• Title, Summary, Keyword: Packing density

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The Effect of Packing Density on the Warpage Behavior of Ni-Zn-Cu Ferrite Sheets (Ni-Zn-Cu계 페라이트 시트에서 충진 밀도에 따른 시트 휨 현상)

  • Kim, Shi Yeon;Yeo, Dong-Hun;Shin, Hyo-Soon;Song, Woo Chang;Yoon, Ho Gyu
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.12
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    • pp.781-786
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    • 2015
  • It is necessary for ferrite sheets to be fabricated with high packing density for excellent electrical properties and high strength. In this study, the relationship between the warpage and the packing density of ferrite green sheet, was investigated with amount variation of organic additives. With 0.4 wt% of dispersant, the packing density was about 48% and warpage appeared 0.5~1.3 mm high. With 1.4 wt% of dispersant, the packing density increased up to 57% and warpage appeared 0.8~2.1 mm high. With high packing density, warpage appeared along the edges of specimen, while with low packing density, deformation appeared over whole specimen inhomogeneously. It is thought that inhomogeneous deformation after sintering came from the inhomogeneity in green sheet prepared with badly dispersed slurry. With good homogeneity in green sheet from well-dispersed slurry, isotropic shrinkage is thought to have occurred along the distance from center to edges of specimen during sintering.

Computer Simulation of Three Dimensional Particle Packing (콜로이드 입자의 3차원적인 적층에 대한 컴퓨터 시뮬레이션)

  • ;David M. Martin
    • Journal of the Korean Ceramic Society
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    • v.34 no.9
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    • pp.979-985
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    • 1997
  • The three-dimensional particle packing process is simulated using Lahey FORTRAN 90 as a programming language running on a personal computer. Particle clusters constructed with rearrangement which occurs during packing have higher average coordination number and packing density than particle clusters rearranged after packing. Rearranging particles can not completely block other particles from entering pore volume in 3-dimensional packing unlike in 2-dimensional packing. It is found that there is a region of instability where lower packing density results from the destruction of the ordered packing.

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Prediction of Packing Density of Milled Powder Based on Packing Simulation and Particle Shape Analysis

  • Amano, Yuto;Itoh, Takashi;Terao, Hoshiaki;Kanetake, Naoyuki
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • pp.1254-1255
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    • 2006
  • For precise property control of sintered products, it is important to understand accurately the packing density of the powder. We developed a packing simulation program that could make a packed bed of spherical particles having particle size distribution. In addition, the influence of the particle shape of the actual powder on the packing density was quantitatively analyzed. The predicted packing densities corresponded well to the actual data.

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Pressure-infiltration of Fe3O4-nanoparticles Into Porous Silicon and a Packing Density Monitoring Technique (다공성실리콘내 Fe3O4 나노입자의 압력침착과 채움밀도 모니터링 방법)

  • Lee, Joo Hyeon;Lee, Jae Joon;Lee, Ki Won
    • Journal of Sensor Science and Technology
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    • v.24 no.6
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    • pp.385-391
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    • 2015
  • In this paper, we propose a new method to infiltrate $Fe_3O_4$-nanoparticles into a porous silicon film and a monitoring technique to detect packing density of nanoparticles within the film. Recently, research to use porous silicon as a drug carrier or a new functional sensor material by infiltrating $Fe_3O_4$-nanoparticles has been extensively performed. However, it is still necessary to enhance the packing density and to develop a monitoring technique to detect the packing density in real time. In this light, we forcibly injected a nanoparticle solution into a rugate-structured free-standing porous silicon (FPS) film by applying a pressure difference between the two sides of the film. We found that the packing density by the pressure-infiltration method proposed in this paper is enhanced, relative to that by the previous diffusion method. Moreover, a continuous shift in wavelength of the rugate reflectance peak measured from the film surface was observed while the nanoparticle solution was being injected. By exploiting this phenomenon, we could qualitatively monitor the packing density of $Fe_3O_4$-nanoparticles within the FPS film with the injection volume of the nanoparticle solution.

Software Development for the Analysis and Prediction of Packing Density of Multi-sized Mixture Particles (Multi-sized 혼합입자의 충전 분율 해석 및 예측을 위한 소프트웨어 개발)

  • Oh, Min;Hong, Seong Uk
    • Applied Chemistry for Engineering
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    • v.18 no.6
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    • pp.636-642
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    • 2007
  • Software program to predict the packing density of multi-sized and multi-component particulate system was developed. For this purpose, the experiment to measure the packing density of AP (ammonium perchlorate) and Al (aluminum) particles with different sizes and their mixtures was carried out. The packing densities obtained from various experiments were compared with the predicted data from the developed software program. In the case of the packing density of the binary system, which is comprised of two different size particles and/or two different components, the relative errors were ranged 0.25~13.13%, and in the same venue the relative errors of the ternary system were 0.25~13.13%. Agreement between experimental data and the predicted results is reasonably accurate. In order to achieve the targeted packing density, the software program calculated the contour of the component particles and this will contribute the formulation of optimal packing systems.

