• Proceedings of the KSME Conference
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• 2008.11b
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• pp.1996-2000
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• 2008

In autothermal reforming reaction, oxygen to carbon ratio (OCR) and steam to carbon ratio (SCR) are significant factors, which control temperature and carbon deposition into the reactor. The OCR is more sensitive than the SCR to affect the temperature distribution and reforming efficiency. In conventional operation, hydrocarbon fuel, steam, and oxygen was homogeneously mixed and injected into the reactor in order to get hydrogen-rich gas. The temperature was abruptly raised due to fast oxidation reaction in the former part of the reactor. Deactivation of packed catalysts can be accelerated there. In the present study, therefore, the effect of the oxygen distribution is introduced and investigated to suppress the carbon deposition and to maintain the reactor in the mild operating temperature (e.g., $700{\sim}800^{\circ}C$). In order to investigate the effect numerically, the following models are adopted; heterogeneous reaction model and two-medium model for heat balance.

• Environmental Analysis Health and Toxicology
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• v.17 no.3
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• pp.219-224
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• 2002

This study was carried out to examine the effects of bis (tribytyltin)oxide (TBT), endocrine disrupting compounds (EDCs). on the changes of survival, growth and oxygen consumption rate in the oliver flounder, Paralichthys olivaceus. Oliver Flounders were exposed to sublethal concentration of TBT (0, 1.67, 3.20, 6.30 and 12.50 $\mu\textrm{g}$/L) during 6 weeks. Survival rate was decreased in a concentration and exposure period-dependent way and suddenly the reduction of more than 20% occurred at TBT concentration greater than 3.20 $\mu\textrm{g}$/L. after exposure 6 weeks. Growth rate and feed efficiency significantly decreased at concentration greater than 3.20 $\mu\textrm{g}$/L. Oxygen consumption rate was also decreased in a concentration-dependent way and significantly decreased to 17,48 and 67％ than that of the control at the TBT concentration of 3.20, 6.32 and 12.50 $\mu\textrm{g}$/L, respectively. This study revealed that high TBT concentration ($\geq$3.20 $\mu\textrm{g}$/L) reduced growth and oxygen consumption rates of the juvenile oliver flounder suggesting potential influence on the natural mortality of Paralichthys olivaceus in the coastal areas.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.3
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• pp.262-266
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• 2003

The present study was carried out to investigate the relationships among intertillage and muddying by free-ranging ducks (Chinese native ducks) and pH, dissolved oxygen of irrigation water, and physicochemical properties of soil. Two paddy fields comprised of the muddying (muddy water without physical stimulation to a rice plant by the ducks) and the control plots (no ducks) were used for this study. As a muddying plot, 50 hills were randomly selected and each hill was fenced with a wire net in order to prevent from stimulating physically by the ducks. The variation in irrigation pH was smaller in the muddying plot than the control plot, and the pH was around 7.4. Dissolved oxygen was significantly higher (P＜0.01) in the muddying plot than the control plot during the first half period after the ducks were introduced. Then it decreased rapidly as the rice plants grew in all plots. The contents of the suspended soil and turbidity in irrigation water were not changed over the free-ranging period, but $\textrm{NH}_3\textrm{-N}$ and $\textrm{P}_2\textrm{O}_5$ were decreased by intertillage and muddying by the ducks. There were no differences in both the soil physics and chemistry between the muddying plot and the control plot during and after finishing of the free-ranging period. These results indicate that intertillage and muddying by the ducks resulted in a small variation in stagnant water pH, and reduced the dissolved oxygen and $\textrm{P}_2\textrm{O}_5$, although the physiochemical properties of soil were not changed.

• Membrane Journal
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• v.24 no.5
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• pp.367-374
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• 2014

In the present study, disc-type LSCF/GDC (20 : 80 vol%) dual-phase membranes having porous LSC/GDC (50 : 50 vol%) active layers were prepared and effect of active layers on oxygen ion transport behavior was investigated. Introduction of active layers improved drastically oxygen flux due to enhanced electron conductivity and oxygen surface exchange activity. As firing temperature of active layer increased from $900^{\circ}C$ to $1000^{\circ}C$, oxygen flux increased due to improved contact between membrane and active layer or between grains of active layer. The enhanced contact would improve oxygen ion and electron transports from active layer to membrane. Also, as thickness of active layer increased from 10 to $20{\mu}m$, oxygen flux decreased since thick active layer rather prevented oxygen molecules diffusing through the pores. And, STF infiltration improved oxygen flux due to enhanced oxygen reduction reaction rate. The experimental data announces that coating and property control of active layer is an effective method to improve oxygen flux of dual-phase oxygen transport membrane.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.3
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• pp.241-247
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• 2013

Yellow clay dispersion has been applied to minimize fisheries impact by the red tide Cochlodinium polykrikoides blooms in Korean coasts since 1995. The present preliminary study documents the effect of yellow clay on Korean rockfish, Sebastes schlegelii, in terms of oxygen consumption rate (OCR). The OCR in the low clay suspension (0.05 and 0.23 %, w/w) showed normal level compared to the control. In contrast, the OCR for each one of three replicates in the high clay suspension (1.16 and 5.58 %, w/w) was not returned to the previous level that clay was not treated, indicating that high clay suspension (${\geq}1.16%$, w/w) might give negative effect on Korean rockfish. Overall, this result suggests that field application of clay to control Harmful Algal Blooms (HABs) may not give impact on Korean rockfish once the clay is dispersed in a low concentration (${\leq}0.23%$). In order to understand the changes of OCR in the repeated exposure to clay, it is required to do further studies on the changes of OCR when the fish is exposed to clay repeatedly after recovery in the normal seawater.

