• Title/Summary/Keyword: Equilibrium State

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Estimation of Density of Methane and Ethane and Vapor-Liquid Equilibrium Predictions for Methane-Ethane Binary System Using PR and PC-SAFT Equations of State (PR 및 PC-SAFT 상태방정식을 이용한 메탄과 에탄의 기상과 액상의 밀도 추산 및 이성분계의 기-액 상평형 계산)

  • Park, Jong-Kee;Choi, Kun-Hyung;Lee, Sang-Gyu;Yang, Young-Myung;Cho, Jung-Ho
    • Journal of the Korean Institute of Gas
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    • v.14 no.2
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    • pp.22-26
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    • 2010
  • In this study, experimental vapor pressures and densities of vapor and liquid phases versus temperature were estimated using PC-SAFT equation. The estimated results were compared with those using PR equation of state. For the vapor phase densities, both equations well predicted the literature data. However, PC-SAFT equation showed better prediction capability for liquid phase densities. In the comparison of vapor-liquid equilibrium prediction capability for the binary systems of methane and ethane, PC-SAFT equation was better than the PR equation.

Distribution between Air-Soil Concentration of Organochlorine Pesticides (유기염소계 살충제의 대기-토양간 분배)

  • Choi, Min-Kyu;Chun, Man-Young
    • Environmental Analysis Health and Toxicology
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    • v.22 no.4
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    • pp.299-304
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    • 2007
  • This paper was studied to investigate the equilibrium state between organochlorine pesticides (OCPs) concentration of air and soil, and to know whether soil is a secondary pollution source of OCPs in air or not. The OCPs concentration of air ($C_{air}$) and soil ($C_{soil}$) is not related to molecular weight, vapor pressure ($P_L$) and octanol-air partition coefficient ($K_{oa}$). The slope of the regression line between soil-air partition coefficient ($K_{sa}$) and scavenging coefficient ($C_{soil}/C_{air}$) was 0.2952, which the OCPs concentration between air and soil did not reached to the equilibrium state. The soil/air fugacity quotients ($f_{soil}/f_{air}$) of p, p'-DDT/DDD/DDE and ${\beta}-HCH\;(0.30{\sim}0.67$), which is smaller than 1, means the deposit of OCPs from air to soil. However, $f_{soil}/f_{air}$ of heptachlor, heptachlor epoxide, ${\alpha}/{\gamma}-chlordane$, trans-nonachlor, endosulfan sulfate and ${\alpha}/{\gamma}-HCH\;(1.90{\sim}73.25)$, which is greater than 1, means that soil is secondary pollution source of OCPs in air.

Reduction Method of Shoaling of Navigation Channel Using Composite Channel Slope (복단면 항로를 이용한 항로매몰 저감공법)

  • 배기성;김규한;백승화
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.7 no.3
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    • pp.233-240
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    • 1995
  • A large part of shoaling of navigation channel surrounded by fine sand is caused by suspended sediment in non-equilibrium state. We develop a numerical model for predicting shoaling of navigation channel where concentration of suspended sediment in such state is accurately simulated. In this study, effects of channel geometry on the shoaling of the channel are investigated numerically. A composite slope of navigation channel is also proposed to reduce non-equilibrium property of suspended sediment. It is found that the composite slope can effectively reduce non-equilibrium property of suspended sediment and the amount of sediment deposited in the main channel.

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Assessing Bank Competition in Nepal Using Panzar-Rosse Model

  • BUDHATHOKI, Prem Bahadur;RAI, Chandra Kumar;RAI, Arjun
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.11
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    • pp.759-768
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    • 2020
  • The purpose of this study is to assess the state of competition in Nepalese banking over the period from 2010 to 2019. This study employs panel data and a non-structural Panzar-Rosse model to measure the degree of competition in the Nepalese banking industry. The first reduced-form equation is applied to gauge competition, and the second model is used to test the long-run equilibrium in the banking market. The finding reveals that the Nepalese banking market is equilibrium in the long-run. It implies that the factor prices do not affect ROA in the long-run. The result of the H-statistic shows that the Nepalese banking system is operating under the state of perfect competition and is shifted from monopolistic competition to perfect competition. The reduced-form model reveals that the interest income is positive and significantly affected by factor prices. Similarly, the macroeconomic variable GDP growth is positively related to interest income. On the contrary, the bank's specific factors risk and the number of bank branches are inversely associated with the regressand. The outcomes of the study may be advantageous to the policymakers, especially to Nepal Rastra Bank to implement monetary policy and M&A policy for the stability and growth of the financial system of Nepal.

