• 제목/요약/키워드: Sieve

검색결과 526건 처리시간 0.027초

Precise Test Sieves Calibration Method Based on Off-axis Digital Holography

  • Abdelsalam, Dahi Ghareab;Baek, Byung-Joon;Kim, Dae-Suk
    • Journal of the Optical Society of Korea
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    • 제15권2호
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    • pp.146-151
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    • 2011
  • We describe, throughout a Mach-Zehnder interferometric configuration, a new test sieves calibration method based on off-axis digital holography. The experiment is conducted on a test sieve of square openings. The nominal sieve opening is 1.00 mm with maximum individual opening of 1.14 mm in size. The recorded off-axis hologram is numerically processed using Fresnel transforms to obtain an object wave (amplitude and phase). From the reconstructed phase, the average size of the illuminated openings has been measured precisely. The proposed method can provide a real time solution for calibrating test sieves very precisely and with moderate accuracy.

Effects of Annealing on the Structural Deformation of Polyelectrolyte Complexes based on Two Anionic Polysaccharides

  • Kim, Sang-Gyun;Lee, Kew-Ho
    • Korean Membrane Journal
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    • 제10권1호
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    • pp.39-45
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    • 2008
  • Polyelectrolyte complex based on two anionic polysaccharides, composed of sodium alginate and carrageenan, were prepared by interacting with divalent calcium ions in solution. The effects of annealing on the structural deformation of polyelectrolyte complex and on their characteristics at removing water from a methanol mixture from the point of molecular sieve were investigated and discussed. The result showed that the structural deformation of the annealed polyelectrolyte complex has an effect on the free volume between these polymer chains and the chelate segments such a shrinking of the overall morphology, which act as a molecular sieve in the separation of methanol and water mixtures.

혼합형 병렬처리 및 파이프라이닝을 활용한 소수 연산 알고리즘 (Performance Enhancement of Parallel Prime Sieving with Hybrid Programming and Pipeline Scheduling)

  • 유승요;김동승
    • 정보처리학회논문지:컴퓨터 및 통신 시스템
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    • 제4권10호
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    • pp.337-342
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    • 2015
  • 이 논문에서는 소수 추출 방법인 Sieve of Eratosthenes 알고리즘을 병렬화하여 실행 시간과 에너지 소모 면에서 개선된 효과를 얻고자 실험을 진행하였다. 성능 개선을 위해 부하 균등화를 정교하게 조절하도록 파이프라인 작업 방식을 도입하였고, 멀티코어 컴퓨터 클러스터에 하이브리드 병렬 프로그래밍 모델을 활용하여 효과를 높였다. 소규모 컴퓨터 클러스터와 저전력 컴퓨터에서 구현, 실험한 결과 이전 방식보다 연산 속도가 향상되었고, 에너지 사용량도 감소함을 확인하였다.

화학적 표면처리에 의한 천연 제올라이트의 흡착 및 분자체 특성 (Adsorption and Molecular Sieve Properties on the Natural Zeolite with Chemical Surface treatment)

  • 조승래;심미자;김상욱
    • 한국표면공학회지
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    • 제25권3호
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    • pp.144-149
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    • 1992
  • The adsorption and molecular sieve characteristics of water, methanol, ethanol, butanol and benzene on acid-alkali treated natural zeolite from Kampo area were investigated by the Diamond·Kinter method, and it was compared with synthetic zeolite A. Adsorption amount of water increased with the treatment of acid rather than the treatment of alkali. Similar tendency was observedd in adsorption of alcohols such as methanol, ethanol and butanol, but the amount of adsorption decreased. From the views of the molecular size, adsorption amount of benzene decreased because of surface activity according to the cations species rather than chemical treatment. And it was almost same value that the amount of adsorption was compared acid treated natural zeolite with synthetic zeolite A.

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시멘트입도가 강도에 미치는 영향

  • 임창덕
    • 시멘트 심포지엄
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    • 5호
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    • pp.88-93
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    • 1977
  • 시멘트 입도는 수화반응 속도에 밀접한 관계가 있으며 이로 인한 강도 발현 및 제반 물리특성에 크게 기여한다. 따라서 제품관리에 Blaine 및 sieve test로서 분말도를 check하고 있는바 이 분말도가 cement 물리특성에 미치는 영향을 실험실적으로 검토하였다.

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유동층에서 dry sorbent를 이용한 CO2 제어에 관한 연구 (Study on Carbon Dioxide Control by Using Dry Sorbent in Fludized Bed)

  • 이상섭;김민철;유정석;문길호;오광중
    • 청정기술
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    • 제9권4호
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    • pp.179-187
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    • 2003
  • 건식 흡착제를 이용한 유동층 공정에 관한 기술은 이산화탄소 처리 비용을 철강하고 효율적으로 운전될 수 있는 신기술이라고 할 수 있다. 따라서, 본 연구에서는 유동층 공정에서 건식 흡착제를 사용할 때 조업변수에 따른 이산화탄소 제어에 대해 살펴보고, 이산화탄소 흡착능과 압력강하에 대해서 고정층 공정과 비교하였으며, 활성탄, 활성 알루미나, 분자체 5A, 분자체 13X의 이산화탄소 흡착능을 각각 살펴보았다. 연구 결과, 유동층 공정의 운전을 위한 기초자료를 얻을 수 있었고, 유속이 증가할수록 유동층 공정은 상대적으로 높은 이산화탄소 흡착능과 낮은 압력강하를 지니는 것으로 나타났다. 그리고, 분자체 5A는 다른 건식 흡착제들보다 1.1~3.0배 파괴점이 늦게 나타났으며, 1.1~2.7배 높은 흡착능을 보였다.

