• 제목/요약/키워드: Spacers

검색결과 250건 처리시간 0.023초

전력용 고온초전도 코일 모의전극계에서의 기포거동에 관한 연구 (Study on Bubble Behavior with the Simulated Electrode System of High Temperature Superconducting Coils for Electric Power System)

  • 석복렬;김종구
    • 한국초전도ㆍ저온공학회논문지
    • /
    • 제3권1호
    • /
    • pp.16-21
    • /
    • 2001
  • Bubble behavior is studied with an electrode system which consists of coaxial spiral coil-to-cylindrical electrode with an insulation barrier and spacers and is immersed in liquid nitrogen for simulation of insulation environments in high temperature superconducting(HTS) coils The results show that the bubble behavior Is affected severely by electric field: (1) under low applied voltage bubbles rise by buoyancy, but at higher applied voltage they are trapped in a lower electric field region below the coil electrode, and (2) the trapped bubble flows along the downside of coil electrode if no obstruction is in a groove between coil turns. but it splashes out of the groove after its growing if the obstruction such as spacer-exists.

  • PDF

Quantum Chemical Designing of Novel Organic Non-Linear Optical Compounds

  • Mahmood, Asif;Abdullah, Muhammad Imran;Nazar, Muhammad Faizan
    • Bulletin of the Korean Chemical Society
    • /
    • 제35권5호
    • /
    • pp.1391-1396
    • /
    • 2014
  • In the present study, ten metal free non-linear optical (NLO) compounds have been designed. These compounds have designed by structural modification of (2-cyano-5-(4-(phenyl(4-vinylphenyl)amino)phenyl) penta-2,4-dienoic acid (TC4). Density functional theory was used for structure optimization and determination of photo-physical properties. These compounds contain triphenylamine as electron-donor and cyanoacrylic acid as acceptor. Five ${\pi}$-spacers are used to connect the donor and acceptor. Two auxiliary donors are also used to assist the donor. Results of this study indicate that stronger electron-donating auxiliary groups and longer ${\pi}$-conjugation enhance NLO response. Major absorption peaks of all systems were in the visible region. These absorption peaks are associated with the ${\pi}-{\pi}^*$ transitions of the entire molecule. From calculations it is clear that all system will be good NLO material. The present calculations will provide new ways for experimentalists to synthesize high-performance NLO material.

Isolation and Identification of Fungi for Decolorization of Synthetic Dyes

  • Lee, Jang-Hoon;Nam, Youn-Ku;Kwon, Hyuk-Ku
    • 한국환경보건학회:학술대회논문집
    • /
    • 한국환경보건학회 2005년도 Proceedings of KSEH.Minamata Forum
    • /
    • pp.95-102
    • /
    • 2005
  • For decolorization of synthetic dyes, Isolate fungi were investigated for the decolorization of 8 industrial dyes. One fungus isolated from textile wastewater collected from Banweol industrial complex, Korea showed excellent ability for removing synthetic dyes. Internal Transcribed Spacers (ITS) sequencing result was confirmed as the new Basidomycetes species. HUE05-1 The optimal decolorizaton conditions were pH5, 30$^{\circ}C$ and aerobic condition. HUE05-1 was completely decolorized all dyes in both solid and liquid condition. The result is decolorization effect at Reactive Orange 16; 97.12%, Reactive Blue 19; 92.09%, Reactive Blue 49; 97.04%, Reactive Yellow 145; 95.53%, Acid Orange 10; 99.18%, Acid Violet 43; 98.73%, Acid Blue 350; 94.71%, Disperse Blue 106; 90.07%.

  • PDF

Scytalidium parasiticum sp. nov., a New Species Parasitizing on Ganoderma boninense Isolated from Oil Palm in Peninsular Malaysia

  • Goh, Yit Kheng;Goh, Teik Khiang;Marzuki, Nurul Fadhilah;Tung, Hun Jiat;Goh, You Keng;Goh, Kah Joo
    • Mycobiology
    • /
    • 제43권2호
    • /
    • pp.107-117
    • /
    • 2015
  • A mycoparasite, Scytalidium parasiticum sp. nov., isolated from the basidiomata of Ganoderma boninense causing basal stem rot of oil palm in Johor, Malaysia, is described and illustrated. It is distinct from other Scytalidium species in having smaller asci and ascospores (teleomorphic stage), longer arthroconidia (anamorphic stage), hyaline to yellowish chlamydospores, and producing a fluorescent pigment. The phylogenetic position of S. parasiticum was determined by sequence analyses of the internal transcribed spacers and the small-subunit ribosomal RNA gene regions. A key to identify Scytalidium species with teleomorphic stage is provided.

Dust Figure를 이용한 스페이서상의 대전전하 분포해석 (An Analysis on the Charge Distribution on the Spacer Using Dust Figure)

  • 최재구;서길수;김영배;김익수
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 1998년도 하계학술대회 논문집 E
    • /
    • pp.1681-1683
    • /
    • 1998
  • Unlike AC, DC dielectric characteristics of the spacer are very influenced by the quantity and the distribution of surface charges. A general impression of the distribution of surface charges is obtained if electrostatic powders are sprinkled over the surface. The distribution of surface charge was investigated with dust figures. Mechanism of charge accumulation on the spacer of $SF_6$ GIS has been studied using various types of model spacers which have different depths. As a result, it was found that charge accumulation was dominantly influenced by the normal component of the electric field and the usage of embedded electrodes was an adequate method to lessen field concentration around the triple junction. The guide of the optimum depth of the spacer was proposed.

