• Title/Summary/Keyword: Passive Type

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Simulation and transient analyses of a complete passive heat removal system in a downward cooling pool-type material testing reactor against a complete station blackout and long-term natural convection mode using the RELAP5/3.2 code

  • Hedayat, Afshin
    • Nuclear Engineering and Technology
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    • v.49 no.5
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    • pp.953-967
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    • 2017
  • In this paper, a complete station blackout (SBO) or complete loss of electrical power supplies is simulated and analyzed in a downward cooling 5-MW pool-type Material Testing Reactor (MTR). The scenario is traced in the absence of active cooling systems and operators. The code nodalization is successfully benchmarked against experimental data of the reactor's operating parameters. The passive heat removal system includes downward water cooling after pump breakdown by the force of gravity (where the coolant streams down to the unfilled portion of the holdup tank), safety flapper opening, flow reversal from a downward to an upward cooling direction, and then the upward free convection heat removal throughout the flapper safety valve, lower plenum, and fuel assemblies. Both short-term and long-term natural core cooling conditions are simulated and investigated using the RELAP5 code. Short-term analyses focus on the safety flapper valve operation and flow reversal mode. Long-term analyses include simulation of both complete SBO and long-term operation of the free convection mode. Results are promising for pool-type MTRs because this allows operators to investigate RELAP code abilities for MTR thermal-hydraulic simulations without any oscillation; moreover, the Tehran Research Reactor is conservatively safe against the complete SBO and long-term free convection operation.

A Study on Three-phase Imbalance of a Power Transmission Line due to Installation of a Passive Loop Conductor (수동루프에 의한 송전선로 상불평형 발생에 관한 연구)

  • 김종형;신명철;최상열
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.17 no.6
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    • pp.31-38
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    • 2003
  • Among mitigation techniques for electric and magnetic field (EMF) from an overhead transmission line a passive loop is a way that can be cheap and easily installed on the existing towers and have a satisfactory effect as well. However current induced in the passive loop causes transmission power loss and the phase imbalance increases since geometrical asymmetry of the transmission lines becomes larger. So in order to evaluate the power loss and the phase imbalance due to a passive loop, this paper represent a 345[kV] 1-circuit flat type transmission line as asymmetrical 3-phase distributed parameter line model where the effect of a passive loop is embedded in the line parameters, and then formulates differential equations. By solving these equations voltages and currents of each phase at receiving end become known. We find out that power losses occur differently at each phase and positive sequence component decreases at receiving end while negative sequence component increase. In general phase imbalance due to a passive loop is slight, but it increases in proportional to the induced current and length of section where the passive loop is installed. Thus the phase imbalance should be included in terms of cost for introducing a passive loop.

The Study on the Socialization of Household Work to the difference of Life Style pattern (생활 양식 유형에 따른 가사노동 사회화에 관한 연구)

  • 문숙재
    • Journal of the Korean Home Economics Association
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    • v.26 no.3
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    • pp.153-169
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    • 1988
  • This study aimed at investigating the socialization of householdwork to the difference of life style pattern of housewives. For the purpose, questionnaires were administrated to the housewives in Seoul and to analyse of the date, factor analysis F-test, t-test and path analysis were used. The results can be summarized as follows ; 1. By utilizing factor analysis, the life style patterns of housewives were classified into 7 types, they were named, self-improvement type, social activity type, modernistic type, sound and thrifty type, variety-seeking type, passive stability-seeking type, the traditional and conservative type. And the patterns of life style differed significantly according to all of the demographic variables except family type. 2. The level of socialization of householdwork was not reaching the medium, and the mean was 19.45. 3. The socialization of householdwork were influenced indirectly by the age, educational level, income level, family type and social activity type, variety seeking type, traditional and conservative type of the life style pattern. And directly, the age and educational level influenced the socialization of householdwork.

