• Journal of the Korean Chemical Society
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• v.39 no.3
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• pp.198-203
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• 1995

The Mo(V) $di-\mu-oxo$ type $(Mo_2O_4(H_2O)_2L)$ complexes $(L:\;C_3H_7CH(SCH_2COOH)_2,\;C_6H_5CH(SCH_2COOH)_2,\;CH_3OC_6H_4CH(SCH_2COOH)_2,\;C_5H_{10}C(SCH_2COOH)_2,\;C_3H_7C(CH_3)(SCH_2COOH)_2,\;C_3H_7CH(SCH_2CH_2COOH)_2,\;C_6H_5CH(SCH_2CH_2COOH)_2)$ have been prepared by the reaction of $[Mo_2O_4(H_2O)_6]^{2+}$ with a series of dithiodicarboxy ligands. These complexes are completed by two terminal oxygens arranged trans to one another and each ligand forms a chelate type between two molybdenum. In $Mo_2O_4(H_2O)_2L$, two $H_2O$ coordinated at trans site of terminal oxygens. The prepared complexes have been characterized by elemental analysis, infrared spectra, electronic spectra, and nuclear magnetic resonance spectra. In the potential range -0.00 V to -1.00 V at a scan rate of 20 $mVs^{-1}$, a cathodic peak at -0.50∼-0.58 V (vs. SCE) and an anodic peak at -0.40∼-0.43 V (vs. SCE) have been observed in aquous solution. The ratio of the cathodic to anodic current ($I_{pc}/I_{pa}$) is almost 1, we infer that redox is reversible reaction.

• Korean Journal of Human Ecology
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• v.9 no.3
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• pp.69-79
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• 2006

The previous studies on the intake of trace elements performed in Korea were only concerned about major elements like Fe, Zn or Cu. There is little data about the intake of minor elements like Mn, Se, Mo or Cr. And most of the data were obtained by calculation using Food Composition Tables or by analysis using atomic absorption spectrophotometers (AAS). The purpose of this study, therefore, was to evaluate the dietary intake of seven trace elements, Fe, Zn, Cu, Mn, Se, Mo, and Cr of Korean adult wonmen and to compare the data between analyzed using ICP-MS (or ICP-AES) and calculated by the CAN-Pro (or Food Composition Table). A total of nineteen adult women participated voluntarily in this study and collected one-tenth of the foods that they consumed for three consecutive days. Analyzed intake of Fe of the subjects was $6.94{\pm}2.18$ (calculated, $18.87{\pm}4.50$) mg/day, that of Ze was $9.35{\pm}4.95$ (calculated, $8.35{\pm}2.87mg/day$), that of Cu was $1.18{\pm}0.26\;(1.11{\pm}0.32mg/day)$, that of Mn was $3.69{\pm}0.69\;(2.83{\pm}1.68mg/day)$, that of Se was $41.93{\pm}9.28$ (calculated, $27.58{\pm}6.97{\mu}g/day$), that of Mo was $134.0{\pm}49.1{\mu}g/day$, and that of Cr was $136.5{\pm}147.9{\mu}g/day$. The analyzed Fe intake of the subjects did not meet Estimated Average Requirement (EAR) nor Recommended Intakes (RI) for Korean women aged 20-29 years old. However, the analyzed intakes of the other six elements, Zn, Cu, Mn, Se, Mo, and Cr, seemed to meet each of the respective RIs. The analyzed Fe intake was significantly lower than the calculated one, in fact by 2.72 times, however, the analyzed intakes of the other elements, Mn and Se, were significantly higher and those of Zn and Cu were similar than each of the calculated ones. The difference of the data between analyzed and calculated intakes indicates that it is necessary to set up database on trace element contents of foods of the Food Composition Table and the CAN-Pro so as to have accuracy.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.318-318
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• 2010

