• Title/Summary/Keyword: thermodynamic solution

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Determination of Dissociation Constant of Hydrogen Cupferrate in Water, Dioxane-Water, and Ethanol-Water Solution (물, Dioxane-물 및 Ethanol-물의 混合溶媒에서의 Hydrogen Cupferrate의 酸解離常數의 決定)

  • Kim, Si-Joong;Yoon, Chang-Ju;Chang, In-Soon
    • Journal of the Korean Chemical Society
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    • v.10 no.3
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    • pp.114-118
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    • 1966
  • The glass electrode was empirically calibrated in dioxane-and ethanol-water mixed solvents, by means of which the pH-meter reading could be converted to stoichiometric hydrogen ion concentration. By the potentiometric titration method, the thermodynamic dissociation constants of hydrogen cupferrate (HCup) with variations of ionic concentration in aqueous solution were determined, and by the extrapolation of the constants the new thermodynamic $pK_a$ value, 3.980${\pm}$0.006, at zero ional concentration was obtained. The thermodynamic dissociation constants of HCup in dioxane-and ethanol-water solution were also potentiometrically determined with the changes in composition of organic solvents at 0.01 and 0.05 of the ionic strength(${mu}$) and 25 $^{\circ}C$. The empirical formula of the constants with mole fraction(n) of the organic solvent are as follow: Dioxane-water solution. $pK_a$= 12.96n + 4.10 at ${\mu}$ = 0.01, n = 0.0228∼0.171 $pK_a$= 12.05n + 4.23 at ${\mu}$ = 0.05, n= 0.0228∼0.171 Ethanol-water solution, $pK_a$= 4.0ln + 4.26 at ${\mu}$= 0.01, n= 0.0395∼0.262 $pK_a$= 3.83n + 4.34 at ${\mu}$= 0.05, n= 0.0395∼0.262

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An investigation of the thermodynamic effect on the response of FG beam on elastic foundation

  • Bouiadjra, Rabbab Bachir;Bachiri, Attia;Benyoucef, Samir;Fahsi, Bouazza;Bernard, Fabrice
    • Structural Engineering and Mechanics
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    • v.76 no.1
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    • pp.115-127
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    • 2020
  • This study presents an analytical approach to investigate the thermodynamic behavior of functionally graded beam resting on elastic foundations. The formulation is based on a refined deformation theory taking into consideration the stretching effect and the type of elastic foundation. The displacement field used in the present refined theory contains undetermined integral forms and involves only three unknowns to derive. The mechanical characteristics of the beam are assumed to be varied across the thickness according to a simple exponential law distribution. The beam is supposed simply supported and therefore the Navier solution is used to derive analytical solution. Verification examples demonstrate that the developed theory is very accurate in describing the response of FG beams subjected to thermodynamic loading. Numerical results are carried out to show the effects of the thermodynamic loading on the response of FG beams resting on elastic foundation.

Thermodynamic Assessment of the PbO-ZrO2 System

  • Koo, Bon-Keup;Ping Liang;Hans Jiirgen Seifert;Fritz Aldinger
    • The Korean Journal of Ceramics
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    • v.5 no.3
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    • pp.205-210
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    • 1999
  • The thermodynamic properties and phase diagram of the$ PbO-ZrO_2$ system have been critically assessed using the Thermo-Calc program. Excess Gibbs energies were expressed by Redlich-Kister polynomials for the solid phases, by the two-sublattice ionic liquid model for the liquid phase and by the compound energy model for the solid solution phase. All solid phases were treated as stoichimetric compounds.

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Thermodynamic Study of Liquid Pb-Bi, Pb-Na, Bi-Na Binaries and Pb-Bi-Na Ternary Solutions (熔融 Pb-Bi, Pb-Na, Bi-Na 및 Pb-Bi-Na 系의 物理化學的硏究)

  • Koh, Chang-Shik
    • Journal of the Korean Chemical Society
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    • v.6 no.2
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    • pp.133-142
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    • 1962
  • This study was carried out to investigate the lead-bismuth-sodium ternary system which a basis of the Dittmer method as a part of "the fundamental study of pyrometallurgical debismuthizing of lead". Thermodynamic properties of each liquid Pb-Bi, Pb-Na binaries as well as liquid Pb-Bi-Na ternary solution were measured by e.m.f. of these concentration cells, and those of each component were also determined. Furthermore, iso-activity lines including Pb rich side composition of Pb-Bi-Na ternary solution were determined. The relationship between those thermodynamic characteristics and tendency of intermetallic compound formation was discussed through the above experiments.

