• Journal of Korea Soil Environment Society
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• v.4 no.2
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• pp.185-192
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• 1999

To assess the soil quality of Chonan City, soil analyses were conducted according to the 14 different sampling sites. The soil pH of the agricultural area near the expressway was lower than that of the other farming area, which indicated that this acidification was probably attributed to the acid rain caused by the traffic exhaust gas such as SOx and NOx. Acidification was more severe in the dry farming area than in the rice paddy area. All concentration of 6 different heavy metals (As, Cu, Cd, $Cr^{6+}$, Hg, Pb) and organic contaminants (cyanide, organic-p, PCBs, phenols) were found to be lower than the standard of soil pollution. The concentration of BTEX also lower than the standard of soil pollution. An assessment using the SPI (Soil Pollution Index). which was developed to estimate an overall soil quality, was performed. Each SPC (Soil Pollution Score) were evaluated with the results of the data from this study. The soil quality of most area of Chonan City was determined to Class 1 , which indicated that the soil was healthy.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.105-105
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• 2011

ZnO is a promising material since it could be applied to many fields such as solar cells, laser diodes, thin films transistors and gas sensors. ZnO has a wide and direct band gap for about 3.37 eV at room temperature and a high exciton binding energy of 60 meV. In particular, ZnO features high sensitivity to toxic and combustible gas such as CO, NOX, so on. The development of gas sensors to monitor the toxic and combustible gases is imperative due to the concerns for enviromental pollution and the safety requirements for the industry. In this study, we investigated the effect of substrate temperature and post-annealing on structural and electrical properties of ZnO thin films. ZnO thin films were deposited by pulsed laser deposition (PLD) at various temperatures at from room temperature to $600^{\circ}C$. After that, post-annealing were performed at $600^{\circ}C$. To inspect the structural properties of the deposited ZnO thin films, X-ray diffraction (XRD) was carried out. For gas sensors, the morphology of the films is dominant factor since it is deeply related with the film surface area. Therefore, the atomic force microscopy (AFM) and field emission scanning electron microscopy (FE-SEM) were used to observe the surface of the ZnO thin films. Furthermore, we analyzed the electrical properties by using a Hall measurement system.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.3
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• pp.90-101
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• 2009

An objective of this study is to suggest a procedure to evaluate vehicle emissions regardless of the driving pattern. Field experiments using portable emission measurement system were conducted under the real world driving cycle. Standardized average for NOx, $CO_2$ emission and fuel consumption rates were calculated while the vehicle specific power distribution within each vehicle speed bin was taken into consideration. Composite emission factor and fuel economy, which were obtained based on the standardized average results and traffic statistics, showed good similarity to those acquired through the conventional chassis dynamometer tests qualitatively as well as quantitatively. Considering that a conventional method obviously has a limitation to reflect various characteristics of the real world, the new approach suggested in this study can be used as an alternative procedure to collect more specific data to establish the mobile emission factors.

• Environmental and Resource Economics Review
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• v.17 no.1
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• pp.121-146
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• 2008

The purpose of this paper IS to estimate efficiency and loss of productivity under environmental regulation, and analyze the environmental efficiency index empirically. Using the panel data for 20 member countries of OECD during 1985~1999, environmental efficiency index can be constructed by comparing the production processes under alternative assumptions of disposability, by using a hyperbolic measure of productive efficiency. As a result of estimation for the environmental efficiency index, EE of OECD countries gradually shows a downward trend. In terms of the treatment of pollutants, Japan, Germany and France are countries that have a considerable burden in getting rid of the pollutants. In case of EE, Korea displayed high environment efficiency, but in the latter half of the 1990's, the environmental efficiency of Korea became slightly worse. During the same period, Korea had a burden in dealing with NOx just like the other OECD countries.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.5
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• pp.604-613
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• 2006

The chemical composition of $PM_{2.5}$ such as ${SO_4}^{2-},\;{NO_3}^-,\;Cl^-,\;{NH_4}^+,\;Ca^{2+},\;K^+,\;Na^+,\;Mg^{2+}$, OC, and EC and the concentrations of reactive trace gases including $O_3,\;CO,\;NOx,\;SO_2,\;and\;H_2O_2$ were measured at Gosan in Jeju Island during March $13{\sim}30$, as a part of the Atmospheric Brown Clouds-East Asian Regional Experiment 2005(ABC-EAREX2005). The average mass concentrations of $PM_{2.5}$ was 27.3 ${\mu}g/m^3$, of which OC showed the highest concentration as 4.22 ${\mu}g/m^3$ and nss ${SO_4}^{2-}$ was the second highest as 3.34 ${\mu}g/m^3$. During that period, average concentrations of CO and $O_3$ was about 300 ppbv and 56 ppbv, respectively. For the whole experiment, the correlations of CO with ${SO_4}^{2-}$ and EC were very good, which suggests that CO can be used as tracer for the formation of fine aerosols. Several pollution and dust episodes were identified by the enhancement of CO, OC, EC, nss ${SO_4}^{2-},\;or\;Ca^{2+}$ concentrations or their ratios. In conjunction with factor analysis, air trajectory analysis, and comparison with emission inventories, these results indicate the spring aerosols collected at Gosan was strongly influenced by Asian outflows.

