COMPLEX DIELECTRIC PERMITTIVITY IN ROCKS: A METHOD FOR ITS MEASUREMENT AND ANALYSIS

The interfacial effects arising in electrical measurements of rocks, when a two‐electrode system is used, are analyzed via the Maxwell‐Wagner effect. The similarity in electrical behavior between rock samples and heterogeneous dielectrics with nonnegligible ohmic conductivities leads to a general analysis of the Maxwell‐Wagner effect. We conclude that, in general, it is necessary to have volume charge accumulations at interfaces within the sample and at the electrode‐sample interface in order to have electrical steady‐state conditions in rock samples. The expression for the charge accumulation at the interface as a function of frequency is obtained as well as expressions for the effective dielectric permittivity in a composite material; the relaxation time associated with the charge accumulation and that of the effective dielectric permittivity are the same. Given a sample consisting of two different materials, it is shown that whenever both components have nonnegligible ohmic conductivities, the imaginary component of the effective dielectric permittivity tends to infinity when the frequency tends to zero; such behavior is not observed when one of the two conductivities is negligible. This fact constitutes the basis of the method of measurement for heterogeneous dielectrics with nonnegligible ohmic conductivities proposed herein. The method consists essentially of utilizing a dielectric with negligible ohmic and dielectric conductivities as one of the two components of the sample, which isolates the other one from the electrodes. Theoretical examples of the behavior of such a composite material for various cases are analyzed and three experimental examples are presented. The method presents the advantage of permitting application of theory developed for dielectrics in general.

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Ni-coated CaCu3Ti4O12/low density polyethylene composite material with ultra-high dielectric permittivity

AIP Advances ◽

10.1063/1.4930075 ◽

2015 ◽

Vol 5 (8) ◽

pp. 087183 ◽

Cited By ~ 8

Author(s):

L. Gao ◽

X. Wang ◽

Y. Chen ◽

Q. G. Chi ◽

Q. Q. Lei

Keyword(s):

Composite Material ◽

Dielectric Permittivity ◽

Low Density Polyethylene ◽

Low Density ◽

Polyethylene Composite ◽

High Dielectric Permittivity ◽

High Dielectric

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Measurement and Analysis of Triboelectric Surface Charge

Physics and High Technology ◽

10.3938/phit.30.002 ◽

2021 ◽

Vol 30 (1/2) ◽

pp. 7-11

Author(s):

Jinhong PARK ◽

Jinhyeok CHOI ◽

Sang Hyeok PARK ◽

Minbaek LEE

Keyword(s):

Electron Transfer ◽

Charge Transfer ◽

Surface Properties ◽

Elastic Moduli ◽

Surface Charges ◽

Contact Electrification ◽

Measurement And Analysis ◽

Different Types ◽

Triboelectric Charging ◽

Method Of Measurement

Contact electrification occurs when two isolated objects come into contact. Such a phenomenon led humans to first realization of the existence of electricity. Until now, the main causes of the triboelectric charging phenomenon have generally been thought to be the transfer of electrons, ions, and materials. This article, however, is limited to electron transfer on the surface, which is regarded as a general case not limited to specific situations. The contact between two objects occurs between the two surfaces; therefore, the surface properties of the material under examination are the most important properties in triboelectric charge transfer. The surface properties may include the types of materials in contact, their energy states, the roughnesses of their surfaces, and their elastic moduli. In this regard, we introduce here the current understanding of the energy band structures involved in the different types of materials, the method of measurement, an analysis of surface charges, and related applications.

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Optical bistability of planar metal/dielectric nonlinear nanostructures

Opto-Electronics Review ◽

10.2478/s11772-006-0029-6 ◽

2006 ◽

Vol 14 (3) ◽

Cited By ~ 15

Author(s):

R. Noskov ◽

A. Zharov

Keyword(s):

Dielectric Permittivity ◽

Field Intensity ◽

Optical Bistability ◽

Nonlinear Response ◽

Nanoscale Devices ◽

Nonlinear Dielectric ◽

Transmission Properties ◽

All Optical ◽

Effective Dielectric Permittivity

AbstractWe study theoretically a nonlinear response of the planar metal/dielectric nanostructures constituted from periodical array of ultra thin silver layers and the layers of Kerr-like nonlinear dielectric. We predict hysteresis-type dependences of the components of the tensor of effective dielectric permittivity on the field intensity allowing the change in material transmission properties from transparent to opaque and back at extremely low intensities of the light. It makes possible to control the light by light in all-optical nanoscale devices and circuits.

