• Korean Journal of Microbiology
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• v.36 no.1
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• pp.74-78
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• 2000

Vibrio, Photobacterium, Alteromonas and Xenorhabdus species are capable of emitting light, called bioluminescence. They exist in marine, freshwater and terrestrial environments. Bacterial bioluminescent reaction is that reduced riboflavin phosphates and a long-chain aldehyde are oxidized in the presence of molecular oxygen and enzyme luciferase. This experiment aims to develop the proper culture media and to optimize the storage condition for the recovery of bioluminescent activity in Photobacterium phosphoreum. The Luria broth (LB) medium was modified for cultivation of Photobacterium phophoreum, called as modified LB(mLB) medium. The mLB medium is LB fortified with 3% glycerol and 1.5% NaCl. In mLB medium. bacterial growth and bioluminescent activity are 25% higher than those in a Nutrient broth medium. When the cell stocks were stored at $-20^{\circ}C$, $-70^{\circ}C$ and LN2 for 3 months, cell growth and bioluminescent activity of culture after stored at $-20^{\circ}C$ were better than those of other treatments. The highest bioluminescent activity obtained at the late exponential phase in all treatments. When the cell stock was freeze-dried with 5% adonitol as a cryoprotectant, the recovery of cell was better than those of control and freeze-dried cell stock without addition of cryoprotectant.

• Journal of Biosystems Engineering
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• v.28 no.1
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• pp.45-52
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• 2003

Red ginsengs are inspected manually by examining those in the dark room with back light illumination. Manual inspection is often influenced by physical condition of inspectors. Sometimes. the best grade, heaven. has some inner holes though it was inspected by a specialist. In order to resolve this problem, this study was performed to develop image processing algorithm to detect the inner holes in the x-ray image of ginseng. Because of little gray value difference between background and ginseng in the image. simple thresholding method was not appropriate. Modified watershed algorithm was used to differentiate the inner holes from background and normal ginseng body. Inner hole edge region detected by watershed algorithm consists of many number of blobs including normal portions. With line profile analysis with scanning one line at a time beginning the starting point. it shelved two peaks both ends representing extracting each blobs. in which setting threshold value as of lower peak value enabled us to obtain inner hole image. Once this procedure has to be done till the finishing point it is completing inner hole detection for one blob. Thus. conducting ail blobs by this procedure is completing inner detection of one whole ginseng. Detection results of the inner holes fer various size of red ginsengs were good even though there was small detection variation. 6.2%. according to position of x-rat tube.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.13 no.2
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• pp.75-83
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• 2017

In severe accident conditions of light water reactors, the loss of coolant may cause problems in integrity of zirconium fuel cladding. Under the condition of the loss of coolant, the zirconium fuel cladding can be exposed to high temperature steam and reacted with them by producing of hydrogen, which is caused by the failure in oxidation resistance of zirconium cladding materials during the loss of coolant accident scenarios. In order to avoid these problems, we develop a multi-metallic layered composite (MMLC) fuel cladding which compromises between the neutronic advantages of zirconium-based alloys and the accident-tolerance of non-zirconium-based metallic materials. Cold pilgering process is a common tube manufacturing process, which is complex material forming operation in highly non-steady state, where the materials undergo a long series of deformation resulting in both diameter and thickness reduction. During the cold pilgering process, MMLC claddings need to reduce the outside diameter and wall thickness. However, multi-layers of the tube are expected to occur different deformation processes because each layer has different mechanical properties. To improve the utilization of the pilgering process, 3-dimensional computational analyses have been made using a finite element modeling technique. We also analyze the dimensional change, strain and stress distribution at MMLC tube by considering the behavior of rolls such as stroke rate and feed rate.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.21 no.3
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• pp.47-56
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• 2018

