• Tribology and Lubricants
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• v.12 no.3
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• pp.26-32
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• 1996

오랜 역사에 걸쳐 연구자들은, 마찰력은 주로 접착에 의한 것으로 믿어 왔으며, 이러한 주장은 실험적으로 증명되지 못했다. 한편, 미끄럼 두 표면 사이의 건식 마찰력은 두 표면 사이의 기계적인 상호작용에 의한 것으로 알려져 있다. 이 연구에서는 두 표면 사이의 기계적 상호작용을 제거함으로써 마찰계수를 감소시키는 방법을 제시하였다. 매끄러운 경한 표면에 얇은 elastomer층을 입힌 비윤활 최소 마찰계수에 대한 본 실험결과는 앞으로 정밀기계부품의 충격을 받는 부위에 응용할 수 있을 것으로 기대된다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.4
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• pp.330-334
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• 2007

The objective of this study was to investigate the effecs of fouling mitigation for ceramic ball in cooling water system experimentally. The devices filled with ceramic balls were connected to the bypass line of the heat exchanging system. Cooling water in the heat exchanging system was artificial water. To visualize the formation of fouling on the heat transfer surface a number of images were obtained using a CCD camera with real-time microscopy. Fouling resistances and overall heat transfer coefficients were measured in order to analyze fouling mitigation effects. We found that the ceramic ball devices for artificial water reduced the formation of fouling compared to the no-mitigation devices.

• Journal of Acupuncture Research
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• v.23 no.6
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• pp.199-205
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• 2006

Objectives : The present study was conducted to evaluate the analgesic effects of automatically controlled heating acupuncture(ACHA) using 2 different pain models(acute pain and neuropathic pain) and 2 different stimulation conditions (heating $41.5^{\cdot}C$ and heating $44.5^{\cdot}C$) in Sprague-Dawley rats. Methods : Tail flick latency(TFL) to a noxious radiant heat stimulus in lightly anesthetized rats was measured before and after ACHA stimulation for 5-min at the Zusanli(ST36) acupoint. For the neuropathic surgery, the right superior caudal trunk was resected at the level between S1 and S2 spinal nerves innervating the tail. Two weeks after the nerve injury, ACHA stimulation($41.5^{\cdot}C$ or $44.5^{\cdot}C$) was delivered to Zusanli(ST36) for 5 min. The behavioral signs of warm allodynia were evaluated by the tail immersion test (i.e. immersing the tail in warm $water(40^{\cdot}C)$ and measuring the latency to an abrupt tail movement) before and after the ACHA stimulation. Results : In the TFL test, ACHA stimulations under both the conditions above produced more potent analgesic effects than plain acupuncture(PA, acupuncture needle insertion only) and control(no treatment). In the tail immersion test, ACHA stimulations under all of the conditions had markedly relieved the warm allodynia signs. Conclusion : Automatically controlled heating acupul1cture produced analgesic effecs in acute and neuropathic pains.