• Title/Summary/Keyword: Screening effect

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Probabilistic Fracture Mechanics Analysis of Reactor Vessel for Pressurized Thermal Shock - The Effect of Residual Stress and Fracture Toughness - (가압열충격에 대한 원자로 용기의 확률론적 파괴역학해석 - 잔류응력 및 파괴인성곡선의 영향 -)

  • Jung, Sung-Gyu;Jin, Tae-Eun;Jhung, Myung-Jo;Choi, Young-Hwan
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.6
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    • pp.987-996
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    • 2003
  • The structural integrity of the reactor vessel with the approaching end of life must be assured for pressurized thermal shock. The regulation specifies the screening criteria for this and requires that specific analysis be performed for the reactor vessel which is anticipated to exceed the screening criteria at the end of plant life. In case the screening criteria is exceeded by the deterministic analysis, probabilistic analysis must be performed to show that failure probability Is within the limit. In this study, probabilistic fracture mechanics analysis of the reactor vessel for pressurized thermal shock is performed and the effects of residual stress and master curve on the failure probability are investigated.

A Study on the Vibration Isolation by Line-drilling Holes (방진공에 의한 발파진동차단효과의 실험 및 수치해석적 연구)

  • 조상호;양형식
    • Tunnel and Underground Space
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    • v.10 no.3
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    • pp.481-485
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    • 2000
  • Vibration screening trench is very effective to reduce the ground vibration, but to construct the trench in the rock mass is not easy. Various line drilling methods have been tried to replace the trenching. In this study, UDEC was applied to simulate the screening effect of drilling holes in 2 dimensional ground model. Field measurement was conducted and compared to numerical analysis.

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A Study on the Vibration Isolation by Line-drilling Holes (방진공에 의한 발파진동차단효과의 실험 및 수치해석적 연구)

  • 조상호;양형식
    • Proceedings of the Korean Society for Rock Mechanics Conference
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    • 2000.09a
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    • pp.235-239
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    • 2000
  • Vibration screening trench is very effective to reduce the ground vibration, but to construct the trench in the rock mass is not easy. Various line drilling methods have been tried to replace the trenching. In this study, UDEC was applied to simulate the screening effect of drilling hopes in 2 dimensional ground model. Field measurement was conducted and compared to numerical analysis.

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Free Spanning of Offshore Pipelines by DNV 2002 (DNV 2002에 의한 해저관로의 자유경간해석)

  • Choi, Han-Suk;Joo, Joo-Kyung
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2002.10a
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    • pp.29-33
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    • 2002
  • A procedure of free span and fatigue analysis of offshore pipelines was made per DNV-RP-F105, 2002. The new method includes the axial force and deflection load in pipelines. The screening criteria were used to calculate the allowable span lengths. The screening criteria allow small amplitudes of vortex-induced vibration due to wave and current loading. However, the induced pipe stress is very small and usually below the limit stress of a typical S-N curve. A simplified method was established to calculate the fatigue damage due to long-term current distribution. The long-term current statistics was assumed with a 3-parameter Weibull distribution. The fatigue damage was estimated for the span lengths obtained from the screening criteria for various conditions. Sample calculations show the effect of axial force for various boundary conditions.

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Screening, Signalling and Wage Effect of English Scores in Korean Labor Market: Evidence from College Graduates (노동시장에서 영어점수의 선별·신호 및 임금효과: 대졸자를 중심으로)

  • Lee, Sangheon;Yang, Jun Seok
    • Journal of Labour Economics
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    • v.34 no.2
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    • pp.79-107
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    • 2011
  • This study investigates the status of English scores in the Korean labor market. We provide an empirical explanation of how English scores affect labor performances in Korea. Specifically, we focus on the effects of TOEIC scores on college graduates' job opportunity and wage premium. Our empirical tests for TOEIC scores are implemented in three dimensions: (1) Screening effects (2) Signaling effects (3) Wage effects. The results are as follows. First, we find the positive correlation between TOEIC scores and job opportunities, which implies that TOEIC scores play an important role in employee selection process. Second, our tests give the same results when it comes to job seeker's use of TOEIC scores as signaling instrument. That is, high TOEIC scores have positive signaling effects in the labor market. However, there also exists disadvantage effect of low TOEIC scores, in that job applicants with TOEIC scores below certain level are even more disadvantageous than those with no TOEIC scores. Finally, wage premium of TOEIC scores are found, even when other variables (e.g. GPA) are controlled or we use the instrumental variable estimate.

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Vapour Effect of Kresoxim-methyl on Powdery Mildew of Barley and Cucumber (보리와 오이 흰가루병에 대한 Kresoxim-methyl의 훈증 효과)

  • Kim, Heung-Tae;Jang, Kyung-Soo;Choi, Gyung-Ja;Cho, Kwang-Yun
    • The Korean Journal of Pesticide Science
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    • v.10 no.4
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    • pp.359-366
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    • 2006
  • The protective effect of kresoxim-methyl was investigated on 6 important plant diseases, and the vapour effect of it did on barley and cucumber powdery mildews, respectively. With 2.0 ${\mu}g\;mL^{-1}$ of kresoxim-methyl, its high activities against wheat leaf rust and barley powdery mildew were showed such as 92 and 100%, while activities were very low against rice sheath blight, tomato gray mold, and tomato late blight. In vapour phase control activity of kresoxim-methyl against barley powdery mildew was positively correlated with the applied concentrations, except for azoxystrobin and metominostrobin. With 200 ${\mu}g\;L^{-1}$, its control value was 71.9%. When 1000 ${\mu}g\;m^{-3}$ of kresoxim-methyl in vapour phase was applied on 4 plants of cucumber in a vinyl chamber, 51.1% of control value on kresoxim-methyl-treated cucumber was showed 7 days after the application.

