• Nuclear Engineering and Technology
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• v.49 no.7
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• pp.1563-1570
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• 2017

In order to perform dry interim storage and transportation of the spent-fuel assemblies of the Bushehr Nuclear Power Plant, dual-purpose casks can be utilized. The effectiveness of different neutron-shield materials for the dual-purpose cask was analyzed through a set of calculations carried out using the Monte Carlo N-Particle (MCNP) code. The dose rate for the dual-purpose cask utilizing the recently developed materials of $epoxy/clay/B_4C$ and $epoxy/clay/B_4C/carbon$ fiber was less than the allowable radiation level of 2 mSv/h at any point and 0.1 mSv/h at 2 m from the external surface of the cask. By utilization of $epoxy/clay/B_4C$ instead of an ethylene glycol/water mixture, the dose rates on the side surface of the cask due to neutron sources and consequent secondary gamma rays will be reduced by 17.5% and 10%, respectively. The overall dose rate in this case will be reduced by 11%.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.96.2-97
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• 2003

More than 1200 microorganisms were isolated from soil samples collected from various sources and localities. Among the isolates, 2 actinomyces (TH-04 and BA313) and 1 Bacillus sp. (CJ3) were selected as antagonists to pepper anthracnose fungus Colletotrichum gloeosporioides. These 3 isolates inhibitied mycelial growth of C gloeosporioides and the inhibition rates were over 70％ on PDA. When the isolates were co-cultured with conidia of C. gloeosporioides in potato dextrose broth, conidial germination was severely inhibited and the inhibition rates of TH-04, BA313, and CJ3 at 24 hours were 75％, 72％, and 68％, respectively. The inhibition rates at n hours incubation were not much different from the rates at 24 hours. To check the activity on the plant, each isolate was mixed with equal volume of conidial suspension of C. gloeosporioides and wound-inoculated on green pepper fruit. After 6 days, the anthracnose lesions on the fruits inoculated with the mixture were much smaller than the lesions caused by the C. gloeosporioides itself. The lesion areas of TH-04 or BA313 treated pepper were less than 30％ of the check. TH-04 and BA313 also showed antagonistic activity to Phytophthora spp. and Botrytis cinerea. By scanning electron microscopy and fatty acid analyses (MIDI), TH-04 and BA313 were identified to Streptomyces halstedii and S. violaceusniger, repectively.

• Journal of the Korean Society of Combustion
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• v.18 no.4
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• pp.1-11
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• 2013

The oxy-fuel combustion is $CO_2$ capture technology that uses mixture of pure $O_2$ and recirculated exhaust as oxidizer. Currently some Oxy-fuel power plants demonstration project is underway in worldwide. Meanwhile research project for converting 125 MWe Young-Dong power plant to 100 MWe oxy-fuel power plants is progress. In this paper, 1 D process analytical approach was applied for conducting process design and operating parameters sensitivity analysis for oxy-fuel combustion of Young-Dong power plant. As a result, appropriate gas recirculation rates was 74.3% that in order to maintain normal rating superheater, reheater steam temperature and boiler heat transfer patterns. And boiler efficiency 85.0%, CPU inlet $CO_2$ mole concentration 71.34% was predicted for retrofitted boiler. The oxygen concentration in the secondary recycle gas is predicted as 27.1%. Meanwhile the oxygen concentration 22.4% and moisture concentration 5.3% predicted for primary recycle gas. As the primary and secondary gas recirculation increases, then heat absorption of the reheater is tends to increases whereas superheater side is decreased, and also the efficiency is tends to decrease, according to results of sensitivity analysis for operating parameters. In addition, the ambient air ingression have a tendency to lead to decline of efficiency for boiler as well as decline of $CO_2$ purity of CPU inlet.

• Journal of Plant Biology
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• v.11 no.3
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• pp.1-7
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• 1968

Organic matter in rice-paddy soils exercises two antagonistic effects on the rice plant under water-logged conditions in growing season in the course of its decomposition: It liberates mineral nutrients and promotes soil fertility. On the other hand, however, it demands oxygen for its decay and therefore competes with rice roots for this element, when applied in large quantity of fresh status. For the practical end of rice culture, it is most desirable that these two effects should not contend with each other. To determine the proper content of organic materials to be applied, the influences of varied amounts of a homogeneous mixture of dried green manure, ranging from 0 to 20g/pot (1/20,000 tanbo), upon hte growth of rice was investigated in a sand culture. Labeled phosphorus fertilizer was also used in the form of KH232PO4 to evaluate the availability of this nutrient in the soil. Under the present experimental conditions, green mature seems to have influenced little on the growth of rice, except on number of grains produced and grains/straw ratio. Moreover, no sympton of growth inhibition is obsrvable even by the largest amount of its application. The available phosphorus, as estimated by A-value, appears to have increased, as the amount of organic materials applied increases. In view of the fact that pure sand instead of a paddy soil is used in this culture, the present results would not be directly applicable to practical rice farming. Besides, the estimated A-value is in need of further study, since it varies according to method of application, as suggested by Nishigki et. al. (1958).

