• Proceedings of the Materials Research Society of Korea Conference
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• 2007.11a
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• pp.19.2-19.2
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• 2007

• Proceedings of the KSEEG Conference
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• 2005.04a
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• pp.217-217
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• 2005

• Korean Journal of Environmental Biology
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• v.30 no.4
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• pp.349-354
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• 2012

To evaluate the biological response of sea squirt Halocynthia roretzi with different body size to heavy metals and its suitability for ecotoxicity assays, the effects of Cr, Cu and Zn on its clearance and oxygen consumption rates were investigated. Clearance and oxygen consumption rates of H. roretzi with various body sizes were calculated at different metal concentrations. Both clearance and oxygen consumption rate were negatively correlated with body sizes. Clearance rate of H. roretzi decreased gradually with increasing concentration of heavy metal, the decreasing rate was in an order of Cr>Cu>Zn. The oxygen consumption rate first increased at low metal concentration (below $100{\mu}g\;L^{-1}$) and then decreased rapidly with increasing metal concentrations. The decreasing rate was in an order of Cu>Cr=Zn. There was a trend that the clearance rate and oxygen consumption rate decreased drastically under a concentration of $400{\mu}g\;L^{-1}$, and then decreased smoothly when the metal ion concentration increased continually. So the oxygen consumption and clearance rate at a concentration of $400{\mu}g\;L^{-1}$ Cu could be thought as a suitable biological tool for exotoxicology analysis.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.88-88
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• 2010

We synthesized molybdenum thin films deposited by RF magnetron sputtering and physicochemical analysis was performed. The physical and chemical properties of these films were examined with X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The obtained film at the oxygen ratio of 0% showed crystallinity of cubic Mo(110) phase. After the oxygen ratio increased more than 5% in the sputter gas, the molybdenum films were formed as an amorphous phase. The thickness of the Mo thin film was drastically decreased from 1000 nm to ca 70 nm after introduction of oxygen in the sputter gas confirmed by spectroscopic ellipsometer (SE) and scanning electron spectroscopy (SEM). The calculated band gap of the film deduced from SE data increased from 3.17 to 3.63 eV by addition of oxygen in the sputter gas. The roughness of the Mo film was examined with atomic force microscopy (AFM) and it was dramatically decreased by introducing of oxygen during sputtering. XPS results revealed that the ratio of metallic Mo species in the film decreased by the contents of Mo(VI) species increased at the ratio of oxygen increased in the sputter gas and fully oxidized at low content of oxygen in the sputter gas.

• Textile Coloration and Finishing
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• v.8 no.3
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• pp.59-65
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• 1996

Cotton fabrics were treated by low temperature plasma and/or cellulase, and its physical and dyeing properties were investigated. All the pretreatments of the cotton with low temperature plasma of oxygen, nitrogen and argon slowed down the rate of weight loss of cotton in cellulase solution. Plasma pretreatment did not show any strength retention effect on cotton fiber in the subsequent cellulase treatment. Pretreatment of cotton with low temperature oxygen plasma decreased the rate of dyeing in direct dye bath, while cellulase or plasma/cellulase pretreatment increased the rate. Equilibrium dye uptake of cotton was not changed greatly by the pretreatments except the normal untreated cotton showed more or less high uptake. The pretreatment of cellulase with a water-soluble carbodiimide reduced the enzymatic activity, and did not show any strength retention of cotton in enzymatic weight loss.

