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  • 1
    Electronic Resource
    Electronic Resource
    Semilattice-based dualities (1996)
    Springer
    Studia logica 56 (1996), S. 225-261 
    Details
    ISSN: 1572-8730
    Keywords: Priestley duality ; Stone duality ; Pontryagin duality ; character group ; program semantics ; Bochvar Logic ; regular identities
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Philosophy
    Notes: Abstract The paper discusses “regularisation” of dualities. A given duality between (concrete) categories, e.g. a variety of algebras and a category of representation spaces, is lifted to a duality between the respective categories of semilattice representations in the category of algebras and the category of spaces. In particular, this gives duality for the regularisation of an irregular variety that has a duality. If the type of the variety includes constants, then the regularisation depends critically on the location or absence of constants within the defining identities. The role of schizophrenic objects is discussed, and a number of applications are given. Among these applications are different forms of regularisation of Priestley, Stone and Pontryagin dualities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00370148
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  • 2
    Electronic Resource
    Electronic Resource
    Automated fuzzy knowledge acquisition with connectionist adaptation (1996)
    Springer
    Neural computing & applications 4 (1996), S. 27-34 
    Details
    ISSN: 1433-3058
    Keywords: Fuzzy logic ; Genetic algorithms ; Knowledge acquisition ; Learning ; Neural networks ; Optimisation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mathematics
    Notes: Abstract This paper presents an automated knowledge acquisition architecture for the truck docking problem. The architecture consists of a neural network block, a fuzzy rule generation block and a genetic optimisation block. The neural network block is used to quickly and adaptively learn from trials the driving knowledge. The fuzzy rule generation block then extracts the driving knowledge to form a knowledge rule base. The driving knowledge rule base is further optimised in the genetic optimisation block using a genetic algorithm. Computer simulations are presented to show the effectiveness of the architecture.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01413867
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  • 3
    Electronic Resource
    Electronic Resource
    Synthesis and properties of model oligomers of poly(naphthylenevinylene)s (1989)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 190 (1989), S. 2995-3003 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Model compounds for poly(1,4-naphthylenevinylene) (1) and poly(2,6-naphthylenevinylene) (2) were synthesized by the Wittig synthesis and studied by UV/VIS spectroscopy and cyclic voltammetry. The values of 2,0 eV for the band gap edge and 0,7 V vs. the saturated calomel electrode for the oxidation potential, which were estimated by an extrapolation of the band gap edge and oxidation potential of model dimer and trimer of 1, are in excellent agreement with the literature values for the polymer. A value of 2,3 eV for the band gap edge of 2 was found by extrapolating the band gap edge of a model dimer and trimer, but the oxidation potential of polymer 2 could not be estimated, because the model trimer was not sufficiently soluble in solvents used. The stoichiometries of the radical cation salts of the model compounds, which were prepared by electrocrystallization, were evaluated from elemental analysis. A single crystal, radical cation salt was obtained for the model dimer of polymer 2.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1989.021901130
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  • 4
    Electronic Resource
    Electronic Resource
    Metal acetylacetonates as latent accelerators for anhydridehyphen;cured epoxy resins (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 26 (1981), S. 979-986 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Twenty-two metal acetylacetonate compounds have been evaluated as possible latent accelerators for epoxy-anhydride solventless resins. Experimental data have revealed that titanium (IV) oxyacetylacetonate, chromium (III), zirconium (IV), cobalt (III), and cobalt (II) acetylacetonates are particularly effective with anhydride cured epoxy resins. When added to the resin at a level of 0.05-0.10% (w/w), they provide very fast gel times at 150-175°C combined with very good storage stabilities (〉 six months) at room temperature. The power factor values of cured resin samples, containing these preferred metal acetylacetonates, have been found to be between 2.0 and 2.5% at 150°C and 60 Hz. Correlation between the catalytic effectiveness of these metal acetylacetonates, as latent accelerators for epoxy-anhydride resins, and their thermal stabilities suggest that decomposition products may be the active species responsible for initiating polymerization in epoxyanhydride resin systems.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1981.070260320
