• 한국세라믹학회지
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• 제56권2호
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• pp.197-204
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• 2019

An electrochemical oxygen permeating membrane (OPM) is fabricated using Zr_0.895Sc_0.095Ce_0.005Gd_0.005O_2-δ (ScCeGdZ) as the solid electrolyte and aLa_0.7Sr_0.3MnO₃-bScCeGdZ composite (LZab, electrode) as the electrode. The crystal phase of the electrode and the microstructure of the membrane is investigated with X-ray diffraction and scanning electron microscopy. The electrochemical resistance of the membrane is examined using 2-p ac impedance spectroscopy, and LZ55 shows the lowest electrode resistance among LZ82, LZ55 and LZ37. The oxygen permeation is studied with an oxygen permeation cell with a zirconia oxygen sensor. The oxygen flux of the OPM with LZ55 is nearly consistent with the theoretical value calculated from Faraday's Law below a critical current. However, it becomes saturated above the critical current due to the limit of the oxygen ionic conduction of the OPM. The OPM with LZ55 has a very high oxygen permeation flux of ~ 3.5 × 10^-6 mol/㎠s in I = 1.4 A/㎠.

• Macromolecular Research
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• 제12권1호
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• pp.46-52
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• 2004

In a continuation of our previous studies on blood compatibility profiles of anion-substituted poly(vinyl alcohol) (PVA) membranes, in which hydroxyl groups have been replaced with carboxymethyl (C-PVA) and sulfonyl groups (S-PVA), we have studied the activation of complement components and the changes in white cell and platelet count in vitro and compared them with those of unmodified PVA, Cuprophane, and low-density polyethylene. Complement activation of fluid phase components, C3a, Bb, iC3b, and SC5b-9, and of bound phases, C3c, C3d, and SC5b-9, were assessed by enzyme-linked immunosorbent assay (ELISA) and immunoblot, respectively. The changes in the number of white cells and platelets following complement activation were counted using a Coulter counter. C-PVA and S-PVA activated C3 to a lesser extent than did PVA, which we attribute to the diminished level of surface nucleophiles of the samples. In addition, C- and S-PVA exhibit increased inhibition of Bb production, resulting in a decrease in the extent of C5 activation. Consequently, because of the reduced activation of C3 and C5, C- and S-PVA samples cause marked decreases in the SC5b-9 levels in plasma. We also found that the negatively charged sulfonate and carboxylate groups of the samples cause a greater extent of adsorbtion of the positively charged anaphylatoxins, C3a and C5a, because of strong electrostatic attraction, which in turn provides an inhibition of chemotaxis and activation of leukocytes. The ability to inhibit complement production, together with the binding ability of anaphylatoxins of the C- and S-PVA samples, leads to a prominent decrease in lysis of leukocytes as well as activation of platelets.

• Korean Chemical Engineering Research
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• 제48권5호
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• pp.654-659
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• 2010

박막형 유기 태양전지의 효율 향상을 위하여 정공 수송층인 CuPc 층에 p형 유기 반도체인 rubrene을 함량 별로 도핑하여 ITO/PEDOT:PSS/CuPc: rubrene/CuPc:C60(blending ratio 1:1)/C60/BCP/Al의 이종접합구조를 가지는 p-i-n형 유기 박막형 태양전지 소자를 제조한 후, 유기 태양전지의 전류 밀도-전압(J-V) 특성, 단락 전류($J_{sc}$), 개방 전압($V_{oc}$), 충진 인자(fill factor:FF), 에너지 전환 효율(${\eta}_e$) 등을 측정하고 계산하여 성능 평가를 수행 하였다. 정공 수송층으로 사용된 CuPc 층에 rubrene을 도핑함으로써 에너지 흡수 스펙트럼에서 흡수 강도가 감소하였다. 그러나 CuPc 보다 큰 밴드갭을 가지며 높은 정공 이동도를 가지는 결정성 rubrene의 도핑에 의해 제조된 p-i-n형 유기 박막 태양전지의 성능은 향상 되는 것으로 확인되었다. 제조된 유기 태양전지의 에너지 전환 효율(${\eta}_e$)은 1.41%로 실리콘 태양전지와 비교해서 아직도 성능 향상을 위한 많은 노력이 필요함을 보여 준다.

