• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.59-62
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• 2003

동위원소희석법에 의한 열이온화 질량분석법 (ID-TIMS)을 이용하여 지하수내 희토류원소의 함량을 측정하였다. 희토류원소의 분리에는 철공침법과 양이온교환수지에 의한 컬름분리법을 이용하였다. 경희토류(La-Eu)와 Gd, Dy, Er의 경우 수-수십 ppt의 수준에서 1%이내의 오차범위를 측정되어졌으며, 중희토류 중 Yb와 Lu은 정확도가 다소 떨어진 10% 전후에서 측정되었다. 지하수내 함량을 운석으로 규격화한 결과, 경희토류가 부화되었고 중희토류는 결핍되었으며 Eu의 이상은 거의 존재하지 않는다. 특히 경희토류에서는 M-type의 테트라드효과, 중희토류에서는 W-type의 테트라드효과가 관찰되었다. 이는 희토류원소의 수화수와 밀접한 관련이 있는 것으로 사료된다.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.5
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• pp.72-83
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• 2010

Experiments were conducted to investigate the effects of added diluents (carbon dioxide, nitrogen, and helium) on cellular instabilities in outwardly propagating spherical syngas-air premixed flames. Laminar burning velocities and Markstein lengths were measured by analyzing high-speed schlieren images at various diluent concentrations and equivalence ratios. Experimental results showed substantial reduction of the laminar burning velocities and of the Markstein lengths with the diluent additions in the fuel blends. Effective Lewis numbers of helium-diluted syngas-air flames increased but those of carbon dioxide- and nitrogen-diluted syngas-air flames decreased in increase of diluents in the reactant mixtures. With helium diluent, the propensity for cells formation was significantly diminished, whereas the cellular instabilities for carbon dioxide- and nitrogen-diluted syngas-air flames were not suppressed.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.11a
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• pp.378-381
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• 2011

대표적 가스계 소화약제인 $CO_2$의 소화기구(Extinguishing mechanism)를 재조명하기 위하여, $CH_4$/air 저 신장율 대향류 확산화염을 대상으로 $CO_2$가 소화에 미치는 영향에 대한 수치해석이 수행되었다. 부력이 지배적인 화염의 소화현상은 복사 열손실에 의해 큰 영향을 받기 때문에, 소화농도 예측에 대한 복사모델의 성능평가가 우선적으로 이루어졌다. 주요 결과로서, 공기류에 첨가된 $CO_2$의 소화농도는 복사모델이 고려되지 않은 경우 과다 예측되는 반면에, 간략화된 광학적으로 얇은 근사(Optically thin approximation) 모델과 비교적 높은 정확도를 갖는 좁은 밴드(Statistical narrow band) 모델은 실험의 오차범위 내에서 큰 차이를 보이지 않았다. $CO_2$가 소화에 미치는 순수 희석효과, 희석에 의한 복사효과, 화학적 효과 및 열적효과를 정량적으로 분석하기 위하여 가상의 소화약제의 개념을 도입하였다. 이를 통해 화염의 총괄신장율에 따른 $CO_2$ 소화효과에 대한 구체적인 이해가 시도되었다.

• Journal of the Korean Institute of Gas
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• v.12 no.2
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• pp.77-84
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• 2008

Experimental study was conducted to clarify the importance of buoyancy effects in laminar lifted flames which have been well understood by cold jet similarity theory. To evaluate buoyancy effects, lifted flame behaviors were systematically observed in methane and propane lifted flames diluted with He as changing the fuel nozzle diameter from 0.1 to 6 mm. Important physical parameters such as fuel strength, flame stretch and flame curvature, which were derived through simple physical scaling laws, were estimated. It is experimentally proven that buoyancy effects are important in relatively large fuel nozzle diameter and large fuel dilution with He. The results of Chen et al., which displayed the existence of stably lifted flames for 0.5

• Journal of Food Hygiene and Safety
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• v.18 no.4
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• pp.183-188
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• 2003

Bactericidal effect of $Green-Zone^{(TM)}$ was observed, when Staphylococcus aureus, E. coli O157:H7, Salmonella typhimurium, S. enteritidis, Listeria monocytogenes, the causative bacteria of food poisoning, Vibrio parahaemolyticus, and Shigella sonnei were treated with the diluted solution of $Green-Zone^{(TM)}$(33.3%~4.1%) for 30min at $20^{\circ}C$. All the bacteria were killed in 30 sec, when 33.3%-diluted $Green-Zone^{(TM)}$ was applied, except for S. aureus. Coronavirus, the same virus with SARS virus taxonomically, was also lilled with the 20%-diluted $Green-Zone^{(TM)}$. Canine parvovirus and Canine distermper virus were also killed even in the organic matter and hard water when treated with $Green-Zone^{(TM)}$. When applied to food such as raw fish, chilled meat, vegetables, $Green-Zone^{(TM)}$ could also decrease the number of microorganism, expecially for E. Coli. From these results, $Green-Zone^{(TM)}$ is thought to be effective for killing virus and bacteria, and also was proved to be safe when applied directrly to food.

