• The Journal of the Petrological Society of Korea
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• v.13 no.3
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• pp.142-151
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• 2004

The metamorphic rocks of Yongin-Anseong area in Gyeonggi massif are composed of high-grade gneisses and schists which are considered as Precambrian basement, and Jurassic granite which intruded the metamorphic rocks. In this paper, we discuss the geochemical characteristics of metamorphic rocks and granites in this area based on REE and Nd isotope geochemistry. And we also discuss the petrogenetic relationship between metamorphic rocks and granites in this area. Most of Nd model ages (T$\_$DM/$\^$Nd/) from the metamorphic rocks range ca. 2.6Ga～2.9Ga which are correspond to the main crustal formation stage in Gyeonggi massif by Lee et. al. (2003). And Nd model ages show that the source material of quartzofeldspathic gneiss is slightly older than that of biotite banded gneiss. In chondrite-normalized rare earth element pattern, the range of (La/Yb)$\_$N/ value from biotite banded gneiss is 37～136, which shows sharp gradient and suggests that biotite banded gneiss was originated from a strongly fractionated source material. However, that of amphibolite is 4.65～6.64, which shows nearly flattened pattern. Particularly, the chondrite normalized REE patterns from the high-grade metamorphic rocks show the REE geochemisoy of original source material before metamorphism. In addition, the values of (La/Yb)$\_$N/ and Nd model ages of granite are 32～40 and 1.69Ga～2.08Ga, respectively, which suggest that the source material of granite is different from that of Precambrian basement such as biotite banded gneiss and quartzofeldspthic gneiss in the area.

• Analytical Science and Technology
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• v.13 no.5
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• pp.584-591
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• 2000

The separation of Nd from the simulated $U_3Si/Al$ spent fuel solution with sequential two-step anion exchange separation has been studied. To prepare the simulated $U_3Si/Al$ spent nuclear fuel, unirradiated $U_3Si/Al$ whose composition consists of small $U_3Si$ particle dispersed in an Al matrix with Al cladding was dissolved with a mixture of 4 M HCl and 10 M $HNO_3$ and 8 or 15 fission product elements were added to the dissolved solution. The trace amount of silica in the solutions was removed by evaporating to dryness with HF and the U was adsorbed on the first anion exchange resin. Neodymium can be purely isolated from the fission product elements with a methanol-nitric acid eluent using the second anion exchange resin. A large excess of Al didn't influence on the elution velocity of Nd, but reduced the eluted contents of Nd, Al, Eu, Gd, Sm and Sr, A large amount of Al was removed first from the column with 3 mL of loading solution (0.8 M $HNO_3$/99.8% MeOH) before Nd elution by the eluent [0.04 M $HNO_3$-99.8% MeOH(1:9)]. The recovery of Nd was more than 94%, regardless of Al contents. Taking the 9 to 13 mL fraction of eluate was effective to purely isolate Nd.

• Resources Recycling
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• v.26 no.4
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• pp.79-87
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• 2017

Extraction and separation behaviors of La, Ce, Pr, Nd and Sm from light rare earth multi - component mixed solutions by Cyanex 572 were studied. As extractant concentration increased, the $pH_{50}$ values of all the five components decreased. When extractant concentration was larger than 0.6 M, the separation factor of La and Ce, Nd and Sm was higher than 10, while the separation factor between Ce and Pr, Pr and Nd was as low as 0.5~2.2. Addition of TBP to the 0.6 M Cyanex 572 had little synergistic effect on the phase separation rate and separation factor. From the analysis of experiment results, group separation of [La]/[Pr, Nd, Sm] and [Pr, Nd]/[Sm] could be possible, but in case of the group separation between [La, Ce] and [Pr, Nd] was not available because of the low separation factor between Ce and Pr.

• The Journal of Internal Korean Medicine
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• v.22 no.4
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• pp.743-747
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• 2001

Hepatic encephalopathy is caused by disorders affecting the liver. The exact cause of the disorder is unknown. It occurs changes in mental state, consciousness, behavior, personality and changes in mood include forgetfulness, confusion, disorientation, delirium, dementia, decreased alertness, daytime sleepiness, decreased responsiveness, progressive stupor, coma. As 3 admission patients into oriental hospital of daejeon university include 2 cases of cerebral infarction, 1 case of liver cirrhosis, we found those are all hepatic encephalopathy. But until the diagnosis is made, we have many mistakes to find correct. Among the mistackes, specialy mixed thing is to compare hepatic encephalopathy and cerebral infarction. So, we report these cases with a brief review of related literatures.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.6
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• pp.432-439
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• 2012

