• Journal of Korean Society for Atmospheric Environment
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• v.19 no.E4
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• pp.177-186
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• 2003

The total of 1,454 aerosol samples were collected by high volume tape sampler at the Gosan Site in Jeju Island from 1992 to 1999, and the major water-soluble ionic components were chemically analyzed. The mean concentrations of nss-S $O_4$$^{2-}$, N $H_4$$^{＋}$, and N $O_3$$^{[-10]}$ showed high values, which were 6.73, 1.45, and 1.45 ${\mu}{\textrm}{m}$/㎥, respectively, while $Ca^{2+}$ and $K^{+}$ concentrations were low with the values of 0.49 and 0.42 $\mu\textrm{g}$/㎥. The concentrations of most components increased in spring but decreased in summer, especially with the remarkable increase of $Ca^{2+}$ and N $O_3$$^{[-10]}$ concentrations in spring. The seasonal comparison of nss-S $O_4$$^{2-}$ concentrations showed higher values with the order of spring > fall 〉 winter〉 summer, but spring 〉 winter〉 fall 〉 summer for N $O_3$$^{[-10]}$ Meanwhile, the concentration levels of N $a^{+}$ and C $l^{[-10]}$ increased more in winter season. According to the investigation of wind direction effect, the concentrations of most aerosol ionic components showed higher values consistently at the westerly and northerly wind conditions. Based on the factor analysis, the atmospheric aerosols in the Gosan Site are considered to be largely affected by marine sources, followed by anthropogenic and soil sources.urces..

• The Journal of Engineering Geology
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• v.24 no.4
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• pp.583-595
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• 2014

The chemical properties and composition (pH, CaO, Fe, $HCO{_3}^-$, and $SO{_4}^{2-}$) of groundwater (GW) and surface water (SW) from the northern (non-carbonate bedrock) and southern (carbonate bedrock) sections of the Daedong River, Pyeongyang were analyzed and compared period of the 1930s. In the southern section, the GW and SW has a higher pH and $SO{_4}^{2-}$ concentration, but lower $HCO{_3}^-$ and Fe levels than in the north. This finding reflects a reaction that formed acid by replacing metal ions in inorganic salts by hydrogen, which resulted from the oxidation of organic material in a clay layer.

• Journal of Animal Environmental Science
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• v.1 no.1
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• pp.65-75
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• 1995

This experiment was carried out to the effects of population density and C/N ratios of feed on the growth, reproductive effciency and cast producation of the earthworm(Eisenia foetida). The population densities of 50, 100, 150, 200 and 250 individuals of the earthworm fed with different C/N ratios of 25, 35, 45 and 55 cow manures were studied in rearing box($6,400cm^3$), and at the fertility stage during a period of 60 days. The results were summarized as follows; The survial rate(SR), increasing rate(IR), reproductive efficiency(RE) and cast production of the earthworms showed highest values in C/N ratio of 25. These results may indicate that C/N ratio of 25 is a very favourable feed for the growth of the earthworms. The survial rate(SR) indicated significant positive correlation with reproductive efficiency(RE) in different C/N ratios of feeds. The survial rate(SR) showed highest values in population densities of $50{\sim}100$ worms/$6,400cm^3(64.0{\sim}128.0cm^3/worm$). On the contrary, increasing rate(IR) tended to decreased with the increased population densities. The survival rate(SR) indicated significant negative correlation with reproductive efficiency(RE) in different population densities of the earthworms. The cast production estimated were $31.6mg{\sim}67.4mg/day/worm$ grown in optimum population densities($50{\sim}100\;worms/6,400cm^3$). The earthworm casting are an excellent soil conditioning material or organic fertilizer sources with a high chemical composition and their physical properties.

• The Plant Pathology Journal
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• v.29 no.2
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• pp.144-153
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• 2013

Diverse bacteria are known to colonize plants. However, only a small fraction of that diversity has been evaluated for their biopesticide potential. To date, the criteria for sampling and selection in such bioprospecting endeavors have not been systematically evaluated in terms of the relative amount of diversity they provide for analysis. The present study aimed to enhance the success of bioprospecting efforts by increasing the diversity while removing the genotypic redundancy often present in large collections of bacteria. We developed a multivariate sampling and marker-based selection strategy that significantly increase the diversity of bacteria recovered from plants. In doing so, we quantified the effects of varying sampling intensity, media composition, incubation conditions, plant species, and soil source on the diversity of recovered isolates. Subsequent sequencing and high-throughput phenotypic analyses of a small fraction of the collected isolates revealed that this approach led to the recovery of over a dozen rare and, to date, poorly characterized genera of plant-associated bacteria with significant biopesticide activities. Overall, the sampling and selection approach described led to an approximately 5-fold improvement in efficiency and the recovery of several novel strains of bacteria with significant biopesticide potential.

• Journal of Plant Biotechnology
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• v.7 no.3
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• pp.203-209
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• 2005

This study was conducted to improve tocopherol (vitamin E) composition in soybean (Glycine max) by introducing a gamma-tocopherol methyl transferase (${\gamma}$-TMT) gene via Agrobacterium tumefaciens-mediated transformation. Immature cotyledon explants were cocultivated with Agrobacterium tumefaciens. Putative transgenic embryos were selected from immature cotyledons on MS medium supplemented with 40 mg/L 2,4-D containing 100 mg/L kanamycin, 500 mg/L carbenicillin and 250 mg/L cefotaxime. Plantlets were developed from somatic embryos, and then transferred to soil. Nineteen regenerated plantlets obtained on the selection medium from 1,460 cotyledons. However, only 9 plantlets were confirmed as transformed plants. Integration of the transgene into the soybean genomic DNA was confirmed by PCR and Southern blot analysis. HPLC analysis showed that the content of ${\alpha}$-tocopherol in transgenic soybean seeds (AT-1) was approximately 4-fold higher than that of non-transgenic plants. Conclusively, we obtained the transgenic soybean having increased ${\alpha}$-tocopherol content by the overexpression of ${\gamma}$-TMT transgene.

