• 제목/요약/키워드: Phase Transfer Synthesis

검색결과 79건 처리시간 0.027초

Analysis of Optical Transfer Function and Phase Error of the Modified Triangular Interferometer

  • 김수길;염정덕
    • 조명전기설비학회논문지
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    • 제21권1호
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    • pp.10-18
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    • 2007
  • We synthesize and analyze the optical transfer function(OTF) of the modified triangular interferometer(MTI) using two-pupil synthesis method and we present the optimal MTI, which can obtain any bipolar function by combining a wave plate and a linear polarizer. Also, we analyze its potential phase error sources caused by polarization components.

TLS를 이용한 QFT의 이득-위상 루프형성법 (A Gain-Phase Loop Shaping Method of QFT using TLS)

  • 김주식;정수현
    • 전기학회논문지P
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    • 제51권2호
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    • pp.94-98
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    • 2002
  • QFT(Quantitative Feedback Theory) is a very practical design technique that emphasizes the use of feedback for achieving the desired system performance tolerances in despite of plant uncertainty and disturbance. The gain-phase loop shaping procedure of QFT is employed to design controller, until the bounds at desired frequencies are satisfied. This paper presents a transfer function synthesis using TLS(Total Least Squares) and offers a loop shaping method with the suggested technique. An example illustrates a feasibility of the presented algorithm.

Stereoselective Transformation of Phytosphingosine to Safingol

  • Kim, Na-Ri;Lee, Sun-Hee;Namgoong, Sung-Keon
    • Bulletin of the Korean Chemical Society
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    • 제30권3호
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    • pp.695-699
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    • 2009
  • A short and efficient synthesis of (2S,3S)-safingol from commercially available D-ribo-(2S,3S,4R)-phytosphingosine is described. The highlights of the synthesis are a stereoselective one-pot transformation of a diol into an epoxide under phase transfer catalytic conditions and a regioselective epoxide-opening reduction with a hydride reagent.

Long Chain Dicationic Phase Transfer Catalysts in the Condensation Reactions of Aromatic Aldehydes in Water Under Ultrasonic Effect

  • Esen, Ilker;Yolacan, Cigdem;Aydogan, Feray
    • Bulletin of the Korean Chemical Society
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    • 제31권8호
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    • pp.2289-2292
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    • 2010
  • Long chain dicationic ammonium salts were used successfully as phase transfer catalyst in the condensation reactions of aromatic aldehydes in water under ultrasonic irradiation for the first time. The quaternary salt having longer distance between the cation centers was more effective than the mono- and dicationic ones having short chain.

First Total Synthesis of (-)-Antofine by Using Catalytic Phase Transfer Alkylation.

  • Lee, Jae-Kwang;Lee, Tae-Ho;Park, Hyeung-Geun;Kim, Deuk-Joon;Kim, Sang-Hee
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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    • pp.183.3-183.3
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    • 2003
  • Phenanthroindolizidine alkaloid, (-)-antofine has attracted attention because of its extremely potent inhibition of cancer cell growth (Its $IC_50$ values have the low nanomolar range). The frist asymmetric total synthesis of (-)-antofine is described. An important feature of this synthesis is the creation of a stereogenic center by enantioselective alkylation using the phase transfer catalyst (PTC) and ring-closing metathesis (RCM) for pyrrolidine ring construction. This synthesis is efficient to allow the asymmetric preparation of other naturally occurring phenanthroindolizidine and phenanthroquinolizidine alkaloid.

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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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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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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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벡터합성법을 이용한 차량 실내소음의 입력원 영향도 평가 (Evaluation of the Inputs Efficiency for the Interior Noise of the Vehicle using Vector Synthesis Method)

  • 양인형;정재은;오재응
    • 한국소음진동공학회논문집
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    • 제20권6호
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    • pp.562-567
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    • 2010
  • A passenger vehicle has various and complicated transmission paths of sound and vibration. In order to identify the mechanism of transfer path, estimation of excitation force and exact modeling of transfer path are required. In this paper vector synthesis technique is employed to identify the characteristics of road noise and its transmission to vehicle compartment through noise and vibration analysis. Vibration reduction efficiency of each transfer path is evaluated by comparing individual vector components obtained virtual simulation. The degree of effect is used to estimate the contribution of vibration input components to total output. And in this paper presents a new technique based on simulation studies using vector synthesis diagram and design of experiments, by which the effects of magnitude and phase change of input paths can be predicted.