• Title/Summary/Keyword: Thermodynamic Method

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Thermodynamic Evaluation of Fe Effect on Alumina Solubility in Orthopyroxene coexisting with Garnet

  • Lee, Han-Yeang
    • Journal of the Korean earth science society
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    • v.25 no.1
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    • pp.39-47
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    • 2004
  • In the FMAS system the effect of iron on alumina solubility in orthopyroxene has been determined by experiments with crystalline starting mixtures of garnet and orthopyroxene of known initial compositions at 20 kb, 975$^{\circ}C$ and 25 kb, 1,200$^{\circ}C$. These data have been modeled to develop a thermodynamic method for the calculation of Al$_{2}$O$_{3}$ in orthopyroxene as a function of P, T and composition. The direct application of the alumina solubility data in the MAS system to natural assemblages could lead to significant overestimation of pressure, probably by about 5kb for the relatively common garnet-lherzolites with abot 25 mol per cent Ca + Fe$^{2+}$ in garnet and about 1 wt. per cent Al$_{2}$O$_{3}$ in orthopyroxene since the effect of Fe is similar to that of Ca and Cr$^{3+}$in reducing the alumina solubility in orthopyroxene in equilibrum with garnet relative to that in the MAS system.

Calculations of Solubility Preduct Constants for Metal Oxides in the KCI-LiCl Eutectic Composition by Exact Thermodynamic Cycle (KCl-LiCl 공정 용융염욕에서 열역학적 싸이클법에 의한 금속산화물의 용해도적 계산)

  • 백영현
    • Journal of the Korean institute of surface engineering
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    • v.23 no.4
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    • pp.225-229
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    • 1990
  • Solubility Products of metal oxides, such as Al2O3 and UO2 in KCl-LiCl eutectic composition was calculated by using an exact an exact thermodynamic. The values for Al2O3 ThO2 and UO2 were found to be 2.51$\times$10-27, 4.97$\times$10-15and 2.17$\times$10-12in mole per liter basis at 743 K, respectively. The correlation of theoretical values with those of experiment were in good agreement. It is worth to note that the exact cycle method was proved to be satisfactory in making predictions of solubillities and also solubility products of sparingly soluble metal oxides in an ionic salt system.

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Spectroscopic investigations on the interaction of bovine serum albumin with amoxicillin and cloxacillin

  • BHALCHANDRA P. KAMAT,
    • Journal of Photoscience
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    • v.12 no.1
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    • pp.11-15
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    • 2005
  • The mechanism of interaction of two drugs viz., amoxicillin and cloxacillin with bovine serum albumin has been investigated using fluorescence absorption and circular dichroism spectroscopy. The quenching mechanism of fluorescence of bovine serum albumin by amoxicillin and cloxacillin was discussed. The binding sites number n and apparent binding constant Kwere measured by fluorescence quenching method. The thermodynamic parameters obtained from data at different temperatures were calculated. The distance r between donor (bovine serum albumin) and acceptor (amoxicillin and cloxacillin) was obtained according to Forster theory of non-radiative energy transfer. The effect of common ions on binding constant was also investigated. The results of synchronous fluorescence spectra, UV-vis absorption spectra and circular dichroism of BSA in presence of amoxicillin and cloxacillin show that the conformation of bovine serum albumin changed

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The Theory of Significant Structure of Liquids : A New Method of Fixing Parameters (액체의 구조에 관하여 -새로운 Parameter 결정법-)

  • Hyungsuk Park;Seihun Chang
    • Journal of the Korean Chemical Society
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    • v.7 no.2
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    • pp.174-178
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    • 1963
  • The new method to determine the parameters in the liquid partition function of H. Eyring and co-workers is proposed, in which method the equilibrium condition of the three phases and the boundary condition of the liquid partition function at the triple point are used. The calculated thermodynamic properties using the new determined parameters are agreed well with the observed values.

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Variations of Turbulent Fluxes in the Atmospheric Surface Layer According to the Presence of Cloud (구름 유무에 따른 대기표층 난류속의 변화)

  • de Oliveira Junior, Jose Francisco;Kwon, Byung-Hyuk
    • Journal of the Korean earth science society
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    • v.25 no.2
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    • pp.87-93
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    • 2004
  • To study the effect of cloud on the variabilities of turbulent fluxes over the flat terrain, we used the gradient method to analyze the dynamic and thermodynamic data from the meteorological 9-m mast (0.75, 3 and 9 m) in Villafria airport in Spain. The decrease of the surface wind speed is governed by cooling at the surface following the evening transition. The sensible heat flux and the momentum flux are increased with the dynamic factor rather than the thermodynamic factor, and the sensible heat flux was not affected by the thermal condition. The global radiation did not play an important role in the variation of the sensible heat flux in the cloudy day, but the atmospheric surface layer was characterized rather by the wind intensity.