  • PDF

소형 정밀 왕복동기기용 선형 탄성 베어링 모델(KIMM-LFB)의 설계 및 해석 (Design and analysis of a newly devised linear flexure bearing(KIMM-LFB) for small precision reciprocating machines)

  • 최상규;박성제;홍용주;김효봉
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2002년도 추계학술대회논문집
    • /
    • pp.404-409
    • /
    • 2002
  • A newly devised linear flexure bearing (KIMM-LFB) for reciprocating machines is disclosed having improved tight gas clearance maintaining capability for better system performance. KIMM-LFB is an integrated device comprising an axially moving diaphragm with circumferentially arranged arc-shaped flexure blades secured between rim and hub spacers, which turn out to have higher radial stiffness than the one with circumferential tangent cantilever flexure blades. It is expected for KIMM-LFB to play a key role in designing long life, special purpose reciprocating machines such as spacecraft borne cryogenic refrigerators (cryocoolers) by providing frictionless, non-wearing, linear movement and radial support for the machines as well as a gas clearance seal by maintaining extremely tight clearances between piston and cylinder.

  • PDF

Sequence Analysis of Cochlodinium polykrikoides Isolated from Korean Coastal Waters Using Sequences of Internal Transcribed Spacers and 5.8S rDNA

  • Kim, Hak-Gyoon;Cho, Yong-Chul;Cho, Eun-Seob
    • Journal of the korean society of oceanography
    • /
    • 제35권3호
    • /
    • pp.158-160
    • /
    • 2000
  • The relativity of four isolates of C. polykrikoides was determined by comparative sequence analysis based on direct sequencing of PCR amplified ribosomal DNA (the internal transcribed spacer region and the 5.8S rDNA). Sequence comparisons indicated that four isolates had the same nucleotide sites in the ITS regions, as well as a total of 585 nucleotide length and 100% homology. The molecular data revealed that C. polykrikoides in Korean coastal waters show no genetical difference.

  • PDF

Spiroacetal을 포함하는 신고분자의 합성(2) (Syntheses and Properties of New Polymers Containing Spiroacetal Moiety (2))

  • 이종문;최두진;이광섭;조순채;안종렬
    • 한국염색가공학회지
    • /
    • 제4권3호
    • /
    • pp.97-115
    • /
    • 1992
  • In order to improve the processability of rigid rod-like polyspiroacetals without significant loss of their good nature, in this work a few new ideas for molecular design were adopted: (1) Copolymerization for breaking the regularity of polymer repeating units. (2) Incorporation of flexible methylene linkages or spacers in rigid spiroacetal polymer main chain. (3) Derivatization of long flexible side chains onto rigid polymer backbone. On the basis of these ideas, a series of polyspiroacetals were prepared, using the phase transfer catalyst, BTMAC, by interfacial polymerization reactions of spiroacetal monomer (SAB) and disubstituted aromatic acid chlorides or aliphatic diacid chlorides. Physical properties of these polyspiroacetals are discussed in relation to their chemical structure and are compared with those of polyspiroacetals synthesized by several other researchers.

  • PDF

Etchingless Fabrication of Bi-level Microstructures for Liquid Crystal Displays on Plastic Substrates

  • Hong, Jong-Ho;Cho, Seong-Min;Kim, Yeun-Tae;Lee, Sin-Doo
    • Journal of Information Display
    • /
    • 제9권4호
    • /
    • pp.6-10
    • /
    • 2008
  • In this study, the selective-wettability-inscription (SWI) technique for the wet-etchingless fabrication of surface microstructures applicable to wide-viewing liquid crystal displays (LCDs) on plastic substrates was demonstrated. On the basis of the selective wetting of the photopolymer, the bi-level microstructures were spontaneously formed to serve as spacers for maintaining uniform cell gap and protrusions for the generation of multi-domains. The LC cell that has bi-level microstructures shows good extinction in the field-off state and a wide-viewing property in the field-on state. The SWI technique would be useful for the fabrication of flexible displays on plastic substrates.

SMES용 Model Coil의 특성시험 (Test of the Model Coil for a SMES)

  • 김해종;성기철;조전욱;권영길;류강식;류경우
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2001년도 하계학술대회 논문집 B
    • /
    • pp.726-728
    • /
    • 2001
  • For the development of a small-sized superconducting magnetic energy storage (SMES) system we designed, fabricated and tested the model coil consisting five coils with different features, e.g. winding tensions, bore diameters and materials, cooling channels. The results show that even in the highly pre-stressed small coil A, about 70 % of the coils critical current are degraded. The quench current of the coils A, B and E with narrow cooling channels is two times as high as that of the coil C without them though they are similar except spacers. The test results also indicate that the usual training effect depends on the winding tensions of the coils but the quench characteristic does not change according to materials of a bobbin.

  • PDF