• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전력기술부문
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• pp.454-456
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• 2003

This paper describes a type test results of 154 kV transmission line arrester with external gap. The test was carried on surge arrester unit and line arrester with external gap, respectively. Withstand voltage test demonstrate the voltage withstand capability of the line arrester with external series gap under the dry and wet conditions. In insulation coordination test external series gap shall be discharged every time when lightning impulse voltage with the steepness of more than 1500 $kV/{\mu}s$ are applied under the wet condition.

• 생태와환경
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• 제40권2호
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• pp.173-183
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• 2007

본 연구에서는 국내외 독성시험법 중에서 시험종이 국내에 서식하는 경우를 대상으로 사용된 노출 기간, 종말점 등 시험 세부 조건을 집약하여, 향후 생태독성 시험법개발 연구를 위한 각각의 생물종별 생태독성 시험법의 적용 가능한 시험 세부 조건별 범위와 생태독성평가기법 구축을 위한 방향을 제시하였다. 기존에 국내 생물종을 대상으로 국내외에서 수행된 바 있는 독성 시험법에 대한 연구 사례를 검토한 결과, OECD등의 표준시험법에서 추천한 시험종을 대상으로 한 독성자료가 상당 부분을 차지하였다. 또한 표준시험법의 공시어종 이외에도 국내 생물종에 대한 소량의 연구 자료가 있었으나, 대체로 표준시험법을 개별 상황에 맞게 수정하여 적용한 것으로 나타났다. 특히 온도는 Carassius auratus < Gasterosteus aculeatus < Oryzias latipes < Misgurnus anguillicaudatus 순으로 낮아지는 것으로 보아, 어류독성시험에 있어서 가장 유의해야 할 조건인 것으로 나타났다. 이와 같이 국내 생물종을 이용한 생태독성평가 기반이 미약한 현시점에서 보다 체계적인 독성시험법을 개발하기 위해서는 향후 실험 조건과 동일한 시스템 하에서의 생활사 측정 및 그에 따른 노출기간 설정, 본 연구에서 선정한 어류 5종을 대상으로 도출한 생태독성시험기법에 대한 실험 연구를 통한 검증 그리고 기존 연구에서 다루지 않았던 많은 국내 시험종 개발 및 그에 따른 실험 조건 규명이 선행되어야 할 것이다. 따라서 본 연구는 국내 생물종을 대상으로 한 독성시험기법 및 방향을 제시함으로써 국내 수계의 실정, 먹이 연쇄를 통한 생물종간의 상호 관련성 등을 고려할 수 있는 국내 시험종 및 그에 따른 시험법 개발을 위한 중요한 토대가 될 것으로 사료된다.

• 설비공학논문집
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• 제9권2호
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• pp.153-162
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• 1997

In this study, the wet surface heat transfer coefficients and friction factors of the heat exchanger with slit-wavy fin were measured. Four sample cores of two or three row with fins of 12 fpi or 16 fpi were tested. Tests were conducted in a closed loop wind tunnel, where the heat exchanger was mounted at 45 degree inclination angle. The wet surface heat transfer coefficient was reduced following the procedure given in ARI 420-81. During the course, new definitions of the $\varepsilon$-NTU applicable to enthalpy driving system were introduced. The wet surface heat transfer coefficients were approximately equal to the dry surface values. However, the friction factors were approximately 120% to 170% higher than those of the dry surface. Both the heat transfer coefficient and the friction factor of the wet surface increased as the relative humidity increased, fin pitch decreased, and the number of row decreased, although the difference was not large.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.88-89
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• 2009

In this paper, we investigated about wet cleaning effect as deep trench formation methods for Power chip devices. Deep trench structure was classified by two methods, PSU (Poly Stick Up) and Non-PSU structure. In this paper, we could remove residue defect during wet. cleaning after deep trench etch process for non-PSU structure device as to change wet cleaning process condition. V-SEM result showed void image at the trench bottom site due to residue defect and residue component was oxide by EDS analysis. In order to find the reason of happening residue defect, we experimented about various process conditions. So, defect source was that oxide film was re-deposited at trench bottom by changed to hydrophobic property at substrate during hard mask removal process. Therefore, in order to removal residue defect, we added in-situ SCI during hard mask removal process, and defect was removed perfectly. And WLR (Wafer Level Reliability) test result was no difference between normal and optimized process condition.

• 펄프종이기술
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• 제42권3호
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• pp.7-13
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• 2010

KOptimization and control of wet-end process provide a key solution to improve paper quality and production efficiency at the same time. Wet-end of paper machine is to determine three important influencing factors of papermaking i.e., retention, drainage and formation. Good formation of paper could be made at the cost of deteriorated retention or drainage. In the same manner increase of retention aid could cause the bad formation of paper. It is very important to find a proper retention chemical which may satisfy one of three factors without the sacrifice of other two. Laboratory scale analyzing or screening chemical additives of wet-end was reported in this study based on RDA sheet molding. Different from the conventional test method, simultaneous consideration of three important wet-end properties could be made by RDA and consequently more reliable prediction of actual paper machine wet-end could be expected.

