• 제목/요약/키워드: System T/H Analysis

검색결과 670건 처리시간 0.03초

원통형 고체산화물 연료전지와 마이크로 가스터빈 하이브리드 시스템의 성능해석을 위한 모델링 (Modeling for the Performance Analysis of a Tubular SOFC/MGT Hybrid Power System)

  • 송태원;손정락;김재환;김동섭;노승탁
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.2070-2075
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    • 2004
  • Performance of a solid oxide fuel cell (SOFC) can be enhanced by converting thermal energy of its high temperature exhaust gas to mechanical power using a micro gas turbine (MGT). A MGT plays also an important role to pressurize and warm up inlet gas streams of the SOFC. In this study, the influence of performance characteristics of the tubular SOFC on the hybrid power system is discussed. For this purpose, detailed heat and mass transfer with reforming and electrochemical reactions in the SOFC are mathematically modeled, and their results are reflected to the performance analysis. The analysis target is 220kWe SOFC/MGT hybrid system based on the tubular SOFC developed by Siemens-Westinghouse. Special attention is paid to the ohmic losses in the tubular SOFC counting not only current flow in radial direction, but also current flow in circumferential direction through the anode and cathode.

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전력계통 시뮬레이터의 기술현황과 국내개발의 방법론 고찰 (A Study on the Power System Simulator Technologies for the Domestic Development)

  • 김정훈;이봉용;심건보;신중린;이흥재;권태원;윤용범;이철휴
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1993년도 하계학술대회 논문집 A
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    • pp.529-533
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    • 1993
  • Recently, the analysis of power systems is transfering from analytical techniques to simulation because it is difficult to analyze accurately the phenomena occured in complicated and huge power systems. Digital computers are used popularly to analyze the phenomena of power systems. But real-time simulators were used due to the limitation of digital computer - real time analysis, non-linearity and so on - and rapid development of digital technologies. In this paper, we discuss the advanced foreign power system simulators and the conceptual designs for the KEPCO power system simulator have been drawn for the domestic development.

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소청용탕이 Helper T Cell의 활성에 미치는 영향 (Effect of Herbal Extract on Helper T Cell activity)

  • 서영호;배현수;신민규;홍무창
    • 동의생리병리학회지
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    • 제16권4호
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    • pp.693-700
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    • 2002
  • SCRT (Sochungyong-tang) has been used for immune disease in human. The purpose of this study was effect of Helper T cell, major regulator of immune system. Spleen cell from 8 week BALB/c mice were cultured in SCRT containing medium without activation for 48 h. The MTS assay and flow cytometry revealed that SCRT treated Iympocyte were non-effect in percentage of CD4+ T cell. Subsequently CD4+ T cell were isolated and cultured in SCRT containing medium. SCRT were non-effective on CD4+ T cell without any involvement of APC. In order to evaluate the direct effect of SCRT on Helper T cell, CD4+ T cell isolated after 48 h of culture in SCRT containing medium and activated with and without anti-CD3/anti-CD28 activation for 48 h. A lower level of CD69 was observed in SCRT treated cells in flow cytometry analysis. Subsequently Using RT-PCR analysis the expression of mRNA for IL-2, INF-γ are upregulated and, IL-4 is downregulated in CD4 T cell. The result suggests that SCRT makes Th1 significantly increased and Th2 relatively inhibited. The results suggest that SCRT potentiate Th1 cell and decrease Th2 development at the same time, which is believed to be bemeficial for IgE-mediated responses.

THE HARMONIC ANALYSIS ASSOCIATED TO THE HECKMAN-OPDAM'S THEORY AND ITS APPLICATION TO A ROOT SYSTEM OF TYPE BCd

  • Trimeche, Khalifa
    • Korean Journal of Mathematics
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    • 제27권1호
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    • pp.221-267
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    • 2019
  • In the five first sections of this paper we define and study the hypergeometric transmutation operators $V^W_k$ and $^tV^W_k$ called also the trigonometric Dunkl intertwining operator and its dual corresponding to the Heckman-Opdam's theory on ${\mathbb{R}}^d$. By using these operators we define the hypergeometric translation operator ${\mathcal{T}}^W_x$, $x{\in}{\mathbb{R}}^d$, and its dual $^t{\mathcal{T}}^W_x$, $x{\in}{\mathbb{R}}^d$, we express them in terms of the hypergeometric Fourier transform ${\mathcal{H}}^W$, we give their properties and we deduce simple proofs of the Plancherel formula and the Plancherel theorem for the transform ${\mathcal{H}}^W$. We study also the hypergeometric convolution product on W-invariant $L^p_{\mathcal{A}k}$-spaces, and we obtain some interesting results. In the sixth section we consider a some root system of type $BC_d$ (see [17]) of whom the corresponding hypergeometric translation operator is a positive integral operator. By using this positivity we improve the results of the previous sections and we prove others more general results.

