• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.5
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• pp.174-181
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• 1998

Experimental and analytical studies are presented to characterize the break-up mechanism and atomization processes of the intermittent- impinging-type nozzle. Gasoline jets passing through the circular nozzle with the outlet diameter of 0.4mm and the injection duration of 10ms are impinged on each other. The impingement of fuel jets forms a thin liquid sheet, and the break-up of the liquid sheet produces liquid ligaments and droplets subsequently. The shape of liquid sheets was visualized at various impinging velocities and angles using the planer laser induced fluorescence (PLIF) technique. Based on the Kelvin-Helmholtz wave instability theory, the break-up length of liquid sheets and the droplet diameter are obtained by the theoretical analysis of the sheet disintegration. The mean diameter of droplet is also estimated analytically using the liquid sheet thickness at the edge and the wavelength of the fastest growing wave. The present results indicate that the theoretical results are favorably agreed with the experimental results. The size of droplets decreases after the impingement as the impinging angle or the injection pressure increase. The increment of the injection pressure is more effective than the increment of the impinging angle to reduce the size of droplets.

• Microbiology and Biotechnology Letters
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• v.20 no.1
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• pp.1-5
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• 1992

Antibacterial activity of the water-soluble portion of Ulmus pzcmila L. extract against 10 bacterial species was studied by both cylinder plate dilution method and broth dilution test tube method. Inhibitory effect of the extract on the bacteria was also investigated by plotting bacterial survival at various concentration of the extract. The crude extract exhibited antibacterial activity against all of the tested bacterial species with exception of K pneurnoniae. The fractions of the extract prepared by CM Sephadex-C 50 ion exchange chromatography were also subjected to test the antibacterial activity, and the activity was studied after autoclaving for 20 minutes.

• Journal of the Korean Society of Costume
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• v.10
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• pp.51-62
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• 1986

The purpose of this study was to investigate the relationships among Clothing Satisfaction, Social approval, Psychological dependence, and Social security-insecurity and to determine the difference of clothing behaviors by the demographic variables such as age, socioeconomics status, education, religion, and material status. Clothing Satisfaction was measured by Rim's Questionnaire(1974) moditide and supplemented for this study. For the measurement of Social approval and Psychological dependence, the Clothing Interest Inventory developed by Creekmore (1971) was adapted for this story. The measurement for the Social security-insecurity was adapted from Lapitsky's (1961) Social Security Inventory. Data were collected from 322 purposively selected elderly women over sixty dwelling in Seoul by means of interviews. For statistical analysis, frequency distribution, one-way analysis of variance, Pearson's correlation coefficients were used. The results were as follows: 1. There were significant relationships among Clothing satisfaction, Social approval, and Psychological dependence. Negative significant relaionships were found between Clothing satisfaction and Social approval and between Clothing satisfaction and Psychological dependence. 2. There was negative significant relationship between Social security-insecurity and Clothing satisfaction, while positive significant relationships were found between Social security-insecurity and Social approval, and between Social security- insecurity and Psychological dependence. 3. There was significant difference in Clothing satisfaction according to socioeconomic status and education. 4. There was significant difference in Social approval according to socioeconomic statusand education. 5. There was significant difference in Psychological dependence according to education and religion.

• Applied Biological Chemistry
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• v.48 no.4
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• pp.435-439
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• 2005

Antioxidant activity of the ethanol extract from boiled-water of Hizikia fusiformis (EBH) were compared with those of BHA, L-ascorbic acid, gallic acid, caffeic acid and (-)-catechin. The free radical scavenging ability against DPPH (1,1-diphenyl-2-picrylhydrazyl), authentic peroxynitrite and reducing power were measured as indices of antioxidant activity. EBH showed the potent DPPH radical and peroxynitrite scavenging activities, showing 85.23 and 96.97% at final concentration of $1000{\mu}g/ml$, respectively. The reducing power increased with the increasing amount of EBH (final concentration of 1, 10, 100 and $1000{\mu}g/ml$). Total phenolic content of EBH was 588 mg (-)-catechin/g at the final concentration $1000{\mu}g/ml$. Total phenolic contents correlated with DPPH radical scavenging activity $(R^2=0.766)$ and reducing power $(R^2=0.944)$. These results suggested that EBH could be a natural antioxidative source containing antioxidative components.

