On the dispersion of the dielectric constant of an inhomogeneous dielectric

1969 ◽  
Vol 9 (3) ◽  
pp. 25-28
Author(s):  
Yu. D. Pankov
Keyword(s):  
Dielectric Constant ◽  
Inhomogeneous Dielectric

SCATTERING FROM A CYLINDER COATED WITH AN INHOMOGENEOUS DIELECTRIC SHEATH

1963 ◽  
Vol 41 (1) ◽  
pp. 143-151 ◽  
Author(s):  
C. Yeh ◽  
Z. A. Kaprielian
Keyword(s):  
Dielectric Constant ◽  
Scattering Problem ◽  
Plane Waves ◽  
Space Vehicle ◽  
Plasma Sheath ◽  
Scattering Coefficients ◽  
Average Value ◽  
Inhomogeneous Dielectric ◽  
Specific Variation ◽  
Plane Wave Scattering

As a space vehicle re-enters the atmosphere, a plasma sheath, surrounding the vehicle, is generated. It is well known that the sheath is inhomogeneous. However, to make this problem suitable for theoretical analysis, most investigators make the assumption that the sheath is homogeneous. To investigate the validity of this assumption, the idealized problem of the scattering of plane waves by a conducting cylinder coated with a stratified dielectric sheath is considered. The wave equation is separated using the vector wave-function method of Hansen and Stratton. It is then applied to the plane-wave scattering problem. The backscattering cross section is defined and obtained. Analytical expressions for the scattering coefficients of a thin inhomogeneous sheath are also given. Numerical computations are carried out for a specific variation of the dielectric sheath: i.e., ε(r) = ε0α/k0r, where α is a constant, k02 = ε2 με0, and ε0 is the free-space dielectric constant. Results are compared with the homogeneous sheath problem; the dielectric constant of the homogeneous sheath is taken to be the average value of that for the inhomogeneous sheath. It is found that in general rather distinct differences are observed except when the sheath is very thin.

An improved quantum biochemistry description of the glutamate–GluA2 receptor binding within an inhomogeneous dielectric function framework

2017 ◽  
Vol 41 (14) ◽  
pp. 6167-6179 ◽  
Author(s):  
A. C. V. Martins ◽  
P. de-Lima-Neto ◽  
E. W. S. Caetano ◽  
V. N. Freire
Keyword(s):  
Dielectric Constant ◽  
Dielectric Function ◽  
Receptor Binding ◽  
Electrostatic Interaction ◽  
Protein Residues ◽  
Inhomogeneous Dielectric

A new methodology to define the inhomogeneous dielectric constant of protein residues, to apply to the calculation of protein–ligand properties such as the electrostatic interaction.

scholarly journals On the modeling of polar component of solvation energy using smooth Gaussian-based dielectric function

2014 ◽  
Vol 13 (03) ◽  
pp. 1440002 ◽  
Author(s):  
Lin Li ◽  
Chuan Li ◽  
Emil Alexov
Keyword(s):  
Dielectric Constant ◽  
Dielectric Function ◽  
Solvation Energy ◽  
Bulk Water ◽  
Dielectric Medium ◽  
Water Phase ◽  
Polar Component ◽  
Implicit Methods ◽  
Inhomogeneous Dielectric ◽  
Polar Solvation

Traditional implicit methods for modeling electrostatics in biomolecules use a two-dielectric approach: a biomolecule is assigned low dielectric constant while the water phase is considered as a high dielectric constant medium. However, such an approach treats the biomolecule–water interface as a sharp dielectric border between two homogeneous dielectric media and does not account for inhomogeneous dielectric properties of the macromolecule as well. Recently we reported a new development, a smooth Gaussian-based dielectric function which treats the entire system, the solute and the water phase, as inhomogeneous dielectric medium (Li L, Li C, Zhang Z, Alexor E, On the dielectric constant of proteins: Smooth dielectric function for macromolecular modeling and its implementation in Delphi, J Chem Theory Comput9(4):2126–2136, 2013). Here we examine various aspects of the modeling of polar solvation energy in such inhomogeneous systems in terms of the solute–water boundary and the inhomogeneity of the solute in the absence of water surrounding. The smooth Gaussian-based dielectric function is implemented in the DelPhi finite-difference program, and therefore the sensitivity of the results with respect to the grid parameters is investigated, and it is shown that the calculated polar solvation energy is almost grid independent. Furthermore, the results are compared with the standard two-media model and it is demonstrated that on average, the standard method overestimates the magnitude of the polar solvation energy by a factor 2.5. Lastly, the possibility of the solute to have local dielectric constant larger than of a bulk water is investigated in a benchmarking test against experimentally determined set of pKa's and it is speculated that side chain rearrangements could result in local dielectric constant larger than 80.

