• Title/Summary/Keyword: Combined safety approach

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Application of a combined safety approach for the evaluation of safety margin during a Loss of Condenser Vacuum event

  • Shin, Dong-Hun;Jeong, Hae-Yong;Park, Moon-Ghu;Sohn, Jung-Uk
    • Nuclear Engineering and Technology
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    • v.54 no.5
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    • pp.1698-1711
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    • 2022
  • A combined safety approach, which uses a best-estimate computer code and adopts conservative assumptions for safety systems availability, is developed and applied to the safety margin evaluation for the Loss of Condenser Vacuum (LOCV) of the 1000 MWe Korean Nuclear Power Plant. The Multi-dimensional Analysis of Reactor Safety-KINS standard (MARS-KS) code is selected as a best-estimate code and the PAPIRUS program is used to obtain different initial operational conditions through random sampling of control variables. During an LOCV event, fuel integrity is not threatened by the increase in Departure from Nuclear Boiling Ratio (DNBR). However, the high pressure in the primary coolant system and the secondary system might affect the system integrity. Thus, the peak pressure becomes a major safety concern. Transient analyses are performed for 124 cases of different initial conditions and the most conservative case, which results in the highest system pressure is selected. It is found the suggested methodology gives similar peak pressures when compared to those predicted from existing methodologies. The proposed approach is expected to minimize the time and efforts required to identify the conservative plant conditions in the existing conservative safety methodologies.

Combined Treatment with Low Concentrations of Aqueous and Gaseous Chlorine Dioxide Inactivates Escherichia coli O157:H7 and Salmonella Typhimurium Inoculated on Paprika

  • Kim, Hyun-Gyu;Song, Kyung Bin
    • Journal of Microbiology and Biotechnology
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    • v.27 no.3
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    • pp.492-499
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    • 2017
  • Combined treatment with gaseous and aqueous chlorine dioxide ($ClO_2$) was performed to improve the microbiological safety and quality of paprika. A single treatment of 50 ppmv $ClO_2$ gas for 30 min decreased the populations of Escherichia coli O157:H7 and Salmonella Typhimurium by 2.33 and 2.91 log CFU/g, respectively. In addition, a single treatment of aqueous $ClO_2$ (50 ppm) for 5 min decreased these populations by 1.86 and 1.37, respectively. The most dramatic effects were achieved by combined treatment of 50 ppm aqueous and gaseous $ClO_2$ for 30 min, which decreased populations of E. coli O157:H7 and S. Typhimurium by 4.11 and 3.61 log CFU/g, respectively. With regard to the qualities of paprika, no adverse effects were elicited by the combined treatment. Thus, combined treatment with aqueous and gaseous $ClO_2$ is a suitable approach that can be used to improve the microbial safety and quality of paprika.

A Study on the Adoption of SPICE in the Railway Software (철도분야 소프트웨어로의 SPICE 적용연구)

  • Joung, Eui-Jin;Shin, Kyung-Ho
    • Proceedings of the KIEE Conference
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    • 2006.04b
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    • pp.316-318
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    • 2006
  • It can be considered that the safety of software is combined with that of hardware, and also directly connected to system safety. Because the software in the railway system takes the form of Embedded that let it behave at the system level, instead of independent operation, the safety of the railway S/W is also important. The approach, for ensuring the quality and safety of those software, can be considered with two points of view. Those are views seeing from products, and from processes. The two points of approach are all necessary in the railway system. For the first of all, the process approach is to validate maturity of the organizations in accordance to the judging processes of organizations, which are specified by CMMI(Capability Maturity Model Integration) or SPICE(Software Process Improvement and Capability dEtermination: ISO/IECl5504). In this paper, as the first step of them, we are trying to find approaches to estimate the maturity of manufacturer and assessment organization in the railway system.

