• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.47-47
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• 2010

게이트 밸브는 진공 시스템 구성에 있어서 빠질 수 없는 중요한 부품 중 하나로 공간을 구획하여 필요에 따라 자유롭게 진공 상태와 대기 개방 상태가 공존하도록 만들어 주며 진공펌프와 같은 주요 기기들의 탈착 및 교체를 용이하게 해 준다. 게이트 밸브는 열린 상태에서는 저항이 최소화되는 반면 닫힌 상태에서는 마치 마구리 플랜지로 막은 것처럼 완벽한 차단이 요구된다. 일반적으로 게이트 밸브 상용제품은 개스킷이 닿는 밸브 시트가 한쪽에만 마련되어 있으므로 디스크 기계구조가 충분한 압력을 발휘하지 못한다면 어느 쪽이 대기압인가에 따라 디스크를 미는 힘의 크기가 변하여 기밀특성이 달라질 수 있다. 따라서 게이트 밸브의 누설검사는 순방향과 역방향 모두에 대해 시행해야 한다. 양방향 누설검사를 위해 한쪽 밸브 공간을 배기하고 반대쪽 공간에 헬륨을 뿌리는 작업을 교대로 하려면 배기시간의 단축과 신속한 잔류 헬륨기체 제거가 필수적이다. 게이트 밸브 제조 공장에서 상품을 출하하기 위한 시험검사라는 것을 전제로 합리적인 시간 내에 정확한 누설검사를 일관성 있게 할 수 있는 적절한 누설검사 시스템을 설계하고 측정절차를 상용 게이트 밸브에 대해 적용해 보았다.

• Journal of the Korean Vacuum Society
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• v.16 no.4
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• pp.235-243
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• 2007

Nowadays, in our country, large vacuum chambers for huge experimental facilities such as the tokamak fusion device, high power neural beam test stand, and space simulator have been constructed. In such a vacuum chamber of very large size, it is quite complicate to check on leakage quantitatively, while the probability of a leak is relatively high. To investigate the feasibility of applying reliably a helium leak detection to the huge vacuum chambers, and to find a reasonable methodology of choosing an optimum set-up for leak detection, several virtual constructions of the leak detection system have been analyzed by calculating the pressure distribution in the system and the helium level in the sensor part.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.2
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• pp.109-113
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• 2016

Pre-analytical variables account for most laboratory errors and many factors affect the results from a patient. Type of tubes facilitated rapid separation and prevented hemolysis upon prolonged storage. However, there were some limitations associated with vacutainer conditions. To circumvent the problems, the comparability of complete blood cell count values was examined using various vacutainers. The results of the analysis showed a large coefficient variation of 0.24, 0.21 in the value of white blood cells and platelets, and significant correlation was observed between white blood cells, platelets, and the value of red blood cells (p<0.01). In each of the three tubes, compared to the value of platelets, white blood cells, the greatest coefficient variation was 0.27, 0.21. In correlation of the three companies, significant difference was observed in values of white blood cells, platelets, and platelet distribution width (p<0.01), however G and B, the value of platelets, and platelet distribution width were significantly lower (p<0.05). In conclusion, analysis of vacutainers showed that they were suitable for stability of these analytes under vacutainer conditions.

• Journal of the Korean Society for Nondestructive Testing
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• v.13 no.3
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• pp.31-38
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• 1993

The storage ring vacuum system for the Pohang Light Source (PLS) has been designed to maintain the vacuum pressure of $10^{-10}Torr$ which requires UHV welding to have helium leak rate less than $1{\times}10^{-10}Torr{\cdot}{\ell}/sec$. In order to develop new technique (PLS) welding technique), a prototype vacuum chamber has been welded by using Tungsten Inert Gas welding method and all the welded joints have been tested with a non-destructive method, so called helium leak detection, to investigate the vacuum tightness of the weld joints. The test was performed with a detection limit of $1{\times}10^{-10}Torr{\cdot}{\ell}/sec$ for helium and no detectable leaks were found for all the welded joints. Thus the performance of welding technique is proven to meet the criteria of helium leak rate required in the PLS Storage Ring. Both the principle and the procedure for the helium leak detection are also discussed.

