• Transactions of the Korean hydrogen and new energy society
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• v.7 no.2
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• pp.129-135
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• 1996

Voltage-current profiles are measured when hydrogen-oxygen gas is in contact with solid polymer membrane ($Nafion^{(R)}$) as the electrolyte. The feed gas is prepared by mixing hydrogen and oxygen gas in various ratios. The carbon gas diffusion electrodes contacting the electrolyte are treated by platinum catalyst. The platinum surface is impregnated with a 5% $Nafion^{(R)}$ solution to ensure its good surface contact with the electrolyte. The constant voltage between anode and cathode was applied by a DC power supply. The results on the profiles show that the energy efficiency critically depends on the hydrogen concentration in $H_2/O_2$ mixture gas.

• Journal of Electrochemical Science and Technology
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• v.8 no.3
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• pp.257-264
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• 2017

A polymeric ionic liquid, poly(1-methyl 3-(2-acryloyloxypropyl) imidazolium iodide) (PMAPII), was synthesized as a single-iodide-ion-conducting polymer and employed in a gel polymer electrolyte. Gel polymer electrolytes prepared from iodine, 4-tert-butylpyridine, ${\gamma}$-butyrolactone, and PMAPII were applied in quasi-solid-state dye-sensitized solar cells (DSSCs). The addition of 16 wt.% PMAPII provided the most favorable environment, striking a compromise between the iodide ion concentration and the ionic mobility, which resulted in the highest conversion efficiency of the resulting DSSCs. The quasi-solid-state DSSC assembled with the optimized gel polymer electrolyte exhibited a relatively high conversion efficiency of 7.67% under AM 1.5 illumination at $100mA\;cm^{-2}$ and better stability than that of the DSSC with a liquid electrolyte.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.3
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• pp.338-343
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• 2012

Oryeong-san which was first recorded in Shanghanrun describing the treatments of acute febrile disease is one of the frequently used oriental medicines. Oryeong-san has been prescribed for the treatment of symptoms accompanied by edema. The purpose of this study was to examine the diuretic effects of Oryeong-san by different routes of administration. Oryeong-san (100 mg/kg body weight) was administrated by three different routes in Sprague-Dawley rats: intravenous infusion, intraperitoneal injection and oral intake. Oral intake of Oryeong-san significantly increased urinary volume and excretion of $Na^+$, $Cl^-$, and $K^+$ compared to vehicle-treated control group. The effects were concentration-dependent. Intravenously administrated Oryeong-san increased urinary volume and electrolyte excretion but without significance in hydrated (0.02 ml/min/rat for 90 min) anesthetized rats. Similarly, intraperitoneally injected Oryeong-san had no effects on water and urine electrolyte excretion compared with saline control group. These findings suggest that Oryeong-san has different effects on water and electrolyte balance by routes of administration.

• Journal of Electrochemical Science and Technology
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• v.2 no.1
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• pp.8-13
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• 2011

Interfacial compatibility between the Si-Cu electrode and diluted ionic liquid electrolyte containing 50 vol.% of 1M lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)/1-methyl-1-propylpyrrolidinium bis(trifluoromethylsulfonyl)imide (MPP-TFSI) and 50 vol.% dimethyl carbonate (DMC) in a lithium cell and dilution effect on surface chemistry are examined. ex-situ ATR FTIR analysis results reveal that the surface of the Si-Cu electrode cycled in the diluted ionic liquid electrolyte is effectively passivated with the SEI layer mainly composed of carboxylate salts-containing polymeric compounds produced by the decomposition of DMC. Surface species by the decomposition of TFSI anion and MPP cation are found to be relatively in a very low concentration level. Passivation of electrode surface with the SEI species contributes to protect from further interfacial reactions and to preserve the electrode structure over 200 cycles, delivering discharge capacity of > 1670 $mAhg^{-1}$ and capacity retention of 88% of maximum discharge capacity.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.1
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• pp.100-104
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• 2011

In this work, an optimum condition of electrolytes preparation for photovoltaic cells application was investigated experimentally in terms of impedance and conversion efficiency of the cells. 3-methoxyppropionitrie and redox pairs with LiI and $I_2$ were used as stable solvents for fabrication of electrolyte. Efficiency comparison of the prepared cells carried out for various additives and ionic liquids. From the results, there was an optimum concentration (about 0.3 M) of ionic liquids for efficient cell fabrication. For case of electrolyte using single DMAp additive, the maximum conversion efficiency of the cell was 6.4%($V_{oc}$: 0.78V, $J_{sc}$: 14.4 mA/$cm^2$, ff: 0.57). For case of electrolyte using both DMAp and CEMim additives, the maximum conversion efficiency of the cell was 7.2%($V_{oc}$: 0.79V, $J_{sc}$: 16 mA/$cm^2$, ff: 0.57). From the result of electrochemical impedance measurement, both Z1 and Z3 values of binary additives-based cell decreased compared to those of single additive-based. This is due to the decreased in internal and charge transfer resistivities of the cells.

