• Bulletin of the Korean Chemical Society
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• v.27 no.4
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• pp.539-544
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• 2006

Proton transfer reactions and ion-molecule reactions of bifunctional ethanes of $H_2NCH_2CH_2NH_2$, $H_2NCH_2CH_2OH$, and $HOCH_2CH_2OH$ were studied using Fourier transform mass spectrometry (FTMS). The rate constants for proton transfer reactions between the fragment ions and neutral molecules were obtained from the temporal variation of the ion abundances. The rate constants were consistent with the heats of reaction. The fastest proton transfer reactions were the reactions of $CH_2N^+$, $CHO^+$, and $CH_3O^+$ for $H_2NCH_2CH_2NH_2$, $H_2NCH_2CH_2OH$, and $HOCH_2CH_2OH$, respectively. The $[M+13]^+$ ion was formed by the ion-molecule reaction between $H_2C=NH_2 ^+$ or $H_2C=OH^+$ and the neutral molecule. The major product ions generated from the ion-molecule reactions between the protonated molecule and neutral molecule were $[2M+H]^+$, $[M+27]^+$, and $[M+15]^+$.

• Journal of Mechanical Science and Technology
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• v.20 no.12
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• pp.2197-2202
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• 2006

The steady hydromagnetic flow due to a rotating disk is studied with heat transfer considering the ion slip. The governing equations are solved numerically using finite differences. The results show that the inclusion of the ion slip has important effects on the velocity distribution as well as the heat transfer.

• Analytical Science and Technology
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• v.8 no.4
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• pp.481-486
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• 1995

Quenching experiments by photoinduced electron transfer between a charged donor and a neutral acceptor were carried out in acetonitrile, dichloromethane and mixed solvents of acetonitrile and dichloromethane. Tris(2, 2'-bipyridine) ruthenium(II) ($[Ru(bpy)_3]^{2+}$) which has 2+ charge and dicyanobis (2, 2'-bipyridine) ruthenium(II) ($Ru(bpy)_2(CN)_2$) which has no charge were used as electron donors, and a series of tris(${\beta}$-diketonato) ruthenium (III) was used as acceptor. In dichloromethane, $[Ru(bpy)_3]^{2+}$ and its counter ions ($ClO{_4}^-$) form ion pair. In the estimate of ${\Delta}G$ of electron transfer, the electrostatic potential between counter ions and product ion pair produced by electron transfer must be taken into account. A similar effect of counter ions was found in mixed solvents of 10, 30, 50, 70 and 90% acetonitrile ratio in volume. The effect of counter ion on ${\Delta}G$ became smaller with the increase in acetonitrile ratio. The result in mixed solvents suggests that $[Ru(bpy)_3]^{2+}$ and its counter ions form ion pair even in 90% acetonitrile solution.

• Bulletin of the Korean Chemical Society
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• v.20 no.10
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• pp.1181-1185
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• 1999

The reaction of FeC5H5+ ion with ferrocene molecule is investigated using FT-ICR mass spectrometry. FeC5H5+ ions are generated by dissociative ionization of ferrocenes using an electron beam. The reaction gives rise to the formation of the adduct ion, Fe2(C5H5)3+, in competition with charge transfer reaction leading to the formation of ferrocene molecular ion, Fe(C5H5)2+·. The branching ratio of the adduct ion increases as the internal energy of the reactant ion decreases and correspondingly the branching ratio for the charge transfer reaction product decreases. The observed rate of the addition reaction channel is slower than that of the charge transfer reaction. The observation of the stable adduct ions in the low-pressure ICR cell is attributed to the radiative cooling of the activated ion-molecule complex. The mechanism of the reaction is presented to account for the observed experimental results.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.11
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• pp.1022-1027
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• 2005

An experimental study is conducted to investigate the characteristics of the ion wind generated by the electric field between a needle electrode and the parallel plate electrodes. The ion wind enhances heat and mass transfer between the surface and the surrounding gas. Moreover such enhancement makes no noise or vibration. This study is conducted to develop the electronic cooling device. The measured gas velocities and heat transfer coefficients are proportional to the applied voltage. The heat transfer coefficient can be increased as compared with a natural convection. The maximum enhancement of heat transfer obtained in this system is $47\%$ for 3 W in heat transfer rate.