Research was initiated to investigate germination characteristics and germination pattern of 14 herbaceous plant entries used on the road slope during 30 days. An alternative germination condition for 14 herbaceous plant entries required by International Seed Testing Association(ISTA) was applied in the experiment, consisting of 8-hr light at $25^{\circ}C$ and 16-hr dark at $15^{\circ}C$. Significant differences were observed in the first germination rate(0.3%~40.7%)and in the final germination rate(7.7%~93.3%). Days to the first germination(2~8days), days to the 30% germination(2~6days) and days to the peak germination(6~18days) were different among 14 herbaceous plant entries in the study. From this result, we could find out higher final germination rate of 14 herbaceous plant entries in the following order; First, forage crops and cool-season turfgrasses; Second, herbeceous flowers; Third, wild plants. We could also divide germination rate among 14 herbaceous plant entries as 6 groups(I;very high, II;high, III;medium high, IV;medium low, V;low, VI;very low) based on the final germination rate and divide germination speed as 5 groups(A;very fast, B;fast, C;normal, D;slow, E;very slow)based on days to the peak germination. Considering germination characteristics and pattern of 14 herbaceous plant entries Medicago sativa, Lolium perenne, Festuca arundinacea and Cosmos sulphureus were regard as dominating species while Lespedeza cuneata, Silene armeria, Lotus corniculatus var.japonicus, Coreopsis tinctoria and Centaurea cyanus as competitive species following dominating species. However, Chrysanthemum burbankii, Pennisetum alopecuroides, Chrysanthemum boreale., Artemisia princeps var. orientalis and Arundinella hirta were not almost expected to emerge.

• Journal of Animal Environmental Science
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• v.19 no.1
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• pp.55-62
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• 2013

Teff grass is a warm season C4 annual grass that is used for dry hay, silage and haylage. We have developed a high-frequency plant regeneration system for teff grass via callus culture using mature seeds. It was revealed that mature seeds cultured on MS medium supplemented with 2 mg/l 2,4-D, 0.5 g/L proline, 0.5 g/L casamino acid and 3 g/L Gelrite under light condition produced the highest percentage of callus formation (91.9%). Addition of cytokinins (BA) at 0.0~0.5 mg/L to media containing 2 mg/l 2,4-D enhanced callus growth. The most suitable medium for plant regeneration from dehydrated calli was MS agar medium supplemented with 0.1 mg/l NAA, 1 mg/l BA, 0.5 g/L proline, 0.5 g/L casamino acid 3 g/L Gelrite which induced the highest percentage of calli forming shoots (47.0%). The shoots were rooted at the highest rate (100%) when transferred onto 1/2 MS medium and acclimated in greenhouse conditions.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.4
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• pp.175-184
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• 2011

To take advantage of reduced on-site construction periods and minimize traffic impacts various types of steel grid composite deck have been developed since 1930's. Modular prefabricated unfilled grid decks permit a long-distance transportation and construction under unfavorable condition, for example, in mountainous regions due to its comparatively light-weighter structure than fully filled grid deck. In this study bending tests of unfilled grid decks for the deck member of various kinds of infrastructure are carried out, bending strength and behaviour of composite action are experimentally evaluated. In this bending test, design variables are considered, such as type of shear connection between steel grid and concrete slab, spacing between cross bars and thickness of concrete slab. Through test results bending strength and behaviour of composite action are evaluated, reference data for proper type of shear connection and other details of the deck, such as spacing between cross bars, are obtained.

• Journal of the Korean Geotechnical Society
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• v.27 no.12
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• pp.69-84
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• 2011

This paper presents the applicability of NATM Composite Lining method in domestic tunnel construction sites. Firstly, in order to produce high quality PC Panel, optimal steam curing condition is reviewed. And in preparation for fire inside the tunnel, the fire-resistance test of PC Panel is carried out. The constructability of NATM Composite Lining method and the drainage ability of light-weight foamed mortar is also evaluated through field construction test. And PC Panel combination program is developed to calculate the quantity of PC Panel efficiently. Besides, economic evaluation for NATM Composite Lining method is conducted. From this research, it is clearly found that NATM Composite Lining method is applicable to domestic tunnel construction site.

