• Journal of Korean Society of Environmental Engineers
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• v.38 no.5
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• pp.242-248
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• 2016

The overall reaction rate of fuel cell is governed by oxygen reduction reaction (ORR) in the cathode due to its slowest reaction compared to the oxidation of hydrogen in the anode. The ORR efficiency can be readily evaluated by examining the adsorption strength of atomic oxygen on the surface of catalysts (i.e., known as a descriptor) and the adsorption energy can be controlled by transforming the surface geometry of catalysts. In the current study, the effect of the surface geometry of catalysts (i.e., strain effect) on the adsorption strength of atomic oxygen on platinum catalysts was analyzed by using density functional theory (DFT). The optimized lattice constant of Pt ($3.977{\AA}$) was increased and decreased by 1% to apply tensile and compressive strain to the Pt surface. Then the oxygen adsorption strengths on the modified Pt surfaces were compared and the electron charge density of the O-adsorbed Pt surfaces was analyzed. As the interatomic distance increased, the oxygen adsorption strength became stronger and the d-band center of the Pt surface atoms was shifted toward the Fermi level, implying that anti-bonding orbitals were shifted to the conduction band from the valence band (i.e., the anti-bonding between O and Pt was less likely formed). Consequently, enhanced ORR efficiency may be expected if the surface Pt-Pt distance can be reduced by approximately 2~4% compared to the pure Pt owing to the moderately controlled oxygen binding strength for improved ORR.

• Journal of Conservation Science
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• v.35 no.6
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• pp.612-620
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• 2019

A woolen tapestry curtain, owned by the Seoul Museum of Craft Art, is composed of tabby by cotton-warp and wool-weft threads and its patterned part is shown as a tapestry; paint with pigment has been added to it. The chromaticity of this curtain was measured and the substances in the deep red color were confirmed as Hg by an analysis of the ingredients through X-ray fluorescence. This is presumed to be cinnabar or vermilion. Analyses were performed on a total of seven fabric samples, including the warp & weft of the fabric, its trimming, and its back fabric. As a result, the warp of the woolen tapestry curtain was determined to be a cotton fiber with a middle hole or lumen in the cross-section. Furthermore, an infrared peak likewise showed O-H and C-O binding. Wool fibers as wefts were identified with circular and oval cross-sections and IR peaks showed N-H/O-H stretching and amide(-CONH-). The animal hair samples used in the wool fiber are believed to have come from long-tailed goral or goats and the possibility of using easy-to-spin sapsal dog hair is also not to be overlooked. This was determined through a contrast analysis by the Cultural Heritage Administration to identify the animal species used in the tapestry.

• Analytical Science and Technology
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• v.26 no.1
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• pp.106-112
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• 2013

PDE plays an important role in cAMP-mediated cellular signaling within the cells. The proper targeting of each PDE is mediated by unique N-terminal of each PDE isoform. It has been recently reported that supershort-, short- and long-forms of PDE4 in Aplysia were cloned in Aplysia. Long-form of ApPDE4 was localized at plasma membrane and presynaptic terminal in Aplysia sensory neurons. However, it remains elusive which part of ApPDE4 is minimal region for the proper targeting and what are the effects on the cell functions. Here, we identified that N-terminal 13 amino acids of ApPDE4 long-form is minimal regions for the plasma membrane targeting. In addition, overexpression of ApPDE4(N20)-mRFP could induce morphological changes in HEK293T cells. Interestingly, mRFP-$PLC{\delta}1$(PH), which selectively binds to PI4,$5P_2$, could induce morphological changes in similar with that by ApPDE4(N20)-mRFP. These results suggested that binding of ApPDE4(N20) to lipids including PI4,$5P_2$ might be responsible for targeting of ApPDE4 to plasma membrane and morphological changes in HEK293T cells.

• Journal of Yeungnam Medical Science
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• v.11 no.2
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• pp.352-362
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• 1994

To evaluate the effects of pregnancy-induced hypertension (PIH) to the iron status of fetuses, umbilical cord blood of 35 newborn infants borne by PIH mothers and of 37 normal term infants delivered at Yeungnam University Hospital from September 1, 1993 to September 30, 1994, were studied. The serum hemoglobin concentration of women with PIH was significantly higher than normal full-term pregnant women. There was no significant difference in serum hemoglobin concetration between women with PIH and normal full-term pregnant women and their newborn infants. There was no significant difference in serum hemoglobin concentration beween infants of women with PIH and normal full-term infants. The serum iron concentration of newborn infants of women with PIH was higher and the serum ferritin concentration of newborn infants of women with PIH was lower than normal full-term infants, but there were no significant difference between the two groups. The serum total iron-binding capactity and unsaturated iron-binding capacity of infants of women with PIH were significantly higher than normal full-term infants. The newborn infants of PIH women seemed that they might have occult depletion of iron store and need meticulous follow up during early neonatal period.

