• Title/Summary/Keyword: 삼중해

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Studies on the Photoreactions of Coumarins and Furocoumarins (쿠마린과 푸로쿠마린의 광화학반응에 관한 연구)

  • Shim Sang Chul;Im Kyung Ran
    • Journal of the Korean Chemical Society
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    • v.20 no.3
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    • pp.236-239
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    • 1976
  • The mechanism of skin-sensitizing photoreactions of coumarins and furocoumarins are studied by spectroscopic, triplet quenching, and fluorescence techniques. The excited singlet mechanism is suggested for xanthotoxin-thymine/or DNA photoreactions from the results of triplet quenching studies utilizing ${\beta}$-carotene as a quencher.

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The Color and Spectroscopic Properties of Polyacetylene Derivatives(Ⅵ): Synthesis and Properties of Poly (2-ethynyl-N-methylpyridinium iodide ) and Poly (2- ethyny1-N-methylpyridinium tetraphenylborate)

  • 이원철;제갈영순;진성호;임용진
    • Proceedings of the Korean Society of Dyers and Finishers Conference
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    • 2003.04a
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    • pp.197-202
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    • 2003
  • 아세틸렌 화합물의 삼중결합은 2개의 $\pi$-결합을 가지고 있는 전자풍부 화학종으로서 다양한 촉매 system에 의해서 비교적 쉽게 부가중합반응이 진행되며 이를 통하여 공액구조 고분자를 쉽게 제조할 수 있다. 가장 간단한 삼중결합 화합물인 아세틸렌은 다양한 촉매 system에 의해서 쉽게 부가중합반응이 진행되어 분말상의 폴리아세틸렌이 합성되었으며 1974년 일본의 Shirakawa 등은 Ziegler-Natta 촉매의 일종인 Ti(OC$_4$H$_{9}$)$_4$-Al(C$_2$H$_{5}$)$_3$(Al/Ti = 3-4) 촉매 system을 사용하여 실험한 결과 은빛의 필름형 폴리아세틸렌의 합성에 성공하였다. (중략)

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A Study on the Flow Characteristics of the Triple Jets Using Particle Image Velocimetry (PIV를 이용한 삼중 제트의 유동 특성에 관한 연구)

  • Lee Myung Jae;Yoon Soon Hyun;Kim Dong Keon;Kim Moon Kyung
    • 한국가시화정보학회:학술대회논문집
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    • 2005.12a
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    • pp.28-35
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    • 2005
  • Experiments were conducted to show the characteristics of the flow on triple parallel plane impinging jets. Measurements of mean velocity components and turbulent intensities were carried out with a particle image velocimetry(PIV) to investigate the flow field generated by the air issued from three identical plane parallel nozzles and mixed with the ambient air. The measurements range of these experiments were Reynolds number of 5000 and 1000 based on the nozzle width and the case of nozzle-to-plate distances were two times, six times and ten times the width of the nozzle. Results show that recirculation region of Re=5000 is the stronger than that of Re=1000. Therefore, velocity loss of centerline for Re=5000 that shows strongly recirculation region takes effect greatly.

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Computer-aided Design and Fabrication of Bio-mimetic Scaffold for Tissue Engineering Using the Triply Periodic Minimal Surface (삼중 주기적 최소곡면을 이용한 조직공학을 위한 생체모사 스캐폴드의 컴퓨터응용 설계 및 제작)

  • Yoo, Dong-Jin
    • Journal of the Korean Society for Precision Engineering
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    • v.28 no.7
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    • pp.834-850
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    • 2011
  • In this paper, a novel tissue engineering scaffold design method based on triply periodic minimal surface (TPMS) is proposed. After generating the hexahedral elements for a 3D anatomical shape using the distance field algorithm, the unit cell libraries composed of triply periodic minimal surfaces are mapped into the subdivided hexahedral elements using the shape function widely used in the finite element method. In addition, a heterogeneous implicit solid representation method is introduced to design a 3D (Three-dimensional) bio-mimetic scaffold for tissue engineering from a sequence of computed tomography (CT) medical image data. CT image of a human spine bone is used as the case study for designing a 3D bio-mimetic scaffold model from CT image data.

남해구 자원관리형 자망ㆍ통발 어구어법 기술개발에 관한 연구 -어획물의 종조성과 체장분포-

  • 이주희;권병국;이춘우;조영복;유제범;김성훈;김부영
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2003.10a
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    • pp.63-66
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    • 2003
  • 남획에 의한 어자원 감소와 오염으로 인한 해양 환경의 변화, 그리고 주변국과의 어업협정 체결 및 수입 개방 조치 등에 의한 어업정책의 변경으로 어업인의 소득이 심각한 타격을 입게 되면서, 어획 성능이 우수하고 조업 방식이 간편하며 소요 경비가 절감되는 어구어법으로의 전환이 빠르게 진행되고 있는 실정이다. 삼중자망은 홑자망, 통발에 비해 조업방법이 간단하고 특별한 어로설비를 필요로 하지 않으며 우수한 어획성능을 가지고 있어 어업인들이 선호하고 있으나 심각한 자원 남획을 유발하는 어구이기 때문에, 삼중자망의 불법사용에 대한 규제와 단속을 지속적으로 실시하고 있다. (중략)

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Fundamental Study of Unit Proton Exchange Membrane Electrolysis for Realtime Detection of Tritium (실시간 삼중수소 검출을 위한 단위 양성자 교환 막 전기분해 기초연구)

  • CHAE, JONGMIN;YU, SANGSEOK
    • Transactions of the Korean hydrogen and new energy society
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    • v.29 no.2
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    • pp.226-234
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    • 2018
  • Even though the nuclear power plants has many advantages, safety issues of nuclear power plants are crucial factors of reliable operation. A tritium detector is a useful sensor to analyze amount of exposed radiation from the nuclear power plants. Currently, concentration of underwater tritium is measured precisely but it takes very long time. Since electrolysis is extracted hydrogen from the coolant of nuclear power plant, it can motivate to develop new type of real-time sensor. In this study, Proton Exchange Membrane (PEM) electrolyzer is studied for candidate as preprocessor of real-time tritium detector. Characteristics of the unit PEM electrolyzer were experimentally investigated. A simulation model is developed to understand physical behavior of unit PEM electrolyzer under dynamic operation.

Macroscopic Breakup Characteristics of Water Gel Simulants with Triplet Impinging Spray Jet (젤 모사 추진제 삼중 충돌 분사 제트의 거시적 분열 특성 연구)

  • Hwang, Tae-Jin;Lee, In-Chul;Koo, Ja-Ye
    • Journal of ILASS-Korea
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    • v.15 no.3
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    • pp.109-114
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    • 2010
  • The implementation of gelled propellants systems offers high performance, energy management of liquid propulsion, storability, and high density impulse of solid propulsion. The present study focused on the macroscopic spray characteristics of liquid sheets formed by triplet impinging jets of non-Newtonian liquids which are mixed by Carbopol 941 0.5%wt. The results are compared to experiments conducted on spray images which formed by triplet impinging jets concerning with airassist effect at center orifice. When gel propellants are injected by doublet impinging jets at low pressure and high pressure, closed rim pattern shape appeared by polymeric effect from molecular force and showed inactive atomization characteristics, because of extensional viscosity related by restriction of atomization process and breakup time delay of turbulence transition. As increasing mass flow rate of the air(increasing GAR), spray breakup level is also increased.