• Textile Coloration and Finishing
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• v.21 no.4
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• pp.23-32
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• 2009

The objective of this study is to investigate the efficacy of leaf powder colorants as substitutes for traditional indigo dyeing. Leaf powder colorants were prepared by hot air($50^{\circ}C$) and room temperanrre($25^{\circ}C$) drying methods from fresh leaves. The presence of indigo in the leaf powder colorants was confirmed by UV/Visible absorption spectra. All the powder colorants showed broad absorption at 602 nm as same as synthetic indigo. Dyeing was done by reduction method with sodium hydrosulfite and sodium hydroxide. Leaf powder colorants produced blue color on silk fabrics, showing similar color to the one dyed traditionally with fresh juice extract. The powder colorants prepared at room temperature drying were more stable for long term storage than that prepared by hot air drying. Thus, the powder colorants prepared by room temperature drying was reduced and dyed in one-step process without sodium hydroxide in the dyebath for further investigate dyeing properties. K/S value of the fabric dyed without sodium hydroxide was much higher than one dyed with sodium hydroxide. Regardless of the addition of sodium hydroxide, rubbing fastness was fairly good showing above 4 rating. Fastness to dry cleaning and light of the fabrics dyed without sodium hydroxide were mote higher than that dyed in alkaline condition.

• Textile Coloration and Finishing
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• v.29 no.3
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• pp.171-179
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• 2017

This study was to investigate the practicality and functionality of water lily(Nymphaea tetragona) leaves as a natural dye resource while searching for various dyeing methods to utilize them. Effect of dyeing condition including methanol ratio of dyebath, dyeing temperature and time, mordanting method, etc were investigated. Colorants were prepared by extraction in methanol and followed drying process. When composing 30% of methanol in the dyebath, better dyeuptake and uniform dyeing were resulted. Pre-mordanting method gave better results in terms of dye uptake than post-mordanting method on the wool fabrics. Fe and Ti were effective for increasing the dye uptake on the silk fabrics. Depending on mordant type and mordanting method, the dyed fabrics got various color showing green, khaki, brownish yellow, dark brown, dark gray and so on. As for color fastness, the silk fabrics dyed with water lily extract showed relatively high rating in light fastness(3~4, 4~5 rating), washing fastness(4~5, 5 rating), and rubbing fastness(4, 4~5 rating). The silk and wool fabrics dyed with water lily leaves extract showed excellent antimicrobial activity over 98% of bacterial reduction rate against Staphylococcus aureus and Klebsiella pneumoniae. It was confirmed that water lily leaves can be used as a natural dye resource for dyeing wool and silk fabrics because its colorants showed excellent affinity and antimicrobial functionality as well as good colorfastness.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.5
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• pp.1-7
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• 2008

A study of new materials that are light-weight, high in strength has become vital to the machinery of auto industries. But then, there are a lot of problems with developing such materials that require expensive tools, and a great deal of time and effort. Therefore, the improvement of fatigue strength and fatigue life are mainly focused on by adopting residual stress. And Influence of corrosive condition for corrosion fatigue crack was investigated, after immersing in 3.5%NaCl, $10%HNO_3$+3.5%HF, $6%FeCl_3$. The immersion period was performed for 365days. The compressive residual stress was imposed on the surface according to each shot velocity based on shot peening, which is the method of improving fatigue life and strength. Fatigue life shows more improvement in the shot peened material than in the un peened material in corrosion conditions. The threshold stress intensity factor range was decreased in corrosion environments over ambient. Compressive residual stress of surface on the Shot-peen processed operate resistance force of fatigue crack propagation. The fatigue crack growth rate of the Shot-peened material was lower than that of the un peened material. Also m, fatigue crack growth exponent and number of cycle of the shot peened material was higher than that of the un peened material. That is concluded from effect of da/dN.