• Korean Journal of Agricultural Science
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• v.29 no.2
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• pp.91-97
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• 2002

Two phytotoxic compounds, 3-methoxybenzoic acid (MBA) and 3-hydroxy benzoic acid methyl ester (HBAME), were purified and structurally characterized by instrumental analyses from a culture of a phytopathogenic fungus, Bipolaris sorokiniana. During the isolation procedure, the toxic components were monitored by the assay using rice (Echinochloa crusgalli) and Italian ryegrass (Lolium multiflorum). These compounds had a molecular formula of $C_8H_8O_3$ and inhibited the root growth of the plant seedlings over 90% at a level of 1000 ppm. This is the first report of herbicidal activity of MBA and HBAME purified from B. sorokiniana.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.1
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• pp.56-63
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• 2018

In this study, a $100cm^2$ cell frame for a molten carbonate fuel cell was designed using CFD analysis. Electrochemical reactions, gas flow, and the heat transfer in $100cm^2$ cell frame were modeled using COMSOL Multiphysics. Two design variables such as the height of the cell frame and the length of the gas input area were determined to obtain minimized temperature distribution and uniform gas distribution. With two design parameter such as height of the cell frame and the length of the gas flow channel, the temperature difference in the cell fame was decreased to $5^{\circ}C$ and the gas uniformity in the flow channel were achieved.

• ALGAE
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• v.18 no.4
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• pp.349-354
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• 2003

This paper reports that the heavy metal accumulation in marine seaweeds. Algal samples collected from Korean coast were analyzed to determine the concentrations of Cu, Cd, Cr, Zn and Pb. In general, heavy metals were found to be concentrated in many kinds of Korean seaweeds. The concentration levels of accumulated heavy metals in the marine seaweeds was in the following order: Zn > Cu > Cr > Pb > Cd. The concentrations of the heavy metals in the seawater were the highest in Iyajin harbor. Sargassum horneri, a brown alga accumulated high concentrations of Cu (80.66 ${\mu}g{\cdot}g^{-1}$ dw) and Cr (31.54 ${\mu}g{\cdot}g^{-1}$ dw). The high concentrations of heavy metals were accumulated in the brown algae.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.4
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• pp.303-306
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• 2012

Anti-angiogenesis therapy is one of the most promising strategies for the treatment of cancer. We investigated the anti-angiogenesis activity of an extract from the ark shell Scapharca subcrenata and attempted to purify the active compounds. The crude extract of the ark shell inhibited the proliferation of human vein endothelial cells (HUVEC-1) and tube formation by human dermal microvascular endothelial cells (HMEC-1). The methanol extract of the viscera of the ark shell showed activity. The ark shell extract acts as an angiogenesis inhibitor and could be developed further as a health substance, functional food, and anticancer agent.

• Korean Journal of Pharmacognosy
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• v.35 no.3 s.138
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• pp.189-193
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• 2004

In order to find some lead compounds for the treatment of opportunistic infections of malaria and pathogenic microbes, an undescribed Indonesian sponge Agelas sp. collected at Manado, Indonesian Waters, was suggested containing active compounds. Crude ethanolic extract of the sponge exhibited significant in vitro antimalarial and antimicrobial activity against Plasmodium falciparum (D6 colne) with $IC_{5O}$ values of $8\;{\mu}/ml$ and against pathogenic microbes such as Candida albicans $(150\;{\mu}/ml)$, Cryptococcus neoformans $(<20\;{\mu}/ml)$, Staphylococcus aureus $25\;{\mu}/ml$, methicillin-resistant Staphylococcus aureus $(<20\;{\mu}/ml)$, and Pseudomonas aeruginosa $(<20\;{\mu}/ml)$. Active compound (5.0 mg) was isolated from the ethanolic extracts of the sponge and purified by using silica gel and ODS column, successively. Active compound was elucidated as dibromosceptrin $(C_{22}H_{24}Br_2N_{10}O_2)$ by detailed analysis of FTESI-MS and comparison of $^1H,\;^{13}C$, DEPT and HMQC NMR spectral data with those reported.

• International Journal of Highway Engineering
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• v.17 no.5
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• pp.33-38
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• 2015

PURPOSES : The purpose of this paper is to investigate the application of thermoelectric technology to concrete structures for harvesting solar energy that would otherwise be wasted. In various fields of research, thermoelectric technology using a thermoelectric module is being investigated for utilizing solar energy. METHODS: In our experiment, a halogen lamp was used to produce heat energy instead of the solar heat. A data logger was used to record the generated voltage over time from the thermoelectric module mounted on a concrete specimen. In order to increase the efficiency of energy harvesting, various factors such as color, architecture, and the ability to prevent heat absorption by the concrete surface were investigated for the placement of the thermoelectric module. RESULTS : The thermoelectric module produced a voltage using the temperature difference between the lower and upper sides of the module. When the concrete specimen was coated with an aluminum foil, a high electric power was measured. In addition, for the power generated at low temperatures, it was confirmed that the voltage was generated steadily. CONCLUSIONS: Thermoelectric technology for energy harvesting can be applied to concrete structures for generating electric power. The generated electricity can be used to power sensors used in structure monitoring in the future.