• Title/Summary/Keyword: natural medium

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The Actual Condition and Problems of Current Shrouds (현행수의의 실태 및 문제점)

  • 조효숙;안지원
    • Journal of the Korean Society of Costume
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    • v.52 no.3
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    • pp.123-137
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    • 2002
  • The purpose of this study is to analyze the actual condition and problems of current ready-made shrouds. Current shrouds were formed after the 20th century and therefore are quite apart from its traditional precedents of Chosun Dynasty. In this respect, several problems can be pointed out. 1. The use of natural colored hemp as a primary textile of current shrouds is far from our tradition. Silk, ramie, and cotton have to be used together with hemp. Also, more variety of colors can be used other than natural white. 2. The size of ready-made shrouds has to be categorized at least into three: large, medium and small 3. The pattern and sowing method of Dopo(도포) and Wonsam(원삼) should be corrected in line with those of the traditional Dopo(도포) and Wonsam(원삼). 4. The design and items of current ready-made shrouds have to break away from the standardized convention and should seek more of a variety that our rich tradition provide. 5. The rational index should be suggested so that consumers can compared the quality and price of ready-made shrouds available at their hands.

Role of Unstable Phenanthrene-Degrading Pseudomonas species in Natural Attenuation of Phenanthrene-Contaminated Site

  • Prakash, Om;Lal, Rup
    • Microbiology and Biotechnology Letters
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    • v.41 no.1
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    • pp.79-87
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    • 2013
  • An unstable yet efficient phenanthrene-degrading bacterium strain Ph-3 was isolated from a petroleum-contaminated site at the Mathura Oil Refinery, India. The strain was identified as Pseudomonas sp. using a polyphasic approach. An analysis of the intermediates and assays of the degradative enzymes from a crude extract of phenanthrene-grown cells showed a novel and previously unreported pattern of 1, 2-dihydroxy naphthalene and salicylic acid production. While strain Ph-3 lost its phenanthrene- degrading potential during successive transfers on a rich medium, it maintained this trait in oligotrophic soil conditions under the stress of the pollutant and degraded phenanthrene efficiently in soil microcosms. Although the maintenance and in vitro study of unstable phenotypes are difficult and such strains are often missed during isolation, purification, and screening, these bacteria constitute a substantial fraction of the microbial community at contaminated sites and play an important role in pollutant degradation during biostimulation or monitored natural attenuation.

Effect of 2-NBDG, a Fluorescent Derivative of Glucose, on Microbial Cell Growth

  • Shin, Dong-Sun;Oh, Ki-Bong
    • Journal of Microbiology and Biotechnology
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    • v.12 no.5
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    • pp.834-837
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    • 2002
  • A fluorescent glucose analogue,2-[N-(7-nitrobenz-2-ox a-1,3-diazol-4-yl) amino] -2- deoxy-D-glucose (2-NBDG), which had previously been developed for the analysis of glucose uptake in living cells, was investigated to determine its biological activity on microorganisms.2-NBDG did not show any inhibitory effect on growth of yeast cells and bacteria. In contrast, 2-NBDG exhibited strong inhibitory effects on filamentous fungal growth. The growth of filamentous fungi was completely inhibited, when 2-NBDG was supplemented as sole carbon source. The inhibitory effect was decreased by the addition of glucose in the test medium. Furthermore, 2-NBDC inhibited chitinase activity of Trichoderma sp. These results suggested that the inhibitory effects of 2-NBDG on filamentous fungi might be partially due to the inhibition of chitinase.

An Experimental Study on the Thermal Behavior of Aquifer Thermal Energy Storage System (대수층 축열시스템의 열거동에 관한 실험적 연구)

  • 이세균;문병수;남승백;김기덕
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.9
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    • pp.1780-1787
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    • 1992
  • Experiments have been performed on the thermal behavior in a liquid saturated porous medium in a system to simulate a single well aquifer thermal energy storage system. The principal interests in this study are the combined effects of forced and natural convection. Significant buoyancy flow due to natural convection is developed quickly as the temperature difference between the injection and original aquifer temperature increases. Theoretical model under simplified assumptions (called simple buoyancy flow model in this study) has been developed. The results of this model agree well with the experiments. The effects of buoyancy flow on the recovery factor are also examined in this study.

Performance Comparison between Expressnet and FDDI for intergrated Voice and Data Traffic (음성과 데이터의 통합트래픽에 대한 Expressnet과 FDDI의 성능비교)

  • Joo, Gi-Ho
    • The Journal of Natural Sciences
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    • v.8 no.2
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    • pp.93-99
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    • 1996
  • In this study, we compare performance of priority schemes of FDDI and Expressnet for integrated voice and data traffic through simulation. The voice capacity of FDDI is higher than that of Expressnet for all cases considered. When compared to Expressnet, FDDI achieves a higher data throughput for file transfer traffic but it incurs a longer delay for interactive traffic.

