• Korean Journal of Poultry Science
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• v.25 no.2
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• pp.79-89
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• 1998

Dietary levels of single cell protein(SCP) 0 %, 5 %, 10 % and 15 % were included in experimental diets. The purpose of this experiment is to examine the effects of diets containing different levels of SCP on the performance of broiler chicks, including the nutrient availabilities, compared to that of the commercial diet. In order to evaluate the nutritive value of SCP, feeding and metabolism trial were conducted with a total of 160 broiler chicks for a period of 4 weeks. Contents of CP and pure protein in the composition of SCP were 67 % and 32. 05 %, respectively. In general, diets with over 10 % SCP substitution had significantly decreased body weight gain compared to the control diet. Feed intake of chicks fed SCP supplemental groups was significantly decreased compared to that of control, especially observed the significant difference in proportion to increas mg the levels of SCP. The feed efficiency was decreased by the addiition of SCP, but was not significantly different between control and SCP supplemental groups. The digestibilities of DM, CP and NFE tended to be similar among treatments, whereas crude fiber treated with SCP tended to be lower digestibility than control. In conclusion, the optimum dietary supplemental SCP would be less 5 % for broiler growth in this experiment.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.45-48
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• 2008

This paper presents a passive air-breathing direct methanol fuel cell (DMFC) which has been designed and tested. The single cell is fuelled by methanol vapor that is supplied through flow channel from a methanol reservoir at the anode, and the oxygen is supplied via natural air-breathing at the cathode. The methods for supplying the methanol vapor to the single cell were parallel channel and chamber. This research investigates various methods to identify the effects of using flow channels for providing the methanol vapor at the anode, and the opening ratio between the inlet and outlet ports for the methanol flow at the anode. The best flow channel condition for passive DMFC was a chamber, and the opening ratio was 0.8. Under these conditions, the peak power was 10.2mW/$cm^2$ at room temperature and ambient pressure. The key issues for the Passive DMFCs for using methanol vapor are that sufficient methanol needs to be supplied using a large as possible opening ratio. However, it is shown that the performance of the passive DMFC, which has a channel at the anode,is low due to the low differential pressure and insufficient methanol supply rate.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.124.1-124.1
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• 2010

The impurities in the methanol fuel that is used for direct methanol fuel cell (DMFC) could greatly affect the performance of membrane electrode assemblies (MEA). The most common impurities in the commercial methanol fuel are mainly ethanol, acetone, acetaldehyde, or ammonia. In this study, the effect of impurities in methanol fuel was investigated on the performance of MEA. The MEA for DMFC were prepared using a semi-automatic bar-coating machine, which can prepare the catalyst layer with uniform thickness for MEA. As a result, a single cell supplied with one of the 6 different kinds of methanol fuels showed a significant degradation of the fuel cell performance. The most common impurities in the commercial methanol fuel is mainly ethanol, acetone, acetaldehyde, or ammonia. The effects of the kind and the concentration of impurities in the methanol fuels were investigated on the performance of MEA for DMFC. We will propose the optimum compositions and limit concentration of impurities in methanol fuel for high performance of MEA for DMFC.

• Korean Journal of Materials Research
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• v.14 no.5
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• pp.368-373
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• 2004

To improve the conventional cathode-supported tubular solid oxide fuel cell (SOFC) from the viewpoint of low cell power density, expensive fabrication process and high operation temperature, the anode-supported tubular solid oxide fuel cell was investigated. The anode tube of Ni-8mol% $Y_2$O$_3$-stabilized $ZrO_2$ (8YSZ) was manufactured by extrusion process, and, the electrolyte of 8YSZ and the multi-layered cathode of $LaSrMnO_3$(LSM)ILSM-YSZ composite/$LaSrCoFeO_3$ were coated on the surface of the anode tube by slurry dip coating process, subsequently. Their cell performances were examined under gases of humidified hydrogen with 3% water and air. In the thermal cycle condition of heating and cooling rates with $3.33^{\circ}C$/min, the anode-supported tubular cell showed an excellent resistance as compared with the electrolyte-supported planar cell. The optimum hydrogen flow rate was evaluated and the air preheating increased the cell performance due to the increased gas temperature inside the cell. In long-term stability test, the single cell indicated a stable performance of 300 mA/$\textrm{cm}^2$ at 0.85 V for 255 hr.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.202-202
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• 2010

