• Title/Summary/Keyword: mesh 크기

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Fabrication of Photocatalytic $TiO_2$ Thin Film Using Aerosol Deposition Method (Aerosol Deposition 법을 이용한 광촉매 $TiO_2$ 박막 제조)

  • Choi Byung-Kyu;Min Seok-Hong;Kim Jong-Oh;Kang Kyong-Tae;Choi Won-Youl
    • Journal of the Microelectronics and Packaging Society
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    • v.11 no.4 s.33
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    • pp.55-59
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    • 2004
  • We fabricates the $TiO_2$ thin film from anatase phase $TiO_2$ powder having good photocatalytic property using aerosol deposition method at room temperature. Aerosol deposition method, which sprays an aerosol powder with ultrasonic velocity and deposits a thin film on substrate at low temperature, has the advantages of low thermal stress and low cost. To fabricate the $TiO_2$ thin film, the aerosol bath pressure and chamber pressure were 500 torr and 0.4 torr, respectively. The difference of aerosol bath pressure and chamber pressure accelerated the $TiO_2$ nano powder to ultrasonic velocity through the nozzle of $0.4 mm{\times}10 mm$ and $TiO_2$ thin film was finally formed. SS mesh with diameter of 50 mm was used as a substrate to apply the $TiO_2$ thin film to water quality purification. The raw powder was dehydrated for the good dispersion of $TiO_2$ powder. To suppress the formation of second particle, the powder was dispersed for 90 min in alcohol bath by ultrasonic treatment and desiccated. The grain size of $1 {\mu}m$ was observed in $TiO_2$ thin film deposited on SUS mesh by scanning electron microscopy (SEM). The anatase phase of $TiO_2$ thin film was also observed by X-ray diffraction (XRD) and the anatase phase of raw powder was nicely maintained after aerosol deposition. The results are applicable to water treatment filter having photocatalytic reaction.

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Nutritional Components and Physicochemical Properties of Hulled and Naked Oat Flours according to Particle Sizes (겉귀리 및 쌀귀리 분말의 입자크기별 영양성분 및 이화학적 특성)

  • Lee, Yu-Jin;Kim, Jin-Sook;Kim, Kyung-Mi;Choi, Song-Yi;Kim, Gi-Chang
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.9
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    • pp.1293-1301
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    • 2016
  • Hulled oat (Chohan) and naked oat (Choyang) flours were analyzed according to particle size to investigate nutritional components and physicochemical properties. Particle size of naked oat flours was larger than that of hulled oat flours. As the mesh of the crushed ones decreased, particle sizes increased in value. The content of total ${\beta}$-glucan was highest in hulled oat flour (4.23%) with 60 mesh and in naked oat flour (4.26%) with 100 mesh. Most total ${\beta}$-glucan was soluble ${\beta}$-glucan in both flours (over 76%). Total starch of hulled oat flours (63.64~69.82%) was higher than that of naked oat flours (52.45~63.71%). Whereas amylose contents showed a negative correlation with total starch contents. Contents of free amino acids increased according to particle size, and each component was dependent on each type of amino acid. Moreover, while fatty acid composition was not significant, the content of most naked oats was higher than that of hulled oats. Besides, the ratio of unsaturated fatty acids (oleic acid and linoleate) in both types of oat flours was relatively higher than that of other grains. The pasting properties of peak viscosity, trough, and breakdown showed the highest value in both oats with 100 mesh. Further, the values of final viscosity and the setback were higher with relatively larger particle size. In addition, peak time exhibited a lower value with larger particle size, whereas it showed the opposite value for pasting temperature. Starch digestibility did not show any specific trend according to particle size, whereas expected glycemic index of hulled oats was lower than that of naked oats. Moreover, lower values were investigated at larger particle sizes. The results of this study provide basic useful information for processing of oat products to improve consumption of oats grown in Korea.

Size selectivity of round traps for greenling (Hexagrammos otakii) in the western sea of Korea (원통형 통발에 대한 서해안 쥐노래미 (Hexagrammos otakii)의 망목선택성)

  • 신종근;박해훈
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.39 no.3
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    • pp.174-180
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    • 2003
  • This study investigated the size selectivity of the round traps for greenling (Hexagrammos otakii) in the western sea of Korea. The selection curve for the greenling from the experiments on Oct. 2000 and Ar. 2001 was fitted by Kitahara's method to a polynomial equation and two parameter logistic selection curve. The selectio curve of the latter was more reasonable than that of the former. The equation of selectivity curve obtained using a logistic function with least square method was , s(R)=1/1+exp(-1.1169R+6.4565), where R=1/m, and 1 and m are total length and mesh size, respectively. The size selectivity curve showed that the current regulated mesh size(35mm) in case of the round trap was close to the L50 (37.0mm) of the selection curve for the biological minimum length (21.4cm) of the greenling.

The Study of Milling Properties for Optimization of Treatment and Recycling of Converter Slag (제강슬래그 처리 및 재활용의 최적화를 위한 분쇄 특성에 관한 연구)

  • Kuh, Sung-Eun;Hwang, Kyoung-Jin;Kim, Dong-Su
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.6
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    • pp.1139-1148
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    • 2000
  • To treat and recycle a large quantity of converter slag. the milling properties of -14/ +24 mesh-sized slag has been considered. The optimal conditions in milling process were investigated for producing powder-type slag and the required consumption was derived for the economical grinding. The characteristics of milling processes were studied in the variation of the rotational speed, milling time, filling ratio of ball, and size and amount of feed. The grinding efficiency was also examined. The optimal rotational speed in this experimental condition was observed to be the value of 79% of critical speed. The extent of grinding was increased with increasing the grinding time. but the efficiency of milling was decreased with the time. 50% ball filling was shown to have the optimal grinding effect, and less amount and small-sized feed made the milling efficiency high. As the result, using Bond's equation, power required for efficient milling was considered and the highest value was observed in the condition of high grinding time and optimal rotational speed.