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Types of Nurse's Attitudes Toward the Aging Process A Q-Methodological Approach (늙어감에 대한 간호사의 태도 - Q 방법론적 접근 -)

  • Jo, Kae-Hwa;An, Gyeong-Ju
    • Journal of Korean Academy of Nursing
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    • v.37 no.6
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    • pp.823-834
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    • 2007
  • Purpose: The purpose of this study was to analyze types of nurse's attitudes toward the aging process. Methods: A Q-methodology which provides a method of analyzing the subjectivity of each item was used. Thirty-four selected Q-statements from each of 38 subjects were classified into a shape of normal distribution using a 9 point scale. The collected data was analyzed using a QUANL PC program. Results: Five types of attitudes towards the aging process from research subjects in Korean nurses were identified. Type I is a positive acceptance type, Type II is a negative acceptance type, Type III is a passive coping type, Type IV is an active coping type, and Type V is an ambiguous acceptance type. Conclusion: The results of the study indicate that different approaches of educational programs for elderly care are recommended based on the five types of nurse's attitude toward the aging process.

Types of Anger Expression in Adolescent Women - A Q-Methodological Approach - (청소년기 여성의 분노표현 유형 - Q방법론적 접근 -)

  • Moon, So-Hyun;Park, Young-Joo
    • Journal of Korean Academy of Nursing
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    • v.38 no.4
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    • pp.522-532
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    • 2008
  • Purpose: The purpose of this study was to identify the types of anger expression in adolescent women. Methods: The Q-Methodology which provides a method of analyzing the individual's subjectivity was used. The 32 subjects classified 50 selected Q-statements on a 9 point scale to make a normal distribution. The collected data was analyzed by a PC-QUANL program. Results: Five types of anger expression in adolescent women were identified. Type I: Direct attacking expression type, Type II: Mature consideration type, Type III: Passive indirect expression type, Type IV: Avoidance conversion type, and Type V: Expression control type. Conclusion: This study revealed that different approaches of nursing intervention strategies are recommended based on the five types of anger expression and their characteristics.

Female Adolescents' Sexual Assertiveness Types: Q Methodology (여성 청소년의 성적 자기주장 유형: Q 방법론 적용)

  • Kim, Hye Jin
    • Women's Health Nursing
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    • v.21 no.4
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    • pp.272-283
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    • 2015
  • Purpose: The purpose of this study was to identify the type of sexual assertiveness of female adolescents. Methods: A Q methodology which provided a method of analyzing the subjectivity of each type was used. Thirty-three female high school students classified 40 selected Q statements into 9 points standard. The collected data was analyzed by using the PC-QUNAL program. Results: Four types of sexual assertiveness manifested by female adolescents were identified: Type 1: Self-normative line-drawing type, Type 2: Pleasure-seeking negotiation type, Type 3: Passive relationship maintenance type, Type 4: future-oriented satisfaction-delay type. Conclusion: This study is meaningful because it provides empirical information necessary for the development of theories by verifying integrated attributes related to the female adolescents' sexual assertiveness. Results also induced the measuring tools and succeeding studies, and presented educational material for sex education that is tailored to the developmental level and characteristics of female adolescents.

Classification of Consumer Types by Moderation and Simplicity, Autonomy, and Income Level, and Comparison of Happiness Accordingly (절제와 간소, 자율성, 소득 수준에 따른 성인소비자 유형분류와 유형별 행복 비교)

  • Kim, Melean;Hong, Eunsil
    • The Korean Journal of Community Living Science
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    • v.27 no.1
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    • pp.31-47
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    • 2016
  • This research examines the effects of consumers' moderation and simplicity, autonomy, and income level on happiness, and based on this, classifies consumer types and examines the differences in consumer happiness and life happiness in accordance with this classification. The questionnaire survey was conducted on adults in their 20's through 60's. Moreover, hierarchical regression analysis, cluster analysis, and the analysis of variance were conducted. The results of this research are as follows. First, on consumer happiness, moderation and simplicity, income level, autonomy, education level, and gender had significant effects; on life happiness, moderation and simplicity, income level, autonomy, and education level had significant effects. Second, consumers were classified into three types according to moderation and simplicity, autonomy, and income level, and when making a comparison based on these factors between consumer happiness and life happiness, both consumer happiness and life happiness showed significant differences, but the detailed aspects were different. In the case of consumer happiness, non-autonomous moderation and simplicity type were reported to have the highest sense of happiness, followed by autonomous moderation and simplicity type, and passive moderation and simplicity type, but in the case of life happiness, autonomous moderation and simplicity type were reported to have the highest sense of happiness, followed by non-autonomous moderation and simplicity type, and passive moderation and simplicity type.

