• Title/Summary/Keyword: flat membrane

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A Research on Organic Electro-luminescence (유기 전기발광 소자에 관한 연구)

  • Lee, Han-Seong
    • Proceedings of the KIEE Conference
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    • 2005.10a
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    • pp.82-85
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    • 2005
  • Organic EL has been expected to adopt to a new styles of technology that make flat display after Tang & Vanslyke made good electric luminescence device in late 1980s. Their studies based on multi layer structure that consists of emitting layer and carrier transporting layer using proper organic material. In this study, we made multi layer device using $Eu(TTA)_3(phen)$ as a luminescence material by PVD and investigate luminous properties of each device. But oxidization of organic layer by ITO, energy walls in both pole interface, contaminations of ITO surface, importance of protecting membrane, diffusive dimming of light to cathode organic layer, these causes of degradations are common facts of a macromolecule and micromolecule. We think these degradation caused by the impact of heat and electro-chemical factor, bulk effect and interface phenomenon, and raise a question.

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A study on Fabrication and Characterization of Organic Light-Emitting Diodes (유기 발광 다이오드의 제작 및 특성에 관한 연구)

  • Lee, Han-Seong
    • Proceedings of the KIEE Conference
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    • 2008.11b
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    • pp.89-91
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    • 2008
  • Organic EL has been expected to adopt to a new styles of technology that make flat display after Tang & Vanslyke made good electric luminescence device in late 1980s. Their studies based on multi layer structure that consists of emitting layer and carrier transporting layer using proper organic material. But oxidization of organic layer by ITO, energy walls in both pole interface, contaminations of ITO surface, importance of protecting membrane, diffusive dimming of light to cathode organic layer, these causes of degradations are common facts of a macromolecule and micro molecule. We think these degradation caused by the impact of heat and electro-chemical factor, bulk effect and interface phenomenon, and raise a question.

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A Research on Life of Organic Lumminescence Devices (유기EL 소자의 수명에 관한 연구)

  • Lee, Han-Sung
    • Proceedings of the KIEE Conference
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    • 2002.06a
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    • pp.110-113
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    • 2002
  • Organic EL has been expected to adopt to a new styles of technology that make flat display after Tang & Vanslyke made good electric luminescence device in late 1980s. Their studies based on multi layer structure that consists of emitting layer and carrier transporting layer using proper organic material. In this study. we made multi layer device using $Eu(TTA)_3(phen)$ as a luminescence material by PVD and investigate luminous properties of each device. But oxidization of organic layer by ITO. energy walls in both pole interface. contaminations of ITO surface, importance of protecting membrane, diffusive dimming of light to cathode organic layer. these causes of degradations are common facts of a macromolecule and micromolecule. We think these degradation caused by the impact of heat and electro-chemical factor, bulk effect and interface phenomenon. and raise a question.

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Magnetic Orientations of Bull Sperm Separated into Head and Flagellum Treated by DTT or Heparin

  • Suga, D.;Shinjo, A.;Kurnianto, E.;Nakada, T.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.2
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    • pp.167-175
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    • 2000
  • This paper describes the magnetic orientation of bull sperm separated into the head and the flagellum treated by DTT or heparin in a 5,400G static field. Semen samples collected from four bulls (Japanese Black) were mixed to the same sperm density. One percentage triton X-100 was used to extract the plasma membrane. The intact and demembranated sperm suspensions were treated with 20, 200, 2,000 mM DTT, 100, 1,000 or 10,000 units heparin solutions at $4^{\circ}C$ for 6 days. The decondensation of the sperm nuclei treated by DTT or heparin was examined by measuring the head area at 1, 3 and 6 days. After measuring the area, each sample was exposed to a 5,400G static magnetic field generated by Nd-Fe-B permanent magnets for 24 hours at room temperature. Results showed that the sperms were separated into the head and the flagellum through the DTT treatment. Almost of the separated heads showed that their long axis oriented perpendicularly to the magnetic lines of force, and most of the long axis perpendicularly oriented heads showed that their flat plane oriented perpendicularly in a 5,400G magnetic field. Also, the demembranation of the head tended to increase those perpendicular orientations, while those perpendicular orientations of the head declined with the decondensation of the sperm nuclei. These findings suggest that strong magnetic anisotropy for the perpendicular orientation of the long axis and the flat plane of the head occurs in the sperm nuclei in a 5,400G magnetic field. The separated flagellum showed lower parallel orientation, and the separated and demembranated flagellum showed parallel orientation to the magnetic lines of force in this magnetic field. These findings suggest that weak magnetic anisotropy of the parallel orientation of the flagellum occurs in the inside components in a 5,400G field.

