• Title/Summary/Keyword: Dab1

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Preparation of Cation Exchange Membrane using Polybenzimidazole and Its Characteristic (폴리벤지미다졸(PBI)을 이용한 양이온교환막의 제조 및 특성)

  • Kim, Joeng-Geun;Lee, Sang-Ho;Ryu, Cheol-Hwi;Hwang, Gab-Jin
    • Membrane Journal
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    • v.22 no.4
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    • pp.265-271
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    • 2012
  • Polybenzimidazole (PBI) was prepared by condensation polymerization using diaminobenzidine (DAB) and isophtalic acid (IPAc). The cation exchange membrane was prepared by introduce the ion exchange group in the PBI polymer. It was confirmed from FT-IR analysis that the prepared PBI powder had same peak compared with commercial PBI power. The ionic conductivity of PBI film was $0.1{\sim}0.9{\times}10^{-2}$ S/cm. The ionic conductivity of prepared SPBI cation exchange membrane showed $3.7{\sim}4.7{\times}10^{-2}$ S/cm and had higher than Nafion117 ($2.0{\times}10^{-2}$ S/cm).

Design and Implementation of a Bidirectional Power Supply Charger Using Super Capacitors and Solar Panel for Robot Cleaner Applications (슈퍼 커패시터 및 태양전지를 이용한 로봇청소기용 양방향 충전시스템 설계)

  • Zheng, Tao;Piao, Sheng-Xu;Kwon, Dae-Hwan;Qiu, Wei-Jing;Kim, Hee-Je
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.1
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    • pp.97-102
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    • 2016
  • In this paper, a bidirectional power supply charger is proposed. This system used a solar cell panel to generate electricity and used super capacitors to store these energies, which can be used for the robot cleaner or some other electronic products. This system include a phase-shift controlled bidirectional dual active bridge (DAB) converter, solar panel super capacitors and DSP controller. In the daytime it can charge to the super capacitors to store the energy generated by the solar cell panel and in the night it will release the energy stored in the super capacitors to loads. A prototype of the proposed bidirectional power supply charger system was designed which can achieve 18V to 30V input, 10V/20W output to super capacitors and 9V/6.5W output when it acts as a charger for the robot cleaner. The system is verified to be sTable and reliable by both the simulation and experimental results.

Synthesis and Characterization of Fluorinated Polybenzimidazole Proton Exchange Membranes for Fuel Cell (연료전지용 불소화 폴리벤즈이미다졸 양성자 교환 멤브레인 합성 및 특성평가)

  • KIM, AE RHAN
    • Journal of Hydrogen and New Energy
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    • v.28 no.1
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    • pp.24-29
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    • 2017
  • A fluorinated polybenzimidazole (FPBI) was synthesized from 3,3-diaminobenzidine (DAB) of tetraamine, 2,2-bis(4-carboxyphenyl)hexafluoropropane of aromatic biscarboxylic acid, and 4,4-sulfonyldibenzoic acid of aromatic biscarboxylic acid in polyphosphoric acid (PPA). A FPBI was easily cast and made into clear films. The structure of condensation polymers and corresponding membranes were analyzed using GPC (gel permeation chromatography), $^1H$-NMR ($^1H$ nuclear magnetic resonance) and FT-IR (fourier transform infrared). TGA (thermogravimetric analysis) analysis showed that the prepared membranes were thermally stable, so that elevated temperature fuel cell operation would be possible. The proton conductivity of the FPBI membranes increased with increasing temperatures in the polymer. A FPBI membrane has a maximum ion conductivity of 45 mS/cm at $90^{\circ}C$ and 100% relative humidity.

Double-Enhancement Strategy: A Practical Approach to a Femto-Molar Level Detection of Prostate Specific $Antigen-{\alpha}_1-Antichymotrypsin$ (PSA/ACT Complex) for SPR Immunosensing

  • Cao, Cuong;Sim, Sang-Jun
    • Journal of Microbiology and Biotechnology
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    • v.17 no.6
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    • pp.1031-1035
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    • 2007
  • Prostate specific $antigen-{\alpha}_1-antichymotrypsin$ was detected by a double-enhancement strategy involving the exploitation of both colloidal gold nanoparticles (AuNPs) and precipitation of an insoluble product formed by HRP-biocatalyzed oxidation. The AuNPs were synthesized and conjugated with horse-radish peroxidase-PSA polyclonal antibody by physisorption. Using the protein-colloid for SPR-based detection of the PSPJACT complex showed their enhancement as being consistent with other previous studies with regard to AuNPs enhancement, while the enzyme precipitation using DAB substrate was applied for the first time and greatly amplified the signal. The limit of detection was found at as low as 0.027 ng/ml of the PSA/ACT complex (or 300 fM), which is much higher than that of previous reports. This study indicates another way to enhance SPR measurement, and it is generally applicable to other SPR-based immunoassays.

