• 대한화학회지
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• 제51권4호
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• pp.339-345
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• 2007

Urea는 높은 온도(60~80 °C)의 수용액 상태에서 PtCl2, H2[PtCl6]·6H2O, H2[IrCl6] Ni(CH3CO2)2 와 반응해서 각각 (1)[PtCl2(Urea)]·2H2O, (2)(NH4)2[PtCl6], (3)(NH4)2[IrCl6]·H2O, (4)[Ni2(OH)2(NCO)2(H2O)2]의 complexes를 생성 한다. complexe 1에서 urea는 중성 bidentate 리간드로써 Pt(II)와 배위한다. complexe 2,3,4에서는 높은 온도에서 반 응하는 동안 배위 urea분자들이 분해되고 다양한 반응생성물들을 얻을 수 있다. 모든 complexes은 각각 적당한 수득률 로 dark green(1) yellow(2), pale brown (3) faint green(4)의 침전물로 분리된다. 반응생성물은 열분석, IR, 1H and 13C NMR spectra에 의해 측정 되었다. 이 complexes의 구성을 설명하는 일반적인 매카니즘이 제시되었다.

• 한국전기전자재료학회논문지
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• 제27권9호
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• pp.589-593
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• 2014

AlNO multi-layer thin films on aluminum substrates were prepared by DC reactive magnetron sputtering method. $Al_2O_3$/AlNO(LMVF)/AlNO(HMVF)/Al/substrate of 4 multi-layer has been prepared in an Ar and ($N_2+O_2$) gas mixture, and $Al_2O_3$ of top layer is anti-reflection layer on double AlNO(LMVF)/AlNO(HMVF) layers and Al metal of infrared reflection layer. In this study, the roughness and surface properties of AlNO thin films were estimated by field emission scanning electron microscopy(FE-SEM). The grain size of AlNO thin films increased with increasing sputtering power. The composition of thin films has been systematically investigated using electron probe microanalysis(EPMA). The optical properties with wavelength spectrum were recorded by UV-Vis-NIR spectrophotometry at a range of 200~1,500 nm. The absorptance of AlNO films shows the increasing trend with swelling ($N_2+O_2$) gas mixture in HMVF and LMVF deposition. The excellent optical performance showed above 98% of absorptance in visible wavelength region.

• 분석과학
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• 제7권3호
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• pp.413-419
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• 1994

생체시료 중에 함유된 베크로늄브로마이드(VeBr)를 정량하기 위해 로즈벵갈(RB)과 이온쌍착물(ion-pair complex)을 형성시켜 유기용매층으로 이행시킨 다음 형광광도법 및 형광검출기를 이용한 고속액체크로마토그래프(HPLC)법으로 정량하였다. 이 때 이온쌍착물의 최적 추출조건을 검토하기 위하여 완충액의 pH, 추출용매, 진탕시간의 영향을 실험하였다. 한편, 이온착물의 형성 및 조성은 연속변화법, 몰비법, IR, $^1H$-NMR로 확인하였으며, 또한 베크로늄브로마이드와 동시 투여될 수 있는 약물의 영향도 검토하였다.

• Journal of Oral Medicine and Pain
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• 제23권2호
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• pp.193-209
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• 1998

In identifying bodies that are severely decayed or damaged, methods using fingerprints and various biochemical tests are known to have its limits. To overcome this, forensic odontological method which is based on the analysis of the cranium, tooth and dental restoration is used to enhance the accuracey of individual identification. For this reason, I have come to analysis of the dental materials that exists between the teeth that is perceived to have been previously restored and the one adjacent to it. By analyzing the constituents of gold crown-restored, non-precious metal-restored, gold inlay-restored and amalgam -restored teeth, and adjacent teeth using EDX(energy dispersive X-ray microanalysis) which was invented to analyze very small amount of elements, the nature of the restoration could be predicted and the results obtained were as follows. 1. Some of constitute of gold alloy was extracted from residual cement of gold crown restoration, but that was not extracted from the restored tooth and the one adjacent to it. 2. Some of constituents of non-precious metal alloy was extracted both in the residual cement on the tooth with no-precious metal restoration and in the tooth with the restoration itself. However, none of its constituents were found in the tooth adjacent to it. 3. Some of constituents of gold alloy were found in the residual cement of gold inlay, but they were not found in the restored tooth and the adjacent tooth. 4. Some of constituents of amalgam alloy were found both in tooth restored with amalgam and in the adjacent tooth. From the results obtained above, it is possible to utilize the data obtained from analyizing residual dental materials in a more effective way. This data compensates for the lost data due to any harm done to the restorations prior to individual identification and further enhances the accuracy. Therefore, it could be concluded that this process of analyzing residual dental materials could be beneficial to individual identification in the area of forensic odontoldogy.