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Saponins from the Callus Mass of Phytolacca americana

  • Chi, Hyung-Joon;Kim, Hyun-Soo
    • Archives of Pharmacal Research
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    • v.8 no.1
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    • pp.15-20
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    • 1985
  • Strong anti-inflammatory saponins Phytolacca americana (Phytolaccaceae) wereobtained from callus mass derived from the stems and also from that derived from the roots of cultivated Phytolacca americana (which were designated as PAS and PAR, respectively). The callus were grown on Linsmair and Skoog's agar medium supplemented with 1ppm OF 2, 4-dichlorophenoxyacetic acid. Phytol accoside B and D were obtained from PAS and phytolaccoside A and B from PAR. The thin layer chromatograms of the crude saponins from PAS and PAR were similar to those of original plants. PAS contained phytolaccoside B as a major component while phytolaccoside E was a major saponin in original plants.

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Vibration analysis of steel frames with semi-rigid connections on an elastic foundation

  • Vu, Anh Q.;Leon, Roberto T.
    • Steel and Composite Structures
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    • v.8 no.4
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    • pp.265-280
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    • 2008
  • An investigation on the combined effect of foundation type, foundation flexibility, axial load and PR (semi-rigid) connections on the natural frequencies of steel frames is presented. These effects were investigated using a suitable modified FE program for cases where the foundation flexibility, foundation connectivity, and semi-rigid connections could be treated as equivalent linear springs. The effect of axial load on the natural frequency of a structure was found to be significant for slender structures subjected to high axial loads. In general, if columns of medium slenderness are designed without consideration of axial load effects, the frequency of the structure will be overestimated. Studies on the 3-story Los Angeles PR SAC frame indicate that the assumption of rigid connections at beam-column and column-base interfaces, as well as the assumption of a rigid foundation, can lead to significant errors if simplified design procedures are used. These errors in an equivalent static analysis are expected to lead to even more serious problems when considering the effect of higher modes under a non-linear dynamic analysis.

Influence of Aging Media and Filler System on Recovery Behaviors of Natural Rubber Composites (노화 매질과 충진 시스템이 천연고무 복합체의 회복 거동에 미치는 영향)

  • Choi, Sung-Seen;Kim, Ok-Bae
    • Elastomers and Composites
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    • v.47 no.2
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    • pp.156-161
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    • 2012
  • Difference in recovery behaviors from the circular deformation of natural rubber (NR) composites aged in air and distilled water, respectively were investigated. Recoveries of the samples aged in air were larger than those of the samples aged in distilled water. Recovery rates of the samples reinforced with filler were faster than those of the unreinforced ones. Recovery rates of the carbon black-filled samples were faster than those of the silica-filled ones. Difference in the recovery behaviors according to the aging media can be explained by the crosslinking density changes and the annealing effect.

Determination of Mercury in Korean Mussels (Mytilus coruscus) for Marine Environmental Monitoring (연안환경 모니터링을 위한 홍합(Mytilus coruscus)의 체내 수은 함량 분석)

  • Lee, Soo Yong;Lee, Jangho
    • Journal of Environmental Science International
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    • v.27 no.12
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    • pp.1291-1298
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    • 2018
  • Marine ecosystems are frequently exposed to a variety of chronic and acute pollutants derived from anthropogenic production and consumption activities. Mussels are sessile (can provide location-specific information), medium-sized (have enough tissue matrix for chemical analysis) filter-feeders (show accumulation of pollutant chemicals from seawater). These biological and ecological characteristics make mussels virtually ideal for pollution monitoring. In this study, Korean mussels (Mytilus coruscus) were collected from nine different sites situated along the coasts of the western sea to the eastern sea of Korea in 2017. Total mercury concentration was highest (mean ${\pm}$ standard error, $92.7{\pm}3.5ng/g\;dry$) on Baengnyeongdo Island in the western sea, and the sites in the southern sea showed the lowest mean concentrations (42.3 - 44.5 ng/g dry). These results were discussed in terms of possible pollution sources.

Nonlocal thermal vibrations of embedded nanoplates in a viscoelastic medium

  • Zenkour, Ashraf M.
    • Structural Engineering and Mechanics
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    • v.82 no.6
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    • pp.701-711
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    • 2022
  • The nonlocal elasticity as well as Mindlin's first-order shear deformation plate theory are proposed to investigate thermal vibrational of a nanoplate placing on a three-factor foundation. The Winkler-Pasternak elastic foundation is connected with the viscous damping to obtain the present three-parameter viscoelastic model. Differential equations of motion are derived and resolved for simply-supported nanoplates to get their natural frequencies. The influences of the nonlocal index, viscous damping index, and temperature changes are investigated. A comparison example is dictated to validate the precision of present results. Effects of other factors such as aspect ratio, mode numbers, and foundation parameters are discussed carefully for the vibration problem. Additional thermal vibration results of nanoplates resting on the viscoelastic foundation are presented for comparisons with future investigations.