• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.7-10
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• 2009

The development and evaluation of solid propellant were performed for the turbopump pyro starter, which start up the liquid propellant rocket engine for the Space Launch Vehicle (SLV). Requirements for the turbopump pyro starter propellant include the production of low flame temperature, low burning rate and nontoxic gas to protect the mechanical corrosion or air pollution. This study describes the development of the solid propellant composition which is based on PCP binder. DHG (Dihydroxy glyoxime), which has advantages of oxygen balance and ignition, was used as coolant. The mechanical properties and burning rate of the propellants were measured. Finally, static fired test was performed to prove the possibility of development.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.181-184
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• 2009

A development of a composite solid propellant is carried out for an application to gas generators as an energy source of rocket system. With HTPB as a propellant binder which has 80% of particle loading ratio, a favorable rheology, and moderate curing properties at the range of $-50^{\circ}C{\sim}70^{\circ}C$, AN is selected as the first kind of oxidizer having the characteristics of a low flame temperature, minimal particle residual as well as nontoxic products. AP is the second oxidant for ballistic property control. A series of experiments for the improvement of physical properties were conducted and resulted in the propellant formulation having 30% of strain rate at 8 bar of max. stress.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.769-772
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• 2000

Fish oil has abundant highlly unsaturated fatty acids such as EPA and DHA. Therefore, fish oil is very susceptible to peroxidation. Adding any antioxidants to fish oil is acceptable to prevent the peroxidation. However, nontoxic and strong naturally occurring antioxidants for fish oil was not developed. ${\alpha}-tocopherol$ is one of useful natural antioxidants, but it is not good to prevent the fish oil peroxidation. In this study, we examined the development of microencapsulated squid liver oil product to prevent effectively peroxidation of the fish oil. The acceptable materials for encapsuling the squid liver oil were gum arabic and gelatin. The ultimate encapsulation rate of squid liver oil was 45.5%.

• KSBB Journal
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• v.32 no.2
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• pp.160-167
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• 2017

Coating of individual cells with organic or inorganic materials has drawn a great deal of attention, because it provides the cells with physicochemical durability, which would contribute to the development of bioreactors, biosensor, and lab-on-a-chip, as well as to the fundamental studies in single cell-based biology. Although many strategies have been developed for coating of microbial cells, limited methods are available to coat mammalian cells because most mammalian cells do not have a robust membrane or exoskeleton. Instead, they are enclosed in a lipid bilayer, which is fluidic and vulnerable to changes in its environments. It is more difficult to treat mammalian cells in vitro than microbial cells because the surfaces of mammalian cells are not protected or reinforced by a tough coat. In this work, we report a cytocompatible and degradable nanocoat for mammalian cells. Three types of mammalian cells (HeLa cells, NIH 3T3 fibroblasts, and Jurkat T cells) were individually coated within metal-polyphenol. To maintain the viability of the mammalian cells, we performed the whole processes under strictly physiological culture conditions, and carefully selected nontoxic materials.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.3
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• pp.415-420
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• 2001

Eighteen kinds of medicinal edible herbs, which are nontoxic and has been widely used in traditional folk medicine, were extracted and antimicrobial activity of the extracts was investigated against various foodborne pathogens or food poisoning microorganisms. Among them, the ethanol extract of Quercus mongolica showed the strongest antimicrobial activities against Gram positive and Gram negative bacteria and followed by Quercus aliena and Quercus dentata, respectively. Thus, further study was conducted to determine the antimicrobial activity of Quercus species extracts. The plants were extracted with ethanol, methanol and water, respectively. The ethanol, methanol, and water extracts of Quercus mongolica leaf showed 10~21 mm inhibition zone against Gram positive and Gram negative bacteria at two thousand $\mu\textrm{g}$ per disc, but little antimicrobial activity was observed against fungi and yeast. The minimal inhibitory concentrations (MIC) of the ethanol extract of Quercus mongolica leaf was 250$\mu\textrm{g}$/mL against Bacillus cereus. Salmonella typhimurium, and Pseudomonas aeruginosa and 62.5~125 $\mu\textrm{g}$/mL against Staphylococcus aureus and Listeria monocytogenes, respectively.

• Journal of Environmental Health Sciences
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• v.31 no.5 s.86
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• pp.444-450
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• 2005

The present study was designed to investigate whether traditional Korean fermented soybean paste(doen-jang) and soybean extracts have inhibitory effects on the growth of KB cell, an oral epithelioid cancer cell. When KB cell ATCC CCL-17 was cultivated for 48 flours with the addition of 0.5% of the five types or doen-jang extract, the growth of KB cell was inhibited by all types of extract, and ethyl acetate extract showed the highest inhibitory effect. In case of soybean extract, all types of extract also showed KB cell inhibitory effects, however, generally less than those of doen-jang extract. When ethyl acetate extract of doen-jang was added in different concentrations and KB cell was cultivated for 24 hours and 45 hours, strong inhibitory effect began to appear from the concentration of 1.25 mg/ml. Although soybean extract showed such a tendency, its effect was lower than that of doen-jang extract. These results indicate that doen-jang extract has inhibitory effect against KB cell, and particularly ethyl acetate extract has the highest effect. The effect of doen-jang extract might be possibly enhanced by the fermentation of soybeans. It is assumed that doen-jang extract may be used to develop nontoxic medicines for preventing and treating oral diseases.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.27 no.1
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• pp.3-15
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• 2001

