• Korean Journal of Animal Reproduction
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• v.9 no.1
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• pp.62-65
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• 1985

This study was conducted to investigate the effect of progesterone on the oxygen consumption of washed goat spermatozoa. The results obtained were summarized as follows: 1. Progesterone significantly depressed the respilation of the spermatozoa. 2. Caffeine and Di-cAMP greatly increased the oxygen consumption of the spermatozoa. 3. Caffeine plus progesterone and Di-cAMP plus progesterone significantly depressed the oxygen uptake of the cells. 4. There is some indication of a relationship between progesterone and its interference with metabolic behavior of sperm.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.145.1-145.1
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• 2016

Binding and unbinding between molecular oxygen and metallo-porphyrin is a key process for oxygen delivery in respiration. It can be also used to control spin state of magnetic metallo-porphyrin molecules. Controlling and sensing spin states of magnetic molecules in such reactions at the single molecule level is essential for spintronic molecular device applications. Here, we demonstrate that spin states of metallo-porphyrin on surfaces can be controlled over by binding and unbinding of oxygen molecule, and be sensed using scanning tunneling microscopy and spectroscopy. Kondo localized state of metallo-porphyrin showed significant modification by the binding of oxygen molecule, implying that the spin state was changed. Our density functional theory calculation results explain the observations with the hybridization of unpaired spins in d and ${\pi}^*$ orbitals of metallo-porphyrin and oxygen, respectively. Our study opens up ways to control molecular spin state and Kondo effect by means of molecular binding and unbinding reactions on surfaces.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.7
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• pp.275-282
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• 2016

MILD (Moderate and Intense Low-oxygen Dilution) combustion using oxygen as an oxidizer is considered as one of the most promising combustion technologies for high energy efficiency and for reducing nitrogen oxide and carbon dioxide emissions. In order to investigate the effects of nozzle angle and oxygen velocity conditions on the formation of oxygen-MILD combustion, numerical and experimental approaches were performed in this study. The numerical results showed that the recirculation ratio ($K_V$), which is an important parameter for performing MILD combustion, was increased in the main reaction zone when the nozzle angle was changed from 0 degrees to 15 degrees. Also, it was observed that a low and uniform temperature distribution was achieved at an oxygen velocity of 400 m/s. The perfectly invisible oxy-MILD flame was observed experimentally under the condition of a nozzle angle of $10^{\circ}$ and an oxygen velocity of 400 m/s. Moreover, the NOx emission limit was satisfied with NOx regulation of less than 80 ppm.

• Corrosion Science and Technology
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• v.2 no.4
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• pp.178-182
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• 2003

Slow Strain Rate Tests (SSRT) were carried out to investigate the effect of environmental factors on the Stress Corrosion Cracking (SCC) susceptibility of 3.5NiCrMoV steels used in discs for Low-Pressure (LP) steam turbines in electric power generating plants. The influences of dissolved oxygen on the stress corrosion cracking of turbine steel were studied, For this purpose, specimens were strained at variously oxygenated conditions at $150^{\circ}C$ in pure water. When the specimen was strained with $1{\times}10^{-7}s^{-1}$ at $150^{\circ}C$ in pure water, increasing concentration of dissolved oxygen decreased the elongation and the UTS. The corrosion potential and the corrosion rare increased as the amounts of dissolved oxygen increased. The increase of the SCC susceptibility of the turbine steel in a highly dissolved oxygen environment is due to the non protectiveness of the oxide layer on the turbine steel surface and the increase of the corrosion current. These results clearly indicate that oxygen concentration increases Stress Corrosion Cracking susceptibility in turbine steel at $150^{\circ}C$.

• Journal of the Semiconductor & Display Technology
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• v.22 no.3
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• pp.96-100
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• 2023

We have investigated the effect of the substrate temperature and oxygen flow rate on the characteristics of IGZO thin films for the TCO (transparent conducting oxide). For this purpose, IGZO thin films were deposited by RF magnetron sputtering at room temperature and 300℃ with various O₂ flow rate. Experiments were carried out while varying the oxygen gas flow rate from 0sccm to 1.0sccm to see how the oxygen gas affects the IGZO thin films. IGZO thin films deposited at room temperature and 300℃ showed amorphous. The lowest resistivity value was 2125x10^-3 Ωcm when the IGZO film was deposited at RT and set up at 0.1sccm. As the oxygen vacancy rate decreased, the resistivity intended to increase. In conclusion, Oxygen vacancy affects the IGZO thin film's electrical characteristic.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.11 no.2
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• pp.59-66
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• 2007

The oxygen distribution at steady state is analyzed mathematically in a hexagonal cylinder. The domain is penetrated by parallel cylindrical capillaries of different oxygen squirt. Asymptotic solution is used to determine the effect of axial diffusion. Oxygen concentration profiles are displayed at some positions of capillary-beds. At the venous end some tissue areas suffer from a shortage of oxygen.