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Wind fragility analysis of RC chimney with temperature effects by dual response surface method

  • Datta, Gaurav;Sahoo, Avinandan;Bhattacharjya, Soumya
    • Wind and Structures
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    • v.31 no.1
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    • pp.59-73
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    • 2020
  • Wind fragility analysis (WFA) of concrete chimney is often executed disregarding temperature effects. But combined wind and temperature effect is the most critical limit state to define the safety of a chimney. Hence, in this study, WFA of a 70 m tall RC chimney for combined wind and temperature effects is explored. The wind force time-history is generated by spectral representation method. The safety of chimney is assessed considering limit states of stress failure in concrete and steel. A moving-least-squares method based dual response surface method (DRSM) procedure is proposed in WFA to alleviate huge computational time requirement by the conventional direct Monte Carlo simulation (MCS) approach. The DRSM captures the record-to-record variation of wind force time-histories and uncertainty in system parameters. The proposed DRSM approach yields fragility curves which are in close conformity with the most accurate direct MCS approach within substantially less computational time. In this regard, the error by the single-level RSM and least-squares method based DRSM can be easily noted. The WFA results indicate that over temperature difference of 150℃, the temperature stress is so pronounced that the probability of failure is very high even at 30 m/s wind speed. However, below 100℃, wind governs the design.

Safety of Brucea javanica and Cantharidin Combined with Chemotherapy for Treatment of NSCLC Patients

  • Ji, Zhu-Qing;Huang, Xin-En;Wu, Xue-Yan;Liu, Jin;Wang, Lin;Tang, Jin-Hai
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.20
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    • pp.8603-8605
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    • 2014
  • Objective: To assess the safety of Brucea javanica and Cantharidin combined with chemotherapy in treating patients with non-small-cell lung carcinoma. Method: A consecutive cohort of patients with NSCLC were divided into four groups: experimental group A treated with Brucea javanica injection combined with chemotherapy; experimental group B with Cantharidin injection combined with chemotherapy; experimental group C treated with Brucea javanica and Cantharidin injection combined with chemotherapy; and the control group receiving only chemotherapy. After more than two courses of treatment, safety, quality of life and side effects were evaluated. Results: The incidences of myelosuppression in groups A, B and C were lower than that in Control group (p<0.05), but without significant differences among A, B and C. Adverse effects on the gastrointestinal tract also were lower than in controls (p<0.05) without variation amnog the combined treatment groups. Conclusions: Brucea javanica or Cantharidin combined with chemotherapy could in both cases improve quality of life in our cohort of NSCLC patients without any increase in toxicity. However, further clinical experiments should be conducted to evaluate the efficacy of Brucea javanica and Cantharidin combined with chemotherapy for patients with NSCLC.

Noninvasive Rx of Breast Cancer by MR-guided High Intensity Focused Ultrasound

  • Moonen, Chrit
    • Proceedings of the KSMRM Conference
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    • 2005.09a
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    • pp.77-78
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    • 2005
  • A specific FUS-MRI platform was designed for breast cancer treatment. phased array technologies, sideways FUS transmission, and spatio-temporal temperature control in the complete region of interest, were combined for a novel therapy approach with enhanced safety and afficacy. A phase I clinical trial will start soon.

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New approaches to testing and evaluating the impact capability of coal seam with hard roof and/or floor in coal mines

  • Tan, Y.L.;Liu, X.S.;Shen, B.;Ning, J.G.;Gu, Q.H.
    • Geomechanics and Engineering
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    • v.14 no.4
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    • pp.367-376
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    • 2018
  • Samples composed of coal and rock show different mechanical properties of the pure coal or rock mass. For the same coal seam with different surrounding rocks, the frequency and intensity of rock burst can be significantly different in. First, a method of measuring the strain variation of coal in the coal-rock combined sample was proposed. Second, laboratory tests have been conducted to investigate the influences of rock lithologies, combined forms and coal-rock height ratios on the deformation and failure characteristics of the coal section using this method. Third, a new bursting liability index named combined coal-rock impact energy speed index (CRIES) was proposed. This index considers not only the time effect of energy, but also the influence of surrounding rocks. At last, a new approach considering the influences of roof and/or floor was proposed to evaluate the impact capability of coal seam. Results show that the strength and elastic modulus of coal section increase significantly with the coal-rock height ratio decreasing. In addition, the values of bursting liability indexes of the same coal seam vary greatly when using the new approach. This study not only provides a new approach to measuring the strain of the coal section in coal-rock combined sample, but also improves the evaluation system for evaluating the impact capability of coal.

