• Title/Summary/Keyword: Pressure Test

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Pore Pressure Behavior of Normally Consolidated Deep Sea Clay (정규압밀된 심해점토의 간극수압 거동)

  • 박용원
    • Geotechnical Engineering
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    • v.6 no.4
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    • pp.65-74
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    • 1990
  • This paper presents triaxial test (CIVC and CKOUC) results on normally consolidated deep sea clay samples. Based on the test results the pore pressure-strain relations for both isotropicaly and anisotropicaly consgidated samples are expressed with hyperbolic functions of the major princpal strain. The analysis of the difference in pore pressure behavior due to the anisotropy in consolidation stress is carried out with the effective stress pathos of CIVC and CKOUC and finds a factor which correlates the pore pressure of two types of test.

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In Vitro Test of Seiong Pediatric Ventricular Assist Device (소아용 보조인공심장의 모의순환 실험에 관한 연구)

  • 권혁남;박표원
    • Journal of Biomedical Engineering Research
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    • v.12 no.1
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    • pp.29-34
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    • 1991
  • Ventricular assist device(VAD) has been clinically applied as a temporary circulatory sup- porting system in the patients with severe heart failure, but small sized VAD for infant is not available. The purpose of tilis paper is to introdIAce small sized VAD and presents the result of in vitro test. Sejong VAD is diaphragmatic type of pneumatic pump and stroke volume is 11cc. Cardiac outputs of the Sejong VAD were measured by overflow tank under variable conditions of driving parameters. The cardiac output was 1.3 1/min at the heart rate of 120 per minute, left atrial pressure of $15cmH_2O$, percent systole of 43%, driving pressure of 240 mmHg, vacuum pressure of -40 mmHg, and mean aortic pressure of 70 mmHg. No mechanical problem was developed during the continuous in vitro test for 3 months.

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Field Test of Recycled Aggregates and Crushed Stone as Horizontal Drains (수평배수재용 순환골재와 쇄석의 현장시험)

  • Kim, Si-Jung;Lee, Dal-Won
    • Journal of The Korean Society of Agricultural Engineers
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    • v.54 no.1
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    • pp.39-45
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    • 2012
  • In this study, field test on utilization of recycled aggregates and crushed stone as horizontal drains to use an alternative material of sand in soft ground is practiced. The settlement with time showed similarly ranged from 28.4-30.3 cm in the all horizontal materials. The excess pore water pressure of the recycled aggregates and crushed stone showed smaller than sand. The small the excess pore water pressure becomes faster the consolidation period and it can reduces the amount of residual settlement. Therefore, it was verified as having enough to an alternative materials that the field applicability is excellent. The distribution of earth pressure with time showed similarly in the all horizontal materials. The recycled aggregates and crushed stone was very applicable to practice because there is no mat resistance in the horizontal drains layer. The penetration rate in the SCP and PVD improvement sections did not show large differences as the grain size and the horizontal drainage height increases.

Tank Pressure Control of PWM Sol V/V for Thrust Control of Launch Vehicle (발사체 추력제어 안정성을 위한 PWM 솔밸브의 탱크압력제어)

  • Lee, Joong-Youp;Hong, Moon-Geun;Han, Sang-Yeop;Kim, Young-Mog
    • 유체기계공업학회:학술대회논문집
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    • 2006.08a
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    • pp.565-568
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    • 2006
  • This paper achieved dynamic characteristics with test to use solenoid valve for flight model that have present. Designed pressure control virtual system which PWM solenoid valve to use test result. Examination compared solenoid valve dynamic characteristics in atmosphere and cryogenic fluid and presented technique and valuation method that measured upstream and down stream pressure of solenoid valve, as well as, temperature, excitation voltage etc. These test results could confirm solenoid valve response time and maximum using frequency characteristic at use in atmosphere and cryogenic temperature and this derived design variables pressure control system from those bases.

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Reliability of Plantar Pressure Measures Using the Parotec System (Parotec System을 이용한 족저압 측정의 신뢰도)

  • Roh, Jung-Suk;Kim, Tack-Hoon
    • Physical Therapy Korea
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    • v.8 no.3
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    • pp.35-41
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    • 2001
  • In-shoe measurement systems allow the clinician and researcher to examine the pressure parameters within the shoe. The purpose of this study was to investigate the test-retest reliability of plantar pressures using the Parotec system over speeds and plantar regions. Seventeen healthy subjects were recruited for the study. Sampling rate was 100 Hz, and data of six variables (pressure on medial heel, lateral heel, 1st metatarsal head, 5th metatarsal head, and great toe and total impulse) were collected in four different gait speed (1.0 m/sec, 1.5 m/sec, 2.0 m/sec, and comfortable walking speed) in each day. The result indicates fair to excellent reliability between the two day test. Intraclass correlation coefficients (ICCs) ranged from .693 to .979, and range of reliability was similar depending on the speed and plantar region. In most cases, data recorded by the Parotec systems provide good evidence for the reliability.

