• Title/Summary/Keyword: Glass melting

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Improved Field Emission Currents of Carbon Nanotubes after Laser Irradiation

  • Lee, Jung-Woo;Park, Jae-Hong;Yi, Whi-Kun
    • Bulletin of the Korean Chemical Society
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    • v.27 no.10
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    • pp.1651-1654
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    • 2006
  • Field emission (FE) currents were measured for silver-pasted and glass-pasted single-walled carbon nanotubes (SWNTs) after illuminating the tubes with a pulsed 532 nm laser. A very low turn-on field of approximately 0.4 V/m m and a high current density ~1700 $\mu A/cm^2$ at 3.5 V/m m was obtained for the silver-pasted SWNTs after laser irradiation but on the whole, no improvements were found for the glass-pasted SWNTs. Two roles of laser irradiation for the silver-pasted SWNTs were proposed. First, the embedded SWNTs and SWNT bundles inside the silver paste were immerged on the outer surface due to an instantaneous melting or annealing of the silver metals by the laser resulting in an increase of the field emission sites. Second, the laser irradiation was thought to improve the electrical contact between SWNTs and the silver metal by reducing the contact resistance via laser-induced thermal annealing, which was responsible for increasing the FE currents.

A Fault Diagnosis System of Glass Melting Furnace Using A Fuzzy Expert System (퍼지 전문가 시스템을 이용한 유리 용해로 이상 감시 시스템 구축 사례)

    • Journal of Intelligence and Information Systems
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    • v.8 no.1
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    • pp.65-65
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    • 2002
  • 본 논문에서는 용해로 이상감시를 위한 실시간 유리 용해로 운전 전문가시스템을 구축한 결과를 소개한다. 유리 용해 공정에서는 운전자의 경험지식에 의해 내부의 상황을 판단하게 되고, 이는 용해로 수명과 제품의 품질에 중요한 영향을 준다. 이를 전문가 시스템으로 구현하기 위하여, 먼저 기존 운전자의 지식을 취합, 분석한다. 그 후,취합된 각 지식들의 특성에 부합하도록 이진 규칙(Crisp Rule)과 퍼지 규칙(Fuzzy Rule)으로 구분한다. 이 때, 선형 회귀분석을 통하여 퍼지 규칙의 입력을 결정함으로써 보다 정확한 운전 지식의 표현이 가능하도록 하였다. 설계된 알고리듬은 젠심(Gensym)사의 실시간 전문가 시스템 개발 툴인 G2를 사용하여 구현하였다. 제시된 퍼지 전문가 시스템은 삼성코닝(주) 수원사업장의 실제 생산 용해 공정에 직접 적용하여 그 효율성이 검증되었다.

A Study on Electric Conduction Characteristic in the Glass Transition Point of electric Power Equipments Cross - Linked Polyethylene (전력설비용 가교 Polyethlene의 Glass 전이점에서의 전기전도 특성에 관한 연구)

  • 김강원;서장수;김병인;국상훈
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 1991.10a
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    • pp.64-68
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    • 1991
  • It happened that there was a sudden peak with the capacity of change, when I measured the capacity of change, cubical expansion and Thermally Stimulated Current on the Cross - Linked Polythylene. Crystal melting began at 375 K and changed into formaless shapeless at 380 K. The conduct of a particle on the surfase of dipole, electron trap was founded to be ion conduction nature under the low electronic field, wherase, the electron nature under the high electronic field. Consequentity, under the semi-conduction layer electronic a particle was injected to inter-fase and accumulated for a time and appeared to be TSC.

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Compound waterproofing method of green roof using copper barrier sheet and recycled tire melting liquid waterproofing material that reinforced treatments are valve and glass fiber mesh. (알루미늄 판막과 유리섬유를 합지한 구리방근시트와 폐타이어 용융액상 도막방수재를 이용한 옥상녹화 복합방수공법)

  • Kim, Young chan;Cho, Il Kyu;choi, sung min;Oh, Sang Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2008.11a
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    • pp.173-178
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    • 2008
  • This is green roof bottom system which composed by aluminum valve and glass fiber together as major reinforcement, so the cooper sheet can have root proof, and using recycled tire gel-type membrane waterproofing system which dost not contains VOCs. The copper sheet reduce the plants' root growing, so it helpes to maintain the waterproofing layer and stability of root proofing. Gel type membrane waterproofing system can do waterproofing, stress dispersion, and reducing leakage expansion. So those two materials can help each other to make green roof bottom layer would have the stability and durability.

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Possible Glass Systems for Non-Pb Dielectric Layers, Barrier Rib and Sealant in PDP

  • Kim, Hyung-Sun;Jung, Byung-Hae
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.391-394
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    • 2003
  • It is inevitable that reconsideration of the use of lead oxides in the electronics industry be undertaken as long as detrimental effects to the environment remain. To solve this problem, many recent studies on Pb-free compositions for PDP (plasma display panel) dielectric layers and also sealing glass compositions have been made. The present study was conducted to investigate whether the alternative systems for leadfree low firing glasses, detailed below, are available for use in PDP materials. The results suggest that low-melting phosphate glasses would be suitable as an alternative material for the Pb-based dielectric layer, sealants and barrier ribs in PDP.

