• Title/Summary/Keyword: particle migration

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Effect of Latex Particle Size, Base Paper Grammage and Coating Color Concentration on Printing Quality of Coated Paper (Latex 입경과 원지 평량 및 칼라농도가 도공지의 인쇄품질에 미치는 영향)

  • Lee, Y.K.;Yoo, S.J.;Cho, B.U.;Kim, Y.S.;Nam, B.K.;Choi, S.M.
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.39 no.4
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    • pp.29-37
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    • 2007
  • The effects of latex particle size, basis weight of base paper and coating color concentration on the printing quality of coated paper were investigated. Coating colors were prepared with five types of latexes having different particle sizes. Coated papers were produced with high solid coating colors and with low solid coating colors in a industrial coater, respectively. In high solid coating colors, rheology modifier was used and GCC content was high. It was concluded that, in order to control binder migration and hence print mottle, latex particle sizes shall be controlled as well as formation, sizing degree and roughness of basis paper.

An experimental study of particle deposition from high temperature gas-particle flows (고온의 기체 입자 유동으로부터 입자부착 현상에 관한 실험적 연구)

  • 김상수;김용진
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.11 no.3
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    • pp.501-508
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    • 1987
  • Experimental studies of particle (TiO$\_$2/) deposition from the laminar hot gas particle flow (about 1565K) onto the cold wall surface (about 1215K-1530K) were carried out by the 'real time' laser light reflectivity method (LLRM) and the photographs of scanning electron microscope(SEM). The LLRM was used for the measurement of thermophoretic deposition rates of small particles (d$\_$p/<3.mu.m), and the photographs of SEM were used for determining what factors control the collection of particles having diameters ranging from 0.2 to 30 microns. Two phenomena are primarily responsible for transport of the particles across the laminar boundary layers and deposition: (1) particle thermophoresis (i.e. particles migration down a temperature gradient), and (2) particle inertial impaction, the former effect being especially larger factor of the particle deposition in its size over the range of 0.2 to 1 microns. And also, this study indicates that thermophoresis can be important for particles as large as 15 microns. Beyond d$\_$p/=16.mu.m, this effect diminishes and the inertial impaction is taken into account as a dominant mechanism of particle deposition. The results of present experiments found to be in close agreement with existing theories.

Numerical analysis of melt migration and solidification behavior in LBR severe accident with MPS method

  • Wang, Jinshun;Cai, Qinghang;Chen, Ronghua;Xiao, Xinkun;Li, Yonglin;Tian, Wenxi;Qiu, Suizheng;Su, G.H.
    • Nuclear Engineering and Technology
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    • v.54 no.1
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    • pp.162-176
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    • 2022
  • In Lead-based reactor (LBR) severe accident, the meltdown and migration inside the reactor core will lead to fuel fragment concentration, which may further cause re-criticality and even core disintegration. Accurately predicting the migration and solidification behavior of melt in LBR severe accidents is of prime importance for safety analysis of LBR. In this study, the Moving Particle Semi-implicit (MPS) method is validated and used to simulate the migration and solidification behavior. Two main surface tension models are validated and compared. Meanwhile, the MPS method is validated by the L-plate solidification test. Based on the improved MPS method, the migration and solidification behavior of melt in LBR severe accident was studied furthermore. In the Pb-Bi coolant, the melt flows upward due to density difference. The migration and solidification behavior are greatly affected by the surface tension and viscous resistance varying with enthalpy. The whole movement process can be divided into three stages depending on the change in velocity. The heat transfer of core melt is determined jointly by two heat transfer modes: flow heat transfer and solid conductivity. Generally, the research results indicate that the MPS method has unique advantage in studying the migration and solidification behavior in LBR severe accident.