Fabrication of Stress-balanced $Si_{3}N_{4}/SiO_{2}/Si_{3}N_{4}$ Dielectric Membrane (스트레스균형이 이루어진 $Si_{3}N_{4}/SiO_{2}/Si_{3}N_{4}$ 유전체 멤브레인의 제작)

  • Kim, Myung-Gyoo;Park, Dong-Soo;Kim, Chang-Won;Kim, Jin-Sup;Lee, Jung-Hee;Lee, Jong-Hyun;Sohn, Byung-Ki
    • Journal of Sensor Science and Technology
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    • v.4 no.3
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    • pp.51-59
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    • 1995
  • Stress-balanced flat 150 nm-$Si_{3}N_{4}$/300 nm-$SiO_{2}$/150 nm-$Si_{3}N_{4}$ dielectric membrane on silicon substrate has been fabricated. Analyses of stress-deflection and stress-temperature, and visual inspection for the strain diagnostic test patterns were performed in order to characterize stress properties of the membrane. The $SiO_{2}$ layers sandwiched between two $Si_{3}N_{4}$ layers were deposited by three different techniques(PECVD, LPCVD, and APCVD) for the purpose of investigating the dependence of stress on the deposition methods. Some extent of tensile stress in the membrane was always observed regardless of the deposition methods, however it could be balanced against silicon substrate by post-wet oxidation in $1,150^{\circ}C$. Stress-temperature characteristics of the membranes showed that APCVD-LTO was better as mid-$SiO_{2}$ layer than PECVD - or LPCVD - $SiO_{2}$ when there was no oxidation process.

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Permeation Properties of Single Gases ($N_2$, $O_2$, $SF_6$, $CF_4$) through PDMS and PEBAX Membranes (PDMS와 PEBAX 분리막을 통한 단일기체($N_2$, $O_2$, $SF_6$, $CF_4$) 투과 특성)

  • Kim, Hanbyul;Lee, Minwoo;Park, Wankeun;Lee, Soonjae;Lee, Hyunkyung;Lee, Sanghyup
    • Membrane Journal
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    • v.22 no.3
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    • pp.201-207
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    • 2012
  • In this study, we investigated permeation of single gas ($N_2$, $O_2$, $CF_4$, and $SF_6$) through flat sheet membrane composed of PDMS (poly-dimethylsiloxane) and PEBAX (polyether block amides). Gas permeation experiment was performed with various feed pressure. Permeability was estimated using permeation flux measured by continuous-flow technique. The permeability of gases except $SF_6$ in PDMS were decreased with the upstream pressure increased. $SF_6$ is much more permeable than $CF_4$, which is due to higher critical temperature of $SF_6$. The permeability decreased in the following order: $O_2$ > $N_2$ > $SF_6$ > $CF_4$. On the other hand, the permeability of gases in PEBAX followed the order: $O_2$ > $N_2$ > $CF_4$ > $SF_6$ which are opposite of the order of kinematic diameter (${\AA}$)($SF_6$ > $CF_4$ > $N_2$ > $O_2$). The $SF_6/CF_4$ pure gas selectivity in PDMS was 2.1 at 0.7 MPa.

The Effect of Turbulence Promoters on the Mass Transfer in Ultrafiltration (한외여과에서의 물질전달에 대한 난류촉진물체의 영향)