• Korean Journal of Optics and Photonics
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• v.31 no.5
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• pp.213-217
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• 2020

In this study we report a wet-etching-based fabrication method for adiabatic optical-fiber tapers (OFTs), and describe their adiabaticity and HE₁₁ mode evolution at a wavelength of 1550 nm. The profile of the fabricated system satisfies the adiabaticity properties well, and the far-field pattern from the etched OFT shows that the fundamental HE₁₁ mode is maintained without a higher-order mode coupling throughout the tapers. In addition, the measured far-field pattern agrees well with the simulated result. The proposed adiabatic OFTs can be applied to a number of photonic applications, especially fiber-chip packages. Based on the fabricated adiabatic OFT structures, the optical transmission to the inversely tapered silicon waveguide shows large spatial-dimensional tolerances for 1 dB excess loss of ~60 ㎛ (silicon waveguide angle of 1°) and insertion loss of less than 0.4 dB (silicon waveguide angle of 4°), from the numerical simulation. The proposed adiabatic coupler shows the ultrabroadband coupling efficiency over the O- and C-bands.

• Journal of Korea Foresty Energy
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• v.24 no.1
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• pp.39-46
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• 2005

In this study, the possibility of sugar conversion of poplar wood(Populus $alba{\times}rglandulosa$) and their degradation features of major wood components were characterized using flow type supercritical water treatment system. The finely ground poplar wood meals were treated for 2min. under subcritical condition$(23MPa,\;275^{\circ}C\;and\;325^{\circ}C)$ and supercritical condition $(23MPa,\;375^{\circ}C\;and\;415^{\circ}C)$. respectively. The degradation products of poplar wood meals appeared brownish colors, including undegraded solids. Increasing the temperature of the system, the degradation rate of poplar wood meals was accelerated and reached up to $94\%\;at\;375^{\circ}C$. The total amount of reducing sugars in degradation products determined by DNS method were gradually lowered when the temperature condition became severe. This indicated that the reducing sugars formed were further degraded to kan derivatives by certain side reaction such as pyrolysis under higher temperature. In order to characterize degradation features of lignin, the degradation products were extracted with ethylacetate and the organic phases were subjected to GC-MS analysis. Main lignin degradation products were identified to vanillin, guaiacol, syrinaldehyde, 4-prophenyl syringol and dihydrosinapyl alcohol, which could be formed by the cleavage of ether linkages in lignin polymers by high temperature condition.

• Journal of the Korean Magnetics Society
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• v.7 no.3
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• pp.152-158
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• 1997

NiFeCo/ Cu /Co trilayers were formed on 4$^{\circ}$ tilt-cut Si(111) substrates with a Cu(50$\AA$) underlayer and large-scaled test magnetoresistive RAM (MRAM) cells were fabricated using a conventional lithographic process. NiFeCo / Cu /Co trilayers deposited on the same templates without any applied magnetic field showed strong in plane uniaxial magnetic anisotropy and excellent magnetoresistive (MR) properties such as high MR ration and sensitivity within a low external magnetic field, which are suitable properties for a MRAM application. In order to obtain optimized MR results in NiFeCo /Cu /Co trilayers, the thickness of Cu spacer was varied. Interlayer coupling between two magnetic layers was observed and it was found that the MR properties were strongly dependent on the coupling force, especially near 20 $\AA$ of Cu spacer thickness. Test MRAM cells were fabricated using the optimized NiFeCo (60$\AA$)/ Cu (25$\AA$)/ Co (30$\AA$) trilayer thin films. With a 10 mA of sense current and 5$\times$$10^5$ of word current, 10 mV of signal output was obtained, which implies the strong potentials of NiFeCo/ Cu /Co trilayer thin films for a MRAM application.

• Korean Journal of Agricultural Science
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• v.29 no.2
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• pp.78-90
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• 2002

This study was carried out to investigate whether peptide produced from wheat protein by enzyme hydrolysis can be used as a natural antimicrobial agent. Antimicrobial peptide was obtained from wheat protein by protease of 7 species. The produced antimicrobial peptide was purified through ultrafiltration, membrane filtration and HPLC, and molecular weight and amino acid sequence of the purified antimicrobial peptide were determined. Among hydrolysate produced from wheat protein by protease of 7 species, antimicrobial activity was observed for the peptide obtained from Asp. saito protease. The Asp. saito protease did production antimicrobial hydrolysate showing the highest antimicrobial activity at reaction condition of $37^{\circ}C$ and pH 6.0, but not at reaction condition above $50^{\circ}C$. Wheat protein hydrolysate was fractionated by membrane filtration and showed antimicrobial activity between molecular weight 1,000 - 3,000. The antimicrobial activity fraction obtained by membrane filtration was separated through HPLC and showed antimicrobial activity in the peak of retention time 31.1 - 31.8 min. Since after wheat protein protease hydrolysate was heated during 15 min at $121^{\circ}C$, antimicrobial activity was maintained, we could be conviction as heat-stable peptide. Molecular weight of antimicrobial peptide identified by MALDI-mass was 1,633. Amino acid sequence of antimicrobial peptide was cysteine, glycine, prolin, prolin, prolin, valine, valine, alanine, alanine and arginine.