• Journal of Korean Society on Water Environment
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• v.27 no.2
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• pp.194-199
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• 2011

This study has been carried out to evaluate the performance of $PbO_2$ electrode for the purpose of degradation of N,N-Dimethyl-4-nitrosoaniline (RNO, indicator of OH radical), generation of ozone and decolorization of Rhodamine B (RhB) in water. The effect of the applied current (0.2~1.2 A), electrolyte type (NaCl, KCl and $Na_2SO_4$), electrolyte concentration (0.0~2.5 g/L) and solution pH (3~11) were evaluated. Experimental results showed that RhB and RNO removal were increased with the increase of current, NaCl dosage and decrease of pH. Ozone generation tendencies appeared with the almost similar to the RhB and RNO degradation, except of solution pH (Ozone generation was increased with increase of pH). Optimum current for RhB degradation and consumption of electric power was 1.0 A. The RhB degradation with Cl type electrolyte were higher than that with the sulfate type. Optimum NaCl dosage for RhB degradation was 1.0 g/L.

• Journal of the Korean institute of surface engineering
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• v.50 no.5
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• pp.308-314
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• 2017

Anodic film formation behavior of AZ31 Mg alloy was studied as a function of NaOH concentration in 1 M $Na_2CO_3$ + 0.5 M $Na_2SiO_3$ solution under the application of a constant anodic current density, based on the analyses of voltage-time curves, surface appearances and morphologies of the anodically formed PEO (plasma electrolytic oxidation) films. The anodic film formation voltage and its fluctuations became largely lowered with increasing added NaOH concentration in the solution. Two different types of film defects, large size dark spots indented from the original surface and locally extruded white spots, were observed on the PEO-treated surface, depending on the concentration of added NaOH. The large size dark spots appeared only when added NaOH concentration is less than 0.2 M and they seem to result from the local detachments of porous PEO films. The white spots were observed to be very porous and locally extruded and their size became smaller with increasing added NaOH concentration. The white spot defects disappeared completely when more than 0.8 M NaOH is added in the solution. Concludingly it is suggested that the presence of enough concentration of $OH^-$ ions in the carbonate and silicate ion-containing electrolyte can prevent local thickening and/or detachment of the PEO films on the AZ31 Mg alloy surface and lower the PEO film formation voltage less than 70 V.

• Journal of the Korean Electrochemical Society
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• v.13 no.4
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• pp.277-282
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• 2010

Durability of automotive polymer electrolyte membrane fuel cell (PEMFC) strongly depends the startup/shutdown procedure. Formation of hydrogen/air boundary in the anode gas channel, so-called reverse current condition, particularly induces fast degradation of the cathode. Under the reverse current condition, high voltage is present at the cathode facing air in the anode gas channel and is a function of residual oxygen concentration in the gas channels, that increases with storage time and reaches 21% (air) eventually. In this study, effects of residual oxygen concentration in a PEMFC on degradation of the PEMFC.

• Journal of Korean Society on Water Environment
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• v.26 no.6
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• pp.963-968
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• 2010

This study has carried out to evaluate the performance of direct and indirect oxidation electrode for the purpose of decolorization of Rhodamine B (RhB) in water. Four kinds of electrodes were used for comparison: Pt and JP202 (indirect oxidation electrode), Pb and boron doping diamond (BDD, direct oxidation electrode). The effect of applied current (0.5 ~ 2.5 A), electrolyte type (NaCl, KCl, HCl, $Na_2SO_4$ and $H_2SO_4$) and electrolyte concentration (0.5 ~ 2.5 g/L), solution pH (3 ~ 11) and initial RhB concentration (25 ~ 125 mg/L) were evaluated. Experimental results showed that RhB removal efficiency were increased with increase of current, NaCl dosage and decrease of the pH. However, the effect of operating parameter on the RhB removal were different with the electrode type. JP202 electrode was the best electrode from the point of view of performance and energy consumption. The order of removed RhB concentration per energy lie in: JP202>Pt>Pb>BDD.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2529-2535
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• 2013

Sol-gel method was utilized to prepare SPEEK/PWA electrolyte composite membranes. TEOS was used as a precursor and phosphotungstic acid(PWA) as a catalyst for the sol-gel reaction. It was observed through FE-SEM analysis that the PWA and silica nanoparticles were uniformly dispersed into the polymer matrix. The water uptake of SPEEK/PWA/silica composite membranes was less affected by TEOS concentration at higher TEOS contents, while the water uptake decreased as TEOS concentration increased at lower TEOS contents. The proton conductivity of the composite membranes showed similar trend as the water uptake of the composite membranes. The methanol permeability of SPEEK/PWA/silica composite membranes decreased as TEOS concentration increased.