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EFFECT OF ORCHARDGRASS GROWTH STAGE ON POOL SIZE AND KINETICS OF DIGESTA PARTICLES IN THE RUMEN OF SHEEP

  • Ichinohe, T.;Tamura, T.;Ueda, K.;Okubo, M.;Asahida, Y.
    • Asian-Australasian Journal of Animal Sciences
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    • 제8권3호
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    • pp.267-273
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    • 1995
  • The differences in rumen particle pool size, passage rate and rumen degradability in sheep receiving three varieties of orchardgrass hay harvested at pre-heading (H1), early-bloom (H2) and late-bloom (H3) were investigated using four ruminal-cannulated wethers (68 kg) fed 1,300 g of the hay once a day. Representative samples of whole rumen contents were collected at different times after feeding and the quantities of rumen particle pools [large particle pool (LPP), retained on a $1,180{\mu}m$ sieve; small particle pool (SPP), retained on a 47 but passed a $1,180{\mu}m$ sieve; and soluble fraction (SOL), passed a $47{\mu}m$ sieve (SOL)] were determined by a wet-sieving technique. The fullowing results were obtained: 1) The dry weight of whole rumen contents were significantly lower (p < 0.05) for HI than for H2 or H3. The reduction rate of whole rumen contents was slightly but significantly greater for HI that, the other hay varieties. 2) The LPP disappearance rates were 26.2, 25.3 and 21.7 g DM/h for H1, H2 and H3, respectively, and no statistical differences were found among the hay varieties. Appreciable changes were not observed with SPP and SOL throughout measurements for all hay varieties; however the SPP was markedly greater (p <0.05) for H2 and ill than for HI, while SOL did not differ among hay varieties. 3) The SPP passage rate (g DM/h) and effective rumen degradability (%) for HI, H2 and ill were, respectively, 9.7, 56.6; 16.9, 42.3; and 18.0, 28.9. The ruminal tum-over rate for SPP appeared to be higher for HI than for the other hay varieties.

강릉·태백지역 석탄광산의 탄 및 호흡성 탄분진중 금속 농도 비교에 관한 연구 (Determination of Metals of Coal and Respirable Coal Dust in Gangneung and Taebaek Coal Mines)

  • 김해정;최호춘;정호근
    • 한국산업보건학회지
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    • 제1권1호
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    • pp.82-88
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    • 1991
  • Determination of Cu, Fe, Ni, Pb, and Zn concentrations in coal and respirable coal dust were performed by atomic absorption spectrophotometry. The coal samples of 18 coal mines in Gangneung area were collected and 25 coal mines in Taebaek area. Crushed coal samples were divided into three mesh sizes. The results were as follows : 1. Metal concentrations of coals in Gangneung area by sieve sizes( -100/+200 mesh, -200/+325 mesh, -325 mesh) were as follows: Cu ; 20, 18, 19, Fe ; 1,830, 1,765, 1,107, Pb ; 6, 8, 14, Ni ; 17, 17, 14, Zn ; 4, 2, $4{\mu}g/g$, respectively. Metal concentrations in coals in Taebaek area by sieve sizes(-100/+200 mesh, -200/+325 mesh, -325 mesh) were as follows: Cu ; 30, 32, 26, Fe ; 1,741, 1,822, 1,773, Pb ; 8, 9, 7, Ni ; 13, 13, 13, Zn ; 8, 5, $4{\mu}g/g$, respectively. There were not significant differences of Cu, Fe, Ni, Pb, and Zn concentrations of coals statistically in Gangneung and Taebaek area by sieve size. 2. Metal concentrations of coals in Gangneung and Taeback area were as follows : Cu ; 19, 30, Fe ; 1,514, 1,778, Pb ; 9, 8, Ni ; 16, 13, Zn ; 3, $6{\mu}g/g$, respectively. Differences of copper and zinc concentrations of coal samples were significant between Gangneung and Taebaek area, but those of iron, nickel and lead concentrations were not significant. 3. Copper, iron, lead, nickel and zinc concentrations of coals and respirable coal dust were as follows : Cu ; 30, 6, Fe ; 1,779, 5,075, Pb ; 8, 7,814, Ni ; 13, 5,681, Zn ; 5, $134{\mu}g/g$, respectively. Differences of nickel, lead and zinc concentrations were significant between coals and respirable coal dust but those of copper and iron concentrations were not significant.

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