• Korean Journal of Radiology
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• v.25 no.2
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• pp.210-211
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• 2024

• International Journal of Aeronautical and Space Sciences
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• v.11 no.1
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• pp.26-30
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• 2010

The present paper studies the thermally-induced vibration phenomenon of the flexible space boom structure. In order to simulate the thermally-induced vibration phenomenon of the flexible thin boom structure of the spacecraft with the attached tip mass in space, the thermally-induced vibration including thermal flutter is experimentally investigated at various thermal environments using a heating lamp in vacuum chamber. In this experimental study, fluctuating characteristics, natural frequency and thermal strains of the thermally-induced vibration are parametrically investigated at various thermal environment conditions. Finally the thermally-induced vibration of the flexible boom structure of the orbiting earth satellite in solar radiation environment from the earth eclipse region including umbra and penumbra is simulated using the power control of the heating lamp in the vacuum chamber.

• Proceedings of the KSMRM Conference
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• 1996.10a
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• pp.67-67
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• 1996

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.151.1-151.1
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• 2016

Complex oxide heterointerfaces have been extensively explored in the past due to the novel phenomenon emerging at such interfaces that differ from their individual bulk counterparts. The integration of a ferromagnetic (FM) material with the superconducting (SC) material leading to proximity effect is one of the commonly studied phenomenon in these heterostructures. In continuation, we have stabilized the FM layer La0.7Ca0.3MnO3 (LCMO) on SC material YBa2Cu3O7-${\delta}$ (YBCO) using pulsed laser deposition technique and explored the structural, magnetic, electrical and magneto-transport properties of this heterostructure. ${\Phi}$-scan measurements confirm the epitaxial nature of LCMO/YBCO heterostructure grown on single crystalline SrTiO3 substrate. The FM transition of LCMO and SC transition of YBCO are observed in the magnetization measurements of the bilayer structure. Through electrical measurements, we understood that the proximity effect leads to lowering of the SC transition of YBCO. The role of interface in the bilayer structure is also realized through electrical transport measurements.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.162.1-162.1
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• 2010

Cavitation phenomenon has long been a difficult problem that regarded as negative event to fluid machines or industrial facilities. In the latest, however, some engineers became to understand the power of cavitation and use it to cleaning wall after developing cavitation nozzle. In this paper, we introduce new concept for power-generation system using cavitation jet flow maid by nozzle and impulse turbine in vacuum condition. The vacuum needed to make cavitation is generated naturally by Torricelli's vacuum, 10.23m effective head drop without additional power. We analyzed water's boiling and the steam's mean free path according to vacuum purity levels for nozzles and turbine blades. The nozzles make water accelerate in the neck and boil in expansion section of the nozzles. The shape of the impulse turbine is designed for absorption of the molecule's kinetic energy of the steam.

• Journal of the Korean Professional Engineers Association
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• v.30 no.3
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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.

• Journal of the Semiconductor & Display Technology
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• v.10 no.4
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• pp.101-106
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• 2011

There are various methods in the flat panel display manufacture. The cost reduction effect is very big in case of using the screen printing method. The screen printing method is much used in the process of forming PDP barrier and can apply to the process of arranging the pillars for maintaining the vacuum gap of the vacuum glazing panel. The pillar which is one of the core elements for comprising vacuum glazing maintains the vacuum gap overcoming the vacuum pressure difference with the atmospheric pressure generated in vacuum glazing. At the same time, the deformation phenomenon by vacuum pressure is relived. In this paper, by using FEM about three considered in the pillar design and arrangement kinds of limiting factors, the simulation was performed. The pillar optimum arrangement method at within the maximum allowable tensile stress and heat transfer coefficients according to the arrangement try to be presented based upon the analyzed result data review and this validity tries to be verified by FEM.

• Vacuum Magazine
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• v.5 no.1
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• pp.9-12
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• 2018

Electronic nose has been developed for detection of various hazardous molecules, especially vapor organic compounds (VOCs), by adsorption and desorption phenomenon. However, although conventional electronic noses have provided many advantages such as simple detection and high sensitivity, they still need advanced technologies for selective specificity in real samples. In this review, we provide bionanoelectronic noses with natural receptors for selective odorant detection. This review includes from fabrication of natural receptors and conducting nanomaterials to bioelectronic noses. We also discussed their perspective applications for the future at the conclusion.

• Journal of the Korean Vacuum Society
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• v.4 no.3
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• pp.287-292
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• 1995

단결정 실리콘에 P,B,As 등의 dopant를 이온주입시켰을 때 상부에 스퍼터된 Ti과 고상반응에 의해 형성된 Ti 실리사이드막에 발생되는 blister 현상에 대해 조사했다. Dopant에 관계없이 dose양이 많을수록 Ti 실리사이드막에서 blister의 크기와 밀도가 증가한다. 실리콘 표면에 dopant를 주입한 후 열처리를 하여 damage를 줄여줌으로써 blister의 양을 줄일수 있었다. 이 때 열처리온도가 높을수록 blister의 수가 감소한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.3
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• pp.183-188
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• 2003

Non-molding and welding line happen by the assembly of gas at the connector terminal. There is not good phenomenon of burr by increasing the over injection pressure, the temperatures of die and resin to prevent from them. Therefore, the connector mold to apply the vacuum molding system is developed in this study. The vacuum pressure is controlled systematically with the optimum conditions in the important ingredients of injection molding that are the temperatures of melting resin and die and cooling condition. The badness in charging is cleared by making a vacuum to non-charging part of the deep bottom part of each cavity. And the vacuum system to reduce the cycle time is applied as the study envelopment of molding work. So, the good product and the productivity improvement can be obtained in this study.