Comparison & Analysis for Fine Sand Migration in Filter (조립 Filter내에서 세상의 이동현상에 대한 비교분석)

  • Kim, Hyun-Ki;Kwon, Moo-Nam
    • Current Research on Agriculture and Life Sciences
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    • v.16
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    • pp.15-23
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    • 1998
  • This experiment did comparison and analysis that protected soil particle migration have affect on function of the filter and therefore fall function of the filter. Results obtained are as follows: 1.High water head makes to be much movement of fine sand and out flow of particle to the outside. The filter have large opening size that reached stability an early stage, but much fine sand is washed away. If the velocity turns fast and becomes small, blocking phenomenon is remarkable nearby the filter-sand interface. 2. The movement of fine sand that effect on function of filter depend on opening size and change of water head. Under the same condition, USCE filter and USSPL filter is reached earlier than other filter that is stability of stage, because it's opening size is large. 3. Residual quantity of fine sand migration was largly come out in order of USSPL, USCE, USBR, Newton & Hurley, Bertram filter. 4. The time required to stability of flow was taken less in order of Bertram, Newton & Hurley, USBR, USSPL, USCE filter and coefficient of permeability was highly come out in order of USBR, Bertram, Newton & Hurley, USSPL, USCE filter. 5. It proved that USCE and USSPL is suitable for the filter criteria.

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Particle migration in Torsional Flow of a Viscoelastic Solution (점탄성 용액의 비틀림 흐름에서의 입자의 이동)

  • 최형진
    • The Korean Journal of Rheology
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    • v.3 no.1
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    • pp.13-21
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    • 1991
  • 본연구에서는 단단한 구형 입자가 적은 변형속도에서 2차 유체로 간주될 수 있는 점탄성 용액의 disc-plate (비틀림)흐름에 놓였을 때의 측면 이동속도에 관하여 분석하였다. 이론적 계산을 통해 비틀림 유체 흐름에서 입자는 항상 중심쪽으로 이동하고 안쪽으로의 이 동속도의 크기는 유체의 성질과 흐름의 형태의 함수라는 것을 발견하였으며 이것은 2차 유 체에서 입자는 높은 전단속도 영역에서 낮은 전단속도 영역으로 이동된다는 예측과 일치한 다는 것을 알 수 있었다. 그러나 2차 유체 모델로 부터의 이결과는 이전연구자들에 의해 관 찰된 비틀림 유체 흐름에서의 바깥방향으로의 입자의 이동은 설명하지 못하였다.

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Studies on the Prevalence of Bovine Rotavirus Infection (송아지 Rotavirus감염증 조사)

  • 안재문;박재명;곽학구;김홍기
    • Korean Journal of Veterinary Service
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    • v.16 no.1
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    • pp.70-75
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    • 1993
  • To determine the prevalence of bovine rotavirus Infection in Chungbuk area, fecal specimen were collected from calves nth diarrhea and tested using ELISA. The positive rates were 53.8%(1 to 30days old), 19.0%(31 to 60days old), and 3.2%(over 60days old). Electrophoretic migration patterns of genomic RNA from field isolates were similar to that of NCDV strain, prototype of bovine rotavirus. Bovine rotavirus field isolate showed characteristic morphology of rotavirus particle with 80nm in diameter, using EM.

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Diameter Control of Carbon Nanotubes Using Surface Modified Fe Nano-Particle Catalysts with APS (APS로 표면 처리한 Fe 나노 입자 촉매를 이용한 CNT의 직경제어)

  • Lee, Sunwoo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.26 no.6
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    • pp.478-481
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    • 2013
  • Diameter controlled carbon nanotubes (CNTs) were grown using surface modified iron nano-particle catalysts with aminpropyltriethoxysilane (APS). Iron nano-particles were synthesized by thermal decomposition of iron pentacarbonyl-oleic acid complex. Subsequently, APS modification was done using the iron nano-particles synthesized. Agglomeration of the iron nano-particles during the CNT growth process was effectively prevented by the surface modification of nano-particles with the APS. APS plays as a linker material between Fe nano-particles and $SiO_2$ substrate resulting in blocking the migration of nano-particles. APS also formed siliceous material covering the iron nano-particles that prevented the agglomeration of iron nano-particles at the early stages of the CNT growth. Therefore we could obtain the diameter controlled CNTs by blocking agglomeration of the iron nano-particles.

