• Journal of Korean Society of Water and Wastewater
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• v.25 no.2
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• pp.223-230
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• 2011

An electrolytic oxidation process was applied to remove odorous compounds from non-point odor sources including wastewater pipelines and manholes. In this study, a distance between the anode and the cathode of the electrolytic process was varied as a system operating parameters, and its effects on odor removal efficiencies and reaction characteristics were investigated. Odor precursors such as sediment organic matters and reduced sulfur/nitrogen compounds were effectively oxidized in the electrolytic process, and a change in oxidation-reduction potential (ORP) indicated that an stringent anaerobic condition shifted to a mild anoxic condition rapidly. At an electrode distance of 1 cm and an applied voltage of 30 V, a system current was maintained at 1 A, and the current density was 23.1 $mA/cm^{2}$. Under the condition, the removal efficiency of hydrogen sulfide in gas phase was found to be 100%, and 93% of ammonium ion was removed from the liquid phase during the 120 minute operating period. Moreover, the sulfate ion (${SO_4}^{2-}$) concentration increased about three times from its initial value due to the active oxidation. As the specific power consumption (i.e., the energy input normalized by the effective volume) increased, the oxidation progressed rapidly, however, the oxidation rate was varied depending on target compounds. Consequently, a threshold power consumption for each odorous compound needs to be experimentally determined for an effective application of the electrolytic oxidation.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.58.2-58.2
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• 2012

Heavy hydrocarbon reforming is a core technology for "Dirty energy smart". Heavy hydrocarbons are components of fossil fuels, biomass, coke oven gas and etc. Heavy hydrocarbon reforming converts the fuels into $H_2$-rich syngas. And then $H_2$-rich syngas is used for the production of electricity, synthetic fuels and petrochemicals. Energy can be used efficiently and obtained from various sources by using $H_2$-rich syngas from heavy hydrocarbon reforming. Especially, the key point of "Dirty energy smart" is using "dirty fuel" which is wasted in an inefficient way. New energy conversion laboratory of KAIST has been researched diesel reforming for solid oxide fuel cell (SOFC) as a part of "Dirty energy smart". Diesel is heavy hydrocarbon fuels which has higher carbon number than natural gas, kerosene and gasoline. Diesel reforming has difficulties due to the evaporation of fuels and coke formation. Nevertheless, diesel reforming technology is directly applied to "Dirty fuel" because diesel has the similar chemical properties with "Dirty fuel". On the other hand, SOFC has advantages on high efficiency and wasted heat recovery. Nippon oil Co. of Japan recently commercializes 700We class SOFC system using city gas. Considering the market situation, the development of diesel reformer has a great ripple effect. SOFC system can be applied to auxiliary power unit and distributed power generation. In addition, "Dirty energy smart" can be realized by applying diesel reforming technology to "Dirty fuel". As well as material developments, multidirectional approaches are required to reform heavy hydrocarbon fuels and use $H_2$-rich gas in SOFC. Gd doped ceria (CGO, $Ce_{1-x}Gd_xO_{2-y}$) has been researched for not only electrolyte materials but also catalysts supports. In addition, catalysts infiltrated electrode over porous $La_{0.8}Sr_{0.2}Ga_{0.8}Mg_{0.2}O_3-{\delta}$ and catalyst deposition at three phase boundary are being investigated to improve the performance of SOFC. On the other hand, nozzle for diesel atomization and post-reforming for light-hydrocarbons removal are examples of solving material problems in multidirectional approaches. Likewise, multidirectional approaches are necessary to realize "Dirty energy smart" like reforming "Dirty fuel" for SOFC.

• Journal of the Korean Magnetics Society
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• v.25 no.5
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• pp.149-155
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• 2015

The ECR (Electron Cyclotron Resonance) Ar ion milling was manufactured to fabricate the device of thin film. The ECR ion milling system applied to the device etching operated by a power of 600W, a frequency of 2.45 GHz, and a wavelength of 12.24 cm and transferred by a designed waveguide. In order to match one resonant frequency, a magnetic field of 908 G was applied to a cavity inside of ECR. The Ar gas intruded into a cavity and created the discharged ion beam. The surface of target material was etched by the ion beam having an acceleration voltage of 1000 V. The formed devices with a width of $1{\mu}m{\sim}9{\mu}m$ on the GMR-SV (Giant magnetoresistance-spin valve) multilayer after three major processes such as photo lithography, ion milling, and electrode fabrication were observed by the optical microscope.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.8
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• pp.129-135
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• 2016

