• Title/Summary/Keyword: Discharge Pressure

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Structural Analysis of the Valve Block of a Swash Plate-Type Axial Piston Pump (사판식 축 피스톤 펌프 밸브블록의 구조 해석에 관한 연구)

  • Kim, Jeong-Hwa
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.15 no.3
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    • pp.52-57
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    • 2016
  • A swash plate-type piston pump is a device used to discharge hydraulic fluid as the volume generated through the piston moves in the direction of the slope by adjusting the angle of its swash plate. In addition, the valve block internalized in the pump includes a flow path for intake from outside, a flow path for discharge, and a pilot conduit line to control discharge pressure and flux. In this study, a numerical analysis is conducted to improve the cracking of the valve block generated during process testing, and the developed pump is evaluated.

An Analysis on the Discharge Characteristics through 1-D Numerical Simulation in an AC PDP (AC PDP에서 1차원 수치해석을 통한 방전 특성 연구)

  • Lee, J.H.;Seo, J.H.;Lee, S.H.
    • Proceedings of the KIEE Conference
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    • 2003.10a
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    • pp.220-222
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    • 2003
  • In this paper, we analyze on the discharge characteristics through 1-D simulations in an at plasma display panel discharge cell. The model is based on a Poisson' equation, continuity and drift-diffusion equation. Results are presented in a 95% neon, 5% xenon gas mixture, for a gap length of 100us and a gas pressure of 400Torr at ambient temperature. Results for other gap length are also discussed. As a result, an increase of the gap cause increase of luminous efficiency but with larger sustaining voltage.

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Preparation of FeAl nanopowders by Plasma Arc Discharge Process (플라즈마 아크방전(PAD)법으로 제조된 FeAl 나노분말 특성)

  • Park Woo-Young;Youn Cheol-Su;Yu Ji-Hun;Oh Young-Woo;Choi Chul-Jin
    • Journal of Powder Materials
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    • v.11 no.6 s.47
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    • pp.522-527
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    • 2004
  • Nano sized FeAl intermetallic particles were successfully synthesized by plasma arc discharge pro-cess. The synthesized powders shouted core-shell structures with the particle size of 10-20 nm. The core was metallic FeAl and shell was composed of amorphous $AI_{2}O_{3}\;and\;a\;little\;amount\;of\;metallic\;Fe_{3}O_{4}.$ Because of the difference of Fe and Al vapor pressure during synthesis, the Al contents in the nanoparticles depended on the Al contents of master alloy.

Effect of the Process Parameters on the Fe Nano Powder Formation in the Plasma Arc Discharge Process (플라즈마 아크 방전법에서 Fe 나노 분말 형성에 미치는 공정변수의 영향)

  • 이길근;김성규
    • Journal of Powder Materials
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    • v.10 no.1
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    • pp.51-56
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    • 2003
  • To investigate the effect of the parameters of the plasma arc discharge process on the particle formation and particle characteristics of the iron nano powder, the chamber pressure, input current and the hydrogen volume fraction in the powder synthesis atmosphere were changed. The particle size and phase structure of the synthesized iron powder were studied using the FE-SEM, FE-TEM and XRD. The synthesized iron powder particle had a core-shell structure composed of the crystalline $\alpha$-Fe in the core and the crystalline $Fe_3O_4$ in the shell. The powder generation rate and particle size mainly depended on the hydrogen volume fraction in the powder synthesis atmosphere. The particle size increased simultaneously with increasing the hydrogen volume fraction from 10% to 50%, and it ranged from about 45nm to 130 nm.

Effects of Injector Shape Variation on Combustion Performance of a Subscale Gas Generator (분사기 형상 변화에 따른 축소형 가스발생기 연소 특성)

  • Kim, Mun-Ki;Lim, Byoung-Jik;Kang, Dong-Hyuk;Ahn, Kyu-Bok;Kim, Jong-Gyu;Choi, Hwan-Seok
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.11a
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    • pp.159-162
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    • 2011
  • The hot-firing tests of a subscale gas generator were successfully performed to investigate the effect of injector shape variation on its discharge coefficient. The test results showed that discharge coefficients of fuel and liquid oxygen injectors remained nearly constant irrespective of the mixture ratio or the chamber pressure. In all experimental conditions, the combustion instability was not observed.

