• Title/Summary/Keyword: ?, 1723)

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An Infrared Study of Complexes of Methylmethacrylate with Cations on the Interlamdellar Surfaces of Layer Silicates (赤外線分光法에 의한 層狀硅酸鹽의 層間表面上의 陽이온과 Methylmethacrylate의 錯物 硏究)

  • Kim Jong Taik;Sohn Jong Rack
    • Journal of the Korean Chemical Society
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    • v.21 no.4
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    • pp.246-255
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    • 1977
  • The adsorption of methylmethacylate on layer silicates containing various interlayer cations has been studied by means of infrared spectroscopy and X-Ray. Several characteristic carbonyl bands of adsorbed methylmethacrylate appeared differently at the region of 1723∼1547$cm^{-1}$depending on the species of cation and the dehydration temperature. The carbonyl stretching band shifted about 190$cm^{-1}$ to lower frequencies has been observed only for polyvalent cations, which has been attributed to $>C=O{\cdot}{\cdot}{\cdot}M^{n+}$ complex formation. The band appeared at 1703∼1640$cm^{-1}$ is responsible for hydrogen bonding between carbonyl oxygen and cationic water or cationic hydroxyl group, and the degree of shift indicates good correlation with the polarizing power of the interlayer cations. However, the band appeared at 1723$cm^{-1}$ has not been correlated with the species of cation but assigned to the carbonyl stretching which reacted with the surface hydroxyl group. On the basis of interlamellar spacing, it is suggested that the molecular plane of MMA molecule is parallel to silicate layers.

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Fractional Diffusion Equation Approach to the Anomalous Diffusion on Fractal Lattices

  • Huh, Dann;Lee, Jin-Uk;Lee, Sang-Youb
    • Bulletin of the Korean Chemical Society
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    • v.26 no.11
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    • pp.1723-1727
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    • 2005
  • A generalized fractional diffusion equation (FDE) is presented, which describes the time-evolution of the spatial distribution of a particle performing continuous time random walk (CTRW) on a fractal lattice. For a case corresponding to the CTRW with waiting time distribution that behaves as $\psi(t) \sim (t) ^{-(\alpha+1)}$, the FDE is solved to give analytic expressions for the Green’s function and the mean squared displacement (MSD). In agreement with the previous work of Blumen et al. [Phys. Rev. Lett. 1984, 53, 1301], the time-dependence of MSD is found to be given as < $r^2(t)$ > ~ $t ^{2\alpha/dw}$, where $d_w$ is the walk dimension of the given fractal. A Monte-Carlo simulation is also performed to evaluate the range of applicability of the proposed FDE.

A Study of Multi-Channel Internet Radio Platform (Multi-Channel Internet Radio Platform에 대한 연구)

  • Kim, Jong-Duk;Kim, Toung-Kil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.7
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    • pp.1723-1728
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    • 2010
  • In this paper we concentrate design and develop method about Multi-Channel Internet Radio Platform to broadcast music contents in large outlet and between spaces to protect music contents which have drastically widespread demage. we provide application concept and design rule of hardware path for Multi-Channel Connection and Multi Stream.

Purification ana properties of alkaline pretense produced by Bacillus sp. KCTC 1723

  • 정영희;민영희;고영희
    • Proceedings of the Korean Society for Applied Microbiology Conference
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    • 1986.12a
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    • pp.532.2-532
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    • 1986
  • Alkaline protease which is an important enzyme used in detergents, leather tanning and food industry was produced by alkalophilic bacterium, Bacillus sp. KCTC 1723 isolated from soil. The maximum productivity of the enzyme in alkaline medium containing 1% sodium bicarbonate was obtained by incubating for 3 days at 37$^{\circ}C$. The optimum pH of the enzyme was 11.5 and calcium ion was effective on stabilization of the enzyme at high temperature. The enzyme was not inhibited by metal chelating agent such as El)TA but inhibited by diisopropyl fluorophosphate. Purification of the enzyme was carried out DEAE- and CM-cellulose column chromatographies and molecular weight of the purified enzyme was determined

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Research Progress in Potential Urinary Markers for the Early Detection, Diagnosis and Follow-up of Human Bladder Cancer

  • Wang, Hai-Feng;Wang, Jian-Song
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.5
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    • pp.1723-1726
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    • 2012
  • Objective: To summarize and evaluate various urinary markers for early detection, diagnosis and follow-up of human bladder cancer. Methods: A MEDLINE and PUBMED search of the latest literature on urinary markers for bladder cancer was performed. We reviewed these published reports and made a critical analysis. Results: Most urinary markers tend to be less specific than cytology, yielding more false-positive results, but demonstrating an advantage in terms of sensitivity, especially for detecting low grade, superficial tumors. Some tumor markers appear to be good candidates for early detection, diagnosis, and follow-up of human bladder cancer. Conclusion: A number of urinary markers are currently available that appear to be a applicable for clinical detection, diagnosis, and follow-up of bladder cancer. However, further studies are required to determine their accuracy and widespread applicability.

Synthesis and Anti-HIV-1 Activity of Carbocyclic Versions of Stavudine Analogues Using a Ring-closing Metathesis

  • Liu, Lian-Jin;Ko, Ok Hyun;Hong, Joon-Hee
    • Bulletin of the Korean Chemical Society
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    • v.29 no.9
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    • pp.1723-1728
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    • 2008
  • An efficient synthetic route for carbocyclic versions of stavudine analogues and their evaluation on antiviral activity are described. The construction of an ethynylated quaternary carbon at the 4'-position of carbocyclic nucleosides was accomplished using Claisen rearrangement of 11 and ring-closing metathesis (RCM) of dienyne 14 as key transformations. An antiviral evaluation of the synthesized compounds, 20, 21, 22, and 25 against HIV-1, HSV-1, HSV-2, and HCMV showed that only the guanine analogue 25 is moderately active against HIV-1 in the MT-4 cell line ($EC_{50}$ = 11.91 $\mu$mol).

A Theoretical Study on Voltage Drop of Auto-Transformer for Railway Vehicle Base (철도차량기지용 단권변압기의 전압강하에 대한 이론적 고찰)

  • Yu, Ki-Seong;Kim, Jae-Moon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.12
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    • pp.1723-1728
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    • 2018
  • In order to investigate the voltage drop compensation effect of AT for domestic railway vehicle base, the parameters of AT voltage drop of railroad car base are Z3 (Impedance of feeder line), Xn ( Distance from railroad vehicle to AT to SS), and Dn (distance between both ATs of railway vehicle).In addition, when installed in a SSP for a railway vehicle base, there is no AT and feeder line in the railway vehicle base except for the SSP for the main line and the SSP for the railway vehicle base, so that if zero or ignored, the AC single-phase two- It can be confirmed that it becomes a form.