• Title/Summary/Keyword: prepare

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Electric Field Dispersion Techniques of Epoxy-Layered Silicate Nanocomposites (에폭시-층상실리케이트 나노콤포지트의 전기장 분산기술)

  • Lee, Chang-Hoon;Lee, Jae-Yeong;Park, Jae-Jun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.03b
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    • pp.30-30
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    • 2010
  • In order to prepare a epoxy/multilayered silicate nanocomposite, various mixing processes were tried and it was found that the silicate could not be fully exfoliated in the epoxy matrix through various mechanical mixing process. In this study, a new AC electric application method was developed to prepare epoxy/multilayered silicate nanocomposite. The exfoliation of the silicate was confirmed by XRD (X-Ray Diffraction) and TEM observation.

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Large-Scale Assembly of Aligned Graphene Nanoribbons with Sub 30-nm Width

  • Kim, Taekyeong
    • Journal of the Korean Chemical Society
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    • v.58 no.6
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    • pp.524-527
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    • 2014
  • We report a simple yet efficient method to assemble large-scale aligned graphene nanoribbons (GNRs) with a width as small as 30 nm. The $V_2O_5$ nanowires (NWs) were aligned on a graphene surface via spraying a solution of the $V_2O_5$ NWs, and the graphene was selectively etched by the reactive ion etching method using the $V_2O_5$ NWs as a shadow mask. This process allowed us to prepare large scale patterns of the aligned GNRs on a $SiO_2$ substrate. The orientation of the aligned and randomly oriented GNRs was compared by the atomic force microscope (AFM) images. We achieved the highly aligned GNRs along the flow direction of the $V_2O_5$ NWs solution. Furthermore, we successfully fabricated a field effect-transistor with the aligned GNRs and measured its electrical properties. Since our method enable to prepare the aligned GNRs over a large area, it should open up new way for the various applications.

Preparation of Smart Probiotic Solid Lipid Nanoparticles (SLN) for Target Controlled Nanofood

  • Kim, Dong-Myung
    • Journal of Dairy Science and Biotechnology
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    • v.25 no.2
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    • pp.5-10
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    • 2007
  • Ultrasonication was employed to prepare solid lipid nanoparticles (SLN) for smart probiotic nanoparticles as a nanofood. The model probiotic material, lactocin from Lactobacillus plantarum (CBT-LP2), was incorporated into SLN. The CBT-LP2 loaded SLN (CBT-LP2-SLN) were spherical in the photograph of scanning electron microscope (SEM). The particle size measured by laser diffraction (LD) was found to be $97.3{\pm}8.2nm$. Zeta potential analyzer suggested the zeta potential of LP-SLN was $-29.36{\pm}3.68$ mV in distilled water. The entrapment efficiency (EE%) was determined with the sephadex gel chromatogram and high-performance liquid chromatogram (HPLC), and up to 90.59% of nanofood was incorporated. Stability evaluation showed relatively long-term stability with only slight particle growth (P>0.05) after storage at room temperature for 4 weeks. Therefore, ultrasonication is demonstrated to be a simple, available and effective method to prepare high quality SLN loaded probiotic material.

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남북한 과학기술협력의 새로운 방향: 지역 혁신체제론의 시각에서

  • 정선양
    • Journal of Technology Innovation
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    • v.9 no.2
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    • pp.77-97
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    • 2001
  • The 21st century is not only the knowledge-based society but also the unifie era for Korea. It implies that Korea should prepare for the unification, especially in the area of knowledge, science, and technology. Under this background, this paper deals with how we can prepare for the unification of South and North Korea in science and technology (S&T) area. There have been no sufficient theoretical studies in this area. This paper, therefore, argues that regional innovation system, which has been developed since the beginning of the 1990s, could be effectively applied to the S&T cooperation and unification between both Koreas. It argues that regional innovation systems can formulate sectoral innovation systems effectively, which lead to a competent national innovation system. According to this study, South and North Korean regions have complementary sectoral innovation systems that could effectively cooperate with each other. Such S&T cooperation could make a great contribution to the S&T integration between two Koreas in the future. This paper argues, therefore, that S&T cooperation between two Koreas should target the unification of South and North Korean regional innovation systems. This paper names it as the unified national innovation system.

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Technology Trends to High Efficiency Motors : Focused on Induction Motor (고효율 전동기 기술 동향 : 유도기 중심으로)

  • Jang, Kibong
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.6
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    • pp.995-1000
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    • 2016
  • Minimum Energy Performance Standard(MEPS) has been adapted in Korea since 2008. For at least 37 kW, IE3 efficiency class motors are now mandatory in Korea. IE4 level regulation is expected in a few years. Foreign companies are already selling IE4 class motors in the market, and the discussions on IE5 have already started. The efficiency standard of variable speed motors is scheduled for publication shortly. Recently, discussions are now beginning to prepare for IE5 in Korea. In this paper, author reviews the policies associated with a high efficent electric motors by reference to both domestic and international standards, and reviews the research direction to prepare for IE5.

