• Analytical Science and Technology
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• v.16 no.6
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• pp.450-457
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• 2003

The determination of uranium and its isotopes in spent nuclear fuels by isotope dilution mass spectrometry (IDMS) has been studied. The spent fuel samples were dissolved in 8 M $HNO_3$ or its mixture with 14 M $HNO_3-0.05M$ HF. The dissolved solutions were filterred on membrane filter with $1.2{\mu}m$ pore size. The uraniums in the spiked and unspiked sample solutions were quantitatively adsorbed by anion exchange resin, AG 1X8 and eluted with 0.1 M HCl. The contents of uranium and its isotopes ($^{234}U$, $^{235}U$, $^{236}U$ 및 $^{238}U$) in the spent fuel samples were determined by isotope dilution mass spectrometric method using $^{233}U$ as spike. The spike reference solution was standarized by reverse isotope dilution mass spectrometry (R-IDMS) using natural and depleted uranium. The results from IDMS were in average relative difference of 0.34% when compared with those by the potentiometric titration method.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1999.05a
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• pp.113-118
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• 1999

AMBIDEXTER(Advanced Molten-salt Break-even Inherently-safe Dual-mission Experimental and TEst Reactor)는 고온저압의 Th/$^{233}$ U 불화용융염을 핵연료로 사용하므로 피복관이나 독립된 냉각재 없이 핵연료 자체가 열수송 매체로서 순환하는 원자로시스템개념으로서 저농축 $^{235}$ U 고체 핵연료를 사용하는 기존의 원자력 발전시스템이 안고있는 핵확산과 안전성 등의 고유문제를 해결할 수 있는 혁신형 차세대 원자력 발전시스템이다.(중략)

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4327-4331
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• 2011

A new method in thermal ionization mass spectrometry (TIMS) was developed to correct peak tailing backgrounds in the isotope ratio measurements of uranium in ultra trace levels for higher accuracy. Two different uranium standard reference materials (U005 and U030) were used to construct databases of signal intensities at mass 234 u and mass 236 u, which correspond to the two uranium minor isotopes, and signal intensity of $^{238}U$. Correlations between peak tailing backgrounds and $^{238}U$ were obtained by least-squares regression on calculated backgrounds at mass 234 u and mass 236 u with respect to the signal intensity of $^{238}U$ followed by separation of the peak tails of the two major isotopes of uranium ($^{235}U$ and $^{238}U$), which enables us to obtain a master equation for peak tailing background correction on all kinds of samples. Verification of the correction method was carried out using U010 and IRMM-040a.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.234.3-235
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• 2003

The aim of this study is to evaluate the permeability of PEG-conjugated salmon calcitonin (sCT) across monolayers of Caco-2 cells that represent a model of the intestinal barrier. Caco-2 cells were grown to confluency on a permeable polycarbonate membrane to permit transport through it. Permeability experiments were performed with native-sCT and PEG-conjugated sCT (PEG M.W. 2000) at various concentrations (5uM, 10uM, 25uM, 50uM, 100uM) in the apical to basolateral direction. The barrier properties were assessed by detecting transport of markder molecules ($^3$H-mannitol) and by measuring transepithelial electrical resistance (TEER). (omitted)

• Journal of the Korean earth science society
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• v.29 no.7
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• pp.539-550
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• 2008

In this paper, we investigate the geochemical and isotope properties of the Jeongeup foliated granite (hereafter, the JFG) in the Jeongeup area, aiming at establishing the movement age of the Honam shear zone by U-Pb sphene geochronology. In the AMF diagram, the JFG corresponds to the calc alkalic rock series, and belongs to the magnesia region in the diagram of silica versus $FeO^{total}/(FeO^{total}+MgO)$. Additionally, in the Rb-Ba-Sr diagram, it is classified as granodiorite and anomalous granite with distinctive negative Eu-anomaly in the REE patterns. According to the silica and trace element contents, the JFG falls on the type VAG+syn-COLG, which implies that this was formed under the circumstance of compressional continental margin or volcanic arc. $^{143}Nd/^{144}Nd$ isotope ratios range from 0.511495 to 0.511783 and $T_{DM}$ are calculated to be about $1.68{\sim}2.36Ga$. U-Pb sphene ages of the JFG are $172.9{\pm}1.7Ma$ and $170.7{\pm}2.8Ma$, based on $^{238}U-^{206}Pb$ and $^{235}U-^{207}Pb$ ages, respectively. Presumably, the dextral ductile shearing in the Jeongeup area has occurred after 173 Ma.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2004.04a
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• pp.235-239
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• 2004

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2010.05a
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• pp.207-208
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• 2010

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2010.05a
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• pp.235-236
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• 2010

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2007.05a
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• pp.235-236
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• 2007

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2016.05a
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• pp.393-394
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• 2016