• IMMUNE NETWORK
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• 제3권1호
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• pp.69-77
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• 2003

Background: Celecoxib, a COX-2 specific inhibitor, has recently been used for the treatment of rheumatoid arthritis. However, the molecular and cellular mechanisms of celecoxib against RA inflammation remain to be defined. To elucidate the action mechanism of celecoxib on inflammatory cells, we investigated the effect of celecoxib on the production of two important mediators of inflammation, nitric oxide and PGE2 Methods: RAW 264.7 cells stimulated with LPS were preincubated with various concentrations of celecoxib (from $10^{-8}$ to $10^{-5}$ M) and $10{\mu}M$ hydrocortisone, respectively. The production of NO and PGE2, the end products of iNOS and COX-2 genes, were estimated in culture supernatants by Greiss method and EIA, respectively. The expression of iNOS gene, COX-2 gene, $NF-{\kappa}B$, and $I-{\kappa}B$ were determined by RT-PCR and western blot analysis. Results: Celecoxib and hydrocortisone inhibited the production of NO and PGE2 in dose dependent manner, when RAW 264.7 cells were stimulated with LPS. The expression of iNOS was also down-regulated by celecoxib and hydrocortisone. Interestingly, COX-2 gene differentially expressed according to the dose of celecoxib, a decrease with lower dose ($10^{-8}$ M) but an increase with higher dose ($10^{-5}$ M). $NF-{\kappa}B$ binding activity was decreased by lower dose of celecoxib, whereas was not affected by higher dose of it. The expression of $I-{\kappa}B$ was suppressed by higher dose of celecoxib. Conclusion: The celecoxib strongly suppressed the production of NO and PGE2 in LPS-stimulated RAW264.7 cells. The decrease of NO seems to be linked to the inhibition of iNOS by celecoxib. The lower and higher dose of celecoxib differentially regulated the COX-2 expression and $NF-{\kappa}B$ activity.

• 폴리머
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• 제33권3호
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• pp.191-197
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• 2009

박막형 유기 태양전지의 성능 향상을 위하여 정공 수송층인 CuPc 층에 강한 p형 유기 반도체인 $F_4$-TCNQ을 도핑하여 ITO/PEDOT:PSS/CuPc: $F_4$-TCNQ(5wt%)/CuPc:C60 (blending ratio 1 : 1)/C60/BCP/LiF/Al의 이종 접합 구조를 가지는 P-i-n형 유기 박막형 태양전지 소자를 진공증착 장비를 이용하여 제조한 후, 유기 태양전지의 전류 밀도-전압(J-V) 특성, 단락 전류($J_{sc}$), 개방 전압($V_{oc}$), 충진 인자(fill factor: FF), 에너지 전환 효율(${\eta}_e$) 등을 측정하고 계산하여 성능 굉가를 수행하였다. CuPc 층에 $F_4$-TCNQ을 도핑함으로써 에너지 흡수 스펙트럼에서 흡수강도가 증가하였으며, $F_4$-TCNQ가 도핑된 CuPc 박막에서 $F_4$-TCNQ 유기 분자의 분산성 향상, 박막의 표면 균일성, 주입 전류(injection currents) 향상 효과등에 의해서 제조된 p-i-n형 유기 박막 태양전지의 성능이 향상되는 것으로 확인되었다. 제조된 유기 태양전지의 에너지 전환 효율(${\eta}_e$)은 0.15%로 실리콘 태양전지와 비교해서 아직도 성능 향상을 위한 많은 노력이 필요함을 보여 준다.

• 전력전자학회논문지
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• 제19권1호
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• pp.51-56
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• 2014

PV cell modeling is necessary both for software and hardware simulators in analyzing and testing the performance of PV generation systems. Unique I-V curve of a PV cell identifies its own characteristics by electrical equivalent model that is composed of diode constants ($I_o$, $v_t$), photo-generated current ($I_{ph}$), series resistance ($R_s$), and shunt resistance ($R_{sh}$). Photo-generated current can be easily estimated since it is proportional to irradiation level. However, other electrical parameters should be solved from the manufacturer's data sheet that is consisted with three remarkable operating points such as open circuit voltage ($V_{oc}$), short circuit current ($I_{sc}$), and maximum power voltage/current ($V_{MPP}/I_{MPP}$). This paper explains and analyzes mathematical process of a novel PV cell modeling algorithm that was proposed by the authors with the name of "K-algorithm".

