• Explosives and Blasting
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• v.28 no.2
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• pp.28-36
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• 2010

A study about economical blasting methods which can improve fragmentation and save explosive in blasting is in progress. One of the blasting methods is an air decking method making air layers in boreholes. However, it is difficult to apply this method to the boreholes filled with water. In this study, an underwater Air Tube was manufactured and tried to place it at a certain location in a water filled borehole. It was found that the application of underwater air tube in wet boreholes could improve the fragmentation and save 10~15% of the explosives.

• Tunnel and Underground Space
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• v.17 no.4
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• pp.248-254
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• 2007

Already, the air deck blasting method has been used to take many advantages of blasting. In the existing air deck blasting method, air deck is made usually on column charge. But in the case study, we analyzed about the effect of self supporting air tube which made air deck in column charge. As results of this case study, it was shown that blasting vibration was decreased about $20{\sim}26%$ and quantity of explosive was decreased about $10{\sim}20%$. Also, fragmentation was shown to be smaller than it of common blasting method.

• 지반과기술
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• v.4 no.2
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• pp.85-90
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• 2007

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.4944-4949
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• 2012

The purpose of this paper is concerned with a development of air gun for use at work. A air gun is the tool to remove of cutting fluid and workpiece chip in industrial field used machine tool. And it generally is used to shoot a jet of compressed air. Worker must prepare respectively air gun for suction and shooting a jet of compressed air. Therefore we has developed new air gun. In this paper we research for design and analysis of it. The air gun is composed of body, pipe, opening and shutting unit, turning unit, air tube and elements for fabrication. The developed air gun is experimented to confirm the efficiency.

• Analytical Science and Technology
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• v.13 no.4
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• pp.412-422
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• 2000

The polymeric FAB materials of air shower used in clean room of wafer industry have been outgassed with the dynamic headspace (ca.$100^{\circ}C$) for half an hour, and analyzed using GC-MS. The air in the clean room running air shower was sampled using sorbent tube method, and the organic compounds adsorbed in the sorbent tube were extracted using Soxhlet extraction method, and analyzed using GC-MS. The analytical results from FAB materials of air shower (electric over current relay, acryl plate. polycarbonate window, filter, fan housing, steel galvanized cold plate and canvas buffer) indicated that most of chemicals were originated from polymer fragments of FAB materials. Their analytical results have been compared with those from the air of clean room running air shower. These comparative results could lead to identify whether the sources of trace organic contaminants in clean room air are originated from the polymeric FAB material of air shower.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1398-1402
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• 2015

In surface mount technology, the use of technology implemented using a Chip Mounter relay that is inserted into the junction box, etc. car is increasing. On the other hand, there is a need for technology to reduce the weight of the heavy component of the relay attached to different Stick Tube generally chips. Therefore, rather than existing technology, this study improved the algorithm of the system to provide a mechanical structure using Air to supply greater stability using this the component feeder utilizing the Stick Tube proposed technology. When the equipment installed in the Air Stick Feeder was used, the effectiveness, such as increased production and reduced disposal expense, was improved.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.29 no.10
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• pp.47-51
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• 2000

최근 룸에어콘이나 패키지에어콘의 에너지 절약, 쾌척성 등에 대환 사용자나 회사로부터의 요구는 더더욱 높아지고 있다. 공조기의 중요한 구성요소 중 하나인 열교환기도 이러한 요구에 대응하여 기술개발이 계속해서 진행되고 있다. 공조용 열교환기를 설계할 때 가장 중요한 과체는 비용이냐 설치성 등의 제약조건올 만족하면서 필요한 교환열량을 달성하기 위해, 요구되는 열 전달계수(K)와 전열면적(A)의 곱인 KA값을 얼마나 확보하는가 하는 점에 있다. 그러나 이 외의 과제, 예를 들어 홴입력, 소음을 억제하기 위한 공기측 통풍저항의 감소, 증발온도에 영향을 마치는 관내압력손실의 감소 등도 중요한 과제이다. KA값 증대와 통풍저항억제를 동시에 판촉하기 위해 공조용 열교환기는 전면면적을 크게 하고 두께를 작게 하여 사용하는 것이 원칙이다. 또, 전열관의 관경도 관 둘레길이와 냉매분배성능 면에서 제약이 발생한다. 이와 같은 배경으로부터 공조용 열교환기는 판경 6~10 mm정도의 전열 관을 20~25mm길이로 배치한 핀튜브형 열교환기가 주류로 되어있다. 여기에서는 공조기에 널리 사용하고 있는 핀튜브형 열교환기에 대한 최근의 기술개발 사례를 소개하고자 한다.

• Explosives and Blasting
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• v.21 no.2
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• pp.31-42
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• 2003

본 연구는 일반건설현장에서와는 달리 천공경이 $97mm{\Phi}$이상이고 천공장이 21M이상인 상태에서 발파작업이 진행되고 있는 석회석 광산에서 기존의 발파공법과 Air tubes를 이용한 발파공법을 비교하여 기존의 발파로 인한 상부 대괴를 감소시키고 폭약의 사용량을 줄이면서 진동 및 폭음을 최소화하여 보다 경제적인 작업수행을 하기 위해 연구하였다. 한편 에어층(Air deck)을 형성으로 인한 전색장의 길이 감소를 보완하기 위해 라바플러그(Rubber Plug)를 사용하므로 비석의 위험을 최소화 시키고 가스압이 암전체에 충분히 전달할 수 있도록 장치를 만들어 실험하였다. 그 결과 일반발파와 Air tubes를 이용한 발파방법을 비교하여 볼 때 Air tubes를 이용한 발파방법이 폭약을 약 15~30% 절감 할 수 있었으며, 또한 진동은 최대 50%정도의 감소와 폭음에서는 2~5dB 정도로 감소되었다.

• Tunnel and Underground Space
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• v.16 no.2 s.61
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• pp.156-165
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• 2006

Already, vari-stem, gas-bag, power deck, air ball etc. are used by various blasting methods to take the advantage of air decking technology in abroad. Air tube product has been used continuously in domestic and air ball product was made recently. In the case study, we analyzed about the application and the effect or air deck blasting method in domestic blasting area. As results or this case study, it was shown that blasting vibration was decreased about $21{\sim}41%$ and quantities or explosives was decreased about $17{\sim}30%$. Also, in the case of using air deck blasting method, fragmentation was shown to be smaller than common blasting method.

• Korean Chemical Engineering Research
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• v.52 no.3
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• pp.335-339
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• 2014

The studies on the characteristics of composite of silica aerogel and pulps were carried out. The composite was manufactured by mixing the paste of silica aerogel and pulps and analyzed by SEM. Using the impedence tube, the sound absorption measurement was investigated. The maximum value of sound absorption coefficient of this composite was obtained in the range of 900 Hz. It was found that the composite of silica aerogel and pulps could be a new sound absorbent because of high absorption capacity and durability which was due to hydrophobic effect on the surface of the composite.