• Title/Summary/Keyword: Vacuum characteristics

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ICCD Observation on Discharge Characteristics of 42-in. AC Plasma Display Panel Fabricated by Vacuum Sealing Method

  • Park, Choon-Sang;Tae, Heung-Sik;Kwon, Young-Kuk;Heo, Eun-Gi;Lee, Byung-Hak
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.320-323
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    • 2007
  • The vacuum sealing method is adopted to minimize the residual impurity gas by enhancing a base vacuum level, and the resultant changes in the reset, address, and sustain discharge characteristics, such as a firing voltage, IR emission, and ICCD image, were examined in comparison with the conventional sealing method in the 42-in. AC-PDP. In the PDP cells fabricated by the vacuum sealing method, the ICCD observation illustrates that the discharge is initiated and extinguished very fast and its IR emission intensity is high.

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Development of VCB Driving Mechanism using Permanent Magnetic Actuator (자기 액츄에이터를 이용한 진공차단기 구동 메카니즘 개발)

  • 최명준;석복렬;김창욱;최영찬;박일한
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.52 no.8
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    • pp.381-389
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    • 2003
  • Nowadays, Vacuum Circuit Breaker(VCB) is used in the most medium voltage level because vacuum has environment-friendly characteristics as well as excellent dielectric strength. In order to elevate the breaking performance, the improvement of vacuum interrupters and the driving mechanism should be proceeded. In this paper, the development of a Permanent Magnet Actuator could replace the mechanical spring mechanism which is the driving mechanism of existing VCB. The holding force and opening characteristics of magnetic actuator are analysed with FEM and the result is verified through experiment.

Resistive Switching Characteristics of Amorphous GeSe ReRAM without Metalic Filaments Conduction

  • Nam, Gi-Hyeon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.368.1-368.1
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    • 2014
  • We proposed amorphous GeSe-based ReRAM device of metal-insulator-metal (M-I-M) structure. The operation characteristics of memory device occured unipolar switching characteristics. By introducing the concepts of valance-alternation-pairs (VAPs) and chalcogen vacancies, the unipolar resistive switching operation had been explained. In addition, the current transport behavior were analyzed with space charge effect of VAPs, Schottky emission in metal/GeSe interface and P-F emission by GeSe bulk trap in mind. The GeSe ReRAM device of M-I-M structure indicated the stable memory switching characteristics. Furthermore, excellent stability, endurance and retention characteristics were also verified.

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Operating Characteristics of Low Vacuum Pumps (저진공 펌프의 운전 특성)

  • 임종연;심우건;정광화
    • Journal of the Korean Vacuum Society
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    • v.12 no.2
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    • pp.93-104
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    • 2003
  • For evaluation of durability of low vacuum pumps, it is required to examine the performance and degradation of low vacuum pumps. Pump degradation may result from abnormalities associated with the performance in many areas of pump operation. The diagnostics method can be used to monitor the pump performance in the semi-conductor process line. Based on the mechanical defect of the pump, the dynamic response and reliability of the system for performance test, and the dynamic characteristics of the pump were experimentally assessed. The theoretical work rate for the compression process in the pump was calculated, and then the efficiency of the pump associated with the power consumption was evaluated. This analysis will be useful in detecting pump degradation with increasing the power consumption. To determine the predominant factors of pump degradation, it is important to evaluate the entire pumping system. We studied vibration, dynamic pressure, pumping speed, and power consumption of low vacuum pumps. Our results can be utilized for the future research on the evaluating technology of durability of low vacuum pumps.

Quality Characteristics of Vacuum-Dried Gulbi Based on Temperature and Time (온도와 시간에 따른 진공건조 굴비의 품질특성)

  • Park, Hyun Su;Hyun, Myung-Taek;Lee, Ju-Hee;Kim, Dae Young;Lee, Khan;Kim, Hyun Jung
    • Korean journal of food and cookery science
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    • v.33 no.3
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    • pp.316-324
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    • 2017
  • Purpose: Gulbi is a salted and dried yellow corvenia that is popular in Korea. In this study, yellow corvenia was vacuum-dried under two different conditions, average temperatures of $48^{\circ}C$ for 12 and 15 h and $54^{\circ}C$ for 9 and 12 h. Quality characteristics of vacuum-dried Gulbi against fresh corvenia were investigated. Methods: Moisture content, water activity, salt concentration, pH, acidity, volatile basic nitrogen (VBN), thiobarbituric acid-reactive substances (TBARS), and fatty acid composition of Gulbi were evaluated. Results: Moisture contents of fresh corvenia and four types of vacuum-dried Gulbi were 67.37, 31.51, 13.62, 35.17, and 10.05%, respectively. The pH values were in the range of pH 6.70-6.98. The VBN values of Gulbi vacuum-dried at the higher temperature range were greater than those of Gulbi at the lower temperature range. The TBARS of Gulbi increased after vacuum drying (p<0.05). Palmitic acid, palmitoleic acid, oleic acid, and docosahexaenoic acid were the main fatty acids of Gulbi. Conclusion: These results indicate that the quality of vacuum-dried Gulbi is dependent on the drying conditions including temperature and time.

A Study on the Characteristics of High-Current Arc Plasma Influenced by Axial Magnetic Field (축방향 자기장에 의한 대전류 아크 특성에 관한 연구)

  • Cho, S.H.;Lee, J.C.;Choi, M.J.;Kwon, J.R.;Kim, Y.J.
    • Proceedings of the KSME Conference
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    • 2008.11b
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    • pp.2515-2518
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    • 2008
  • The vacuum interrupter (VI) is widely used in medium-voltage switching circuits due to its abilities and advantages as an environmental friendly circuit breaker. An understanding of the vacuum arc flow phenomena is very important for improving the performance of vacuum interrupter. In order to closely examine the vacuum arc phenomena, it is necessary to predict the magnetohydrodynamic (MHD) characteristics by the multidisciplinary numerical modeling, which is coupled with the electromagnetic and the thermal flow fields, simultaneously. In this study, we have investigated arc plasma constriction phenomena and an effect of AMF on the arc plasma with the high-current vacuum arcs for the cup-type AMF electrode by using a commercial finite element analysis (FEA) package, ANSYS. The simulation results applied with various AMFs and constant Joule heat generation show that strong axial magnetic field (AMF) permits the arc to be maintained in a diffused mode to a high-current vacuum arc. However, further studies are required on the two-way coupling method and radiation model for arc plasma in order to accomplish the advanced analysis method.

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The Analysis of the Discharging Characteristics on the Base Vacuum Level in a Vacuum In-line Sealing Process for High-efficiency PDP (고효율 PDP 제작을 위한 진공 인라인 실장에서의 초기 진공도에 따른 방전특성 분석)

  • Kwon Sang Jik;Jang Chan-Kyu;Kim Yong-Jae
    • Journal of the Korean Vacuum Society
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    • v.15 no.1
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    • pp.57-63
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    • 2006
  • We have examined the electrical and optical characteristics of the plasma display panel(PDP) produced by vacuum in-line sealing technology. We found that the luminous efficiency was decreased as the base vacuum level was increased. For the base vacuum level of $1\times10^{-3}$ Torr, the firing voltage was 235V at the discharge gas pressure of 400 Torr and the luminous efficiency was 0.8 lm/W at 180V sustaining pulse. However, for the base vacuum level of $1\times10^{-6}$ Torr, the firing voltage was reduced to 215V and the luminous efficiency was improved to 2.5lm/w. Finally, we demonstrated successfully the operation of tip-less PDP fabricated using vacuum in-line sealing method.