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Thermodynamic Analysis of an Absorption Heat Pump System with New Working Pairs[I] (1, 2종 흡수식 히트펌프의 작동 매체에 따른 성능 해석[I])

  • Won, S.H.;Lee, W.Y.;Chung, H.S.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.1 no.3
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    • pp.219-227
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    • 1989
  • Performance analysis of an absorption heat pump system for solar energy recovery has been done by computer simulation to find improved working pairs. Based on the thermodynamic analysis, the coefficient of performance and mass flow ratio have been calculated to compare two aqueous solutions [LiCl-water, $LiCi-CaCl_2-Zn(NO_3)_2$-water] which were developed for cooling by others, with the conventional LiBr-water solution. As a result of this analysis, the performances of the new aqueous solutions were found to be better than that of LiBr-water solution not only in cooling systems, but also in heating and in heat transformer systems. Their theoretical thermodynamic performance data were given here with.

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Thermodynamic Analysis of Double-effect Absorption Heat Pump System with New Working Pairs (작동매체에 따른 2중효용 흡수식 시스템의 성능해석)

  • Won, S.H.;Lee, Y.S.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.3 no.4
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    • pp.250-255
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    • 1991
  • Performance analysis of double-effect absorption heat pump system has been done to find improved working pairs (or mixture) by computer simulation. Based on the thermodynamic analysis, the coefficient of performance and mass flow ratio are investigated to compare three aqueous solutions [LiCl-water, LiSCN-LiBr-water, LiCl-$CaCl_2$-$Zn(NO_3)_2$-water] which was developed for only cooling, with conventional LiBr-water solution. It is found that the performances of the new aqueous solutions are better than that of LiBr-water solution not only in cooling systems, but also in heating systems. Theoretical thermodynamic performance data can be used in heat recovery systems by basic design data.

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Thermodynamic Incompatibility of Food Macromolecules (식품 거대분자의 열역학적 비혼합성)

  • 황재관;최문정
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.5
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    • pp.1019-1025
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    • 1998
  • Proteins and polysaccharides are major food macromolecules. Generally, the mixture of these macromolecules can be separated into two phases because of their thermodynamic incompatibility. Phase separ-ation is explained by equilibrium phase diagram, which comprises binodal curve, critical point, phase separation threshold, tie-line and rectilinear diameter. Phase separation of protein-polysacc-haride solution is affected by pH, temperature, ionic strength, molecular weight, molecular structure, etc. Membraneless osmosis has been developed to concentrate protein solutions, using the phase diagram constituted by proteins and polysaccharides. Protein-polysaccharide mixtures are very promising fat mimetics because solution of mixtures forms water-continuous system with two phase-separated gels, which give plastic texture and a fatty mouthfeel.

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Numerical Analysis of the Thermodynamic Stability of Aqueous Cu-Ni-S-H2O System for the Preparation of Thin Copper-Nickel Multi-nano-Layers by Using Pulse Electro-forming

  • Sang Bum, Lee;Yong Choi
    • Journal of the Semiconductor & Display Technology
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    • v.23 no.3
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    • pp.64-68
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    • 2024
  • Thermodynamic solution stability of aqueous copper-nickel-sulfur system was numerically analyzed to produce thin copper-nickel nano-multi-layers by pulse electro-forming. The main program for numerical analysis was written by C# language, which was composed of the data input, numerical calculation, decision and plotting sub-programs. From the thermodynamic data of 32-feasible phases of the Cu-Ni-S-H2O system, the phase stability diagram of the Cu-Ni-S-H2O system was constructed. It revealed the electro-forming condition of the copper and the nickel was VSHE<0.35 for copper deposition, VSHE<-0.24 for nickel deposition, pH=1.0 and 25℃ in the sulfide bath. The coppernickel multi-layers was well produced by electro-forming in the sulfide bath with two-wave pulse voltages of - 0.2VSHE, -0.5 mA/cm2, and 25 seconds for copper deposition and -1.7 VSHE, -50 mA/cm2 and 80 seconds for nickel deposition, at pH=1.0 and 25℃. From TEM and EDX analysis the Cu-Ni multi-layers with about 5 ㎛ thick had the copper-rich phase of about 20 nm in thick and the nickel rich phase of about 25 nm in thick, respectively.

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