A Passive Control of Interaction of Condensation Shock Wave anc Boundary Layer(I) (응축충격파와 경계층 간섭의 피동제어(I))

  • Choe, Yeong-Sang;Jeong, Yeong-Jun;Gwon, Sun-Beom
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.2
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    • pp.316-328
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    • 1997
  • There were appreciable progresses on the study of shock wave / boundary layer interaction control in the transonic flow without nonequilibrium condensation. But in general, the actual flows associated with those of the airfoil of high speed flight body, the cascade of steam turbine and so on accompany the nonequilibrium condensation, and under a certain circumstance condensation shock wave occurs. Condensation shock wave / boundary layer interaction control is quite different from that of case without condensation, because the droplets generated by the result of nonequilibrium condensation may clog the holes of the porous wall for passive control and the flow interaction mechanism between the droplets and the porous system is concerned in the flow with nonequilibrium condensation. In these connections, it is necessary to study the condensation shock wave / boundary layer interaction control by passive cavity in the flow accompanying nonequilibrium condensation with condensation shock wave. In the present study, experiments were made on a roof mounted half circular arc in an indraft type supersonic wind tunnel to evaluate the effects of the porosity, the porous wall area and the depth of cavity on the pressure distribution around condensation shock wave. It was found that the porosity of 12% which was larger than the case of without nonequilibrium condensation produced the largest reduction of pressure fluctuations in the vicinity of condensation shock wave. The results also showed that wider porous area, deeper cavity for the same porosity of 12% are more favourable "passive" effect than the cases of its opposite. opposite.

Implementation of High-Quality Si Integrated Passive Devices using Thick Oxidation/Cu-BCB Process and Their RF Performance (실리콘 산화후막 공정과 Cu-BCB 공정을 이용한 고성능 수동 집적회로의 구현과 성능 측정)

  • 김동욱;정인호
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.15 no.5
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    • pp.509-516
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    • 2004
  • High-performance Si integrated passive process was developed using thick oxidation process and Cu-BCB process. This passive process leads to low-cost and high-quality RF module with a small form factor. The fabricated spiral inductor with 225 um inner diameter and 2.5 turns showed the inductance of 2.7 nH and the quality factor more than 30 in the frequency region of 1 ㎓ and above. Also WLCSP-type integrated passive devices were fabricated using the high-performance spiral inductors. The fabricated low pass filter had a parallel-resonance circuit inside the spiral inductor to suppress 2nd harmonics and showed about 0.5 ㏈ insertion loss at 2.45 ㎓. And also the high/low-pass balun had the insertion loss less than 0.5 ㏈ and the phase difference of 182 degrees at 2.45 ㎓.

Performance Enhancement Study Using Passive Control of Shock-Boundary Layer Interaction in a Transonic/Supersonic Compressor Cascade (천음속/초음속 압축기 익렬에서 Shock-Boundary Layer 상호작용의 수동적 제어에 의한 성능 향상 연구)

  • Kim, Sang-Deok;Gwon, Chang-O;Sa, Jong-Yeop
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.20 no.9
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    • pp.2944-2952
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    • 1996
  • In this paper the CSCM type upwind flux difference splitting Navier-Stokes method has been applied to study the ARL-SL19 transoni $c^ersonic compressor cascade flow. First, the general characteristics of baseline cascade flow were analyzed. At freestream Mach n.1.612 and exit/inlet pressure ratio 2.15, the results from current laminar flow were compared well in suction surface with the experiment; however, not well in pressure surface. Second, numerical study of the transoni $c^ersonic compressor cascade flow demonstrated the effectiveness of a passive control by the various size cavities. A cavity under the shock foot point at the suction surface of the blades was used as a passive control. The passive control of shock-boundary layer interaction by a cavity reduced total pressure losses. The effect of cavity length and depth was studied. The total pressure loss was reduced by about 10% and the isentropic efficiency was improved slightly. The effect of cavity depth in current study(d/l = 0.05, 0.02) was not found strong. Further adequate turbulence modeling and TVD schemes would help to capture the shock more accurately and increase the effectiveness of the current shock-boundary layer interaction study using upwind flux difference splitting computational methods.thods.