• Title/Summary/Keyword: equilibrium potential

검색결과 456건 처리시간 0.024초

Equilibrium Thermodynamics of Chemical Reaction Coupled with Other Interfacial Reactions Such as Charge Transfer by Electron, Colligative Dissolution and Fine Dispersion: A Focus on Distinction between Chemical and Electrochemical Equilibria

  • Pyun, Su-Il;Lee, Sung-Jai;Kim, Ju-Sik
    • 전기화학회지
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    • 제11권4호
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    • pp.227-241
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    • 2008
  • This article involves a unified treatment of equilibrium thermodynamics of the chemical reaction coupled with other interfacial (phase boundary) reactions. The modified (restrictive) chemical potential ${\mu}_k^+$, such as electrochemical potential, hydrostatic-chemical (mechanochemical) potential (exceptionally in the presence of the pressure difference) and surface-chemical potential, was first introduced under the isothermal and isobaric conditions. This article then enlightened the equilibrium conditions in case where the release of chemical energy is counterbalanced by the supply of electrical energy, by the supply of hydrostatic work (exceptionally in the presence of ${\Delta}p$), and finally by the release of surface energy, respectively, at constant temperature T and pressure p in terms of the modified chemical potential ${\mu}_k^+$. Finally, this paper focussed on the difference between chemical and electrochemical equilibria based upon the fundamentals of the isothermal and isobaric equilibrium conditions described above.

Expansion of the equilibrium constants for the temperature range of 300K to 20,000K

  • Kim, Jae Gang
    • International Journal of Aeronautical and Space Sciences
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    • 제17권4호
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    • pp.455-466
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    • 2016
  • Chemical-kinetic parameters of the equilibrium constants to evaluate the reverse rate coefficients in the shock layer of a blunt body and the expanding flows are derived for the temperature range from 300 K to 20,000 K. The expanded equilibrium constants for the chemical reactions of the dissociation, ionization, associative ionization, and neutral and charge exchange reactions of the atmospheric species and carbon materials are proposed in the present work. In evaluating the equilibrium constants, the inter-nuclear potential energies of the molecular species are calculated by the analytical potential function of the Hulburt-Hirschfelder model, and the parameters of the analytical model are determined from the semi-classically calculated RKR potentials. The electronic states and energies of the atoms are calculated by the electronic energy grouping model, and the rovibrational states and energies of each electronic states of the molecules are evaluated by the WKB method. The expanded equilibrium constants for 31 types of the reactions are provided for the best curve-fit functions, and the recombination reaction rate coefficients evaluated from the present equilibrium constants are compared with existing measured values.

Static behavior of thermally loaded multilayered Magneto-Electro-Elastic beam

  • Vinyas, M.;Kattimani, S.C.
    • Structural Engineering and Mechanics
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    • 제63권4호
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    • pp.481-495
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    • 2017
  • The present article examines the static response of multilayered magneto-electro-elastic (MEE) beam in thermal environment through finite element (FE) methods. On the basis of the minimum total potential energy principle and the coupled constitutive equations of MEE material, the FE equilibrium equations of cantilever MEE beam is derived. Maxwell's equations are considered to establish the relation between electric field and electric potential; magnetic field and magnetic potential. A simple condensation approach is employed to solve the global FE equilibrium equations. Further, numerical evaluations are made to examine the influence of different in-plane and through-thickness temperature distributions on the multiphysics response of MEE beam. A parametric study is performed to evaluate the effect of stacking sequence and different temperature profiles on the direct and derived quantities of MEE beam. It is believed that the results presented in this article serve as a benchmark for accurate design and analysis of the MEE smart structures in thermal applications.

