• 제목/요약/키워드: synthesize

검색결과 1,516건 처리시간 0.026초

Barium titanate doping on superconducting perovskite YBCO

  • Soh, Deawha;Korobova, N.;Li, Ying-Mei;Cho, Yong-Joon;Kim, Tae-Wan
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2000년도 추계학술대회논문집
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    • pp.120-123
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    • 2000
  • This paper reports a newly developed sol-gel process to synthesize dense YBCO thick films with BaTiO$_3$additives using electrophoretic deposition and metal alkoxide sol/particle suspension, which we successfully produce dense $YBCO+BaTiO_3$ ceramics at a rather low temperature, compared with the sintering temperature used in conventional methods. The thick films of HTS were prepared by electrophoretic deposition, using pre-sintered powder with barium titanate addition in the form of $BaTi(OR)_6$ solution in suspension for electrophoresis. The conditions for applied voltage and deposition times for electrophoretic deposition of HTS thick films were studied in detail.

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A Level Dependent Source Concoction Multilevel Inverter Topology with a Reduced Number of Power Switches

  • Edwin Jose, S.;Titus, S.
    • Journal of Power Electronics
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    • 제16권4호
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    • pp.1316-1323
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    • 2016
  • Multilevel inverters (MLIs) have been preferred over conventional two-level inverters due to their inherent properties such as reduced harmonic distortion, lower electromagnetic interference, minimal common mode voltage, ability to synthesize medium/high voltage from low voltage sources, etc. On the other hand, they suffer from an increased number of switching devices, complex gate pulse generation, etc. This paper develops an ingenious symmetrical MLI topology, which consumes lesser component count. The proposed level dependent sources concoction multilevel inverter (LDSCMLI) is basically a multilevel dc link MLI (MLDCMLI), which first synthesizes a stepped dc link voltage using a sources concoction module and then realizes the ac waveform through a conventional H-bridge. Seven level and eleven level versions of the proposed topology are simulated in MATLAB r2010b and prototypes are constructed to validate the performance. The proposed topology requires lesser components compared to recent component reduced MLI topologies and the classical topologies. In addition, it requires fewer carrier signals and gate driver circuits.

Carbon Nanotube Synthesis using Magnetic Null Discharge Plasma Production Technology

  • Sung, Youl-Moon
    • Journal of Electrical Engineering and Technology
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    • 제2권4호
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    • pp.532-536
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    • 2007
  • Carbon nanotube (CNT) properties, produced using a magnetic null discharge (MND) plasma production technology, were investigated. We firstly deposited the Fe layer 200 nm in thickness on Si substrate by the magnetic null discharge sputter method at the substrate temperature of $300도C$, and then prepared CNTs on the catalyst layer by using the magnetic null discharge (MND) based CVD method. CNTs were deposited in a gas mixture of CH4 and N2 at a total pressure of 1 Torr by the MND-CVD method. The substrate temperature and the RF power were $650^{\circ}C$ and 600W, respectively. The characterization data indicated that the proposed source could synthesize CNTs even under relatively severe conditions for the magnetic null discharge formation.

아르누보의 선형적 의미와 특성에 관한 연구 (A Study on Linear meanings and Characteristics of Art Nouveau)

  • 김성혜
    • 한국실내디자인학회논문집
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    • 제19호
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    • pp.98-104
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    • 1999
  • The literal Meaning of Art Nouveau is 'New Art'. It means that Art Nouveau was conceived momentous sense of transition in the close of 19C and found the way to overcome that situatiov. So, This Study aims to discover the Meaning and Characteristic of Art Nouveau through it's Linear form. Through this study, linear form of Art Nouveau served not merely to decorate building, but to liberate space. With linear forms, Art Nouveau artists synthesize all exterior and interior elements - from doors and windows to carpets and furnishings - by one's emotional rhythm and occasionally change the feel of space that adorned with another style. First, of all, linear form is a method for 'Art for Art sake', and the possibility of linear form does not disappear.

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Photoaddtion Reactions of ο-Benzoquinones to Some Olefins and Alkynes

  • Kim, Sung-Sik
    • Journal of Photoscience
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    • 제5권4호
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    • pp.143-148
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    • 1998
  • Photoaddition reactions of ο-benzoquinones to some organic molecules were ivestigated to yield three types of photoadducts. Irradiation (350nm UV light) of a dichloromethane solution of tetrahal-1, 2- benzoquinones and 1, 4-diphenylbutadiene yielded 1, 3-dienes, which was found to be used to synthesize 1-phenylphenanthrenes. The 1, 3-dienes were also produced, when irradiated tetrahalo--1, 2-benzoquinones and 1,4-dipenylbut-1-en-3-yne in the similar conditions, which was applied to get 9-phenylphenanthrenes. An enolic compound come from the tautomerization of dibenzoylmethane was found to add to ο-benzoquinones to give, 1, 4-dioxenes and 1, 5-diketones as the major products. Although depenylbutadiyne did not add to ο-benzoquinones, diphenylacetylene added to ο-benzoquinones to give $\rho$-quinomethanes as well as two isomeric $\rho$-quinomethanes. One-way photoisomerism was observed for two isomeric $\rho$-quinomethanes.