• The Korean Journal of Ceramics
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• 제2권1호
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• pp.19-24
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• 1996

The phase distribution and interface chemistry by the solid-state reaction between SiC and nickel were studied at temperatures between $550 \;and\; 1250^{\circ}C$ for 0.5-100 h. The reaction with the formation of silicides and carbon was first observed above $650^{\circ}C$. At $750^{\circ}C$, as the reaction proceeded, the initially, formed $Ni_3Si_2$ layer was converted to $Ni_2$Si. The thin nickel film reacted completely with SiC after annealing at $950^{\circ}C$ for 2 h. The thermodynamically stable $Ni_2$Si is the only obsrved silicide in the reaction zone up to $1050^{\circ}C$. The formation of $Ni_2$Si layers with carbon precipitates alternated periodically with the carbon free layers. At temperatures between $950^{\circ}C$ and $1050^{\circ}C$, the typical layer sequences in the reaction zone is determined by quantitative microanalysis to be $SiC/Ni_2$$Si+C/Ni_2$$Si/Ni_2$$Si+C/…Ni_2$Si/Ni(Si)/Ni. The mechanism of the periodic band structure formation with the carbon precipitation behaviour was discussed in terms of reaction kinetics and thermodynamic considerations. The reaction kinetics is proposed to estimate the effective reaction constant from the parabolic growth of the reaction zone.

• 대한전자공학회논문지
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• 제26권6호
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• pp.63-70
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• 1989

액체금속이온원으로 부터 발생한 AuGe 이온빔을 GaAs기판에 주입시킨 후 이 시료의 표면성분과 구조를 AES(Auger electron spectroscopy), RHEED(reflection high energy electron diffraction), SEM(scanning electron microscopy) and EPMA(electron probe microanalysis)등으로 조사하였으며 AES depth profile 실험결과를 이체충돌에 의한 Monte Carlo simulation과 비교하였다. AuGe 이온이 주입된 시료를 AES, EPMA로 측정한 결과 As의 preferential스피터링이 나타났으며 300$^{circ}$C로 열처리하면 Ga과 outdiffusion되었다. 또한 측정한 Au와 Ge의 depth profile은 이체충돌에 의한 Monte Carlo simulation의 결과와 잘 일치하였다.

• 대한치과기공학회지
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• 제27권1호
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• pp.79-88
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• 2005

This study was performed to investigate the surface properties of electrochemically oxidized pure niobium by anodic oxide and hydrothermal treatment technique. Niobium specimens of $10\times10mm$ in dimension were polished sequentially from #600, #800, #1000 emery paper. The surface pure niobium specimens were anodized in an electrolytic solution that was dissolved calcium and phosphate in water. The electrolytic voltage was set in the range of 250 V and the current density was 10 $mA/cm^2$. The specimen was hydrothermal treated in high-pressure steam at 300$^{\circ}C$ for 2 hours using an autoclave. Then, specimens were immersed in the Hanks' solution with pH 7.4 at 37$^{\circ}C$ for 30 days. The surface of specimen was characterized by scanning electron microscope(SEM), energy dispersive X-ray microanalysis(EDX), potentiostat/galvanostat test, and cytotoxicity test. The results obtained was summarized as follows; According to the result of measuring corrosion behavior at 0.9% NaCl, corrosion resistance was improved more specimens treated with anodic oxide than in hydrothermal treated ones. The multi-porous oxide layer on surface treated through anodic oxidation showed a structure that fine pores overlap one another, and the early precipitation of apatite was observed on the surface of hydrothermal treated samples. According to the result of EDX after 30 days deposition in Hanks' solution, Ca/P was 1.69 in hydrothermal treated specimens. In MTT test, specimens treated through anodic oxidation and hydrothermal treated ones showed spectrophotometer similar to that of the control group. Thus no significant difference in cytotoxicity was observed (P>0.05).