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Effect of grif size on the compututation of free-surface waves (자유표면파 계산에서의 격자크기영향)

  • 곽승현
    • Journal of Ocean Engineering and Technology
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    • v.11 no.2
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    • pp.70-76
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    • 1997
  • 수치격자의 크기제한에 의한 자유표면 유동해석 문제를 효율적으로 다루기 위하여 자유표면의 모든 격자를 x 방향으로 4,8,12개로 등분할 하고, y 방향으로는 4개로 잘라서 계산하였다. 이중격자 또는 삼중격자로 Navier-Stokes 방정식의 각항에 크기가 다른 격자를 사용해 효율을 향상시키는 계산방법의 연장으로, 본 논문에서는 자유표면 방정식에 보다 세분화된 격자를 적용해, Marker Particle 이동 및 자유수면 형성에 효율향상을 줄수 있는 수치방법을 도입하였다. 계산결과에 의하면 초기사용 격자가 coarse한 경우가 본방법의 효과가 커짐을 알 수 있고 대상물로는 층류유동에서 Wigley모형과 낭류유동의 S103 모형이다.

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Properties of Nonwaxy Rice Flours with Different Soaking Time and Particle Sizes (수침시간과 입자크기가 다른 멥쌀가루의 특성)

  • Lee, Mi-Kyung;Kim, Jeong-Ok;Shin, Mal-Shick
    • Korean Journal of Food Science and Technology
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    • v.36 no.2
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    • pp.268-275
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    • 2004
  • Effects of soaking time and particle size on physicochemical properties of nonwaxy rice flour were investigated. Nonwaxy rice grains were soaked at $4^{\circ}C$ for 0, 1, 12, and 24 hr, dried at room temperature, and milled, Resulting flours were passed through 45-mesh ($<355{\mu}m,\;IL45$) and 100-mesh ($<150{\mu}m\;IL100$) sieves and separated into $<40{\mu}m\;and\;40-100{\mu}m$ series. IL45 series showed higher amount of large particles ($40-100{\mu}m$) than IL100 series. As the soaking time increased, protein and ash contents decreased, and amylose content, water-binding capacity, swelling power, and solubity of nonwaxy rice flours increased. Swelling power and solibility of nonwaxy rice flours also increased between $65-85^{\circ}C$. Water-binding capacity, swelling power, and solubility of IL100 series were higher than those of IL45 series. 12 hr-soaked nonwaxy rice flour pastes showed higher peak viscosity and breakdown but lower setback and visicosity at $95\;and\;50^{\circ}C$ than 1 hr-soaked ones. X-Ray diffractograms of nonwaxy rice flours were not affected, whereas surface appearance was affected, by soaking time and particle size.

Link-Disjoint Embedding of Complete Binary Trees into 3D-Meshes using Dimension-Ordered Routing (순위차원라우팅을 사용한 완전 이진트리의 3차원 메쉬로의 링크 충돌 없는 임베딩)

  • Park, Sang-Myeong;Lee, Sang-Kyu;Moon, Bong-Hee
    • Journal of KIISE:Computer Systems and Theory
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    • v.27 no.2
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    • pp.169-176
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    • 2000
  • This paper is considered with the problem of embedding complete binary trees into 3-dimensional meshes using dimension-ordered routing with primary concern of minimizing link congestion. The authors showed that a complete binary tree with $2^P-1$ nodes can be embedded into a 3-dimensional mesh with optimum size, $2^P$ nodes, if the link congestion is two[14], (More precisely, the link congestion of each dimension is two, two, and one if the dimension-ordered routing is used, and two, one, and one if the dimension-ordered routing is not imposed.) In this paper, we present a scheme to find an embedding of a complete binary tree into a 3-dimensional mesh of size no larger than 1.27 times the optimum with link congestion one while using dimension-ordered routing.

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The Reduction of Crystal Formation Time of Vancomycin Using Silica Gel (실리카겔을 이용한 반코마이신 결정화 시간 단축)

  • Kim, Sung-Jae;Kim, Jin-Hyun
    • Microbiology and Biotechnology Letters
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    • v.42 no.3
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    • pp.232-237
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    • 2014
  • We investigated the effects of silica gels on the reduction of the crystallization time for the purification of vancomycin. The shortest crystallization time for vancomycin was obtained when silica gel with a pore diameter of $40-60{\AA}$ and with a particle diameter of 230-400 mesh was used as the material. The use of silica gel as a surface area increasing material dramatically reduced the crystallization time four fold (6 h) when compared with the results where the surface area had not been similarly increased. In addition, the crystal size of vancomycin was decreased with the addition of silica gel. This improved crystallization process has a significant effect on the convenience and feasibility of the purification step for vancomycin.

An Improved Mesh-free Crack Analysis Technique Using a Singular Basis Function (특이기저함수를 이용하여 개선한 Mesh-free 균열해석기법)

  • 이상호;윤영철
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.14 no.3
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    • pp.381-390
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    • 2001
  • In this paper, a new improved crack analysis technique by Element-Free Galerkin(EFG) method is proposed, in which the singularity and the discontinuity of the crack successfully described by adding enrichment terms containing a singular basis function to the standard EFG approximation and a discontinuity function implemented in constructing the shape function across the crack surface. The standard EFG method requires considerable addition of nodes or modification of the model. In addition, the proposed method significantly decreases the size of system of equation compared to the previous enriched EFG method by using localized enrichment region near the crack tip. Numerical example show the improvement and th effectiveness of the previous method.

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