• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.8
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• pp.1370-1376
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• 2003

We investigated the effect of seatangle drink and seatangle extract on lipid oxidation, blood coagulation and intestinal movement in rats fed a hyperlipidemic diet. In the dietary hyperlipidemic induced group, the serum superoxide dismutase activity decreased and formation of hydroxy radical increased when compared to normal group, but these were controlled by seatangle drink treatment. The decreased of bleeding time and increased of tissue factor in the dietary hyperlipidemic rats were regulated by seatangle drink and seatangle extract, and especially the activity of tissue factor was remarkably decreased. Seatangle drink and seatangle extract were increased contraction on intestinal movement. Therefore, it can be concluded that seatangle drink or seatangle extract treatment depresses changing in absorption of gastrointestinal track in rats fed a hyperlipidemic diet.

• Journal of the Korean institute of surface engineering
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• v.55 no.4
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• pp.196-201
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• 2022

This paper deals with anodic oxidation behavior of AZ31 Mg alloy in aqueous solutions containing various NaF concentrations from 0.01 M to 1 M. Three different voltage-time curves and anodic oxide formation behaviors appeared with concentration of NaF in deionized water. When NaF concentration is lower than 0.02 M, the voltage of AZ31 Mg alloy increased linearly and then reached a steady-state value more than 200 V, and large size pits and thin oxide layer were formed. When NaF concentration is between 0.05 M and 0.1 M, the voltage of AZ31 Mg alloy showed large periodic fluctuations of about 30 ~ 50 V around more than 200 V and large number of small particles were observed. If NaF concentration is higher than 0.2 M, PEO films can be formed without visible arcs under solution pH 6.5 ~ 7.5 by F^- ions without help of OH^- ions.

• Journal of the Korean Society for Heat Treatment
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• v.17 no.2
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• pp.87-93
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• 2004

Nitrocarburizing was carried out with various $CH_4$ gas composition with 4 torr gas pressure at $570^{\circ}C$ for 3 hours and post oxidation was carried out with 100% $O_2$ gas atmosphere with 4 torr at different temperatures for various time. In the case of plasma nitrocarburizing, It is that the ratio of ${\varepsilon}-Fe_{2-3}$(N, C) and ${\gamma}^{\prime}-Fe_4$(C, N), which comprise the compound layer phase, depend on concentrations of $N_2$ gas and $CH_4$ such that when the concentration of $N_2$ and $CH_4$ increased, the ratio of ${\gamma}^{\prime}-Fe_4$(C, N) decreased, but the ratio of ${\varepsilon}-Fe_{2-3}$(N, C) increased. The thickness of compound layer consistently increased as gas concentration increased regardless of $N_2$ and $CH_4$ expect when the concentration of $CH_4$ was 3.5 volume%, it decreased insignificantly. When oxidizing for 15min in the temperature range of $460{\sim}570{^\circ}C$, the study found small amount of $Fe_3O_4$ at the temperature of $460{^\circ}C$ and also found that amounts of $Fe_2O_3$. and $Fe_3O_4$ on the surface and amount of ${\gamma}^{\prime}-Fe_4$(C, N) in the compound layer increased as the increased over $460^{\circ}C$, but the thickness of the compound layer decreased. Corrosion resistance was influenced by oxidation times and temperature.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.11
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• pp.934-940
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• 2001

Magnetic properties were investigated for Si/SiO$_2$/NiFe(300 )/A1$_2$O$_3$(t)/Co(200 ) junction related with the parameters of $Al_2$O$_3$. Insulating $Al_2$O$_3$ layer was formed by depositing a 5~40 thick Al layer, followed by a 90~120s RF plasma oxidation in an $O_2$ atmosphere. Magnetoresistance was not observed for tunnel junction with 5~10 thick Al layer, but magnetoresistance was observed large for tunnel junction with 15~40 thick Al layer. Oxidation time did not largely influence magnetoresistance. Tunnel magnetoresistance effect depended on magnetization behavior of two ferromagnetic layers. Tunneling junction was confirmed through nonlinear I-V curve. In this work, tunneling magnetoresistance(TMR) up to 30 % was observed. This apparent TMR is an artifact of the nonuniform current flow over the junction in the cross geometry of the electrodes.

• Journal of the Korean Magnetics Society
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• v.14 no.3
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• pp.99-104
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• 2004

We have studied to understand the barrier and interface qualities and structural changes through measuring temperature dependent spin-polarization as functions of plasma oxidation time and annealing time. Magnetic tunnel junctions consisting of SiO2$_2$/Ta 5/CoFe 17/IrMn 7.5/CoFe 5/Al 1.6-Ox/CoFe 5/Ta 5 (numbers in nm) were deposited and annealed when necessary. A 30 s,40 s oxidized sample showed the lowest spin-polarization values. It is presumed that tunneling electrons were depolarized and scattered by residual paramagnetic Al due to under-oxidation. On the contrary, a 60s, 70 s oxidized sample might have experienced over-oxidation, where partially oxidized magnetic dead layer was formed on top of the bottom CoFe electrode. The magnetic dead layer is known to increase the probability of spin-flip scattering. Therefore it showed a higher temperature dependence than that of the optimum sample (50 s oxidation). temperature dependence of 450 K annealed samples was improved when the as-deposited one compared. But the sample underwent 475 K and 500 K annealing exhibits inferior temperature dependence of spin-polarization, indicating that the over-annealed sample became microstucturally degraded.

