• 제목/요약/키워드: Contamination

검색결과 5,488건 처리시간 0.037초

장애물의 영향에 의한 3차원 실내공간의 난류유동 및 오염물질 거동의 수치해석 (A Numerical Analysis of Turbulent Flow Field and Contamination Behavior in a Three Dimensional Room with Obstacle)

  • 정효민
    • Journal of Advanced Marine Engineering and Technology
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    • 제20권5호
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    • pp.45-57
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    • 1996
  • Flow characteristics and contamination behavior in a three-dimensional room with the desk-type obstacle have been investigated numerically by the k-${\varepsilon}$ two equation turbulence model. The room model has one supply opening on the ceiling and two exhaust openings on the side walls. Thirty six sets of calculation have been performed for twelve contamination sources of $1{\times}10^{-4}kg_c/(m^3{\cdot}s)$ strength at different inlet velocities(0.1, 1, 10m/s). This study can conclude that the source points of contaminant are located near the obstacle edge of Z-axis, at which the maximum contaminant diffusion fields are occured.

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한강수계(漢江水系)의 Alkyl Benzene Sulfonate 오염(汚染)에 관(關)한 연구(硏究) (A Study on Alkyl Benzene Sulfonate Contamination in the Han River)

  • 정기화
    • Journal of Pharmaceutical Investigation
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    • 제8권3호
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    • pp.11-15
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    • 1978
  • The contamination concentrations of the alkyl benzene sulfonate (ABS) pollution in the Han river were investigated at 3 sites from July through september, 1977. The samples were taken on the upper, the middle, and the lower Han river and 5points of each part, respectively. The contamination concentrations of ABS pollution in the river were 0.012 p.p.m of the upper site, 0.206 p.p.m of the middle site, and 0.486 p.p.m of the lower site in average, respectively. Consequently, the contamination concentrations of ABS pollution in the Han river were the highest at the lower site, where is between second Han river bridge and Nan Ji island.

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이동식 디스크 드라이브의 입자 오염에 대한 클리닝 패드의 효과 (Effect of Cleaning Pad on Particle Contamination in Removable Media Disk Drive)

  • 유신성;이정규;김대은
    • 한국정밀공학회지
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    • 제20권4호
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    • pp.183-188
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    • 2003
  • Particulate contamination is known to be a significant cause of failures of removable storage media. In this work, the effect of particles on the surface damage of removable hard disk media was investigated. The particles of different materials and size were introduced to the Head Disk Interface (HDI) using a particle injection system. It was round that the particles of particulate size and property serious damaged the media. This study showed that cleaning pad is effective for reducing particle contamination, except fer the particles of specific size and property. As a means to remove the particles of specific sire. the concept of using a stepped taper at the leading edge of the slider is proposed.

이동식 디스크 드라이브의 입자 오염 저감 방안 (A study on the decrease of particle contamination in removable media disk drive)

  • 유신성;이정규;김대은
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2002년도 추계학술대회 논문집
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    • pp.946-949
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    • 2002
  • Particulate contamination is known to be a significant cause of failures of removable storage media. In this work, The effect of particles on the surface damage of removable hard disk media was investigated. The particles of different materials and size were introduced to the head-disk interface using a particle injection system. It was found that the particles of particulate size and property serious damaged the media. This study showed that cleaning pad is effective for reducing particle contamination, except for the particles of specific size and property. As a means to removed the particles of specific size, the concept of using a stepped taper at the leading edge of the slider is proposed.

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Analysis of Microbiological Contamination in the Chosun Dynasty Textiles Exhumed from Hwasung Kupori Burial

  • Cheunsoon Ahn;Kim, Jung-wan
    • The International Journal of Costume Culture
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    • 제2권1호
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    • pp.54-61
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    • 1999
  • The purpose of this research was first to analyse and compare the types of microbes inherent among the unwashed and washed Kupori textiles, and second to investigate whether there is a difference between unwashed and washed Kupori textiles on the susceptibility of contamination by microorganism when exposed to the same microbial environment. Microbial identification procedure and the Shake Flask Test for investigating the effect of exposure to microbial environment were carried out separately. The result of microbial identification procedure indicated that a variety of bacteria and fungi were inherent in both unwashed and washed textiles and that the population of contaminated microorganism became more diverse after washing. The result of Shake Flask Test indicated that given the same exposure condition, the unwashed textiles tend to be more susceptible to bacterial contamination than the washed textiles. The results of the present study supported the current conservation procedures adopted in Korean museums which include washing and humigation procedures before long-term storage or display of exhumed textiles.

