal of the Korean institute of surface engineering
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• v.49 no.5
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• pp.395-400
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• 2016

This article reports improved corrosion resistance and adhesion of electro-paint (E-paint) with fluoride conversion coating (FCC) on AZ31 Mg alloy for the first time. These improvements were observed in comparison to chemically polished samples with no chemical conversion coating and samples with cerium conversion coatings (CeCC). FCCs were prepared in a hydrofluoric acid (HF) solution for four different times; 10, 30, 60, and 120 s. The colour of the samples changed from light gold to brown with increasing immersion time, indicating the formation of thicker FCC coatings with increasing immersion time. The adhesion of the E-paint on FCC-coated AZ31 Mg alloy was tested after 500 h of immersion in deionized (DI) water. Salt spray test (SST) results revealed delamination of E-paint on the chemically polished sample, severe blistering on the samples with CeCC, but no delamination and no blistering on the samples with FCC.

• Nuclear Engineering and Technology
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• v.52 no.11
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• pp.2572-2580
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• 2020

Emerging gamma ray detection applications that utilize neutron-based interrogation result in the prompt emission of high-energy (>2 MeV) gamma-rays. Rapid imaging is enabled by scintillators that possess high density, high atomic number, and excellent energy resolution. In this paper, we evaluate the bright (50,000 photons/MeV) oxide scintillator, cerium-doped Gd₂Al₂Ga₃O₁₂ (GAGG(Ce)). A silicon photomultiplier (SiPM) array is coupled to a GAGG(Ce) scintillator array (12 × 12 pixels) and integrated into a coded-aperture based gamma-ray imaging system. A resistor-based symmetric charge division circuit was used reduce the multiplicity of the analog outputs from 144 to 4. The developed system exhibits 9.1%, 8.3%, and 8.0% FWHM energy resolutions at 511 keV, 662 keV, and 1173.2 keV, respectively. In addition, a pixel-identification resolution of 602 ㎛ FWHM was obtained from the GAGG(Ce) scintillator array.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05a
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• pp.824-829
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• 1998

미국의 개량형 원자력 발전소 개념설계단계에서 중대사고시 사고완화를 위한 전략으로 원자로 압력용기 외부냉각 개념이 제안되었다. 중대사고 진행과정에서 노심용융물이 원자로 압력용기 하부헤드로 재배치 되었을 때 압력용기 외벽을 냉각함으로서 노심용융물을 압력용기 내부에 가두어 두어 격납건물 내로의 유출을 방지하는 방식이다. 이 연구에서는 원자로 압력용기 하부헤드 내의 노심용융물 거동중 자연 순환에 의한 거동을 수치적으로 모의하여 보았다. 연구결과, 정상상태의 온도 및 속도분포는 현상학적으로 적절하게 모의되나 고화와 액화의 경우에는 고유모델의 필요성이 요구되었다.

• Journal of Korea Foundry Society
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• v.6 no.2
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• pp.104-115
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• 1986

I A쪽과 II A쪽이 Al-Si 합금의 공정조직개량 처리에 효과적인 것은 잘 알려진 사실이나 Na(Sodium)과 Sr(Strontium)만 상업적으로 쓰여지고 있다. 그러나 휘발성과 산화하기 쉬운점때문에 Na 은 그 양을 정확하게 조절하기가 어렵고 특히 온도가 높은 경우 더욱 곤란하나 Sr 은 휘발성이나 산화성은 없으나 micro-또한 macro-porocity의 주 원인으로 보고 되고 있다. 희토류 금속 (예 : Cerium, Lanthanum,etc )도 개량처리 효과가 있다는 논문들(ref. 2, 3, 4, 5) 이 있고, 계속 연구되어 오고 있으나 그 세부사항과 효율성에 관해 정립된 바가 없다. 이런 연유로 Al-Si 합금의 생산을 위한 개량 처리제로서의 희토류 금속의 역할에 대해 구체적이고 세부적인 개량처리기구의 구명을 위해 이 연구가 이루어졌다. Al-Si 합금 356가 채택된 이유는 상업적 Al 주물의 생산을 감안해서 였다.