Transport properties of a three-phase composite material: the square array of coated cylinders

1993 ◽  
Vol 442 (1916) ◽  
pp. 599-620 ◽  
Keyword(s):  
Dielectric Constant ◽  
Outer Radius ◽  
Periodic Array ◽  
Effective Dielectric Constant ◽  
The Core ◽  
Three Phase ◽  
The Matrix ◽  
Poles And Zeros ◽  
Special Points ◽  
Square Array

The analytic properties of the effective dielectric constant of a class of three-phase composite materials are studied. Specifically, we investigate the effective dielectric constant of a periodic array of coated cylinders, as a function of the core dielectric constant ( ϵ c ) and the shell dielectric constant ( ϵ s ), while keeping the matrix dielectric constant ( ϵ b ) fixed. We show that when ϵ s = – ϵ c , the composite has exactly the same effective dielectric constant as a periodic array of solid cylinders with dielectric constant ϵ c and radius equal to the outer radius of the original coated cylinder. We also show that when ϵ s = – 1, the composite has exactly the same effective dielectric constant as a periodic array of solid cylinders with dielectric constant ϵ c , and radius exceeding the shell radius. We explore the location of poles and zeros of the three-phase effective dielectric constant in the ( ϵ s , ϵ c ) plane. The lines ϵ s = – 1 and ϵ s + ϵ c = 0 are loci of essential singularities. We also comment on the behaviour of the effective dielectric constant in the neighbourhood of the two special points ( ϵ s , ϵ c ) = (0,0) and ( ϵ s , ϵ c ) = ( - 1 , + 1 ).

scholarly journals Characterization of percolation behavior in conductor–dielectric 0-3 composites

2014 ◽  
Vol 04 (04) ◽  
pp. 1450035 ◽  
Author(s):  
Lin Zhang ◽  
Patrick Bass ◽  
Zhi-Min Dang ◽  
Z.-Y. Cheng
Keyword(s):  
Dielectric Constant ◽  
Percolation Threshold ◽  
Frequency Dependence ◽  
Experimental Results ◽  
Effective Dielectric Constant ◽  
Filler Concentration ◽  
Percolation Behavior ◽  
The Matrix ◽  
The Relationship

The equation ε eff ∝ (ϕc - ϕ)-s which shows the relationship between effective dielectric constant (εeff) and the filler concentration (φ), is widely used to determine the percolation behavior and obtain parameters, such as percolation threshold φc and the power constant s in conductor–dielectric composites (CDCs). Six different systems of CDCs were used to check the expression by fitting experimental results. It is found that the equation can fit the experimental results at any frequency. However, it is found that the fitting constants do not reflect the real percolation behavior of the composites. It is found that the dielectric constant is strongly dependent on the frequency, which is mainly due to the fact that the frequency dependence of the dielectric constant for the composites close to φc is almost independent of the matrix.

An Analytical Model for the Effective Dielectric Constant of a 0-3-0 Composite

2010 ◽  
Author(s):  
K. A. Cook-Chennault ◽  
S. Banerjee
Keyword(s):  
Dielectric Constant ◽  
Aspect Ratio ◽  
Analytical Model ◽  
Experimental Results ◽  
Effective Dielectric Constant ◽  
The Third ◽  
Third Phase ◽  
Three Phase ◽  
Phase 0 ◽  
Experimental Values

An analytical expression for prediction of the effective dielectric constant of a three phase 0-3-0 ferroelectric composite is presented. The analytical results are verified with the experimental results from Nan et al [1]. We extend the analytical model, so that the influence of the shape of the third phase inclusion, on the effective dielectric constant of the composite, can be investigated. The results indicate that the dielectric constant increases ∼7 times, when the aspect ratio of the conductive inclusion is increased from 1 (sphere) to 10 (spheroid). The analytical predictions compare favorably with the experimental values.

THE RESONANT BEHAVIOR OF A MULTI-PHASE COMPOSITE MATERIAL

2002 ◽  
Vol 13 (03) ◽  
pp. 405-417
Author(s):  
ALI MOOSAVI ◽  
PERTTI SARKOMAA
Keyword(s):  
Finite Element Method ◽  
Dielectric Constant ◽  
Finite Element ◽  
Composite Material ◽  
Effective Dielectric Constant ◽  
The Finite Element Method ◽  
Resonant Behavior ◽  
Multi Phase ◽  
Square Array ◽  
Element Method

We study the resonant behavior of a system consisting of a square array of multi-coated cylinders by calculating the effective dielectric constant of the system. The results were examined numerically using the finite element method.