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Ultraprecision Machining of Glassy Carbon (Glassy Carbon의 초정밀 가공)

  • Hwang, Yeon;Lee, Hyeon-Sung;Kim, Hye-Jeong;Kim, Jeong-Ho
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.11 no.3
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    • pp.19-23
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    • 2012
  • Glassy carbon is widely used for high temperature melting process such as quartz due to its thermal stability. For utilizing Classy Carbon to glass mold press(GMP) optical lens, brittleness of Glassy Carbon is main obstacle of ultraprecision machining. Thus authors investigated ductile machining of Glassy Carbon adopting turning and grinding process respectively. From the experiments, ultraprecision turning surfaces resulted brittle crack in all machining conditions and ultraprecision grinding surfaces showed semi-ductile mode in small undeformed chip thickness conditions.

A Study on the YAG Laser Machining of Cr Thin Films (YAG 레이저에 의한 Cr박막가공에 관한 연구)

  • 강형식;홍성준;박홍식;전태옥
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.1053-1057
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    • 1997
  • Laser thin film process with a Q-switch pulsed YAG laser was performed for micro machining. In this research, we performed basic Cr thin film on glass substrates removal machining experiments. Form experiments, it happens not only evaporration of thin film but also spatter and cohesion of melting substance in working region, when machining a Cr thin film by Q-switch YAG laser beam irradiation. Critical energy of surface irradiation type by irradiation direction of laser in a face composing thin film on the glass is higher than that of back irradiation type, but the latter is favorable because of spatter appearance. In case of image formation position when laser beam is irradiated, the defocus is permitted to a certain extent within forcus depth. Ifexceeds focus depth, formation of pattern is vanishing step by step.

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Fabrication of Low Temperature Cofired Ceramic (LTCC) Chip Couplers for High Frequencies ; II. Effect of Sintering Process on Ag Diffusion (고주파용 저온 동시소성 세라믹(LTCC)칩 커플러 제조: II. Ag 이온 확산에 대한 소결공정의 영향)

  • 이선우;김경훈;심광보;구기덕
    • Journal of the Korean Ceramic Society
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    • v.36 no.5
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    • pp.490-496
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    • 1999
  • The sintering behavior of LTCC (low temperature cofired ceramics) chip couplers was investigated in relation with Ag diffusion at the interface of glass ceramic substrate-Ag electrode. Sintering temperature was in the range of 825$^{\circ}C$-975$^{\circ}C$. The commercial green sheet and silver electrode were used. Below 875$^{\circ}C$ the diffusion of the Ag ion into the substrate and the penetration of glassy phases into the electrode occurred due to an increase of fluidity. Thus the lectrode line was severely deformed and damaged. At 975$^{\circ}C$ the transformation of crystalline phases into glassy phases and the melting of the Ag electrode resulted in the diffusion of the considerable amount of Ag ions.

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The Fabrication of Low Temperature Firing Substrate of $Li_2O-MgO-MgF_2-SiO_2-B_2O_3$ system

  • Park, Jung-Houn;Park, Dae-Hyun;Kang, Won-Ho
    • Journal of the Microelectronics and Packaging Society
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    • v.6 no.4
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    • pp.35-39
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    • 1999
  • The $Li_2O-MgO-MgF_2-SiO_2$glasses with addition of $B_2O_3$ were investigated in order to make glass-ceramics for low temperature firing substrate. Glasses were made by melting at $1450^{\circ}C$ in the electronic furnace and crystallized at $750^{\circ}C$. The crystal phases were polycrystalline of lithium boron fluorphlogopite and lithium fluorhectorite. The crystal shape was chanced to granule type from needle type with increasing $B_2O_3$ content. Average particle size of the glass-ceramics after water swelling was 3.77$\mu\textrm{m}$. The optimum sintering temperature and sintering shrinkage of the substrate were $900^{\circ}C$ and 13.4%, respectively.

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Preparation and properties of BaO-ZnO-$B_2O_3-V_2O_5$ glass for PDP dielectric paste (PDP 유전체용 BaO-ZnO-$B_2O_3-V_2O_5$ 유리의 제조 및 특성 변화)

  • Son, Myung-Mo;Lee, Sang-Geun;Park, Hee-Chan
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.05c
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    • pp.295-298
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    • 2003
  • The principal problems in development of dielectric paste materials for PDP(plasma display panel)are PbO free paste and low melting temperature. We prepared PbO free paste from glasses in the system BaO-ZnO-$B_2O_3-V_2O_5$. DTA, XRD and SEM were used to study and characterize BaO-ZnO-$B_2O_3-V_2O_5$ glasses. PbO free paste developed at this paper has thermal expansion of $74{\times}10^{-7}/^{\circ}C$, DTA transformation point of $460^{\circ}C$, and firing condition of $560^{\circ}C$, 10min.

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