• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.8
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• pp.340-346
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• 2002

Capacitor material utilized in the downsizing passive devices and integration of passive devices requires the physical and electrical properties at given area such as capacitor thickness reduction, relative dielectric constant increase, low leakage current and thermal stability. common capacitor materials, $Al_2O_3$, $SiO_2$, $Si_3N_4$, $SiO_2$/$Si_3N_4$, TaN and et al., used until recently have reached their physical limits in their application to integration of passive devices. $Ta_2O_{5}$ is known to be a good alternative to the existing materials for the capacitor application because of its high dielectric constant (25~35), low leakage current and high breakdown strength. Despite the numerous investigations of $Ta_2O_{5}$ material, there have little been established the clear understanding of the annealing effect on capacitance characteristic and conduction mechanism. This study presents the dielectric properties $Ta_2O_{5}$ MIM capacitor structure Processed by $O_2$ RTA oxidation. X-ray diffraction patterns showed the existence of amorphous phase in $600^{\circ}C$ annealing under the $O_2$ RTA and the formation of preferentially oriented-$Ta_2O_{5}$ in 650, $700^{\circ}C$ annealing and the AES depth profile showed $O_2$ RTA oxidation effect gives rise to the $O_2$ deficientd into the new layer. The leakage current density respectively, at 3~1l$\times$$10_{-2}$(kV/cm) were $10_{-3}$~$10_{-6}$(A/$\textrm{cm}^2$). In addition, behavior is stable irrespective of applied electric field. the frequency vs capacitance characteristic enhanced stability more then $Ta_2O_{5}$ thin films obtained by $O_2$ reactive sputtering. The capacitance vs voltage measurement that, Vfb(flat-band voltage) was increase dependance on the $O_2$ RTA oxidation temperature.

• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.902-908
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• 1995

Oxidative factors of lipid in the roasted laver Porphyra tenera(RL) and roasted-seasoned laver(R-SL) depending on various light sources, water activities, packaging materials and storage temperatures were investigated by peroxide value and color. Major fatty acids of RL were 46.4% eicosapentaenoic acid and 14.9% palmitic acid. Lipid oxidation was decreased in order of darkness, incandescent and fluorescent, decreased sharply with the decrease of water activity and temperature, and also reduced by the packaging material with strong barriers of water vapor, oxygen and light. From kinetics of lipid oxidation, it was supposed that oxidation of R-SL was three times faster than RL. On the other hand, reduction of the total chlorophyll content in RL was stronger than R-SL.

• Clean Technology
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• v.2 no.1
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• pp.60-68
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• 1996

The oxidation of carbon monoxide of low concentration on the natural manganese dioxide (NMD) has been investigated in a fixed bed reactor. The experimental variables were concentration of oxygen (500ppm~99.8%) and carbon monoxide (500ppm~10000ppm) and catalyst temperature ($50{\sim}750^{\circ}C$). The NMD(Natural Manganese Dioxide) has been characterized by temperature - program reduction(TPR) using 2.4% $CO/H_2$ as a reducing agent, thermogravimetric analysis (TGA), and reduction of NMD by 2.4% $CO/H_2$. It was found that the NMD catalyst activity on the unit area was greater than the $MnO_2$ catalyst for oxidation of CO at the same temperature. The thermal stability of oxidation activity was considered to be maintained when the NMD was heated to $750^{\circ}C$. The TGA, reduction by CO, and TPR of the NMD showed that the NMD had active lattice oxygen which was easily liberated on heating in the absence and low concentration of oxygen. The reaction order in CO is 0.701 between 500~3500ppm and almost zero between 3500~10000ppm of CO.

• Analytical Science and Technology
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• v.16 no.6
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• pp.431-437
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• 2003

Metalization yield of uranium oxide to uranium metal from lithium reduction process of spent pressurized water reactor (PWR) fuels was measured using thermogravimetric analyzer. A reduced metal produced in the process was divided into a solid and a powder part, and each metalization yield was measured. Metalization yield of the solid part was 90.7~95.9 wt%, and the powder being 77.8~71.5 wt% individually. Oxidation behaviour of the quartemary alloy was investigated to take data on the thermal oxidation stability necessary for the study on dry storage of the reduced metal. At $600{\sim}700^{\circ}C$, weight increments of alloy of Mo, Ru, Rh and Pd was 0.40~0.55 wt%. Phase change on the surface of the alloy was started at $750^{\circ}C$. In particular, Mo was rapidly oxidized and then the alloy lost 0.76~25.22 wt% in weight.