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  • 5
    Electronic Resource
    Electronic Resource
    Poly[(4-N-ethylene-N-ethylamino)-α-cyanocinnamate]: A nonlinear optical polymer with a chromophoric mainchain. I. Synthesis and spectral characterization (1991)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 29 (1991), S. 1623-1631 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Poly[(4-N-ethylene-N-ethylamino)-α-cyanocinnamate] was prepared by solution esterification of (4-N-ethyl-N-(2-hydroxyethyl) amino)-α-Cyanocinnamic acid and by melt transesterification of ethyl (4-N-ethyl-N-(2-hydroxyethyl) amino)-α-cyanocinnamate. The melt transesterification generally yielded polymer with a number-average molecular weight of about 10,200 by gel permeation chromatography (GPC) versus polystyrene standards. The polymer was found to be amorphous with a glass transition temperature of about 103°C by differential scanning calorimetry (DSC). The solution esterification generally gave a polymer with a number-average molecular weight of about 2200 by GPC versus polystyrene standards. This polymer was found to have a glass transition temperature varying between 60 and 90°C by DSC. The infrared (IR) spectrum of the polymer made from both methods were analyzed in detail. The 1H- and 13C-NMR spectra of the meltsynthesized ethyl cinnamate derivative polymer are consistent with the reported structure.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1991.080291112
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  • 6
    Electronic Resource
    Electronic Resource
    Main-chain, syndioregic, high-glass transition temperature polymer for nonlinear optics: Synthesis and characterization (1993)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 31 (1993), S. 2899-2906 
    Details
    ISSN: 0887-624X
    Keywords: high-glass transition temperature nonlinear optical polymer ; syndioregic ; mainchain chromophore ; accordion polymers ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new main-chain syndioregic (head-to-head) NLO polymer was synthesized. The glass transition temperature of high molecular weight polymer was found to be 208°C, and the polymer has minimal weight loss at temperatures to at least 250°C owing to the incorporation of hydrogen bonding moieties and rigid bridging groups. The polymer was further characterized using nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR). The study of the nonlinear optical properties of this polymer are in progress. © 1993 John Wiley & Sons, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1993.080311203
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  • 7
    Electronic Resource
    Electronic Resource
    Laser-Initiated copolymerization of N-vinylpyrrolidone with maleic anhydride and maleimide (1992)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 30 (1992), S. 589-595 
    Details
    ISSN: 0887-624X
    Keywords: laser copolymerization ; charge transfer complexes ; N-vinylpyrrolidone ; maleic anhydride ; maleimide ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: This article describes the laser-initiated copolymerization of N-vinylpyrrolidone with maleic anhydride and maleimide via charge transfer complexes. The dependence of copolymer yield on the molar ratios of the monomers in the feed and on the irradiation time is described. Based on the ultraviolet and infrared spectroscopy, and chemical analysis results, a tentative mechanism of polymerization is suggested. The rates of polymerization of several monomer systems are compared. The N-vinylpyrrolidone and maleimide system shows the highest rate of polymerization.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1992.080300410
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  • 8
    Electronic Resource
    Electronic Resource
    The electroinitiated polymerization of N-vinylcarbazole with zinc bromide, IIPart I: cf.12.. Kinetics of polymerization (1973)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 169 (1973), S. 177-189 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die elektroinitiierte Polymerisation von N-Vinylcarbazol (VCZ) wurde in Aceton bei 25°C mit Zinkbromid als Katalysator unter Verwendung von Platinelektroden eingehend untersucht. Die Polymerisationsgeschwindigkeit erwies sich als direkt abhängig von der Stromstärke, der Zinkbromid-Konzentration und dem anfänglichen Wassergehalt des Solvens.Die Molekulargewichte der entstandenen Polymeren (1000-6000) sind unabhängig von der Stromstärke, der Zinkbromid-Konzentration und dem Umsetzungsgrad des Monomeren zum Polymeren, werden jedoch beeinflußt durch Wasser, die Monomerkonzentration und das Elektrodenmaterial. Die chemische Zusammensetzung der Polymeren ändert sich nicht mit der Stromstärke, der Zinkbromid-Konzentration, dem Umsetzungsgrad und dem Elektrodenmaterial. Sie ändert sich jedoch ein wenig mit dem Wassergehalt des Acetons.
