• Korean Journal of Breeding Science
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• v.50 no.4
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• pp.534-539
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• 2018

'Hwawang' is an early maturing and short statured rice cultivar adaptable to the rice-cash crop rotation system that was developed by the rice breeding team of the Department of Southern Crop, National Institute of Crop Science (NICS), Rural Development Administration (RDA), Korea, in 2012. This cultivar was derived from the cross of YR25867 (Hitomebore//YR21247-B-B-B-49-1/Sasanishiki BL4) and YR25866 (Akidagomachi//YR21247-B-B-B-49-1/Sasanishiki BL4) during the 2005/2006 winter season and was fixed as a homozygous line by a doubled haploid breeding system. In the replicated yield trial in 2009, a promising line (YR26253Acp26-1) showed a good phenotype and high yield potential, and so it was selected and designated as 'Milyang256'. The local adaptability test of 'Milyang256' was carried out at three locations from 2010 to 2012. It was named 'Hwawang' and had a high head rice ratio and good eating quality. The culm length of 'Hwawang' averaged 62 cm during the yield trials and was 10 cm shorter than that of 'Keumo'. The number of spikelets per panicle of 'Hwawang' was significantly lower than that of 'Keumo', but the number of tillers per hill was higher. This variety showed resistance to bacterial blight disease but was moderately susceptible to both leaf and neck blast. The milled rice yield of 'Hwawang' was 452 kg/10 a at the late transplanting stage of the local adaptability test. Thus, 'Hwawang' is well adapted to the rice-cash crop rotation system in the southern plain area. (Registration No. 5106)

• Journal of Radiation Protection and Research
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• v.24 no.2
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• pp.73-86
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• 1999

The ion-exchange method for the purification of primary coolant has been used broadly in PWR(pressurized water reactor)-type nuclear power plants due to its high decontamination efficiency, simple system, and easy operation. However, its non-selective removal of metal and non-radionuclides shortens its life, resulting in the generation of a large amount of waste ion-exchange resin. In this study, the feasibility of electrodeionization (EDI) was investigated for the purification of primary cooling water using synthetic solutions under various experimental conditions as an alternative method for the ion exchange. The results shows that as the feed flow-rate increased, the removal efficiency increased and the power consumption decreased. The removal rate was observed as a 1000 decontamination factor(DF) at a nearly constant level. For the synthetic solution of 3 ppm TDS (Total Dissolved Solid), the power consumption was 40.3 mWh/L at 2.0 L/min of feed flow rate. The higher removal rate of metal species and lower power consumption were obtained with greater resin volume per diluting compartment. However, the flow rate of the EDI process decreased with the elapsed time because of the hydrodynamic resistivity of resin itself and resin fouling by suspended solids. Thus, the ion-exchange resin was replaced by an ion-conducting spacer in order to overcome the drawback. The system equipped with the ion-conducting spacer resolved the problem of the decreasing flow rate but showed a lower efficiency in terms of the power consumption, the removal rate of metal species and current efficiency. In the repeated batch operation, it was found that the removal efficiency of metal species was stably maintained at DF 1000.

• Transactions of the KSME C: Technology and Education
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• v.4 no.2
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• pp.101-109
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• 2016

The material properties of heat resistant materials at power plants are affected by thermal aging as operating time is accumulated. In this study, the influence of thermal aging on yield strength, tensile strength and fracture behavior for Mod.9Cr-1Mo (ASME Grade 91) steel which is a material widely adopted for Generation IV nuclear energy system has been investigated and analyzed. Service exposed Gr.91 steel materials sampled from a piping system of an ultra-supercritical (USC) plant in Korea with accumulated operation time of 73,716 hours were used for material testing. The test results of the service exposed material specimens were compared with those of the virgin Gr.91 steel specimens. Those test data were compared with the material properties of ASME code and RCC-MRx code. Conservatisms of the material properties in the design codes have been quantified based on the comparisons of those from virgin and service exposed material specimens.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1614-1616
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• 2011

