• Journal of Korean Society for Atmospheric Environment
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• v.24 no.2
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• pp.153-161
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• 2008

The guidelines for indoor air quality of public transportations such as subway, train and bus was presented by Korean Ministry of Environment last end of year 2006 based on the great consequence of indoor air quality in daily life. Two main parameters, carbon dioxide($CO_2$) and particulate matters smaller than $10\;{\mu}m(PM_{10})$, were selected as index pollutants for the management of indoor air quality. The former pollutant, $CO_2$, is regarded as index of ventilation status and the major source of $CO_2$ in the train or subway is the exhalation of passengers. It is publically perceived that the high $CO_2$ concentration in a crowded subway will be reduced and ventilated with outdoor air by door-opening taken every 2 or 3 minutes when the train stops each station. However, there has not been any scientific proof and quantitative information on the effect of door-opening on the $CO_2$ reduction by ventilation with outdoor air. In this study, $CO_2$ concentration and number of passengers were measured at each station on the 3 lines of Korail metropolitan subway. In order to evaluate the effect of $CO_2$ reduction by door opening, the theoretical approach using the $CO_2$ balance equation was performed. By comparing the predicted data with monitoring one, the optimum $CO_2$ dilution factor was determined. For the first time, it was quantified that about 35% of $CO_2$ concentration in the subway indoor was removed by the door-opening at each station.

• Computational Structural Engineering
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• v.24 no.1
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• pp.14-21
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• 2011

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.2
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• pp.232-241
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• 2016

The turbocharger, to decrease the harmful exhaust gas(CO, HC and etc.) and $CO_2$ emission as well as the increase of the engine output, would be an useful method for engine downsizing. Therefore the thermal endurance of turbine blade, the lubrication of turbine shaft and the engine knock according to the supercharge of the inlet air, had been studied. And there had been much progress in these research tasks to be achieved a breakthrough. But a study on the built-in WGV of a gasoline engine for a passenger car which may effect on the engine performance, is few. In this paper, the effect of the embedded WGV on the engine performance was performed through the endurance test, which was conducted more than 300 hrs using the 4 stroke, 1998 cc, water-cooled engine. To sum up the major results, there were an abrasion in the area of the WGV head edge and the thermal deformation on the WGV head face, These phenomena led to reducing the boost pressure which caused the reduction in the volumetric efficiency of the engine. It resulted in decreasing the engine power gradually during the life cycle of the embedded WGV.

• Microbiology and Biotechnology Letters
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• v.13 no.1
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• pp.27-31
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• 1985

A rapid assay for interferon based on reduction of cytopathic effect was developed with HEp-2 and Vesicular Stomatitis Virus. The number of manipulations and the lengths of the various incubation steps were reduced to minimum. The assay is simple to perform and can be completed with 22-24 hr. Moreover, it was precise method than CPE-reading method.

• Bulletin of the Korean Chemical Society
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• v.17 no.3
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• pp.223-227
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• 1996

Catalytic effects of transition metal (Co2+, Ni2+) complexes of N,N-bis(salicylaldehyde)-o-phenylenediimine (SOPD), N,N-bis(salicylaldehyde)-m-phenylenediimine (SMPD), and N,N-bis(salicylaldehyde)-p-phenylenediimine (SPPD), on the reduction of thionyl chloride at glassy carbon electrode, are evaluated by determining the kinetic parameters with cyclic voltammetric technique. The charge transfer process for the reduction of thionyl chloride is strongly affected by the concentration of the catalysts. Some quadridentate Schiff base-M(Ⅱ) complexes show sizable catalytic activities for the reduction of thionyl chloride. Catalytic effects of [M(Ⅱ)(SOPD)] complexes are slightly larger compared to [M(Ⅱ)2(SMPD)2] and [M(Ⅱ)2(SPPD)2] complexes. On those electrodes deposited with the catalysts, the observed exchange rate constants (ko) are in the range of 0.89-2.28 × 10-7 cm/s, while it is 1.24 × 10-7 cm/s on the bare glassy carbon electrode.

• Environmental and Resource Economics Review
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• v.22 no.3
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• pp.459-479
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• 2013

To assess the feasibility of 'low carbon, sustainable growth' policy pursued of the Chinese government, this paper first measures technical efficiency, $CO_2$ shadow prices, and indirect Morishima elasticity of substitution between capital and energy for 24 of manufacturing sectors in Beijing and Chongqing, in which China launched pilot carbon emissions trading scheme, by estimating the input distance function. Based on these results, then the potential for $CO_2$ reduction, cost savings from emissions trading, and the effectiveness of capital investment in reducing $CO_2$ are compared across industries and provinces. In 2010, manufacturing industries in Beijing and Chongqing could potentially reduce the largest $CO_2$ emissions, amounting 5.2 and 17 million tons, respectively, by achieving 100% technical efficiency. While, on average, Chongqing has a comparative advantage in the cost savings from carbon trading over Beijing, Beijing is more likely to reduce $CO_2$ by expanding capital investment.