• The Journal of Asian Finance, Economics and Business
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• 제7권1호
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• pp.229-238
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• 2020

A model is presented in this paper to provide understanding of the supply chain integration and supply chain information practices' impact on the manufacturing industries. The supply chain information practices play a crucial role in sharing information between the members of SC network. Thus, it is important to develop a comprehensive understanding of the differences and similarities among ISI and information management. It will allow firms to systematically evaluate and carefully choose the information strategy. The empirical findings of this research offer essential and interesting insights about what role SCI, supply chain information and Supply chain ISI play in determining Malaysia's financial performance. The theoretical gaps addressed in this study are of significant importance, since a little empirical evidence is available regarding system infrastructure and supply chain information management's effectiveness. This research provides further paths of exploring system infrastructure and information management, thereby defining the manufacturing industries' next step in SCM struggle i.e. modifying total integrated SC principle in other manufacturing firms. The Resource-based theory discovered organizational resources as an essential organizational success ingredient. Therefore, in order to recognize its potential value, internal resources, for instance, information system and management must be fully utilized.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.1007-1010
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• 2006

This study investigates the spatial structure of the total cloud liquid water content Q fields over the Northwest Pacific Ocean during winter monsoon. The distributions of Q have been estimated from the brightness temperatures of the ocean - atmosphere system $T_B(f)$, where f is frequency, measured by AQUA AMSR-E in January -March 2003. Marine strati (St) and stratocumuli (Sc) are typical for winter monsoon season. They were analysed using mainly high-frequency channel at f = 36.5 GHz, vertical polarisation. $T_B$ data were accompanied by the data on near surface wind speed, air temperature and humidity from the nearest meteorological stations. Tow one-dimensional spectra were computed for downwind and crosswind sections of Q fields. The AMSR-E antenna field of view (14-8 km) and the cloud field sizes (100-1000 km) restricted the spatial scales. The results of case study Jan 31 2003 are presented. Scale-invariant spectrum is typical. In the cases of extended St levels a spectral slope equals about -1.7, conforming to classical -5/3 of turbulence theory. For Sc cases the absolute magnitude of spectral slope is rather higher, as a rule. The value is about -2. In the case when cloud streets are presented, a strait line form of spectrum is less reliable with a slope being rather lower (about -1.4).

• 컴퓨터교육학회논문지
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• 제8권3호
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• pp.91-100
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• 2005

대학교육에 있어서, 학습자 중심의 교육과정으로 개편하려는 노력이 이루어지고 있는데, 이러한 노력은 대학교육의 질을 제고하고 대학의 경쟁력과 학습자의 전문성을 향상시키기 위한 하나의 전략으로 평가된다. 가장 단순한 형태인 과목 중심의 운영 방식인 현재의 선택 방식을 개선한 SSC 교육과정을 제안하고 그 교육적 효과를 측정해보았다. 그 결과, SSC 교육과정을 이수한 학습자들의 학업성취도가 SC 교육과정을 이수한 학습자보다 높은 것으로 나타났다.

• Bulletin of the Korean Chemical Society
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• 제32권2호
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• pp.576-582
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• 2011

Various 2-amino-6-[3-(substituted phenyl)-5-phenyl-4,5-dihydropyrazol-1-yl]-4-(substituted phenyl)nicotinonitriles (3a-t) were designed and synthesized by clubbing two active anticonvulsant pharmacophores pyrazole and pyridine. All the synthesized compounds possessed the pharmacophoric elements essential for good anticonvulsant activity. The anticonvulsant screening was performed by maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole (scPTZ) tests. Two compounds 3i and 3s showed significant anticonvulsant activity in both the screens with $ED_{50}$ values 17.5 mg/kg and 22.6 mg/kg respectively in MES screen and 154.1 mg/kg and 242.6 mg/kg respectively in scPTZ screen. They were also found to have no acute toxic effects in mice when tested at elevated doses.