• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.182-182
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• 1999

The chemisorption effect of CO on the Ni/Cu(001) surface was investigated using LEED(Low Energy Electron Diffraction) and EELS(Electron Energy Loss Spectrscopy0 under the UHV conditions. after mounting the Cu(001) single crystal in the UHV chamber (base pressure 1$\times$10-10Torr), a clean surface was obtained after a few cycles of repeated Ar+ ion sputtering and annealing at about 40$0^{\circ}C$. The epitaxial thin Ni films were formed on the Cu(001) by evaporation from 99.999% Ni block. The pseudomorphic growth and the orderness of the thin Ni films were monitored by c(2$^{\circ}C$2) LEED pattern. CO adlayers on Ni epitaxial thin films were prepared by dosing pure CO has through a leak valve. After CO adsorpton at room temperature, two pairs of peaks were observed by EELS, whose relative intensities are changed as the film thickness is varied and time is elapsed. These two pair of peaks are likely related to different bonding sites (-top and bridge sites) of C-Ni as well as C-O vibration. Experimental results and qualitative interpretation of the spectra wille be discussed. The possibility of using EELS in combination with probe species (CO) to investigate the nature of thin film growth is mentioned. We will report the experimental result of O2 dosage on Ni film and interaction of CO and O2.

• Fashion & Textile Research Journal
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• v.18 no.5
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• pp.685-694
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• 2016

This study investigates the problems of fitness and motion suitability for Korean male military winter jackets (inner and outer) and provides data for new pattern development. We analyzed fitness and motion suitability by a questionnaire survey with 140 Korean male soldiers and a wearing evaluation with 7 subjects of central army male size. A survey of male soldiers indicated that the fitness and motion suitability satisfaction was over 3.0 (Likert scale) for both inner and outer jackets. There were opinions that the sleeve length was short for the inner jacket and the waist girth and hem girth was slightly large for the outer jacket. In the wearing evaluation results with subjects of central army male size, fitness of total length, sleeve length and collar height showed a score lower than 3.0 for the inner jacket and collar height on the outer jacket. The motion suitability result showed a low score (1.0-2.0) in an arm raising motion for the inner jacket and 2.0-3.0 at neck motion in the outer jacket. In conclusion, there is more dissatisfaction in inner jackets than outer jackets. For the inner jacket, sleeve is short, sleeve hem is narrow, collar height is a little high and the sleeve creeps up during arm motion. The waist girth and hem girth was slightly large and collar height was a little high for the outer jacket.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.3
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• pp.73-77
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• 2008

Purpose: This research is that prepare amorphous or crystalline ZnO thin films with pure strong UV emission on soda-lime-silica glass (SLSG) substrates by low-temperature annealing. Methods: Growth characteristic and optical properties of the amorphous or nano-crystalline ZnO thin films prepared on soda - lime - silica glass substrates by chemical solution deposition at 100, 150, 200, 250 and $300^{\circ}C$ were investigated using X-ray diffraction analysis, ultraviolet - visible - near infrared spectrophotometer, and photoluminescence. Results: The films exhibited an amorphous pattern even when finally annealed at $100^{\circ}C{\sim}200^{\circ}C$ for 60 min, while crystalline ZnO was obtained by prefiring at 250 and $300^{\circ}C$. The photoluminescence spectrum of amorphous ZnO films shows a strong NBE emission, while the visible emission is nearly quenched. Conclusions: These results indicate it should be possible to cheaply and easily fabricate ZnO-based optoelectronic devices at low temperature, below $200^{\circ}C$, in the future.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.619-619
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• 2009

