• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2003.05a
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• pp.147-152
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• 2003

원자로 압력용기 저합금강들은 원자로 가동 중 중성자 조사에 의해 재질열화 (material degradation)가 발생한다. 그러므로 계속적인 재질열화의 평가는 발전소의 수명을 예측, 평가하기 위해서 매우 중요하다. 그러나 표준시편을 이용한 인장시험, 충격시험 및 파괴인성 시험법 등은 조사시편의 크기 및 수량에 제한이 따르고, 높은 방사능으로 인해 시험편의 취급에도 제약을 받게 된다. 따라서 소형시편을 이용한 재료의 손상평가기술의 필요성이 부각되었고, 소형펀치시험(small punch test, SP test)은 그 중 하나의 유용한 시험 방법이다.(중략)

• Korean Journal of Materials Research
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• v.6 no.3
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• pp.253-263
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• 1996

고온.고압하에서 장시간 사용되는 고온부재용 구조물은 경년열화현상을 나타낸다 그러므로 구조물의 안정성 측면에서 재질열화의 정도를 정량적으로 평가하는 것이 중요하다. 그러나 실기 구조물에서 채취할 시험편의 크기와 수는 제한이 되기 때문에 새로운 비파괴적인 평가법이 요구되고 있다. 따라서 본 연구에서는 화력발전설비에 이용되는 탄소강과 페라이트강에 대한 열화도의 평가를 위해 입계부식법의 적용 가능성을 조사한다. 시험결과, 재질열화의 정도는 사용시간보다 사용온도에 더 큰 영향을 받았으며, Larson-Miller인자와 열화도([$\Delta$DBTT]SP)사이의 관계는 선형적이었으나, 강종에 따라 다른 기울기를 보였다. 반면, 연성-취성천이온도 ([$\Delta$DBTT]SP)와 격자절단비(Ni/No)와 관계는 강종에 무관하게 선형적인 비례관계를 나타내었다. 또한, [$\Delta$DBTT]SP와 Ni/No 의 관계로부터 입계부식법은 페라이트계 강뿐만아니라 탄소강에 대해서도 유용한 재질열화 평가 방법임을 알 수 있었다.

• Korean Journal of Microbiology
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• v.35 no.2
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• pp.169-172
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• 1999

Small-seeded legumes can be cultured enclosed in slant agar tubes if dlese plants are to he used for authenicaiing rhizobia or for enumerating 1-hizobia by the plant-inlection technique. An improved method has been developed with substiluting agar slant lor Korean paper(Har7ji). This method was panicularly useful for legumes with rigid radicle such as Cn.xsin 1mnmame. With this method Bmr!,~li1rzobin,17 sp. stram CN9135 on C nonmne induced root nodules biginning at day 7 of the nodulation period in 6% of the l ~ l a ~ l s , and all of ihe plants nodulated 14 days after inoculation by strain CN9135.

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.574-581
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• 2001

The microbial properties and acid tolerance of the three kinds of Acetobacter sp. isolated from persimmon vinegar were investigated. Acid tolerance was also evaluated. Acetobacter sp. were gram negative, short rod, nonspore forming and motile. They reacted positively catalase, methyl red, oxidation fermentation, Voges-Proskauer and nitrate reduction tests and negative to hydrogen sulfide test and ONPG. Acetobacter sp. showed normal growth curve in Carr broth and there was no significant difference between isolates and (standard on) typical strains such as Acetobacter aceti (KCTC1010), Acetobacter liquefaciens (KCTC2804), Acetobacter diazotrophicus (KCTC 2859). Optimum temperature and initial ethanol concentration in incubation were $30^{\circ}C$ and 6%, respectively. Growth and acid production of Acetobacter sp. were suppressed by the concentration of above 4% acetic acid. The amount of $Mg^{++}$ release from Acetobacter sp. cells in medium was increased by acetic acid, and almost in the concentration of 6% acetic acid. Glycolysis by Acetobacter sp. had optimal pH about 6.0 to 7.0 and more stable in acidic condition than in alkalic. The $H^+-ATPase$ of Acetobacter sp. S-1 and S-3 showed a maximal activity between pH values of approximately 5.5 to 7.5 and 6.0 to 7.5, respectively.

• Korean Journal of Poultry Science
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• v.38 no.3
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• pp.165-171
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• 2011

This study was conducted to investigate the effects of dietary supplementation of copper-soy proteinate (Cu-SP) on the performance of laying hens. A total of 1,000 Hy-Line Brown laying hens of 32 wks old were assigned to one of the following 5 dietary treatments: Control, Cu-SP 50, 100, 150, 200 (50, 100, 150, 200 ppm Cu supplementation as Cu-soy proteinate). Each treatment was replicated 4 times with fifty birds per replication, housed in 2 birds cages. Fifty birds units were arranged according to randomized block design. Feeding trial lasted 5 wks under 16L : 8D lighting regimen. There were no significant differences among treatments in hen-day and hen-house egg production, egg weight, broken & soft egg production. Feed intake and feed conversion rate (FCR) were significantly (P<0.01) lower in Cu-SP treated groups than Control. Eggshell thickness was significantly (P<0.01) higher in Control than Cu-SP 100, 150 and 200. Egg yolk color index was significantly (P<0.01) higher in Cu-SP 200 than other treatments. Egg shell color index was significantly (P<0.05) higher in Cu-SP 150 and Cu-SP 200 than Cu-SP 100. Concentration of copper, iron and zinc of the egg yolk were not significantly influenced by treatment. There were no significant differences in the level of leukocytes and erythrocytes in the chicken blood. The result of this experiment showed that dietary supplementation of Cu-SP at the level of 50ppm of Cu can reduce feed intake and FCR.