The bilayer forming ability of pseudo-ceramide PC104 in octanoic acid/water/n-octyl $\beta$-D-glucoside mixtures was investigated through the phase diagram. Because of its low solubility in water and of its crystallization, pseudoceramide PC104 was dissolved in octanoic acid, which is nontoxic additive for foods and cosmetics. The mixtures formed four different phases (L1, L2, LC and two phases). Depending on the concentration of PC104 in octanoic acid, the region of each phase was extended or contracted. On the contrary to the region of L2, regions of lamellar phase and L1 phase were expanded. The bilayer-forming ability of PC104 was explained on the basis of concentration of PC104 at interface and interaction between PC104 and octanoic acid. From FT-IR results, it was found that the interactions of PC104’s polar head group with octanoic acid increased as the amount of PC104 in octanoic acid increased. Also emulsion size and size distribution have been studied depending upon the emulsification path. droplets of emulsion prepared from lamellar phase were smaller and more homogeneous compared to those of emulsions formed from L2 phase.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2005.05a
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• pp.241-244
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• 2005

The aim of this study was to determine the first outbreaks of nontoxic Gonyaulax polygramma Stein in Yeosu waters in place of harmful Cochlodinium polykrikoides Margalef, which has occurred annually in the same coastal region since 1995. The observation of cellular arrangement and structure by electron microscopy showed that G. polygramma isolated from Yeosu waters had a few spines connecting with mem-branes and prominent longitudinal ridges on the cell surface, with a cingular dis-placement 1.5 times their cell width. Furthermore, the location of the nucleus wasposterior of large oval formation according to electron microscopy. On 6 August, 2004,the first bloom of G. pozygramma occurred, the date of own its disappearance was with a maximum cell density of 8,000 cells ml$^{-1}$ on 21 August, 2004. During the period of this study, the horizontal distribution of sea water temperature and salinity showed a strong coastal front, whereas the front of DIN (Dissolved Inoganic Nitrogen) was significantly different between the occurrence and disappearance of G. polygramma blooms. These results suggested that the process of the breakdown of stratification by wind and a low level of inorganic nitrogen play important roles in the rapid growth of G. polygrmma, which is associated with a greater robustness in growth against DIN than that of C.polykrikoides in nature.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3343-3352
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• 2014

Chemoprevention is an attempt to use nontoxic natural and synthetic substances or their mixtures to intervene the relatively early stages of carcinogenesis, before invasive characteristics are manifested. The consumption of fruits is well known to reduce the risk of human cancers. Although most fruits are available only on a seasonal basis, recent advances in food processing technologies have made it possible to extend the shelf life of fruits and fruit-products. Fruits can be preserved by applying different drying processes to reduce the moisture content. Different varieties of dried fruits are now sold in supermarkets, thereby making them readily accessible to consumers. Since oxidative stress and chronic inflammation play important roles in cancer development, dried fruits with antioxidative and anti-inflammatory properties hold promise for cancer chemoprevention. The antioxidant, anti-inflammatory and chemopreventive activities of dried fruits are largely attributed to their polyphenols and vitamins. Dried fruits contain adequate amounts of bioactive principles, such as anthocyanins, acetogenins, catechins, coumarins, phenolic acids, terpenes, xanthones, and others. Since numerous health beneficial phytochemicals in fruits are conserved even after processing, regular intake of dried fruits can help prevent cancer. This review addresses the chemopreventive potential of representative dried fruits and their active constituents.

• The Korea Journal of Herbology
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• v.21 no.3
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• pp.35-45
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• 2006

Objectives : The plans can be used for medicinal purposes among Alismatales in korea and examined their effects and distributions. Methods : The examined herbalogical books and research papers which published at home and abroad. Results : 1. There were totaled to 15 genera and 45 species in Alismatales in Korea and among them medicinal plants are 8 genera, 17 species, some 38% in total. 2. Potamogeton genus is main kind enough that it has 14 species among 45 species in the Alismatales , of which medicinal plants are 6 species. 3. The herb is the main medicinal parts of medicinal plants in the Alismatales which is used in 14 species. 4. According to nature and flavor of medicinal plants in the Alismatales , they were classified into cool 8 species; sweet taste 10 in the order. 5. According to meridian propism of medicinal plants in the Alismatales, they were classified into liver meridian 8 species. 6. According to the properties and principal curative action, they were classified into drugs for antifebrile 12 species, drugs for detoxicant 11 , drugs for drain damp 9 in the order. 7. It was noticed that every medicinal plant in the Alismatales is nontoxic. Conclusion : There were totaled to 15 genera and 45 species in Alismatales in Korea and among them medicinal plants are 8 genera, 17 species, some 38% in total.