지중송전라인에서 전압등급의 상승은 선로손실을 줄이면서 밀집된 전력수요에 대응하거나 특별히 고전압 수요를 맞추기 위한 것으로 이것은 XLPE Cable의 제조기술이 향상되면서 지속적으로 진행되어온 초고압송전계통의 일반적 추세이다. 이러한 경향으로 해외에서는 케이블 도체의 송전용량을 증대시킬 수 있는 방법으로 케이블 도체에 에나멜 코팅을 하여 집합을 한다. 그러므로써 기존 케이블에서 발생되는 표피현상 및 근접효과에 의한 AC 저항 요소를 줄여 요구하는 전류용량을 기존 비소선절연 케이블에 비해 더 많이 송전할 수 있다. 하지만, 소선절연 케이블이 전류 용량을 증대 시킬 수 있는 장점은 있으나 접속재의 경우 도체의 에나멜 코팅을 제거해야 하는 문제점이 있다. 당사는 에나멜 코팅을 제거하는 방법을 개발 완료함으로써 본 접속재의 개발을 앞당길 수 있었다. 당사는 쿠웨이트 400kV MEW/C/3931 Project에 400kV XLPE 1C${\times}$2500SQ 소선절연 초고압송전라인을 적용하였는데 본고에서는 여기에 적용된 400kV XLPE 1C${\times}$25000SQ 소전절연 케이블 부속재의 신뢰성을 높이기 위한 설계방법, 시험 및 시공에 대하여 요약하였다.

• Horticultural Science & Technology
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• v.18 no.5
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• pp.594-598
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• 2000

This study was carried out to investigate the tissue-specific expression of ${\beta}$-glucuronidase (gus) gene driven by endosperm-specific promoter (Z4 promoter) in the transgenic tobacco and to find out inheritance pattern of transgene to the next generation. Tobacco (Nicotiana tabaccum cv. Havana SR1) was transformed with Agrobacterium tumerfaciens LBA4404 harboring BV3 construct containing gus gene driven by Z4 promoter and a kanamycin resistant gene. Seven hundred bp PCR products, indicating the presence of npt II gene, were found in the all eight transformants by PCR analysis using nptII primers. To study the expression pattern of the two different kind of promoters, leaf disks of the Z4pro-gus-transformed plants and 35Spro-gus-transformed plants were analyzed histochemically for gus activity. As a result, leaf disks of Z4pro-gus-transformed plants showed very weak and partial positive gus activity. In contrast, leaf disks of 35Spro-gus-transformed plants showed relatively strong positive gus activity. To investigate the expressed position of Z4 promoter, seeds from Z4pro-gus-transformed plants and 35Spro-gus-transformed plants were analyzed histochemically for gus activity. Z4pro-gus-transformed seeds showed positive gus activity restricted to the endosperm. However, the blue-colored product in 35Spro-gus-transformed seeds was observed in all the area including endosperm. Kanamycin resistance assay showed that transgenes were stably inherited to next generation in all lines.

• Journal of Plant Biotechnology
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• v.42 no.4
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• pp.284-289
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• 2015

Powdery mildew (Podosphaera xanthii) commonly occurs in cultivated fields of melon (Cucumis melo L.). It inflicts a lot of damages. Therefore, breeding resistant lines is essential. Development of a resistant line by integrating resistance gene takes a long time. In addition, break down of developed resistance by generating new virulent fungus strains increases disease susceptibility. This phenomenon was related to races of powdery mildew. Therefore, it is important to develop a DNA marker to genetically analyze race-specific resistance genes of melon powdery mildew to breed resistant lines. To date, a total of 28 races of Podosphaera xanthii have been reported in the literature. In Japan, 10 races have been reported in the Ibaraki region. We developed a system to characterize the races of Podosphaera xanthii and confirmed eight out of those 10 races in the Ibaraki region. In Korea, only one race has been characterized to date. However, some different races were detected. Through genetic analysis of resistant lines and susceptible lines of powdery mildew, resistance genes of race1 (Pm-X, PXB, and Pm-R 1), race N1 (PXA), race 2 (Pm-w and Pm-R 2), race 3 (Pm-X3), and race 5 (Pm-X5 and Pm-R5) were identified in melon. These related genes of race 1, 3, N1, 5, and race 1, 2, 5 were located at linkage group II and V, respectively. In race 1, resistance gene was located in the linkage group XII. In addition, each race-specific marker related to specific resistance gene was developed. Using race information and race selection system obtained in this study, resistant line can be bred to develop resistant cultivar for several areas. Furthermore, this will make it more easily and economically to breed resistant lines by using selected markers.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.4
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• pp.405-413
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• 2015

