• Journal of Animal Science and Technology
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• v.48 no.2
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• pp.315-324
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• 2006

This research was conducted to clarify the characteristics of electrochemical decolorization of effluent discharged from a biological animal wastewater treatment process and to finally establish parameters or mode for optimum operation of electrolysis system. Average color unit of wastewater was about 1,200 and DSA(Dimensionally Stable Anode) was used as electrode. Experiments were performed with two different operation conditions or modes, fixed voltage-free current(Run A) and free voltage-fixed current(Run B). Color removal rate was proportional to the electrode area and electrical conductivity, and an equation subject to them at a condition of fixed voltage was derived as follows; Ct=C0ekt, k=[{0.0121×ａ(dm2)× c(mS/cm)}+0.0288], [where, C0: initial color, Ct: color unit after treatment for t, k: reaction coefficient, t: time(min.), ａ: electrode area, c: conductivity]. From the study on the effects of current density on color removal, it was revealed that the removal efficiency of color was function of the current density, showing direct proportion. However, when considered energy consumption rate, maintenance of low current density was an economical way. Based on the obtained results, it was concluded that supplementation of electrolyte is not necessary for the removal of color from the effluent of secondary treatment process and operation with the mode of free voltage-fixed current, rather than operation with fixed voltage-free current mode, would be an efficient way to increase the removal performance and capacity per consumed energy.

• Proceedings of the Safety Management and Science Conference
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• 1999.11a
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• pp.543-563
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• 1999

For hazardous air pollutants(HAP) such as NO and $NO_2$ decomposition efficiency, power consumption, and applied voltage were investigated by SPCP(surface induced discharge plasma chemical processing) reactor to obtain optimum process variables and maximum decomposition efficiencies. Decomposition efficiency of HAP with various electric frequencies(5~50 kHz), flow rates(100~1,000 mL/min) initial concentrations(100~1,000 ppm), electrode materials(W, Cu, Al), electrode thickness(1, 2, 3 mm) and number of electrode windings(7, 9, 11) were measured. Experimental results showed that for the frequency of 10 kHz, the highest decomposition efficiency of 94.3% for NO and 84.7% for $NO_2$ were observed at the poser consumptions of 19.8 and 29W respectively and that decomposition efficiency decreased with increasing frequency above 20 kHz. Decomposition efficiency was increased with increasing residence times and with decreasing initial concentration of pollutants. Decomposition efficiency was increased with increasing thickness of discharge electrode and the highest decomposition efficiency was obtained for the electrode diameter of 3mm in this experiment. As the electrode material, decomposition efficiency was in order : tungsten(W), copper(Cu), aluminum(Al).

• Nuclear Engineering and Technology
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• v.26 no.3
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• pp.425-432
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• 1994

Voltammogram analysis of U(VI) reduction at electrochemically non-pretreated/pretreated Ti electrodes in nitric acid and hydrazine($N_2$H$_4$)/protonated hydrazine($N_2$H$_{5}$$^{＋}$) media was done in order to determine the effect of hydrazine form and Ti electrode condition on the reduction of U(VI) in nitric acid. In the case of non-pretreated Ti electrode, the reduction in nitric acid and hydrazine mono-hydrate solution needed a high activation overpotential and was affected by the ratio of hydrazine to nitric acid rather than by only absolute amount of hydrazine because of the decrease of solution conductivity and increase of iR drop, which were caused by proton consumption in the solution by the hydrazine. In the case of pretreated Ti electrode in nitric acid and protonated hydrazine solution, the reduction current peaks of U(VI) were clearer and higher enough to perform a kinetic analysis, compared with the case with the non-pretreated Ti electrode at the same potential, and the behavior was strongly affected by nitric acid. The presence of hydrazine was important in the reduction of U(VI) at the pretreated Ti electrode for preventing the reoxidation of U(IV), but the concentration of protonated hydrazine was not.t.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.5
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• pp.735-742
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• 2010

Biogenic amines are synthesized by microbial decarboxylation for the putrefaction or fermentation of foods containing protein. Although biogenic amines such as histamine, tyramine, and putrescine are required for many physiological functions in humans and animals, consumption of high amounts of biogenic amines can cause toxicological effects, including serious gastrointestinal, cutaneous, hemodynamic, and neurological symptoms. In this study, a novel amperometric biosensor wasdeveloped to detect biogenic amines. The biosensor consisted of a working electrode, a reference electrode, a counter electrode, an enzyme reactor with immobilized diamine oxidase, an injector, a peristaltic pump and a potentiostat. A working electrode was fabricated with a glassy carbon electrode (GCE) by coating functionalized multi-walled carbon nanotubes (MWCNT-$NH_2$) and by electrodepositing Prussian blue (PB) to enhance electrical conductivity. A sensor system with PB/MWCNT-$NH_2$/GCE showed linearity in the range of $0.5 {\mu}M{\sim}100 {\mu}M$ hydrogen peroxide with a detection limit of $0.5 {\mu}M$. The responses for tyramine, 2-phenylethylamine, and tryptamine were 95%, 75%, and 70% compared to that of histamine, respectively. These results imply that the biosensor system can be applied to the quantitative measurement of biogenic amines.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.87.2-87.2
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• 2015

Transparent conductors are commonly used in photoelectric devices, where the electric energy converts to light energy or vice versa. Energy consumption devices, such as LEDs, Displays, Lighting devices use the electrical energy to generate light by carrier recombination. Meanwhile, solar cell is the only device to generate electric energy from the incident photon. Most photoelectric devices require a transparent electrode to pass the light in or out from a device. Beyond the passive role, transparent conductors can be employed to form Schottky junction or heterojunction to establish a rectifying current flow. Transparent conductor-embedded heterojunction device provides significant advantages of transparent electrode formation, no need for intentional doping process, and enhanced light-reactive surface area. Herein, we present versatile applications of transparent conductors, such as NiO, ZnO, ITO in photoelectric devices of solar cells and photodetectors for high-performing UV or IR detection. Moreover, we also introduce the growth of transparent ITO nanowires by sputtering methods for large scale application.

