Dynamic Mechanical Relaxation in Bulk Metallic Glasses: A Review

In this article, the frequency dependent dielectric properties, e(ω), of an “ideal” binary composite structure were investigated by using the finite element method in the frequency domain. The material properties of the phases, i.e., dielectric permittivity, e, and direct-current conductivity, σ, were assumed to be frequency independent. Moreover, the inclusion phase was more conductive than the matrix phase. The inclusions were infinitely long unidirectional cylinders which could be assumed to be hard disks in two dimensions in the direction perpendicular to the cylinder direction. Three different inclusion concentration levels were considered, e.g., low, intermediate, and high. The calculated dielectric relaxations were compared with those of the dielectric mixture formulas in the literature and it was found that there were no significant differences between the formulas and the numerical solutions at low inclusion concentration. Furthermore, the obtained responses were curve fitted by the addition of t...

Dielectric relaxation in dielectric mixtures: Application of the finite element method and its comparison with dielectric mixture formulas

The present article gives an overview of analytical and simulation approaches to describe the relaxation dynamics of proteins. Particularly emphasised are recent developments of theoretical models, such as fractional Brownian dynamics. The latter connects dynamical events seen on the pico- to nanoscond time scale, accessible to quasielastic neutron scattering, and functional dynamics of proteins on much longer time scales.

Quasielastic neutron scattering and relaxation processes in proteins: analytical and simulation-based models

Dielectric and magnetic properties of Nickel ferrite ceramics using crystalline powders derived from DL alanine fuel in sol–gel auto-combustion

https://publications.lib.chalmers.se/records/fulltext/local_129646.pdf

The protein glass transition as measured by dielectric spectroscopy and differential scanning calorimetry.

A general equation for the susceptibility of disordered systems is proposed. It is based on the experimental observation of power laws at frequencies far from the peak frequency of the imaginary part of the frequency dependent relaxation function, the susceptibility. The obtained general expression contains the equations of other proposed relaxation functions as special cases and, thus, it might be considered as a generalization of these. From this general equation we derive an equation specially adapted for the α relaxation in glass-forming materials. This equation contains only three fit parameters and it is thus very suitable for fitting real experimental data. It is shown that this equation is a good frequency domain representation of the time domain Kohlrausch–Williams–Watts stretched exponential. From the general equation we also derive a four-parameter “universal” equation that describes most types of responses and even inverted response data, i.e., response peaks more stretched on the low frequency side than on the (as is normal) high frequency side. The physical significance of the different parameters is qualitatively discussed and the proposed functions are shown to satisfactorily describe typical experimental data.

R. Bergman

Papers

General susceptibility functions for relaxations in disordered systems