• Food Science and Preservation
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• v.6 no.1
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• pp.115-120
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• 1999

This study was carried out to investigate the effect of Pine needle extract on lipid oxidation and free radical reaction in iron sources reacted with active oxygen species. The results were summarized as follow; The pine needle extracts didn`t show a distinct effect on reduction of lipid oxidation if the iron ion didn`t exist in oil emulsion. The pine needle extracts played role as a strong chelating agents to bind iron ion if Ferrous iron(Fe\ulcorner) exist in oil emulsion. Ferric iron(Fe) was lower effect than Ferrous iron(Fe) on free radical reaction in oil emulsion. And also, the Fe\ulcorner reacted with pine needle extract did not show distinct effect on free radical reaction, compared to Fe\ulcorner reacted with pine needle extract. And also, Pine needle extracts reacted with H\ulcornerO\ulcorner were tended to show a low oxygen scavenging ability in case of H\ulcornerO\ulcorner only was existed, compared to those of H\ulcornerO\ulcorner + Fe\ulcorner complex. Pine needle extracts were the most powerful Fe\ulcorner binding agents, compared to other strong synthetic antioxidants such as EDTA and DTPA.

• KSBB Journal
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• v.18 no.2
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• pp.155-160
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• 2003

The effect of dissolved oxygen(DO) on microbial transglutaminase(mTG) production by Streptoverticillium morbaraense was studied in on-line computer controlled fermentation system. In order to control dissolved oxygen during fermentation, the agitation speed and aeration rate of 2.5 L fermenter ranged from 260 to 360 rpm and 0.3 to 3.9 L/min, respectively. The maximum microbial transglutaminase production was obtained at controlled 20% of dissolved oxygen among the various dissolved oxygen controlled batch cultures tested. The production of microbial transglutaminase at controlled 20% of dissolved oxygen was about 2.12 U/mL which was 1.1 times higher than that obtained in batch culture without control of dissolved oxygen. Also, the highest microbial transglutaminase production was obtained in fed-batch cultures in which dissolved oxygen was controlled at 20%, and it was improved almost 1.3 times in comparison with that without control of dissolved oxygen. Maximal dry cell weight and microbial transglutaminase production were 13.2 g/L and 2.6 U/mL, respectively. Finally, it was also found that fed-batch fermentation at controlled 20% of dissolved oxygen showed a good performance for the microbial transglutaminase production by on-line computer controlled fermentation system which may be generally applicable to other microbial cultures.

• Journal of Hydrogen and New Energy
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• v.27 no.1
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• pp.95-105
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• 2016

Spray-dried NiO-based oxygen carriers developed for chemical looping combustion required high calcination temperatures above $1300^{\circ}C$ to obtain high mechanical strength applicable to circulating fluidized-bed process. In this study, the effect of CBB ($CaO{\cdot}BaO{\cdot}B_2O_3$) addition, as a binder, on the physical properties and oxygen transfer reactivity of spray-dried NiO-based oxygen carriers was investigated. CBB addition resulted in several positive effects such as reduction of calcination temperature and increase in oxygen transfer capacity and porosity. However, oxygen transfer rate was considerably decreased. This was more apparent when a higher amount of CBB was added and MgO was added together. From the experimental results, it is concluded that CBB added NiO-based oxygen carriers are not suitable for chemical looping combustion and a new method to reduce calcination temperature while maintaining high oxygen transfer rate of NiO-based oxygen carriers should be found out.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.4
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• pp.980-984
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• 2006

In order to examine the effect of oxygen free radicals on the vascular endothelial cells, cell viability was measured by XTT assay after bovine pulmonary vascular endothelial cell line(BPVEC) was treated only with hydrogen peroxide. In addition, the antioxidant effect of allopurinol on cells treated with hydrogen peroxide was examined by colormetric assay. in this study, the BPVEC treated with hydrogen peroxide showed the significantly decreased cell viability compared with control. Whereas, the viability of cells treated with hydrogen peroxide and allopurinol has significantly increased when compared with that of cells treated only with hydrogen peroxide. These results suggested that hydrogen peroxide, one of the oxygen free radicals showed cytotoxic effect and allopurinol has protective effect on oxygen free radical-induced cytotoxicity.