• Proceedings of the Korean Vacuum Society Conference
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• 2004.08a
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• pp.109-109
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• 2004

• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.557-563
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• 2004

A new vacuum assisted auto-lancing technique is proposed to minimize pain. Specially designed lancing device was introduced, which applied -100mmHg right after skin puncture on the forearm. Sampled blood volumes were measured in 58 normal females. Mean volume of 464 samples was approximately 2.6$\muL$ and the frequency of more than 0.5$\muL$ was 86%. Thus the success rate of blood sugar test should also be the same when using modern glucose meters capable of testing with only 0.3~0.5$\muL$ of capillary blood. When pain scores were quantitatively evaluated by the visual pain measure, only 23% pain of the traditional finger sampling was experienced, demonstrating that capillary blood sampling was performed on the forearm with almost no pain. The present technique reduced pain to a great degree, though resampling might be unavoidable due to 14% of test failure rate estimated for modern glucose meters. However, minimized pain makes the present technique of great convenience for diabetic patients who need blood sampling a few times a day.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2005.05a
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• pp.168-172
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• 2005

본 연구에서는 평판 디스플레이 Photo공정 중에서 무회전 도포(Spinless Coating)방식으로 기판(Glass)에 감광제 약액을 도포한 후 용매(Solvent)를 제거시키기 위한 진공건조장치(Vacuum dryer)에서 감광제 도포막의 품질에 영향을 주지 않는 범위 안에서의 용매 제거시간을 단축하기 위한 진공챔버의 용적에 따른 진공포트의 크기 및 배치에 대한 최적화를 구현하였다. 구현된 챔버의 용적과 진공포트의 크기 및 배치를 바탕으로 진공건조장치를 챔버, 챔버 구동부, 기판 구동부, 진공펌프, 그리고 $N_2$ 공급부로 모듈화하여 구성하였으며. 실제 도포 기판을 이용하여 진공건조를 실시한 후 도포막을 검사함으로써 진공포트에 대한 최적화를 검증함과 동시에 진공건조 능력을 확인하였다.

• Korean journal of food and cookery science
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• v.17 no.3
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• pp.204-210
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• 2001

Rice cakes were prepared by the addition of yellow soybean flour or peanut flour and packaged with $CO_2$-modified packaging(CMP) or vacuum packaging(VP), and their physical characteristics were monitored by sensory evaluation and mechanical measurement while storing for 6 days. For VP samples, yellow soybean rice cake showed little changes in cohesiveness, moistness and chewiness for 6 days of storage, while pure rice cake and peanut rice cake showed an increase in strength and hardness from the 4th day of storage. In case of CMP, yellow soybean rice cake hardly showed a difference in cohesiveness, moistness and chewiness for 6 days, while pure rice cake and peanut rice cake showed a significant difference from the 4th day in sensory evaluation. For rheometer measurement, yellow soybean rice cake with CMP or VP showed little changes in strength or hardness for 6 days, while peanut rice cake and pure rice cake showed a drastic decrease in cohesiveness from the 2nd day and adhesiveness from the 4th day of storage. As there was no remarkable difference or deterioration for 6 days of storage in yellow soybean rice cake between CMP and VP, the ingredients of rice cake appeared to be more important than the type of packaging in terms of the quality deterioration of rice cake.

• Journal of the Korean Society for Nondestructive Testing
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• v.14 no.3
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• pp.157-171
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• 1994

A scanning tunneling microscope has been built, which can resolve atomic arrangements of conductors and semiconductors in ultra high vacuum below $10^{-11}$ Torr. Its background and operational principles are reviewed and the guide lines in building the scanning tunneling microscope are shown. The results of measurements for highly oriented pyrolytic graphite and Si(111) surface are presented.

• Aerospace Engineering and Technology
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• v.6 no.2
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• pp.188-196
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• 2007

A composite case was designed to satisfy the required condition of KSLV-I kick motor system. we performed the structure and combustion tests to insure the reliability of the case before the production of the flight model. The hydraulic, vacuum and non destruction testes as the structure test were carried out to confirm the strength of the components of the case and the characteristics of the thermal and structure were investigated through the ground combustion test.