• 제목/요약/키워드: Primary pressure

검색결과 1,088건 처리시간 0.03초

Flaw Assessment Method of Pressure Tube in CANDU Reactor

  • Kim, Jung-Gyu;Na, Bok-Gyun;Hwang, Jong-Keun;Park, Keon-Woo
    • 한국원자력학회:학술대회논문집
    • /
    • 한국원자력학회 1996년도 춘계학술발표회논문집(1)
    • /
    • pp.291-295
    • /
    • 1996
  • In CANDU reactor, each pressure tubes contain twelve fuel bundles and provide the inlet and outlet for the primary coolant. If a leak develops in the pressure tube, it is detected by Annulus Gas System which contains circulating dry $CO_2$ gas. Since the leaks caused by the flaws are resulted in pressure tube break, establishment of flaw assessment method is very significant in view of the fracture mechanics. In this paper, various criteria for assessing the flaws are presented to prevent the tube rupture and ensure the integrity of reactor operating.

  • PDF

The Effectiveness of Noninvasive Positive Pressure Ventilation in Subarachnoid Pleural Fistula: A Case Report and Literature Review

  • Soundararajan, Dilip Chand Raja;Shetty, Ajoy Prasad;Kanna, Rishi Mugesh;Rajasekaran, S.
    • Neurospine
    • /
    • 제15권4호
    • /
    • pp.394-399
    • /
    • 2018
  • Subarachnoid pleural fistula (SPF) is an aberrant communication between the pleural cavity and subarachnoid space, resulting in uncontrolled cerebrospinal fluid drainage. The negative pressure of the pleural cavity creates a continuous suctioning effect, thereby impeding the spontaneous closure of these fistulas. Dural tears or punctures in cardiothoracic procedures, spinal operations, and trauma are known to cause such abnormal communications. Failure to recognize this entity may result in sudden neurological or respiratory complications. Hence, a high index of suspicion is required for early diagnosis and prompt management. Noninvasive positive pressure ventilation has been described to be effective in managing such fistulas, thus mitigating the high morbidity associated with exploratory surgery for primary repair. Herein, we describe the typical presentation of SPF and the clinical course, treatment, and follow-up of a patient who sustained SPF following anterior thoracic spinal surgery.

국민학생의 6년간 혈압의 변화양상과 혈압변화와 관련된 요인 분석 (The change in blood pressure and factors affecting the change in blood pressure for Korean children: A six-year follow-up study)

  • 서일;이순영;남정모;김일순
    • Journal of Preventive Medicine and Public Health
    • /
    • 제26권1호
    • /
    • pp.96-109
    • /
    • 1993
  • For the purposes of analyzing the distribution and the change in blood pressure according to age and determining the factors affecting the change in blood pressure, a follow-up study had been conducted for 6 years from 1986 to 1991 for 430 primary school children aged 6 years old in 1986 in Kangwha County, Korea. The mean blood pressure increased according to age. Specifically mean systolic blood pressure increased from 97.3 mmHg for male and 96.4mmHg for female (at 6 years of age) to 108.8mmHg fur male and 112.1mmHg for female (at 11 years of age). Mean diastolic blood pressure increased from 60.0mmHg for male and 61.8mmHg for female (at 6 years of age) to 72.9mmHg for male and 73.8mmHg for female (at 11 years of age). The average annual increase in blood pressure was 2.3mmHg (in systolic blood pressure) and 2.6 mmHg (in diastolic blood pressure) for male : and 3.1mmHg (in systolic blood pressure) and 2.4mmHg (in diastolic blood pressure) for female, respectively. To determine the factors affecting the change in blood pressure, the stepwise regression analysis was conducted. Children were divided into the three groups(low, middle, and upper) according to the level of systolic and diastolic blood pressure at the age of 6, and the regression analysis was performed in each group. For the change in systolic blood pressure, the changes in weight and skinfold thickness or initial skinfold thickness fer male, and the change in weight for female were selected as significant factors for children in middle and upper group. For the change of blood pressure in diastolic blood pressure, no variables was significant.