An Analytical Model for the Effective Dielectric Constant of a 0-3-0 Composite

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
S. Banerjee ◽  
K. A. Cook-Chennault
Keyword(s):  
Dielectric Constant ◽  
Aspect Ratio ◽  
Analytical Model ◽  
Effective Dielectric Constant ◽  
Inclusion Particle ◽  
Magnetoelectric Composite ◽  
Third Phase ◽  
Three Phase ◽  
Phase 0 ◽  
Experimental Values

An analytical expression for prediction of the effective dielectric constant of a three phase 0-3-0 ferroelectric composite is presented. The analytical results are verified with the experimental results from Nan et al. (2002, “Three-Phase Magnetoelectric Composite of Piezoelectric Ceramics, Rare-Earth Iron Alloys, and Polymer,” Appl. Phys. Lett., 81(20), p. 3831). The analytical model is extended to include the shape of a third phase inclusion to examine the influence of the shape (of the inclusion) on the effective dielectric constant of the composite. The dielectric constant increases as much as seven times when the aspect ratio of the conducting inclusion particle is increased from 1 (sphere) to 10 (spheroid). A comparison of the analytical predictions with the experimental values, which indicate that the increase in aspect ratio of the inclusions has a significant effect on the overall dielectric constant of the composite.

Multipolar Surface Plasmon Peaks in Gold Nanoshells

2015 ◽  
Vol 730 ◽  
pp. 137-140
Author(s):  
Xing Fang Zhang ◽  
Feng Shou Liu
Keyword(s):  
Dielectric Constant ◽  
Mie Theory ◽  
Outer Radius ◽  
Dielectric Constants ◽  
Gold Nanoshells ◽  
Core Size ◽  
Surface Charges ◽  
Conduction Electrons ◽  
The Core ◽  
Embedding Medium

The intensities of the dipole, quadrupole and octupole modes for gold nanoshells have been investigated with various dielectric constants for the embedding medium and with various sizes of the nanoshells by means of Mie theory. With the increase in the dielectric constant of embedding medium, it is found that the intensities of all modes become stronger first, and then the higher mode starts to become weak. We also observe with decreasing the core size of a nanoshell with a fixed outer radius, a larger dielectric constant for the embedding medium is needed corresponding to the change of higher mode intensities from stronger to weaker. We have ascribed the changes of the dipole, quadrupole and octupole modes to the competition among the variations of induced surface charges, conduction electrons and oscillation electrons.

The Structure and Development of Microbodies in the Fat Body and other Tissues of an Insect (Calpodes Ethlius)

1970 ◽  
Vol 28 ◽  
pp. 148-149
Author(s):  
M. Locke ◽  
J. T. McMahon
Keyword(s):  
Electron Microscopy ◽  
Liquid Crystals ◽  
Fat Body ◽  
Competitive Inhibitor ◽  
Dense Core ◽  
Urate Oxidase ◽  
Blood Proteins ◽  
Free Base ◽  
The Core ◽  
The Matrix

The fat body of insects has always been compared functionally to the liver of vertebrates. Both synthesize and store glycogen and lipid and are concerned with the formation of blood proteins. The comparison becomes even more apt with the discovery of microbodies and the localization of urate oxidase and catalase in insect fat body.The microbodies are oval to spherical bodies about 1μ across with a depression and dense core on one side. The core is made of coiled tubules together with dense material close to the depressed membrane. The tubules may appear loose or densely packed but always intertwined like liquid crystals, never straight as in solid crystals (Fig. 1). When fat body is reacted with diaminobenzidine free base and H2O2 at pH 9.0 to determine the distribution of catalase, electron microscopy shows the enzyme in the matrix of the microbodies (Fig. 2). The reaction is abolished by 3-amino-1, 2, 4-triazole, a competitive inhibitor of catalase. The fat body is the only tissue which consistantly reacts positively for urate oxidase. The reaction product is sharply localized in granules of about the same size and distribution as the microbodies. The reaction is inhibited by 2, 6, 8-trichloropurine, a competitive inhibitor of urate oxidase.

Measurement of effective dielectric constant : A comparison

2011 ◽  
Author(s):  
Aakashdeep ◽  
Saurav Kr. Basu ◽  
G. V. Ujjwal ◽  
Sakshi Kumari ◽  
V. R. Gupta
Keyword(s):  
Dielectric Constant ◽  
Effective Dielectric Constant

Contributions to Silicon-Hydrogen Bond-Stretching Frequency in Amorphous Si Alloys

1992 ◽  
Vol 258 ◽  
Author(s):  
Z. Jing ◽  
J. L. Whitten ◽  
G. Lucovsky
Keyword(s):  
Experimental Data ◽  
Hydrogen Bond ◽  
Dielectric Constant ◽  
Ab Initio ◽  
Effective Dielectric Constant ◽  
Bond Energies ◽  
Calculated Frequency ◽  
Bond Stretching ◽  
Amorphous Si ◽  
Good Agreement

ABSTRACTWe have performed ab initio calculations and determined the bond-energies and vibrational frequencies of Si-H groups that are: i) attached to Si-atoms as their immediate, and also more distant neighbors; and ii) attached to three O-atoms as their immediate neighbors, but are connected to an all Si-atom matrix. These arrangements simulate bonding geometries on Si surfaces, and the calculated frequency for i) is in good agreement with that of an Si-H group on an Si surface. To compare these results with a-Si:H alloys it is necessary to take into account an additional factor: the effective dielectric constant of the host. We show how to do this, demonstrating the way results of the ab initio calculations should then be compared with experimental data.

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