• Title, Summary, Keyword: Filler

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Dielectric Properties with Filler Heat Treatment in PCB for Embedded Capacitor (Embedded Capacitor용 PCB에서 filler 열처리에 따른 유전특성)

  • Lee, Ji-Ae;Shin, Hyo-Soon;Yeo, Dong-Hun;Kim, Jong-Hee;Yoon, Ho-Gyu
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.270-270
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    • 2007
  • 전자 산업의 발달로 인해 전자기기에 소형화, 경량화 및 다기능화가 요구되면서 민쇄회로기판(PCB)에도 고밀도화, 고집적회가 필요하게 되었다. 이에 따라 embedded passive 기술을 이용하여 기판 내부에 가능한 많은 수동소자들을 실장시키려는 노력이 진행되어지고 있다. 가장 수요가 많은 capacitor의 경우 부피와 전기적 특성 측면에서 내장 효과가 가장 큰 passive 소자에 해당한다. 본 연구에서는 내장형 capacitor의 유전재료로서 중요한 $BaTiO_3$ powder를 filler로 사용하여 epoxy/BT 복합체에서 filler의 분율에 따른 유전상수률 측정하고, filler의 열처리에 따른 유전상수의 변화를 관찰하였다. 그러고 이들 복합체의 mixing rule과 미세구조 관찰을 통하여 기판용 RCC 소재로서의 적용성을 평가하고자 하였다.

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Performance Characteristics of Small Sized Cross-flow Cooling Tower (소형 직교류형 냉각탑의 성능 특성에 관한 연구)

  • Sarker, M.M.A.;Kim, E.P.;Kim, J.D.;Jun, C.H.;Moon, C.G.;Yoon, J.I.
    • Journal of Power System Engineering
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    • v.9 no.2
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    • pp.93-98
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    • 2005
  • The performance of cooling tower is dependent on the thermal performance of the packings. It's assessed by heat transfer rate and fan power. In this study, new packing was developed for application in compact type cross-flow cooling tower. The packing characteristic curve and the pressure drop curve were obtained by measuring packing characteristic values and pressure drops of small sized filler in comparison to existing mid-large sized filler. The heat transfer characteristics on small sized filler are about 66% higher than existing mid-large sized filler. The pressure drop characteristics on small sized filler are about two times of the pressure drop characteristics on existing mid-large sized filler.

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Carbide Ceramics from Active-Filler-Controlled Pyrolysis in $CH_4$ Atmosphere

  • Kang, Keon-Taek;Kim, Deug-Joong;Annette Kaindl;Peter Greil
    • Journal of Korean Powder Metallurgy Institute
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    • v.6 no.4
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    • pp.320-324
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    • 1999
  • The formation, microstructure and properties of novel ceramic composite materials manufactured by active-filler-controlled polymer pyrolysis were investigated. In the presence of active filler particles such as transition metals, bulk components of various geometry could be fabricated from siliconorganic polymer. Molybdenum- and tungsten-filled polymer suspensions were prepared and their conversion to ceramic composites by annealing in $CH_4$ atmosphere were studied. Dimensional change. porosity and phase distribution (filler network) were analyzed and correlated to the resulting hardness values. Molybdenum and tungsten as active filler were carburized completely to $Mo_2C$, $W_2C$ and WC in $CH_4$ atmosphere. Consequently, microcrystalline composites with the filler reaction products embedded in a silicon oxycarbide glass matrix were formed. Hardness was increased with increasing carburization and reached 8.6-9.5 GPa in the specimen pyrolyzed in $CH_4$ atmosphere.

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The Effect of Ti and Sn Contents on the Shear Bonding Strength of Brazing Joint of YSZ to STS430 using Ag Based Filler Metals (Ag계 Filler Metal을 사용한 YSZ와 STS430의 브레이징 접합시 Ti, Sn의 함량 변화가 접합강도에 미치는 영향)

  • Lee, Ki Young;Park, Hyun Gyoon
    • Journal of Welding and Joining
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    • v.32 no.1
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    • pp.66-70
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    • 2014
  • In Ti active brazing of YSZ to STS 430 using Ag-Cu Filler Metal, the effect of Ti contents on the shear bonding strength were investigated together with the effect of brazing temperature and holding time. The addition of Ti in Ag-Cu Filler Metal increased the bonding strength up to 4.68% Ti, followed by the decrease with further addition. This seems to be caused by formation of TixOy at the reaction layer. Brazing temperature was optimized at $960^{\circ}C$ among a given temperature ranges. The addion of Sn to Ag-Cu filler metal brought the decrease of its melting temperature its melting temperature without a significant decrease of bonging strength.

Electrical properties of polyethylene composite films filled with nickel powder and short carbon fiber hybrid filler

  • Mironov, V.S.;Kim, Seong Yun;Park, Min
    • Carbon letters
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    • v.14 no.2
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    • pp.105-109
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    • 2013
  • Effects of the amount of nickel powder (Ni) in Ni-carbon fiber (CF) hybrid filler systems on the conductivity(or resistivity) and thermal coefficient of resistance (TCR) of filled high density polyethylene were studied. Increases of the resistivity and TCR with increasing Ni concentration at a given hybrid filler content were observed. Using the fiber contact model, we showed that the main role of Ni in the hybrid filler system is to decrease the interfiber contact resistance when Ni concentration is less than the threshold point. The formation of structural defects leading to reduced reinforcing effect resulted in both a reduction of strength and an increase of the coefficient of thermal expansion in the composite film; these changes are responsible for the increases of both resistivity and TCR with increasing Ni concentration in the hybrid filler system.

