• Economic and Environmental Geology
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• v.43 no.1
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• pp.43-52
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• 2010

The geochemical and nitrogen isotopic analyses for shallow groundwater of Ogcheon area were carried out to characterize the geochemical characteristics of the groundwater and to identify the source of nitrate. Groundwater shows a neutral pH to weakly alkalic condition with pH values ranging from 6.9 to 8.4. The average of EC, Eh and DO is $344.2\;{\mu}s/cm$, 195 mV, 4 mg/L, respectively. According to piper diagram, chemical composition of groundwater is dominantly characterized by Ca-$HCO_3$ type. On the other hand, groundwater type in the study area include Ca-Cl+$NO_3$ type that were highly influenced by agricultural activities. $NO_3$-N concentration of the collected samples(n=45) range from 12.4 to 34.2 mg/l. These data show that the $NO_3$-N concentration exceeds Korea Drinking Water Standard (10 mg/l). The $\delta^{15}N-NO_3$ values range from $2.7^{\circ}/_{\circ\circ}$ to $18.8^{\circ}/_{\circ\circ}$. The enrichments of heavy isotope in the groundwater indicate that major origin of nitrate pollution were associated with animal and human waste. Also the denitrification may have partly contributed as one of the sources of nitrogen.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.2
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• pp.273-280
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• 2010

This study aims to research into a plan for the spatial design on the major facilities in new-town region in Mongolia by using the spatial analytical technique in GIS. In case of Mongolian region, the demand for new-town development is rapidly increasing around Ulaanbaatar, where is the capital. On the other hand, the adequately relevant ground or the spatial-design technique is failing to be applied. This study extracted the region available for developing new down by using spatial analytical technique in GIS, and researched into the spatial-design plan for housing complex, filtration plant, sewage disposal plant, power plant, general park, crematory. The housing complex in the targeted region could be known to be adequate to be positioned around watercourse and road. It could be known to be adequate for filtration plant, which is the source of drinking water, to be located in the upper-stream region of a river, which is secured good quality of water, and for sewage disposal plant to be located in the lower-stream region available for minimizing occurrence of contamination. It is judged to be required for a proposed site of power plant to be located in the upper-stream region, for the park unit, which is space of the living culture, to be repaired and expanded the existing facilities, and for traffic network to be expanded through predicting demand along with new-town development. It is judged to be probably needed to be reflected even the flexible aspect for changing design through surveying the feasibility and economic efficiency on the future spatial design.

• Korean Journal of Food Science and Technology
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• v.40 no.1
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• pp.101-105
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• 2008

Enterobacter sakazakii is implicated in severe forms of neonatal infections such as meningitis and sepsis. This organism has been isolated from a wide range of foods, including cheese, vegetables, grains, herbs, and spices, but its primary environment is still unknown. Generally, dried infant milk formula has been epidemiologically identified as the source of E. sakazakii. Sunsik (a powdered mixture of roasted grains and other foodstuffs) is widely consumed in Korea as a side dish or energy supplement. Sunsik is consumed without heat treatment; thus, lacking an additional opportunity to inactivate foodborne pathogens. Therefore, its microbiological safety should be guaranteed. In this study, the prevalence of E. sakazakii was monitored in 23 different sunsik component flours, using FDA recommended methods; but E. sakazakii medium (Neogen) and Chromogenic E. sakazakii medium (Oxoid) were used as the selective media. In total, presumptive E. sakazakii strains were isolated from 8 different sunsik powders. Subsequently, an API 20E test was conducted, and 15 strains from 5 different sunsik flours (sea tangle, brown rice, non-glutinous rice, cheonggukjang, dried anchovy) were confirmed as E. sakazakii. Fifteen strains were again confirmed by PCR amplification, using three different primer sets (tDNA sequence, ITS sequence, 16S rRNA sequence), and compared to ATCC strains (12868, 29004, 29544, 51329). They were once again confirmed by their enzyme production profiles using an API ZYM kit. Finally, RAPD (random amplified polymorphic DNA)-genotyping was carried out as a monitoring tool to determine the contamination route of E. sakazakii during processing.

• Journal of Radiation Protection and Research
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• v.34 no.3
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• pp.107-114
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• 2009

A Compton camera, which is based on Compton kinematics, is a very promising gamma-ray imaging device in that it could overcome the limitations of the conventional gamma-ray imaging devices. In the present study, the image quality of a rotating Compton camera was evaluated by using 4-D Monte Carlo simulation technique and the applicability to nuclear industrial applications was examined. It was found that Compton images were significantly improved when the Compton camera rotates around a gamma-ray source. It was also found that the 3-D imaging capability of a Compton camera could enable us to accurately determine the 3-D location of radioactive contamination in a concrete wall for decommissioning purpose of nuclear facilities. The 4-D Monte Carlo simulation technique, which was applied to the Compton camera fields for the first time, could be also used to model the time-dependent geometry for various applications.