Formation of Quantum Dot Fluorescent Monolayer Film using Peptide Bond

  • Inami, Watau;Nanbu, Koichi;Miyakawa, Atsuo;Kawata, Yoshimasa
    • Transactions of the Society of Information Storage Systems
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    • v.8 no.1
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    • pp.1-5
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    • 2012
  • We present a method for preparing a quantum dot fluorescent monolayer film on a glass substrate. Since nanoparticles aggregate easily, it is difficult to prepare a nanoparticle monolayer film. We have used a covalent bond, the peptide bond, to fix quantum dots on the glass substrate. The surface of the quantum dot was functionalized with carboxyl groups, and the glass substrate was also functionalized with amino groups using a silane coupling agent. The carboxyl group can be strongly coupled to the amino group. We were able to successfully prepare a monolayer film of CdSe quantum dots on the glass substrate.

Evaluation of Rapid Immunochromatographic Assay Kit for HBsAg-Screening Using Whole Blood

  • Shin, Hyeong-Soon;Heo, Tae-Ryeon
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.5 no.5
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    • pp.362-365
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    • 2000
  • A rapid immunochromatographic assay kit using whole blood to screen hepatitis B surface antigen was developed and evaluated by using sera from 240 patients. The reference diagnosis was based on the results obtained with GENEDIA Anti-HBs Rapid kit which is very similar to the above kit except for the use of serum. The test demonstrated a good correlation with the reference immunochromatographic assay kit, that is, the sensitivity and the specificity of the kit was 100%, respectively. The rapid test kit using whole blood should be more convenient and useful for the diagnosis of hepatitis B virus because the kit does not need machines and time to prepare serum. In addition, this kit is safe from inadvertent infection during sample treatment because the blood is sterilized with hydrogen peroxide, eliminates the procedure required to prepare serum and reduces the possibility of exposure to infectious agents.

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Study on Electrical and Thermal Properties of Poly(3,4-ethylenedioxythiophene)-coated Polycarbonate Fi1ms (Poly(3,4-ethylenedioxythiophene)으로 코팅된 Polycarbonate 필름의 전기적 특성과 열적 특성에 관한 연구)

  • Sangsoo Jeon;Seungsoon Im
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10b
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    • pp.169-170
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    • 2003
  • There was little development in transparent conductive polymer films and their limited studies have been mainly focused on polymer films coated by water-soluble PEDOT doped with the polymeric counteranion poly(4-styrenesulfonate) (PEDOT-PSS)[1-3]. However PEDOT-PSS as coating material has some difficulties because of high viscosity and low solubility in organic solvent except for in water. In this study, in order to extend practical applications of PEDOT and to prepare conductive PC films, we tried to prepare PEDOT-coated PC films and investigated their conductivity and thermal stability. (omitted)

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A Study on the Development and Application of Thermal Evaporation Source (Thermal Evaporation 증발원 개발 및 응용에 관한 연구)

  • Kim, Kwan-Do
    • Journal of the Semiconductor & Display Technology
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    • v.19 no.3
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    • pp.19-22
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    • 2020
  • The thermal evaporation source is used to prepare thin films by physical vapor deposition. Materials of metals, organic materials, were tested and explained for thermal evaporation experiments. The developed effusion cell performance depends on the type of deposition material, the size of the crucible, the performance of the reflector, etc. and the proper conditions were found by producing, comparing and analyzing several sets of effusion cell to quantitatively evaluate the performance of the cell. The effusion cell for thermal evaporation source is used to prepare thin films of Ag, Cu, Mg.

Lipase Mediated Chiral Resoulution of 4-Arylthio-2-Butanol as an Intermediate for $\beta-Lactam$ Antibiotics

  • Hwang, Kwang-Jin;Lee, Jinkue;Chin, Sung-Min;Moon, Chi-Jang;Lee, Won-Jae;Baek, Chae-Sun;Kim, Hyung-Jin
    • Archives of Pharmacal Research
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    • v.26 no.12
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    • pp.997-1001
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    • 2003
  • This paper deals with chiral enzymatic resolution of 4-arylthio-2-butanols by lipase to prepare potential intermediates of $\beta$-lactam antibiotics. Among several lipases employed, lipase P type enzyme gave the highest ee value to prepare (R)-4-arylthio-2-butyl acetate. The enzymatic resolution of phenyl substituted alcohol (6a) using lipase P showed the highest ee value (99.7%) among those of 4-arylthio-2-butanol derivatives. Lipase P mediated hydrolysis of acylester 7a gave also (R)-alcohol 6a selectively. For determination of enantiomeric purity of these enzymatic resolved analytes, liquid chromatographic analysis was performed using two coupled Chiralcel OD and (R,R)-WhelkO chiral column.