Microstructural characterization of YBaCuO Films on LaAlO3 substrates

1989 ◽  
Vol 47 ◽  
pp. 180-181
Author(s):  
E. L. Hall ◽  
A. Mogro-Campero ◽  
N. Lewis ◽  
L. G. Turner
Keyword(s):  
Dielectric Constant ◽  
Single Crystal ◽  
Film Growth ◽  
Microstructural Characterization ◽  
Lattice Parameter ◽  
Film Plane ◽  
Substrate Material ◽  
High Loss ◽  
Amorphous Substrates ◽  
High Dielectric

There have been a large number of recent studies of the growth of Y-Ba-Cu-O thin films, and these studies have employed a variety of substrates and growth techniques. To date, the highest values of Tc and Jc have been found for films grown by sputtering or coevaporation on single-crystal SrTiO3 substrates, which produces a uniaxially-aligned film with the YBa2Cu3Ox c-axis normal to the film plane. Multilayer growth of films on the same substrate produces a triaxially-aligned film (regions of the film have their c-axis parallel to each of the three substrate <100> directions) with lower values of Jc. Growth of films on a variety of other polycrystalline or amorphous substrates produces randomly-oriented polycrystalline films with low Jc. Although single-crystal SrTiO3 thus produces the best results, this substrate material has a number of undesireable characteristics relative to electronic applications, including very high dielectric constant and a high loss tangent at microwave frequencies. Recently, Simon et al. have shown that LaAlO3 could be used as a substrate for YBaCuO film growth. This substrate is essentially a cubic perovskite with a lattice parameter of 0.3792nm (it has a slight rhombohedral distortion at room temperature) and this material exhibits much lower dielectric constant and microwave loss tangents than SrTiO3. It is also interesting from a film growth standpoint since it has a slightly smaller lattice parameter than YBa2Cu3Ox (a=0.382nm, b=c/3=0.389nm), while SrTiO3 is slightly larger (a=0.3905nm).

Enhanced performance of supercapacitors by constructing a “mini parallel-plate capacitor” in an electrode with high dielectric constant materials

2020 ◽  
Vol 8 (32) ◽  
pp. 16661-16668
Author(s):  
Huayao Tu ◽  
Shouzhi Wang ◽  
Hehe Jiang ◽  
Zhenyan Liang ◽  
Dong Shi ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Carbon Fiber ◽  
Parallel Plate ◽  
Sandwich Structure ◽  
High Dielectric Constant ◽  
Parallel Plate Capacitor ◽  
Plate Capacitor ◽  
Fiber Metal ◽  
High Dielectric ◽  
Mini Plate

The carbon fiber/metal oxide/metal oxynitride layer sandwich structure is constructed in the electrode to form a mini-plate capacitor. High dielectric constant metal oxides act as dielectric to increase their capacitance.

Ultrahigh Energy Storage Performances of Polymer-based Nanocomposite via Interfaces Engneering

2020 ◽  
Author(s):  
Peng Wang ◽  
Zhongbin Pan ◽  
Weilin Wang ◽  
Jianxu Hu ◽  
Jinjun Liu ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Energy Storage ◽  
High Performance ◽  
Breakdown Strength ◽  
Composite Films ◽  
Power Electronic ◽  
Ultrahigh Energy

High-performance electrostatic capacitors are in urgent demand owing to the rapidly development of advanced power electronic applications. However, polymer-based composite films with both high breakdown strength (Eb) and dielectric constant...

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