전기로를 이용하여 셀렌화한 $CuInSe_2$ (CIS)박막에 대해 연구한 결과를 발표하고자 한다. 화석연료의 과도한 사용으로 지구온난화의 환경문제가 대두되면서 영구적이고 무상의 태양에너지 이용에 대한 필요성이 점차 높아지고 있다. 빛에너지를 전기에너지로 변화시키기 위한 태양전지는 재료에 따라 다양하게 개발되고 있으며 그 중 가장 주목을 받고 있는 것 중의 하나가 $CuInSe_2$을 흡수층으로 하는 CIS 박막 태양전지이다. CIS 박막은 태양전지의 흡수층으로 사용되는데 직접천이형 밴드구조를 가지고 있고, 약 $10^5\;cm^{-1}$의 높은 광흡수계수를 가지고 있어 태양전지의 흡수층으로 적합한 물질로 각광받고 있다. 에너지 밴드갭이 1eV로 실리콘과 유사한 밴드갬을 가지고 있으나 이는 Ga, Al을 In 대신 치환함으로 조절할 할 수 있다. 무엇보다도 유리와 같은 저가의 기판위에 스퍼터와 같은 장치로 대면적 CIS 태양전지를 만들수 있다는 것이 산업적인면에서의 장점으로 알려져 있다. 본 연구에서는 $50mm{\times}50mm$ 넓이의 sodalime 유리판을 기판으로 하여 CIS 박막을 제조하고 연구하였다. 스퍼터를 이용하여 유리기판 위에 Mo (Molybdenum) 을 증착하고 그 위에 Cu-In막을 증착하였다. Cu-In/Mo/유리기판 시료는 전기로에 도입되어 셀렌화 처리 하였다. 전기로는 $10^{-1}$ Torr 정도의 진공을 수분간 유지하여 반응할 수 있는 공기(산소)를 제거하였다. 진공 혹은 5N의 고순도 질소를 흘려주며 열을 가하여 셀렌화를 하였다. 전기로에는 1g의 셀레늄(Se)이 Cu-In/Mo/유리기판 시료와 함께 도입되었다. Se이 Cu-In 막과 높은 반응성을 갖도록 Se과 Cu-In 시료는 그라파이드 상자에 함께 넣었고, 그라파이트 상자는 전기로에 넣어 셀렌화하였다. 셀렌화 온도는 $400^{\circ}C{\sim}500^{\circ}C$까지 변화시켜 가며 CIS 박막을 제조하였으며 그 물성도 조사하였다. 물성 조사는 사진, 현미경, SEM, EDX, XRD, Hall effects를 이용하였다. 셀렌화 온도가 $450^{\circ}C$ 이상에서는 CIS 박막의 흡착성이 낮아 CIS 박막이 Mo 표면에서 떨어짐을 알 수 있었다. 셀렌화 후 박막에 함유된 Se은 48%~49% 정도있었다. 제조된 CIS 박막시료를 SEM으로 확인한 결과 생성된 CIS/Mo 사이에 계면층이 생겼있음 알 수 있었다. 이러한 계면층은 $MoSe^2$층으로 사료되고, 셀렌화 온도가 높으면 계면층의 두께도 증가되는 경향을 보였다. 셀렌화 온도가 높아질수록 많은 양의 산소가 CIS 박막에 들어가는 것도 알 수 있었다. 학술회의에서 보다 깊은 조사결과를 발표하고자 한다.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2006.05a
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• pp.90-94
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• 2006

