• Title/Summary/Keyword: Cascade reaction

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Synthesis of Dienamides via the Reaction of Nitrile with Allylindium Reagents and Intramolecular Acyl Group Quenching Cascade

  • Kim, Sung-Hwan;Kim, Yu-Mi;Kim, Jae-Nyoung
    • Bulletin of the Korean Chemical Society
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    • v.31 no.8
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    • pp.2351-2356
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    • 2010
  • Various dienamide derivatives were synthesized in reasonable yields from benzonitriles having an amide moiety at the ortho-position, via the sequential (i) In-mediated allylation of nitrile moiety to form an imine intermediate, (ii) intramolecular quenching of an acyl group by the imine intermediate, and (iii) a proton transfer to dienamide.

Production of enantiopure epoxides by yeast epoxide hydrolase using a two-phase membrane bioreactor (한국생물공학회 정기총회 및 연구논문발표회 발표논문)

  • Choe, Won-Jae;Choe, Cha-Yong
    • 한국생물공학회:학술대회논문집
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    • 2000.04a
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    • pp.145-148
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    • 2000
  • Large-scale resolution of epoxides by the yeast Rhodotorula glutinis was demonstrated in an aqueous/organic two-phase cascade membrane bioreactor. Due to the chemical instability and low solubility of epoxides in aqueous phases, an organic solvent was introduced into the reaction mixture in order to enhance resolution of epoxide. A cascade hollow-fiber membrane bioreactor was used (i) to minimize the toxicity of organic solvents towards the epoxide hydrolase of Rhodotorula glutinis, and (ii) to remove inhibitory amounts of formed diol from the yeast cell containing aqueous phase. Dodecane was selected as a suitable solvent and 1,2-epoxyhexane as a model substrate. By use of this membrane bioreactor, highly concentrated (0.9 M in dodecane) enantiopure (>98% ee) (S)-1,2-epoxyhexane (6.5 g, 30% yield) was obtained from its racemic mixture.

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Automatic Indexing Algorithm of Golf Video Using Audio Information (오디오 정보를 이용한 골프 동영상 자동 색인 알고리즘)

  • Kim, Hyoung-Gook
    • The Journal of the Acoustical Society of Korea
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    • v.28 no.5
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    • pp.441-446
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    • 2009
  • This paper proposes an automatic indexing algorithm of golf video using audio information. In the proposed algorithm, the input audio stream is demultiplexed into the stream of video and audio. By means of Adaboost-cascade classifier, the continuous audio stream is classified into announcer's speech segment recorded in studio, music segment accompanied with players' names on TV screen, reaction segment of audience according to the play, reporter's speech segment with field background, filed noise segment like wind or waves. And golf swing sound including drive shot, iron shot, and putting shot is detected by the method of impulse onset detection and modulation spectrum verification. The detected swing and applause are used effectively to index action or highlight unit. Compared with video based semantic analysis, main advantage of the proposed system is its small computation requirement so that it facilitates to apply the technology to embedded consumer electronic devices for fast browsing.

Modeling and controller design for a continuous copolymerization reactor (연속식 공중합 반응기의 모델링 및 제어기 설계)

  • 황우현;이현구
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.788-791
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    • 1996
  • A mathematical model is developed for thermal solution copolymerization of styrene and acrylonitrile in a continuous stirred tank reactor(CSTR). Computational studies are carried out with the continuous copolymerization system model developed in this work to give the monomer conversion, copolymer composition and the average molecular weights of the copolymer. By performing the dynamic analysis of the reaction system, the polymer properties against the changes in the operating conditions are determined quantitatively. The cascade PID and fuzzy controller show satisfactory performances for both set point tracking and disturbance rejection. Especially, the fuzzy controller is superior to the PID controller.

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Importance of Sperm Capacitation, Removal of Cumulus Matrix, Acrosome Reaction, and Sperm-egg Fusion in the Process of In Vitro Fertilization

  • Kim, Ki-Sun;Hwang, Kyung-A;Kim, Hyoung-Chin;Nam, Ki-Hoan;Choi, Kyung-Chul
    • Journal of Embryo Transfer
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    • v.26 no.4
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    • pp.287-296
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    • 2011
  • Mammalian fertilization is a complex cascade process consisting of sperm migration through the female reproductive tract, physiological changes to sperm such as sperm capacitation and acrosome reaction, and sperm-egg interaction in the oviduct in vivo. On the other hand, in vitro fertilization (IVF) is a process by which egg cells are fertilized by sperm outside the body: in vitro. IVF has been used for a variety of purposes in reproductive biotechnology for human and animals. The discovery of sperm capacitation in 1951 promoted the development of IVF technology. In the initial stage of IVF, sperm capacitation in preincubation medium was shown to be essential to fuse with eggs. Besides, sperms should detour some of the in vivo regulations for IVF. This review introduces a general mammalian fertilization process, including sperm capacitation, removal of cumulus matrix, acrosome reaction, and sperm-egg fusion and focuses on the roles of key biochemical molecules, signal mechanisms, and genes involved during IVF and novel results of sperm-oocyte interaction elucidated in various gene-knockout mice models.