• Proceedings of the Ginseng society Conference
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• 1990.06a
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• pp.45-48
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• 1990

Maltol(2-methyl-3-hydroxy-r-pyrone), a component known to be present in Korean Ginseng root showed an antioxidant action but its potency as an antioxidant was low; about 1150th that of other antioxidants such as p-phenylenediamine , BHA and BHT. However, maltol was able to protect the oxidation adamants in biological systems such as adriamycin-induced membrane damage in isolated cardiomyocytes, parquet-induced toxicities in isolated hepatocytes and repercussion injury in isolated hearts. The antioxidant action of maltol was also shown to be effective in vivo. The antioxidant action of this compound was probably due to the removal of hydroxyl radicals. In view of the roles of oxygen radical in various pathological processes, Korean Ginseng root, which contains several antioxidants including maltol, is expected to have beneficial efforts on the oxygen radical-involved processes. Keywords Maltol, Oxygen free radicals, Lipid preoccupation, Repercussion injury and Korean ginseng

• Journal of Microbiology and Biotechnology
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• v.7 no.5
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• pp.356-359
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• 1997

To study the relationship between oxygen tolerance and enzyme activity in the oxygen metabolism of bifidobacteria, the activities of catalase, superoxide dismutase (SOD), NADH oxidase and NADH peroxidase from six typical bifidobacteria and other bacteria were assayed by spectrophotometry. Catalase activity was hardly detected in any of the bifidobacteria tested. SOD activity was detected in every species including the Clostridium species. In particular SOD activity was notably high in the aerosensitive Bifidobacterium adolescentis. This fact indicates that SOD activity is not a critical factor to ensure aerotolerance. Aerosensitive B. adolescentis showed very low NADH oxidative enzyme activity whereas other aerotolerant bifidobacteria exhibited considerable activity for the enzymes. It seems that detoxification of $H_2O_2$ by NADH oxidative enzymes might be an important factor in improving for aerotolerant bifidobacteria survival rates in an oxygen environment.

• Journal of Sensor Science and Technology
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• v.15 no.2
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• pp.97-101
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• 2006

Silver electrode having a high Electrocatalytic activity is oxygen-permeable electrode, in which oxygen ad-atoms are adsorbed and moved toward YSZ electrolyte by bulk diffusion. It is the different point in comparison to usual porous electrodes, especially platinum, which react with oxygen only in TPBs(Three Phase Boundaries). Also ad-atoms at TPBs of Pt are diffused to YSZ electrolyte by interfacial diffusion mechanism. These properties were used for turning down the operating temperature of YSZ from over $600^{\circ}C$ to below $450^{\circ}C$. The different heat-treatment temperature between a working electrode and a reference electrode suppresses the formation of silver oxides and reduces a volatility of Ag as well. Above all, these own characteristics and special processes of Ag improved a long-term stability of a oxygen sensor.

• KSBB Journal
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• v.6 no.3
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• pp.231-240
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• 1991

Recently, developments of large scale and high density cell culture methods have been the objects of many researches, because the demand of various pharmaceutical products produced by animal cell culture has been rapidly increasing. The cell culture equipment should have the requirements such as sufficient oxygen transfer and mixing, low shear stress and surface tension, and small foaming. In order to develop a proper bioreactor meeting these requirements simultaneously, a perfluorocarbon having high solubility of oxygen was sprayed into the medium as an oxygen carrier instead of air. Also, a new impeller was developed and combined together with the perfluorocarbon spraying system so as to design a new bioreartor for cell cultivation. The new impeller had better characteristics of mixing and oxygen transfer than the paddle and cell-lift impellers based on the same, shear rate. But, it was observed that the volumetric oxygen transfer coefficient of the new bioreactor decreased with increasing cell density during E. coli fermentation.

• Journal of the Korean Ceramic Society
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• v.36 no.10
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• pp.1056-1061
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• 1999

Phase formation and oxygen ion conduction of La(Ba)Ga(Mg)O3-$\delta$ system was studied, BaLaGa3O7 and BaLaGaO4 formed as a secondary phase above the solubility limit of Ba2+ in La3+ sites. The oxygen ionic conductivity of La(Ba)Ga(Mg)O3-$\delta$ was 0.1 S/cm 80$0^{\circ}C$ The activation energy of the oxygen ion conduction was dependent on temperature. This value was higher at low temperature than at high temperature.