The waste solution discharged from the LCD manufacturing process contains acids like nitric, acetic and phosphoric acid and metal ions such as Al, Mo and other impurities. It is important to removal of impurities to tess than 1ppm in phosphoric acid to reuse as an etchant because the residual impurities even in sub-ppm concentration in semiconductor materials play a major role on the electronic properties. In this study, we have been clearly established that a mixed system of solvent extraction, diffusion dialysis and ion-exchange technique, which made individually the most of characteristics is developed to commercialize in an efficient system for recovering the high-purity phosphoric acid. By applying vacuum evaporation, the yield of the process are almost 99% removal of nitric acid and acetic acid was achieved. And by applying the solvent extraction method with tri-octyl phosphate(TOP) as an extractant, the removal of acetic and nitric acid from the acid mixture was achieved effectively at the ratio O/A=1/3 with four stages and the stripping of nitric acid from organic phase is attained at a ration of O/A=1 with six stages by distilled water. About 97% and 76% removal of Al and Mo were achieved by diffusion dialysis. Essentially complete less than 1ppm removal of Al, Mo by using ion exchange ion resin and purification of the phosphoric acid was obtain.

• ETRI Journal
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• v.24 no.4
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• pp.290-298
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• 2002

We present, for the first time, a prototype active-matrix field emission display (AMFED) in which an amorphous silicon thin-film transistor (a-Si TFT) and a molybdenum-tip field emitter array (Mo-tip FEA) were monolithically integrated on a glass substrate for a novel active-matrix cathode (AMC) plate. The fabricated AMFED showed good display images with a low-voltage scan and data signals irrespective of a high voltage for field emissions. We introduced a light shield layer of metal into our AMC to reduce the photo leakage and back channel currents of the a-Si TFT. We designed the light shield to act as a focusing grid to focus emitted electron beams from the AMC onto the corresponding anode pixel. The thin film depositions in the a-Si TFTs were performed at a high temperature of above 360°C to guarantee the vacuum packaging of the AMC and anode plates. We also developed a novel wet etching process for $n^+-doped$ a-Si etching with high etch selectivity to intrinsic a-Si and used it in the fabrication of an inverted stagger TFT with a very thin active layer. The developed a-Si TFTs performed well enough to be used as control devices for AMCs. The gate bias of the a-Si TFTs well controlled the field emission currents of the AMC plates. The AMFED with these AMC plates showed low-voltage matrix addressing, good stability and reliability of field emission, and good light emissions from the anode plate with phosphors.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.4
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• pp.35-40
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• 2002

Ultra-power-saving SBR has been fabricated by using vanadium and molybdenum with low work function. Because reverse leakage current is increased in inverse proportion to work function, we implanted argon ion on the n-Si layer for decreasing leakage current. The dose and acceleration energy of the argon implantation in the silicon was 1$\times$10$^{14}$ ion/$\textrm{cm}^2$, 40 keV, respectively. The forward voltages drop of fabricated V-SBR and Mo-SBR were 0.25 V and 0.39 V at the same forward current density of 60 A/$\textrm{cm}^2$. As a result, it was found that the reverse leakage current of the fabricated V-SBR was reduced over 20$mutextrm{A}$ by the argon implantation in comparison with the no implanted V-SBR. Also, owing to argon implantation, the inferiority of characteristic of the SBR was not detected.

• Korean Journal of Optics and Photonics
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• v.14 no.1
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• pp.38-43
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• 2003

Fabrication process of strain-induced channel waveguides in $LiNbO_3$ was developed using strain-optic effect and compressional strain due to ~1.4 $\mu\textrm{m}$ surface Mo/Pt metal film. Characterization of the channel waveguides revealed a single transverse and depth mode in both TE and TM polarizations. Measurements showed total insertion loss of 6.2 and 7.7 ㏈/cm for TM and TE polarizations. respectively. Electro-optic intensity modulators with 11 mm long electrode length and 21 $\mu\textrm{m}$ electrode gap at $\lambda$ = 1.15 ${\mu}{\textrm}{m}$have been produced in $LiNbO_3$ substrates using strain-induced channel waveguides. Modulation depth of 100% at $\pi$-radian voltage of 16.1V has been demonstrated. Also, 1$\times$2 on/off power splitters at $\lambda$ = 0.63 $\mu\textrm{m}$ have been produced using strain-induced channel waveguides. On/off voltage of $\pm$ 25V has been demonstrated.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.2
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• pp.139-147
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• 1996

