• Journal of Korean Society for Atmospheric Environment
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• v.34 no.3
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• pp.406-417
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• 2018

In this study, $PM_{2.5}$ samples were collected during approximately 3 years in Chuncheon, a small residential and tourist city, in Korea. The average $PM_{2.5}$ concentration was $26.9{\mu}g/m^3$, exceeding the annual national air quality standard. $PM_{2.5}$ showed typical seasonal variation, having higher concentration in winter and lower concentration in summer. Sixteen metallic elements in $PM_{2.5}$ were also analyzed, and K was the highest contributor especially in late fall and winter. In addition, K considerably increased for the top 10% of $PM_{2.5}$ samples and showed the highest correlation coefficient with $PM_{2.5}$ among all other metallic elements. These results suggest that the combustion of agricultural residue and other biomass, the major source of K was likely to be important to high $PM_{2.5}$ concentration events in this city. Crustal elements including Al, Fe, Si, Ti, Mg showed high concentration in spring while Cr, Cu and Ni were relatively consistent throughout a year. Principal component analysis was used to trace the sources, and soil re-suspension, combustion of biomass and fossil fuels, and asphalt concrete production were identified as the main sources of $PM_{2.5}$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.4
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• pp.493-498
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• 1986

In order to evaluate the effect of various cultural methods developed during last 30 years on grain yield of wheat and barley and structure of plant stand for uptake of nutrient and water, solar energy use and com-petitive capacity with weed, 10 kinds of cultural practices were compared in the clayey upland soil. Row fertilization is more effective for uptake of N,P and K than rotary fertilization. Weed occurrence was deeply related with width of non-seeded area in the row and affected yield decrease. Winter injury was more serious in the cultural practices with thick plant community than in those with isolated individual plant. Root distribution was more remarkable in drill seeding or broadcasting than row seeding and had positively correlated with water consumption of barley.

• Economic and Environmental Geology
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• v.30 no.5
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• pp.443-450
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• 1997

The main purpose of this study is to investigate mineralogical and chemical changes during natural weathering, and assess the mobility of major and trace elements. Yongwol power plant utilize anthracite coal which is mainly composed of illite, kaolinite, pyrophyllite and quartz in mineralogy. Coal and coal-derived fly ash samples were sampled by the electrostatic precipitator in Yongwol coal-fired power plant in Korea. Short term weathered fly ash were also collected in ash disposal mound, and two profile soil samples were taken from an ash near the power plant. Amorphous materials are the main component of the fly ash, and mullite, quartz, magnetite and heamatite are present in all coal-derived fly ash. In chemistry, Si and Al are the most abundant elements of the total content. The ash samples were fractionated into upper $90{\mu}m$ and under $45{\mu}m$ size. Finer particles show higher concentrations in metal contents including Co, Cr, Cu, Ni, V, Zn and Pb. Concentration of Zn and Pb are nearly 4 times higher concentration in the finer particles. For the profile samples, the concentrations of $SiO_2$, $Na_2O$, MgO and $K_2O$ generally show increasing trends with depth, whereas those of $Fe_2O_3$ and $TiO_2$ appear to decrease with depth. Content of MnO does not show any specific depth trend. For the trace elements, Co, Cu, Ni and V show increasing concentrations with depth.

• Asian Journal of Atmospheric Environment
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• v.5 no.2
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• pp.65-78
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• 2011

Ozone ($O_3$) is a main component of photochemical oxidants, and a phytotoxic anthropogenic air pollutant. In North America and Europe, the current concentration of $O_3$ has been shown to have significant adverse effects on vegetation. In this review, we summarize the experimental studies on the effects of $O_3$ on the growth and photosynthetic activity of Japanese forest tree species to understand the present knowledge and provide sound basis for future research toward the assessment of $O_3$ impacts on Japanese forest ecosystem. Since the 1990s, several Japanese researchers have conducted the experimental studies on the effects of ambient levels of $O_3$ on growth and physiological functions such as net photosynthesis of Japanese forest tree species. Although the sensitivity to $O_3$ of whole-plant growth is quite different among the species, it was suggested that the current ambient levels of $O_3$ in Japan are high enough to adversely affect growth and photosynthetic activity of Japanese forest tree species classified into high $O_3$ sensitivity group such as Japanese beech. The N load to soil has been shown to reduce the sensitivity to $O_3$ of Japanese larch and increase that of Japanese beech. To establish the critical level of $O_3$ for protecting Japanese forest tree species, therefore, it is necessary to take into account the N deposition from the atmosphere. There is little information on the combined effects of $O_3$ and other environmental factors such as elevated $CO_2$ and drought on growth and physiological functions of Japanese forest tree species. Therefore, it is necessary to promote the experimental study and accumulate the information on the combined effects of $O_3$ and any other abiotic environmental factors on Japanese forest tree species.