• Geomechanics and Engineering
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• 제28권4호
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• pp.375-384
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• 2022

The glacial tills and shales in Midwestern states of the USA often show strength degradation after construction. They are often in need of applying soil modification techniques to remediate their strength degradation with weathering process. This study investigated the weathering durability of these natural soils and biopolymer treated soils by comparing direct shear test results for wet-dry and wet-freeze-thaw-dry cycled specimens. The tests showed that untreated glacial tills maintained only 62% and 50% initial shear strength after eight wet-dry cycles and eight wet-freeze-thaw-dry cycles, respectively. These untreated soils could not withstand by themselves after 16 weathering cycles. The same soils treated with 1.5% (by dry weight) food-grade Xanthan gum maintained 140% and 88% initial shear strength of untreated soils after 16 weathering cycles for wet-dry cycles and wet-freeze-thaw-dry cycles, respectively. The same soils treated with 1.5% (by dry weight) Gellan gum maintained 82% and 60% initial shear strength of untreated ones after 16 weathering cycles, respectively. Similar results were obtained for crushed shales, manifesting that the biopolymerization method may be adopted as a new eco-friendly method to enhance the weathering durability of these problematic soils of glacial tills and shales.

• 한국방사선학회논문지
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• 제12권3호
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• pp.305-312
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• 2018

유리 표면에 방사성동위원소 $^{14}C$를 고착시키고 문지름 시험을 통해 시험용지별 전이 인자와 표면 형상을 관찰하여 방사성동위원소 누설 점검을 위한 건식 및 습식 문지름 시험법을 연구하였다. 건식 문지름 시험법은 티슈 용지가 종이 필터를 대체 가능할 정도로 2배 높은 전이 인자를 보였고, 습식 문지름 시험법은 종이 필터 용지가 티슈 용지에 비하여 3배 높은 전이 인자를 보였다. 일반적으로 누설 점검을 위해 종이 필터를 사용하고 있지만 건식 문지름 시험법에서 티슈 용지가 대안이 될 수 있음을 보였다.

• 드라이브 ㆍ 컨트롤
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• 제15권3호
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• pp.14-20
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• 2018

Wet clutches in an automatic transmission enable the transmission of the engine power by the frictional torque experienced and noted between disk and plates. Since the clutch frictional torque considerably affects the shift quality of an automatic transmission as well as the durability of the machinery, its friction characteristics must be carefully examined to meet the design requirements. The SAE No. 2 friction test machine is a well-known standard to evaluate mainly the friction characteristics of plate clutches along with the required automatic transmission fluids. This paper reviews the experimental analysis of the wet clutch friction characteristics by using the exclusively developed clutch test machine which is capable of controlling the clutch test procedure, in accordance with the applicable test standard and processing of the experimental data automatically. As the clutch test machine is designed for the accommodation of dual clutches which is applied to the real transmission, it can evaluate not only the clutch friction characteristics, but also an actuation performance of a measured clutch piston. In respect to friction characteristics involving dynamic friction coefficients, the energy absorbed in a clutch disk and the recorded temperatures of clutch plates during braking actions and procedures are also investigated. Additionally, the change of friction coefficients by the use of the repeated clutch application is also observed with the endurance test functions of an accurately calibrated and dedicated clutch test machine.

• 한국안광학회지
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• 제20권4호
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• pp.455-462
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• 2015

목적: 친수성 콘택트렌즈 정점굴절력 측정 방식중 하나인 wet cell 측정법을 활용한 국산화 측정 홀더와 프로그램 개발에 관한 연구를 위해 현재 사용되어지고 있는 Poster wet cell 홀더와 함수율별 굴절력의 측정값을 비교 분석하였다. 방법: 안경원에서 사용 중인 기존 제품과 새롭게 개발된 국산제품에 식염수를 채워 넣고 소프트콘택트렌즈의 굴절력을 측정하였다. 실험에 사용한 친수성 콘택트렌즈는 안경원에서 많이 사용되고 있는 국내산 렌즈를 사용하였으며, 함수율별과, 구면굴절력별로 분류하여 각각 실험하였다. 결과: wet cell 방식으로 콘택트렌즈 굴절력 측정 시 새롭게 개발한 홀더의 경우 자동렌즈미터를 사용하여 굴절력을 측정한 결과 -3.00 D에서 함수율 38%는 -3.01 D, 함수율 45%는 -3.00 D, 함수율 58%는 -2.98 D로 측정되었으며, Poster wet cell 홀더를 사용하여 렌즈를 측정한 결과 -3.00 D에서 함수율 38%는 -3.60 D, 45%는 -3.06 D, 58%는 -2.46 D로 각각 측정되었다. 결론 : 고함수율에서 굴절력 측정값은 wet cell 방식의 두 홀더 모두 낮게 나타났으며, 새롭게 개발된 홀더와 프로그램을 통한 자동렌즈미터의 측정값이 기존의 Poster soft contact lens wet cell 측정방식에 비해 더 정확한 굴절력 측정 결과를 나타내었다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2008년도 추계 학술논문 발표대회
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• pp.49-52
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• 2008

The present study was to develop a dry PFB method similar to the existing gypsum board construction method in order to apply the existing wet PFB method that uses fire-resistant adhesive. It was found that the existing wet method can produce concrete compressive strength of 80MPa and fire resistance of 3 hours with 30mm PF boards. The goal of development in this study was fire resistance of 3 hours through dry construction of 15mm fire-resistant boards. 1. Improved PF board was prepared by adding inorganic fiber to existing board and using aggregate with grain size of 3mm or less. Molding was done at temperature higher than that for existing PF board molding. While wet curing is used for existing PF boards, this study used dry curing in order to enhance heat insulation performance. 2. According to the results of fire resistance test, when the dry PF method was applied, the temperature of the main reinforcing bar was 116℃ in 15mm, 103.8℃ in 20mm, and 94℃ in 25mm, and these results satisfied the current standards for fire resistance control presented by the Ministry of Land, Transport and Maritime Affairs. When a 3-hour fire resistance test was performed and the external properties of the specimen were examined, the outermost gypsum board hardly remained and internal PF board maintained its form without thermal strain.