This study is about ionic water generator filter Recently, a lot of people feel deep interest in health and drinking water. Evaluation of the stability of oxidation-reduced potential (ORP) using the filter of the alkaline water. This study utilizes the three filter of activated carbon, UF, carbon block in alkaline reduced water equipment. Passing the water to the filter is evaluated that the OPR values are stability in accordance with the change of the volume in the bucket. Alkaline reduced water equipment is a system that has the function of making the water reduction. This system is the values of the human body beneficial minerals and ORP are made in the functional water has a very low value than general water. Which has passed through the filter the water in the water negative ions and positive ions through the electrolytic. After electrolysis, the cathode side by water, including $Ca^+$, $K^+$, $Mg^+$, $Na^+$ water gets Alkaline Reduced Water containing the minerals beneficial to the human body. A positive electrode side is made of the organic materials that have an anion such as chlorine (Cl), phosphorus (P), sulfur(S). This experiment uses the Alkaline Reduced Water to adjust the magnitude of the voltage of the electrolysis in the Alkaline Reduced Water. That is 1st step(pH8) 2nd step (pH8.5) 3th step (pH9), 4th step (pH9.5) in the Alkaline Reduced Water and -1st step (pH6.0), -2nd step (pH5.0) used as the acidic oxidation water. When the water passes through the three filter in this system was evaluated whether the ORP values are changed and stabilized. When about 100 liters of water passing through the filter was confirmed that the ORP values are stability and evaluation.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.1
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• pp.57-62
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• 2009

Purpose: TiN films were deposited on sus304 by unbalanced magnetron sputtering system which was designed and developed as unbalancing the strength of the magnets in the magnetron electrode. The color and hardness of deposited TiN films was investigated. Methods: The cross sections of deposited films on silicon wafer were observed by SEM to measure the thickness of the films, the components of the surface of the films were identified by XPS, the components of the inner parts of the films were observed by XPS depth profiling. XPS high resolution scans and curve fittings of deposited films were performed for quantitative chemical analysis, Vickers micro hardness measurements of deposited films were performed with a nano indenter equipment. Results: The colors of deposited films gradually changed from light gold to dark gold, light violet, and indigo color with increasing of the thickness. It could be seen that the color change come from the composite change of three compound,$TiO_{x}N_{y}$, $TiO_2$, TiN. Especially, the composite change of$TiO_{x}N_{y}$ compound was thought to affect the color change with respect to thickness. Conclusions: Deposited films had lower than the value of general TiN film in Vickers hardness, which was caused by mixing three TiN, $TiO_2$,$TiO_{x}N_{y}$ compound in the deposited films. The increasing and decreasing of micro hardness with respect to thickness was thought to have something to do with the composite of TiN in the films.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.12
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• pp.635-640
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• 2016

Although microbial fuel cell (MFC) can produce electricity from organics in wastewater, nitrogen removal is required for application of process for wastewater treatment plant. This study developed flat-panel air-cathode MFCs (FA-MFCs) comprised of two large separator electrode assemblies (SEAs) and evaluate total nitrogen removal according to three inoculum sources and pre-nitrification acclimation. The nitrification efficiencies were >99% regardless of inoculum sources under the phase for pre-nitrification acclimation. The total nitrogen removal efficiencies of FA-MFCs without pre-nitrification acclimation were the highest at the low organic conditions (<300 mg-COD/L) under the phase for nitrification and denitrification. The increase of organic concentration influenced the total nitrogen removal efficiency, positively. The organics were removed >95% but were not used for heterotrophic denitrification totally. This study suggests that application of FA-MFC system for wastewater treatment can allow the simultaneous removal of organic and nitrogen compounds, although this affects the low electricity production.

• Journal of the Korean Electrochemical Society
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• v.25 no.4
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• pp.174-183
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• 2022

Polymer electrolyte fuel cells and water electrolysis are attracting attention in terms of high energy density and high purity hydrogen production. The catalyst layer for the polymer electrolyte fuel cell and water electrolysis is a porous electrode composed of a precious metal-based electrocatalyst and an ionomer binder. Among them, the ionomer binder plays an important role in the formation of a three-dimensional network for ion conduction in the catalyst layer and the formation of pores for the movement of materials required or generated for the electrode reaction. In terms of the use of commercial perfluorinated ionomers, the content of the ionomer, the physical properties of the ionomer, and the type of the dispersing solvent system greatly determine the performance and durability of the catalyst layer. Until now, many studies have been reported on the method of using an ionomer for the catalyst layer for polymer electrolyte fuel cells. This review summarizes the research results on the use of ionomer binders in the fuel cell aspect reported so far, and aims to provide useful information for the research on the ionomer binder for the catalyst layer, which is one of the key elements of polymer electrolyte water electrolysis to accelerate the hydrogen economy era.