• Journal of the Korean Professional Engineers Association
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• v.19 no.1
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• pp.12-24
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• 1986

The number of visiters to Bukhan Mt. national park, generation quantity of solid waste and collection system were researched to consider a counterplan for the pollution control of the national park and study for developing the effective treatment of solid waste was tried through the proximate analysis of each component containing. Results obtained in this study were summerized as follows; The great part of visitors go on an excursion to the Bukhan Mt. national park during July and August and also, the solid waste was generated nearly a half of the total amount at the same period. The major collection facilities in the national park were waste basket and incineration box. But the incineration box was too large in volume and very far in distance, and its collection period was irregular, so it was cause to the congestion of solid waste and bad smell and dirty. Therefore, to complete collection of solid waste, we must set up the waste basket which able to find within 40～50m from the origination place of solid waste and induce the visitors to throw the solid waste. It was obtained as moisture content: 48.5 wt%, volatile solid: 28.4wt％, fixed solid: 23.1 wt％, lower heating value: 1,320kca1/kg from experimental analysis of solid waste. According to this analysis, the incineration operation is possible, but the generation quantity of solid waste was too small to construct incineration plant for heat recovery. It was found that it is suitable for the aerobic composting by mixing with the night soil which generate in the national park after the recovery of resources such as metals, glasses and plastics.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.2
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• pp.198-203
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• 1993

The cyst of Scrippsiella trochoidea from the surface mud in Masan Bay was germinated in the incubator for the culture. This species was one of dinoflagellates responsible for the early spring bloom in the southern coastal water of Korea. The culture experiments were carried out under the various gradients of environmental factors to know their effects on the population growth of this dinoflagellate. With respect to the effects of environmental factors on the growth, it was proved that the maximum cell growth was occurred at 4,000 lux of light intensity, salinity $30\%0$ and temperature $20^{\circ}C$. When 0.25ml/ml of the filtrates of Skeletonema costatum culture medium and the supernatants of soil extracts were added to growth medium as organic growth stimulants, both materials enhanced the population growth. In the fatty acid composition of S. trochoidea, $C_{16:0}$ was the major component, and $C_{18:0},\;C_{18:1},\;C_{22:0}\;and\;C_{22:1}$ were a minor components.

• Journal of Microbiology and Biotechnology
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• v.12 no.1
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• pp.71-76
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• 2002

Soil samples were screened for actinomycete strains capable of producing phospholipase D, and a strain, Streptomyces sp. YU100, showing a high transphosphatidylation activity was isolated. This strain secreted phospholipase D in a culture broth after 12 h of cultivation, and its productivity continued to increase for 36 h of fermentation. In addition, its transphosphatidylation rate of phosphatidylcholine to phosphatidylserine was almost $68\%$ within 1 h. The morphological and chemotaxonomical characteristics showed that this strain could be classified as a number of the Streptomycetaceae family, particularly due to the spiral form of its spore chain consisting of 60-70 smooth spores $(0.75{\times}1.0{\mu}m$) on an aerial mycelium, FA-2c type of fatty acid profile in the cell wall, and LL-DAP component in the cell wall peptidoglycan. A phylogenetic analysis of the 16S rDNA provided a clue that the strain YU100 was actually a member of the genus Streptomyces, because the determined sequence exhibited a higher homology with Streptomyes sp. ASB27, S. peucetius JCM9920, and S. griseus ATCC10137. A dendrogram based on the 16S rDNA sequences also showed a phylogenetic relationship between the strain YU100 and these strains. However, the strain YU100 has not yet been assigned to a particular species, because of absence of any other classified species with a high matching score.

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.2
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• pp.53-58
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• 1999

This study was carried out evaluate to identify water quality and contamination characteristics of the shallow groundwater. and their seasonal variation in the rual area of the Yongin city. Groundwater sample were collected two times (in April and September) from a total of 19 well for domestic water supply. and surface-water samples from six locations. For cations, Ca and Mg predominated. In anion competition. the influence of Cl was obvious in the april samples. However. HCO$_3$ was a major component in the september samples. Electric conductivities and the concentrations of NO$_3$-N in groundwater samples significantly decreased from the april samples to the september samples This indicates a significant seasonal variation in the shallow groundwater composition. When the shallow aquifer is connected to the surface water. then metals sorbed on the stream sediments could occur at nearby wells through the induced recharge. Contaminants at ground surface appeared to be transported to the groundwater system infiltration during the spring melt.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.1
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• pp.61-67
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• 2002

Sawdust, peat, and sawdust+peat were used as bulking agent in the compost production process using three different origin of manure; cow, pig, and chicken. The organic content and individual N, P, K content of the final manure compost were higher when peat or peat+sawdust were used to control the moisture. The carbon to nitrogen ratio and moisture content were low when peat or peat+sawdust were employed. In the case of cow and pig manure compost produced with peat or peat+sawdust, beneficial microorganism content was also higher than that of the manure samples produced with sawdust only. These results indicate that peat can be a useful component in the production of high quality manure compost.

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.2
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• pp.87-94
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• 1999

This study is providing Modified DRASTIC Model to which lineament density and land use are added as additional factors using geographic infomation system(GIS). and then to evaluate groundwater contamination potential of Pyungtek-Gun area in Kyunggi-Do. In this study. the reason for using additional factors is because. in case of lineament density. when we consider that most of aquifer is bedrock aquifer in hydrogeologic environment of the Korea, lineament is very important to flow of groundwater and contamination material. and because land use can reflect indirectly impact of point or non_point source in study area. For statistical analysis. vector coverage per each factor is converted to grid layer and after each correlation coefficient between factors, covariance, variance. eigenvalue and eigenvector by principal component analysis of 3 direction. are calculated. correlation between factors is analyzed. Also after correlation coefficients between general DRASTIC layer and rated lineament density layer and between general DRASTIC layer and rated land use layer are calculated. final modified DRASTIC Model is constructed by using them with each weighting. when modified DRASTIC Model was compared with general DRASTIC Model, comtamination potential in modified DRASTIC Model is fairly detailed and consequently. vulnerable area which has high contamination potential could be presented concretly.