• The Korean Journal of Pesticide Science
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• v.17 no.3
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• pp.193-199
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• 2013

Burkholderia pyrrocinia CAB08106-4 has an anti-bacterial effect on Garlic White Rot caused by Sclereotium cepivorum and Sclereotium sp.. It is an environmentally friendly microbial product that prevents and controls a variety of phytopathogens involving Garlic White Rot caused by Sclereotium cepivorum and Sclereotium sp.. The aim of this study was to assess and to compare the pathogenicity of Burkholderia pyrrocinia CAB08106-4 by single exposure of rats through several routes such as oral, intranasal and intravenous. For the acute toxicity / pathogenicity study, the animals were sacrificed on days 3, 7, 14 and 21, and macroscopically observed their organs to examine the numbers of internally-retained pesticidal microbes. Clinical examinations were performed daily during administration period, and body weight gain was evaluated. In the study, no clinical sign, weight gain and mortality were observed in relation to the administration of test article. The significant changes of internal/external microbes by test article were not detected. The pathological findings in relation to the administration of the test article in the necropsy were not observed. It could be concluded that the microorganism was not toxic or pathogenic in rats via oral, intranasal and intravenous route.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.8
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• pp.2033-2042
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• 1993

In conventional SCC susceptibility test, there are constant strain test, constant load test, slow strain rate test(SSRT) and K$_{ISCC}$ test. Among them, the SSRT method is much more aggressive in producing SCC than the other tests, so that the test time of it is considerably reduced. But this SSRT method has mostly been worked using the uniaxial tensile specimen untill now. Therefore, the SSRT method using the tensile specimen(Ten-SSRT) has much difficulty in SCC susceptibility evaluation of a localized region like weldment and the advantage material of high order. Recentely, the small punch(SP) test method using miniaturized small specimen is the very effective test method for fracture strength evaluation of a localized region like weldment and fusion reactor wall irradiated in the nuclear power plant. This paper investigated the possibility of SCC susceptibility evaluation by the SP-SSRT method using the miniaturized small specimen. Therefore, we obtained the result that the SP-SSRT had the possibility for the evaluations of SCC susceptibility for shorter time to corrosive environment compare to Ten-SSRT which was conventional method.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.9 s.252
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• pp.1034-1040
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• 2006

Due to the need of increasing thermal efficiency, supercritical pressure and temperature have been utilized in power plants. It is well known that 9Cr1Mo steel is suitable fer use in power plants operating at supercritical conditions. Therefore, to ensure the safety and the soundness of the power plant, creep characterization of the steel is important. In this study, the creep characterization of the gCr1Mo steel using small punch creep(SP-Creep) test has been described. The applied load and the central displacement of the specimen in SP-Creep test have been converted to bearing stress and strain of uc, respectively. The converted SP-Creep curves clearly showed the typical three-stage behavior of creep. The steady-state creep rate and the rupture time of the steel logarithmically changed with the bearing stress and satisfied the Power law relationship. Furthermore, the Larson-Miller parameter of the SP-Creep test agreed with that of the tensile creep test. From the comparison with low Cr-Mo steels, the creep characteristics of 9Cr1Mo steel proved to be superior. Thus, it can be confirmed that the 9Cr1Mo steel is suitable for supercritical power plant.

• Magazine of korean Tunnelling and Underground Space Association
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• v.22 no.2
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• pp.46-54
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• 2020

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.9
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• pp.834-843
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• 2016

In this paper, the design of a PIN diode S-band transfer-type SP4T including its driver circuit is presented. Each path of the SP4T is composed of the cascade connection of series-shunt PIN diodes to improve the isolation performance. The SP4T is implemented using chip type PIN diodes and a 20 mil AIN substrate fabricated using thin film technology. The driver circuit for the SP4T is designed using a multiplexer and four NMOS-PMOS push-pull pair. From on-wafer measurement, the fabriacted SP4T shows a maximum insertion loss of 1.1 dB and a minimum isolation of 41 dB. The time performance of the driver circuit is evaluated using the packaged PIN diodes with the identical PIN diode chip, and the transition time for on-off and off-on are below 100 nsec. For an input power level of 150 W, the measured insertion loss and isolation are close to those of the on-wafer measurement taking into consideration of the coaxial package mismatch and insertion loss.