• Title/Summary/Keyword: diaphragm

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A Study on Flow Rate Characteristic and Dynamic Performance on Diaphragm Solenoid Valve (다이어프램형 밸브의 유량특성과 동적성능에 관한 연구)

  • Jeong, C.S.;Yang, S.Y.
    • Journal of Drive and Control
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    • v.10 no.3
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    • pp.27-33
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    • 2013
  • Solenoid valve has used in various industrial field extensively. A solenoid valve has different size, shape and method of operation accordantly to industrial field. Many researchers study on kinds of solenoid valve such as flow rate, dynamic, magnetic field, valve shape and operating method. But the flow rate characteristic and dynamic response time performance on the diaphragm valve are not studied. This paper describes the flow rate characteristic and dynamic response time performance on the diaphragm valve. At first, the diaphragm valve is simulated in AMESim simulation tool. AMESim model found that an effect of valve performance depends on parameter. The parameter is the diaphragm orifice area. And the performance test bench confirms the effect in this parameter. Finally, it finds out the flow rate characteristic and dynamic response time performance on the diaphragm valve.

Relationship Between Geometrical Stiffness of Diaphragm and Resonance Frequency for Micro-speaker (마이크로스피커 진동판의 등가탄성과 공명진동수의 연관성)

  • Oh, Sei-Jin
    • Korean Journal of Materials Research
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    • v.20 no.12
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    • pp.640-644
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    • 2010
  • Information technology devices, such as cellular phones, MP3s and so on, due to restrictions of space, require thin and small micro-speakers to generate sound. The reduction of the size of micro-speakers has resulted in the decrease of sound quality, due to such factors as frequency range and sound pressure level. In this study, the acoustical properties of oval microspeakers has been studied as a function of pattern shape on the diaphragm. The other conditions of micro-speakers, except for the pattern, was not changed. When the pattern is present on the diaphragm and the shape of pattern was a whirlwind, the resonance frequency was reduced due to the decrease of tensile strength of diaphragm. The patterns presented in the semi-minor axis of diaphragm did not effect a change of resonance frequency. However, increasing the number of patterns in the semimajor axis of diaphragm became a reason for the decrease of resonance frequency on edge side. When the depth of pattern on edge side was increased, the resonance frequency was decreased due to reduction of geometrical stiffness. If the height of edge and dome were increased, the resonance frequency and geometrical stiffness rapidly increased. After reaching the maximum values, they began to decrease with the continuous increase of height.

Flexural bearing capacity of diaphragm-through joints of concrete-filled square steel tubular columns

  • Rong, Bin;Liu, Rui;Zhang, Ruoyu;Chen, Zhihua;Apostolos, Fafitis
    • Steel and Composite Structures
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    • v.20 no.3
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    • pp.487-500
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    • 2016
  • In order to investigate the flexural bearing capacity of panel zone of diaphragm-through joint between concrete filled square steel tubular column and steel beam, four specimens were tested under static tension loads to study the mechanical properties and bearing capacity of diaphragm-through joints with a failure mode of panel zone. Finite element models of these specimens were developed to simulate the test and compare the predicted failure modes, load-displacement curves and bearing capacities with the experimentally observed. It was found that the tensile load from the steel beam flange is mainly shared by the square steel tube and the diaphragm. The diaphragm plastic zone appears along the cross-section lines enclosed by the square steel tube and the influence of steel beam web on the plastic zone of the steel tube is significant and cannot be neglected. Computational models of yield lines on square steel tube and diaphragm are established based on the distribution pattern of the plastic zone, and an analytical method for the evaluation of the bearing capacity of the joint is proposed. The theoretical results and the experimental data are compared and found in good agreement.

An evaluation equation of load capacities for CFT square column-to-beam connections with combined diaphragm

  • Choi, Sung-Mo;Jung, Do-Sub;Kim, Dae-Joong;Kim, Jin-Ho
    • Steel and Composite Structures
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    • v.7 no.4
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    • pp.303-320
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    • 2007
  • The objective of this study is to clarify the structural features of members consisting of connection, as a series of the previous study on the CFT column-to-beam tensile connection with combined cross diaphragm. This connection has the merits that the stress is distributed evenly on the beam flange and the diaphragm and the stress concentration is reduced, by improving the stress transfer route and restraining abrupt deformation of diaphragm. The finite element analysis was performed to find out the stress transfer through sleeve which is an important member of the connection with combined cross diaphragm. The length and thickness of sleeve were used as variables for the analysis. As the analysis results, the length and thickness of sleeve didn't influence on the capacity of the connection and played a role of a medium to transfer the stress from the diaphragm to the filled concrete. It is proposed that the appropriate length of sleeve be the same value as the diameter of sleeve and the appropriate ratio of sleeve diameter to sleeve thickness be 20. Two equations for evaluation of the load-carrying capacity of the connection were also proposed through the modification of the evaluation equation suggested in the previous study.

A Study on Performance Characteristics with the Control System of CNG Regulator (CNG 레귤레이터의 제어 방식에 따른 성능특성 연구)

  • Seo, Ji-Won;Yang, Jeong-Jik;Kim, Jin-Ho;Lim, Jong-Wan
    • Journal of the Korean Institute of Gas
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    • v.21 no.3
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    • pp.33-38
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    • 2017
  • The domestic vehicles remodeling the "CNG Bi-fuel Kit" are mostly in operation with installing the mechanical regulator applying the Diaphragm. However, due to the material characteristics of Diaphragm and characteristics of mechanical pressure control method, various problems are happening. This study tries to deduce the improvement plan through the checking of performance characteristics according to the pressure control method of CNG regulator and progress of comparative analysis. According to the test result, the decompression method applying the Diaphragm has advantage compared to the method applying the Piston. Furthermore, it was confirmed that through the electronic pressure control, it is possible to improve the general performance of the regulator.