    Notes: The electroinitiated polymerization of N-vinylcarbazole (VCZ) in acetone solvent at 25°C with zinc bromide, as catalyst, and platinum electrodes was investigated in detail. The polymerization rate was found to be directly dependent on current strength, zinc bromide concentration and the initial water content of the solvent.The molecular weights of the formed polymers (1000-6000) are independent of current strength, zinc bromide concentration and degree of conversion of monomer to polymer, but are affected by water, monomer concentration, and by the type of electrodes used. The chemical composition of the polymer is invariant with current strength, zinc bromide concentration, degree of conversion, and electrode material but does vary slightly with the water content of acetone.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1973.021690117
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  • 9
    Electronic Resource
    Electronic Resource
    Kinetic studies on anaerobic initiated polymerization (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 45 (1992), S. 1-15 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Using a model reaction system consisting of cumene hydroperoxide, N,N-dimethyl-p-to-luidine and O-benzoic sulfimide in toluene solvent (without reactive acrylic monomer), attempts have been made to understand the initiation mechanism operating during anaerobic polymerization. In these studies, the instrumental techniques of visible spectroccopy (VS), high performance liquid chromatography (HPLC) and infrared spectroscopy (IR) were employed.Valuable kinetic data have been obtained using these three instrumental techniques. HPLC studies have shown conclusively that the N,N-dimethyl-p-toluidine (N,N-DMpT) component is significantly depleted during the initiation step of the anaerobic process. By way of contrast, the benzoic sulfimide (BS) concentration was found to be essentially unchanged during initiation.Visible spectral changes with the model anaerobic solutions indicate that the initiation mechanism may involve radical-ionic species derived from N,N-DMpT rather than free radical reactive intermediates. Increasing the acidity of the reaction solution, with addition of acetic acid, appears to accelerate the initiation rate under anaerobic conditions.
    Additional Material: 20 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1992.070450101
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  • 10
    Electronic Resource
    Electronic Resource
    Quaternary phosphonium compounds as latent accelerators for anhydride-cured epoxy resins. I. Latency and cure characteristics (1979)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 23 (1979), S. 1385-1396 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Quaternary phosphonium compounds have been found to be extremely effective latent accelerators for anhydride-cured bisphenol A epoxy resins; at concentrations from 0.01% to 0.25%, fast gel times are found in the temperature range of 135°-200°C combined with very good storage properties at ambient temperatures. Using these materials as accelerators, it is possible to formulate long-life, one-component epoxy resins. From gel time data, Arrhenius plots were made for some of these phosphonium compounds, and results indicate low activation energy values of the order of 16.1 kcal/mole. Reaction mechanisms are proposed to explain the effectiveness of these phosphonium compounds as latent accelerators. The initiation mechanism probably involves the formation of hydrogen-bonded phosphonium-epoxy or phosphonium-anhydride complexes which rearrange on the application of heat to form activated species resulting in polymerization of the epoxy-anhydride components. The transfer of a proton from the phosphonium complex(es) to other epoxy or anhydride molecules would appear to be the rate-determining step in this initiation mechanism. Comparison of other well-known accelerators used for the anhydride cure of bisphenol A epoxy resins shows quaternary phosphonium compounds to be among the most effective accelerators disclosed to date.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1979.070230510
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