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Influence of Radiation on the Dielectric Properties of XLPE Based Insulation Systems

References ZAENGL, W. S.: Dielectric Spectroscopy in Time and Frequency Domain for HV Power Equipment, 12th Internat. Symposium on High Voltage Engineering - ISH 2001, Bangalore, India, 20-24 August 2001, 1-10. COLE, K. S.—COLE, R. H.: Dispersion and Absorption in Dielectrics, I. Alternating Current, J. Phys. Chem. No. 9 (1941), 341-351. HAVRILIAK, S.—NEGAMI, S.: A Complex Plane Analysis of -Dispersions in Some Polymer Systems, J. Polymer Sci. C 14 (1966), 99

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Dielectric properties and molecular motions of liquid crystal molecules in 4-(2-methylbytyl)phenyl 4-(4-octylphenyl)benzoate liquid crystal having blue phase (CE8)

., 98 (8) (2011), 081109. [7] LEE H., PARK H.J., KWON O.J., YUN S.J., PARK J.H., HONG S., SHIN S.T., SID Int. Symp. Dig. Tec., 42 (2011), 122. [8] MEIBOOM S., SETHNA J.P., ANDERSON W.P., BRINKMAN W.F., Phys. Rev. Lett., 46 (1981), 1216. [9] OTOWSKI W., Molecular motion in liquid crystals as seen via dielectric spectroscopy, in: GALEWSKI Z., SOBCZYK L. (Eds.), Dielectric Properties of Liquid Crystals, Transworld Research Network, Kerala, India, 2007, pp. 1 - 35. [10] CAVA R.J., PATEL J.S., RIETMAN E.A, J

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Surface characterization of clay particles via dielectric spectroscopy

Surface characterization of clay particles via dielectric spectroscopy

This work deals with the high frequency dielectric relaxation of clay (sodium montmorillonite, or NaMt) suspensions. By high frequency it is meant that the permittivity will be determined in the region where the Maxwell-Wagner-O'Konski relaxation takes place, roughly, the MHz frequency range. The applicability of dielectric determinations for the characterization of the electrical properties of these complex systems is demonstrated. In fact, standard electrophoresis measurements only allow to detect that the charge of the particles becomes slightly more negative upon increasing pH. Much more information is obtained from the high frequency electric permittivity for different concentrations of solids and pHs. From the characteristic frequencies of the relaxation it is possible to detect separate processes for parallel and perpendicular orientations of the clay platelets, modelled as oblate spheroids with a high aspect ratio. In addition, using a suitable model the surface conductivity of the clay particles can be estimated. Our data indicate that this quantity is minimum around pH 7, which is admitted as representative of the isoelectric point of the edges of the clay platelets. Data are also obtained on the amplitude (value of the relative permittivity at low frequency minus that at high frequency) of the relaxation, and it is found that it depends linearly on the volume fraction of solids, and that it is minimum at pH 5. These results are considered to be a manifestation of the fact that particle interactions do not affect the electric conduction inside the electric double layer, while the special behaviour at pH 5 is related to the existence of aggregates at pH 5, which increase the effective size of the particles and provoke a reduction of their effective conductivity.

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Structural analysis and dielectric relaxation mechanism of conducting polymer/volcanic basalt rock composites

Abstract

In this work, polypyrrole and polythiophene conducting polymers (CPs) have been synthesized and doped with volcanic basalt rock (VBR) in order to improve their dielectric properties for technological applications. The structure and morphology of the composites with different VBR doping concentrations were characterized by FT-IR and SEM analyses. The best charge storage ability was achieved for maximum VBR doping concentration (50.0 wt.%) for both CPs. Dielectric relaxation types of the composites were determined as non-Debye type due to non-zero absorption coefficient and observation of semicircles whose centers were below Z′ axis at the Nyquist plots. It was also ascertained that VBR doping makes the molecular orientation easier than for non-doped samples and reduced energy requirement of molecular orientation. In addition, AC conductivity was totally masked by DC conductivity for all samples at low frequency.