• Transactions of the Korean hydrogen and new energy society
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• v.32 no.1
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• pp.68-76
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• 2021

Climate change problems occur during the use of fossil fuel and the process of biogas production. Research continues to convert carbon dioxide and methane, the major causes of climate change, into high-quality energy sources. in order to present the performance potential for the novel plasma-recuperative burner reformer, the reforming characteristics for each variable were indentified. The optimal operating condition of was an O2/C ratio of 1.0 and a total gas supply of 20 L/min. At this time, CH4 conversion was 64%, H2 selectivity was 39%, and H2/CO ratio was 1.13, which were the results applicable to the solid oxide fuel cell fuel stack for RPG, or Residential Power Generator. Recirculation of reformed gas increases the amount of H2 and CO, which are combustible gases, especially the amount of H2. As a result, the H2 selectivity is improved, and high-quality gas can be produced.

• The Journal of Engineering Geology
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• v.32 no.1
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• pp.127-142
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• 2022

This study explored the fluid transfer characteristics of simultaneous pneumatic blasting, plasma blasting, and vacuum suction (the PPV method), and assessed their effect. Chemical oxidation-an established soil remediation method-was compared as a control. Electrical resistivity surveys found that PPV reduced resistivity by about 1.5-2.5 times compared with the control group, indicating that it increased the diffusion of fluid between the injection and suction wells. Injection and suction tests comparing the injection flow rate, initial suction flow rate time, and suction flow rate showed that the PPV method offered an improvement over the existing method. Slug tests revealed that PPV increased the permeability coefficient by a greater amount than that by the control method. This study qualitatively and quantitatively confirmed that the PPV method clearly improves injection and suction efficiency by accelerating cracks in the ground and improving water permeability compared with the established chemical oxidation method.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.6
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• pp.815-824
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• 2011

In this study, a non-thermal plasma system was employed to simultaneously remove odorous compounds and organic sludge. The system consisted of two reactors; the first one was the non-thermal plasma reactor where ozone was produced by the plasma reaction and the ozone oxidized hydrogen sulfide, the model odorous compound, and then the ozone-laden gas stream was introduced to the second reactor where wasted sludge was disintegrated and solubilized by ozone oxidation. In this study, the gas retention time (GRT) and the hydraulic retention time (HRT) were changed in the two-reactor system, and the effects of GRT and HRT on reduction efficiencies of odor and sludge were determined. As the GRT increased, the ozone concentration increased resulting in an increasing efficiency of hydrogen sulfide removal. However, the overall ozone loading rate to the second sludge reactor was the same at any GRT, which resulted in an insignificant change in sludge reduction rate. When HRTs in the sludge reactor were 1, 2, 4 hours, the sludge reduction rates were approximately 30% during the four-hour operation, while the rate increased to 70% at the HRT of 6 hours. Nevertheless, at HRTs greater than 4 hours, the solubilization efficiency was not proportionally increased with increasing specific input energy, indicating that an appropriate sludge retention time needs to be applied to achieve effective solubilization efficiencies at a minimal power consumption for the non-thermal plasma reaction.

• Journal of the Korean institute of surface engineering
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• v.50 no.1
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• pp.10-16
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• 2017

This article reports for the first time on the lateral growth of PEO (plasma electrolytic oxidation) films on Al1050 alloy by the application of anodic pulse current in an alkaline electrolyte. Generation of microarcs was observed at the edges initially and then moved towards the central region with PEO treatment time. Disc type PEO film islands with about $20{\mu}m$ diameter were formed first and they grew laterally by the formation of new disc type PEO films at the edge of pre-formed PEO islands. The PEO film islands were found to be interconnected completely and form a continuous PEO film when generation of small size microarcs are terminated at the central part of the specimen, resulting in very smooth surface with low surface roughness less than $1{\mu}m$ of $R_a$. Further PEO treatment after the complete interconnection of PEO films islands showed local thickening of PEO films by vertical growth. It is concluded that very smooth PEO film surface can be obtained by lateral growth mechanism rather than vertical growth of them.

• Nutrition Research and Practice
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• v.8 no.1
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• pp.59-65
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• 2014

There is currently no reference for intake of lysine for Chinese people; therefore, the present study was conducted to determine the lysine requirement of Chinese young male adults on a habitual Chinese mixed diet based on the modified indicator amino acid oxidation method. Seven young men with a mean age of $23.7{\pm}2.2$ years that were healthy based on questionnaire, physical examinations and screening tests were evaluated. Subjects were evaluated over five consecutive 7 day periods, during which time they were administered decreasing amounts of lysine via the diet (65, 55, 45, 35, $25mg{\cdot}kg^{-1}{\cdot}d^{-1}$). Subjects were allowed to adapt from day 1 to 6 and the isotopes were measured on day 7 in each period. The subjects' body weights, body compositions and plasma proteins were also examined during the study. Amino acid kinetics were measured based on the indicator amino acid oxidation technique using the $^{13}CO_2$ release rate and phenylalanine oxidation rate to estimate lysine requirements. Body weights, body compositions, and plasma proteins of subjects did not change significantly relative to those at baseline. The mean and the upper 95% CI of lysine requirements of Chinese habitual diets were determined to be 58.41 and $70.09mg{\cdot}kg^{-1}{\cdot}d^{-1}$, respectively, based on the $^{13}CO_2$ release rate and 54.28 and $65.14mg{\cdot}kg^{-1}{\cdot}d^{-1}$, respectively, based on the phenylalanine oxidation rate.