• Transactions of the Korean hydrogen and new energy society
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• v.14 no.1
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• pp.24-34
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• 2003

For gaseous fuel combustion with inherent $CO_2$ capture and low NOx emission, chemical-looping combustion may yield great advantages for the savings of energy to $CO_2$ separation and suppressing the effect on environment, In chemical-looping combustor, fuel is oxidized by metal oxide medium in a reduction reactor. Reduced particles are transported to oxidation reactor and oxidized by air and recycled to reduction reactor. The fuel and the air are never mixed, and the gases from reduction reactor, $CO_2$ and $H_2O$, leave the system as separate stream. The $H_2O$ can be easily separated by condensation and pure $CO_2$ is obtained without any loss of energy for separation. In this study, five oxygen carrier particles such as NiO/bentonite, NiO/YSZ, $(NiO+Fe_2O_3)VYSZ$, $NiO/NiAl_2O_4$, and $Co_{\chi}O_y/CoAl_2O_4$ were examined &om the viewpoints of reaction kinetics, oxygen transfer capacity, and carbon deposition characteristics. Among five oxygen particles, NiO/YSZ particle is superior in reaction rate, oxygen carrier capacity, and carbon deposition to other particles. However, at high temperature ($>900^{\circ}C$), NiO/bentonite particle also shows enough reactivity and oxygen carrier capacity to be applied in a practical system.

• Clean Technology
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• v.24 no.1
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• pp.35-40
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• 2018

$Co_3O_4$ catalysts for $N_2O$ decomposition were prepared by co-precipitation method. Ce and Zr were added during the preparation of the catalyst as promoter with the molar ratio (Ce or Zr) / Co = 0.05. Also, 1 wt% $K_2CO_3$ was doped to the prepared catalyst with impregnation method to investigate the effect of K on the catalyst performance. The prepared catalysts were characterized with SEM, BET, XRD, XPS and $H_2-TPR$. The $Co_3O_4$ catalyst exhibited a spinel crystal phase, and the addition of the promoter increased the specific surface area and reduced the particle and crystal size. It was confirmed that the doping of K improves the catalytic activity by increasing the concentration of $Co^{2+}$ in the catalyst which is an active site for catalytic reaction. The catalytic activity tests were carried out at a GHSV of $45,000h^{-1}$ and a temperature range of $250{\sim}375^{\circ}C$. The K-impregnated $Co_3O_4$ catalyst showed much higher activity than $Co_3O_4$ catalysts with promoter only. It is found that the K-impregnation increased the concentration of $Co^{2+}$ more than the added of promoter did, and lowered the reduction temperature to a great extent.

• Transactions of the Korean hydrogen and new energy society
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• v.24 no.3
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• pp.255-263
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• 2013

Carbon dioxide reduction technologies using photosynthetic microorganism were suggested to overcome environmental destruction caused by $CO_2$ in flue gases from power plant and other industries. However, there are many toxic constituents in flue gas including CO, NOx, SOx. Continuous and Excessive supply of these noxious gases to cells will leads to inhibition of microalgal growth along with partial cell death. In this study, we tested the noxious effect of SOx and NOx on the pH and microalgal growth under photoautotrophic culture in three microalgae of Neochloris oleoabundans, Chlorella vulgaris and Haematococcus pluvialis. As a result, SOx concentration more than 50 ppm led to the rapid reduction of pH, thereby inhibiting of the growth in Neochloris oleoabundans and Chlorella vulgaris. NOx concentration more the 100 ppm reduced the exponential growth of N. oleoabundans and C. vulgaris. And H. pluvialis exhibited low sensitivity to SOx and NOx. Consequently, the three microalgae of N. oleabundas, C. vulagaris and H. pluvialis showed the normal vegetative growth in 25 ppm of NOx and SOx. Above all, H. pluvialis was useful for the $CO_2$ sequestration of the flue gas including high concentrations of NOx and SOx.

• Applied Chemistry for Engineering
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• v.28 no.1
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• pp.112-117
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• 2017

This study demonstrated the emission of combustion gases of medium density fibreboard (MDF)s coated with piperazinomethyl-bis-phosphonic acid (PIPEABP), methylpiperazinomethyl-bis-phosphonic acid (MPIPEABP), N,N-dimethylethylenediaminomethyl-bis-phosphonic acid (MDEDAP), or bis-(dimethylaminomethyl) phosphinic acid (DMDAP). Each MDFs were coated in three times with a brush with 15 wt% aqueous solution of the phosphorus-nitrogen acid additives. After the specimens were dried at room temperature, the emission of combustion gases was tested using a cone calorimeter (ISO 5660-1, 2). The peak smoke production rate ($SPR_{peak}$) of the specimens coated with phosphorus-nitrogen acids was 18.5 to 41.5%, which is lower than that of using the virgin plate. However, the production of peak carbon monoxide ($CO_{peak}$) was 6.7 to 24.2% higher than that of using the virgin plate. Also, the peak carbon dioxide ($CO_{2peak}$) was 4.2 to 24.4% lower than that of using virgin plate. While the peak oxygen depletion rate was much higher than the level of 15%, which can be fatal to humans and the resulting risk could thus be eliminated. Overall, the combustibility of coated specimens was partially suppressed, but showed a negative effect on the reduction of carbon monoxide.