• 제목/요약/키워드: Wet test

검색결과 786건 처리시간 0.029초

준설토를 이용한 지하구조물 뒷채움 다짐특성에 관한 연구 (The Study on the Compaction Characteristics of Underground Structural Backfill with Reclaimed Soil)

  • 김영웅;박기순;손형호;김종국
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 1999년도 봄 학술발표회 논문집
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    • pp.357-364
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    • 1999
  • The purpose of this study is to analysis the grain distribution and compaction characteristics of structural backfill with reclaimed soil. Five(5) reclaimed soil samples which passed #200 sieve have been used in the test. The study showed that the maximum dry density and the bearing value rate turned out to be becoming smaller when the more the quantity passed #200 sieve, the smaller the soil grain. The maximum dry density value calculated from the compaction md relative density test showed wet method > compaction method > dry method. The correlation coefficient between Rc and Dr based on the grain distribution and the compaction characteristics showed that the maximum dry density value by the wet method is little higher than the compaction method and dry method.

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Permanent Shotcrete Tunnel Linings 구축을 위한 고성능 숏크리트 개발(III)(시멘트 광물계 분말형 급결제를 사용한 습식숏크리트 현장시험시공) (Development of High Performance Shotcrete for Permanent Shotcrete Tunnel Linings (III) (Field Test of Wet-mixed Shotcrete with Powder Types Cement Mineral Accelerator))

  • 박해균;이명섭;김재권;김용하
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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    • pp.609-617
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    • 2003
  • The use of Shotcrete(Sprayed concrete) for the support of underground excavations was pioneered by the Civil engineering industry. Permanent shotcrete tunnel linings such as Single-shell, NMT(Norwegian Method of Tunnelling) have been constructed in many countries for reducing construction time and lowering construction costs instead of conventional in-situ concrete linings. Among essential technologies for successful application of Permanent Shotcrete Linings, high performance shotcrete having high strength, high durability, better pumpability has to be developed in advance. This paper presents the ideas and the first field test results of wet-mixed Steel Fiber Reinforced Shotcrete(SFRS) with powder types cement mineral accelerator. From the results, wet-mix SFRS with powdered accelerator exhibited good early strength improvement and less rebound ratio compared to the ordinary accelerator.

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흡습된 수냉각 발전기 고정자 권선의 전기적 특성 (Electrical Properties of Wet Bars in Water-cooled Generator Stator Windings)

  • 김병래;김희동
    • 한국전기전자재료학회논문지
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    • 제25권10호
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    • pp.817-823
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    • 2012
  • Insulation breakdown of water-cooled generator stator windings occurs frequently due to leakage of cooling water and absorption into the insulation material. Leakage and absorption problems of water-cooled stator windings are often found during regular preventive maintenance. To evaluate cooling water leakage and absorption, diagnostic tests were performed on two water-cooled turbine generators, which have been in service for 13 and 17 years, respectively. The test results of the measured electrical properties such as dissipation factor($tan{\delta}$), capacitance and AC leakage current for water-cooled generator stator windings with wet bars are reported in this paper.

지하 습윤 환경에서 콘크리트 구조물 균열 누수에 사용되는 주입형 보수재료의 부착 성능과 거동 대응 성능 평가의 상관성 분석 연구 (Comparative Analysis of Substrate Wet Surface Adhesion and Substrate Movement Response Performance Testing Methods for Injection Type Repair Materials Used in Leakage Cracks of Concrete Structure in Underground Environment)

  • 김수연;오규환;오상근
    • 대한건축학회논문집:구조계
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    • 제34권9호
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    • pp.19-26
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    • 2018
  • The focus of this study was centered around 15 common injection type water leakage repair materials (3 different types for each; synthetic polymer, cementitious, acrylic, epoxy, urethane) used in concrete structures of Korea and analyzing their wet surface adhesion performance in accordance to the ISO TS 16774 Test Method for Repair Materials for Water-leakage Cracks in Underground Concrete Structures, Part 4: Test Method for Adhesion on Wet Concrete Surface, and the results of this study was taken to be place under a comparative analysis with the results of the preceeding study on response to substrate movement performance study. The results of this comparative study showed that other than 1 specimen of 1 type of the acrylic and 3 specimens of 1 type of the synthetic polymer type materials, all of the 93% of the specimens used in this study showed stable adhesion on wet substrate surface, and we were able to determine that materials that have proper response properties against substrate movement are highly flexible and have high adhesion properties, but their adhesion properties on wet substrate would change based on their viscosity.

멤스 프로브 카드를 위한 깊은 트렌치 안에서 S 모양의 일체형 미세피치 외팔보 프로브 형성공정 개발 (Process Development of Forming of One Body Fine Pitched S-Type Cantilever Probe in Recessed Trench for MEMS Probe Card)

  • 김봉환
    • 대한전자공학회논문지SD
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    • 제48권1호
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    • pp.1-6
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    • 2011
  • 본 논문에서는 미세피치 프로브 카드 제작을 위한 S 모양의 일체형 외팔보 프로브 형성방법에 대하여 기술하였다. 마세 피치 프로브를 위하여 Deep RIE etching을 이용하여 실리콘 트렌치 안에 일체형 프로브 빔과 탑을 형성하는 방법을 사용하였고, 피라미드 팁의 형성을 위하여 KOH 및 TMAH 습식식각을 이용하였으며, 습식식각시 방향성을 가지는 실리콘 웨이퍼에서도 휘어진 형태의 프로브 빔을 형성할 수 있는 건식 식각 및 습식식각 방법을 제시하였다. 따라서 제작된 외팔보 형태의 프로브는 디렘(DRAM), 플레시 메모리 (Flash memory) 용 프로브 카드 제작에 사용될 뿐만 아니라 RF 소자용 프로브 카드, 아이씨 테스트 소켓 (IC test socket)용 프로브 탐침에도 사용 될 것이다.