• Applied Chemistry for Engineering
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• v.24 no.6
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• pp.599-604
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• 2013

In this study, Ti added Mn-Cu mixed oxide catalysts were prepared by a co-precipitation method and used for the low temperature (< $200^{\circ}C$) selective catalytic reduction (SCR) of NOx with $NH_3$. Physicochemical properties of these catalysts were characterized by BET, XRD, XPS, and TPD. Mn-Cu mixed oxide catalysts were found to be amorphous with a large surface and they showed high SCR activity. Experimental results showed that the addition of $TiO_2$ to Mn-Cu oxide enhanced the SCR activity and $N_2$ selectivity. Ti addition led to the chemically adsorbed oxygen species that promoted the oxidation of NO to $NO_2$ and increased the number of $NH_3$ adsorbed-sites such as $Mn^{3+}$.

• Applied Chemistry for Engineering
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• v.28 no.1
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• pp.64-72
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• 2017

A series of Pt-based ${\gamma}-Al_2O_3$ catalysts promoted with several alkali and alkaline earth metals were prepared by a wet impregnation method. We confirmed that the addition of Na to $Pt/{\gamma}-Al_2O_3$ could cause a change in the oxidation state of Pt through an electronegative gap between Pt and Na atom, and increase the ratio of the metallic Pt. The metallic Pt species made by adding an optimum Na content improved the adsorption of NO species on the catalyst surface and restrained the oxidation of $CH_4$ to $CO_2$. When molar ratio of Na/Pt was 4.0, the highest catalytic activity could be obtained.

• Genomics & Informatics
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• v.16 no.3
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• pp.59-64
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• 2018

Although pork quality traits are important commercially, genome-wide association studies (GWASs) have not well considered Landrace and Yorkshire pigs worldwide. Landrace and Yorkshire pigs are important pork-providing breeds. Although quantitative trait loci of pigs are well-developed, significant genes in GWASs of pigs in Korea must be studied. Through a GWAS using the PLINK program, study of the significant genes in Korean pigs was performed. We conducted a GWAS and surveyed the gene ontology (GO) terms associated with the backfat thickness (BF) trait of these pigs. We included the breed information (Yorkshire and Landrace pigs) as a covariate. The significant genes after false discovery rate (<0.01) correction were AFG1L, SCAI, RIMS1, and SPDEF. The major GO terms for the top 5% of genes were related to neuronal genes, cell morphogenesis and actin cytoskeleton organization. The neuronal genes were previously reported as being associated with backfat thickness. However, the genes in our results were novel, and they included ZNF280D, BAIAP2, LRTM2, GABRA5, PCDH15, HERC1, DTNBP1, SLIT2, TRAPPC9, NGFR, APBB2, RBPJ, and ABL2. These novel genes might have roles in important cellular and physiological functions related to BF accumulation. The genes related to cell morphogenesis were NOX4, MKLN1, ZNF280D, BAIAP2, DNAAF1, LRTM2, PCDH15, NGFR, RBPJ, MYH9, APBB2, DTNBP1, TRIM62, and SLIT2. The genes that belonged to actin cytoskeleton organization were MKLN1, BAIAP2, PCDH15, BCAS3, MYH9, DTNBP1, ABL2, ADD2, and SLIT2.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.2
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• pp.105-109
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• 2008

In our country, limiting nutrient is known as phosphorus in the most lakes. Therefore, the removal of phosphorus is a very important process in sewage treatment. However, many of the sewage treatment plants employ the conventional activated sludge process, known to remove $10{\sim}30%$ of phosphorus. Thus, additional phosphorous removal process will be needed. Oyster shells have been known to remove phosphorus in water. The removal efficiency of phosphorus was highest at smallest size of oyster shells and at the highest pH for batch test. The phosphorous removal rate with various calcium concentrations was increased by increasing calcium concentration. At the 20 mg/l of calcium, more than 90% of phosphorous was removed in two hours. The removal efficiency of phosphorous was increased greatly at 300% of recirculation rate. With 300% of recirculation rate, the removal efficiency reached 80% at pH 11. The negative effects of bicarbonate on crystallization were observed in oyster shells. The effects of bicarbonate on rate constant were also investigated by applying these results to experimental equation. The rate constant was decreased at the inverse logarithm bicarbonate concentration.

• Journal of Power System Engineering
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• v.18 no.2
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• pp.5-11
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• 2014

The purpose of this study is to investigate the specific characteristics of combustion and exhaust emissions on a 4-cylinder common rail diesel engine as EGR rate and the rate of blended bio-diesel was altered. Bio-diesel fuel which is a sort of alternative fuels can be adapted to diesel engine directly without modifying. This study was performed to 2000rpm of engine speed with torque 30Nm while EGR rate and the rate of blended bio-diesel was changed. Decreasing combustion pressure and increasing the rate of heat were occurred when we had changed the EGR rate on the 20% of bio-diesel blended diesel fuel. The maximum pressure of combustion and the IMEP became higher as the EGR rate and the rate of blended bio-diesel were changed. Exhaust gas temperature was increased the higher rate of the blended bio-diesel under the fixed EGR rate. However, it went down as the EGR rate increased. The amounts of CO and Soot were reduced with increasing the rate of the blended bio-diesel without changing EGR rate and raised with increasing of the EGR rate. On the fixed EGR rate, NOx was increased along with growing the rate of the bio-diesel. On the other hand, it was decreased while EGR rate were going up.