• Journal of the Korean Applied Science and Technology
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• v.34 no.2
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• pp.376-381
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• 2017

We were investigated by cyclic voltammetry to the stability through the electrochemical characteristics of Langmuir-Blodgett films mixed with myristic acid and stearic acid. Fatty acid mixture monolayer LB films was deposited by the LB method on the indium tin oxide(ITO) glass. The electrochemical properties was measured by cyclic voltammetry with a three-electrode system in 0.01 N $NaClO_4$ solution. The measuring range is continuously oxidized to 1650 mV, with an initial potential of -1350 mV was reduced. Scanning rates of 50, 100, 150, 200, and 250 mV/s was set. As a result, LB monolayer films of fatty acid mixture was appeared on irreversible processes by the oxidation current from the cyclic voltammogram. Diffusion coefficient (D) of fatty acid mixture was calculated $7.9{\times}10^{-2}cm^2s^{-1}$ at 0.01 N $NaClO_4$ solution.

• Journal of the Korean Electrochemical Society
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• v.3 no.2
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• pp.85-89
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• 2000

For replacing Li metal at Lithium ion Battery(LIB) system, we used carbon powder material which prepared by Pyrolysis of Phenol resin as starting material. It became amorphous carbon by Pyrolysis through it's self condensation by thermal treatment. Amorphous carbon can be doped with Li intercalation and deintercalation because it has wide interlayer. However, it has a problem with structural destroy due to weak carbon-carbon bond. So, we used $ZnCl_2$ as the pore-forming agent. This inorganic salt was used together with the resin serves not only as the pore-forming agent to form open pores, which grow into a three-dimensional network structure in the cured material, but also as the microstructure-controlling agent to form a loose structure doped with bulky dopants. We used SEM in order to find to difference of structure, and can calculate the distance of interlayer by XRD analysis. CV test showed oxidation and reduction.

• Journal of Environmental Health Sciences
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• v.39 no.3
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• pp.289-299
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• 2013

Objectives: For the field application of the dielectric barrier discharge plasma reactor, scale-up of the plasma reactor is needed. This study investigated the possibility of inactivation of microorganisms in sewage using pilot multi-plasma reactor. We also considered the possibility of degradation of total organic carbon (TOC) and nonbiodegradable matter ($UV_{254}$) in sewage. Methods: The pilot plasma reactor consists of plasma reactor with three plasma modules (discharge electrode and quartz dielectric tube), liquid-gas mixer, high voltage transformers, gas supply equipment and a liquid circulation system. In order to determine the operating conditions of the pilot plasma reactor, we performed experiments on the operation parameters such as gas and liquid flow rate and electric discharge voltage. Results: The experimental results showed that optimum operation conditions for the pilot plasma reactor in batch experiments were 1 L/min air flow rate), 4 L/min liquid circulation rate, and 13 kV electric discharge voltage, respectively. The main operation factor of the pilot plasma process was the high voltage. In continuous operation of the air plasma process, residual microorganisms, $UV_{254}$ absorbance and TOC removal rate at optimal condition of 13 kV were $10^{2.24}$ CFU/mL, 56.5% and 8.6%, respectively, while in oxygen plasma process at 10 kV, residual microorganisms, $UV_{254}$ absorbance and TOC removal rate at optimal conditions were $10^{1.0}$ CFU/mL, 73.3% and 24.4%, respectively. Electric power was increased exponentially with the increase in high voltage ($R^2$ = 0.9964). Electric power = $0.0492{\times}\exp^{(0.6027{\times}lectric\;discharge\;voltage)}$ Conclusions: Inactivation of microorganisms in sewage effluent using the pilot plasma process was done. The performance of oxygen plasma process was superior to air plasma process. The power consumption of oxygen plasma process was less than that of air plasma process. However, it was considered that the final evaluation of air and oxygen plasma must be evaluated by considering low power consumption, high process performance, operating costs and facility expenses of an oxygen generator.