• Journal of Aquaculture
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• v.12 no.1
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• pp.1-5
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• 1999

To obtain fundamental data for sperm cryopreservation in river puffer (Takifugu obscurus), the proper conditions of cryopreservation were investigated. In the sperm cryopreservation of river puffer, marine fish Rinser's solution (MFRS) was found to be good diluent and dimethyl sulfoxide (DMSO) was proved to be superior to glycerol as a cryoprotectant. The highest fertilization rate was achieved when river puffer sperms were cryopreserved with MFRS adding 5％ DMSO.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.1
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• pp.26-33
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• 1990

The behavior and mixing process of the forced plume are studied in the hydraulic laboratory. The dilution rate of discharged waste water from the port in various hydraulic condition was analized. The effect of densimetric Froude number and the discharge type on the dilution rate are discussed: In the vertical discharge, the forced plume of small densimetric Froude number mixes more actively than that of the large one. In the horizontal discharge, forced plume of large densimetric Froude number dilutes more rapidly than that of the small one. The mixing takes place more vigorously in the horizontal discharge than in the vertical one. The multi-port diffuser is more effective for the waste water discharge system than the single port diffuser in the tidal swinging coastal sea.

• Asian Journal of Turfgrass Science
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• v.15 no.4
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• pp.157-168
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• 2001

This study was carried out to investigate the offsets of pyroligneous acid on the growth of ‘Penncross’Creeping Bentgrass (Agrostis palustris Huds.) and to propose the practical use for ecologically responsive management in Korean golf courses. In the plots affected by 300, 500, and 800 times diluted pyroligneous acid, the turfgrass growth increment and the visual quality were measured at fixed periods. The data were subjected to paired samples T-test. The results summarized are as follows； 1) In leaf growth increment, density, and root spread depth, turfgrass affected by 500 and 800 times diluted pyroligneous acid were superior to the control continually. It was reliable in the statistics. Especially, 500 times diluted solutions was superior to the others. 2) In color, texture, uniformity, and recuperative strength, the visual quality of turfgrass affected by 500 and 800 times diluted pyroligneous acid were superior to the control continually. It was reliable in the statistics except the recuperative strength. Espe-cially, 500 times diluted solutions tended to be superior to the others. 3) There was no symptom of a disease in all plots. The existing management was thought to be suitable in this golf course. 500 and 800 times diluted pyroligneous acid were not thought to trigger or promote a disease, 4) After investigating the effect of pyroligneous acid on turfgrass growth, the soils of all plots were analyzed. In all plots, the chemical properties of the soils were not changed obviously. 5) Considering the results mentioned above, the practical use of 500 and 800 times diluted solutions might decrease the amount of nutrients and agricultural chemicals used in golf courses as well as promote turfgrass growth in golf courses.

• Korean Chemical Engineering Research
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• v.45 no.2
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• pp.203-207
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• 2007

In this paper efficient method for particle removal from silicon wafers by usage of HF and ozone was studied. It was found that at least 0.3 vol% concentration of HF was required for particle removal and removal efficiency increased with the application of megasonic in ozonated water. Additional cleaning with minute amount of ammonia (0.01 vol%) after HF/Ozone step showed over 99% in removal efficiency. It is proposed that the superior cleaning efficiency of HF-Ozone-ammonia is due to micro-etching of silicon surface and impediment of particle re-adsorption in alkali environment. Compared to SC-1 cleaning method micro roughness has also been slightly improved. Therefore it is expected that HF-ozone-ammonia cleaning method is a viable alternative to the conventional wet cleaning methods.

• Journal of fish pathology
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• v.24 no.3
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• pp.289-295
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• 2011

The in-vitro eliminative effects of against three types of herbal extract and formalin Ichthyophthirius multifiliis were examined. All parasites were killed within one hour after exposure to the 500 fold dilution of the complex herb extract whereas the 10 fold dilution of the fertilized solution of Salvia plebeia R. Br. killed all parasites within one hour after exposure. The 5,000 fold dilution of the extracts of Ginkgo biloba leaves killed all parasites within one hour after exposure. As a comparative agent, formalin killed all parasites within one hour at 100 ppm. As the results, the extracts of Ginkgo biloba leaves extracts have the most eliminative ability against the parasite. No differences were found among different parasite density in eliminative effects of the three types of herbal extracts and formalin. Also there were no changes in the fish gill tissues after exposure for two hours to the 5,000 fold dilution of the extract of Ginkgo biloba leaves.