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Influence of Bi on dielectric properties of GaAs1−xBix alloys

Abstract

Pure GaAs and GaAs1−xBix alloys with different Bi ratios (1 %, 2.5 %, 3.5 %) fitted with silver contacts were measured with a dielectric spectroscopy device. Dielectric characterization was performed at room temperature in the frequency range of 0.1 Hz to 1 MHz. GaAs exhibits three relaxation regions corresponding to space-charge, dipolar and ionic polarizations in sequence with increasing frequency while GaAs1−xBix samples show only a broad dipolar polarization in the same frequency range. This result proves the filling of the lattice with Bi through making a new bonding reducing the influence of ionic polarization. This finding supports the previous results concerning optical properties of GaAs1−xBix, presented in the literature.

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Size effect and dielectric properties of NH4H2PO4 — porous glass composites

Abstract

NH4H2PO4 nano-composite antiferroelectric materials in porous glass have been studied by means of dielectric and dilatometric investigations. Dielectric spectroscopy measurements in a wide frequency range are reported here for the first time, for both the antiferro- and paraelectric phases of ammonium dihydrogen phosphate (ADP) embedded in a porous matrix. Low frequency relaxation processes above the phase transition temperature were shown to occur. An investigation of the thermal expansion revealed a negative volume jump at the phase transition point. It was found that the phase transition temperature in ADP crystals embedded in porous glass decreased with the decrease of the mean pore size. The experimentally observed shift of the phase transition temperature is caused by a combination of size and pressure effects.

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Electrical Properties of Sunflower Achenes

.O. - GUO, W. - TRABELSI, S. - KAYS, S. J. 2007. Dielectric spectroscopy of watermelons for sensing quality. In Measurement Science and Technology, vol. 18, 2007, pp. 1887-1892. NELSON, S. O. 1991. Correlating dielectric properties of solid and particulate sample through mixture relationship. In Transactions of the ASAE, vol. 35, 1991, no. 2, pp. 625-629. NELSON, S.O. 1999. Dielectric properties measurement techniques and applications. In Transactions of the ASAE, vol. 42, 1999, no. 2, pp. 523-529. PRIATKOVA, L. - HLAVAČOVA

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Electrical Prope Rties of Popcorn Grains

. Correlating dielectric properties of solid and particulate sample through mixture relationship. In Transactions of the ASAE, vol. 35, no. 2, pp. 625-629. NELSON, S. O. 1999. Dielectric properties measurement techniques and applications. In Transactions of the ASAE, vol. 42, no. 2, pp. 523-529. NELSON, S. O. - GUO, W. - TRABELSI, S. - KAYS, S. J. 2007. Dielectric spectroscopy of watermelons for sensing quality. In Measurement Science and Technology, vol. 18, pp. 1887-1892. YOU, T. S. - NELSON, S. O. 1988. Microwave dielectric

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Electric Properties Measurement of Lentil

, S. – KAYS, S. J. 2007. Dielectric spectroscopy of watermelons for sensing quality. In Measurement Science and Technology, vol. 18, pp. 1887–1892. PRIATKOVÁ, L. – HLAVÁČOVÁ, Z. – KERTÉSZ, Á. 2011. Electrical capacity and resistance measurement of blueberry cultivars ( Vaccinium corymbosum L.). In Acta Technologica Agriculturae, vol. 14, no. 2, pp. 32–35. YOU, T. S. – NELSON, S. O. 1988. Microwave dielectric properties of rice kernels. In Microwave Power and Electromagnetic Energy, vol. 23, no. 3, pp. 150–159. WEIR, W. B. 1974. Automatic

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Screen printed and laminated electrodes for low-cost capacitive level measurement systems

Planar Interdigital Capacitor Level Sensor”, Przegląd Elektrotechniczny , vol. 1, no. 8, pp. 93–97, 2015. [7] N. Zoric, A. Iavorschi, M. Sireteanu, G. Viziteu and R. Ciobanu, “Design and Simulations of IDC Sensor Using COMSOL Multiphysics and Dielectric Spectroscopy of LTCC Materials”, Buletinul AGIR , vol. 3, pp. 63–69, 2013. [8] K. Loizou and E. Koutroulis, “Water Level Sensing: State of the Art Review and Performance Evaluation of a Low-Cost Measurement System”, Measurement , vol. 89, pp. 204–214, 2016. [9] K. Loizou, E. Koutroulis, D. Zalikas

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