• Macromolecular Research
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• v.17 no.11
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• pp.856-862
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• 2009

This study examined the effects of liquid and solid additives on the morphological, mechanical and thermal insulating properties of rigid polyurethane foams (PUFs). The PUFs synthesized with tetramethylsilane (TEMS) as a liquid-type additive showed a smaller average cell size and lower thermal conductivity than those with the aerosil 200 and clay 30B as solid-type additives. When TEMS was added, the average cell size of the PUF became more uniform and finer due to the reduced surface tension of the polymer solution, which increased the nucleation rate and number of bubbles produced and reduced cell size. The PUFs with TEMS showed the highest closed cell contents among the PUFs prepared using TEMS, aerosil 200 and clay 30B. This suggests that the insulation properties of PUF can be determined by both the size of the cell structure and the amount of closed cell contents in the system. The compression and flexural strengths of the PUF increased slightly when the aerosil 200, clay 30B and TEMS were added compared those of the neat PUF. The reaction profiles of the PUFs showed a similar gel and tack tree time with the reaction time among the PUFs synthesized with three different additives and neat PUF. This suggests that the nucleating additives used in this study do not affect the bubble growth of the chemical reaction, and the additives may act as nucleating agents during the formation of PUF. From the above results of the cell size, thermal conductivity, closed cell contents and reaction profile of the PUFs, liquid-type nucleating agent, such as TEMS, is more effective in decreasing the thermal conductivity of the PUF than solid-type nucleating agent, such as aerosil 200 and clay 30B.

• Food Science and Preservation
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• v.13 no.4
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• pp.501-505
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• 2006

This study was carried out to investigate the antioxidative activity and cytotoxicity on human KB cell of extract from Rhododendron mucronulatum flower, and also to determine the contents of total polyphenol and flavonoid. The methanol extract of Rhododendron mucronulatum flower was fractionated with various solvents such as hexane, chloroform, ethyl acetate, butanol and water. The DPPH radical scavenging activities of ethyl acetate fraction had stronger activity than other fractions. So, antioxidative substances of ethyl acetate fraction were crude purified by silica gel column chromatography. The DPPH radical scavenging activities of crude purified fraction 2 and 3 were more than 90% at 40 ppm. In the presence of $100{\mu}g/mL$, growth inhibition on human KB cell by WST-1 assay showed 81.2% in chloroform fraction and 74.6% in hexane fraction. The contents of total polyphenol and flavonoid of ethyl acetate traction were 32.70% and 20.30%, respectively, The antioxidative activity showed correlation with total polyphenol and flavonoid contents.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.7
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• pp.935-940
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• 2001

To determine the effect of different growth stages and cultivars on the chemical composition of sorghum plant and its morphological fractions, samples of whole plant, leaf and stem of J.S-263, J.S-88 and Hegari cultivars, harvested at various growth stages were drawn for analysis. All the samples were analysed for their dry matter contents and various cell wall components such as NDF, ADF. hemicellulose, cellulose, lignin, cutin and silica. Significant increase in DM contents of whole sorghum plant, leaf and stem was observed with advancing stage of growth. The highest DM content was recorded in leaf fraction of the plant. All the cell wall constituents increased significantly in whole sorghum plant, leaf and stem as the plant matured. The maximum NDF, ADF, cellulose and lignin contents were observed in stem fraction, followed by whole plant. However, the hemicellulose, cutin and silica contents were higher in leaf fraction of the plant. The cultivars were found to have some effect on the chemical composition of whole plant, leaf and stem fractions. The results indicated that plant maturity had a much greater effect on the chemical composition of sorghum plant, whereas it was little affected by cultivars.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.3
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• pp.366-370
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• 1999

Samples of whole plant, leaf and stem of Akbar, Neelum, UM-81 and lZ-31 cultivars of maize fodder harvested up to 14 weeks at different growth stages were drawn and analysed for dry matter contents and various cell wall constituents such as NDF, ADF, hemicellulose, cellulose, lignin, cutin and silica. The dry matter contents of whole maize plant, leaf and stem increased significantly (p<0.01) with advancing plant age. Maximum dry matter was found in the leaf fraction of the plant. The cell wall components continued to increase significantly (p<0.001) in whole maize plant and its morphological fractions as the age advanced. Maximum values for NDF, ADF, cellulose and lignin were observed in stem followed by whole plant and leaf, whereas hemicellulose, cutin and silica contents were higher in leaf fraction of the plant. The cultivars were observed to have some effects on chemical composition of all plant fraction. The results indicated that maturity had a much greater effect on the concentration of all the structural components than did the cultivars. It was concluded that maize fodder should be cut preferably between 8th to 9th week of age (flowering stage) to obtain more nutritious and digestible feed for livestock. Among the maize cultivars, Neelum proved to be the best, due to its higher dry matter contents and lower lignin concentration.

