• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.7
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• pp.1152-1157
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• 1994

The glasses were prpared in the system CuI-CuS12TS-CuS12TO-MoOS13T by rapid quenching technique. These glasses have high ionic conductivities at 2$0^{\circ}C$ in the range of 10S0-1T[S/m], and the conductivities increase with increasing CuI and CuS12TS content. The value of activation energy for dielectric relaxation is nearly identical with that for conductivity. The cole-Cole parameter $\beta$ for representation of the distribution of dielectric relaxation times varies the range from 0.92 to 0.96. This parameter has a weak dependence on the composition of glass, and is independent of temperature. The correlation factors P for the glasses shows from 1.1 to 1.7.

• Korean Chemical Engineering Research
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• v.43 no.2
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• pp.266-271
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• 2005

This paper studied succinic acid recovery from organic acid mixture by using mono-polar membrane electrodialysis. Current efficiency, solute recovery efficiency, energy consumption, and separation factor were measured at various pHs and concentration ratios. The separation factor of succinic acid could be interpreted in terms of ionization degree, molecular weight, ionic conductance, average charge, and initial feed composition.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.4
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• pp.349-355
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• 2002

The ionic conductivity of cubic solid solutions in the systems of CaO-$ZrO_2$, $Y_2O_3-ZrO_2$ prepared by SHS was examined. The higher conductivity appears to be related to a lower activation energy rather than to the number of oxygen vacancies dictated by composition. Conductivity-temperature data was obtained at 1000 $^{\circ}C$ in atmosphere of low oxygen partial pressure (~$10^{-40}$ atm) for $Y_2O_3-ZrO_2$ cubic solid solutions. The data indicated that these materials could be reduced, and the decree of reduction would be related with the measuring electric field.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.47-48
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• 2001

It is well known that atmospheric aerosols play an important role in the radiation balance of the earth and meteorological processes as well as in atmospheric chemistry. Aerosols may origin from both natural and/or anthropogenic sources. Thus, the chemical composition of aerosols can vary considerably. For example, the chemical composition of marine aerosol has been the subject of a considerable number of investigations, including the evaluation of long-range transport of anthropogenic constituents on the chemistry of the remote marine boundary layer. (omitted)

• Journal of the Korean Electrochemical Society
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• v.18 no.1
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• pp.1-6
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• 2015

In this study polystyrene derivative, VBCE, having a cyclic carbonate was synthesized by Williamson reaction and polymerized to poly(VBCE) successfully in an usual polymerization conditions. The obtained polymer was blended with PEGMA and the effect of composition on the ionic conductivity was investigated. Interestingly, the ionic conductivity was decreased from $4.2{\times}10^{-5}S\;cm^{-1}$ to $3.93{\times}10^{-6}S\;cm^{-1}$ with the poly(VBCE) contents of 5.8mol%. From the DSC study, it was found that the $T_g$ of the blend was increased from $-50^{\circ}C$ to $-21^{\circ}C$ by the addition of poly(VBCE). Therefore, it is believed that the presence of a polar cyclic carbonate makes polymer matrix harder and it is necessary to design new structures less hindered the mobility of the matrix.

• Analytical Science and Technology
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• v.16 no.2
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• pp.159-165
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• 2003

To develop an ionic equilibria model applicable to the sulfuric acid leaching solutions of zinc oxide ore, the method of the Pitzer equation and that of the Vasil'ev equation were compared. As the ionic strength of the solution increased to 9 m, the results of ionic equilibria by the Pitzer equation were more accurate than those by Vasil'ev. To simulate the sulfuric acid leaching solutions of zinc oxide ore, the mixed solutions with the various composition of $ZnSO_4-Fe_2(SO_4)_3-Na_2SO_4-H_2SO_4-NaOH-H_2O$ were prepared. The pH values calculated in this study agreed well with those measured at $25^{\circ}C$.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.E4
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• pp.177-186
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• 2003

