• 제목/요약/키워드: clean technique

검색결과 239건 처리시간 0.025초

비접촉형 마그넷기어를 적용한 클린 반송장치의 개발 (Development of Non-Contact Conveyor for Clean Process by Applying Magnet Gears)

  • 오영진;노태정
    • 한국산학기술학회논문지
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    • 제11권10호
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    • pp.3633-3640
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    • 2010
  • 헬리컬형으로 자화된 영구자석을 이용한 비접촉 마그넷 기어를 개발하기 위하여 3차원 FEM 해석 기법을 활용하였고 마그넷 기어의 자기적 특성 해석 및 설계 요소기술을 확보하였다. 마그넷 기어를 이용한 클린 반송 컨베이어 및 회전장치의 성능평가를 위하여 class 10의 클린부스 환경에서 시험운전을 거쳐, 이송 속도, 최대 허용 토크, 클린도, 최대 이송 중량, 헌팅 유무, 소음도 등을 측정한 결과 클린도 class 10의 공정까지도 대응이 가능한 것으로 확인되었다.

폐기물 매립지 토양에서의 PCBs 분석법

  • 이정화;전치완;정영욱
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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    • pp.199-201
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    • 2005
  • This paper describes a simple procedure for the quantitative analysis of 7 PCBs (polychlorinated biphenyls) in soils on the waste reclaimed land, The procedure involved sample clean up using silicagel column, acetonitrile partition and sulfuric acid procedures. The instrumental technique is applied GC/PDD(gas chromatography/pulsed discharge detector) and GC/ECD(gas chromatography/electron capture detector). Concentration of $sub-{\mu}g/g$ level was attainable with 20g soils on the waste reclaimed land.

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Fabrication of Ozone Bubble Cleaning System and its Application to Clean Silicon Wafers of a Solar Cell

  • Yoon, J.K.;Lee, Sang Heon
    • Journal of Electrical Engineering and Technology
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    • 제10권1호
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    • pp.295-298
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    • 2015
  • Ozone micro-bubble cleaning system was designed, and made to develop a unique technique to clean wafers by using ozone micro-bubbles. The ozone micro-bubble cleaning system consisted of loading, cleaning, rinsing, drying and un-loading zones, respectively. In case of the cleaning the silicon wafers of a solar cell, more than 99 % of cleaning efficiency was obtained by dipping the wafers at 10 ppm of ozone for 10 minutes. Both of long cleaning time and high ozone concentration in the wet-solution with ozone micro-bubbles reduced cleaning efficiency because of the re-sorption of debris. The cleaning technique by ozone micro-bubbles can be also applied to various wafers for an ingot and LED as an eco-friendly method.

유동가시화를 통한 자유표면과 와류 수직반응에 대한 실험적 연구 (Experiments on Columnar Vortex with Free Surface using LIF (Laser Induced Fluorescence) Technique)

  • 김석우;김경훈;이승환
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 춘계학술대회논문집B
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    • pp.734-739
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    • 2000
  • Vortices terminating at free surface have been investigated extensively. Most of investigations, however, are focused on surface parallel vortices and little has been known about surface normal vortex or columnar vortex. Visualized experimental results utilizing LIF technique are discussed for the purpose of characterization of columnar vortex interacting with a clean and a contaminated free surfaces in the present investigation. The results reveal that surface tension changes due to surface contamination although bulk viscosity remains constant and eventually the behavior of a columnar vortex interacting with a contaminated free surface is totally different from the clean free surface case.

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강인한 화자 확인을 위한 히스토그램 개선 기법 (Histogram Enhancement for Robust Speaker Verification)

  • 최재길;권철홍
    • 대한음성학회지:말소리
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    • 제63호
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    • pp.153-170
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    • 2007
  • It is well known that when there is an acoustic mismatch between the speech obtained during training and testing, the accuracy of speaker verification systems drastically deteriorates. This paper presents the use of MFCCs' histogram enhancement technique in order to improve the robustness of a speaker verification system. The technique transforms the features extracted from speech within an utterance such that their statistics conform to reference distributions. The reference distributions proposed in this paper are uniform distribution and beta distribution. The transformation modifies the contrast of MFCCs' histogram so that the performance of a speaker verification system is improved both in the clean training and testing environment and in the clean training and noisy testing environment.

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PRESERVATION OF QUALITY AFTER BROWN RICE DRYING

  • Goto, Kiyokazu;Miwa, Yoshihiro
    • 한국농업기계학회:학술대회논문집
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    • 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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    • pp.878-885
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    • 1996
  • The brown rice drying is effective for energy saving and cost reduction. However, deterioration after drying is one problem, because the skin damage occurs during the drying. So, the measures to preserve the quality has been investigated. One of major quality deteriorations is the oxidation of fat which is contained in the bran layer. So, milling should be carried out to remove the fat as soon as possible after brown rice drying. And the low temperature storage is also worth to be examined for prevention of oxidation. The effect of skin damage on the increase of fat oxidation was clarified. For the grain of skin damage, the increased of fatty acid vaule was remarkable after 70 days elapsed from occurrence of skin damage even in $15\;^{\circ}C$ condition. Therefore it is impossible to keep grain as brown rice form after brown rice drying. For the clean rice and excessively milled rice, the quality can be preserved even in high temperature of $30\;^{\circ}C$. Therefore the brown rice drying can b applied practically using the clean rice technique.

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반도체 클린룸용 수증기 응축식 에어와셔 시스템의 성능평가 (An Experiment on Performance Evaluation of a Vapor Condensation Type Air Washer System for Semiconductor Clean Rooms)

  • 여국현;박상태;유경훈;손승우
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2006년도 하계학술발표대회 논문집
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    • pp.442-447
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    • 2006
  • In semiconductor manufacturing clean rooms, it becomes important to remove airborne molecular contaminants as well as particulate contaminant in outdoor air introduced into clean rooms. One suitable control technique for these chemical contaminants is air washing by water in an outdoor air handling unit. In order to enhance the removal efficiency of chemical contaminants the effect of adding a heating and humidifying process before an air washer was examined.

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정수장에서 회전 분사 노즐을 사용한 여과사 세척에 관한 연구 (A Study on the Rotating Jet Nozzle for Washing Sand Filter in Water Purification Plant)

  • 이주호;박승헌
    • 대한안전경영과학회지
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    • 제4권3호
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    • pp.177-187
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    • 2002
  • The contamination problem is getting worse now a day because of the industrial activities. Recently it has been announced that there's environmental hormone in river and lake which produces clean water, also there's too many of algae reproduces under the water and some virus in the drinking water. The quality of water is very important. pure and clean water is not only a precondition for human being to live but a basic factor to improve the quality of life. so a water purification system must be developed. This study is about the surface washing treatment technique. We tried to use a rotary nozzle to get a tush degree of efficiency, for it was not enough with present way of washing. The nozzle is run by water pressure. The results of the experiment are as follows. We got a clean and equal surface after washing. After washing, the water's maximum consistency was 330NTU and it shows that this way is better than before one with 215NTU. Clean level of the filter was 6$^{\circ}$and it's 2.8 times higher than 17$^{\circ}$with the old way. We can see the results that the new way of washing is more effective than old way based on this study.