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An Experimental Study of Pressure Drop Correlations for Wire-Wrapped Fuel Assemblies

  • Chun, Moon-Hyun;Seo, Kyong-Won;Park, Seok-Ki;Nam, Ho-Yun
    • Journal of Mechanical Science and Technology
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    • v.15 no.3
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    • pp.403-409
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    • 2001
  • The main objective of the present study is to perform an experimental evaluation of five existing correlations for the subchannel pressure drop analysis of a wire-wrapped fuel assembly. For this purpose, a series of water experiments have been performed using a helical wire-wrapped 19-pin fuel assembly for various test parameters. Four different test sections with different pitch to rod diameter ratios (P/D) and wire lead length to rod diameter ratios (H/D) have been fabricated. A series of pressure drop measurements were made to obtain friction factors for these four test sections. The new data along with existing data are used to evaluate existing correlations. Both the original and the simplified Cheng and Todreas correlations give the best agreement with experimental data for all flow regions.

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Hydride Embrittlement Behavior at the LBB Evaluation of PHWR Pressure Tube (중수로 압력관 LBB 평가에서의 수소화물에 의한 취화거동)

  • Oh, Dong-Joon;Kim, Young-Suk
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.1192-1197
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    • 2003
  • The aim of this study is to investigate the hydride embrittlement when the LBB evaluation is carried out for the integrity of PHWR Pressure Tubes. The transverse tensile and CCT tests were performed at three hydrogen concentrations while the test temperatures were changed (RT to $300^{\circ}C$). The specimens were directly machined from the pressure tube retaining original curvature. Both the transverse tensile and the fracture toughness tests showed the hydrogen embrittlement clearly at RT but this phenomenon was disappeared while the test temperature arrived over $250^{\circ}C$. Using the DHC test results, the CCL and LBB time were calculated and compared. The hydride embrittlement behavior at the LBB evaluation was definitely showed.

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Experience for development and capacity certification of safely relief valves (안전방출밸브 개발과 용량인증 사례)

  • Kim, Chil-Seong;No, Hui-Seon;Kim, Gang-Tae;Kim, Ji-Heon;Kim, Jong-Su
    • 유체기계공업학회:학술대회논문집
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    • 2004.12a
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    • pp.492-500
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    • 2004
  • The purpose of this study is localization of safety relief valves fur Nuclear Service through technical development with overall design, fabrication, inspection, capacity certification test and functional qualification test of safety relief valves in accordance with KEPIC MN Code(or ASME Sec.III ). The safely relief valve is the important equipment used to protect the pressure vessel, the steam generator and the other pressure facility from overpressure by discharging the operating medium when the pressure of system is reaching the design pressure of the system. But we're depending on technology of the other country up to the present time. Because we don't have our own technologies, we have been spent the great time and money on installing and repairing safety relief valve at nuclear power plant. Therefore we have to achieve the development of safety relief valves for Nuclear Service with our own technologies.

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A Development of Proportional Pressure Control Valve (비례압력제어밸브 개발)

  • Yun, S.N.;Ahn, B.K.;Ryu, J.S.;Ham, Y.B.
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.1041-1046
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    • 2004
  • A proportional pressure control valve has a nonmagnetic ring which is inserted in between a coil and plunger and it can get attraction force in proportion to input current by an influence of control cone. Therefore, a proportional pressure control valve is applied to a servo system as substitution of servo valve and an on-off solenoid valve widely because control of a high level is possible and pollution level is low. The purpose of this study is to develop domestic model of a proportional pressure control valve, and a test model was designed and manufactured through valve system analysis and finite element analysis. And comparison between results of theoretical analysis and static / dynamic characteristics test were carried out on a manufactured test model, and it was confirmed that it has excellent performance in comparison with other foreign products.

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Development of Pyrogen Igniter for Kick Motor

  • Koh, Hyeon-Seok;Kil, Gyoung-Sub;Cho, In-Hyun;Kim, Yong-Woon
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2008.03a
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    • pp.301-306
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    • 2008
  • A pyrogen igniter was designed to satisfy the required condition of kick motor system for the space launch vehicle. We analyzed the ignition characteristics and performed the combustion tests to verify the internal ballistic performance. In the design process, the arc-image test was carried out to find the sufficient heat flux as varying the initial pressure from 10 to 700kPa. The analysis indicated that the initial pressure condition would delay ignition time within a range from 100 to 500ms. The combustion test with an inert chamber was also performed to understand the ignition characteristics with the variation of the initial pressure of free chamber volume. Finally, we confirmed that the igniter could provide the acceptable energy to ignite the propellant of kick motor at the ground test. The result of the ground tests showed that the ignition delay time was within the design range at the atmospheric pressure condition.

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