The total of 1,454 aerosol samples were collected by high volume tape sampler at the Gosan Site in Jeju Island from 1992 to 1999, and the major water-soluble ionic components were chemically analyzed. The mean concentrations of nss-S $O_4$$^{2-}$, N $H_4$$^{＋}$, and N $O_3$$^{[-10]}$ showed high values, which were 6.73, 1.45, and 1.45 ${\mu}{\textrm}{m}$/㎥, respectively, while $Ca^{2+}$ and $K^{+}$ concentrations were low with the values of 0.49 and 0.42 $\mu\textrm{g}$/㎥. The concentrations of most components increased in spring but decreased in summer, especially with the remarkable increase of $Ca^{2+}$ and N $O_3$$^{[-10]}$ concentrations in spring. The seasonal comparison of nss-S $O_4$$^{2-}$ concentrations showed higher values with the order of spring > fall 〉 winter〉 summer, but spring 〉 winter〉 fall 〉 summer for N $O_3$$^{[-10]}$ Meanwhile, the concentration levels of N $a^{+}$ and C $l^{[-10]}$ increased more in winter season. According to the investigation of wind direction effect, the concentrations of most aerosol ionic components showed higher values consistently at the westerly and northerly wind conditions. Based on the factor analysis, the atmospheric aerosols in the Gosan Site are considered to be largely affected by marine sources, followed by anthropogenic and soil sources.urces..

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.6
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• pp.723-733
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• 2011

The ionic compositions were analyzed from the TSP samples collected at Gosan site in Jeju Island between 2000 and 2008, in order to examine the characteristics of atmospheric aerosols in accordance with the meteorological conditions. For the Asian Dust influence on the ionic compositions, the concentration ratios of $NH_4{^+}$, nss-${SO_4}^{2-}$, $NO_3{^-}$, and $K^+$ were about 1.2~2.3 during Asian Dust over Non-Asian Dust periods, noticeably that of nss-$Ca^{2+}$ was 6.8. Meanwhile the concentrations of nss-${SO_4}^{2-}$, $NO_3{^-}$, and $NH_4{^+}$ have increased as 1.8~4.4 times during the haze event periods, and 1.0~1.6 times during the fog and mist events. The ion balance has resulted that the anionic concentrations are relatively lower than the cationic concentrations, and the discrepancy appears more decidedly as a strong Asian Dust effect. The ammonium ion balance has shown that it exists as a mixture of $NH_4HSO_4$ and $(NH_4)_2SO_4$. The concentration ratios of nss-${SO_4}^{2-}/NO_3{^-}$ for Asian Dust, haze, fog-mist, and non-event periods were respectively 1.8, 5.9, 4.6, and 2.9, which were higher values compared to those in urban areas of China as well as other domestic regions. Especially, the high ratios of sulfur oxides could be presumed by the fact that the longrange transport of air pollutants from Asia continent might affect the atmospheric aerosols of Jeju Island.

• Composites Research
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• v.28 no.6
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• pp.383-388
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• 2015

Ionic Polymer-Metal Composite (IPMC) consisting of soft membrane plated by platinum electrode layers on both surfaces generates electric energy when subjected to various mechanical stimuli. The paper proposes a circuit model that describes the physical composition of IPMC to predict the voltage generation characteristic corresponding to bending motion. The parameter values in the model are identified to minimize the RMS error between the real and simulated outputs. Following the design of IPMC circuit model, the state observer of the model is designed by using pole placement technique which improves the model accuracy. State observer design technique is also applied to find the inverse model which estimates the input bending angles from the output voltage data. The results show that the inverse model estimates input bending angles fairly well enough for the further applications of IPMC not only as an energy harvester but also as a bending sensor.

• Analytical Science and Technology
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• v.24 no.1
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• pp.24-37
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• 2011

The ionic compositions of atmospheric aerosols were investigated and characterized in coastal and mountainous sites of Jeju Island, which were Gosan and Mt. Halla-1100 sites respectively. It was found that the concentrations of nss-$SO_4^{2-}$ (non-sea salt sulfate) and $NH_4^+$ at two measurement sites were almost similar and they showed high concentrations in June at the same time. The concentration of soil-originated nss-$Ca^{2+}$ (non-sea salt calcium) was generally associated with that of anthropogenic $NO_3^-$ and its concentration was increased during spring season. From the comparison of time-series variation and regression analysis of ionic species between two measurement sites, TSP (total suspended particulate) in Gosan site was directly influenced by sea salt particles and the concentration levels of nss-$SO_4^{2-}$, $NH_4^+$, nss-$Ca^{2+}$, $K^+$, and $NO_3^-$ were mainly related with long-range transported air pollutants rather than local pollution sources.