A New Member of Human TSA/AhpC as Thioredoxin-dependent Thiol Peroxidase

  • Jeong, Woo-Jin;Cha, Mee-Kyung;Kim, Il-Han
    • BMB Reports
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    • 제33권3호
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    • pp.234-241
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    • 2000
  • A new type of the human TSA homologous gene was cloned from a HeLa cell cDNA and characterized. The gene product consists of 161 amino acids with a molecular mass of 16,900. The TSA homologous protein, as a new 6th member of the human TSA (hTSA VI), exerted a thioldependent peroxidase activity with the use of thioredoxin system as a physiological electron donor. The values of $V_{max}/K_m$ of hTSA VI for $H_2O_2$ and t-butyl hydroperoxide (t-BOOH) were calculated as $5.53{\times}10^{-2}$ and $3.70{\times}10^{-2}$, respectively. This implies that hTSA VI is a peroxidase, which reduces $H_2O_2$ and t-BOOH. The mutation of $Cys^{47}$ to serine resulted in a complete loss of the peroxidase activity. This suggests that $Cys^{47}$ acts as a primary site of catalysis. The analysis of the tryptic digest derived from hTSA VI revealed that the $Cys^{47}$ exists as a free thiol form. Taken together, these results suggest that the TSA homologous protein is a new type of the human family, which exerts thioredoxin-linked peroxidase activity toward $H_2O_2$ and alkyl hydroperoxide.

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Characteristics of the Multi-Hydrogen Bonded Systems: DFT Description on the Solvated Electrons

  • Xu, Jun
    • Bulletin of the Korean Chemical Society
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    • 제34권11호
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    • pp.3265-3268
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    • 2013
  • The multi-hydrogen bonded systems with the solvated electrons are investigated at the B3LYP/6-311++$G^{**}$ basis set level. The symmetrical linear geometrical characteristic is common for the dimer systems, while for the tetramer system, the tetrahedron configuration is generated. The NBO charge analyses demonstrate that the multi-hydrogen-multi-electron (mH-ne) coupling exist in these anion systems, as is supported by the electrostatic potential and the molecular orbital analyses. The positive chemical shift value of the central hydrogen ($H_c$) and the negative chemical shift value of the terminal hydrogen ($H_t$) indicate that the $H_c$ is electronegative while the $H_t$ is electropositive, respectively. Strong coupling between two central hydrogen atoms is demonstrated by the large spin-spin coupling constants. The solvated electron donates significant contributions for the stability of these systems.

가상현실환경에서 멀미 측정을 위한 생리신호 분석 (Practical BioSignal analysis for Nausea detection in VR environment)

  • Park, M.J.;Kim, H.T.;Park, K.S.
    • 한국감성과학회:학술대회논문집
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    • 한국감성과학회 2002년도 추계학술대회 논문집
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    • pp.267-268
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    • 2002
  • We developed nausea, caused by disorder of autonomic nervous system, detection system using bio-signal analysis and artificial neural network in virtual reality enironment. We used 16 bio-signals, 9 EEGs, EOG, ECG, SKT, PPG, GSR, RSP, EGC, which has own analysis methods. We estimated nausea level by artificial neural network.

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Analysis of losses within SMES system for compensating output fluctuation of wind power farm

  • Park, S.I.;Kim, J.H.;Le, T.D.;Lee, D.H.;Kim, D.J.;Yoon, Y.S.;Yoon, K.Y.;Kim, H.M.
    • 한국초전도ㆍ저온공학회논문지
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    • 제16권4호
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    • pp.57-61
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    • 2014
  • Output fluctuation which is generated in wind power farm can hinder stability of total power system. The electric energy storage (EES) reduces unstable output, and superconducting magnetic energy storage (SMES) of various EESs has the proper performance for output compensation of wind power farm since it charges and discharges large scale power quickly with high efficiency. However, because of the change of current within SMES, the electromagnetic losses occur in the process of output compensation. In this paper, the thermal effect of the losses that occur in SMES system while compensating in wind power farm is analyzed. The output analysis of wind power farm is processed by numerical analysis, and the losses of SMES system is analyzed by 3D finite element analysis (FEA) simulation tool.

EUROSTAG 조류계산 데이터 편집기 프로그램 개발 (Development of a Data Editor for EUROSTAG Power Flow Calculation)

  • 김종일;김학만;국경수;전영환;오태규;송석하
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 추계학술대회 논문집 학회본부 A
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    • pp.122-124
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    • 2000
  • This study is focused on developing a program which can edit different formats of power system data used by system operators PSS/E program, which has been widely used as a tool for power system analysis. Provides only a limited function of editing PSS/E input data. Considering that more and more power system analysers will be developed and applied for power system planning and operation in the near future, unified handling of multi-types of power system data format, such as conversion of one input data format into another, is indispensible. In this paper, a new power system data editor, functionally augmented from PSS/E editor, is introduced. The new editing program was developed in GUI environment for users to conveniently edit input data for EUROSTAG program without running several editors. Considerable savings in time and manpower are expected.

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