지게차용 습식 브레이크의 스퀼소음 저감에 관한 실험적 연구 (Experimental Study for the Reduction of Wet-brake Squeal Noise in a Forklift)

  • 김태종;구자함;정의봉;김영현;주원호
    • 한국소음진동공학회논문집
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    • 제20권12호
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    • pp.1147-1152
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    • 2010
  • The wet brakes used in an industrial forklift often produce noise on braking. Elimination or reduction of this squeal noise is an important task for the improvement of comforts. In this paper, a test rig was developed which was possible for testing of brake noise and an experimental measurement on squeal noise was performed. The causes of the brake noise are identified by experimenting how the factors such as automatic transmission fluid, the groove of friction-plate pad and the material of friction-plate pad affect the squeal noise. In order to identify the squeal characteristics, the signal analyses for noise are performed by using frequency spectrums. Experimental results showed that the viscosity of automatic transmission fluid and the groove pattern of friction-plate pad largely affect the reduction of the wet brake squeal noise in an industrial forklift.

PET 필름상 형성한 전자파차폐용 박막과 그 특성 (Formation of Electromagnetic Wave Shielding Thin Film on PET Film Substrate and Their Properties)

  • 임경민;이훈성;배일용;문경만;최철수;이명훈
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2011년도 춘계학술대회 및 Fine pattern PCB 표면 처리 기술 워크샵
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    • pp.205-206
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    • 2011
  • Cu thin films for electromagnetic wave shielding were prepared on PET film and Ni-coated PET film by using Dry and Wet coating method, such as evaporation method, DC sputtering method and copper sulfate($CuSO_4$). After that, Zn thin film and Ni thin film were prepared onto the Cu thin films by using evaporation dry process and Ni electro plating wet process as a finishing treatment, respectively. The result of conductivity test and corrosion resistance test revealed Cu thin films which were formed with bigger grain size and high Cu composition rate have superior properties. Zn thin film by dry evaporation process and Ni thin film by wet electro plating process on Cu thin films were largely contributed to corrosion resistance. However, Ni thin film by wet process made conductivity of all specimen worse, the other hand, Zn thin film by dry process made it better to improve condictivity of specimens just prepared by dry process.

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수평형 재생증발식 냉방기의 성능시험 (Performance Test for a Horizontal Regenerative Evaporative Cooler)

  • 송귀은;이대영
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2006년도 하계학술발표대회 논문집
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    • pp.621-626
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    • 2006
  • Regenerative evaporative cooling is known as an environment-friendly and energy efficient cooling method. A regenerative evaporative cooler (REC) consisting of dry and wet channels is able to cool down the air stream below the inlet wet-bulb temperature. In the regenerative evaporative cooler, the cooling effect is achieved by redirecting a portion of the air flown out of the dry channel into the wet channel and spraying water onto the redirected air. In this study, a horizontal regenerative cooler is considered. In the horizontal regenerative cooler, the flow direction of evaporating water has a right angle to the flow direction of supply air. This difference was investigated with visualization technique and simplified 2-module performance test was done in a thermo-environment chamber. Optimum design configuration is changed due to the wet channel which are easily fully covered with evaporating water and block the air flow inside the channel. Applying the optimized fin configuration design with the highly wetting surface treatment, a regenerative evaporative cooler was fabricated and tested to Identify the cooling performance improvement and operation characteristics. From the experimental results at the intake condition of $32^{\circ}C$ and 50% RH, the supply temperature was measured to be around $23.4^{\circ}C$. The cooling effectiveness based on the inlet dewpoint temperature was evaluated 73% which is almost close to the design expectation.

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PVC관을 이용한 배수연구 (A Study on the Underdrainage of Wet Paddy Fields by Using P.V.C. Pipes)

  • 주재홍
    • 한국농공학회지
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    • 제12권2호
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    • pp.1960-1964
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    • 1970
  • 본시험사업기간(本試驗事業期間)이 $9{\sim}2$월초(月初) 사이기 때문에 시험포장(試驗圃場)을 임대(賃貸)하여 흡수관리설공사(吸水管理設工事)가 끝나자 이어 장려품질(品質)인 맥류(麥類) 2종(種) (밀 : 농림 4호 쌀보리 : 도원)을 파종하고 발아상태(發芽狀態)와 초기생육(初期生育)만 조사(調査)하고 나머지는 내년(來年) $1{\sim}6$월(月) 사이에 조사(調査)를 완료(完了)하고 이어 벼의 시험(試驗)을 하기로 한다.

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가속열화에 따른 옥외용 epoxy 수지 애자의 전기적특성 평가 (Evaluation on the Electrical Properties of Outdoor Epoxy Resin Insulators under Accelerated Agings)

  • 조한구;김인성;안명상
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1994년도 하계학술대회 논문집 C
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    • pp.1360-1363
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    • 1994
  • Epoxy resin insulator have good electrical properties (high electric strength, high resistivity, low dielectric loss) in addition to high mechanical strength, small dimensions and design versatility. Polymer insulator, however, are subjected to aging processes, caused by the surrounding atmosphere, which may lead to degradation of their properties. This paper describes the results of a important study on the artificial pollution test, Weather-Ometer properties and rotating wheel dip test of high voltage different aging insulators which are the most important factors for outdoor uses. Also, the objects of this paper are to (a)result of insulator under dry(wet) flashover voltage, (b)artificial pollution test of salt spay, (c)Accelerated aging test of Weather-Ometer, (d) wet and dry flashover voltage under rotating wheel dip test.

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