• The Korean Journal of Physiology
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• v.20 no.1
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• pp.53-63
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• 1986

Carbon monoxide(CO) poisoning has been one of the major environmental problems because of the tissue hypoxia, especially brain tissue hypoxia, due to the great affinity of CO with hemoglobin. Inhalation of the pure oxygen$(0_2)$ under the high atmospheric pressure has been considered as the best treatment of CO poisoning by the supply of $0_2$ to hypoxic tissues with dissolved from in plasma and also by the rapid elimination of CO from the carboxyhemoglobin(HbCO). Hydrogen peroxide $(H_2O_2)$ was rapidly decomposed to water and $0_2$ under the presence of catalase in the blood, but the intravenous administration of $H_2O_2$ is hazardous because of the formation of methemoglobin and air embolism. However, it was reported that the enema of $H_2O_2$ solution below 0.75% could be continuously supplied $0_2$ to hypoxic tissues without the hazards mentioned above. This study was performed to evaluate the effect of $H_2O_2$ enema on the elimination of CO from the HbCO in the recovery of the acute CO poisoning. Rabbits weighting about 2.0 kg were exposed to If CO gas mixture with room air for 30 minutes. After the acute CO poisoning, 30 rabbits were divided into three groups relating to the recovery period. The first group T·as exposed to the room air and the second group w·as inhalated with 100% $0_2$ under 1 atmospheric pressure. The third group was administered 10 ml of 0.5H $H_2O_2$ solution per kg weight by enema immediately after CO poisoning and exposed to the room air during the recovery period. The arterial blood was sampled before and after CO poisoning ana in 15, 30, 60 and 90 minutes of the recovery period. The blood pH, $Pco_2\;and\;Po_2$ were measured anaerobically with a Blood Gas Analyzer and the saturation percentage of HbCO was measured by the Spectrophotometric method. The effect of $H_2O_2$ enema on the recovery from the acute CO poisoning was observed and compared with the room air group and the 100% $0_2$ inhalation group. The results obtained from the experiment are as follows: The pH of arterial blood was significantly decreased after CO poisoning and until the first 15 minutes of the recovery period in all groups. Thereafter, it was slowly increased to the level of the before CO poisoning, but the recovery of pH of the $H_2O_2$ enema group was more delayed than that of the other groups during the recovery period. $Paco_2$ was significantly decreased after CO poisoning in all groups. Boring the recovery Period, $Paco_2$ of the room air group was completely recovered to the level of the before CO Poisoning, but that of the 100% $O_2$ inhalation group and the $H_2O_2$ enema group was not recovered until the 90 minutes of the recovery period. $Paco_2$ was slightly decreased after CO poisoning. During the recovery Period, it was markedly increased in the first 15 minutes and maintained the level above that before CO Poisoning in all groups. Furthermore $Paco_2$ of the $H_2O_2$ enema group was 102 to 107 mmHg and it was about 10 mmHg higher than that of the room air group during the recovery period. The saturation percentage of HbCO was increased up to the range of 54 to 72 percents after CO poisoning and in general it was generally diminished during the recovery period. However in the $H_2O_2$ enema group the diminution of the saturation percentage of HbCO was generally faster than that of the 100% $O_2$ inhalation group and the room air group, and its diminution in the 100% $O_2$ inhalation group was also slightly faster than that of the room air group at the relatively later time of the recovery period. In conclusion, the enema of 0.5% $H_2O_2$ solution is seems to facilitate the elimination of CO from the HbCO in the blood and increase $Paco_2$ simultaneously during the recovery period of the acute CO poisoning.