  • PDF

Competitive Pressure and Business Performance in East Java Batik Industry

  • SOEWARNO, Noorlailie;TJAHJADI, Bambang;PERMATANADIA, Devitania
    • The Journal of Asian Finance, Economics and Business
    • /
    • 제7권12호
    • /
    • pp.329-336
    • /
    • 2020
  • This study aims to assess the impact of competitive pressure and innovation capability on business performance in small- and medium-sized enterprises (SMEs) in the batik industry in East Java, Indonesia. Furthermore, this study explores the impact of competitive pressure on business performance through innovation capability as a mediating variable. This research was quantitative using primary data with questionnaire as a method of sampling collection. The measurement of the variables was captured using Likert scale. The respondents were small- and medium-sized enterprises (SMEs) in the batik industry in East Java Province, Indonesia. The sample totaled 254 subjects. The data analysis was done using SEM-PLS. The results of the study show that: 1) there was a positive direct impact of competitive pressure on business performance; 2) competition pressure positively influences innovation capability; 3) innovation capability positively influences business performance; and 4) innovation capability has a partial mediating role in the effect of competitive pressures on business performance. The findings of this study suggest that managers in SME's batik industry should increase their effort to cope with the high competitive pressure to increase the innovation capability, so that they can have an advantage to face successfully competitors, leading to higher business performance.

Work Pressure and Safety Behaviors among Health Workers in Ghana: The Moderating Role of Management Commitment to Safety

  • Amponsah-Tawaih, Kwesi;Adu, Michael Appiah
    • Safety and Health at Work
    • /
    • 제7권4호
    • /
    • pp.340-346
    • /
    • 2016
  • Background: safety and healthy working environment has received numerous research attention over the years. Majority of these researches seem to have been conducted in the construction industry, with little attention in the health sector. Nonetheless, there are couple of studies conducted in Africa that suggest pressure in hospitals. Therefore the aim of the study was to examine how pressure influence safety behavior in the hospitals. With reference to the relevance of safety behavior in primary health care delivery, there was the need for the study. Method: Data was obtained from 422 public hospital employees. Respondents were assured that all information would be kept confidential to increase the response rate and acquire more accurate information. Collection of questionnaires from participants took four weeks (20 working days), after which the data was analyzed. Results: The result of the study showed that work pressure correlated negatively with safety behavior. General safety climate significantly correlated positively with safety behavior and negatively with work pressure, although the effect size for the latter was smaller. Hierarchical regression analysis showed management commitment to safety to moderate the relationship between work pressure and safety behavior. Conclusion: When employees perceive safety communication, safety systems and training to be positive, they seem to comply with safety rules and procedures than voluntarily participate in safety activities.

초고압 압력용기에서 메탈시일의 설계 안전성에 관한 연구 (A Study on the Design Safety of Metal Seals in High Pressure Vessels)

  • 김청균
    • 한국가스학회지
    • /
    • 제9권1호
    • /
    • pp.26-32
    • /
    • 2005
  • 본 논문에서는 고압용기의 밀봉을 위해 사용하는 메탈시일의 설계 안전성에 대한 연구결과를 제시하고 있다. 기본적으로 고압용기의 1차적 밀봉은 메탈시일에 의해 이루어지고, 2차적 밀봉은 탄성체 고무로 제작된 0-링에 의해 가스누출이 차단된다. 유한요소해석 결과에 의하면, 가스누출 차단을 위해 사용한 알루미늄 소재의 밀봉장치는 강재를 사용한 경우보다 우수한 밀봉성을 보여주고 있다. 이것은 알루미늄 소재의 열팽창 특성이 상대적으로 우수하기 때문이다. 메탈시일과 압력용기 구조물에 걸리는 변형과 응력분포는 외부에서 공급된 가스압보다는 용기 내부에서 전달된 온도차에 의해 크게 지배를 받는 것으로 알려져 있다. 따라서 메탈시일의 소재는 통상적으로 $200^{\circ}C$이하로 유지되는 것이 소재의 강도와 밀봉성 측면에서 안전하다.

  • PDF

Failure Pressure Prediction of Composite Cylinders for Hydrogen Storage Using Thermo-mechanical Analysis and Neural Network

  • Hu, J.;Sundararaman, S.;Menta, V.G.K.;Chandrashekhara, K.;Chernicoff, William
    • Advanced Composite Materials
    • /
    • 제18권3호
    • /
    • pp.233-249
    • /
    • 2009
  • Safe installation and operation of high-pressure composite cylinders for hydrogen storage are of primary concern. It is unavoidable for the cylinders to experience temperature variation and significant thermal input during service. The maximum failure pressure that the cylinder can sustain is affected due to the dependence of composite material properties on temperature and complexity of cylinder design. Most of the analysis reported for high-pressure composite cylinders is based on simplifying assumptions and does not account for complexities like thermo-mechanical behavior and temperature dependent material properties. In the present work, a comprehensive finite element simulation tool for the design of hydrogen storage cylinder system is developed. The structural response of the cylinder is analyzed using laminated shell theory accounting for transverse shear deformation and geometric nonlinearity. A composite failure model is used to evaluate the failure pressure under various thermo-mechanical loadings. A back-propagation neural network (NNk) model is developed to predict the maximum failure pressure using the analysis results. The failure pressures predicted from NNk model are compared with those from test cases. The developed NNk model is capable of predicting the failure pressure for any given loading condition.