• Korean Journal of Social Welfare
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• v.67 no.2
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• pp.161-181
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• 2015

This article tries to identify the regulating mechanism of the welfare states on the private spheres of individuals and families. When the welfare state is to be understood as an institutional arrangement which is based upon the 'modernity', the reflectivity on the welfare state is about to be on the modernity and on the institutions as well. Authors assume the welfare state as an historical and developmental type of modern states. The critical components of modernity embedded in birth and growth of modern welfare states projected to their institutions are identified. Welfare states dissociates the political dynamics which have built the foundation of the welfare state itself, and faces against the new political dynamics of the individualized society. Finally, welfare state confronts the institution failure due to its intrinsic characteristics, and consequently individuals and families come across the institution dependency. Individuals in the overly rationalized spheres are being depoliticized, and they are identified themselves as the subjects of status-struggles of the institutions other than the subjects of the political dynamics of welfare states.

• 한국HCI학회:학술대회논문집
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• 2007.02b
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• pp.70-77
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• 2007

모바일 IT와 무선인터넷의 발달에 따라 디지털 컨텐츠를 담는 뉴미디어로서의 휴대폰의 가능성은 점차 확대되고 있으며, 모바일 컨텐츠 시장도 급속도로 성장하고 있다. 무선인터넷의 발달은 유선 인터넷 컨텐츠를 무선으로 확장하게 하였으며, 장소기반 관광 정보 (Location Based Information) 서비스가 우선적으로 구축되고 있다. 그러나, 현재 모바일 기기로 서비스되고 있는 대부분의 관광정보는 관광지에 대한 간단한 설명, 교통편, 숙박, 음식점 등 매우 실용적이고 일반적이어서 편리하긴 하지만, 그다지 사용하고 싶은 매력은 없는 정보에 그치고 있다. 본 연구는 기술적으로 진화하고 있는 유비쿼터스 도시 환경에서 모바일을 활용하여 어떠한 새로운 형태의 관광 컨텐츠가 가능해질 수 있을까 하는 질문에서 출발하였다. 본 논문은 정보통신연구 진흥원의 지원을 받아 진행했던 지역의 역사, 문화 정보 전달을 위한 모바일 투어 게임 "타임트렉" 프로토타입 개발에 관한 리서치, 컨셉, 프로세스를 정리한 것이다. "타임트렉" 프로젝트에서 추구했던 방향은 문화적, 역사적으로 중요한 장소를 투어하면서 모바일 미디어를 활용하여 보다 깊은 역사, 문화 정보를 새롭고 재미있는 방법으로 전달하고자 하는 것이었다. 특히, 사용자의 보다 적극적인 참여와 흥미유발을 위해 시간여행 능력을 가진 탐정이 과거로 시간여행을 통해 사건을 해결하는 롤플레잉 스토리 기반 게임과 물리적 장소에서 답을 찾아야 하는 오프라인 퀘스트 게임의 형식을 포함하는 모바일 투어 게임형태로 구축하였다. 이렇게 함으로써 관광객들에게 보다 그 장소에 대해 알고 싶어 하는 흥미를 유도하고 투어를 완료하게 유도함으로써 만족스럽고 새로운 관광 경험을 제공하는 것을 목적으로 하였다. 새로운 타입의 모바일 관광서비스의 프로토타입 개발에 있어 중점을 두었던 부분은 역사적으로 중요한 장소를 워킹 트레일로 구성하고 그 장소가 가지는 기본적인 문화, 역사적 정보에 오락적 요소(스토리와 게임 요소)를 자연스럽게 혼합하여 흥미로운 컨텐츠를 만들는 것이었으며, 또한 모바일이 가진 위치기반 서비스 기능을 활용하여 효과적으로 컨텐츠를 적재적소에 제시하는 인터페이스 구현에 중점을 두었다. 논문에서는 먼저, 기존의 국내외 모바일 관광정보서비스의 사례 및 연구 동향을 분석하고, 이에 따라 설정한 "타임트렉" 프로젝트의 방향성과, "타임트렉" 프로젝트에서 개발했던 프로토타입에 대하여 요약, 설명하였으며, 사용자 테스트 과정을 기술하였다. 그리고 마지막으로, 시장 세분화에 따른 관광 정보 서비스의 엔터테인먼트화 전략에 대해 논의하였다. 본 연구에서 시도했던 지역의 역사, 문화 관광을 위한 LBS 모바일 기술과 스토리, 게임 등 엔터테인먼트 요소의 결합은 관광객들에게 새로운 형태의 즐거운 관광 경험을 창출할 수 있으며, 관광 산업과 모바일 컨텐츠 산업의 결합이라는 새로운 접근의 장을 개척할 수 있을 것이다.