• Proceedings of the Mineralogical Society of Korea Conference
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• 2002.05a
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• pp.21-22
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• 2002

• Proceedings of the KSEEG Conference
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• 2005.04a
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• pp.35-39
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• 2005

• The Journal of the Petrological Society of Korea
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• v.19 no.3
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• pp.181-197
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• 2010

This study is for finding a geoscientific factor for clarifying the source soil of the ancient earthenware finding. The used samples were the earthenware, soil and rocks, which were collected at the Gyeongju, Gyeongsan and Haman area. The chemical and mineralogical study for the samples were carried out for understanding the change of mineralogical and chemical composition among them. The mineralogical compositions of the earthenware are different from those of the soils from the surrounding area, which suggests that the mineralogical approach for clarifying the source soil of the earthenware should be difficult. Major element compositions of the earthenware also are different from those of the surrounding soils, which suggests that the comparison of the chemical composition using the major elements might be difficult for deducing the source soil of the earthenware. However, PAAS-normalized rare earth element (REE) patterns and Nd model ages among the rock, soils and earthenware from the same sampling sites show similar characteristics one another compared to those of the major element compositions. Nd-Sr isotopic systematics among the earthenware, soils and rocks also show a close relationship. Our results suggest that REE and Nd-Sr isotope geochemistry might be more useful than the other geochemical technique in clarifying the source soils of the ancient earthenware.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.13 no.4
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• pp.263-269
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• 2015

It is necessary to investigate the electrodeposition behavior of uranium and other elements on the cathode in the electrorefining process to recover the uranium selectively from the reduced metals of the electrolytic reduction process since transuranic elements and rare earth elements is dissolved in the LiCl-KCl eutectic salt. Study on separation factors of U, Ce, Y and Nd based on U and Ce was performed to investigate the deposition behavior of the cathode with respect to the concentration of rare earth elements in LiCl-KCl eutectic salt. After electrorefining with constant current mode by using Ce metal as a sacrifice anode, the contents of U, Ce, Y and Nd in the salt phase and the deposit phase of the cathode were analyzed, and separation factors of the elements were obtained from the analyses. Securing conditions of pure uranium recovery in the elctrorefining process was investigated by considering the separation factors with respect to $UCl_3$ and $CeCl_3/UCl_3$ ratio.

• Journal of the Korean Chemical Society
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• v.31 no.1
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• pp.64-70
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• 1987

Rare earth elements including Y and Th in the monazite were separated and determined by X-ray fluorescence spectrometry. The matrix effects among the rare earth elements were simultaneously corrected by means of empirical coefficient method. The values of the coefficients were quite dependent on the number of the standards. However, the different set of coefficients led to the same results. The analytical results corrected by the present method agreed with those by the inductively coupled plasma spectrometry.

• Journal of the Korean Vacuum Society
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• v.5 no.4
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• pp.315-326
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• 1996

The electronic structures of 3d and 4d core-levels of rare-earth atoms in the insulating rare-earth (Sm, Eu, Gd, and Tb) compounds were studied with x-ray photoelectron spectroscopy(XPS). It is shown that the intrinsic satellite structure due to the hybridization disappears for chemically stable-earth trivalent heavy rare-earth insulating compounds as the hybridization between f electrons of rare-earth atoms and p electrons of anion atoms decreases due to the lanthanide contraction. Eu atoms at the surface of the stable insulating trivalent Eu compounds are found to be divalent. The satellite peak of Eu 3d core-level spectra at about 10eV higher binding energy side relative the main peak comes from the multiplet structures of $\underline{3d}4f^6$ configuration. The satellite structure appearing at about 15 eV higher binding energy side relative to the main peak in all insulating rare-earth compounds is due to an energy loss process of creating a plasmon.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.421-425
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• 2003

The reductive extraction process is an important step to refine the TRU product from the electrorefining process for the preparation of transmutation reactor fuel. In this study, it was studied on the reductive extraction between the eutectic salt and Bi metal phases. The solutes were zirconium and the rare earth elements, where zirconium was used as a surrogate for the transuranic(TRU) elements. All the experiments were performed in a glove box filled with a argon gas. Li-Bi alloy was used as a reducing agent to reduce the high chemical activity of Li. The reductive extraction characteristics were examined using ICP, XRD and EPMA analysis. The reduction reaction was equilibrated within 3 hours after the Li addition. Three eutectic salt systems were compared and Zr was successfully separated from the rare earth elements in all the three salt systems.

• Proceedings of the Korean Magnestics Society Conference
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• 2013.05a
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• pp.78-78
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• 2013

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.452-458
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• 2012

Rare earth elements fertilizer and Ca were sprayed on eight-year-old 'Fuji'/M.9 apple trees during two consecutive seasons, and fruit quality was quantified at harvest and 5-month long storing in a commercial cooling house at $4^{\circ}C$ and 80~85% RH. In the first season, single-sprayed of rare earth elements fertilizer showed appreciable accumulations of its elements (La, Pr, Gd, and Nd) in the fruit. In the following season, application of higher doses accumulated higher amount, indicating that the accumulation of rare earth elements was dose-dependent. However, rare earth elements did not affect the accumulations of Ca, Mg, and K in 'Fuji' apple fruit showed that there was no interaction between rare earth elements and these macronutrients. Double-spray of 0.2% rare earth elements increased fruit redness at harvest and had exhibited better color. Although at harvest it did not show significant effects on fruit weight, pulp firmness and titratable acidity (TA), but had pronounced effects on inhibiting fruit softness and retarded decrease of TA during storing. Furthermore, it reduced respiration rate and inhibited ethylene production during storing indicated that rare earth elements may be an alternative for prolonging the shelf life of 'Fuji'/M.9 apple fruit.

• The Journal of the Petrological Society of Korea
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• v.26 no.3
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• pp.281-295
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• 2017

We determined chemical compositions like abundance of major and trace elements, Sr and Nd isotope compositions for two tektites from the Thailand and Vietnam. Their chemical compositions are similar to each other, and seem to be similar to those of PAAS (Post Archean Australian Shale) rather than upper continental crust. In particular, primitive mantle-normalized spider diagrams and chondrite-normalized REE patterns for two tektites are the same, suggesting that they might be derived from the same source material. The $^{87}Sr/^{86}Sr$ and $^{143}Nd/^{144}Nd$ ratios from Thailand tektite are $0.718870{\pm}0.000008(2{\sigma}_m)$ and $0.512024{\pm}0.000012(2{\sigma}_m)$, respectively, and those from Vietnam are $0.717022{\pm}0.000008(2{\sigma}_m)$ and $0.511986{\pm}0.000013(2{\sigma}_m)$, respectively. The $^{87}Sr/^{86}Sr$ and $^{143}Nd/^{144}Nd$ ratios from Thailand tektite are slightly enriched than those of Vietnam tektite. $^{87}Sr/^{86}Sr$ ratios from the Vietnam and Thai tektites were plotted on the range of Australasian tektites reported previously. $^{143}Nd/^{144}Nd$ ratio of Vietnam tektite from this study was lower than the range of $^{143}Nd/^{144}Nd$ ratio from the Australasian tektite reported previously whereas that of Thai tektite was included in the range of $^{143}Nd/^{144}Nd$ ratio from the Australasian tektite. The geochemical characteristics from two tektites in this study indicate that they may be derived from the very similar source materials.