• Journal of the Korean Institute of Gas
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• v.27 no.3
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• pp.59-71
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• 2023

Carbon capture, and storage (CCS) is important for the reduction of greenhouse gases and achieving carbon neutrality. CCS focuses on storing captured CO₂ permanently in underground reservoirs. CO₂-enhanced oil recovery (CO₂-EOR) is one form of CCS, where CO₂ is injected into the underground to enhance oil recovery. CO₂-EOR not only aids in the extraction of residual oil but also contributes to carbon neutrality by storing CO₂ underground continuously. CO₂-EOR can be classified into miscible and immiscible methods, with the CO₂-water alternating gas (CO₂-WAG) technique being a representative approach within the miscible method. In CO₂-WAG, water and CO₂ are alternately injected into the reservoir, enabling oil production and CO₂ storage. The WAG method allows for controlling the breakthrough of injection fluids, providing advantages in oil recovery. It also induces hysteresis in relative permeability during the injection and production process, expanding the amount of trapped CO₂. In this study, the effects of enhancing oil recovery and storing CO₂ underground during CO₂-EOR were presented. Additionally, cases of CO₂-EOR application in relation to CCS were introduced.

• Journal of Information Display
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• v.2 no.4
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• pp.63-67
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• 2001

The switching power loss due to the panel capacitance during sustain period in AC PDP driving system can be minimized by using the energy recovery circuits. We proposed a new energy recovery circuit, SER1 (Seoul national univ. Energy Recovery circuit 1st). The experimental results of its application to a 42-inch surface discharge type AC PDP showed superior performance of SER1 in energy recovery efficiency and low distortion voltage waveform. Energy recovery efficiency of SER1 was measured up to 92.3 %, and the power dissipation during the sustain period was reduced by 15.2 W in 2000 pulse/frame compared with serial LC resonance energy recovery circuit.

• Journal of the Korean Institute of Gas
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• v.21 no.2
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• pp.1-9
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• 2017

Enhanced coalbed methane recovery (ECBM), as injecting $CO_2$ or $N_2$ into the coalbed methane (CBM) reservoir for increasing methane recovery, takes center stage in these days. ECBM makes a better recovery than the conventional production method, it called dewatering process. However the characteristics of injection gas affect to methane recovery, thus analysis on the mixed ratio of injection gas should be required. In this study, CBM reservoir model was built to estimate the methane recovery of ECBM method by different mixed ratio of injection gas. Additionally, to consider the characteristics of injection gas such as carbon captured storage, nitrogen re-injection, etc. economic analysis was performed. The results showed that ECBM cases produced methane almost twice as much as dewatering case and $CO_2$ 10% and $N_2$ 90% case resulted in the highest methane recovery among the mixed gas cases. On the other hand, the results of economic analysis showed that $CO_2$ 20% and $N_2$ 80% case made the highest total production profit. Therefore, both the recovery of methane and economical efficiency should be considered to apply ECBM process.

• The Korean Journal of Food And Nutrition
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• v.12 no.4
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• pp.358-363
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• 1999

This study was conducted to evaluate the extraction methods for the determination of antioxidants in soybean oil. Recovery rates of various antioxidants in soybean oil showed similar rates as 80.4~102.1% by solvent/solvent extraction method and 89.9~106.4% by sweep co-distillation method except 46.6~61.2% of PG at corresponding spiked concentractions. The maximun recovery rates of antioxidnts were obtained when extraction time and extraction temperature used in UNITREX were 20min and 21$0^{\circ}C$ respectively. In the recovery rates with the activation of florisil when 2% ofwater was added to florisil the highest recovery rates for TBHQ, BHA, BHT were obtained by sweep co-distillation met-hod. Therefore sweep co-distillation method showed less solvent simple operation and high recovery rate compared with solvent/solvent extraction method.

• Journal of Powder Materials
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• v.23 no.5
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• pp.372-378
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• 2016

This study focuses on the development of an alkaline leaching hydrometallurgy process for the recovery of tungsten from WC/Co hardmetal sludge, and an examination of the effect of the process parameters on tungsten recovery. The alkaline leaching hydrometallurgy process has four stages, i.e., oxidation of the sludge, leaching of tungsten by NaOH, refinement of the leaching solution, and precipitation of tungsten. The WC/Co hardmetal sludge oxide consists of $WO_3$ and $CoWO_4$. The leaching of tungsten is most affected by the leaching temperature, followed by the NaOH concentration and the leaching time. About 99% of tungsten in the WC/Co hardmetal sludge is leached at temperatures above $90^{\circ}C$ and a NaOH concentration above 15%. For refinement of the leaching solution, pH control of the solution using HCl is more effective than the addition of $Na_2S{\cdot}9H_2O$. The tungsten is precipitated as high-purity $H_2WO_4{\cdot}H_2O$ by pH control using HCl. With decreasing pH of the solution, the tungsten recovery rate increases and then decrease. About 93% of tungsten in the WC/Co hardmetal sludge is recovered by the alkaline leaching hydrometallurgy process.