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Application of Multiphase Dielectric Mixing Models for Understanding the Effective Dielectric Permittivity of Frozen Soils

Vadose Zone Journal ◽

10.2136/vzj2012.0060 ◽

2013 ◽

Vol 12 (1) ◽

pp. vzj2012.0060 ◽

Cited By ~ 31

Author(s):

Hailong He ◽

Miles Dyck

Keyword(s):

Dielectric Permittivity ◽

Mixing Models ◽

Frozen Soils ◽

Effective Dielectric Permittivity

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Energy tunneling through narrow waveguide channel and design of small antennas

Serbian Journal of Electrical Engineering ◽

10.2298/sjee1101063m ◽

2011 ◽

Vol 8 (1) ◽

pp. 63-71

Author(s):

Miranda Mitrovic ◽

Branka Jokanovic

Keyword(s):

Wave Propagation ◽

Dielectric Permittivity ◽

Transmission Coefficient ◽

Rectangular Waveguide ◽

Narrow Channel ◽

Waveguide Channel ◽

Small Antennas ◽

Field Density ◽

Effective Dielectric Permittivity ◽

Small Antenna

In this paper we investigate the conditions for energy tunneling through narrow channel obtained by reducing the height of rectangular waveguide. Tunneling of the energy occurs at the frequency for which the effective dielectric permittivity of the channel becomes equal to zero, so it can be treated as an ENZ (epsilon-near-zero) metamaterial. We investigated how geometry of the channel and dielectric permittivity affect the transmission coefficient and field density in the channel. Adding slots in the channel, which are placed orthogonally to the wave propagation, we designed a small antenna with directivity of 5.44 dBi at the frequency of 3 GHz.

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Measurement and Analysis of Torque Ripple in Inverter Driven Electric Machines

INTER-NOISE and NOISE-CON Congress and Conference Proceedings ◽

10.3397/in-2021-1373 ◽

2021 ◽

Vol 263 (6) ◽

pp. 227-235

Author(s):

Mitchell Marks

Keyword(s):

Best Practices ◽

Torque Ripple ◽

Electric Machines ◽

Slow Speed ◽

Noise And Vibration ◽

Torque Response ◽

Measurement And Analysis ◽

Method Of Measurement ◽

Different Sources ◽

Speed Method

Torque ripple in electric machines can create both noise and vibration. While torque ripple is often well understood theoretically, it is much more difficult to accurately predict and measure. Often torque ripple is measured as a function of magnets and slot interaction at extremely low speed, but this can only be extrapolated to understand its implications for noise and vibration and is not useful for understanding torque response during dynamic scenarios like a change in load. The slow speed method of measurement also neglects possible switching effects on the torque profile. This paper will explore challenges in measuring the different sources of torque ripple and give an alternative method to measure torque ripple at higher speeds and also dynamically. This will include best practices and examples.

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Effective dielectric permittivity

Principles of Dielectric Logging Theory ◽

10.1016/b978-0-12-822283-6.00006-4 ◽

2020 ◽

pp. 219-256

Author(s):

Alex Kaufman ◽

Jean-Marc Donadille

Keyword(s):

Dielectric Permittivity ◽

Effective Dielectric Permittivity

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Evaluating Rank-Coherence of Crowd Rating in Customer Satisfaction

Social Indicators Research ◽

10.1007/s11205-020-02581-8 ◽

2020 ◽

Author(s):

Venera Tomaselli ◽

Giulio Giacomo Cantone

Keyword(s):

Customer Satisfaction ◽

Ad Hoc ◽

Data Gathering ◽

Social Contexts ◽

Public Utility ◽

Public Disclosure ◽

Measurement And Analysis ◽

Method Of Measurement ◽

Weighted Measure ◽

Rating Information

AbstractCrowd rating is a continuous and public process of data gathering that allows the display of general quantitative opinions on a topic from online anonymous networks as they are crowds. Online platforms leveraged these technologies to improve predictive tasks in marketing. However, we argue for a different employment of crowd rating as a tool of public utility to support social contexts suffering to adverse selection, like tourism. This aim needs to deal with issues in both method of measurement and analysis of data, and with common biases associated to public disclosure of rating information. We propose an evaluative method to investigate fairness of common measures of rating procedures with the peculiar perspective of assessing linearity of the ranked outcomes. This is tested on a longitudinal observational case of 7 years of customer satisfaction ratings, for a total amount of 26.888 reviews. According to the results obtained from the sampled dataset, analysed with the proposed evaluative method, there is a trade-off between loss of (potentially) biased information on ratings and fairness of the resulting rankings. However, computing an ad hoc unbiased ranking case, the ranking outcome through the time-weighted measure is not significantly different from the ad hoc unbiased case.

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