• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.355-358
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• 2003

This paper presents characteristics of vacuum preloaded porous air bearing. Pressure distribution of a porous pad and vacuum pocket are calculated. And load capacity and stiffness of the bearing are analyzed with various vacuum parameters, that is. clearance height. tube diameter, tube length. pumping speed of vacuum pump, vacuum pocket to porous pad area ratio. From the simulation results, optimum clearance for best performance can be selected adjusting these parameters, especially tube diameter which is the most dominant source.

• 한국철도학회논문집
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• 제13권5호
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• pp.516-520
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• 2010

튜브 구조물의 압력을 대기압 이하로 유지하는데에 사용될 진공 펌프의 용량을 설정하기 위한 파라메타 연구를 수행하였다. 최근 철도 기술 연구자들은 초고속 수송 시스템의 하나인 튜브 열차 시스템에 관심을 가지게 되었다. 초고속을 달성하기 위하여 튜브 내부를 저압으로 유지할 필요가 있는데, 저압에서는 공기 저항이 극단적으로 줄어들기 때문이다. 진공 펌프 시스템은 튜브 내부를 저압으로 만들고, 누설을 보충하는 역할을 한다. 일련의 연구결과, 다양한 파라메타에 대한 진공 펌프의 용량을 구하였다. 이 결과들은 공기 저항 저감 효과를 분석하는데에 적용될 것이다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1329-1334
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• 2004

The most compact and convenient pulse tube cryocooler for practical applications is the coaxial type. It can replace Stirling cryocooler without any change to the Dewar or the connection to the cooled devices. The experimental results of the coaxial inertance tube pulse tube cryocooler for cooling superconductor RF filter are presented in this paper. To find optimal conditions of inertance tube pulse tube cryocooler, no load temperature according to the variations of inertance tube volume, reservoir volume are measured, and the cool down characteristics at the particular conditions are presented. In case of the coaxial type inertance tube pulse tube refrigerator, cool down time is the lowest in the inertance tube diameter of 1.3 mm and inertance tube length of 1900 mm and lowest temperature is 112K. This results are not satisfactory for practical applications. So, We propose vacuum insulation between regenerator and pulse tube in the Stirling type coaxial pulse tube cryocooler. Stirling type coaxial pulse tube cryocooler with the vacuum insulation between regenerator and pulse tube was designed and manufactured by KIMM(Korea Institute of Machinery and Materials). The optimal conditions will be tested for Stirling type coaxial pulse tube cryocooler with the vacuum insulation between regenerator and pulse tube.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.43-43
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• 1999

Cold Cathode 및 Pirani Gauge Tube를 시험 제작하고 그 특성들을 조사하였다. 제작된 Cold Cathode Tube의 특성을 조사하기 위해 진공도에 따른 Anode 전압 및 방전 전류의 변화를 측정하였는데 기존의 제품들의 결과들과 비교.분석하여 개선 가능성을 제시하였다. 또한 20$\mu\textrm{m}$ 굵기의 백금선을 filament로 하는 Pirani gauge Tube를 제작하여 진공도에 따른 저항의 변화를 측정하였고 그 결과를 기존의 제품들의 결과와 비교하였다. 특히 본 연구에서는 시험 제작된 Cold Cathode 및 Pirani gauge Tube의 시험 결과를 토대로 국내 개발의 가능성을 논의하고 Gauge Controller의 설계방향 등을 제시할 것이다.

• Applied Science and Convergence Technology
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• 제26권6호
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• pp.195-200
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• 2017

A mobile lab kart for plasma training is developed with a high vacuum pumping system, vacuum gauges and a glass discharge tube powered by a high voltage transformer connected to a household 60 Hz line. A numerical model is developed by using a commercial multiphysics software package, CFD-ACE+ to analyze the experimental data. Simulations for argon and nitrogen were carried out to provide fundamental discharge characteristics. Variations of the kart configuration were demonstrated: a glass tube with three electric probes, optical emission spectrometer attachment and infra red thermal imaging system to give more detailed analysis of the discharge characteristics.

• 한국진공학회지
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• 제19권3호
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• pp.161-168
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• 2010

진공펌프의 배기성능 지표들을 정량적으로 측정하기 위해서 사용하는 표준용기에 관한 ISO 규격은 기체도입 도관의 굵기를 용기 내경의 10분의 1로 규정하고 있다. 표준용기 내경은 검사 대상 펌프의 흡기구 직경보다 작아서는 안 되므로 만일 대용량 펌프에 맞춘다면 때에 따라 도관의 굵기가 100 mm라는 수치도 나올 수 있다. 전체 시스템의 크기가 커지는 만큼 이런 굵기의 도관도 수용이 가능하기는 하지만 과연 이렇게 굵은 도관이 정밀한 측정을 위해 꼭 필요한지 또는 오히려 방해가 되는 것은 아닌지 검토해 볼 필요성이 있다. 본 논문에서는 도관 굵기에 따라, 도관출구를 빠져나오는 입자들과 오리피스 및 펌프 흡기구에 입사하는 입자들의 등방성에 대해 살펴봄으로써 적절한 도관 굵기가 존재하는지에 대해 논의한다.

• 한국기계가공학회지
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• 제12권5호
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• pp.149-156
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• 2013

The performances of solar collectors with single and double evacuated tube were experimentally compared. The solar collector with single evacuated tube using surface treatment in this study consists of radiation fin, heat pipe, absorber plate, glass tube, cap and regulating valve, and so on. Surface treatment was conducted for heat pipe and absorber plate with black chrome plating and copper black coating. As the results, the performance of solar collector with single evacuated tube using surface treatment showed good results compared that of double evacuated tube. Absorber plate played a positive role in performance and showed increase of about 28%. Further performance depends on vacuum degree and vacuum degree has to be considered economical efficiency in solar collector.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.1445-1446
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• 2010

• 한국태양에너지학회 논문집
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• 제28권3호
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• pp.67-73
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• 2008

This study has been carried out to investigate the effect of vacuum on the thermal performance of a nonglass evacuated tube. A series of measurements are made indoors to monitor the temperature change of the absorber plate contained in the evacuated tube under different conditions of vacuum and heat fluxes. Those temperatures measured at the thermal equilibrium could be used to assess the heat losses to the ambient in link with the steady operation of non-glass evacuated tubes for solar exploitation.

• 기술사
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• 제30권3호
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• pp.43-51
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• 1997

Vacuum tubes are electron tubes in which the motion of electrons are utilized. There are many kinds of vacuum tubes, e.g. diode tubes, triode tubes, pentodes. muti-tubes and etc. Generally accommodated in glass tube, its eletrodes can be seen easily from outside and it easy to understand. In 1884 Edison discovered a current flow in the vacuum tube. He could not, however, explain this phenomenon. This is called Edison effect. In 1904 Fleming developed the backup for the practical diode theory. The most important milestone in this early history of electronics came in 1906 when De Forest put a third electrode (a grid) into the above, and thus invented the triode tube. It is 90 years since the triode was invented by De Forest (as of 1996) and 100 years (centennial also as of 1996) since the specific electric change e/mo$_0$ ≒ 1.7589 ${\times}$ 1011 (C/kg) was confirmed by the English scientist Thomson in 1896. On the occasion of the 90th and 100th anniversary of these inventions and discovery, E would like to describe the rise and 1111 of the vacuum tubes and the current status of these tubes.