Effect of Prochloraz on Electrolytic Leakage and Spore Germination of Puccinia recondita Causing Wheat Leaf Rust

  • Kim, Heung-Tae;Jang, Kyung-Soo;Park, Gyung-Ja;Lee, Sun-Woo;Cho, Kwang-Yun
    • The Plant Pathology Journal
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    • v.19 no.4
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    • pp.189-194
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    • 2003
  • The effects of prochloraz on membrane permeability and germination of uredospores of Puccinia recondita were investigated to determine its potential mode of action on wheat leaf rust control activity. Disease control activity of ergosterol biosynthesis inhibitors (EBIs) and their activities on uredospore membrane permeability and germination were examined with wheat leaf rust pathogen, both in vitro and in vivo. While wheat leaf rust was not controlled by prochloraz, electrolytic leakage and spore germination of P. recondita uredospore was the highest with the use of prochloraz among the eight fungicides tested. Prochloraz stimulated uredospore of P. recondita to germinate at a higher ratio. Although certain EBIs, such as hexaconazole, showed excellent control activity, their effects on uredospore membrane permeability and germination was much inferior to prochloraz. Therefore, results of this study suggest that effects of EBIs on membrane permeability and germination of uredospore are not always correlated with their disease control activity.

A Study of aticarcinogenic effects of dimethyl disulfide and diallyl disulfide in a rat multi-organ carcinogenesis model (다장기 발암모델을 이용한 dimethyl disulfide와 diallyl disulfide의 항발암효과)

  • Kang, Boo-Hyon;Son, Hwa-Young;Ha, Chang-Su;Rho, Jung-Koo
    • Korean Journal of Veterinary Pathology
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    • v.1 no.1
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    • pp.13-25
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    • 1997
  • The anticarcinogenic effects of dimethyl disulfide(DMDS, methyl disulfide)and diallyl disulfide(DADA, allyl disulfide) were studied in a 28 weeks rat multi-organ carcinogenesis model. neoplastic and preneoplastic lesions were observed in the liver kidney thyroid gland esophagus duodenum colon, rectum and adrenal gland. Tesults showed that neoplastic lesions in the kidney liver and thyroid gland were inhibited by DADS but those in the liver and colon were enhanced by DMDS when compared to positive control group. incidence of neoplastic lesions in the other organs were not changed by DMDS or DADS exposure. While GST-p positive foci in the liver were increased by DMDS, DADS had no effect. There was no significant histopathological lesion in DMDS or DADS treated group without pretreatment with carcinogens.

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Identification of a lead small-molecule inhibitor of anthrax lethal toxin by using fluorescence-based high-throughput screening

  • Wei, Dong;Bu, Zhaoyun;Yu, Ailian;Li, Feng
    • BMB Reports
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    • v.44 no.12
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    • pp.811-815
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    • 2011
  • Inhalational anthrax is caused by B. anthracis, a virulent sporeforming bacterium which secretes anthrax toxins consisting of protective antigen (PA), lethal factor (LF) and edema factor (EF). LF is a Zn-dependent metalloprotease and is the main determinant in the pathogenesis of anthrax. Here we report the identification of a lead small-molecule inhibitor of anthrax lethal factor by screening an available synthetic small-molecule inhibitor library using fluorescence-based high-throughput screening (HTS) approach. Seven small molecules were found to have inhibitory effect against LF activity, among which SM157 had the highest inhibitory activity. All theses small molecule inhibitors inhibited LF in a noncompetitive inhibition mode. SM157 and SM167 are from the same family, both having an identical group complex, which is predicted to insert into S1' pocket of LF. More potent small-molecule inhibitors could be developed by modifying SM157 based on this identical group complex.

Effect of an Integrated Breast Health Program for Pregnant Women on Knowledge, Attitude, and Early Screening Practice Related to Breast Cancer

  • Jun, Eun-Young
    • Journal of Korean Academic Society of Home Health Care Nursing
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    • v.28 no.2
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    • pp.186-196
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    • 2021
  • Purpose: Breast cancer is becoming increasingly prevalent among young Korean women. During pregnancy, women's concern regarding their breasts heightens. Thus, pregnancy provides a window of opportunity for breast cancer prevention and management along with antenatal care. This study developed and evaluated an integrated breast health program for pregnant women. Methods: This study employed a non-equivalent control group and non-synchronized design (22 experimental, 29 control). Women pregnant for over 28 weeks participated. The two-session integrated breast health program focused on breast management during breastfeeding and education about breast cancer prevention and early screening. Results: During the early postpartum period (within three months after the program), there were statistically significant differences in knowledge and attitude about breast cancer and breast self-examination before and after the program. There were also statistically significant differences in BSE at 6 and 12 months after the program and mammography at 12 months after the program. However, there were no statistically significant differences in clinical breast examination and breast ultrasonography at 6 and 12 months after the program. Conclusion: The integrated breast health management program was effective in increasing knowledge and improving attitudes regarding breast cancer, BSE, and early screening practices among pregnant women. Further studies should consider providing breast health programs differently for each phase of pregnancy and continuing the same after delivery.