• Title/Summary/Keyword: type of a ring

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Roles of the meta- and the ortho-Cleavage Pathways for the Efficient Utilization of Aromatic Hydrocarbons by Sphingomonas yanoikuyae Bl

  • 송정민;김영민;Gerben J. Zylstra;김응빈
    • Korean Journal of Microbiology
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    • v.38 no.4
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    • pp.245-245
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    • 2002
  • Catabolic pathways for the degradation of various aromatics by Sphingomonas yanoikuyae Bl are intertwined, joining at the level of substituted benzoates, which are further degraded vita ring cleavage reactions. The mutant strain EK497, which was constructed by deleting a large DNA region containing most of the genes for biphenyl, naphthalene, m-xylene, and m-toluate degradation, was unable to grow on all of the aromatics tested except for benzoate as the sole source of carbon and energy.S. yanoikuyae EK497 was found to possess only catechol ortho-ring cleavage activity due to deletion of the genes for the meta-cleavage pathway. Wild-type S. yanoikuyae Bl grown on benzoate has both catechol orthoand meta-cleavage activity. However, m-xylene and m-toluate, which are metabolized through methylbenzoate, and biphenyl, which is metabolized through benzoate, induce only the meta-cleavage pathway, suggesting the presence of a substrate-dependent induction mechanism.

Species Identification and Tree-ring Dating of Wood Elements of Joyangru Pavilion, Chuncheon, Korea (춘천 조양루 목부재의 수종과 연륜연대 분석)

  • Park, Suh-Young;Kim, Sang Kyu;Park, Won-Kyu
    • Journal of the Korea Furniture Society
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    • v.20 no.1
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    • pp.52-60
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    • 2009
  • Joyangru, which is located in Woodo mountain in Chuncheon, Korea, was a gate tower of Monsogak. There are little historical records about Joyangru except of the 20th-century records. To study about Joyangru history, a dendrochronological analysis was conducted. We identified also the species of woods, We took 87 samples of wood elements for the species analysis and 13 samples for the dendrochronological analysis. We found 78 hard pines(Diploxylon), 4 Douglass-fir, 3 exotic hard pines(Pinus ponderosa type) and 1 Shorea sp.(Dipterocarpaceae). In the dendrochronological analysis, 2 floor flames were dated in 1887 (with complete sapwood) and 2 beams in 1884. We concluded that Joyangru was reconstructed just after 1888, most likely in 1890 together with Monsogak.

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Total Synthesis of 7,9-Dideoxydaunomycinone, Aglycone of Antitumor Antibiotic Daunorubicin (Ⅰ) (항암항생제 Daunorubicin의 Aglycone, 7,9-Dideoxydaunomycinone의 합성 (제1보))

  • In Ho Cho;Richard P. Rhee;Young Soy Rho;F. M. Hauser
    • Journal of the Korean Chemical Society
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    • v.30 no.1
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    • pp.109-117
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    • 1986
  • 7,9-Dideoxydaunomycinone (32), a late-stage precursor of the aglycone of antitumor antibiotic daunorubicin(2a) was prepared from 3-methoxybenzoic acid(5). Thus, 3-methoxybenzoic acid was converted to 4-methoxy-3-(phenylsulfonyl)-1(3H)-isobenzofuranone(11), which furnished trimethoxynaphthoate 16 upon ring annelation developed by Hauser and Rhee. The trimethoxynaphthoate 16 upon ring annelation developed by Hauser and Rbee. The trimethoxynaphtboate 16 was then transformed into phenylsulfonylnaphthofuranone 22, which was used to make anthracenoate 24 via Michael type reaction with 7-(ethylenedioxy)-2-octenoate(23). Conversion of anthracenoate 24 to tetracyclic product 28, followed by subsequent deprotection of the methyl groups in ring-B and C furnished 7, 9-Dideoxydaunomycinone(32).

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The Vibration Characteristic Improvement by Mode Variation of Ring Type Ultrasonic Motor (리형 초음파모터의 모드가변에 따른 진동특성 개선)

  • 윤신용;김수석
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.18 no.2
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    • pp.115-124
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    • 2004
  • This paper suggested the vibration characteristic improvement by variation mode of ring type ultrasonic motor. Design for the piezoelectric ceramic and elastic body of stator were calculated by the finite element method(FEM) that consider the resonance frequency, vibration mode and coupling efficiency etc. Through the result of vibration analysis from 6 order mode to 8 mode, the 7 order mode was gained very an excellent results that it was the coupling efficient, minimum power loss and bending vibration value. Here over 7 order mode, was acquired that an output current for input voltage was very a large increased results. The result of vibration calculation, from thickness 0.5[mm] to 2[mm], know the fact that the vibration displacement at 0.5[mm] is an high value too. From such analysis result, this paper was manufactured the ultrasonic motor of outer diameter 50[mm], inter 22[mm] having the about 43.86[KHz] resonance frequency. We have gated that a simulation result is 42.2[KHz] and an experiment result is 43.86[KHz]. Then, a propriety of this paper was established the result almost similar to though comparison, investigation of simulation and experiment result.

Design of the Microwave Oscillator with the C type DGS Resonator (C형태의 DGS 공진기를 이용한 초고주파 발진기 설계)

  • Kim, Gi-Rae
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.8 no.4
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    • pp.243-248
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    • 2015
  • Since phase noise is one of the most important parameters in the design of microwave oscillators, several methods have been proposed to reduce the phase noise. These methods have focused on improving the quality factor of resonators, which result in low phase noise oscillators. Dielectric resonators have been widely used for low phase noise in microwave oscillators due to their high quality factor. However this cannot be used in MMIC oscillators because they have a 3D structure. In this paper, to overcome this problem a novel resonator using open ring type DGS is proposed for improvement of phase noise characteristics that is weak point of oscillator using planar type microstrip line resonator, and oscillator for 5.8GHz band is designed using proposed DGS resonator. The open ring type DGS resonator is composed of DGS cell etched on ground plane under $50{\Omega}$ microstrip line. At the fundamental frequency of 5.8GHz, 6.1dBm output power and -82.7 dBc@100kHz phase noise have been measured for oscillator with ring type DGS resonator. The phase noise characteristics of oscillator is improved about 96.5dB compared to one using the general ${\lambda}/4$ microstrip resonator.

Force factor of the stator used for ring type ultrasonic motor (링형 초음파 모터 고정자의 Force Factor)

  • Jeong, S.H.;Lee, J.S.;Yuk, H.S.;Chae, H.I.;Lim, K.J.;Bae, H.D.
    • Proceedings of the KIEE Conference
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    • 1993.07b
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    • pp.1125-1129
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    • 1993
  • A piezoelectric ring type plate, which vibrates in flexural vibration mode, is used for the stator of ultrasonic motor. To design the stator adequately, the force factor of the stator should be estimated in advance. The theoretically calculated force factors for the flexural vibration mode are compared with the measured ones to obtain good agreement. In order to study how to control the force factor, the relation between the shape of the stator and force factor is also considered.

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