• Journal of Power System Engineering
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• v.18 no.4
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• pp.52-59
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• 2014

The purpose of this study is to evaluate the performance of after-treatment equipment and thermal storage devices for a heat recovery and combustor-type $CO_2$ generator fuelled a kerosene. To reduce the levels of harmful exhaust gases produced by a $CO_2$ generator, a catalyzed particulate filter(CPF) has been selected as an after-treatment device, by considering back pressure and exhaust gas temperature. The CO conversions of the catalyzed SiC filter(full plugging) were 92%, and the concentration of PM(particulate matter) was near ambient. A thermal recovery device was used to recover 13% of the heat energy from the exhaust gas through heat exchangers installed on the exhaust line of the $CO_2$ generator. 69% of the moisture within the exhaust gases was removed by condensing water, in order to minimize excessive humidity within the greenhouse.

• Applied Chemistry for Engineering
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• v.25 no.3
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• pp.262-267
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• 2014

SAGD (steam assisted gravity drainage) process is the most commonly used in-situ technology for the recovery of bitumen from oil sand. It was investigated that the effects of different additives on bitumen recovery rate from oil sand in SAGD process among many possible mechanisms studied throughout the study. Bitumen recovery from thin layer oil sand reservoirs was simulated by using an experimental SAGD apparatus with scale of 150:1. To improve the simulation accuracy of thin layer oil reservoir, we have attached geological model (GM). Oil sand was simulated by using a mixture of extra heavy oil and glass beads with a diameter of 1.5 mm. $CO_2$ was used as an additive and the evolution of steam chambers were closely monitored, and the effects of $CO_2$ as an additive was investigated. Two types of injection methods were tested; continuous ($cCO_2$-SAGD) and sequential interruption ($sCO_2$-SAGD) $CO_2$ injection. For the $sCO_2$-SAGD experiment, it was observed that the recovery rates and CSOR were efficiently improved control experiment from 60.2% to 69.3% and 7.1 to 6.0, respectively, whereas $cCO_2$-SAGD experiment decreased from 60.2% to 57.6% and 7.1 to 7.3.

• Journal of Electrical Engineering and Technology
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• v.11 no.4
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• pp.969-973
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• 2016

Interruption tests were conducted using the same circuit breaker for an initial pressure of SF₆ 0.5 MPa (gauge pressure) and CO₂ mixture 1.0 MPa, 0.8 MPa, and 0.6 MPa. The pressure-rises in the compression and thermal expansion chambers were measured for verifying the computational results using a simplified synthetic test facility. Further, the possibility of the CO₂ mixture substituting SF₆ gas was confirmed. Moreover, in view of the thermal recovery capability, it has also been confirmed that the pressure of the CO₂ mixture can be reduced almost to the same value as that of the SF₆ gas by optimizing the design parameters of the interrupter.

• Korean Journal of Materials Research
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• v.18 no.12
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• pp.650-654
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• 2008

The emission of carbon dioxide from the burning of fossil fuels has been identified as a major contributor to green house emissions and subsequent global warming and climate changes. For these reasons, it is necessary to separate and recover $CO_2$ gas. A new process based on gas hydrate crystallization is proposed for the $CO_2$ separation/recovery of the gas mixture. In this study, gas hydrate from $CO_2/H_2$ gas mixtures was formed in a semi-batch stirred vessel at a constant pressure and temperature. This mixture is of interest to $CO_2$ separation and recovery in Integrated Coal Gasification (IGCC) plants. The impact of tetrahydrofuran (THF) on hydrate formation from the $CO_2/H_2$ was observed. The addition of THF not only reduced the equilibrium formation conditions significantly but also helped ease the formation of hydrates. This study illustrates the concept and provides the basic operations of the separation/recovery of $CO_2$ (pre-combustion capture) from a fuel gas ($CO_2/H_2$) mixture.