This study focused on the characteristics of single crystal solar cell using the impedance technique. In this experiment, the impedance was measured according to frequency's from 1mHz until 2MHz. The solar cell is R-L-C series circuit. Capacitance reactance was changed according to changing from low frequency to high frequency. It could know that the impedance was changed according to the frequency increases in solar cell.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.12
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• pp.1022-1030
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• 2009

Numerical analysis was carried out to investigate the effect of GDL (Gas diffusion layer) porosity on the performance of PEMFC (proton exchange membrane fuel cell). A complete three-dimensional model was chosen for single straight channel geometry including cooling channel. Main emphasis is placed on the heat and mass transfer through the GDL with different porosity. The present numerical results show that at high current densities, the cell voltage is influenced by the GDL porosity while the cell performance is nearly the same at low current densities. At high current densities, low value of GDL porosity results in decrease of the fuel cell performance since the diffusion of reactant gas through GDL becomes slow with decreasing porosity. On the other hand, for high GDL porosity, the effective thermal conductivity becomes low and the heat generated in the cell is not removed rapidly. This causes the temperature of fuel cell to increase and gives rise to dehydration of the membrane, and ultimately increase of the ohmic loss.

• Membrane Journal
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• v.32 no.6
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• pp.496-513
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• 2022

In this study, we sought to verify the applicability of anion exchange membrane water electrolysis system using FAA-3-50, Neosepta-ASE, Sustainion grade T, and Fujifilm type 10, which are commercial anion exchange membranes. The morphology of the commercial membranes and the elements on the surface were analyzed using SEM/EDX to confirm the distribution of functional groups included in the commercial membranes. In addition, mechanical strength and decomposition temperature were measured using UTM and TGA to check whether the driving conditions of the water electrolyte were satisfied. The ion exchange capacity and ion conductivity were measured to understand the performance of anion exchange membranes, and the alkaline resistance of each commercial membrane was checked and durability test was performed because they were driven in an alkaline environment. Finally, a membrane-electrode assembly was manufactured and a water electrolysis single cell test was performed to confirm cell performance at 60℃, 70℃, and 80℃. The long-term cell test was measured 20 cycles at other temperatures to compare water electrolysis performance.

• Journal of Digital Convergence
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• v.19 no.5
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• pp.279-284
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• 2021

In this study, the performance and distribution of fluid concentration, pressure, and current density of a proton exchange membrane fuel cell was investigated. In this paper, the two different types of flow field design were compared, singel channel and 5-channels. As a result, the 5-channels of flow field showed the better performance than that of single chanel. Especially, the single channel showed better performance in terms of mass transfer loss area.

• Transactions of the Korean hydrogen and new energy society
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• v.14 no.4
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• pp.291-297
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• 2003

As an alternative bipolar plate material for polymer electrolyte membrane fuel cell (PEMFC), TiN-coated 316 stainless was evaluated in terms of electrical contact resistance and water contact angle. Performance and lifetime of the TiN-coated 316 bipolar plates were measured in comparison with those of graphite and bare 316 bipolar plates. At a cell voltage of 0.6 V, current density of the single cells using graphite, AISI 316, and TiN/316 bipolar plates was 996, 796, and $896mA/cm^2$, respectively. By coating 316 stainless steel with TiN layer, performance degradation rate determined to be the voltage degradation rate at a cell voltage of 0.6 V was reduced from 2.3 to 0.43 mV/h.

• KEPCO Journal on Electric Power and Energy
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• v.5 no.2
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• pp.121-125
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• 2019

A YSZ electrolyte based ceramic supported Solid Oxide Cell (SOC) and a metal interconnect supported SOC was investigated under both fuel cell and co-electrolysis (steam and $CO_2$) mode at $800^{\circ}C$. The single cell performance was analyzed by impedance spectra and product gas composition with gas chromatography(GC). The long-term performance in the co-electrolysis mode under a current density of $800mA/cm^2$ was obtained using steam and carbon dioxide ($CO_2$) mixed gas condition.