• 한국재료학회지
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• 제15권3호
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• pp.155-160
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• 2005

The electrolytic reduction of spent oxide fuel involves the liberation of oxygen in a molten LiCl electrolyte, which results in a chemically aggressive environment that is very corrosive fir typical structural materials. So, it is essential to choose the optimum material f3r the process equipment handling molten salt. In this study, the corrosion behavior of Al-Y coated Haynes 263 in a molten salt of $LiCl-Li_2O$ under oxidation atmosphere was investigated at $650^{\circ}C$ for $72\~168$ hours. The corrosion rate of Al-Y coated Haynes 263 was low while that of bare Haynes 263 was high in a molten salt of $LiCl-Li_2O$. Al-Y coated Haynes 263 improved the corrosion resistance better than bare Haynes 263 alloy. An Al oxide layer acts as a protective film which Prohibits Penetration of oxygen. Corrosion Products were formed $Li(Ni,Co)O_2$ and $LiTiO_2$ on bare Haynes 263, but $LiAlO_2,\;Li_5Fe_5O_8\;and\;LiTiO_2$ on Al-Y coated Haynes 263.

• IMMUNE NETWORK
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• 제4권2호
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• pp.108-115
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• 2004

Background: Production of nitric oxide (NO) by inducible NO synthase (iNOS) has been implicated in the pathology of autoimmune disease. It is unknown whether iNOS expression is increased within testes and whether iNOS and NO have essential roles in the pathogenesis of EAO. Methods: EAO was induced in guinea pig testes at 17 days after secondary immunization by administration of crude extract (CE) and purified glycoprotein 1 (GP1) from normal guinea pig testes. iNOS gene expression was assessed by RT-PCR and Northern blot analysis in testes. Localization of iNOS and Mac-1 and the indicator of NO-mediated tissue injury, nitrotyrosine, were detected in the testicular lesion by immunohistochemistry. Results: In control testes, inflammation and iNOS gene expression were not detected, whereas, in CE- and GP1-injected testes, inflammation and marked iNOS gene expression were evident at day 17 after secondary immunization. Immunohistochemistry of Mac-1 showed the colocalization with iNOS protein and nitrotyrosyl proteins in intertubules, suggesting that NO produced by infiltrated macrophages may be involved in inflammatory lesions of intertubules. Intraperitoneal administration of aminoguanidine significantly prevented EAO with reduction of inflammation, iNOS expression and nitrotyrosine formation. Conclusion: These results suggest that NO production by macrophages may be important in the pathogenesis of CE- and GP1-induced EAO. Furthermore, this study demonstrated the therapeutic potential of iNOS inhibitor in the treatment of inflammatory and autoimmune mediated-diseases.

• Archives of Pharmacal Research
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• 제28권1호
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• pp.100-105
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• 2005

Mancozeb (MCZ) is known to have detrimental effects on the reproductive system, but the toxicity of MCZ on immune responses has not been systematically investigated. We investigated the effects of MCZ exposure on the activities of murine peritoneal macrophages through evaluation of MCZ-induced alteration of nitric oxide (NO) production and tumor necrosis $factor-{\alpha}(TNF-\alpha)$ synthesis. Macrophages were examined ex vivo from mice orally treated with various doses of MCZ for 5 consecutive days per week for 4 weeks (subacute exposure, 250, 1000, 1500 mg/kg/day) followed by culture for 2 $(TNF-{\alpha})$ or 3 days (NO) in the presence of LPS plus $IFN-{\gamma}$. Macrophages from naive mice were also cultured with various concentrations of MCZ (0.05, 0.25, 0.5, 1 and 2 ${\mu}g//mIL$ in the presence of LPS plus $IFN-{\gamma}$ for 2 $(TNF-{\alpha})$ or 3 days (NO) in vitro. NO production was decreased with the in vitro exposure to all concentrations of MCZ. However, the amount of NO production by peritoneal macrophages from MCZ-subacutely exposed mice was increased in comparision with that of control group. In vitro, MCZ suppressed $(TNF-\alpha)$ secretion with significant reduction at 2 ${\mu}g/mL$ MCZ. Conversely, $(TNF-{\alpha})$ release was enhanced ex vivo. This study provides the substantial evidence on MCZ-induced alternation in macrophage activity. In order to clearly understand the contrasting effect of MCZ on peritoneal macrophage activity, it is necessary to further investigate the influence of major metabolite of MCZ (ETU) exposure on the NO production and $(TNF-{\alpha})$ synthesis.