The Variation of Packing Density According to Powder Size Distribution and Epoxy Resin in Soft Magnetic Composite (연자성 복합체에서 파우더 크기 분포와 Epoxy Resin에 따른 Packing Density 변화)

  • Lee, Chang Hyun;Oh, Sea Moon;Shin, Hyo Soon;Yeo, Dong Hun;Kim, Jin Ho
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.30 no.12
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    • pp.782-787
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    • 2017
  • There is growing interest in power inductors in which metal soft magnetic powder and epoxy resin are combined. In this field, the process technology for increasing the packing density of magnetic particles in an injection molding process is very important. However, little research has been reported in this regard. In order to improve the packing density, we investigated and compared the sedimentation heights of pastes for three types of soft magnetic alloy powders as a function of the mixing ratios and the type of resin used. Experimental results showed that the packing density was the highest (71.74%) when the mixing ratio was 80 : 16 : 4 (Sendust : Fe-S : CIP) according to the particle size using an SE-4125 resin. In addition, the packing density was found to be inversely related to the layer separation distance. As a result, it was confirmed that the dispersion of solid particles in the paste was important for curing; however, the duration of the curing process can greatly affect the packing density of the final composite.

The Physical Properties and Warmth retaining of Bedspread Jacquard Fabrics Using Filling Batt Yarn (충전 솜사를 이용한 Bedspread Jaquard 직물의 물성과 보온성)

  • Park, Myung-Soo
    • Fashion & Textile Research Journal
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    • v.9 no.4
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    • pp.445-449
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    • 2007
  • The results of warmth retaining, heat transfer and compressive elastic recovery of the five kinds of bedspread fabrics, which were produced from packing weft of 2700 denier and 3600 denier batt yarn treated with raw material of Polyester $150^D$/48 DTY, are as follows: 1) 3600 denier packing weft showed lover count in compressive elastic recovery than 2700d packing weft, so it took longer time to recover. 2) When packing weft of the same count is used, a sample of packing weft with higher density showed lower recovery. 3) It took 2700d packing weft 30min to get approximately 98% recovery in temperature $30^{\circ}C$. But, 3600d packing weft stayed under 98% recovery in the same temperature. Considering only the result of compressive elastic recovery, we should use 2700d packing weft. 4) The higher the density of packing weft is, the higher warmth retaining becomes. Although sharp increase appeared until 5min, equilibrium was kept without any increase after that time. 5) When 2700d packing weft was used, the maximum warmth retaining was approximately 60% and 64% in the conditions of density 12(thread/in) and 22(thread/in) respectively.

Packing density and filling effect of limestone fines

  • Kwan, A.K.H.;McKinley, M.
    • Advances in concrete construction
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    • v.2 no.3
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    • pp.209-227
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    • 2014
  • The use of limestone fines (LF) in mortar and concrete can in certain ways improve performance and thus has become more and more commonplace. However, although LF is generally regarded as a filler, it is up to now not clear how much filling effect it could have and how best the filling effect could be utilized. Herein, the packing density and filling effect of LF were studied by measuring the packing densities of LF, (LF + cement) blends and (LF + cement + fine aggregate) blends under dry and wet conditions, and measuring the performance of mortars made with various amounts of LF added. It was found that the addition of LF would not significantly increase the packing density of (LF + cement) blends but would fill into the paste to increase the paste volume and paste film thickness, and improve the flow spread and strength of mortar.

High Density Cell Cultivation of Escherichia coli in a Dual Hollow Fiber Bioreactor (이중실관 반응기에서 E. coli의 고농도 배양)

  • Chung, Bong-Hyun;Chang, Ho-Nam;Kim, In-Ho
    • Microbiology and Biotechnology Letters
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    • v.13 no.3
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    • pp.209-212
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    • 1985
  • The cell density and packing characteristics of Escherichia coli immobilized in a dual hollow fiber bioreactor consisting of outer silicone membrane for oxygen transport and three inner isotropic polypropylene hollow fibers for substrate transport were investigated. The cells have grown forming the layer like animal tissue in a nearly 100% packing density. The dry biomass density was 550g/liter of void volume for cell growth, which was the highest among the biomass densities ever reported.

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Packing of Alumina Particles in 3D Preform of Mullite Fiber by Slurry Pressure-Infiltration (슬러리 가압함침에 의한 3D Mullite 섬유 Preform의 알루미나 입자 충전)

  • Sim, Soo-Man
    • Journal of the Korean Ceramic Society
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    • v.50 no.6
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    • pp.528-532
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    • 2013
  • Well-dispersed slurries of submicron-sized alumina powders were pressure-infiltrated in 3D preforms of mullite fibers and the effects of the particle size and infiltration pressure on the particle packing characteristics were investigated. Infiltration without pressure showed that the packing density increased as the particle size decreased due to the reduction of the friction between the particles and the fibers. The infiltrated preforms contained large pores in the large voids between the fiber tows and small pores in the narrow voids between the individual fibers. Pressure infiltration resulted in a packing density of 77% regardless of the particle size or the infiltration pressure(210 ~ 620 kPa). Pressure infiltration shortened the infiltration time and eliminated the large pores in preforms infiltrated with the slurries of smaller particles. The slurry pressure-infiltration process is thus an efficient method for the packing of matrix materials in various preforms.