Shear Bond Strength of a 3-in-1 Flowable Composite Resin to Primary Teeth (유치에 대한 3-in-1 유동성 복합레진의 전단결합강도)

  • Lee, Hyeongjik;Shin, Jonghyun;Kim, Jiyeon;Jeong, Taesung;Kim, Shin
    • Journal of the korean academy of Pediatric Dentistry
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    • v.45 no.4
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    • pp.436-444
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    • 2018
  • The purpose of this study was to compare the shear bond strengths of 3-in-1 flowable composite to the enamel and dentin of primary teeth to previous adhesive systems. 110 primary incisors were prepared and divided into two groups: Dentin group included 5 groups: 1) Scotch bond Multi-purpose plus(DSM), 2) Single-bond 2(DSB), 3) Clearfil SE bond(DSE), 4) All bond universal(DAB), 5) Constic(DC), and Enamel group included 6 groups: 1) Scotch bond Multi-purpose plus(ESM), 2) Single bond 2(ESB), 3) Clearfil SE bond(ESE), 4) All bond universal(EAB), 5) Constic(EC), 6) Constic with additional etching(ECE). A cylinder of composite was bonded to the prepared surface, and the shear bond strength was measured. In the dentin groups, group DC had significantly lower shear bond strength than group DSE. No significant difference was found between group DC, group DSM, group DSB and group DAB. In the enamel groups, there was no significant difference between group EC, group ESE, and group EAB. This material showed lowest shear bond strength among all tested materials in both enamel and dentin groups, showing insignificant difference with some adhesive systems. Therefore, 3-in-1 flowable composite can be used for primary teeth restoration but further studies are needed.

Asymmetric Total Synthesis of the Glycosidase Inhibitor, 1,4-dideoxy-l,4-imino-D-arabinitol(DAB1)

  • Kim, In-Su;Hoon, Jung-Young
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2003.11a
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    • pp.115-115
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    • 2003
  • Naturally occurring sugar mimics with a nitrogen in the ring are classified into five structural classes: polyhydroxylated pyrrolidines, piperidines, indolizidines. pyrrolizidine, and nortropanes. Glycosidase are involved in a wide range of important biological processes, such as intestinal digestion, post-translational processing of glycoproteins and the lysosomal catabolism of glycoconjugate. The realization that alkaloidal sugar mimics might have enormous therapeutic potential in many diseases such as viral infection, cancer and diabetes has led to increasing interest and demand for these compounds. Most of these effects can be shown to result from the direct or indrect inhibition of glycosidases.

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Electron Microscopic Studies on Microbody of Panax ginseng (인삼(人蔘)의 Microbody에 관(關)한 전자현미경적(電子顯微鏡的) 연구(硏究))

  • Kim, Woop-Kap;Lee, Bong-Hee;Oh, Chong-Yon
    • Applied Microscopy
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    • v.2 no.1
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    • pp.33-37
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    • 1972
  • The distribution, ultrastructure, and cytochemical properties of microbodies (peroxisomes) from the main roots and mature leaves of Panax ginseng were studied by electron microscopy included the activity of catalase in 3, 3'-diaminobenzidine (DAB) medium at pH 9, using glutaraldehyde-fixed tissues. The microbodies, which are about $0.5{\sim}1.5{\mu}$ diameter, were described from mesophyll cells of mature leaves and storage cells and cambial cells of main roots. The microbodies of the ginseng include the coreless, homogeneous matrix, in which catalase activities are present.

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Performance Analysis of PAR Reduction Method using Combined Method in OFDM (OFDM에서 혼합방법을 이용한 PAR 경감법의 성능 해석)

  • 변건식;장은영;김성곤;전제훈
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.1
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    • pp.42-49
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    • 2003
  • OFDM should be used for the fourth generation communication for high speed communication. Because of high spectral efficiency and high tolerance to fading channel, OFDM is applied to many high speed wire and wireless communication such as DAB (Digital Audio Broadcast), DVB(Digital Video Broadcast), IMT 2000 etc. Inter-modulation, however, is derived from PAR(Peak to Average Power Ratio) of OFDM signals. The paper describes PTS(Partial Transmit Sequence) and SLM(Select Mapping) of an existing methods which can reduce PAR. And then this papers proposed the new method that is called "Combine method". The method proposed in this paper is to combine PTS and SLM. As a result of the simulation, Combine PAR method is better than the existing methods.