• Korean Journal of Microbiology
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• v.31 no.4
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• pp.261-266
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• 1993

A new methyltrophic bacterium which utilizes methanol as a sole source of carbon and energy was isolated from soil. It was Gram-negative, nonmotile, nonspore-forming rod, and strictly aerobic bacterium. Catalase and oxidase activities were present. Nitrate was reduced to nitrite. Vitamins and other growth factors were not required. Generation time was 1.6 hr under the optimal condition. The isolate assimilated methanol via the ribulose mono-phosphate pathway (Enter-Doudoroff varient) and did not have .alpha.-ketoglutarate dehydrogenase. It assimilated ammonia through glutamate dehydrogenase. The guanine plus cytosine content of the DNA was 61.0 mol%. The celular fatty acid composition was primarily straight-chain saturated $C^{16 : 0}$ acids (palmitic acids) and unsaturated $C_{16 :1}$ acid (palmitoleic acids), and the isolate also contained two unidentified $C_{17}$ branched fatty acids. The major ubiquinone was Q-8, and Q-6 and Q-7 were present as minor components. Phosphatidylethanolamine and phosphatidylglycerol were predominantly present, and diphosphatidyglycerol was also detected. Based on the physiological and biochemical properties, the isolate was assigned to a novel species of the genus Methylobacillus, Methylobacillus methanolovorus sp. nov.

• Applied Biological Chemistry
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• v.40 no.6
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• pp.459-464
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• 1997

A cyclodextrin glycosyltransferase-producing bacterium was newly isolated from soil using alkaline pH medium containing 1% $Na_2CO_3$. The isolated strain was identified as Bacillus brevis by morphological and biochemical characteristics, and fatty acid composition and designated Bacillus brevis CD162. The strain showed the best enzyme production of 0.9 unit/ml after 96 hrs of culture at $30^{\circ}C$ in a medium of 2.0% soluble starch, 0.75% yeast extract, 0.5% bacto peptone, 0.2% $K_2HPO_4$ 0.05% $MgSO_4{\cdot}7H_2O$, and 1.5% $Na_2CO_3$ at initial pH 10.2.

• Economic and Environmental Geology
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• v.36 no.4
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• pp.269-274
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• 2003

This study, one of the projects for investigation of the precious metal deposits of the Circum-Pacific Ocean coon-tries, was performed in a gem field of Pailling, Cambodia, in which there are numbers of undeveloped mineral resources. The gem fields in the Pailling area are typically distributed in the laterite, lying on of weathered basalts. The gem grade of corundum is low in the surface soil horizon(less than 1 m in depth), but is higher in the subsurface. Occurrence and genetic environment of the precious stone are not concerned in the soils. A Precious stone that is already made from at the least upper part of volcanic rocks is produced in large quantities to undergoing to weathering of the rocks. A precious stone is made from upper part of the formation under the high temperature when volcano is vomiting or after vomiting. and/or made from between the formation under the high temperature when other volcano is vomiting. Volcanic rocks including precious stone are a little different from other volcanic rocks when volcano is vomiting, but chemical composition of rocks is not far different from other volcanic rocks.

• Journal of Energy Engineering
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• v.26 no.4
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• pp.45-56
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• 2017

Coal power plants produce electricity for the nation's power grid, but they also produce more hazardous air emissions than any other industrial pollution sources. The quantity is staggering, over 386,000 tons of 84 separate hazardous air pollutants spew from over 400 plants in 46 states. In South Korea also, annual coal ash generation from coal-fired power plants were about 6 million tons in 2015. Pollutants containing particulate matter 10, 2.5 (PM10, PM2.5), heavy metals and dioxins from coal-fired power plant. The emissions threaten the health of people who live near these power plants, as well as those who live hundreds of miles away. These pollutants that have long-term impacts on the environment because they accumulate in soil, water and animals. The present study is to investigate the physical and chemical characteristics of coal-fired power plant fly ash and bottom ash contains particulate matter, whose particulate sizes are lower than $PM_{10}$ and $PM_{2.5}$ and heavy metals. There are wide commercial technologies were available for monitoring the PM 2.5 and ultra-fine particles, among those carbonation technology is a good tool for stabilizing the alkaline waste materials. We collected the coal ash samples from different coal power plants and the chemical composition of coal fly ash was characterized by XRF. In the present laboratory research approach reveals that potential application of carbonation technology for particulate matter $PM_{10}$, $PM_{2.5}$ and stabilization of heavy metals. The significance of this emerging carbonation technology was improving the chemical and physical properties of fly ash and bottom ash samples can facilitate wide re use in construction applications.

• Korean Journal of Plant Resources
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• v.24 no.1
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• pp.89-97
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• 2011

Shallot is a foreign crop introduced from France in 1995 as a new overwintering field crop with an aim to develop as an export crop. This study was conducted to investigate the effect of nitrogen fertilization level and time of supplementary nitrogen fertilization on growth and development of shallot, and to suggest to several problems raised during introductory trial cultivations. Optimum amount of nitrogen fertilization for bulb yield was 24 kg per 10 a. The best time of supplementary fertilization was February and March, with an equal amount in each month. The inorganic element composition of the harvested bulbs was not significantly affected by N fertilization level or by time of supplementary nitrogen fertilization.