• 제목/요약/키워드: MDI

검색결과 253건 처리시간 0.025초

Synthesis and Hydrogen Adsorption Properties of Porous Polymer

  • Wang, Qi;Liu, Jin;Zhang, Jing;Oh, Won-Chun
    • 한국재료학회지
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    • 제26권6호
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    • pp.332-336
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    • 2016
  • Three kinds of porous polymer were synthesized using a solvothermal of tri-4,4'-diphenylmethane diisocyanate (MDI-trimer) and different diamino monomers. The effects of the synthesis conditions and the monomer selection on the synthesis of porous polymer properties were studied. The results show that the synthesis of $NH_2$-containing monomer molecules smaller the microporous polymers was easy to implement; the specific surface areas of the polymers are related to the monomer ratio and the reaction time. The results show that the synthesized porous polymer had good hydrogen storage performance; the hydrogen storage ability improved with the addition of heterocyclic nitrogen.

EXACT SOLUTIONS OF THE MDI AND SAWADA-KOTERA EQUATIONS WITH VARIABLE COEFFICIENTS VIA EXP-FUNCTION METHOD

  • Zhang, Sheng;Abdou, M.A.
    • Journal of applied mathematics & informatics
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    • 제28권1_2호
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    • pp.143-152
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    • 2010
  • Based on the Exp-function method and a suitable transformation, new generalized solitonary solutions including free parameters of the MDI and Sawada-Kotera equations with variable coefficients are obtained, form which solitary wave solutions and periodic solutions including some known solutions reported in open literature are derived as special cases. The free parameters in the obtained generalized solitonary solutions might imply some meaningful results in the physical models. It is shown that the Exp-function method provides a very effective and important new method for nonlinear evolution equations with variable coefficients.

Recent Advances and Trends in Reactive Polyurethane Adhesives

  • Krebs, Michael
    • 접착 및 계면
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    • 제7권4호
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    • pp.53-59
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    • 2006
  • The paper highlights technical advances and introduces recent innovations such as smart curing laminating adhesives for flexible packaging with low migration rates of aromatic isocyanates and amines. Latent reactive one-part systems on the basis of surface deactivated solid isocyanates open up new dimensions for heat setting adhesives and waterborne PU dispersions. The new generation of Purmelt Micro Emission adhesives contains less than 0.1% of MDI monomer, thereby drastically reducing the emission of hazardous isocyanate vapors during processing and setting a significantly improved technical standard in occupational safety. Once again, polyurethane adhesives have demonstrated their unique ability to adapt to new process, product, safety and environmental requirements.

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Evaluation of Attribute Selection Methods and Prior Discretization in Supervised Learning

  • Cha, Woon Ock;Huh, Moon Yul
    • Communications for Statistical Applications and Methods
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    • 제10권3호
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    • pp.879-894
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    • 2003
  • We evaluated the efficiencies of applying attribute selection methods and prior discretization to supervised learning, modelled by C4.5 and Naive Bayes. Three databases were obtained from UCI data archive, which consisted of continuous attributes except for one decision attribute. Four methods were used for attribute selection : MDI, ReliefF, Gain Ratio and Consistency-based method. MDI and ReliefF can be used for both continuous and discrete attributes, but the other two methods can be used only for discrete attributes. Discretization was performed using the Fayyad and Irani method. To investigate the effect of noise included in the database, noises were introduced into the data sets up to the extents of 10 or 20%, and then the data, including those either containing the noises or not, were processed through the steps of attribute selection, discretization and classification. The results of this study indicate that classification of the data based on selected attributes yields higher accuracy than in the case of classifying the full data set, and prior discretization does not lower the accuracy.

불소화된 폴리우레탄의 기계적 물성과 혈소판 점착특성에 관한 연구 (A Study for Mechanical and Platelet Adhesion Properties of Fluorinated Polyurethanes)

  • 김형중
    • 폴리머
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    • 제25권3호
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    • pp.343-348
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    • 2001
  • Perfluorinated polyether diol(Fomblin ZDOL$ZDOL^{(R)}$)과 4,4'-diphenyl methane diisocyanate(MDI)로부터 합성된 불소화된 폴리우레탄 탄성체의 기계적 성질과 혈소판 점착 특성을 연구하였다. Fomblin 함량과 혼합 사용된 polyether polyol의 종류에 따른 기계적 성질의 검토를 인장실험 및 dynamic mechanical analysis를 통해 행하였다. 또한 혈소판 점착실험을 통해 불소화된 폴리우레탄 탄성체의 혈액적합성을 평가하였다. 기계적 물성은 혼합된 polyether polyol의 종류와 함량에 영향을 받았고, 혈소판 점착은 모든 불소화된 폴리우레탄에서 불소화 함량의 증가에 따라 감소하였다.

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On an Information Theoretic Diagnostic Measure for Detecting Influential Observations in LDA

  • Kim, Hea-Jung
    • Journal of the Korean Statistical Society
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    • 제25권2호
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    • pp.289-301
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    • 1996
  • This paper suggests a new diagnostic measure for detecting influential observations in two group linear discriminant analysis(LDA). It is developed from an information theoretic point of view using the minimum discrimination information(MDI) methodology. MDI estimator of symmetric divergence by Kullback(l967) is taken as a measure of the power of discrimination in LDA. It is shown that the effect of an observation over the power of discrimination is fully explained by the diagnostic measure. Asymptotic distribution of the proposed measure is derived as a function of independent chi-squared and standard normal variables. By means of the distributions, a couple of methods are suggested for detecting the influential observations in LDA. Performance of the suggested methods are examined through a simulation study.

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