Nanofiller as Crosslinker for Halogen-Containing Elastomers

  • Sahoo, N.G.;Kumar, E.Shiva;Das, C.K.;Panda, A.B.;Pramanik, P.
    • Macromolecular Research
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    • v.11 no.6
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    • pp.506-510
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    • 2003
  • A Zn ion-coated nanosilica filler has been developed and tested, in chlorosulfonated polyethylene (CSPE) and polychloroprene (CR), as a vulcanizing activator, cum was reinforcing filler. In this study, ZnO was replaced by the Zn ion-coated nanosilica filler with an aim of studying the dual role of this nanofiller in CSPE and CR. In the case of CSPE vulcanizates, the presence of MgO deteriorated the state and rate of cure when the Zn ion-coated nanosilica filler was used, but in the case of CR it improved the state of cure and enhanced the modulus and tensile strength. The Zn ion-coated filler proved to be a better reinforcing-cum-curing agent than was externally added ZnO and NA-22 also proved to be a better curative in the presence of the Zn ion-coated nanosilica filler for both CSPE and CR.

A New Model to Predict Effective Elastic Constants of Composites with Spherical Fillers

  • Kim, Jung-Yun;Lee, Jae-Kon
    • Journal of Mechanical Science and Technology
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    • v.20 no.11
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    • pp.1891-1897
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    • 2006
  • In this study, a new model to predict the effective elastic constants of composites with spherical fillers is proposed. The original Eshelby model is extended to a finite filler volume fraction without using Mori-Tanaka's mean field approach. When single filler is embedded in the matrix, the effective elastic constants of the composite are computed. The composite is in turn considered as a new matrix, where new single filler is again embedded in the matrix. The predicted results by the present model with a series of embedding procedures are compared with those by Mori-Tanaka, self-consistent, and generalized self-consistent models. It is revealed through parametric studies such as stiffness ratio of the filler to the matrix and filler volume fraction that the present model gives more accurate predictions than Mori-Tanaka model without using the complicated numerical scheme used in self-consistent and generalized self-consistent models.

Thermal Conductivity and Mechanical Properties of Magnesium Oxide Reinforced Polyamide-66 Composites

  • Hwang, Seok-Ho
    • Elastomers and Composites
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    • v.50 no.3
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    • pp.205-209
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    • 2015
  • Magnesium oxide (MgO) reinforced polyamide-66 (PA66) composites were prepared through melt-compounding method in order to determine the possibility of using MgO particle as conductive filler in the polymer-based composite. The effects of MgO filler content on the thermal conductivity and mechanical properties for the PA66/MgO composites were investigated. The results showed that the addition of MgO filler to the PA66 matrix led to a large increase in thermal conductivity of the PA66/MgO composites. Tensile strengths of the PA66/MgO composites were slightly decreased as MgO filler loading increased. However, flexural strength and flexural modulus were improved with increasing filler loading. Notched Izod impact strengths were dramatically lowered by the addition of MgO filler.

The Method to Select the Optimal Particle Size of Earth by Optimum Micro-filler (최밀충전에 의한 흙의 적정입도 선정 방법)

  • Hwang, Hey Zoo;Kang, Nam Yi
    • KIEAE Journal
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    • v.13 no.6
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    • pp.137-143
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    • 2013
  • The purpose of this study is to suggest optimum micro-filler experiment method to select the optimal particle size of earth for using in earth construction works and test this suggestion through compressive strength measurement. According to the results of selecting the method to choose the optimum micro-filler mixing of earth and sand, three-stage filling(plate tamping) showed relatively high results and so was estimated to be the proper filling method. According to the results of optimum micro-filler experiment of earth and sand by the maximal sizes of sand, between 80% and 90% showed the highest result values. The larger the maximum size of sand was, the lower the addition ratio of sand was in optimum micro-filler mixing. According to the results of compressive strength experiment by the particle sizes of earth and sand, 90% in the addition ratio of sand showed the highest results, and so tended to be similar to the results of unit volume weight experiment.

Skin Necrosis with Oculomotor Nerve Palsy Due to a Hyaluronic Acid Filler Injection

  • Lee, Jae Il;Kang, Seok Joo;Sun, Hook
    • Archives of Plastic Surgery
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    • v.44 no.4
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    • pp.340-343
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    • 2017
  • Performing rhinoplasty using filler injections, which improve facial wrinkles or soft tissues, is relatively inexpensive. However, intravascular filler injections can cause severe complications, such as skin necrosis and visual loss. We describe a case of blepharoptosis and skin necrosis caused by augmentation rhinoplasty and we discuss the patient's clinical progress. We describe the case of a 25-year-old female patient who experienced severe pain, blepharoptosis, and decreased visual acuity immediately after receiving a filler injection. Our case suggests that surgeons should be aware of nasal vascularity before performing an operation, and that they should avoid injecting fillers at a high pressure and/or in excessive amounts. Additionally, filler injections should be stopped if the patient complains of severe pain, and appropriate measures should be taken to prevent complications caused by intravascular filler injections.