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Wyznaczanie kierunku i wartości wektora natężenia pola elektrycznego za pomocą metody wykorzystujących elektrooptyczny efekt Kerra

Kasprzak W., Nadolny Z.

Przegląd Elektrotechniczny

2012

R. 88, nr 5a

47-50

W artykule przedstawiono nowatorską metodę wyznaczania kierunku i wartości wektora natężenia pola elektrycznego na powierzchni wysokonapięciowych układów izolacyjnych. Metoda ta jest oparta na elektrooptycznym efekcie Kerra. Opracowana metoda jest pozbawiona wad metod tradycyjnych. Oznacza to, że nie ingeruje znacząco w rozkład pola elektrycznego, oraz nie uśrednia wartości jego natężenia. Przykładowym obiektem badań był długopniowy kompozytowy izolator liniowy na napięcie 220 kV.

The paper presents innovative method to estimate the direction and value of electric field stress vector on surface of high voltage insulation systems. The method is based on electro-optic Kerr effect. Elaborated method is free from disadvantages of traditional methods. It means, that the method does not change significantly electric field distribution, and does not average its values. Long-rod composite high voltage 220 kV insulator was object of the investigations.

Elektrooptyczny efekt Kerra w chemii

Prezhdo O., Olan K., Zubkowa W., Preżdo W.

Wiadomości Chemiczne

2011

[Z] 65, 1-2

1-31

The electro-optical Kerr effect finds wide application in conformational analysis of molecules and molecular aggregates [1–5], particularly in cases where the standard X-ray and NMR techniques cannot be used. For instance, NMR allows to establish conformations of linear and cyclic unsaturated organic compounds. However, it is less effective in an analysis of molecular complexes, particularly of those that have several rotational symmetry axes. In such cases a combination of techniques based on molecular dipole moments, electro-optical Kerr effect, optical Kerr effect, IR spectroscopy, and Rayleigh scattering can be applied [6]. The foundations of conformational analysis of molecular complexes using several complementary physical approaches are developed in Ref. [7]. The electro-optical methods are particularly useful for an investigation of intramolecular interactions [8–18]. The strength, direction and other details of intramolecular interactions can be determined by analyzing the deviations of the experimental molar Kerr constant (mK) from its value calculated according to the tensor-additive scheme that operates with polarizability tensors of molecular cores and functional groups [19, 20]. For instance, using this approach it has been shown that weakening of conjugation in an electron donor-acceptor chain can lead to flattening of the molecular structure [21]. The Kerr constant is also very sensitive to intermolecular interactions [22–29]. In order to assess quantitatively an extent of the solvent effect on the mK values, both molecular and continuum models of solution structure have been used [30, 31]. The mK values are greatly affected by the mutual orientation of solvent and solute molecules, which interact by dispersive, inductive and dipole-dipole forces [32]. Hydrogen and donor-acceptor bonding have an even stronger influence on the mK values [33]. The equimolar mixtures approach developed in Ref. [34] allows to determine the molar Kerr constant (mK), dipole moment (m), equilibrium constant (K) and, ultimately, structure of a molecular complex based on measurements of the Kerr constant (B), dielectric permittivity (e), density (d) and refractive index (n) of a series of dilute solutions of the complex. Future trends in the development of the electro-optical methods in chemistry are discussed. Theories that relate the electric-optic proprieties of molecules with their reactivity are particularly important. Such theories should be able to predict the changes in the polarizabilities and dipole moments of bonds, molecules and molecular aggregates during the course of chemical reactions.