Performance analysis of a hermetic reciprocating compressor using the alternative refrigerants, HFC134a and HC600a (대체냉매(HFC134a, HC600a)용 밀폐형 왕복동 압축기의 성능해석에 관한 연구)

  • Kim, Jeong-U
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.22 no.7
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    • pp.966-979
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    • 1998
  • Thermodynamic and dynamic analysis has been conducted to investigate performance variations induced by substitution of alternative refrigerants, HFC134a or HC600a for CFC12 in hermetic reciprocating compressors. For the thermodynamic analysis, mass and energy conservation laws are applied to the cylinder volume and Helmholtz resonator modeling method is adopted to describe gas pulsations at suction and discharge system. The modeling of the dynamics of the compressor mechanism has been performed with lumped mass method to analyse the bearing loads and friction losses at each bearing. To verify the correctness of this analysis, results of the performance simulation have been compared to those of calorimetric measurrements of compressor operating with CFC12. Analysis of the various losses, noise and reliability as well as performance has been conducted to present the design guideline for the compressor development with alternative refrigerants. It is found that compressors with alternative refrigerants, HFC 134a or HC600a give better COPs than those with CFC12 under the same operating conditions and especially, compressors with HC600a show better reliability and noise characteristics also.

Sensitivity Study of Simulated Sea-Ice Concentration and Thickness Using a Global Sea-Ice Model (CICE) (전구 해빙모델(CICE)을 이용한 해빙 농도와 해빙 두께 민감도 비교)

  • Lee, Su-Bong;Ahn, Joong-Bae
    • Atmosphere
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    • v.24 no.4
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    • pp.555-563
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    • 2014
  • The impacts of dynamic and thermodynamic schemes used in the Community Ice CodE (CICE), the Los Alamos sea ice model, on sea ice concentration, extent and thickness over the Arctic and Antarctic regions are evaluated. Using the six dynamic and thermodynamic schemes such as sea ice strength scheme, conductivity scheme, albedo type, advection scheme, shortwave radiation method, and sea ice thickness distribution approximation, the sensitivity experiments are conducted. It is compared with a control experiment, which is based on the fixed atmospheric and oceanic forcing. For sea ice concentration and extent, it is found that there are remarkable differences between each sensitivity experiment and the control run over the Arctic and Antarctic especially in summer. In contrast, there are little seasonal variations between the experiments for sea ice thickness. In summer, the change of the albedo type has the biggest influence on the Arctic sea ice concentration, and the Antarctic sea ice concentration has a greater sensitivity to not only the albedo type but also advection scheme. The Arctic sea ice thickness is significantly affected by the albedo type and shortwave radiation method, while the Antarctic sea ice thickness is more sensitive to sea ice strength scheme and advection scheme.

Substitutional Adsorption and Thermodynamic Characteristics of Proton and Di-iso-butylnitrosoamine in NaCl Aqueous Solution (NaCl 수용액내의 양성자와 디이소부틸니트로소아민의 치환흡착과 열역학적 특성)

  • HWANG Kum-Sho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.16 no.3
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    • pp.239-245
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    • 1983
  • Electrochemical adsorption always was accompanied with solvent displacement and relative size factor(x) of adsorbate and solvent and hydrogen coverage(${\theta}$) on the lead anodic film electrode formed in phosphoric acid in NaCl solution and the sea water at $15{\sim}35^{\circ}C$ were studied by means of constant current-potential method and potentiodynamic cathodic polarization method. In this experiment, various constants and thermodynamic quantities calculated from the hydrogen coverage were also described to explain the reactivities of di-iso-butylnitrosoamine(DBNA) and proton ($H^+$) according to the changes of interactions between solute and solvent in the bulk phase and interphase. It was investigated that the average values of relative size factor and the coverage of hydrogen atoms studied with the electrode of lead anodic film formed in phosphoric acid solution in 60mM DBNA+0.5M NaCl and in 60mM DBNA+$6\%0$ sea water were about 11.0 and 0.2 respectively. Hydrogen evolution was electrochemical mechanism because of substitutional adsorption of aromatic substance with their delocalization of electrons, but in the case of non-charge transfer adsorption of aliphatic substance(DBNA) interacting relatively little with the electrode, it was combination mechanism.

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