• Advances in Energy Research
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• v.7 no.1
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• pp.21-34
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• 2020

Energy storage devices have received a keen interest throughout the world due to high power consumption. A large number of research activities are being conducted on electrochemical double layer capacitors (EDLCs) because of their high power density and higher energy density. In the present study, an EDLC was fabricated using natural graphite based electrodes and ionic liquid (IL) based gel polymer electrolyte (GPE). The IL based GPE was prepared using the IL, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (1E3MITF) with the polymer poly(vinyl chloride) (PVC) and the salt magnesium trifluoromethanesulfonate (Mg(CF₃SO₃)₂ - MgTF). GPE was characterized by electrochemical impedance spectroscopy (EIS), DC polarization test, linear sweep voltammetry (LSV) test and cyclic voltammetry (CV) test. The maximum room temperature conductivity of the sample was 1.64 × 10^-4 Scm^-1. The electrolyte was purely an ionic conductor and the anionic contribution was prominent. Fabricated EDLC was characterized by EIS, CV and galvanostatic charge discharge (GCD) tests. CV test of the EDLC exhibits a single electrode specific capacitance of 1.44 Fg^-1 initially and GCD test gives 0.83 Fg^-1 as initial single electrode specific discharge capacitance. Moreover, a good stability was observed for prolonged cycling and the device can be used for applications with further modifications.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.3
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• pp.206-211
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• 2015

For the hydrogen production, Gas Lab and Gnc make alkaline watrer electrolyzer and found optimized condition of experimental parameters of cell material and operating procedures. For the commercial production, we saved electric power consumption and caloric based efficiency with over 70%. Used cell pressures are 10 bar, 30 bar and consumed electricity is $4,000A/m^2$, 4.19 kW ($T=100^{\circ}C$) at 10 bar. Another data is $2,000A/m^2$, 3.92 kW ($T=95^{\circ}C$) at 30 bar. Applied voltage is 1.75 V ($100^{\circ}C$, 10 bar), 1.64 V ($95^{\circ}C$, 10 bar), 1.81 V ($85^{\circ}C$, 30 bar), 1.76 V ($95^{\circ}C$, 30 bar). As cell temperature increase, applied voltage has been decreased and current has been increased. The concentration of KOH solution is 30 weight %.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.7
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• pp.558-562
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• 2012

As an alternative energy, Dye-sensitized solar cells (DSSCs) have received much attention due to low cost manufacturing procedure and high energy consumption rate. Incorporating scattering centers in the nanocrystalline photoanode or additional scattering layers on the nanocrystalline photoanode is an effective way to enhance the light harvest efficiency of the photoanode and the performance of dye-sensitized solar cells (DSSCs). The light scattering abilities of these scattering layers also depend on the relative sizes and phase of the particles in the layers. A higher surface area is normally obtained using large particle sizes. Therefore, transparent high surface area $TiO_2$ layers and an additional scattering layer consisting of $TiO_2$-Rutile 500 nm paste with relatively larger particles are attractive. In this work, we investigates the applicability of a hybrid $TiO_2$ electrode (or a working electrode with a light scattering layer) in a DSSCs. We fabrication various thin film using $TiO_2$ paste 20 nm and $TiO_2$ paste 500 nm. As a result, the efficiency of the a single structure thin film was 3.35% and the efficiency as scattering layer of hybrid structure thin film was 4.36%, 4.73%.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.1
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• pp.155-159
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• 2009

To increase the luminance and luminous efficacy in the discharge for alternating current plasma display panel (ac PDP), the increment of Xe contents and long discharge gap are necessary. However, the driving voltage and the cost of driving circuit increases in the high Xe contents and long discharge path condition. In this paper, a long gap ITO hump electrode (LGH) model for discharge cells of ac PDP is evaluated in the various Xe contents($5{\sim}20%$). The discharge voltage of LGH structure is lower about 30V than that of ITa reference structure with same main discharge gap. The LGH structure has lower power consumption and higher luminance than those of reference structure, respectively. Also, the luminous efficacy of LGH structure is higher about 20% than that of ITO reference structure in the 20% Xe contents.

• Journal of Environmental Science International
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• v.25 no.10
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• pp.1417-1426
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• 2016

Despite the low removal efficiencies reported by previous studies, electro-flotation still stands out among other microalgae removal methods for its economical and environmental benefits. To enhance removal efficiency, the important factors that limit the performance of this method must be investigated. In this study, the possible ways of increasing the removal efficiency of microalgae have been explored by investigating the effects of several important variables in electro-flotation. Eight parameters, namely flotation time, rising time, current density, pH, conductivity, electrode distance, temperature and initial concentration were evaluated using a one-parameter-at-a-time approach. Results revealed that the operational parameters that greatly affected the removal efficiency of microalgae were electro-flotation time, current density, pH, and initial concentration. The effect of conductivity, electrode distance, and temperature on removal efficiency were insignificant. However, they exhibited positive an indirect positive effect on power demand, which is nowadays considered an equally important aspect in the running of a feasible and economically efficient electro-flotation process.