세포막 활동전압에서 음양(陰陽)의 상호관계 (Interrelation of Yin and Yang in Action Potential of Cell Membrane)

  • 박선영;김호현
    • 동의생리병리학회지
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    • 제27권5호
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    • pp.563-569
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    • 2013
  • This study was undertaken to apply the yin-yang theory in action potential. In order to apply the yin-yang theory in action potential, nature of yin and yang, interrelation of yin and yang and action potential in cell were reviewed. According to the yin-yang theory, inner cellular space corresponds to yin, but outer cellular space corresponds to yang. If we classify ions in intracellular fluid or extracellular fluid by nature of yin and yang, potassium(K+) corresponds to yang within yin(陰中之陽), protein(Pr-) corresponds to yin within yin(陰中之陰) in intracellular fluid, and sodium(Na+) corresponds to yang within yang(陽中之陽), chloride(Cl-) corresponds to yin within yang(陽中之陰) in extracellular fluid. Double donnan equilibrium and equilibrium potential were caused by intracellular anion(Pr-) and extracellular cation(Na+) are related with mutual rooting of yin and yang(陰陽互根) and opposition of yin and yang(陰陽對立). The influx and efflux of ion through cell membrane means waxing and waning of yin and yang(陰陽消長), the change of membrane potential means yin-yang conversion(陰陽轉化) during action potential.

경쟁형 전력시장에서 입찰담합의 유인에 대한 분석 기법 연구 (Analysis Technique on Collusive Bidding Incentives in a Competitive Generation Market)

  • 이광호
    • 대한전기학회논문지:전력기술부문A
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    • 제55권6호
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    • pp.259-264
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    • 2006
  • This paper addresses the collusive bidding that functions as a potential obstacle to a fully competitive wholesale electricity market. Cooperative game is formulated and the equation of its Nash Equilibrium (NE) is derived on the basis of the supply function model. Gencos' willingness to selectively collude is expressed through a bargain theory. A Collusion Incentive Index(CII) for representing the willingness is defined through computing the Gencos' profits at NE. In order to keep the market non-cooperative, the market operator has to know the highest potentially collusive combination among the Gencos. Another index, which will be called the Collusion Monitoring Index(CMI), is suggested to detect the highest potential collusion and it is calculated using the marginal cost functions of the Gencos without any computation of NE. The effectiveness of CMI for detecting the highest potential collusion is verified through application on many test market cases.

Sulfur Redox Equilibrium in Mixed Alkali Silicate Glass Melts

  • Kim, Ki-Dong;Hwang, Jong-Hee
    • 한국세라믹학회지
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    • 제48권3호
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    • pp.205-210
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    • 2011
  • The dependence of sulfur redox behavior and its diffusivity on temperature and composition was studied in mixed alkali silicate melts by means of square wave voltammetry (SWV) at different frequencies in a temperature range of $1000^{\circ}C$ to $1400^{\circ}C$. The voltammograms showed two reduction peaks at high frequency but only one peak at low frequency. Irrespective of $K_2O/(Na_2O+K_2O)$, each peak potential due to reduction of $S^{6+}$ to $S^{4+}$ and $S^{4+}$ to $S^0$ moved toward a negative direction with temperature decrease, and the peak current showed a strong dependence on frequency at a constant temperature. However, the compositional dependence of the peak potential showed an inconsistent behavior with an increase of $K_2O$. The mixed alkali effect was not observed in sulfur diffusion. This inconsistency of both peak potential and diffusion for compositional dependence may be derived from the strong volatilization of sulfur in melts.

Game-Theoretic Optimization of Common Control Channel Establishment for Spectrum Efficiency in Cognitive Small Cell Network

  • Jiao Yan
    • International journal of advanced smart convergence
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    • 제13권1호
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    • pp.1-11
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    • 2024
  • Cognitive small cell networks, consisting of macro-cells and small cells, are foreseen as a promising candidate solution to address 5G spectrum scarcity. Recently, many technological issues (such as spectrum sensing, spectrum sharing) related to cognitive small cell networks have been studied, but the common control channel (CCC) establishment problem has been ignored. CCC is an indispensable medium for control message exchange that could have a huge significant on transmitter-receiver handshake, channel access negotiation, topology change, and routing information updates, etc. Therefore, establishing CCC in cognitive small cell networks is a challenging problem. In this paper, we propose a potential game theory-based approach for CCC establishment in cognitive radio networks. We design a utility function and demonstrate that it is an exact potential game with a pure Nash equilibrium. To maintain the common control channel list (CCL), we develop a CCC update algorithm. The simulation results demonstrate that the proposed approach has good convergence. On the other hand, it exhibits good delay and overhead of all networks.