• Korean journal of applied entomology
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• v.58 no.4
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• pp.281-282
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• 2019

We have developed a composition containing three kinds of plant extracts (Deris, Citronella, and Cinnamon) and supplements (xanthan gum and silicone-based compounds) having high control effects on Metcalfa pruinosa. This composition had more than 90% of the nymph bug control effect in the ginseng plantation. In addition, since the insecticidal rate is high for other absorptive pests, it is considered that it can be used as a countermeasure against the implementation of the PLS (positive list system).

• Journal of Plant Biotechnology
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• v.30 no.2
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• pp.167-172
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• 2003

Immature zygotic embryos of Eleutherococcus senticosus seeds matured rapidly within one month when the seeds comprising zygotic embryos were pieced to small size and cultured on 1/2 MS medium. Frequency of somatic embryos formation was declined rapidly when the zygotic embryos germinated and grew to plantlets. Embryogenic cells were induced by consecutive subculture of somatic embryos on MS medium with 1.0mg/L2,4-D. After heart-shaped somatic embryos were induced by suspension culture, these embryos were plated onto petri dish to support maturation of embryos. Germination of embryos occurred on medium with 5mg/L GA$_3$and transferred to culture bowl to stimulate the further growth. Frequency of soil survival of plantlets was influenced by soil mixture (perlite and peatmoss). The suitable combination of perlite and peatmoss was 1:5, and the soil survival rate was 78% after 4 months. The soil transferred plantlets were over-wintered in field condition after defoliation. New year sprouting of plants was achieved successfully and they grew to adult plants. These results indicate that the systematic procecure of plant production in E. senticosus for micro propagation.

• Journal of Plant Biotechnology
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• v.36 no.2
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• pp.97-105
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• 2009

Seed storage lipids of plants, essential for seed germination as energy supplier, have been used for humankind and animal as nutrition sources. Fatty acids of vegetable oils have the characters appropriate for industry based on their chain length, the position and the number of double bonds. So they are used as raw materials for lubricants, cosmetics, soaps, paints and plastics or as energy source such as bio-diesel. However, there is a limit that applies vegetable oils from typical oil crops for industrial uses, mainly because of the mixture of five common fatty acids. Therefore, identification of unusual fatty acids for industrial uses from diverse plant resources and metabolic engineering to produce unusual fatty acids have been carried out in Arabidopsis as a model for the study of oilseed biology. Here, we discuss the unusual fatty acids for industrial uses, the genes synthesizing them in lipid metabolism, and the current limits in production of transgenic plants accumulating unusual fatty acid in their seeds. In addition, we describe our work on metabolic engineering of Brassica napus for the production of the unusual fatty acid ricinoleic acid in the seed, because of its industrial uses.

• Journal of Plant Biotechnology
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• v.36 no.2
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• pp.170-173
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• 2009

Leaf and petiole explants of Pulsatilla koreana NAKAI were cultured on MS medium supplemented with various concentrations of zeatin, kinetin or BAP combined with 0.05 mg/L IAA. After 6 weeks of culture, effects of cytokinin on adventitious shoot formation from explants were investigated. The highest frequency of shoot formation was obtained when petiole explants were cultured on medium with 0.5 mg/L zeatin and 0.05 mg/L IAA. Regenerated shoot were transferred on to root induction medium. The best root formation was observed at 1/2 MS medium with 1.5 mg/L NAA. Rooted plantlets were transplanted to a mixture of perlit and soil (1:3), where they were successfully acclimatized.

• Korean Journal of Medicinal Crop Science
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• v.14 no.4
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• pp.225-228
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• 2006

To acquire the normal regeneration of plantlets, we investigated combinations and concentrations of plant growth regulations for optimal conditions of adventitious root formation. Based on the previous study, we performed callus and shoot induction. When induced shoot was transferred into a rooting medium containing plant hormones, it wilted and died. Thus, the shoot proliferated on 1/2 MS medium for 10 days and was then treated with MS medium supplemented with 3.0 mg/L NAA for 3 days. Adventitious root formations were observed after shoot planlets were transferred to 1/3 MS medium. The concentrations of salt and sucrose were gradually reduced in MS medium and the rooted plantlets were transferred for acclimatization into a mixture of peatmoos : perlite (3 : 2).

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.11 no.1
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• pp.1-11
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• 2015

Feedwater Heaters are important components in a nuclear power plant. As the age of heater increases, the maintenance cost required for continuous operation also increases. Most heaters have the carbon steel shells, tube support plates and flow baffles. The carbon steel is susceptible to flow-accelerated corrosion. This is especially true if the flow has a two-phase mixture of steam and condensate. The wall thinning around the wet steam entrance area of the shell is inevitable during some long term operation. The structural integrity of the feedwater heater shell affects the safe operation of the nuclear power plant. Therefore, it is needed for the thinned shell to be repaired. The maintenance method for preventing failure of the shell should be determined by investigating various factors including the stress distribution of thinned area. The stress analysis of the shell including the steam entrance region is studied in this paper. The results of thinned shell is compared with that of intact shell.