• Korean Journal of Environmental Agriculture
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• v.26 no.3
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• pp.210-216
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• 2007

The cadmium (Cd) and zinc (Zn) contamination of soils and cultivated crop plants by zinc smelting activities was studied. In the study area of the vicinity of ${\triangle}{\triangle}$ zinc smelting factory in Korea, soils and corn plants were sampled at corn harvesting stage and analyzed Cd and Zn concentration as well as Cd and Zn fraction and chemical properties in soils. At 600 m radius of studied area, Cd and Zn were highly accumulated in the surface soils (0 - 20 cm) showed greater than the Korean warning criteria (Cd 1.5, Zn 300 mg $kg^{-1}$) with corresponding values 1.7 and 407 mg $kg^{-1}$, respectively. The leaf part gave higher Cd concentration with the corresponding value of 9.5 mg $kg^{-1}$ as compared to the stem and grains pare (1.6 and 0.18 mg $kg^{-1}$), respectively. Higher Zn concentration was also obtained from the leaf part of the corn plant which gave the value of 1,733 mg $kg^{-1}$. The stem and grain part gave corresponding values of 547 and 61 mg $kg^{-1}$. The order of the mean Cd concentration in fractions is F3 (oxidizable fraction) > F2 (reducible fraction) > F4 (residual fraction) > F1 (exchangeable + acidic fraction). A highly positive correlation is observed between F2 and concentration of Cd and Zn in both plant pare, leaf and grain. Highly positive correlations are shown in the pH exchangeable Ca and Mg, and CEC when correlated with Cd and Zn bound to F4 fractions. To reduce Cd and Zn uptake by corn plant in an arable land heavily contaminated with Cd and Zn as affected by smelting factory, an efficient and effective soil management to increase soil pH and CEC is thus recommended.

• 한국균학회소식:학술대회논문집
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• 2018.05a
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• pp.44-44
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• 2018

Fusarium head blight (FHB) caused by infection with Fusarium graminearum leads to enormous losses to crop growers, and may contaminate grains with a number of Fusarium mycotoxins that pose serious risks to human and animal health. Antagonistic bacteria that are used to prevent FHB offer attractive alternatives or supplements to synthetic fungicides for controlling FHB without the negative effects of chemical management. Out of 500 bacterial strains isolated from soil, Bacillus amyloliquefaciens JCK-12 showed strong antifungal activity and was considered a potential source for control strategies to reduce FHB. B. amyloliquefaciens JCK-12 produces several cyclic lipopeptides (CLPs) including iturin A, fengycin, and surfactin. Iturin A inhibits spore germination of F. graminearum. Fengycin or surfactin alone did not display any inhibitory activity against spore germination at concentrations less than 30 ug/ml, but a mixture of iturin A, fengycin, and surfactin showed a remarkable synergistic inhibitory effect on F. graminearum spore germination. The fermentation broth and formulation of B. amyloliquefaciens JCK-12 strain reduced the disease incidence of FHB in wheat. Furthermore, co-application of B. amyloliquefaciens JCK-12 and chemical fungicides resulted in synergistic in vitro antifungal effects and significant disease control efficacy against FHB under greenhouse and field conditions, suggesting that B. amyloliquefaciens JCK-12 has a strong chemosensitizing effect. The synergistic antifungal effect of B. amyloliquefaciens JCK-12 and chemical fungicides in combination may result from the cell wall damage and altered cell membrane permeability in the phytopathogenic fungi caused by the CLP mixtures and subsequent increased sensitivity of F. graminearum to fungicides. In addition, B. amyloliquefaciens JCK-12 showed the potential to reduce trichothecenes mycotoxin production. The results of this study indicate that B. amyloliquefaciens JCK-12 could be used as an available biocontrol agent or as a chemosensitizer to chemical fungicides for controlling FHB disease and as a strategy for preventing the contamination of harvested crops with mycotoxins.

