• 한국공작기계학회논문집
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• 제13권2호
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• pp.127-132
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• 2004

In industrially advanced countries, environmentally conscious machining was eagerly studied because of ecological and economical reasons. As the environmental regulations become stricter, the new machining technologies which take environmental aspects into consideration are being developed. Recently the research institutions have established application method for dry, semi-dry, oil-mist and compressed cold air machining. In this paper the performance of new compressed cold air system for environmentally conscious machining is investigated and machinability of dry and new compressed cold air machining is evaluated. A series of tests are carried out by using measuring equipments in condition of dry and compressed cold air machining.

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2001년도 추계학술대회(제116회) 및 13회 Workshop 제3회 한ㆍ일 치과보존학회 공동학술대회 초록집
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• pp.587.2-587
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• 2001

The purpose of this study is to evaluate influence of moisture control on bond strength of self-etching primer by measuring enamel and dentin shear bond strengths. 96 extracted human molars were divided into 8 groups. Group 1 (Enamel 30min Dry), Group 2 (E. 5s air dry), Group 3 (E. 1s air dry), Group 4 (E. blot dry), Group 5 (Dentin 30min Dry), Group 6 (D. 5s air dry), Group 7 (D. 1s air dry), Group 8 (D. blot dry) were divided.(omitted)

• 한국기계가공학회지
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• 제1권1호
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• pp.48-54
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• 2002

In industrially advanced countries, environmentally conscious machining was eagerly studied because of ecological and economical reasons. As the environmental regulations become stricter, new machining technologies which take environmental aspects into consideration are being developed Industry and research institutions established applications for dry, semi-dry, oil-mist and compressed cold air machining. This paper investigates the performance of new compressed cold air system for environmentally conscious machining and evaluates machinability of dry and new compressed cold air machining. A series of tests are carried out using measuring eqipments under dry and compressed cold air machining.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.1008-1011
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• 2002

In industrially advanced countries, environmentally conscious machining was eagerly studied because of ecological and economical reasons. As the environmental regulations become stricter, new machining technologies which takes environmental aspects into consideration are being developed. Industry and research institutions established applications for dry, semi-dry, oil-mist and compressed cold air machining. This paper investigates the performance of new compressed cold air system for environmentally conscious machining and evaluates machinability of dry and new compressed cold air machining. A series of tests are carried out using measuring equipments under dry and compressed cold air machining.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 Techno-Fair 및 합동춘계학술대회 논문집 전기물성,응용부문
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• pp.125-126
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• 2008

본 연구에서는 챔버 내에 압력 $1{\sim}7$[atm]의 Dry-Air를 주입한 후, AC전압을 인가하여, 전극의 모양에 따라 불평등 전계/준평등 전계를 형성하였을 시, 전극 사이에 넣은 고체절연물의 두께에 따른 연면방전 특성을 실험을 통하여 측정 비교한 것이다. 고체절연물로는 열경화성 플라스틱을 사용하였다. 챔버 내 Dry-Air의 주입압력이 높일수록 연면 절연파괴 전압이 높았고, 준평등 전계에서보다 불평등 전계 인가시 더 높은 절연파괴 저압을 얻을 수 있었다. 또한 고체절연물의 두께가 두꺼울수록 고체의 절연파괴 전압이 높았으며, 고체절연물의 두께가 2[mm]일 경우, Dry-Air의 연면방전 특성이 $SF_6$보다 평균적으로 $12{\sim}51$[%] 낮고, 3[mm]의 경우도 Dry-Air의 연면방전 특성이 $14{\sim}45$[%] 가량 낮았다.

• Journal of Electrical Engineering and Technology
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• 제10권3호
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• pp.1181-1187
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• 2015

Sulfur hexafluoride (SF₆) gas is used widely in electric power equipment such as Gas Insulated Switchgear (GIS), Gas Insulation transmission Line (GIL), and Gas Circuit Breaker (GCB). But applications of SF₆ should be restricted because SF6 gas is one of the greenhouse effect gases. To reduce use of SF₆ gas, a study on eco-friendly alternative insulation medium is needed. In this paper, we investigated lightning impulse (LI) breakdown of dry-air which is attracting attention as an ecofriendly alternative gas and the LI breakdown of hybrid insulation combined with dry-air and solid insulation (Room-Temperature Vulcanizing Silicone Rubber-RTV SIR) and dry-air in inhomogeneous fields according to gap distance and pressure. The experiment results showed that the LI breakdown strength of hybrid insulation system was higher than that of dry-air insulation system. It was verified that the development of technology related to eco-friendly power apparatus compact such GIS, GCB and GIL can be used as basic research data.