• 한국전기전자재료학회논문지
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• 제11권2호
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• pp.154-161
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• 1998

The effects of melting temperature and holding time on the critical current density($J_c$) of $YBa_2Cu_3O_x$ based superconducting bulk fabricated by MPMG process were investigated. The amount of the formed $Y_2BaCuO_5$ phases increased with the melting temperature. However, the value of critical current density was highest at 1120 $^{\circ}C$. With this proper melting temperature, the effect of holding time on the critical characteristics was also investigated. In the case of Ag addition, the volume of the formed $Y_2BaCuO_5$ phase when the amount of Ag addition was 10 wt% and 20 wt% was observed to be highest at 20 minute and 40 minute respectively. But in the specimen without Ag, volume of $Y_2BaCuO_5$ phase increased as the holding time increased. The proper melting temperature and the holding time obtained were 1120 $^{\circ}C$ and 20 minute. The long holding time was not effective for the $J_c$ improvement as well as the formation of $Y_2BaCuO_5$.

• 한국대기환경학회지
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• 제24권5호
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• pp.594-603
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• 2008

A single particle analytical technique, named low-Z particle electron probe X-ray microanalysis, was applied to characterize four samples collected at an underground shopping area connected to Dongdeamun subway station, in January and May 2006. Based on the analysis of their chemical compositions of the samples, many distinctive particle types are identified and the major chemical species are observed to be soil-derived particles, iron-containing particles. sulfates. nitrates, and carbonaceous particles. which are encountered both in coarse and fine fractions. Carbonaceous particles exist in carbon-rich and organic. Soil derived particles such as aluminosilicates, AlSi/C, $CaCO_3\;and\;SiO_2$ are more frequently encountered in spring samples than winter samples. Nitrate- and sulfate-con taming particles are more frequently encountered in winter samples, and those nitrate- and sulfate-containing particles mostly exist in the chemical forms of $Ca(CO_3,\;NO_3),\;Ca(NO_3,\;SO_4),\;(Na,\;Mg)NO_3\;and\;(Mg,\;Na)(NO_3,\;SO_4)$. Fe-containing particles which came from nearby subway platform are in the range of about 10% relative abundances for all the samples. It is observed that nitrate- and sulfate-containing particles and carbonaceous particles are much more frequently encountered in indoor aerosol samples than in outdoor aerosols, implying that $NO_x,\;SO_x$, and VOCs at the underground shopping area were more partitioned into aerosol phase.

• Environmental Analysis Health and Toxicology
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• 제5권3_4호
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• pp.29-36
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• 1990

Aflatoxins, produced by strains of Aspergillus flavus and Aspergillus parasiticus, can be found worldwide in corn, barley, peanuts, and other commodities. Among this group of toxins, aflatoxin B$_1$was realized to be one of the most potent environmental carcinogens, mutagens and teratogens. It is routinely monitored by methods such as thin layer chromatography, liquid chromatography, fluorodensitometric technique and radioimmunoassay. However, these assays are expensive, necessitate radioactive reagents, and require overnight incubation. In this study, the determination of fungal flora in several sorts cereals has been carried out in order to obtain an appropriate information of the population of fungi. The quantitative analysis of aflatoxin B$_1$has been carried out by High Performance Liquid Chromatography (HPLC) method and Enzyme Linked Immunosorbent Assay (ELISA). The results were summarized as follow: 1) From the 100 samples,313 colonies of fungi were isolated. Among the 313 colonies, 274 were possible to identify into 11 genera. The identified genera were Aspergillus Penicillium, Mucor, Rhizopus, Alternaria, Cladosorium, Fusarium, Circinella, Chrysosporium, Paecilomyces and Phoma. 2) Six of Aspergillus flavus were aflatoxin-producing strains. Aspergillus flavus isolated from sample barleys was contained the highest content (21.8 $\mu\textrm{g}$/ml) of aflatoxin B$_1$. 3) The yield of aflatoxin B$_1$-oxime compound was appromately 75%. Aflatoxin B$_1$-oxime-Human serum albumin was approved by formal consent as complete antigen. 4) Direct competitive ELISA permitted detection of 0.15 ng levels. In the quantitative microanalysis, ELISA was superior to HPLC method.