• Korean Journal of Pharmacognosy
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• v.38 no.4
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• pp.372-375
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• 2007

Reactive oxygen species(ROS) or free radicals are produced in the pathogenesis of human diseases including atherosclerosis, diabetes, cancer, and aging. Antioxidants are associated with the prevention of ROS-induced tissue and cellular damage in the various diseases. This study investigated the antioxidative activities of the methanol extract of Alisma plantagoaquatica var. orientale and its main component under conditions of radical generation using allophycocyanin and ferric-thiocyanate assay. Alisol B 23-acetate as a main component was isolated from the methanol extract of Alisma plantago-aquatica var. orientale. In results, the extract of Alisma plantago-aquatica var. orientale showed inhibitory activity on AAPH [2,2'-azobis(2-amidinopropane)dihydrochloride]-induced protein oxidation. Also, the extract of Alisma plantago-aquatica var. orientale and alisol B 23-acetate inhibited lipid peroxidation. These results indicate that Alisma plantago-aquatica var. orientale and alisol B 23-acetate show promise as therapeutic agents for various damages involving free radical reactions.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.9
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• pp.1309-1316
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• 2003

A premixed-compression-ignition engine has been studied to improve the efficiency and to decrease exhaust emissions. However those systems have some difficulties for controlling combustion process. Radical is an activated chemical species formed by a chemical chain reaction between reactant and product. When the chain reactions occur, the energy bond of species is broken easily by the released radicals. The combustion chamber of the premixed-compression-ingnition engine is consist of a main chamber with lean premixture and a subchamber with rich premixture. Those are connected by narrow cylinderical connections. With ignition start in the subchamber, many different kinds of radical is jetted into the main chamber. The premixed gas in main chamber is quickly burned up by the radical ignition in multi-pionts. In this paper, the combustion phenomena in a constant volume combustor having a radical injector are numerically analyzed. The some constants in the reaction rate equation are adjusted by the experimental results tested in the same geometrical chamber. The code is applied on the two combustors in a wide range of equivalence ratio. The results show that the burning time is much shorter in the combustor having radical injector.

• Journal of Species Research
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• v.3 no.2
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• pp.123-126
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• 2014

We present a list of the beetle species associated with the oyster mushroom, Pleurotus ostreatus Fr. in the birch forest of Onon-Balj National Park in Mongolia. A total of 21 species in seven families were found in this fungus, including fungivorous species: Litargus japonicus Reitter and Mycetophagus antennatus (Reitter) (Mycetophagidae), Pseudamblyopus similis (Lewis) (Erotylidae), and Lordithon sp. (Staphylinidae) etc. Both adult and larval forms are presented in the checklist along with the type of fungal association, of which approximately 52 percent are obligate mycetobionts. The main trends of the ecological and trophic specialization of the mycetophilic beetles are discussed.

• ALGAE
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• v.20 no.4
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• pp.305-314
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• 2005

5 Haptophyta 2 Chrysophyta and 1 Prasinophyta species of scale-bearing nanoflagellates were collected in coastal water of Korea and identified by examination of their scales with Field Emission Scanning Electron Microscope (JSM-6700F). These included Chrysochromulina ahrengoti, C. simplex, C. spinifera, Prymnesium parvum, P. patelliferum, Mamiella gilva, Paraphysomonas imperforata and Pa. vestita. The surface of cells covered with unmineralised scales (5 Haptophyte and 1 Prasinophyta species) or silica scales (2 Chrysophyta species). Scale-covered flagella are found in the 1 Prasinophyta species. One of the main structural characteristics of Haptophyte is the haptonema, a filiform organelle which occurs together with the two flagella. It may be long and coiling upon irritation as in Chrysochromulina, or short and noncoiling as in Prymnesium.

• Korean Journal of Microbiology
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• v.7 no.3
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• pp.91-106
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• 1969

From a review of the literature it was found that 96 species of fungi have been reported as occurring on the wood of Ulmus americana L., the Amercan elm. In an intensive study of the fungi growing on one American elm log, 60 species were found. Only one had been reported previously on American elm. A second fungus proved to be a hyperparasite of a slime mold. Three members of the Fungi Imperfecti could not be identified and is believed that they may constitute new taxa. In the past, Nasidiomycetes constituted the main group of fungi on American elm wood according to the literature. The Fungi Imperfecti were the largest group in this study in that over half of the species found are imperfect fungi. All of the species encountered in the study were illustrated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.266-269
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• 2001

This paper investigated the aging characteristic under long-term corona discharge on roan temperature vulcanized silicone rubber, which has been using as a protective coating material for solving the contaminant problem. The applied electrical field is 10kV/cm ac and corona discharge treatment was applied on RTV silicone rubber sheet for maximum 250 hours. With the duration of corona discharge. the diffusible low molecular weight species increased, which was determined the usage of n-hexane extraction method. In addition, the contaminant layer was formed on the treated surface, and then measured the contact angle. We investigated the relation of contact angle and diffusible low molecular weight species. It is found that scissor of main chain PDMS and side chains $(CH_3)$ and the generation of LMW species were occurred by a corona discharge. The improvement of hydrophobicity rate is thought due to the increase of diffusible LMW species.

• Journal of the Korea Furniture Society
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• v.22 no.2
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• pp.132-139
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• 2011

Wood-anatomical studies on vines, one of the main materials for fork craftworks used in the past, were insufficient compared to those for trees. Therefore, it is important to identify the species of vines in order to preserve the vinery craftwork relics. In this study, the species of 31 samples (30 traditional baskets and one sculpture relic) obtained from Korea were identified. Twenty-two baskets among 30 baskets were identified as Cocculus trilobus DC, a perennial vine which has flexible xylem and thick fibers in phloem. The other baskets were identified as $Lespedeza$ spp., a shrub with tough xylem. The sculpture part was $Actinidia$ $arguta$ Planch., a perennial vine with chambered piths.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.266-269
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• 2001

This paper investigated the aging characteristic under long-term corona discharge on loon temperature vulcanized silicone rubber, which has been using as a protective coating material for solving the contaminant problem. The applied electrical field is 10kV/cm ac and corona discharge treatment was applied on RTV silicone rubber sheet for maximum 250 hours. With the duration of corona discharge, the diffusible low molecular weight species increased, which was determined the usage of n-hexane extraction method. In addition, the contaminant layer was formed on the treated surface, and then measured the contact angle. We investigated the relation of contact angle and diffusible low molecular weight species. It is found that scissor of main chain PDMS and side chains (CH$_3$) and the generation of LMW species were occurred by a corona discharge. The improvement of hydrophobicity rate is thought due to the increase of diffusible LMW species.

• Proceedings of the KSFDT Conference
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• 2006.04a
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• pp.93-98
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• 2006

• Proceedings of the KSFDT Conference
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• 2006.04a
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• pp.183-186
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• 2006