Recently, silica nanostructures are widely used in various applicationary areas such as chemical sensors, biosensors, nano-fillers, markers, catalysts, and as a substrate for quantum dots etc, because of their excellent physical, chemical and optical properties. Additionally, these days, semiconductor silica and silicon with high purity is a key challenge because of their metallurgical grade silicon (MG-Si) exhibit purity of about 99% produced by an arc discharge method with high cast. Tremendous efforts are being paid towards this direction to reduce the cast of high purity silicon for generation of photovoltaic power as a solar cell. In this direction, which contains a small amount of impurities, which can be further purified by acid leaching process. In this regard, initially the low cast rice-husk was cultivated from local rice field and washed well with high purity distilled water and were treated with acid leaching process (1:10 HCl and $H_2O$) to remove the atmospheric dirt and impurity. The acid treated rice-husk was again washed with distilled water and dried in an oven at $60^{\circ}C$. The dried rice-husk was further annealed at different temperatures (620 and $900^{\circ}C$) for the formation of silica nanospheres. The confirmation of silica was observed by the X-ray diffraction pattern and X-ray photoelectron spectroscopy. The morphology of obtained nanostructures were analyzed via Field-emission scanning electron microscope(FE-SEM) and Transmission electron microscopy(TEM) and it reveals that the size of each nanosphares is about 50-60nm. Using the Inductively coupled plasma mass spectrometry(ICP-MS), Silica was analyzed for the amount of impurities.

• Reproductive and Developmental Biology
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• v.36 no.1
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• pp.55-64
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• 2012

Peroxiredoxin II (Prdx II; a typical 2-Cys Prdx) has been originally isolated from erythrocytes, and its structure and peroxidase activity have been adequately studied. Prdx II has been reported to protect a wide range of cellular environments as antioxidant enzyme, and its dysfunctions may be implicated in a variety of disease states associated with oxidative stress, including cancer and aging-associated pathologies. But, the precise mechanism is still obscure in various aspects of aging containing ovarian aging. Identification and relative quantification of the increased proteins affected by Prdx II deficiency may help identify novel signaling mechanisms that are important for oxidative stress-related diseases. To identify the increased proteins in Prdx $II^{-/-}$ mice, we performed RBC comparative proteome analysis in membrane fraction and cytosolic fractions by nano-UPLC-$MS^E$ shotgun proteomics. We found the increased 86 proteins in membrane (32 proteins) and cytosolic (54 proteins) fractions, and analyzed comparative expression pattern in healthy RBCs of Prdx $II^{+/+}$ mice, healthy RBCs of Prdx $II^{-/-}$ mice, and abnormal RBCs of Prdx $II^{-/-}$ mice. These proteins belonged to cellular functions related with RBC lifespan maintain, such as cellular morphology and assembly, cell-cell interaction, metabolism, and stress-induced signaling. Moreover, protein networks among the increased proteins were analyzed to associate with various diseases. Taken together, RBC proteome may provide clues to understand the clue about redox-imbalanced diseases.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.3
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• pp.137-145
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• 2009

As an efficient controlled release system for rhBMP-2, a functional nanoparticle-hydrogel complex, incorporated with matrix metalloproteinase(MMP) sensitive peptide cross-linker, was developed and used as a bone transplant. In vivo bone formation was evaluated by soft x-ray, histology, alkaline phosphatase(ALP) activity and mineral contents analysis, based on the rat calvarial critical size defect(8mm in diameter) model. Significantly, effective bone regeneration was achieved with the rhBMP-2 loaded MMP sensitive hyaluronic acid(HA) based hydrogel-Nanoparticles(NP) complex, as compared to only MMP HA, the MMP HA-NP without rhBMP-2, or even with the rhBMP-2. These improvements included the formation pattern of bone and functional marrow, the degree of calcium quantification, and the ALP activity. These results indicate that the MMP sensitive HA with nano-particle complex can be a promising candidate for a new bone defect replacement matrix, and an enhanced rhBMP-2 scaffold.

• Korean Chemical Engineering Research
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• v.53 no.2
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• pp.131-136
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• 2015

The nanostructural graphene/vanadium oxide (graphene/$V_2O_5$) composite with enhanced capacitance was synthesized by the electro-deposition in 0.5 M $VOSO_4$ solution. The morphology of composites was characterized using scanning electron microscopy (SEM), x-ray diffraction pattern (XRD), and x-ray photoelectron spectroscopy (XPS). The oxidation states of the electro-deposited vanadium oxide was found to be $V^{5+}$ and $V^{4+}$. The morphology of the prepared graphene/$V_2O_5$ composite exhibits a netlike nano-structure with $V_2O_5$ nanorods in about 100 nm diameter, which could lead a better contact between electrolyte an electrode. The composite with a deposition time of 4,000 s exhibits the specific capacitance of $854mF/cm^2$ at a scan rate of 20 mV/s and the capacitance retention of 53% after 1000 CV cycles.