• Food Science of Animal Resources
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• v.32 no.4
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• pp.467-475
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• 2012

This study was carried out to investigate the effect of the addition level (0 ppm, 400 ppm, 800 ppm, and 1,200 ppm) of green tea extract on the lactic acid bacteria, oxidative stability, and aroma in kimchi-fermented sausage. The sample sausages were fermented at $24^{\circ}C/RH$ 89% until attained to a pH value of 4.9 (for 17 h), and then dried at $10^{\circ}C/RH$ 75-80% for 6 d. The lactic acid bacteria count and pH value were 7.5-7.7 Log CFU/g sausage and 4.30-4.33, respectively, at 6 d of ripening. The results of those did not show significant differences among all treatments. The formation of TBARS (2-thiobarbituric acid reactive substances) was significantly lowered by increasing the addition level of green tea extract. During ripening periods, the CIE $L^*$ and $a^*$ values decreased; however, the $b^*$ value increased due to the addition of green tea extract. Utilizing an electric nose, the aroma pattern was clearly discriminated between green tea extract treatments and the control. Therefore, in kimchi-fermented sausages, the high addition level of green tea extract improved the lipid oxidation stability. In addition, regardless of the addition level, green tea extract changed the aroma while reducing the color stability. Moreover, it did not have any effect on the growth of lactic acid bacteria.

• Korean Chemical Engineering Research
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• v.48 no.6
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• pp.690-694
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• 2010

In this study, herbal wood vinegar including Bambusoideae, Cinnamomi Cortex, Zingiberis Rhizoma was tested to see possibility for cosmetic or skin related medicine. Anti-oxidation effect of herbal wood vinegar was tested by DPPH free radical scavenging activity, and showed 97% inhibition rate at $50{\mu}g/ml$. Anti-bacterial effect was tested by disc diffusion method, and it indicated strong anti-bacterial activity against normal skin flora Staphylococcus aureus. Whitening effect was measured by tyrosinase inhibition assay, and it was lower compared with vitamin C. Stability test was done by MTT assay, and cell toxicity was relatively high. Stability was also checked, and there was not significant change in color, aroma, appearance and pH during storage. Anti-atopic dermatitis test was done by hairless mouse and herbal wood vinegar recovered damaged skin to almost normal condition after 9 days of application. IgE concentration in herbal wood vinegar treated mouse was also reduced 30% compared with control. From the study, herbal wood vinegar showed good anti-oxidation, anti-bacterial and anti-atopic dermatitis effect, and had promising application in cosmetic or skin related medicine.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.89-92
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• 2007

Partail oxidation(POX) of n-butane was investigated in this research by employing ceria-promoted Ni/calcium hydroxyapatite catalysts ($Ce_xNi_{2.5}Ca_{10}(OH)_2(PO_4)_6$ ; x = $0.1{\sim}0.3$) which had recently been reported to exhibit good catalytic performance in POX of methane and propane. The experiments were carried out with changing ceria content, $O_2/n-C_4H_{10}$ ratio and temperature. As the $O_2/n-C_4H_{10}$ feed ratio increased up to 2.75, n-$C_4H_{10}$ conversion and $H_2$ yield increased and the selectivity of methane and other hydrocarbons decreased. But with $O_2/n-C_4H_{10}$ = 3.0, $n-C_4H_{10}$ conversion and $H_2$ yield decreased. This is considered due to that too much oxygen may inhibit the reduction of Ni or induce the oxidation of Ni, which results in poor catalytic activity. The optimum $O_2/n-C_4H_{10}$ ratio lay between 2.50 and 2.75. $Ce_{0.1}Ni_{2.5}Ca_{10}(OH)_2(PO_4)_6$ showed the highest $n-C_4H_{10}$ conversion and $H-2$ yield on the whole. In durability tests, higher hydrogen yield and better catalyst stability were obtained with the $O_2/n-C_4H_{10}$ ratio of 2.75 than with the ratio of 2.5.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.2
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• pp.21-32
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• 2023

CuNWs(Copper nanowires) are attracting attention as a transparent electrode material because of their excellent electrical conductivity, high mechanical flexibility, and cost-effectiveness. However, since copper nanowires are easily oxidized, there is a disadvantage that properties of the transparent electrode may be deteriorated due to this, and researches are being conducted to improve this. Accordingly, in this review, various methods and studies to prevent oxidation and improve stability of copper nanowire transparent electrodes by using coating materials such as carbon-based materials, metals, and conductive polymers are introduced. Through this, we intend to provide solutions to solve the problem of development and oxidation of copper nanowire-based technology.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2007.11a
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• pp.161.1-161.1
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• 2007

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.287.2-287.2
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• 2013

We synthesized a new composite of poly sodium 4-styrenesulfonate intercalated graphene oxide for energy storage devices by controlling oxidation time in the synthesis of graphite oxide. Specific capacitance was improved from 20 F/g of the previous composites to 88 F/g of the new composite at the current density of 0.3 A/g. The capacitance retention was 94% after 3000 cycles, indicating that the new composites of high cyclic stability, prominent performance as electric double layer capacitor, and even low resistance could be an excellent carbon based electrode for further energy storage devices.