• Title/Summary/Keyword: MSO

Search Result 31, Processing Time 0.025 seconds

A Study on the Application of Pre-Indentation Technique for Fastener Hole Model (FASTENER HOLE 모델의 대한 예비압입 적용 연구)

  • Hwang,Jeong-Seon;Jo,Hwan-Gi
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.31 no.9
    • /
    • pp.26-31
    • /
    • 2003
  • Aging aircraft accumulates widespread fatigue damage commonly referred to as multiple site damage(MSO). For ductile material such as 2024-T3 aluminum, MSO may lower the service life below that which is predicted by conventional fracture mechanics. The present paper is concerned with the fatigue life extension by pre-indentation technique for thin 2024-T3 aluminum plate to decelerate the crack propagation rate in the panels with MSO. The panel with fastener holes can be simply modelled by Hole/Slot type Middle-Tension specimen. Results of fatigue testing show significantly improving failure cycles from 10 to 40 times. This retardation effect is decreased by increasing the loading level in the constant amplitude loading. In the sense of retardation mechanism, the crack propagation rate is gradually attenuated by entering the indentation mark and maintains at the lowest value for a long period after the edge of crack passes the center of indentation area.

Study on Post-Fire Safe Shutdown Analysis using an Imaginary Plant for Training (교육용 가상원전을 이용한 화재안전정지분석에 관한 연구)

  • Lee, Jaiho;Kim, Jin Hong
    • Fire Science and Engineering
    • /
    • v.32 no.1
    • /
    • pp.57-65
    • /
    • 2018
  • In this study, a post-fire safe shutdown analysis (PFSSA) including multiple spurious operation (MSO) treatments for cables was conducted with an imaginary nuclear power plant for training using a deterministic fire analysis code. The imaginary nuclear power plant for the training consisted of a reactor containment building and an auxiliary building, including a total of 22 fire areas. The equipment including valves, pumps, emergency diesel generators, switch gears, motor control centers, and logic controllers were located in each fire area of the imaginary plant. It was assumed that each equipment is connected with two cables and that each cable passes through the fire areas along the cable trays. A database containing the information on the equipment and cables for the imaginary plant was constructed for the fire area analysis. The fire area analysis was performed for several assumed MSO scenarios, equipment logics, and cable logics. A mitigation measure using a three hour rated wrap was applied to the failed cables and cable trays after the fire area analysis.

Identification of Non-mutans Streptococci Organisms in Dental Plaques Recovering on Mitis-Salivarius Bacitracin Agar Medium

  • Yoo So Young;Kim Pyung Sik;Hwan Ho Keel;Lim Seong Hoon;Kim Kwang Won;Choe Son Jin;Min Byung Moo;Kook Joong Ki
    • Journal of Microbiology
    • /
    • v.43 no.2
    • /
    • pp.204-208
    • /
    • 2005
  • The objective of this study was to both isolate and identify non-mutans streptococci organisms (non­MSO) from dental plaques recovered on mitis-salivarius sucrose bacitracin agar (MSB) plates. The dental plaque samples, which had been collected from 63 human subjects, were diluted and plated on MSB. The bacteria growing on the MSB plates were then identified with biochemical tests, as well as with 16S rDNA cloning and sequencing techniques. Our data indicated that bacteria from 30 subjects had been recovered on the MSB plates. Among the 21 typical colonies selected from the 30 subjects, 12 colonies, derived from 10 subjects, were identified as non-MSO. These 12 colonies were determined to be Streptococcus anginosus (8 colonies), S. sanguinis (1 colony), and Pantoea agglomerans (3 colonies). These results strongly suggest that a new selective medium will be required for the reliable isolation of mutans streptococci.

Identification of Potential Crossbreeds of Mulberry Silkworm, Bombyx mori L. and Their Performance Under Tropical Stress

  • Seshagiri, SureVenkata;Naik, S. Sankar;Goel, Ajay Kumar;Raju, P.J.
    • International Journal of Industrial Entomology and Biomaterials
    • /
    • v.22 no.2
    • /
    • pp.45-49
    • /
    • 2011
  • The performance of five newly evolved cross breeds were evaluated across seasons to understand the genotype and environment interactions and their stability under fluctuating tropical environmental conditions along with control hybrids $PM{\times}CSR2$ and $APM1{\times}APS8$. The data was collected on eight economic traits namely fecundity, yield per 10,000 larvae by number, yield per 10,000 larvae by weight, survival rate, cocoon weight, cocoon shell weight, cocoon shell ratio and filament length. The data was subjected for Analysis of Variance (ANOVA) and relevant statistical methods. The performance data obtained was further subjected for multiple trait evaluation index method. The ranks were adjudicated based on the index values. The two hybrids viz., $MSO3{\times}APS45$ and $MSO1{\times}APS12$ performed well under diversified environmental conditions indicating their overall stability and superiority. These hybrids revealed highly significant (p < 0.01) improvement for the majority of the traits over the control hybrids.