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Conversion of Citron (Citrus junos) Peel Oil by Enterobacter agglomerans

  • PARK , YEON-JIN;KIM, IN-CHEOL;BAEK, HYUNG-HEE;BANG, OK-KYUN;CHANG, HAE-CHOON
    • Journal of Microbiology and Biotechnology
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    • 제14권6호
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    • pp.1275-1279
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    • 2004
  • Citron peel oil was extracted from citron (Citrus funas) fruit by steam distillation, and was used as starting material for microbial conversion to synthesize attractive flavor compounds by using Enterobacter agglomerans 6L. E. agglomerans was isolated from citron peel and was able to metabolize the citron peel oil and grew well ($A_{600}:\;3.0$) on the citron peel oil as the sole carbon source. Multiple terpene metabolites were produced by E. agglomerans 6L on M9 salt media with citron oil vapor. The identified bioconversion products from the citron peel oil included trans-2-decenal, octanol, $\delta$­valerolactone, $\gamma$-valerolactone, cryptone, hydroxycitronellol, cuminol, and $\gamma$-dodecalactone.

Cloning and Expression of B. Aphaericus insecticidal toxin gene in E. coli

  • Lim, Pyong-Ok;Lee, Hong-Sup;Lee, Hyung-Hoan
    • 한국미생물생명공학회:학술대회논문집
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    • 한국미생물생명공학회 1986년도 추계학술대회
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    • pp.515.2-515
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    • 1986
  • B. sphaericus 1593 K-5 synthesize a potent entomicidal toxin against mosquito larvae. B. sphaericus EcoRl DNA fragment carrying the biocidal activity was clonied and expression in E. coli JM83. For the construction of a recombinant plasmid bearing the toxin activity the DNA of B. sphaericus was partially digested by the EcoRl. The EcoRl DNA fragments were ligated to plasmid pUC 8-EcoR1 site. The transformants were selected on LB plates containing X-gall and ampicilline. The transformants were bioassayed against mosquito larvae of which two clones showed biocidal activity. The two clones were redigested with Eco R1 and analyzed by 0.7% agarose gel electrophorsis.

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Biological Synthesis of 7-O-Methyl Apigenin from Naringenin Using Escherichia coli Expressing Two Genes

  • Jeon, Young-Min;Kim, Bong-Gyu;Ahn, Joong-Hoon
    • Journal of Microbiology and Biotechnology
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    • 제19권5호
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    • pp.491-494
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    • 2009
  • Within the secondary metabolite class of flavonoids, which consist of more than 10,000 known structures, flavones define one of the largest subgroups. The diverse function of flavones in plants as well as their various roles in the interaction with other organisms offers many potential applications including in human nutrition and pharmacology. We used two genes, flavone synthase (PFNS-l) that converts naringenin into apigenin and flavone 7-O-methyltransferase (POMT-7) that converts apigenin into 7-O-methyl apigenin, to synthesize 7-O-methyl apigenenin from naringenin. The PFNS-l gene was subcloned into the E. coli expression vector pGEX and POMT-7 was subcloned into the pRSF vector. Since both constructs contain different replication origins and selection markers, they were cotransformed into E. coli. Using E. coli transformants harboring both PFNS-l and POMT-7, naringenin could be converted into 7-O-methyl apigenin, genkwanin.

논의 수문특성을 고려한 소유역의 유출곡선 합성 (Runoff Hydrograph Synthesis from Small Watersheds Considering Hydrological Characteristics of Irrigated Rice Paddies)

  • 김철겸;박승우;임상준
    • 한국농공학회지
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    • 제42권6호
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    • pp.56-62
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    • 2000
  • The NRCS curve number (CN) method has been widely adopted in practice to synthesize runoff hydrographs from small watersheds with complex land use. It may not be valid to apply this model for irrigated paddies, since hydrological characteristics of irrigated rice paddies are not sufficiently considered in CN method. This paper attempts to extend the capability of the well-known SCS TR-20 model to local conditions by formulating a submodel for the runoff-processes in paddies. The modified model was tested with field data from the Baran watershed. The results were in good agreement with field data. It was also applicable to simulate runoff changes resulting from land use changes within the watershed.

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Rayon-like 폴리에스터의 합성(合成) (Syntheses of Rayon-like Polyester)

  • 안영무;박영기
    • 패션비즈니스
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    • 제11권5호
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    • pp.155-164
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    • 2007
  • Viscose rayon has advantages such as vivid luster, good dyeability, low static electricity, good absorbance and good spinnability but also has flaws such as easy crease and decrease of physical properties when it gets wetting, and it requires dry cleaning. Therefore in order to synthesize the polymer to solve the problems of rayon while keeping the advantages of it, this study made the high specific gravity polyester for ultra drape property and high contraction polyester for rayon-like fiber having volume, soft and warm sense. The polyester with high specific gravity, 1.47 was made by adding 7 wt% of $BaSO_4$ as additive. High contraction polyester was made by copolymerization by using IPA 5 mole% to increase the amorphous region as comonomer and also using Newpol BPE-20(NPE) 1.5 wt% not to decrease the properties.