• Analytical Science and Technology
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• v.8 no.4
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• pp.597-601
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• 1995

The transfer of chloride ion across an anion exchange membrane (AEM) was investigated by cyclic voltammetry (CV) and electrochemical impedance spectra. In CV experiment, when the size of the hole in membrane was much smaller than the distance between membrane holes, the Cl anion transfer showed steady state voltammetric behavior. Each hole in membrane can be regarded as a microelectrode and the membrane was equivalent to a microelectrode array in this condition. When the hole in membrane was large or the distance between membrane holes was small, the CV curve of the Cl anion transfer across membrane showed peak shape, which attributed to linear diffusion. In ac impedance measurement, the impedance spectrum of the membrane system was composed of two semicircles at low de bias, corresponding to the bulk characteristics of the membrane and the kinetic process of ion transfer, respectively. The bulk membrane resistance increases with increasing dc bias and only one semicircle was observed at higher dc bias. The parameters related to kinetic and membrane properties were discussed.

• Nuclear Engineering and Technology
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• v.51 no.1
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• pp.84-94
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• 2019

Aluminum substrates are irradiated with chromium ions and the steam condensation heat transfer performance on these surfaces is examined. Filmwise condensation is induced on the surface of aluminum specimens irradiated with chromium ion dose of less than $10^{16}ions/cm^2$ while dropwise condensation occurs on the specimens irradiated with chromium ion dose of $5{\times}10^{16}ions/cm^2$ in the range of ion energy from 70 to 100 keV. The heat transfer coefficient of the surfaces on which dropwise condensation occurs appeared to be approximately twice as much as the prediction by Nusselt's film theory. In a durability test, dropwise condensation lasts over six months and the heat transfer coefficient is also maintained.

• Bulletin of the Korean Chemical Society
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• v.25 no.10
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• pp.1538-1544
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• 2004

Fragmentations and proton transfer reactions of mono-, di-, and triethanolamines were studied using FTMS. It was found that the most abundant fragment ion was $[M-CH_2OH]^+$. The $[M-CH_2OH-H_2O]^+$ was observed in the mass spectra of diethanolamine and triethanolamine. By increasing the ion trapping time in the ICR cell, the $[M+H]^+$ and $[M+H-H_2O]^+$ ions were notably increased for all the samples while the $[M+H-2H_2O]^+$ was observed in the mass spectra of diethanolamine and triethanolamine. The proton transfer reactions between the fragment ions and neutral molecules occurred predominantly by increasing the ion trapping time. The rate constants for the proton transfer reactions were calculated from experimental results. The proton transfer reaction of $CHO^+$ was the fastest one, which is consistent with the heats of reaction. The rate constants for proton transfer reactions of triethanolamine were much slower than those of ethanolamine and diethanolamine because of the steric hindered structure of triethanolamine. The plausible structures of observed ions and heats of reaction for proton transfer were calculated with AM1 semiempirical method.

• Journal of Photoscience
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• v.3 no.3
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• pp.147-151
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• 1996

Dynamics of contact ion-pair between 1, 2, 4, 5-tetracyanobenzene anion and cation of biphenyl derivatives was investigated on the picosecond time scale. Solvent effect on the electron transfer was observed and electron transfer rates were examined using Marcus equation which contains distance dependence of the electron transfer rate in the frequency factor, along with the consideration of molecular shape. From the discussion based on disk model for molecular shape, contribution of interring torsional motion of biphenyl to the inner-sphere reorganization energy is strongly suggested, which leads to the physical explanation for the observed solvent effect on the rate of electron transfer.

• Applied Chemistry for Engineering
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• v.24 no.5
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• pp.443-455
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• 2013

Electrochemical studies on charge transfer reactions across the interface between two immiscible electrolyte solutions (ITIES) have greatly attracted researcher's attentions due to their wide applicability in research fields such as ion sensing and biosensing, modeling of biomembranes, pharmacokinetics, phase-transfer catalysis, fuel generation and solar energy conversion. In particular, there have been extensive efforts made on developing sensing platforms for ionic species and biomolecules via gelifying one of the liquid phases to improve mechanical stability in addition to creating microscale interfaces to reduce ohmic loss. In this review, we will mainly discuss on the basic principles, applications and future aspects of various sensing platforms utilizing ion transfer reactions across the ITIES. The ITIES is classified into four types : (i) a conventional liquid/liquid interface, (ii) a micropipette supported liquid/liquid interface, (iii) a single microhole or an array of microholes supported liquid/ liquid interface on a thin polymer film, and (iv) a microhole array liquid/liquid interface on a silicon membrane. Research efforts on developing ion selective sensors for water pollutants as well as biomolecule sensors will be highlighted based on the use of direct and assisted ion transfer reactions across these different ITIES configurations.