• Title/Summary/Keyword: PTC

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Synthesis and Analysis of 6,6-dichlorobicyclo[3, 1, 0]hexane-3-carboxylic acid (6,6-Dichlorobicyclo[3, 1, 0]hexane-3-carboxylic acid의 합성과 분석)

  • Lee, Kwang-Soo;Yang, Jae-Kun
    • Analytical Science and Technology
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    • v.14 no.1
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    • pp.1-7
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    • 2001
  • 6,6-Dichlorobicyclo[3, 1, 0]hexane-3carboxylic acid was synthesized by dichlorocarbene addition into 3-cyclopentenecarboxylic acid using BTEA.Cl as phase transfer catalyst. $^1H$ NMR $^{13}C$ NMR data analyst showed that this compound had boat-like conformation and carboxyl group existed as trans form.

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The Breakdown voltage with Ti/Ba mole ratio on the PTC thermistor (PTC thermistor에서 Ti/Ba mole ratio에 따른 파괴전압)

  • Kim, B.S.;Lee, S.H.;Choi, C.S.;Shin, T.H.;Park, G.B.;Kim, C.S.;Kim, Y.H.;Lee, D.C.
    • Proceedings of the KIEE Conference
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    • 1998.07d
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    • pp.1493-1494
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    • 1998
  • We have investigated the influence of Ti/Ba mole ratio in the characteristics of the modified $BaTiO_3$ systems with Ca addition. The specimens were fabricated with variations in Ti/Ba mole ratio between 0.995 and 1.01, and sintered in the temperature range between $1325^{\circ}C$ and $1375^{\circ}C$. When Ti/Ba mole ratio was 1.005 and sintering temperature was $1350^{\circ}C$, the breakdown voltage shows 260[V /mm].

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Process and Properties of Sheet Type PTC Thermistor Bon Keup Koo Byung Don Kang Jin Gi Jung and Ho Gi Kim (Sheet형 PTC 서미스터의 제조 및 물성)

  • 강병돈
    • Journal of the Microelectronics and Packaging Society
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    • v.2 no.2
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    • pp.41-48
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    • 1995
  • 본 논문에서는 테이프 케스팅법으로 제조한 BaTiO3 계 쉬트형 PTCR 세라믹스의 적기적물성에 대하여 연구하였다. PTCR의 조성은 몰비로 89.9 BaTiO3-0.1Sb2O3-10 CaTiO3-0.05MnO3였고 케스팅용 슬러리의 유기물질은 결합제로 PVB 가소제로는 DBP 용제 로는 에탄올과 톨류엔 그리고 분산제로는 fish oil을 사용하였다. 케스팅하여 얻어진 그린쉬 트를 13$25^{\circ}C$와 135$0^{\circ}C$에서 1시간 소성하여 얻은 쉬트형 PTCR을 온도에 대한 저항 및 복소 임피던스를 측정하고 미세구조를 SEM으로 관찰하여 칩화를 위한 조건들을 검토하였다.

Perfect Tracking Control for Linear Systems with State Constraint

  • Baang, Dane;Choi, Jin-Young;Shim, Hyung-Bo
    • International Journal of Control, Automation, and Systems
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    • v.5 no.2
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    • pp.218-222
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    • 2007
  • This paper presents a new Perfect Tracking Control (PTC) scheme for linear systems with state constraint. The proposed controller increases the number of the steps on-line for perfect tracking to satisfy the given ellipsoid-type state constraint. The unavoidable step delay that we impose is minimized by solving LMI feasibility problems and the possible feedback information loss is avoided. The proposed schemes are easy to develop, theoretically simple and clear, and include the conventional PTC as its special case.

Nonsense-mediated mRNA decay at the crossroads of many cellular pathways

  • Lejeune, Fabrice
    • BMB Reports
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    • v.50 no.4
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    • pp.175-185
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    • 2017
  • Nonsense-mediated mRNA decay (NMD) is a surveillance mechanism ensuring the fast decay of mRNAs harboring a premature termination codon (PTC). As a quality control mechanism, NMD distinguishes PTCs from normal termination codons in order to degrade PTC-carrying mRNAs only. For this, NMD is connected to various other cell processes which regulate or activate it under specific cell conditions or in response to mutations, mis-regulations, stresses, or particular cell programs. These cell processes and their connections with NMD are the focus of this review, which aims both to illustrate the complexity of the NMD mechanism and its regulation and to highlight the cellular consequences of NMD inhibition.