Purpose: The aim of this study was to investigate the blood supply to the maxillary sinus in Koreans using computed tomography of the lateral wall of the sinus, and to analyze the data according to demographic data, and to compare our results with previously published research. Methods: One hundred and three patients (males 51, females 52) who visited the dental clinic were evaluated. We investigated the canals with cone-beam computed tomography, and measured the diameter and length from the bony notch of the vascular canal at the lateral wall of the sinus to each of the reference planes. Results: Most types of vascular canal were type I & II (total 72.2%) which were driving through inside the sinus wall. Type IV, V were frequently investigated in 1st premolar and 2nd molar. Mean height; from anterior nasal spine-posterior nasal spine plane to vascular canal was 5.56 mm in 1st premolar, 2.11 mm in 2nd premolar, 0.98 mm in 1st molar, 4.32 mm in 2nd molar; from the basal layer of the sinus was 4.93 mm in 1st premolar, 5.00 mm in 2nd premolar, 6.05 mm in 1st molar, 7.91 mm in 2nd molar; and from alveolar crest, 20.80 mm in 1st premolar, 16.57 mm in 2nd premolar, 14.01 mm in 1st molar, 16.17 mm in 2nd molar. The mean height of the vascular canal of each reference plane showed no significant difference between sex, site (left or right) and age. The mean diameters of the canals were 1.76 mm in male, and 1.50 mm in female. Diameter decreased with age, and tooth site (from 1st premolar to 2nd molar). Conclusion: These results show that the mean diameter of the vascular canal of the maxillary sinus varies according to age, sex, and tooth site, but that the mean height of canal had no significant difference based on these three factors.

• Resources Recycling
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• v.22 no.4
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• pp.55-61
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• 2013

In this study, eco efficiency analysis is performed to analyze Neodymium (Nd) containing permanent magnet recycling process. Life cycle assessment (LCA) and life cycle costing (LCC) are used to apply eco efficiency analysis. In the environmental aspects, global warming potential (GWP) of 1kg permanent magnet is 1.25E + 00 kg $CO_2$ eq. and abiotic resource depletion potential (ADP) is 1.10E - 02 Sb eq. This recycling process costs about 2130 KWR. Environmental efficiency of GWP is at 6.43 and ADP is at 5.32 when compared with vigin metal. Economic efficiency is at 6.74. This study confirms that Nd containing permanent magnet recycling process is sustainable system because of environmental and economical improvement.

• Journal of Society of Preventive Korean Medicine
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• v.3 no.1
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• pp.125-145
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• 1999

The effects of Wang-ttum, Magnetic Water, Magnetic field and Sibjeondaebotang on hemodynamics in sleep deprivation were studied. The results as follows; 1. In case of Wang-ttum operated group, significant changes were observed at 12 p.m., 2 a.m., 4 a.m. in maximum blood pressure for the first and second overnight stay and at 2 a.m. for the third and, respectively, average blood pressure at 12 p.m., 2 a.m. for the 1st and 2nd overnight stay, minimum blood pressure at 10 p.m.. 12 p.m.. 2 a.m. for the 1st overnight stay and at 10 p.m., 12 p.m. for the 2nd and at 12 p.m. for the 3rd, pulse rate at 12 p.m., 2 a.m., 4 a.m., 6 a.m., for 1st and 2nd and at 2 a.m., 4 a.m. for the 3rd and 4th, TP-KS at 12 p.m., 2 a.m., 4 a.m., 6 a.m. for the 1st and 2nd and at 2 a.m., 4 a.m., 6 a.m. for the 3rd, PRP at 10 p.m., 12 p.m., 2 a.m., 4 a.m., 6 a.m. for the 1st and 2nd and at 12 p.m., 2 a.m., 4 a.m. for the 3rd and at 2 a.m., 4 a.m. for the 4th, TPR at 10 p.m., 12 p.m., 2 a.m., 4 a.m., 6 a.m. from 1st to 4th overnight stay. 2. In case of taking magnetic water group, significant changes were observed at 2 a.m., 4 a.m. in pulse rate for the 1st overnight stay and, respectively, PRP at 2 a.m. for the 1st, TRP at 10 p.m., 12 p.m., 2 a.m., 4 a.m., 6 a.m. for the 1st and 4th. 3. In case of attaching magnet group, TPR was significantly observed at 10 p.m. for the 1st overnight stay. 4. In case of medicating Sibjeondaebotang group, significant changes were observed at 10 p.m., 12 p.m., 2 a.m., 4 a.m., 6 a.m. in maximum blood pressure for the 1st and 2nd overnight stay and at 12 p.m., 2 a.m., 4 a.m., 6 a.m. for the 3rd and at 2 a.m., 4 a.m., 6 a.m. for the 4th and, respectively, average blood pressure at 10 p.m., 12 p.m. for the 1st and 2nd and at 10 p.m. for the 3rd and 4th, minimum blood pressure at 10 p.m., 12 p.m. from 1st to 4th, pulse rate at 2 a.m., 4 a.m., 6 a.m. from 1st to 3rd and at 2 a.m., 4 a.m. for the 4th, TP-KS at 10 p.m., 12 p.m., 2 a.m., 4a.m., 6 a.m. for the 1st and at 10 p.m., 2 a.m., 4 a.m., 6 a.m. for the 2nd and at 2 a.m., 4 a.m., 6 a.m. for the 3rd and at 6 a.m. for the 4th, PRP at 12 p.m., 2 a.m., 4 a.m., 6 a.m. for the 1st and at 10 p.m., 12 p.m., 2 a.m., 4 a.m., 6 a.m. for the 2nd and 3rd and at 12 p.m., 2 a.m., 4 a.m., 6 a.m. for the 4th, TPR at 10 p.m., 12 p.m., 2 a.m., 4 a.m., 6 a.m. from 1st to 4th. As mentioned obove, the effects of Wangttum and Sibjeondaebotang on hemodynamics in sleep deprivation were observed both the impulse of SIM-YANG and mutual function of QI-HYOL. The effects of Magnetic water and Magnetic field were observed the side of mutual function of QI-HYOL.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.1
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• pp.17-28
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• 2019