• 한국정보통신학회논문지
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• 제14권1호
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• pp.191-196
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• 2010

본 연구에서는 타겟 제작에 드는 비용을 줄이고, 타겟 이용의 효율성을 높이기 위해 기존의 소결된 세라믹 타겟 대신 분말 타겟으로 사용하여 알루미늄 도핑된 산화아연(Aluminum doped zinc oxde; AZO)박막을 마그네트론 스퍼터법에 의해 제조하고, 스퍼터 압력에 따른 박막 물성을 조사하였다. 유리 기판에 증착된 AZO 박막은 타깃 종류 및 스퍼터 압력에 관계없이 기판에 수직한 c-축 방향으로 우선 성장방위를 갖는 hexagonal 구조로 성장되었다. 스퍼터 압력이 증가함에 따라 이 면 방향으로의 결정성장이 촉진되었다. AZO 박막의 전기적, 광학적 특성은 스퍼터 압력 증가에 따라 향상되었으며, 15 mTorr에서 $6.5{\times}10^{-1}\;{\Omega}-cm$의 최소의 비저항 값을 나타내었다.

• 한국세라믹학회지
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• 제47권1호
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• pp.26-38
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• 2010

Degradation in Solid Oxide Fuel Cell performance can be ascribed to the following fundamental processes from the materials chemical point of view; that is, diffusion in solids and reaction with gaseous impurities. For SOFC materials, diffusion in solids is usually slow in operation temperatures $800\sim1000^{\circ}C$. Even at $800^{\circ}C$, however, a few processes are rapid enough to lead to some degradations; namely, Sr diffusion in doped ceria, cation diffusion in cathode materials, diffusion related with metal corrosion, and sintering of nickel anodes. For gaseous impurities, chromium containing vapors are important to know how the chemical stability of cathode materials is related with degradation of performance. For LSM as the most stable cathode among the perovskite-type cathodes, electrochemical reduction reaction of $CrO_3$(g) at the electrochemically active sites is crucial, whereas the rest of the cathodes have the $SrCrO_4$ formation at the point where cathodes meet with the gases, leading to rather complicated processes to the degradations, depending on the amount and distribution of reacted Cr component. These features can be easily generalized to other impurities in air or to the reaction of nickel anodes with gaseous impurities in anode atmosphere.

• 한국융합학회논문지
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• 제11권7호
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• pp.157-162
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• 2020

최근 레이저를 이용하여 환원된 친환경 그래핀 패턴 기술(Laser Induced Graphene, LIG)은 간단하고 효율적으로 원하는 형태로 다양한 기판 위에 패터닝하는 것이 가능하여 신축 유연 전자 소자, 박막 형태의 에너지 저장 소자 등과 같이 새로운 친환경 전자 소자 제작에 많이 활용되고 있다. 이러한 그래핀 패턴 구조를 이용한 전자 소자의 성능과 효용성을 높이기 위해서는 그래핀 고유의 2차원 특성을 유지하면서 가능한 최소한의 선폭을 구현할 수 있는 최적화된 레이저 패터닝 조건에 대한 연구가 필수적이다. 본 논문에서는 최근 레이저 그래핀 패턴 연구에서 많이 사용되는 Ti:sapphire 펨토초 레이저를 이용해서 그래핀 광-열 산화반응을 분석하여 최적화된 그래핀의 최소선폭을 구현하였다. 레이저 에너지의 확산 효과를 최소화하기 위하여 레이저 광강도와 레이저 스캔 속도를 조절하여 최적의 그래핀 특성을 나타내는 패턴을 연구하였으며 18 ㎛의 집속된 빔을 이용하여 최소 30 ㎛의 이차원 그래핀 선폭을 구현하였다.

