• Journal of Hydrogen and New Energy
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• v.19 no.4
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• pp.291-298
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• 2008

Carbon monoxide(CO) is one of the contamination source in reformed hydrogen fuel with an influence on performance of polymer electrolyte membrane fuel cell(PEMFC). The studies of CO injection presented here give information about poisoning and recovery processes. The aim of this research is to investigate cell performance decline due to carbon monoxide impurity in hydrogen. Performance of PEM fuel cell was investigated using current vs. potential experiment, long time(10 hours) test, cyclic feeding test and electrochemical impedance spectra. The concentrations of carbon monoxide were changed up to 10 ppm. Performance degradation due to carbon monoxide contamination in anode fuel was observed at high concentration of carbon monoxide. The CO gas showed influence on the charge transfer reaction. The performance recovery was confirmed in long time test when pure hydrogen was provided for 1 hour after carbon monoxide had been supplied. The result of this study could be used as a basis of various reformation process design and fuel quality determination.

• Korean Journal of Pharmacognosy
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• v.16 no.2
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• pp.81-92
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• 1985

The Polygoni Radix and Cynanchi Radix have been used to potentiate the liver functions in clinic of Oriental Medicine. The water extracts of Polygoni Radix and Cynanchi Radix were administered orally to rats intoxicated with carbon tetrachloride and then this experiment have been performed by observing liver fatty degeneration and activities of enzymes such as cytochrome oxidase (CYO), adenosine triphosphatase (ATP), acid phosphatase (ACP), lactate dehydrogenase (LDH) and alkaline phosphatase (ALP). By oral administration of water extracts of the radices between 1 and 10 days, the following results were obtained. 1. The group given Cynanchi Radix extract showed recovery of the fat liver in 4 days, whereas that given Polygoni Radix extract did the recovery in 8 days. 2. In cytochrome oxidase activity, the group given Cynanchi extract showed normal activity in 6 days, whereas that given Polygoni Radix extract did the activity in 8 days. 3. In adenosine triphosphatase activity, the groups given Cynanchi Radix and Polygoni Radix extracts showed normal activities in 2 and 8 days, respectively. 4. In acid phosphatase activity, the groups given Cynanchi Radix and Polygoni Radix extracts showed recovery of the activities in 2 and 4 days, respectively. 5. In lactate dehydrogenase activity, the group given Cynanchi Radix and Polygoni Radix extracts showed recovery of the activities in 6 and 10 days, respectively. 6. In alkaline phosphatase activity, the group given Cynanchi Radix extract showed normal activity in 2 days, whereas that given Polygoni Radix extract showed slight recovery between 4 and 6 days followed by decrease of the activity in 8 and 10 days. From the above-mentioned results, it was found that both of the water extracts of Polygoni and Cynanchi Radix possessed the recovery action of liver function as intoxicated with carbon tetrachloride in rats. It is also noted that the extract of Cynanchi Radix showed more potent activity than that of Polygoni Radix.

• Resources Recycling
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• v.31 no.6
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• pp.3-17
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• 2022

The cement industry, which is an energy-intensive and high carbon dioxide emission industry, requires strategy for carbon neutrality and sustainable development. Most domestic cement companies are generating electricity by waste heat recovery system to improve energy efficiency during cement processes; however, few studies exist on recycling of energy related to this. Certain countries with high cement production researched on modifying the conventional waste heat recovery system to maximize waste heat recovery using various methods such as applying the Rankine cycle depending on the temperature, comparing working fluids, applying two or more Rankine cycles, and combining with other industries. In this study, we reviewed the research direction for energy efficiency improvement by summarizing waste heat recovery and utilization methods in the domestic and overseas cement industries.

• Environmental Engineering Research
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• v.22 no.2
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• pp.169-174
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• 2017

Vacuum swing adsorption (VSA) is a promising treatment method for volatile organic compounds (VOCs). This study focuses on a VSA process for regenerating activated carbon spent with VOCs, and then investigates its adsorption capacities. Toluene was selected as the test VOC molecule, and the VSA regeneration experiments results were compared to the thermal swing adsorption process. Cyclic adsorption-desorption experiments were performed using a lab-scale apparatus with commercial activated carbon (Samchully Co.). The VSA regeneration was performed in air (0.5 L/min) at 363.15 K and 13,332 Pa. The comparative results depicted that in terms of VSA regeneration, it was found that after the fifth regeneration, about a 90% regeneration ratio was maintained. These experiments thus confirm that the VSA regeneration process has good recovery while operating at low temperatures (363.15 K) and 13,332 Pa.

• Journal of Forest and Environmental Science
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• v.32 no.3
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• pp.302-310
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• 2016

The loss and degradation in tropical forest region are some of the current global concern. Hence, these issues elevated the role of rehabilitated forests in providing ecological products and services. The information on the carbon stock is important in relation to global carbon and biomass use, but lacking from the tropical region. This paper reports the assessment of tree and soil carbon stock in a chronosequence rehabilitated tropical forest stands in Malaysia. The study site was at the UPM-Mitsubishi Forest Rehabilitation Project, UPMKB. $20{\times}20m$ plot was established each and assessed in 2009 at 1-, 10- and 19-year-old sites while an adjacent ${\pm}23-year-old$ natural regenerating secondary forest plot was established for comparison. The overall total carbon stock was in the order of 19-year-old>${\pm}23-year-old$>10-year-old>1-year-old. When forest carbon stock is low, the soil component plays an important role in the carbon storage. The forest carbon recovery is crucial to increase soil carbon stock. The variations in the carbon stock showed the different stages of the forest recovery. Species survived after 19-years of planting are potential species for carbon sequestration activities in rehabilitated forest. Human intervention in rehabilitating degraded forest areas through tree planting initiatives is crucial towards recovering the forest ecological role especially in forest carbon stock capacity.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.11
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• pp.627-634
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• 2016