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Effect of Ar ion Sputtering on the Surface Electronic Structure of Indium Tin Oxide

  • Lee, Hyunbok;Cho, Sang Wan
    • Applied Science and Convergence Technology
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    • 제25권6호
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    • pp.128-132
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    • 2016
  • We investigated the effect of Ar ion sputtering on the surface electronic structure of indium tin oxide (ITO) using X-ray and ultraviolet photoelectron spectroscopy (XPS and UPS) measurements with increasing Ar ion sputtering time. XPS measurements revealed that surface contamination on ITO was rapidly removed by Ar ion sputtering for 10 s. UPS measurements showed that the work function of ITO increased by 0.2 eV after Ar ion sputtering for 10 s. This increase in work function was attributed to the removal of surface contamination, which formed a positive interface dipole relative to the ITO substrate. However, further Ar ion sputtering did not change the work function of ITO although the surface stoichiometry of ITO did change. Therefore, removing the surface contamination is critical for increasing the work function of ITO, and Ar ion sputtering for a short time (about 10 s) can efficiently remove surface contamination.

소규모 돼지도축공정에서 도체오염 미생물의 변화 (Microbial change of pork carcass during processing in small size slaughterhouse)

  • 홍종해;이경환;이성모
    • 한국동물위생학회지
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    • 제25권1호
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    • pp.31-37
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    • 2002
  • Major hazards existed in slaughterhouse are pathogenic microorganisms originated from intestinal microflora of slaughtered animals. This study was intended for the identification of microbial contamination sources during pork slaughtering in small plants. Total aerobic bacteria, Coliform group, Salmonella spp, Listeria monocytogenes, and Campylobacter jejuni/coli were isolated from the surface sample of pork carcasses. Contamination level among different sampling points of ham, belly and neck did not showed statistical differences. Therefore, the mixed sampling from belly and neck of carcass could be effective for microbiological monitoring. Isolation rates of pathogenic microorganisms showed Salmonella spp 20.9%, Listeria monocytogenes 10.5%, and Campylobacter jejuni/coli 8.1% from 296 sampling points. High prevalence rate of Salmonella spp indicated that the contamination of intestinal microflora occurred due to unsanitary processing control, which required HACCP system in small plants. It was recommended that the prerequisite program should be a key factor for a successful HACCP system implementation especially in small size slaughterhouse.

Effect of Contamination of Liquid Crystal by Spilled Components from Color Filter

  • Kim, Young-Seok;Lee, Jeong-No
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.1469-1471
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    • 2009
  • Effect of contamination of liquid crystal on the electrical behavior of liquid crystal display (LCD) by spilled components from color filter layer was investigated. It is noted that the level of contamination was different following the kind of liquid crystal and organic layers. Transmittance curve of LCD cell was shifted by spilled components of color filter and BM materials. C-V curve also showed different behavior following color filter type. The results obtained show the image sticking of LCD can be varied by pairing liquid crystal with color filter materials.

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Study of point defects caused by a thin contamination layer in a-Si TFT-LCD

  • Oh, Jae-Young;Lee, Jae-Kyun;Yang, Moung-Su;Kang, In-Byeong
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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    • pp.845-848
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    • 2007
  • Analysis of point defects invisible by a microscope has been studied on the a-Si thin film transistor panel. The point defects which were named Invisible Point Defect (IPD) is characterized by no particles or distortion of patterns on a pixel structure and randomly distributed on panels. To investigate the IPD, measurements were carried out: gray level driving, transistor transfer characteristic, focused ion beam (FIB), and secondary ion mass spectrometry (SIMS). The results showed that a contamination layer had a bad influence on an active surface. The contamination layer consisted of oxygen and iron from a water supply line during cleaning process. After the process tuning, IPD has been stabilized.

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지리적 영향에 따른 염해 오손물질의 분포에 관한 연구 (The Distribution of Salt Contamination with the Influence of Geographical Condition)

  • 장태인;양병모;강연욱;한상옥
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 C
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    • pp.1782-1784
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    • 2000
  • This paper present the result of the investigation, the distribution of salt contamination with the influence of. geographical condition. To get the ESDD data, a conventional brush washing method was adapted, and IC(ion chromatography) was used to measure the quantity of anions, such as $Cl^-$ and ${SO_{4}}^{2-}$. And we make an analysis on the distribution of salt contamination with the increase of distance from shore. With 10 month ESDD data, we seek the 95% ESDD value with interpolation method. With these analyses, we had obtained the formulation concerned with the distance from sea. And could know the composition of contamination.

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