Enhancement of Dyeing Fastness of Artificial Suede (3) (인조스웨드의 견뢰도 향상에 관한 연구 (3))

  • Kim, Kyung Pil;Kim, Hea In
    • Textile Coloration and Finishing
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    • v.28 no.4
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    • pp.280-289
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    • 2016
  • Silica microgel was prepared by sol-gel process and then functional groups, epoxy group and ethoxy group, were introduced on the particle by coupling treatment with 3-glysidoxypropyltrimethoxysilane. The functional silica microgel(functional SiGel) formation was identified using FT-IR spectrometry. Phase stability for DMF solution of functional SiGel, PU resin and pigment was evaluated by Turbiscan Lab. And physical properties of artificial suede including hand values, morphology and dyeing fastness were investigated. The mean particle size and the specific surface area of the functional SiGel were $0.77{\mu}m$ and $380m^2/g$. Mixture containing the functional SiGel, PU resin and pigment was more stable than the functional SiGel-free mixed solution. Artificial suede prepared by the functional SiGel had appearance and feeling close to natural suede. The migration fastness, the solvent wicking fastness and rubbing fastness of the artificial suede were enhanced to 4~5 grades, 4~5 grades and 3~4 grades, respectively.

Prediction of Remaining Useful Life of Lithium-ion Battery based on Multi-kernel Support Vector Machine with Particle Swarm Optimization

  • Gao, Dong;Huang, Miaohua
    • Journal of Power Electronics
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    • v.17 no.5
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    • pp.1288-1297
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    • 2017
  • The estimation of the remaining useful life (RUL) of lithium-ion (Li-ion) batteries is important for intelligent battery management system (BMS). Data mining technology is becoming increasingly mature, and the RUL estimation of Li-ion batteries based on data-driven prognostics is more accurate with the arrival of the era of big data. However, the support vector machine (SVM), which is applied to predict the RUL of Li-ion batteries, uses the traditional single-radial basis kernel function. This type of classifier has weak generalization ability, and it easily shows the problem of data migration, which results in inaccurate prediction of the RUL of Li-ion batteries. In this study, a novel multi-kernel SVM (MSVM) based on polynomial kernel and radial basis kernel function is proposed. Moreover, the particle swarm optimization algorithm is used to search the kernel parameters, penalty factor, and weight coefficient of the MSVM model. Finally, this paper utilizes the NASA battery dataset to form the observed data sequence for regression prediction. Results show that the improved algorithm not only has better prediction accuracy and stronger generalization ability but also decreases training time and computational complexity.

Experimental study on the sediment sorting processes of the bed surface by geomorphic changes in the vegetated channels (실내실험에 의한 혼합사 식생하도의 지형변화와 하상토 분급 특성 연구)

  • Jang, Chang-Lae
    • Journal of Korea Water Resources Association
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    • v.49 no.1
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    • pp.73-81
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    • 2016
  • This study investigates the development of lower channels and sediment sorting processes in the vegetated channels with the mixed sediment. The sediment discharges fluctuate with time and decrease with vegetation density. The bed changes with irregular patterns, and the sediment particles in the vegetated zone at the surface of bed are fine. The dimensionless geometric mean decreases with vegetation density. The fine sediment particles are trapped by vegetation, and the bed between main steam and vegetated zone increases. Moreover, the particle sizes are distributed irregularly near the zone. The hiding functions decrease with dimensionless particle size. However, the functions increase with vegetation density, which is confirmed by decreasing sediment discharge with vegetation. The lower channel is stable and the migration decreases in the condition of $0.5tems/cm^2$. However, the migration of the lower channel in the condition of $0.7stems/cm^2$ increases due to the increased sinuosity and new generated channels in the sedimentated vegetation zone.