DISTORTION OF FLOW MEASUREMENT BY VARIOUS INLET VELOCITY PROFILE OF ORIFICE FLOWMETER (오리피스 유량계의 입구 속도 분포에 따른 유량 계측 왜곡 특성)

  • Shin, B.S.;Kim, N.S.;Lee, S.K.;Bae, Yong-Beom;Keum, O.H.
    • 한국전산유체공학회:학술대회논문집
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    • 2011.05a
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    • pp.596-600
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    • 2011
  • In this numerical analysis, the distortion of flow measurement by inlet velocity profile of orifice flowmeter was investigated. To validate the numerical method, the convergence was monitored and the grid dependency was also checked. realizable k-e model was selected and y+ was about 50 in this calculation. the results shows that the pressure at the pressure tab near pipe wall was changed by inclined inlet velocity profile and it leads to distorted a measurement values of flow through the orifice plate from -3.8% to 9%. Therefore, the fully developed inlet flow was required for accurate flow measurement by orifice flowmeter. If not, the orifice plate installed at wrong location should be re-installed or additional actions should be taken.

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Synthesis of (2,7-dibromo-9,9-dialkyl-substituted-fluorene)s for Poly(dialkylfluorene)s by Phase Transfer Catalytic Reaction

  • Kwon, Seung-Ho;Kim, Jin-Sung;Park, Ji-Ho;Yoo, Jae-Soo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.724-727
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    • 2002
  • 2,7-dibromo-9, 9-dialkyl-substituted-fluorene derivatives were prepared by the alkylation of 2,7-dibromofluorene with various alkyl groups under two-phase phase transfer catalysis (PTC) conditions, as monomers for synthesizing poly(dialkylfluorene)s. Tetra-nbutylammonium hydrogen sulfate (TBAHS) was used as a phase transfer catalyst to enhance nucleophilic substitution. In addition, NaOH in water (25M) was used as a base to generate anions. Compared to conventional alkylation using butyllithium(BuLi), the reaction using the PTC technique attained high selectivity and substantial conversion of reactants, due to the enhanced reaction rate, while the reaction was carried out under moderate conditions. An approximately 90% yield was obtained from the reaction and the reaction time was remarkably reduced. 2,7-dibromo-9,9-dihexyl-fluorene, 2,7-dibromo-9,9-dioctyl-fluorene, and 2,7-dibromo-9,9-di(2-ethylhexyl)-fluorene were effectively synthesized by phase transfer catalytic reaction.

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The Effects of TiO$_2$Addition on the PTC Properties of BaTiO$_3$ (BaTiO$_3$계의 PTC 특성에 미치는 TiO$_2$첨가량의 영향)

  • 김병수;박준식;박광범;손명성;김털수;이덕출
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1996.11a
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    • pp.44-48
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    • 1996
  • We have investigated the influence of Ti/Ba mole ratio in the characteristics of the modified BaTiO$_3$systems with Ca addition. The specimens were fabricated with variations in Ti/Ba mole ratio between 0.995 and 1.01, and sintered in the temperature range between 13$25^{\circ}C$ and 1375$^{\circ}C$. The room temperature resistivity, PTCR effect and ac complex impedence characteristics were studied. It shows that the room temperature resistivity was increased with the increasing Ti/Ba mole ratio and sintering temperature. It was suggested that this result was mainly attributed to its grain-boundary properties

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A Study on the Generating Stiffener and Nesting Using the Parametric Macro (파라메트릭 매크로를 이용한 부재 생성 및 네스팅에 관한 연구)

  • Han, Chang-Bong;Park, Je-Woong
    • Journal of Ocean Engineering and Technology
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    • v.13 no.2 s.32
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    • pp.176-185
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    • 1999
  • Currently, large size shipyards have performed the generating of piece and the nesting using shipbuilding-oriented CAD program, which requires high skilled operator and costs a lot. So, medium and small size shipyards have pursued other way to obtain the generating and the nesting due to an economic and a technical problems. Therefore, this research is to develop a program for the generating of pieces with parametric macro method and a STRIP program for the nesting of pieces by PC.

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