해석학적모델을 이용한 하계 대구지방의 열적저기압 형성에 관한 연구 (On the Thermal Low-pressure Onset using Analytical Model around Daegu in Summer)

  • 김해동;정우식
    • 한국환경과학회지
    • /
    • 제11권10호
    • /
    • pp.1133-1140
    • /
    • 2002
  • The growth and extent of the local pressure field at any point is of primary importance as it supplies the driving force for the local wind circulation which causes a medium-range transport of air pollutants. The local pressure field is produced by the variation of temperature in the lower layers of the atmosphere, and is called the thermal wave. The thermal wave is influenced by the difference in the diurnal variations between two regions with different surface condition, for example land and sea. This difference produces the land- and sea-breeze phenomenon, and brings corresponding variations in the form of the thermal wave. Daytime temperature over the inland area (Daegu) was higher than that of the coastal area (Busan). The temperature difference reached about 5~6$^{\circ}C$ in the late afternoon(30-31 May 1999). The low pressure system of Daegu was most fully developed at the time. In this study, we investigated the possibility of thermal low onset around Daegu in summer with an analytical model. The topography effect was neglected in the model. We could predict a thermal low-pressure of about 3.4hPa at Daegu with wide flat land surface, when the inland area is about 6K warmer than the coastal area temperature. The pressure decrease is somewhat less than the observed value(4~5 hPa).

근로자의 건강상태 추이 분석 -고혈압, 간장질환 환자대조군 연구- (Analysis of the Trend of Employee's Health Status -Case Control Study for Hypertensive, Liver Diseased Employees-)

  • 한미경
    • 한국직업건강간호학회지
    • /
    • 제4권호
    • /
    • pp.84-101
    • /
    • 1995
  • The periodic health examination have been shown the important role on early detection, early treatment and prevention of disease. Until now, there have been many studies that showed the effectiveness of the periodic health examination on the early detection and early treatment of disease to some extent. But there are few studies about primary prevention before health problem arise. In this case-control study, 29 newly detected hypertensive cases, 31 liver disease cases and 65 controls which are all available for 6-year data in the periodic health examination of a occupational field were compared to investigate the significant increase trend of health status between the groups. The results will be used for the occupational health nurses to provide appropriate primary prevention to the employees. The hypertensive and liver disease cases were divided observation-needed group and treatment-needed group. The data on systolic blood pressure, diastolic blood pressure, Body Mass Index and Broca Index in hypertensive cases and SGOT, SGPT, Body Mass Index and Broca Index in liver disease cases were analyzed by t-test and ANOVA. The specific findings are summarized as follows. 1. In the comparison between the hypertensive cases and controls, SBP and DBP of the observation-needed group and the treatment-needed group were significantly higher than the data of the controls for past 6 years. It was 2-3 years ago showing increase over 140/90mmHg of blood pressure in the hypertensive cases before they are categorized as hypertensive cases. In the observation-needed group and the treatment-needed group, the trend of the blood pressure for 6 years were significantly higher than the one of the controls. 2. In the comparison between the liver disease cases and controls, SGOT and SGPT of the observation-needed group and the treatment-needed group were significantly higher than the data of the controls for past 6 years. It was 2 years ago showing increase within upper normal limit of SGOT and 5 years ago of SGPT in the liver disease cases before they are categorized as liver disease cases. In the observation-needed group and the treatment-needed group, the trend of the liver enzyme for 6 years were significantly higher than the one of the controls. With these results, the author proposed that intervention for the primary prevention such as continuous follow-up, health education and weight control to the population who has over 140/90mmHg of blood pressure and upper normal limit of AST and ALT.

  • PDF

승용차 실내소음의 전달경로 해석 (Transfer Path Analysis on the Passenger Car Interior Noise)

  • 지태한;최윤봉
    • 소음진동
    • /
    • 제9권1호
    • /
    • pp.97-102
    • /
    • 1999
  • Structure-borne noise is an important aspect to consider during the design and development of a vehicle. In this work. it was desired to identify the primary paths associated with structure-borne noise generated from the engine and front suspension. An experimental source-path-receiver model was used to characterize the system. A variety of primary sources such as engine. tires or exhaust system generate vibrations of the inner surfaces of the passenger compartment of a vehicle which subsequently radiate noise. The source was characterized by the force acting at the engine-to-body interface. and the path was characterized by pressure over force FRF's. The excitation forces were indirectly determined using dynamic stiffness of rubber mount or the system accelerance matrix. Through these analysis, path contribution diagram which is well expressed primary noise path is obtained.

  • PDF