• Proceedings of the Korea Contents Association Conference
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• 2006.05a
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• pp.189-192
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• 2006

An important application domain for online services is an interactive, multiplayer game. in recent, many increase of users that use on-line services through networks have caused a heavy load to the server. In this paper, we propose a MMORPG distributed game server using 2Layer-Virtual Cell. Our method provides more effective solution of MMORPG distributed game server for large numbers of users.

• Proceedings of the Korea Contents Association Conference
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• 2006.05a
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• pp.405-408
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• 2006

Design of appropriate control schemes that can satisfy the cell loss, delay requirements with various traffic specification for B-ISDN is an extremely important challenging problem. In this paper, we proposes a priority control scheme with a window counter and a cell counter per each type of class. The priority control for satisfying required service quality is performed with delay/loss factor obtained by comparing window counter with cell counter. The performance of proposed control scheme is estimated by computer simulation.

• Proceedings of the Korea Contents Association Conference
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• 2014.11a
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• pp.209-210
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• 2014

질염 환자의 Pap. 염색 도말 표본에서 실마리세포(clue cell)는 쉽게 관찰되었으며 이들 세포 주변에서 젖산균(lactobacilli)은 확인되지 않았다. 주사전자현미경상에서 편평상피세포(squamous epithelial cell) 표면을 덮고 있는 Gardnerella vaginalis들은 biofilm을 형성하고 있었다. 무정형의 biofilm 물질은 세균 표면을 매끄럽게 덮고 있거나 세균과 세균 사이를 연결시켜주고 있었다. Gardnerella vaginalis는 구균과 간균의 형태로 직경이 약 $0.3{\mu}m-0.6{\mu}m$ 크기로 다양하였으며 세포벽 표면에는 작은 돌출된 물질들에 의해서 피복되어 있고, 일부 세균들은 분열양상을 나타냈다.

• The Korean Journal of Food And Nutrition
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• v.5 no.2
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• pp.111-115
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• 1992

To examine ripening in peach types, cell wall contents and polygalacturonase activity were compared in Changbang, Daegubo and Yumyung peaches. Among peach types, the hardness of Daegubo was the lowest. Yumyung peach had the highest content of alcohol-insoluble substances and Changbang peach of cell wall. The contents of total and insoluble pectic substances were little different between Changbang and Yumyung peach, while the lowest in Daegubo. Daegubo peach had the highest activity of polygalacturonase, Changballg and Yumyung peach in succession.

• International Journal of Contents
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• v.11 no.3
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• pp.34-38
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• 2015

A band stop filter is proposed with cascading unit cells that are based on a dual composite right/left-handed (D-CRLH) conductorbacked coplanar waveguide. The parameters of the unit cell have been analyzed to confirm the behavior of each component for the equivalent circuit of the cell. We simulated the dispersion characteristics and energy distribution and have determined that the unit cell has a D-CRLH property. The band stop filter was implemented by symmetrically cascading two of the proposed unit cells. The experimental results for the band stop filter revealed a band rejection performance of 32 dB and a return loss of 0.35 dB in the stopband frequency range from 869MHz to 954MHz. Finally, we show that there is a good agreement in the experimental results and those obtained through the simulations.

• Applied Chemistry for Engineering
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• v.26 no.5
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• pp.533-537
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• 2015

Micro-algae Chlorella vulgaris (C. vulgaris) is an important source for bio-diesel because of the high content of neutral lipids. In this study, we intended to induce mutants of C. vulgaris by UV-B irradiation. C. vulgaris was first exposed to UV-B for 1, 2, 3, 4, 5 min. As the UV-B exposure time increased, the cell viability and pigment content were decreased. Mutants of C. vulgaris were also induced through ultraviolet irradiation and two strains were selected with respect to lipid contents, where were named as 'UM10', 'UM15'. They were then cultivated in the same way as to the wild type. After 21 days of cultivation, the cell growth, dry cell weight, pigment contents, and lipid contents were measured for investigating characteristics of mutants. As a result, the cell growth and dry cell weight of both mutants increased about 1.4 and 1.5 times, respectively compared with those of wild type. In addition, chlorophyll and carotenoid contents were measured in order to investigate pigment contents in micro-algae through photosynthesis. It was shown that chlorophyll and carotenoid contents of both mutants decreased about 10% compared to those of wild type. Lipid contents in UM10 and UM15 increased about 1.2 and 1.5 times, respectively compared to that of wild type.