• Toxicological Research
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• 제26권1호
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• pp.37-46
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• 2010

This study aimed to elucidate anti-inflammatory activities from extracts of Asterina pectinifera on nitric oxide (NO) production, TNF-${\alpha}$ and IL-6 release in lipopolysaccharide (LPS)-stimulated murine macrophage cell, RAW264.7. We prepared the methanolic extracts (60-MAP, 70-MAP, 80-MAP and 90-MAP), aqueous extract (W-AP) and functional bioactive compound fraction (He-AP and EA-AP) from Asterina pectinifera according to extract method. The 60-MAP, 70-MAP, 80-MAP, 90-MAP and W-AP were significantly suppressed LPS-induced production NO, TNF-${\alpha}$ and IL-6 secretion in a concentration-dependent manner (P < 0.05). Especially, 80-MAP by extracted 80% methanol had the strongest activity in reduction of inflammatory mediators among these extracts. Indeed, to identify active fraction, which contained potential bioactive compounds, from 80-MAP of Asterina pectinifera, we tested anti-inflammatory activity of the He-AP or the EA-AP. The He-AP was next extracted from 80-MAP and the EA-AP were extracted from the other methanol layer except the He-AP. The EA-AP demonstrated a strong anti-inflammatory effect through its ability to reduce NO production and it also inhibited the production of proinflammatory cytokines such as IL-6 and TNF-${\alpha}$ at low concentration. These results suggested that the methanolic extract from Asterina pectinifera had the potential inhibitory effects on the production of these inflammatory mediators.

• 한국축산시설환경학회지
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• 제8권2호
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• pp.115-118
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• 2002

This study was conducted to determine the effects of pig manure composting on emission of dinitrogen oxide ($N_2O$) that is greenhouse gas. Fresh pig manure was mixed with sawdust as bulking agent and moisture content of mixed compost was adjusted by 61.9%. After mixing bulking agent with pig manure that was left to compost with aeration in composting chamber for an initial period of 30 days. At the end of this period, that was decomposed and a second period of composting was conducted without aeration for 60 days. Temperature during the initial composting period was above $55^{\circ}C$ for 7 days. Moisture reduction rate by composting pig manure was 36.7%. $N_2O$ Produced during composting was 0.043g/T-Ng.

• 대한전자공학회논문지SD
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• 제43권4호
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• pp.23-30
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• 2006

본 연구에서는 나노 스케일 MuGFET(Mutiple-Gate FETs)의 단채널 효과와 corner effect를 3차원 시뮬레이션을 통하여 분석하였다. 문턱전압 모델을 이용하여 게이트 숫자(Double-gate=2, Tri-gate=3, Pi-gate=3.14, Omega-gate=3.4, GAA=4)를 구하였으며 추출된 게이트 숫자를 이용하여 각각의 소자 구조에 맞는 natural length($\lambda$)값을 얻을 수 있었다. Natural length를 통하여 MuGFET의 단채널 효과를 피할 수 있는 최적의 소자 구조(실리콘 두께, 게이트 산화막의 두께 등)를 제시 하였다. 이러한 corner effect를 억제하기 위해서는 채널 불순물의 농도를 낮게 하고, 게이트 산화막의 두께를 얇게 하며, 코너 부분을 약 17%이상 라운딩을 해야 한다는 것을 알 수 있었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.382.2-382.2
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• 2014

We explain a method to fabricate multi-layered transparent conductive films (TCF) using graphene oxide (GO), copper powder and polyurethane (PU) solution. The flexible graphene nanosheets (GNSs) serve as nanoscale connection between conductive copper nanoparticles (CuNps) and PU nanofibers, resulting in a highly flexible TCF. To fabricate conductive films with high transmittance, polyurethane (PU) nanofibers were used for a conductive network consisting of CuNps and GNSs (CuNps-GNSs). In this experiment, copper powder and graphene oxides were mixed in deionized water with the ultrasonication for 2 h. NaBH4 solution is used as a reduction agents of CuNps and GNSs (CuNps-GNSs) under a nitrogen atmosphere in the oil bath at 100% for 24 h to mixed. The purified and dispersed CuNp-GNS were obtained in deionized water, and diluted to a 10wt.% based on the contents of GNSs. Polyurethane (PU) nanofibers on a PET substrate were formed by electrospinning method. PET slides coated with the PU nanofibers were immersed into CuNp-GNS solution for several second, rinsed briefly in deionized water, and dried to obtain self-assembled CuNp-GNS/PU films. The morphology of the multi-layered films were characterized with a field emission scanning electron microscope (FE-SEM, Hitachi S-4700) and atomic force microscope (AFM, PSIA XE-100). The electrical property was analysed by the I-V measurement system and the optical property was measured by the UV/VIS spectroscopy.