6LoWPAN based on IEEE 802.15.4 is a realistic standard platform for various Internet of Things (IoT) applications. To bootstrap the LoWPAN (Low-power Wireless Personal Area Network), each device must perform 6LoWPAN-ND address registration to assign a unique IPv6 address. Without adequate security mechanisms, 6LoWPAN-ND is vulnerable to a variety of security attacks including corrupted node attacks. Several security mechanisms have been proposed as a supplement to the vulnerability, but the vulnerability exists because it relies solely on IEEE 802.15.4 hop-by-hop security. In this paper, we propose and analyze a vulnerability of 6LoWPAN-ND address registration and a new security mechanism suitable for preventing the attack of damaged node. It also shows that the proposed security mechanism is compatible with the Internet Engineering Task Force (IETF) standard and is more efficient than the mechanism proposed in the IETF 6 lo WG.

• Journal of the Korean Magnetics Society
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• v.25 no.4
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• pp.111-116
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• 2015

Practical difficulty in the HDDR (hydrogenation - disproportionation - desorption - recombination) processing of Nd-Fe-B-type alloy is a poor reproducibility of coercivity of the HDDR-treated material. In an attempt to improve the reproducibility of coercivity of the HDDR-treated $Nd_{12.5}Fe_{80.6}B_{6.4}Ga_{0.3}Nb_{0.2}$ alloy, the hydrogen decrepitation was carefully controlled so as to induce more extensive micro-cracks in the particle. Prior to the hydrogenation and disproportionation reaction of HDDR processing, an additional hydrogen degassing was carried out at an elevated temperature of $600^{\circ}C$ under vacuum for the previously hydrogen decrepitated particle. During the additional hydrogen degassing the lattice of hydrogen absorbed $Nd_2Fe_{14}B$ phase was further shrunken, hence more microcracks were introduced in the particle due to its brittle nature. Particles with more micro-cracks had more homogeneous hydrogen absorption and desorption reaction during the HDDR-treatment. The improved reproducibility of coercivity of the HDDR-treated material was attributed to the improved homogeneity of the HDDR reactions due to the presence of more micro-cracks.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.3
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• pp.206-213
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• 2000

The microstructure and electrical properties of Pr$_{6}$/O sub 11/-Based ZnO varistors with Nd$_2$O$_3$ was doped in the range of 0.0 to 2.0 mol% were investigated. Most of the added Nd$_2$O$_3$were segregated at the nodal points and grain boundaries and were found to form the Nd-rich phase. In addition the bulk intergranular layer at the grain boundaries and nodal points was consisted of Nd-rich phase and Pr-rich phase. the average grain size was decreased in the range of 7.8 to 5.6${\mu}{\textrm}{m}$ with increasing Nd$_{2}$/O sub 3/ additive content. The nonlinearity of ZnO varistors sintered at 130$0^{\circ}C$ was much more excellent than that at 135$0^{\circ}C$ ZnO varistors doped with 1.0mol% Nd$_{2}$/O sub 3/ exhibited the best nonlinearity. which is 65.2 in the nonlinear exponent and 4.5$\mu$A in the leakage current. Consequently. it is estimated that Pr$_{6}$/O sub 11/ -based ZnO varistors doped with 1.0 mol% Nd$_{2}$/O sub 3/ are to be sufficiently used as basic composition to fabricate good varistors in the future.ure.