In the US, the number of cases of subterranean water contamination from tritium leaking through a damaged buried nuclear power plant pipe continues to increase, and the degradation of the buried metal piping is emerging as a major issue. A pipe blocked from corrosion and/or degradation can lead to loss of cooling capacity in safety-related piping resulting in critical issues related to the safety and integrity of nuclear power plant operation. The ASME Boiler and Pressure Vessel Codes Committee (BPVC) has recently approved Code Case N-755 that describes the requirements for the use of polyethylene (PE) pipe for the construction of Section III, Division 1 Class 3 buried piping systems for service water applications in nuclear power plants. This paper contains tensile and slow crack growth (SCG) test results for high-density polyethylene (HDPE) pipe welds under the environmental conditions of a nuclear power plant. Based on these tests, the fracture surface of the PENT specimen was analyzed, and the fracture mechanisms of each fracture area were determined. Finally, by using 3D finite element analysis, limit loads of HDPE related to premature failure were verified.

• The Korean Journal of Pesticide Science
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• v.10 no.2
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• pp.131-137
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• 2006

This experiment was conducted to select prominent microorganisms with a good insecticidal activity among the ten species, which isolated from soil at the near of Chung-buk, Chung-nam, and Gang-won provinces and made protein crystal endotoxin. As a result, GB-413 strain was finally selected, which showed the high insecticidal activity against susceptible diamondback moth (Plutella xylostella), beet army worm (Spodoptera exigua) and tobacco cutworm (Spodoptera litura) as well as resistant diamondback moth strains. By modifying the cultivation process f.g. lowing the glucose concentration at early cultivation stage and adding the carbon after inducing the spores, the percentage of making spore as well as the number of active spore were increased and the time for cultivation and spore forming was reduced without a reduction of insecticidal activity. These results were not only applied successfully for the optimized cultivation process for a fermentation tank containing five tons capacity, but also improved the possibility of mass cultivation for commercial production.

• Journal of Plant Biotechnology
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• v.36 no.1
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• pp.75-80
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• 2009

In order to develop transgenic sweetpotato plants [Ipomoea batatas (L.) Lam. cv. Yulmi] with enhanced tolerance to oxidative stress, we constructed transformation vectors expressing 2-Cys peroxiredoxin (Prx) gene under the control of the stress-inducible SWPA2 or enhanced 35S promoter (named as SP or EP). Transgenic sweetpotato plants were attempted to generate from embryogenic calli using an Agrobacterium-mediated transformation system. Embryogenic calli gave rise to somatic embryos and then converted into plantlets on MS medium containing 100 mg/L kanamycin. Transgenic plants were regenerated in the same medium. Southern blot analysis confirmed that the Prx gene was inserted into the genome of the plants. To further study we selected the transgenic plant lines with enhanced tolerance against methyl viologen (MV). When sweetpotato leaf discs were subjected to methyl MV at $20{\mu}M$, transgenic plants showed about 40% higher tolerance than non-transgenic or empty vector-transformed plants.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.538-543
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• 2018

Powdery mildew caused by Podosphaera xanthii is a disease in cucurbit crops especially in green house. The objective of this study was to determine the effect of alternative fungicide spraying system for control of powdery mildew disease. We selected four fungicides with different mode of action and made three treatment combinations of each fungicide in 2017. Pyraclostrobin-flutianyl-penthiopyrad treatment showed the highest control value (87%) while, pyraclostrobin-pyraclostrobin-pyraclostrobin treatment showed the lowest control value (32.5%). So it seemed like the treatment was not suitable for control of powdery mildew. In 2018, pyraclostrobin of pyraclostrobin-flutianyl-penthiopyrad was replaced to contact fungicide called iminoctadine-tris-albesilate and compared control effect of two treatments. Two of the treatments showed similar control value (87.0% for pyraclostrobin, 89.0% for iminoctadine-tris-albesilate). These two tests in 2017 and 2018 indicated that alternative treatment of different fungicides is essential for controlling of powdery mildew and inhibiting development of fungicide resistance.