We investigated the characteristics of heavy metal desorption and recovery from carbon foam after plating wastewater treatment. The heavy metal desorption depends on solution chemistry because desorption occurred in HCl and $H_2SO_4 $ solution but did not occur in distilled water. Heavy metal desorption efficiency was increased using ultrasonication with desorption solution. The higher ultrasonic power and the longer reaction time improve efficiency. The copper plating rinse solution was treated reliably by carbon foam adsorbent during 200 bed volume. The adsorbed copper was dissolved using desorption solution and recovered by DC power supply. After copper recovery, the reuse efficiency of desorption solution was 84.2%.

• Membrane Journal
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• v.33 no.6
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• pp.344-351
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• 2023

The membrane separation process for carbon dioxide capture from hydrogen reformer exhaust gas has been developed. Using a commercial membrane module, a multi-stage process was developed to achieve 90% of carbon dioxide purity and 90% of recovery rate for ternary mixed gas. Even if a membrane module with being well-known properties such as material selectivity and permeability, the process performance of purity and recovery widely varies depending on the stage-cut, the pressure at feed and permeate side. In this study, we verify the limits of capture efficiency at single-stage membrane process under various operating conditions and optimized the two-stage recovery process to simultaneously achieve high purity and recovery rate.

• Journal of Chest Surgery
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• v.25 no.12
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• pp.1391-1398
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• 1992

The hypothesis tested is that shifts in pH, induced when a cardioplegic solution is oxygenated, can be detrimental. The object of this study is to evaluate the effect of the pH of the oxygenating cardioplegic solution on postischemic recovery in the isolated rat heart. Either 100% oxygen or 95% oxygen: 5% carbon dioxide was added to the cardioplegic solution[St. Thomas` Hospital No. 2] and determined postischemic recovery of isolated rat hearts after 2 hours and 3 hours of 20oC cardioplegic protected ischemia. Heart were arrested and reinfused every 30 minutes throughout the ischemic period with cardioplegic solution. When 100% oxygen was added, the pH of the cardioplegic solution increased from 7.8[no oxygen] to 8.5[100% oxygen] without any change in postischemic functional recovery. But when 95% oxygen ; 5% carbon dioxide was added, the pH of the cardioplegic solution reversely decreased to 6.84 in the 2-hour ischemic group and 6.73 in the 3-hour ischemic group, associated with improved postischemic functional recovery. After 2-hour ischemia, systolic pressure improved from 88.2$\pm$3.7%[no oxygen] and 88.7$\pm$3.8%[100% oxygen] to 96.6$\pm$1.8%[95% oxygen : 5% carbon dioxide], p<0.05, aortic flow from 43.3$\pm$3.1% and 38.4$\pm$10.6% to 74.5$\pm$5.0%, p<0.001, cardiac output from 55.5$\pm$4.6% and 47.4%$\pm$10.6% to 73.1$\pm$4.6%, p<0.05, stroke volume from 62.7$\pm$4.6% and 52.0$\pm$10.1% to 77.2$\pm$4.6%, p<0.05, and dP/dT from 59.3$\pm$7.2% and 56.7$\pm$7.6% to 78.9$\pm$4.6%, p<0.05. The infused amount of the cardioplegic solution during 2-hour ischemic period was similar in three groups. After 3-hour ischemia, cardiac output improved from 17.0$\pm$3.8%[no oxygen] to 45.9$\pm$7.5%[95% oxygen: 5% carbon dioxide], p<0.05, and stroke volume from 21.0$\pm$3.9%[no oxygen] to 50.1$\pm$6.6%[95% oxygen: 5% carbon dioxide], p<0.01. In conclusion, the St. Thomas` Hospital No. 2 cardioplegic solution should be oxygenated but with 95% oxygen: 5% carbon dioxide and not 100% oxygen because of the additive effect of a relatively "Acidotic" pH.t; pH.

• Journal of Korean Society of Water and Wastewater
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• v.12 no.3
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• pp.30-40
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• 1998

Increasing water consumption produced sludge problems of the water treatment plants. The objective of this study is to investigate aluminium coagulants recovery n acidic and alkaline conditions. Water treatment plant sludge produced in Pusan Metropolitan City were tested for the aluminium extraction process. Experiment samples were obtained in summer from water treatment plants of Deoksan and Myongjang. Aluminium coagulants used in these plants during the test period were polyaluminium chloride(PAC), polyaluminium sulfate organic(PSO), polyaluminium sulfate silicate(PASS). Aluminium contents of water treatment sludge were in the range of 7.2~10.9% of the total solids. The recovery percentages for aluminium and iron by acidic extraction method was evaluated to 88% and 42% respectively. Extracted mass variation for other materials such as iron, manganese, total organic carbon was observed during the extraction operation. Alkaline extraction produced more than two times amount of total organic carbon than that in the acidic extraction process.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.67-70
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• 2014

We performed computational simulation for a heat recovery steam generator to predict emissions (especially carbon monoxide) and compare the results with experimental data. We used the steady laminar flamelet model(SLFM) which can consider detailed chemical mechanisms. To reduce the number of grid, we simplified the geometry of the whole heat recovery steam generator. In conclusion, the trend of simulation results is good agreement with experimental data.