Development of Walk-down Performance Procedures for Fire Modeling of Nuclear Power Plants based on Deterministic Fire Protection Requirements (결정론적 화재방호요건을 기반으로 한 원자력발전소 화재모델링 현장실사 수행절차 개발)

  • Moon, Jongseol;Lee, Jaiho
    • Fire Science and Engineering
    • /
    • v.33 no.6
    • /
    • pp.43-52
    • /
    • 2019
  • A walk-down procedure for fire modeling of nuclear power plants, based on deterministic fire protection requirements, was developed. The walk-down procedure includes checking the locations of safety shutdown equipment and cables that are not correctly indicated on drawings and identifying the existence and location of combustibles and ignition sources. In order to verify the performance of the walk-down procedure developed in this study, a sample of important equipment and cables were selected for hypothetical multiple spurious operation (MSO) scenarios. In addition, the hypothetical fire modeling scenarios were derived from the selected safe shutdown equipment and cables and an actual walk-down was conducted. The plant information collected through the walk-down was compared to the information obtained from the drawings, so that the collected information may be used as input values for the fire modeling.

A study on the adaptive query conversion using TMDR-based global query (TMDR 기반의 글로벌 쿼리를 이용한 적응적 쿼리 변환에 관한 연구)

  • Hwang, Chi-Gon;Shin, Hyo-Young;Jung, Kye-Dong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2012.10a
    • /
    • pp.966-969
    • /
    • 2012
  • This study suggests a query conversion method based on Topic Maps MetaData Registry(TMDR) in order to solve heterogeneity problems distributed in networks and to integrate data efficiently. In order to integrate distributed data, TMDR provides global schema and it solves heterogeneity problem within local data using query conversion method. After analyzing relationship between Meta Schema Ontology(MSO) of eXtended Meta Data Registry(XMDR) and Topic Maps, this method allows integrated access through Meta Location(ML) which manages accessing information of local data. The processing method is to produce a global query for global processing by using TMDR and then to make the produced global query approach to systems distributed through networks so that allows integrated access at the end. For this, we propose a method to convert a global query into a query which is adaptive to local query.

  • PDF

A Study on the Development of a Training Course for Maritime Security Operatives (해상특수경비원 교육과정 개발에 관한 연구)

  • Doo, Hyun-Wook;Ahn, Young-Joong;Jo, So-Hyun
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.24 no.2
    • /
    • pp.223-231
    • /
    • 2018
  • In West Africa and Southeast Asia including Somalia, piracy attacks still take place that threaten safety of ships and the lifes of seafarers. In order to protect Korean flag ships and the seafarers on board from piracy attacks, the government of the Republic of Korea established the Act to Prevent Piracy Attacks on International Ships on Dec. 27, 2016. This act legally provides for the establishment of Maritime Security Operatives (MSO) on board ships navigating high risk areas to ensure security. Furthermore, mandated training for MSOs is required to prepare them to carry out their duties effectively. In this paper, a new training course for MSOs according to domestic law is suggested through analysis of IMO documents and the MSO training provided by foreign nations.

Experimental Study on the Two Phase Thermosyphone Loop with Parallel Connected Multiple Evaporators under Partial Load and Low Temperature Operating Condition (병렬 연결된 다중 증발기 구조 2상 유동 순환형 열사이폰의 부분부하 및 저온운전 특성에 관한 실험적 연구)

  • Kang In-Seak;Choi Dong-Kyu;Kim Taig-young
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.16 no.11
    • /
    • pp.1051-1059
    • /
    • 2004
  • Two phase thermosyphone loop for electronics cooling are designed and manufactured to test its performance under the partial load and low environment temperature conditions. The thermosyphone device has six evaporators connected parallel for the purpose of cooling six power amplifier units (PAU) independently. The heater modules for simulating PAUs are adhered with thermal pad to the evaporator plates to reduce the contact resistance. There are unbalanced distributions of liquid refrigerant in the differently heated evaporators due to the vapor pressure difference. To reduce the vapor pressure differences caused by partial heating, two evaporators are connected each other using the copper tube. The pressure regulation tube successfully reduces these unbalances and it is good candidates for a field distributed systems. Under the low environment temperature operating condition, such as $-30^{\circ}C$, there may be unexpected subcooling in condenser. It leads the very low saturation pressure, and under this condition there exists explosive boiling in evaporator. The abrupt pressure rise due to the explosive boiling inhibits the supplement of liquid refrigerant to the evaporator for continuous cooling. Finally the cooling cycle will be broken. For the normal circulation of refrigerant there may be an optimum cooling air flow rate in condenser to adjust the given heat load.