• 한국문화재보존과학회:학술대회논문집
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• 2004.10a
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• pp.15-24
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• 2004

The Seokgatap pagoda composed of mainly alkali granite and other minor pink-feldspar granite, fine-grained granite, granodiorite, diorite, gabbro, and tuff. Despite the small loss and damage derived from joints, its peel-off and exfoliation are serious enough to cause the heavy deterioration on the stone surface. The chemical and petrological weathering has partly replaced the original rock-forming minerals with clay minerals and iron oxyhydroxides. Based on the petrogenesis, rock materials of the pagoda is very similar to rocks of Dabotap pagoda and the Namsan granite in the Gyeongju. The central fart of the pagoda has sunken highly, which caused all the corners to split and the structural transformation to become worse. The reverse V-shaped gaps between the materials have broken stones filled in a coarse way. The iron plates inserted between the upper flat stone laid on other stones and tile pagoda body in the north and east side has been exposed in the air and corroded, discoloring of the adjacent stones. The overall diagnosis of the Seokgatap pagoda is the deteriorated functions of the stone materials, which calls for a long-term monitoring and plans to reinforce the stone surfaces. But the main body including the pagoda roof stone needs washing on a regular basis, and the many different cracks should be fixed with glue by using the fillers or hardeners designed for stone cultural properties after removing the cement mortar. In case of the replacement of the stone materials with new stones, it's necessary to examine the pagoda for the center of gravity and support intensity of the materials. The structural stability of the pagoda can be attained by taking a reinforce measure in geotechnical engineering and making a drainage. The ground humidity, which has aggravated weathering and structural instability, should be resolved by setting up a humidity reduction facility. The contamination of lichens and bryophyte around the pagoda and on the surface is serious. Thus biochemical treatments should be given too in order to prevent further biological damages and remove the vegetation growing on the discontinuous planes.

• Microbiology and Biotechnology Letters
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• v.38 no.3
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• pp.335-339
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• 2010

A diesel-degrading bacterium, Gordonia sp. SD8, was isolated from soil contaminated with petroleum, and its diesel degradation was characterized in a soil as well as a liquid culture system. SD8 could grow in the mineral salt medium supplemented with diesel as a sole carbon and energy source. The maximum specific growth rate ($0.67{\pm}0.05\;d^{-1}$) and diesel degradation rate ($1,727{\pm}145$ mg-TPH $L^{-1}\;d^{-1}$) of SD8 showed at 20,000 mg-TPH $L^{-1}$ and $30^{\circ}C$, and then this bacterium could degrade high strength of diesel of 40,000 mg-TPH $L^{-1}$. The residual diesel concentration in the inoculated soil with SD8 was 3,724 mg-TPH kg-dry $soil^{-1}$ after 17 days, whereas the diesel concentration in the non-inoculated soil was $8,150{\pm}755$ mg-TPH kg-dry $soil^{-1}$. These results indicate that Gordonia sp. SD8 can serve as a promising microbial resource for the bioremediaion of contaminated soil with petroleum hydrocarbons including diesel.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.1
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• pp.1-8
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• 2017

Drinking water deficiency is prevalent in developing countries due to contamination of surface and ground water, difficulties of water treatment, and lack of water infrastructures. 'Rainwater For Drinking (RFD)' projects are emerging as one of the effective solutions globally since RFD systems provide safe drinking water from rainwater. In RFD projects, perception of local residents toward RFD project is essential as local residents must manage their RFD systems on their own after the project finishes. This research performed survey and interview to 209 local residents, who use RFD systems, and analyzed their general perception, expected effects and feared factors toward RFD projects. Through the research, it was shown that the most of the local residents have positive perception towards RFD projects' effectiveness (41.9%) and are willing to participate (58.9%). The top three expected effect factors of the RFD projects were 'supply of safe water source', 'vitalization of local community', and 'expansion of RFD system'. The top three feared factors were 'quality of rainwater', 'technical factors of RFD system', and 'maintenance of RFD system'. The research findings indicate that development of simple water quality measuring device and education of the local residents about RFD system is necessary for better maintenance of the RFD system after the project finishes.

• Journal of agricultural medicine and community health
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• v.40 no.2
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• pp.53-61
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• 2015

Objectives: An outbreak of food poisoning occurred among the baseball club students at a high school in Ulsan city in 2014. An epidemiological investigation was carried out to examine the infection source and the transmission route of pathogen, and to prevent a recurrence. Methods: A questionnaire survey was conducted for 26 male students and 2 food handlers. Rectal swabs were examined in 7 students and the 2 food handlers, and an environmental investigation was performed. A retrospective cohort study was used to evaluate the association between risk factors and disease. Results: The attack rate was 35.7% (10 persons/28 persons) from June 9 to 14, and Enterotoxigenic E. coli ST/LT was isolated from 7 among 28 persons. The study revealed that no food was a significant risk factor for the outbreak. There were no connection between environmental factors and the outbreak. Conclusions: The major risk factors for this outbreak were presumed to be the contaminated ice cube and ice making machines and eating ice cube from the machines. More strict personal and environmental hygiene need to be enforced to prevent such outbreaks.