• Proceedings of the KSME Conference
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• 2001.11b
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• pp.167-171
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• 2001

Air-staging combustion is a relatively well-known technique to reduce NOx emission and used in combination with other techniques nowadays. However, the design variables are still selected depending upon operating circumstances. Though the fuel-rich condition of the primary combustion zone is very helpful to NOx reduction, its range is known to be restricted by the increase of carbon monoxide. However, in many cases carbon monoxide level is so low not to be the restriction at all. So we tried to expand the equivalence ratio range to the richer condition in the primary combustion zone and make the function of each burner component and its contribution to the overall NOx production clear.

• Journal of the Korean Society of Safety
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• v.13 no.1
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• pp.70-76
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• 1998

The smoke filling process for the atrium space containing a fire source is simulated using two types of deterministic fire models : Zone model and Field model. The zone model used is the CFAST(version 1.6) model developed at the Building and Fire Research Laboratories, NIST in the USA. The field model is a self-developed fire field model based on Computational Fluid Dynamics(CFD) theories. This article is focused on finding out the smoke movement and temperature distribution in atrium space which is cubic in shape. A computational procedure for predicting velocity and temperature distribution in fire-induced flow is based on the solution, in finite volume method and non-staggered grid system, of 3-dimensional equations for the conservation of mass, momentum, energy, species and so forth. The fire model i. e. Zone model and Field model predicted similar results for the clear height and the smoke layer temperature.

• Economic and Environmental Geology
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• v.20 no.4
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• pp.247-260
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• 1987

As a part of study on the structure of the Yangsan Fault, geological and VLF EM studies have been made in the fault area approximately between Kyeongju and Eonyang. The result provides comparatively clear information on the trace of the fault and extent of fracture zone as well as the structural characteristics of the Yangsan Fault area. The location of fault trace identified from this VLF EM study coincides well in general with that expected from geological information of the area. And the extent of fault fracture zone turn out to be characterized by U shaped low resistivity zone whose width increases from north to south.

• KSBB Journal
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• v.17 no.3
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• pp.266-270
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• 2002

Alcohol fermentation conditions for the production of Chinese quince wine were investigated. Ethanol was produced maximally when 5% Saccharomyces cerevisiae was added to Chinese quince iuices and fermented at $25^{\circ}C$ for 10 days. Physiological functionalities of the Chinese quince wines were determined and compared with those of Chinese quince liquors made by seating of Chinese quince in a mixture of commercial soju and 10% sugar for 30 days and 60 days. Angiotensin-converting enzyme inhibitory activity and fibrinolytic activity of the Chinese quince wine were 36.7% and 24.0 U, respectively. Tyrosinase inhibitory activity and nitrite scavenging activity of the Chinese quince liquors were 96.7% and 52.7%, respectively and it were similar to those of the Chinese quince liquor trade from soaking of 60 days. Chinese quince wine was showed strong antibacterial activities against Staphylococcus aureus (8.5 mm of clear zone) and Klebsiella pneumonia(4.0 mm of clear zone).

• The Korean Journal of Community Living Science
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• v.24 no.1
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• pp.27-36
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• 2013

This study was performed to investigate the antimicrobial effect against food-borne pathogens of Sanguisorbae officinalis L. ethanol extract. The antimicrobial activity of the ethanol extract was determined using a paper disc-diffusion method and the diameter of the clear zone was measured. The diameters of the clear zone in the presence of 10 mg of the ethanol extract were the maximum against Staphylococcus aureus among the tested 4 gram-positive bacteria and Pseudomonas aeruginosa among the tested 7 gram-negative bacteria. Analysis of the minimum inhibition concentrations (MIC) showed that the ethanol extract exhibited a similar efficacy as sorbic acid, well-known chemical preservatives. The growth inhibitory effects of the ethanol extract in the concentrations of 250, 500, 1,000 and 2,000 mg/L on food-borne pathogens were determined against Staphylococcus aureus, Bacillus subtilis, Salmonella Typhimurium and Pseudomonas aeruginosa. The growth of the microorganisms was significantly (p<0.05) inhibited by the ethanol extract in the concentrations higher than 250 mg/L. Thus, the results of the present study demonstrate that the ethanol extract exhibits antimicrobial effects against food-borne pathogens, suggesting that Sanguisorbae officinalis L. could be used as natural antibacterial agent in food.

