Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1432-0487
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Description / Table of Contents: Contents If 3-dimensional electromagnetic problems are solved by finite elements, the computation of the fields for problems involving infinite space causes difficulties. To treat such problems either infinite elements [1] or so called ‘ballooning elements’ [2] can be used. Another possibility is the coupling of finite elements and boundary elements. In this article the calculation of electrostatic and magnetostatic fields in infinite space is presented, utilizing coupled elements. The problems are formulated in terms of potentials. In the electrostatic case the scalar potential ϕ and in the magnetostatic case the vector potentialA is used. To investigate the capability of the coupled elements, among other things two examples have been calculated and compared to their solutions gained with the help of Biot-Savart's law.
    Notes: Übersicht Will man elektromagnetische Probleme, die auf unendlichen Grundgebieten definiert sind, mit Hilfe der Methode der finiten Elemente lösen, so bereitet die Berücksichtigung der unendlichen Grundgebiete Schwierigkeiten. Um diese Schwierigkeiten zu überwinden, kann man beispielsweise zusätzlich infinite Elemente [1] oder sog. “Ballooning-Elemente” [2] verwenden. Eine andere Möglichkeit ist die Kopplung der Methode der finiten Elemente mit der Randelementmethode [4]. In diesem Artikel wird die Berechnung elektrostatischer und magnetischer Felder im unendlichen Raum mit Hilfe einer solchen Hybridmethode vorgestellt. Die Probleme werden entweder mit dem skalaren elektrischen Potential ϕ oder mit dem magnetischen Vektorpotential A formuliert. Um die Leistungsfähigkeit des Hybridansatzes zu untersuchen, werden u. a. zwei Beispiele behandelt, und deren Ergebnisse werden mit den nach dem Biot-Savart'schen Gesetz gewonnenen Lösungen vergleichen.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1435-1536
    Keywords: Key words Alkyl maleates ammonium derivatives ; surfactants ; 1H NMR ; CMC ; emulsion polymerization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract  The synthesis of several ammonium derivatives of maleic acid diesters are reported. The starting material is the hemiester of maleic acid, easily obtained from ring opening of the maleic anhydride. The hemiester is submitted to functionalization with an aminated compound, followed by quaternari-zation with the convenient alkylation reagent. Products crystallize easily and yields are generally high. They have been fully characterized by 1H and 13C NMR and the CMC have been measured. Some of them have been engaged in emulsion polymerization with styrene or methyl methacrylate. Maleates functionalized with quaternary ammonium salts yield polystyrene particle sizes around 30 nm with a narrow size distribution without adding any additional emulsifier.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Macromolecular Rapid Communications 19 (1998), S. 397-402 
    ISSN: 1022-1336
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A new type of reactive surfactant, containing both a methacrylic and a maleic group, was prepared and engaged in batch and seeded emulsion polymerization of styrene and styrene-butyl acrylate. The stability of core-shell latexes versus electrolytes has been studied.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...