  • Oh, Won-Suhk;Park, Ham-Yong;Lim, Gio-Bin;Kim, Woo-Sik
    • Membrane Journal
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    • v.4 no.4
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    • pp.221-231
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    • 1994
  • The GR51PP(MWCO 50,000) and GR40PP(MWCO 100,000) membranes manufactured by DDS were used in ultrafiltration of dextran(Mw. : 500,000) solution in flat plate ultrafiltration cell filled with various types of turbulence promoters. The flux improvement by using turbulence promoter was higher in laminar flow region than in turbulent flow region. The maximum improvements of permeate flux were foud as 112% and 50% I laminar flow region and turbulent flow region, respectively. Also, the solute rejection of the ultrafiltration membrane was improved by turbulence promoters and its effect was significant in the high transmembrane pressure and laminar flow region. The smaller the spacer mesh size was used, the higher the flux improved, but the pressure drop in ultrafiltration cell also increased. In laminar flow region, pressure drop by the spacer was negligible, but in turbulent flow region it changed significantly depending upon the mesh size of the spacer and therefore, its mesh size must be baken into account in the design of the process. The predicted results of the modified mass transfer correlation had better agreement with experimental results than those of unmodified one, The modified mass transfer correlations for laminar and turbulent flow region are shown as follow. $N_{sh}=0.151(N_{Re})^{0.199}(N_{Sc})^{0.22}(N_{Scm})^{0.197}\;(625 $N_{sh}=0.0165(N_{Re})^{0.428}(N_{Sc})^{0.33}(N_{Scm})^{0.223}\;(5015

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Structural Changes of PVDF Membranes by Phase Separation Control (상분리 조절에 의한 PVDF막의 구조 변화)

  • Lee, Semin;Kim, Sung Soo
    • Korean Chemical Engineering Research
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    • v.54 no.1
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    • pp.57-63
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    • 2016
  • Thermally induced phase separation (TIPS) and nonsolvent induced phase separation (NIPS) were simultaneously induced for the preparation of flat PVDF membranes. N-methyl-2-pyrrolidone (NMP) was used as a solvent and dibutyl-phthlate (DBP) was used as a diluent for PVDF. When PVDF was melt blended with NMP and DBP, crystallization temperature was lowered for TIPS and unstable region was expanded for NIPS. Ratio of solvent to diluent changed the phase separation mechanism to obtain the various membrane structures. Contact mode of dope solution with nonsolvent determined the dominant phase separation behavior. Since heat transfer rate was greater than mass transfer rate, surface structure was formed by NIPS and inner structure was by TIPS. Quenching temperature of dope solution also affected the phase separation mechanism and phase separation rate to result in the variation of structure.

An Effect of Surface Dashpot for KC-1 Basic Insulation System Under Sloshing Loads (슬로싱 하중을 받는 KC-1 단열시스템의 표면 완충 효과)

  • Jin, Kyo Kook;Yoon, Ihn Soo;Yang, Young Chul
    • Transactions of the KSME C: Technology and Education
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    • v.3 no.3
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    • pp.193-199
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    • 2015
  • Sloshing of LNG cargo can cause high impact loads on the supporting and containing structures. This is particularly critical for membrane-type tanks since these will have flat surfaces and corner regions which can lead to increased peak pressures for sloshing impacts. The membrane-type containment system is much more flexible compared to the steel hull structure. As a result, fluid-structure interaction plays an important role in the structural analysis of the containment system under sloshing load. This study is based on the direct calculation method of applying sloshing loads to the KC-1 basic insulation system using finite element analysis. The structural analysis of KC-1 basic insulation system considers the dashpot as fluid-structure interaction between liquid cargo and the LNG containment system. The maximum stress of the polyurethane form for KC-1 insulation system is 1.5 times lower than one without dashpot.

Fabrication of Micro-Heatsink using Nanotemplate (나노 템플레이트를 이용한 마이크로 히트 싱크)

  • 함은주;손원일;홍재민
    • Journal of the Microelectronics and Packaging Society
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    • v.10 no.1
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    • pp.7-11
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    • 2003
  • The semiconductor chips or electronic components generate heat, which causes malfunction of the parts when it was not cooled properly. Bulky heat sink and cooling fan are used to get rid of the heat. However, with this bulky system, it is hard to integrate the electronics system in a small scale. The cooling efficiency of the system depends on the surface area of the heat sink, thermal conductivity of the material and the method of integration. In order to develop a novel cooling system, a micro-heatsink with a large surface area while retaining small volume was fabricated by electroless deposition of gold/copper inside a Track-etched membrane. The structure of the micro-heatsink was investigated using SEM or optical microscope. It was also found that the micro-heatsink is more efficient than a flat copper plate.

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