Dielectric Relaxation of a Cholesterol Domain Near a Graphite Wall - A Computer Simulation

2008 ◽  
Vol 140 ◽  
pp. 153-158
Author(s):  
P. Raczynski ◽  
Z. Gburski
Keyword(s):  
Molecular Dynamics ◽  
Computer Simulation ◽  
Dipole Moment ◽  
Dielectric Loss ◽  
Dielectric Relaxation ◽  
Autocorrelation Function ◽  
Total Dipole Moment ◽  
Physiological Temperature ◽  
Pure Cholesterol

Molecular dynamics (MD) studies are presented for a cholesterol domain near a graphite wall. The dynamic observables of cholesterol at the physiological temperature of 309 K were investigated. Attention was focused on the total dipole moment → M autocorrelation function ( ) ( ) ( ) / (0)2 ∧ → → → C t = M t ⋅M t M and the dielectric loss spectrum ε’’(ν). Additionally, the comparison with the dielectric relaxation of a pure cholesterol cluster without a graphite wall is presented and discussed.

High Frequency Dielectric Response of the Ionic Liquid N-Methyl-N-ethylpyrrolidinium Dicyanamide

2007 ◽  
Vol 60 (1) ◽  
pp. 6 ◽  
Author(s):  
Simon Schrödle ◽  
Gary Annat ◽  
Douglas R. MacFarlane ◽  
Maria Forsyth ◽  
Richard Buchner ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Dielectric Loss ◽  
Dielectric Relaxation ◽  
High Frequency ◽  
Dielectric Response ◽  
Room Temperature ◽  
Room Temperature Ionic Liquid ◽  
Dielectric Relaxation Spectroscopy ◽  
Frequency Range ◽  
Fast Rotation

A study of the room-temperature ionic liquid N-methyl-N-ethylpyrrolidinium dicyanamide by dielectric relaxation spectroscopy over the frequency range 0.2 GHz ≤ ν ≤ 89 GHz has revealed that, in addition to the already known lower frequency processes, there is a broad featureless dielectric loss at higher frequencies. The latter is probably due to the translational (oscillatory) motions of the dipolar ions of the IL relative to each other, with additional contributions from their fast rotation.

Dielectric relaxation time and dipole moment of isometric butanols in benzene solutions.

1983 ◽  
Vol 26 (2) ◽  
pp. 77-84 ◽  
Author(s):  
S.M. Khameshara ◽  
M.S. Kavadia ◽  
M.S. Lodha ◽  
D.C. Mathur ◽  
V.K. Vaidya
Keyword(s):  
Dipole Moment ◽  
Relaxation Time ◽  
Dielectric Relaxation ◽  
Dielectric Relaxation Time

AC Loss Modeling in Ba0.5Sr0.5TiO3 Using Dielectric Relaxation

2004 ◽  
Vol 833 ◽  
Author(s):  
Nadia K. Pervez ◽  
Jiwei Lu ◽  
Susanne Stemmer ◽  
Robert A. York
Keyword(s):  
Dielectric Loss ◽  
Dielectric Relaxation ◽  
Power Law ◽  
Fractional Power ◽  
Ac Loss ◽  
Dielectric Susceptibility ◽  
Network Analyzer ◽  
Q Factor ◽  
Relaxation Model ◽  
Q Factors

ABSTRACTIn universal relaxation, a material's complex dielectric susceptibility follows a fractional power law f1-n where 0 < n < 1 over multiple decades of frequency. In a variety of materials, including Ba0.5Sr0.5Ti03, dielectric relaxation has been observed to follow this universal relaxation model with values of n close to 1. In this work we have shown that the universal relaxation model can be used to calculate dielectric loss even when n is very close to 1. Our calculated Q-factors agree with measured values at 1 MHz; this agreement suggests that this technique may be used for higher frequencies where network analyzer measurements and electrode parasitics complicate Q-factor determination.

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