Combined Non-Thermal Microbial Inactivation Techniques to Enhance the Effectiveness of Starter Cultures for Kimchi Fermentation

  • Su-Ji Kim;Sanghyun Ha;Yun-Mi Dang;Ji Yoon Chang;So Yeong Mun;Ji-Hyoung Ha
    • Journal of Microbiology and Biotechnology
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    • v.34 no.3
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    • pp.622-633
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    • 2024
  • For quality standardization, the application of functional lactic acid bacteria (LAB) as starter cultures for food fermentation is a well-known method in the fermented food industry. This study assessed the effect of adding a non-thermally microbial inactivated starter culture to kimchi, a traditional Korean food, in standardizing its quality. In this study, pretreatment based on sterilization processes, namely, slightly acidic electrolyzed water (SAEW) disinfection and ultraviolet C light-emitting diode (UVC-LED) of raw and subsidiary kimchi materials were used to reduce the initial microorganisms in them, thereby increasing the efficiency and value of the kimchi LAB starter during fermentation. Pretreatment sterilization effectively suppressed microorganisms that threatened the sanitary value and quality of kimchi. In addition, pretreatment based on sterilization effectively reduced the number of initial microbial colonies in kimchi, creating an environment in which kimchi LAB starters could settle or dominate, compared to non-sterilized kimchi. These differences in the initial microbial composition following the sterilization process and the addition of kimchi LAB starters led to differences in the metabolites that positively affect the taste and flavor of kimchi. The combined processing technology used in our study, that is, pre-sterilization and LAB addition, may be a powerful approach for kimchi quality standardization.

Behaviour and design of composite beams subjected to flexure and axial load

  • Kirkland, Brendan;Uy, Brian
    • Steel and Composite Structures
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    • v.19 no.3
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    • pp.615-633
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    • 2015
  • Composite steel-concrete beams are used frequently in situations where axial forces are introduced. Some examples include the use in cable-stayed bridges or inclined members in stadia and bridge approach spans. In these situations, the beam may be subjected to any combination of flexure and axial load. However, modern steel and composite construction codes currently do not address the effects of these combined actions. This study presents an analysis of composite beams subjected to combined loadings. An analytical model is developed based on a cross-sectional analysis method using a strategy of successive iterations. Results derived from the model show an excellent agreement with existing experimental results. A parametric study is conducted to investigate the effect of axial load on the flexural strength of composite beams. The parametric study is then extended to a number of section sizes and employs various degrees of shear connection. Design models are proposed for estimating the flexural strength of an axially loaded member with full and partial shear connection.

Reliability-Based Optimization of Continuous Steel Box Girder Bridges (신뢰성에 기초한 강상형 연속교의 단면 최적설계)

  • 조효남;이두화;정지승;민대홍
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1997.10a
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    • pp.145-154
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    • 1997
  • The results of optimum design by the deterministic approach adopted in the current design codes depend upon the safety levels of the applied code. But, it is now generally recognized that structural problems are nondeterministic and, consequently, that engineering optimum design must cope with uncertainties. Therefore, it is not an overstatement to affirm that the combination of reliability-based design procedures and optimization techniques is the only means of providing a powerful tool to obtain a practical optimum design solution. In the paper, reliability based optimum design procedure as a rational approach to optimum structural design is presented. The design constraints are formulated based on the ASD, LRFD and reliability theories. The reliability analysis is based on an advanced first-order second moment approach. Uncertainties in the structural strength and loading due to inherent variability as well as modeling and prediction errors are included in failure due to combined bending and shear. For the realistic reliability-based optimization of continuous steel box girder bridges, interactive non-linear limit state model is formulated based on the von Mises's combined stress yield criterion. Comparative results are presented when the ASD criteria are used for the optimum design of a structure under reliability constraints. In addition, this study comparatively shows the results of the optimum design for various criteria of design codes.

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