• International Journal of Oral Biology
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• v.40 no.4
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• pp.167-173
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• 2015

The purpose of this study was to investigate the antibacterial effect of the low temperature atmospheric plasma device with needle tip designed for easy approach to the oral cavity and root canal against Streptococcus mutans, Enterococcus faecalis and Candida albicans. The antibacterial activities evaluated by measuring clear zone of agar plate smeared with each bacteria after plasma treatment. To quantify antibacterial effects, dilution plate method was used. In addition, scanning electron microscope (SEM) was used for observation of changes in bacterial morphology. As treatment time of plasma increased, the clear zone was enlarged. The death rate was more than 99%. The SEM results showed that the globular shape of bacteria was distorted. These results suggest that needle tip plasma could be an innovative device for prevention of dental caries, and treatment of apical infection and soft tissue diseases.

• Mycobiology
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• v.34 no.2
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• pp.108-110
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• 2006

To understand the ability of producing cellulolytic enzyme activity in the sapstaining fungi, four species of Ophiostoma and two species of Leptographium were investigated in the culture media containing each of cellulose substrates such as CM-cellulose, Avicel and D-cellobiose and each of chromogenic dyes such as Congo-Red, Phenol Red, Remazol Brilliant Blue and Tryphan Blue. When the fungi were grown for $5{\sim}7$ days at $25^{\circ}C$, the formation of clear zone by chromogenic reaction around the margin of the fungal colony was demonstrated in all the culture media Congo-Red containing CM-cellulose. There was difference in the formation of clear zone among the dyes. Only Ophiostoma setosum and Leptographium spp. showed cellulolytic activity to the three substrates. Overall, the results of this study show that ophiostomatoid sapstaining fungi can produce cellulolytic enzymes.

• Food Science and Preservation
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• v.9 no.1
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• pp.97-101
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• 2002

Antimicrobial and antioxidative activities of various solvent extracts from different parts of the loquat were investigated to process it as the functional food. The extraction yield showed higher in butanol fraction of 4.95% in peel and 4.42% in seed than others, but water fraction showed high extraction yield of 3.89% in leafs 23.6% in the seedless fruit and 21.1% in fresh, In the antimicrobial activity test, ethyl acetate fraction that leaf and fruit excluded seed inhibited higher 19, 15 mm and 16, 15 m in clear zone far Staphylococcus aureus and Escherichia coli in each. Ethyl acetate fraction that extracted from a series of polar and nonpolar solvent fractionation of methanol extracts showed better results in the hydrogen donating activity of 82% in leaf, 74% in seedless fruit, 68% in seed, 52% in peel and 30% in fresh.

• Biomedical Science Letters
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• v.17 no.1
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• pp.21-25
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• 2011

We have analyzed 11 different commercial brands provided by Daboo Culture and Art Center. This study was carried out to determine the antibacterial activity of water extract from puer tea ingredients against Staphylococcus aureus (S. aureus) and Listeria monocytogenes (L. monocytogenes). Antibacterial activity of the water extracts was shown against S. aureus and L. monocytogenes by paper disc method. In case of S. aureus, antibacterial activity of the extracts appeared as clear inhibitory zone. This antibacterial activity was greater along with pH and showed the highest effect at pH 10. In case of L. monocytogenes, antibacterial activity of the extract appeared as clear inhibitory zone. Some Puer tea appeared to be more powerful in antibacterial activity against S. aureus and L. monocytogenes. The polyphenol compounds were 3.46~8.68%, depending upon samples. In conclusion, puer tea is considered as a good choice for well-being food.

• Journal of Korean Biological Nursing Science
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• v.23 no.1
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• pp.1-10
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• 2021

Purpose: To verify the anti-microbiotic activity and to develop eco-friendly surface disinfectants using the Opuntia ficus-indica extract. Methods: The stem and fruits of the Opuntia cultivated in Jeju Island were extracted with hot water, 70% EtOH and 100% MeOH, respectively. To examine the antimicrobial activity of the extracts, gram positive bacteria (Bacillus subtilis, Staphylococcus aureus), gram negative bacteria (Escherichia coli, Salmonella typhimurium), yeast (Candida albicans), mold (Aspergillus flavus) and antibiotic resistant bacteria (E. coli, S. aureus) were measured to form a clear zone. Results: The antibacterial activity of the fruit extract was higher than that of the stem extract, and the antibacterial activity of the 100% MeOH (FM) extract and the 70% EtOH (FE) extract of the palm cactus fruit was suitable for the surface disinfectant overall, and clear-zone formed even at relatively low concentrations (250 mg/mL). The FM and FE have antibacterial activity against various bacteria, therefore they can be used as disinfectants. Conclusion: The antimicrobial activity of Opuntia ficus-indica extract from Jeju Island by stem and fruit was determined at relatively low concentrations (250 mg/mL). The Opuntia ficus-indica extract will be useful for surface disinfectants dissolving the patients' bath, oral gargling, and powdered powder in water or ethanol in appropriate concentrations.