• Korean Journal of Materials Research
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• v.28 no.7
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• pp.371-375
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• 2018

The manganese-, nickel-, and aluminum-doped cobalt ferrite powders, $Mn_{0.2}Co_{0.8}Fe_2O_4$, $Ni_{0.2}Co_{0.8}Fe_2O_4$, and $Al_{0.2}CoFe_{1.8}O_4$, are fabricated by the sol-gel method, and the crystallographic and magnetic properties of the powders are studied in comparison with those of $CoFe_2O_4$. All the ferrite powders are nano-sized and have a single spinel structure with the lattice constant increasing in $Mn_{0.2}Co_{0.8}Fe_2O_4$ but decreasing in $Ni_{0.2}Co_{0.8}Fe_2O_4$ and $Al_{0.2}CoFe_{1.8}O_4$. All the $M{\ddot{o}}ssbauer$ spectra are fitted as a superposition of two Zeeman sextets due to the tetrahedral and octahedral sites of the $Fe^{3+}$ ions. The values of the magnetic hyperfine fields of $Ni_{0.2}Co_{0.8}Fe_2O_4$ are somewhat increased in the A and B sites, while those of $Mn_{0.2}Co_{0.8}Fe_2O_4$ and $Al_{0.2}CoFe_{1.8}O_4$ are decreased. The variation of $M{\ddot{o}}ssbauer$ parameters is explained using the cation distribution equation, superexchange interaction and particle size. The hysteresis curves of the ferrite powders reveal a typical soft ferrite pattern. The variation in the values of saturation magnetization and coercivity are explained in terms of the site distributions, particle sizes and the spin magnetic moments of the doped ions.

• Korean Journal of Materials Research
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• v.11 no.9
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• pp.733-739
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• 2001

In Al-25Nb binary system, it was observed only formation of $D0_{22}$ $Al_3Nb$ intermetallic compound after 5hr milling but it was not observed formation of meta stable phase like L1$_2$ phase. In this state, $D0_{22}$ $Al_3Nb$ fabricated had nano sized grain of approximately 20nm. Ternary systems, transition metals such as Cr, Cu, Fe, Mn were added 6~12at.% as substitution of Al, showed formation of $D0_{22}$ $Al_3Nb$ like Al-25Nb binary system. In Al- l2Cu-25Nb system, it was observed that broad XRD pattern like amorphization of Al and not observed formation of $D0_{22}$ $Al_3Nb$ after 5hr milling. But there was mixed phase of a lot of amorphous Al and little $D0_{22}$ $Al_3Nb$ through TEM. In the states of unalloyed, 5~7hr milling time, those showed exothermic reaction at 35$0^{\circ}C$, which was formation of $D0_{22}$ $Al_3Nb$ like Al-25Nb binary system. With increasing milling time to 10hr, $D0_{22}$ $Al_3Nb$ was transformed to mixed phase of amorphous and nanocryatlline, having approximately 10nm grain but the meta stable $Al_3Nb$ was not fabricated by adding transition metals.

• Korean Journal of Materials Research
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• v.17 no.9
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• pp.453-457
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• 2007

Interest in use of ink-jet printing for pattern-on-demand fabrication of metal interconnects without complicated and wasteful etching process has been on rapid increase. However, ink-jet printing is a wet process and needs an additional thermal treatment such as an annealing process. Since a metal ink is a suspension containing metal nanoparticles and organic capping molecules to prevent aggregation of them, the microstructure of an ink-jet printed metal interconnect 'as dried' can be characterized as a stack of loosely packed nanoparticles. Therefore, during being treated thermally, an inkjet-printed interconnect is likely to evolve a characteristic microstructure, different from that of the conventionally vacuum-deposited metal films. Microstructure characteristics can significantly affect the corresponding electrical and mechanical properties. The characteristics of change in microstructure and electrical resistivity of inkjet-printed silver (Ag) films when annealed isothermally at a temperature between 170 and $240^{\circ}C$ were analyzed. The change in electrical resistivity was described using the first-order exponential decay kinetics. The corresponding activation energy of 0.44 eV was explained in terms of a thermally-activated mechanism, i.e., migration of point defects such as vacancy-oxygen pairs, rather than microstructure evolution such as grain growth or change in porosity.