The Influence of the Structural Parameters on the Shape Errors of CRTS Reflector (CRTS 반사판의 구조적 인자가 형상오차에 미치는 영향)

  • 송원근;김승덕
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.16 no.1
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    • pp.87-94
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    • 2003
  • A geometric non-linear finite element formulation of CRTS reflector subjected to displacement loads, corresponding to the successional assembly steps of the reflector, is presented in order to determine the initial static equilibrium state based on the displacement incremental method. Parametric analyses of the influence of cables and mechanical properties of the reflector on the shape error between reference and equilibrium surfaces have been studied. These results of the present study are compared with the others using Galerkin mothod and NASS 98 program to demonstrate the feasibility.

Swelling Behavior and Drug Release of Poly(vinyl alcohol) Hydrogel Cross-Linked with Poly(acrylic acid)

  • Byun, Hong-Sik;Hong, Byung-Pyo;Nam, Sang-Yong;Jung, Sun-Young;Rhim, Ji-Won;Lee, Sang-Bong;Moon, Go-Young
    • Macromolecular Research
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    • v.16 no.3
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    • pp.189-193
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    • 2008
  • Thermal cross-linking method of poly(vinyl alcohol) (PVA) using poly(acrylic acid) (PAA) was carried out on PVA/PAA hydrogels. The level of gelation was measured in the PVA/PAA hydrogels with various PAA contents. The swelling behavior at various pHs showed that the swelling kinetics and water contents of the PVA/PAA hydrogels reached equilibrium after 30 h, and the time to reach the equilibrium state decreased with increasing PAA content in the hydrogel. The water content increased with increasing pH of the buffer solution. The permeation and release of the drug were tested using indomethacin as a model drug. The permeated and released amounts of the drug increased with decreasing the PAA content because of the low free volume in the hydrogel due to the higher cross-linking density. The kinetic profile of drug release at various pHs showed that all samples reached the equilibrium state within the 5 h.

THE ASYMPTOTIC STABILITY BEHAVIOR IN A LOTKA-VOLTERRA TYPE PREDATOR-PREY SYSTEM

  • Ko, Youn-Hee
    • Bulletin of the Korean Mathematical Society
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    • v.43 no.3
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    • pp.575-587
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    • 2006
  • In this paper, we provide 3 detailed and explicit procedure of obtaining some regions of attraction for the positive steady state (assumed to exist) of a well known Lotka-Volterra type predator-prey system. Also we obtain the sufficient conditions to ensure that the positive equilibrium point of a well known Lotka-Volterra type predator-prey system with a single discrete delay is globally asymptotically stable.

THE VARIATIONAL THEORY OF A CIRCULAR ARCH WITH TORSIONAL SPRINGS AT BOTH EDGES

  • Go, Jae-Gwi
    • Journal of the Korean Mathematical Society
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    • v.44 no.3
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    • pp.707-717
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    • 2007
  • Arches are constrained with rotational resistance at both edges. An energy method is used to derive variational formulation which is used to prove the existence of equilibrium states of elastic circular arches for the torsional spring constants ${\rho}-\;{\geq}\;0,\;{\rho}+\;{\geq}\;0,\;and\;{\rho}-\;+\;{\rho}+\;>\;0$. The boundary conditions are searched using the existence of minimum potential energy.

Surface pH Of The Northeastern Pacific Ocean

  • Park, Kilho
    • 한국해양학회지
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    • v.1 no.1_2
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    • pp.1-6
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    • 1966
  • A latitudinal, differential pH distribution is observed in the Northeastern Pacific Ocean with a pH range of 8.15 at high latitude (42 N) to 8.29 at low latitude (23 N). These pH values are generally greater than the calculated equilibrium pH with respect to atmospheric carbon dioxide. If we assume that the calculated equilibrium pH values ae valid, then the surface waters are undersaturated with respect to the atmospheric carbon dioxide during April to June 1966. A high surface pH value of about 8.26 was observed immediately south of the SubarcticBoundary zone near 170 W. This value differs from the equilibration pH by as much as 0.1 unit.

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Supercooled Liquid, Glass and Glass Transition (과냉각 액체, 유리 그리고 유리 전이)

  • Kim, Hack-Jin
    • Journal of the Korean Chemical Society
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    • v.53 no.2
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    • pp.99-110
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    • 2009
  • Characteristics of supercooled liquid and glass, which are the states involved in glass transition, are reviewed. These states are non-equilibrium states, therefore, the glass transition is different from the usual phase transitions. Theories of glass transition and related experimental methods are briefly summarized.