• 조명전기설비학회논문지
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• 제23권2호
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• pp.154-160
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• 2009

본 논문은 친환경 절연재료인 Dry-Air 중 에폭시 수지의 연면절연특성을 구명하여 Dry-Air를 절연매체로 사용한 각종 절연설계 시에 응용 가능한 기초자료를 제공하고자 한다. 사용한 전극은 침 대 평판, 구 대 평판, KS M3015 전극으로써, 동일한 조건 하에서 전극의 종류에 따른 연면 절연 파괴 전압, 연면 거리, 연면방전 전계강도를 비교하였다. 연면전계강도는 침 대 평판 전극 하에서 가장 높게 나타났다. 또한 에폭시 수지의 두께와 지름을 변화시켰을 때의 연면 절연 특성은 에폭시 수지의 두께가 두꺼울수록, 지름이 길수록 연면 절연 파괴 전압이 높게 나타남을 확인하였다.

• 한국공작기계학회논문집
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• 제14권1호
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• pp.8-14
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• 2005

The purposes of using cutting fluid during cutting have been cooling, lubricating, chip washing, and anti-corroding. However, the present manufacturing industry restricts the use of cutting fluid because cutting fluid contains poisonous substances which are harmful to the human body. Therefore dry cutting becomes an unavoidable assignment and a lot of researches have studied cutting methods without using cutting fluid. Because dry turning is a continuous work, tools life is reduced by continuous heat generation and surface gets rough due to reduced lubrication, so it is important to consider these situations. In this paper, the way of selecting the optimal machining condition by the minimum number of experiments and the effectiveness of using compressed air in high hardness materials through Taguchi method have been found. Dry cutting using compressed air showed better cutting characteristics than normal dry cutting with respect to by cutting force, tool wear, and surface roughness. Also, the optimal machining condition f3r dry cutting using compressed air could be selected through Taguchi method.

• 조명전기설비학회논문지
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• 제29권6호
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• pp.49-57
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• 2015

This paper presents the discharge characteristics and economic feasibility of a Dry $Air/O_2$ and a $N_2/O_2$ mixture gas in order to review $SF_6$ alternative. From AC discharge experiment in an quasi-uniform field, it was found that the optimal $N_2/O_2$ mixing ratio which breakdown voltage and surface flashover voltage were the highest was 70/30 and that the pressure dependence on the breakdown voltage was higher than that of the surface flashover voltage in the Dry $Air/O_2$ and the $N_2/O_2$ mixture gas. The mixing ratio (70/30) and the tendency of the pressure dependence were described in detail based on physical factors (impact ionization coefficient, electron attachment coefficient, secondary electron emission coefficient) involved in discharge mechanism and a electron source, respectively. In addition, the performance insulation and the economic feasibility of the Dry $Air/O_2$ and the $N_2/O_2$ mixture gas were discussed so that Dry $Air/O_2$ mixture gaswas more suitable than $N_2/O_2$ mixture gas to the $SF_6$ alternative.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1532-1533
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• 2011

고압배전반과 같은 고전압 전력기기의 절연매질로는 고체 절연매질이 사용되기도 하지만 주로 공기나 $SF_6$와 같은 기체가 사용된다. 공기를 절연매질로 사용하고 있는 고압배전반과 같은 경우에는 장시간 운전 시 먼지나 수분 등과 같은 이물질에 의한 열화현상이 보고되고 있으며, $SF_6$를 사용하는 고압배전반의 경우에는 최근 온실효과와 같은 환경오염의 원인으로 지목되고 있는 등의 문제점을 가지고 있다. 따라서 이와 같은 열화현상이나 환경오염 유발과 같은 문제점을 해결하기 위한 방안 중의 하나로서 공기 중의 수분을 제거한 dry air를 이용한 친환경 고압배전반의 개발에 관한 연구가 활발히 이루어지고 있다. 본 연구에서는 dry air의 절연내력특성에 관한 실험을 수행하여 일반 공기의 절연내력특성과 비교하였다.