Ortho-to-Para Ratio Studies of Shocked $H_2$ Gas Observed from Two Supernova Remnants IC 443 and HB 21

  • 신종호;이호규;문대식
    • 천문학회보
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    • 제38권1호
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    • pp.48.2-48.2
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    • 2013
  • We present the near-infrared spectra (2.5-5.0 um) of shocked $H_2$ gas, observed with the Infrared Camera onboard the satellite AKARI. Two supernova remnants, IC 443 and HB 21, were observed. IC 443 shows a hint of non-equilibrium ortho-to-para ratio (OPR): 2.4 (-0.2, +0.3). HB 21 also shows an indication of a potential non-equilibrium OPR: 1.8-2.0. These non-equilibrium OPRs are first reported for shocked $H_2$ gas at E(v,J) > 7000 K, as far as we are aware. We concluded that the non-equilibrium OPR probably originates from dissociative J-shocks, considering several factors such as the shock combination requirement, the line ratios, and the possibility that $H_2$ gas can form on grains with a non-equilibrium OPR. The difference in the collision energy of H atoms on grain surfaces would give rise to the observed difference between the OPRs of IC 443 and HB 21, if dissociative J-shocks are responsible for the $H_2$ emission. Our study suggests that shocked-then-cooled $H_2$ gas may play as a heat reservoir with the non-equilibrium OPR.

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분자 동역학 모사를 이용한 액상과 기상 계면에서의 확산계수의 예측 (Estimation of diffusion coefficient at the interface between liquid and vapor phases using the equilibrium molecular dynamics simulation)

  • 김경윤;최영기;권오명;박승호;이준식
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.1584-1589
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    • 2003
  • This work applies the equilibrium molecular dynamics simulation method to study a Lennard-Jones liquid thin film suspended in the vapor and calculates diffusion coefficients by Green-Kubo equation derived from Einstein relationship. As a preliminary test, the diffusion coefficients of the pure argon fluid are calculated by equilibrium molecular dynamics simulation. It is found that the diffusion coefficients increase with decreasing the density and increasing the temperature. When both argon liquid and vapor phases are present, the effects of the system temperature on the diffusion coefficient are investigated. It can be seen that the diffusion coefficient significantly increases with the temperature of the system.

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과학고등학교 학생의 화학 전지에 대한 이해 분석: 분자적 수준의 미시적 관점에서 화학 평형과 연계하여 (Science High School Students' Understandings on Chemical Cells : In Relation to Chemical Equilibrium from the Microscopic Viewpoint at Molecular Level)

  • 김현정;홍훈기
    • 대한화학회지
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    • 제56권6호
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    • pp.731-738
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    • 2012
  • 이 연구의 목적은 과학고등학교 학생들을 대상으로 설문지 조사와 면담을 통해 화학 전지에 대한 개념 이해를 분자적 수준의 미시적 관점에서 화학 평형과 연계하여 분석하는 것이다. 과학고등학교 학생들은 전극을 전해질에 담그자마자 전극의 금속이 산화되는 반응과 금속 이온이 환원되는 반응이 동시에 일어난다는 것과 화학 전지의 화학 평형 상태를 고르는 것에 대한 이해는 높았다. 그러나 전극과 전해질 사이에서 일어나는 상호작용을 미시적 관점으로 이해하는 데는 어려움을 겪고 있어, 화학 전지에서의 전위차 발생, 전자의 흐름, 반쪽 전지의 전위 측정, 산화전극과 환원전극 사이의 전지 전위값 계산하기 등에서는 어려움을 겪었다.