• Journal of the Korean Vacuum Society
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• v.18 no.6
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• pp.488-493
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• 2009

We developed a simple method to control the length of carbon nanotube array by using oxygen plasma etching. In this way, we could obtain a carbon nanotube with a uniform length (20, 30, 50, $70\;{\mu}m$), that was parallel to the substrate. Moreover, our growing method of carbon nanotube array gives a uniform diameter ~3.5nm, which is consistent with our previous results. Using the same etching method, we demonstrated the carbon nanotube radio frequency identification (RFID) antenna. The results could be useful for carbon nanotube applications such as flexible and transparent conductive films.

• Child Health Nursing Research
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• v.12 no.1
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• pp.75-83
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• 2006

Purpose: This study was done to verify the effect of roller acupuncture stimulation on baesu spots of joktaeyang bangkwang kyeong in the reaction to physiologic pain(heart rate, percutaneous oxygen saturation, respiration rate) in neonates. Method: This study was a nonequivalent control group non-synchronized design. The participants were 40 normal neonates who were born at a hospital in Busan. These neonates were undergoing heel puncture for blood type tests. The neonates were divided into 2 groups: 20 in the experimental group who were stimulated with roller acupuncture before the heel puncture and 20 neonates in the control group who were not stimulated. The heart rate and percutaneous oxygen saturation were measured using a cardiopulmonary monitor and the respiration rate was measured directly. The data were analyzed with SPSS 10.0 program using χ²-test, t-test and Repeated Measure ANOVA. Results: There was a significant difference (F=3.287, p=.043) for heart rate on the interaction between time and group. There was a significant difference (F=5.122, p=.008) for percutaneous oxygen saturation on the interaction between time and group. Conclusion: On the basis of results, it was verified that the roller acupuncture stimulation on baesu spots of joktaeyang bangkwang kyeong had effect of relieving pain in the neonates.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.257-262
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• 2002

Water-Electrolyzed gas is a mixed gas has the constant volume ratio 2 1 Hydrogen and Oxygen gained from electrolyzed water, and it has better characteristics in the field of economy, efficiency of energy, and environmental intimacy than acetylene gas and LPG used for existing gas welding equipment. So nowdays many studies of Water-Electrolyzed gas are progressed, and commercially used as a source of thermal energy for gas welding in the industry. For Water-Electrolyzed Source, it was used diode rectifier or SCR rectifier for get DC source. This method which is not looking to improve a source for impossible current control or voltage and limited control intervals. In this paper, it was relized and designed In source of pulse type for complementing existing - DC source type, also by experiment it was acquired producting characteristics of Hydrogen -Oxygen Gas through feature of source

• Journal of fish pathology
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• v.16 no.2
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• pp.91-102
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• 2003

The present study was investigated the effects of chlorine dioxide ($CIO_2$) on the rcspimtory metabolism of olive flounder (Parolichlhys olivaceus) imtermittently exposed to seawater chlorinated by $CIO_2$:. Oxygen consumption of flounder before and after once or twice $CIO_2$-treatment with 12 hr- or/and 24 hr-interval were serially measured with automatic intenniteent-flow respirometer system (AIRS). The oxygen consumption rates of flowKier exposed to 0.10 and 0.20 ppm$CIO_2$, were not different from the control fish prior to the once or twice chlorinations . On the other hand, the respiratory metabolic rates of flounder exposed to 0.30 ppm$CIO_2$ were significantly increased 15% and 22 - 23% after the once and twice chlorinations compared to the control fish. respectively. The flounder exposed In 0.40 and 0.50 ppm$CIO_2$: died within 4 hr and I hr. respectively. The elevation( respiratory metabolism in flounder exposed toO.30 ppm$CIO_2$ and above is considered due to physiological stress caused by $CIO_2$ exposure.

• Journal of Biomedical Engineering Research
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• v.17 no.1
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• pp.43-48
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• 1996

We investigated the energistics of the physiological heart model by comparing predictive indexes of the myocardial oxygen consumption (MOC), such as tension-time index (R), tension-time or force-time inteual (FTI), rate-pressure product (RPP), pressure-work index, and systolic pressure-volume area (PVA) when using the electro-hydraulic left ventricular device (LVAD). We developed the model of LVAD incorporated the closed-loop cardiovascular system with a baroreceptor which can control heart rate and time-varying elastance of left and right ventricles. On considering the benefit of the LVAD, the effects of various operation modes, especially timing of assistance, were evaluated using this coupled computer model. Overall results of the computer simulation shows that our LVAD can unload the ischemic (less contractile) heart by decreasing the MU and increasing coronary flow. Because the pump ejection at the end diastolic phase of the natural heart may increase the afterload of the left ventricle, the control scheme of our LVAD must prohibit ejecting at this time. Since the increment of coronary flow is proportional to the peak aortic pressure after ventricle contraction, the LVAD must eject immediately following the closure of the aortic valve to increase oxygen availability.