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Electrical Properties of Plasma Polymerized Hexamethyldisiloxane Thin Film (플라즈마 중합법에 의한 헥사메틸디실록산 박막의 전기적 특성)

  • 이상희;이덕출
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.1
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    • pp.43-47
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    • 2001
  • Plasma polymerized hexamethyldisiloxane thin film was fabricated by employing an inter-electrode capacitively coupled type apparatus under the following conditions : carrier gas flow rate of 11 sccm, reaction pressure of 0.1 torr, discharge frequency of 13.56 MHz and discharge power of 30∼90 W. Polymerization rate of thin film fabricated at the discharge power of 90W is 32.5nm/min. Relative dielectric constant and dielectric loss tangent of thin film shows 3.2∼3.8 and 2.6x10$\^$-3/∼4.51x10$\^$-3/ respectively in the frequency range of 1 kHz∼1 MHz. As the annealing temperature is increased, the relative dielectric constant gradually decreases while the dielectric loss tangent increases. The current density increase gradually with increasing annealing temperature and electric field. The electric conduction of the heaxamethyldisiloxane thin film shows Schottky effect.

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Fabrication and Characterization of Electrical Discharge Machinable $Si_3N_4$-TiN Composites

  • Park, Heon-Jin;Kim, Young-Wook;Lee, June-Gunn;Lee, Soo W.;Chung, Soon-Kil
    • The Korean Journal of Ceramics
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    • v.1 no.2
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    • pp.101-105
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    • 1995
  • Electrical discharge machinable $Si_3N_4$ was fabricated with the addtion of 20-60 vol% TiN by gas pressure sintering. Their sinterability, microstructure, mechanical and electrical properties were characterized as a function of the TiN content. The addition of TiN up to 20 vol% increased the flexural strength and fracture toughness as compared with those of the monolithic Si3N4. For the TiN content higher than 40 vol%, the electrical resistivity was lower than $1062\Omega$.cm. The $Si_3N_4$ with the addition of 40 vol% of TiN appears to have the optimum considerable sinterability, mechanical and electrical properties, and machinability. A microstructural analysis showed that the enhanced toughening was due to the crack deflection.

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Dry Etch Process Development for TFT-LCD Fabrication Using an Atmospheric Dielectric Barrier Discharge

  • Choi, Shin-Il;Kim, Sang-Gab;Choi, Seung-Ha;Kim, Shi-Yul;Kim, Sang-Soo;Lee, Seung-Hun;Kwon, Ho-Cheol;Kim, Gon-Ho
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.1272-1275
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    • 2008
  • We present the development of dry etch process for the liquid crystal display (LCD) fabrication using a dielectric barrier discharge (DBD) system at atmospheric pressure. In this experimental work, the dry etch characteristics and the electrical properties of thin film transistor are evaluated by using the scanning electron microscopy and electric probe, and TFT-LCD panel ($300\;mm\;{\times}\;400\;mm$) is manufactured with the application of the amorphous silicon etch step in the 4 mask and 5 mask processes.

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A Study on the Dielectric Breakdown Strength and Transparency of Dielectric Layer on the Discharge Electrodes in PDP (PDP에서 방전전극상의 유전층의 절연내력과 투명도에 관한 연구)

  • Lee, Sung-Hyun;Kim, Young-Kee;Chi, Sung-Won;Cho, Jung-Soo;Park, Chung-Hoo
    • Proceedings of the KIEE Conference
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    • 1997.11a
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    • pp.379-381
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    • 1997
  • The dielectric layers in AC plasma display panel(AC PDP) are essential to the discharge cell structure, because they protect metal electrodes from sputtering by positive ion and from a sheath of wall charges which are essential to memory function of AC PDP. Furthermore, this layer should be transparent because the visible light must pass through the layer. In this paper, the dielectric breakdown strength and transparency of the dielectric layer on the discharge electrodes are studied. The variables in this test are the dielectric layer thickness, dielectric firing condition, gas pressure, species of gas and so on.

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A study on the cyclic variability as a function of ignition energy in spark ignition engines (스파크 점화기관의 점화에너지 변화와 연소 변동과의 관계에 관한 연구)

  • Han, Seong-Bin
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.12
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    • pp.1647-1655
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    • 1997
  • The cyclic variations can be characterized by the variations in different type of parameters. These parameters may be grouped into four main categories: pressure-related parameters, combustion-related parameters, flame front-related parameters, and exhaust gas-related parameters. One of the resultant effects of the cycle-by-cycle variation in the combustion process, which is the most important with regard to the engine performance characteristics, is the cycle-by-cycle variation in IMEP. This paper uses the repetitive discharge igniter, which can change the ignition energy easily, to study on idle stability in a spark ignition engine. From this device, the 6 number of spark and 0.20 ms spark interval, it is very available for the idle stability.