Eight Philoppine forages were studied to obtain the following: 1) nutrient concentrations and digestibility, 2) distribution of the various minerals in fiber fractions through mineral analyses of neutral detergent fiber(NDF) and acid detergent fiber(ADF) residues, and 3) correlation coefficients among the factors affecting forage quality and mineral concentrations. These Philippine forages were paragrass [Brachiaria mutica (Forsk.) Stapf], stargrass (Cynodon plectostachyum Pilger), napiergrass (Pennisetum purpureum Schumach.) calopo (Calopogonium muconoides Desv.), centrocema (Centrocema pubescens Benth.), gliricidia [Gliricidia sepium (Jacq.) Walp.] leucaena [Leucaena leucocephala (Lam.) de Wit.] and sesbania [Sesbania grandiflora (L.) Poir]. Species differences(p<0.01) were observed on various nutrient fractions including mineral composition and digestibility. The cell wall(NDF) fraction, prepared by boiling in neutral detergent solution, contained the following proportions of the total mineral originally present (%): calcium (Ca), 0.7; phosphorus(P), 14.3; magnesium(Mg), 1.9; potassium(K), 3.7; copper(Cu), 16.4; zinc(Zn), 2.9; molybdenum(Mo), 9.3; cobalt(Co), 16.2; manganese(Mn), 5.6, and iron(Fe), 81.3. The ligno-cellulose(ADF) fraction, prepared by boiling in acid detergent solution, contained the following proportions of the total mineral originally present(%): Ca, 0.2; P, 4.4; Mg, 0.7; K, 2.8; Cu, 32.3; Zn, 1.1; Mo, 8.9; Co, 4.7; Mn, 5.4; and Fe, 36.8. Correlation coefficients among the factors affection forage quality and mineral concentrations were also observed. Evidently, 75 and 45% of the minerals in grasses and legumes was positively correlated to CP and IVDMD, respectively. Moreover, 55, 80 and 75% of the forage minerals was negatively correlated to NDF, ADF and ADL fraction, respetively, implying that most of the minerals reside in the non-structural cell components.

• Corrosion Science and Technology
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• v.19 no.4
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• pp.203-210
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• 2020

The corrosion behavior of super austenitic stainless steel was studied by examining the characteristics of the sigma phase formed in the steel. A range of experimental and analytical methods was employed, including potentiodynamic polarization tests, critical pitting temperature tests, transmission electron microscopy, and energy-dispersive spectroscopy. Three steel samples with different sigma phase levels were obtained by intentionally adjusting the manufacturing process. The results showed that the corrosion resistance of the samples was strongly dependent upon the size and distribution of the sigma phase precipitated in the samples. The larger the size of the sigma phase, the higher the Mo content in the sigma phase and the higher the depletion level of Mo at the interface between the matrix/sigma phase, the more samples with a coarse-sized sigma phase were susceptible to localized pitting corrosion at the interface. These results suggest that various manufacturing processes, such as welding and the post-heat treatment of the steel, should be optimized so that both the size and fraction of the sigma phase precipitated in the steel are small to improve the resistance to localized corrosion.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.11
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• pp.734-739
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• 2017

We prepared $SnS_x$ thin films on both soda-lime glass (SLG) and molybdenum(Mo)/SLG substrates by a two-step process using a Sn precursor followed by sulfur reaction in rapid thermal annealing (RTA) at different sulfurization temperatures ($Ts=200^{\circ}C$, $230^{\circ}C$, $250^{\circ}C$, and $300^{\circ}C$) and annealing times ($t_s=10min$ and 30 min). The single SnS phase was dominant for $200^{\circ}C{\leq}T_s$<$250^{\circ}C$, while an additional phase of $SnS_2$ was appeared at $T_s{\geq}250^{\circ}C$ alongside SnS. The SnS grains in all the samples showed strong growth along the preferred [040] direction. The band-gap energy ($E_g$) of the films was estimated to be 1.24 eV.