Structural Characteristic of Beam-to-Column Connections in Rectangular CFT Structures Considering Concrete Filling (충전성을 개선한 각형CFT 기둥-보 접합부의 구조 특성)

  • Park, Je Young;Lee, Myung Jea
    • Journal of Korean Society of Steel Construction
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    • v.25 no.2
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    • pp.187-196
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    • 2013
  • CFT structures require a diaphragm to prevent buckling of steel at connections. An outer diaphragm has better concrete filling than a through diaphragm due to a large bore, but due to the larger size than the through diaphragm, it has poorer constructability and cooperation with building equipment. The building structure has a floor slab that was unified with the upper diaphragm, so the outer diaphragm was placed at the upper bound. Moreover, the through diaphragmwas placed at the lower connection to avoid obstruction of the building equipment. The CFT structure with the improved concrete filling showed the same structural behavior as the CFT structure with the use of the same type of diaphragms at the upper and lower connections.

Simulation of Piezoelectric Dome-Shaped-Diaphragm Acoustic Transducers

  • Han, Cheol-Hyun;Kim, Eun-Sok
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.5 no.1
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    • pp.17-23
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    • 2005
  • This paper describes the simulation of a micromachined dome-shaped-diaphragm acoustic transducer built on a $1.5{\mu}m$ thick silicon nitride diaphragm ($2,000{\mu}m$ in radius, with a circular clamped boundary on a silicon substrate) with electrodes and piezoelectric ZnO film in a silicon substrate. Finite element analysis with ANSYS 5.6 has been performed to analyze the static and dynamic behaviors of the transducer under both pressure and voltage loadings.

정수압 저어널 베어링의 동특성 향상에 관한 연구

  • 양문호;이기영;안유민;한동철
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1996.10a
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    • pp.195-201
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    • 1996
  • The dynamic characteristics of externally pressurized journal bearing have been studied theoretically. The Reynolds' equation has been solved by FDM, and the dynamic coefficients have been calculated by using perturbation method. The bearing is compensated by orifice or double-pad diaphragm control valve. The effects of diaphragm initial gap and stiffness are considered. As the results of analysis, it is shown that a control valve has better performance than orifice.

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CFT seismic reinforcement method using diaphragm pre-assembled ㄷ-shaped column (다이어프램 선 조립 ㄷ형태 기둥을 이용한 CFT내진보강공법)

  • Woo, Jong-Yeol;Shin, Seung-Hun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2022.11a
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    • pp.151-152
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    • 2022
  • When reinforcing an existing building with the Concrete Filled Tube(CFT) structure, it is impossible to form a diaphragm inside with the existing method. Therefore, in this study, a construction method was proposed so that the internal diaphragm could be welded on four sides by using a slot to transmit force.

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The Charateristics of Glycogen Metabolism of Diaphragm in Rats (운동부하시 흰쥐 호흡근의 당원 대사)

  • Nam, Bok-Hyun;Kim, Eun-Jung;Lee, Suck-Kang
    • Journal of Yeungnam Medical Science
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    • v.14 no.1
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    • pp.46-52
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    • 1997
  • Diaphragm is thought to play the most important role in breathing and has a substantially greater proportion of slow oxidative and fast glycolytic fibers, and low proportion of fast oxidative fibers. The respiratory muscle, diaphragm, has the functional characteristics of slow speed of contraction, high resistance to fatigue and the ability to respond to intermittent ventilatory loads, for example of exercise. In the present study, the characteristics of the metabolism (depletion and repletion) of glycogen and the structural changes of diaphragm during depletion and repletion of glycogen were observed in rats. For comparison, the red gastrocnemius muscle which has a greater proportion of fast oxidative glycolytic (FOG) and slow oxidative (SO) fibers, and low proportion of fast glycolytic (FG) fiber, was also studied. The glycogen concentration of diaphragm in overnight fasted rats was $2.30{\pm}0.14mg/gm$ wet weight. The values of glycogen concentration at 60, 90 and 120minutes of treadmill exercise loaded rats was significantly decreased compared to that of the overnight fasted rats. There was no significant difference among the glycogen concentrations of diaphragm at 60, 90 and 120minutes of exercises. The glycogen concentration of diaphragm was decreased to $1.12{\pm}0.17$ from $2.30{\pm}0.14mg/gm$ wet weight by treadmill exercise. The glycogen depletion rate of diaphragm during exercise was faster than that of red gastrocnemius in both of the first 60minutes and 120minutes duration of exercise. The glycogen repletion of diaphragm after intragastric glucose administration by stomach tube was studied in control and exercise groups. The glycogen concentration was significantly increased after glucose administration in both of control and exercise groups. All of the concentration of exercise group at 60, 120 and 180minutes after glucose administration was significantly higher than those of control group. In conclusion, one of the characteries of diaphragm in glycogen metabolism is fast glycogen depletion during exercise, and slowness of glycogen repletion after glucose ingestion in rats.

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