• Journal of applied mathematics & informatics
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• v.15 no.1_2
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• pp.227-235
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• 2004

In this paper we consider the dual problems for multiobjective programming with generalized convex functions. We obtain the weak duality and the strong duality. At last, we give an equivalent relationship between saddle point and efficient solution in multiobjective programming.

• Communications of the Korean Mathematical Society
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• v.20 no.2
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• pp.381-393
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• 2005

We consider a type of large deviation principle obtained by Freidlin and Wentzell for the solution of Stochastic differential equations in a conuclear space. We are using exponential tail estimates and exit probability of a Ito process. The nuclear structure of the state space is also used.

• Journal of the Korean Chemical Society
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• v.57 no.2
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• pp.279-288
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• 2013

In this study, we analyzed the values of ionization and ionization constants in the chemistry textbooks developed during 1945-2009 year. The chemistry teachers compared strength of strong acids in aqueous solution by questionnaire. In the questionnaire, we searched chemistry teachers' cognitions about the discordance reason of ionization constant formulation and the values in the textbooks. The subjects were 46 chemistry teachers. As results, the teachers compared the strength of strong acids in aqueous solution based on the ionization and ionization constant values in the textbooks. They didn't notice the problem of discordance of ionization constant formulation and the values in the textbooks. Even though they recognized the problem, they could not find the solution, and thought the problem arrived by experiment error or measurement error.

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2669-2674
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• 2012

Crown ether is one of well-known host molecules and able to selectively sequester metal cation. We employed M06-2X density functional theory with IEFPCM and SMD continuum solvation models to study selectivity of dibenzo-18-crown-6-ether (DB18C6) for alkaline earth dications, $Ba^{2+}$, $Sr^{2+}$, $Ca^{2+}$, and $Mg^{2+}$ in the gas phase and in aqueous solution. $Mg^{2+}$ showed predominantly strong binding affinity in the gas phase because of strong polarization of CO bonds by cation. In aqueous solution, binding free energy differences became smaller among these dications. However, $Mg^{2+}$ had the best binding, being incompatible with experimental observations in aqueous solution. The enthalpies of the dication exchange reaction between DB18C6 and water cluster molecules were computed as another estimation of selectivity in aqueous solution. These results also demonstrated that $Mg^{2+}$ bound to DB18C6 better than $Ba^{2+}$. We speculated that the species determining selectivity in water could be 2:1 complexes of two DB18C6s and one dication.

• Resources Recycling
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• v.23 no.6
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• pp.63-67
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• 2014

Gallium is an important material and is used by industry of oxide semi-conductor and LED chip. However, the most of the gallium-containing waste resources became outflow abroad and the most of which is imported from oversea by following technical problem and low circulation rate. In this research, the recovery of high purity Gallium metal from Gallium scrap, which containing about 30% of Gallium, was investigated by using hydro-metallurgical process. As pretreatment, the Gallium scrap was pulverized and leached by strong acid such as hydro chloric acid. At the leached solution, Indium was separated as an Indium sponge by substitution reaction and then Gallium and Zinc hydroxide separated and filtrated using strong alkaline solution such as sodium hydroxide by precipitation method. Also, Gallium metal and Zinc metal was recovered by electrowinning method. To make an electrolytic solution, Gallium and Zinc hydroxide was leached by strong alkaline solution. Finally, High purity Gallium metal was recovered by vacuum refining process to remove the Zinc impurity.

• Bulletin of the Korean Chemical Society
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• v.30 no.7
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• pp.1526-1530
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• 2009

Solvent extraction reaction of Zn(II) by Alamine336 from strong HCl solution up to 10 M was identified by analyzing the data reported in the literature. The equilibrium constant of this reaction was estimated by considering the complex formation between zinc and chloride ion. The necessary thermodynamic parameters, such as equilibrium constant for the formation of complexes and the interaction parameters, were evaluated from the thermodynamic data reported in the literature. The following solvent extraction reaction and the equilibrium constant was obtained by considering the activity coefficients of solutes present in the aqueous phase with Bromley equation. $Zn^{2+}\;2Cl^{-}\;+\;R_3NHCl_{org}\;=\;ZnCl_3R_3NH_{org},\;K_{ex}\;=\;6.33\;{\times}\;10^2$ There was a good agreement between measured and calculated distribution coefficients of Zn(II).

• Nonlinear Functional Analysis and Applications
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• v.29 no.1
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• pp.225-258
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• 2024

In this paper, we study the problem of finding a common solution to a fixed point problem involving a finite family of ρ-demimetric operators and a split monotone inclusion problem with monotone and Lipschitz continuous operator in real Hilbert spaces. Motivated by the inertial technique and the Tseng method, a new and efficient iterative method for solving the aforementioned problem is introduced and studied. Also, we establish a strong convergence result of the proposed method under standard and mild conditions.

• Journal of Power System Engineering
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• v.20 no.1
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• pp.42-49
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• 2016

This study showed that on-site ferrate(VI) solution was synthesized by wet oxidation method and applied aqueous 2,4-dichlorophenol(DCP) solution to evaluate the degradation efficiency. On-site ferrate(VI) solution was synthesized by putting $FeCl_3{\cdot}6H_2O$ in the strong alkali solution with NaClO and NaOH and applied DCP solution directly. DCP solution was extracted by the liquid-liquid method and analyzed by GC-ECD. The factors such as pH, DCP initial concentration, injected ferrate(VI) dosage, temperature were investigated. The optimum pH and temperature conditions of DCP degradation were obtained in neutral condition and $35^{\circ}C$. And the experimental results showed that DCP removal efficiency also increased with the decrease of DCP initial condition and the injected ferrate(VI) dosage.

• Transactions of Materials Processing
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• v.13 no.3
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• pp.268-272
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• 2004

Transparent materials such as fused silica are widely utilized in optical and optoelectronics field because of its outstanding properties, such as transparency in a wide wavelength range, strong damage resistance for laser irradiation, and high thermal and chemical stability. In this study, we made a few micro patterns on the surface of fused silica plate using laser induced wet etching. KrF excimer laser was used as a light source. There were no burrs and micro cracks on the etched surface of fused silica and the flatness of the etched surface was fairly good. We investigated the influence of etchant upon the etch rate and quality in laser induced wet etching. Pyrene-acetone solution and toluene were used as etchant. In the side of etch rate, toluene solution was better than pyrene-acetone solution. But we made in wider range of energy density using pyrene-acetone solution. But pyrene-acetone solution gave us wider window of energy density for successful micro patterning.

• Earthquakes and Structures
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• v.10 no.3
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• pp.563-588
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• 2016

In this study, solution models are proposed to obtain code-compatible ground motion record sets which can be used for both uni-directional and bi-directional dynamic analyses. Besides scaled, unscaled ground motion record sets are obtained to show the utility and efficiency of the solution models. For scaled ground motion sets the proposed model is based on hybrid HS-Solver which integrates heuristic harmony search (HS) algorithm with the spreadsheet Solver add-in. For unscaled ground motion sets HS based solution model is proposed. Design spectra defined in Eurocode-8 for different soil types are selected as target spectra. The European Strong Motion Database is used to get ground motion record sets. Also, a sensitivity analysis is conducted to evaluate the effect of different HS solution parameters on the solution accuracy. Results show that the proposed solution models can be regarded as efficient ways to develop scaled and unscaled ground motion sets compatible with code-based design spectra.