Journal ArticleDOI
Detailed comparison of the Williams–Watts and Cole–Davidson functions
C. P. Lindsey,G. D. Patterson +1 more
TLDR
In this paper, the distribution function of relaxation times underlying the nonexponential relaxation function of Williams and Watts is derived and compared with the analogous Cole-Davidson distribution function, and several useful relations between relaxation and distribution functions are summarized or derived, and the limitations of deriving distribution functions from relaxation functions are discussed.Abstract:
The distribution function of relaxation times underlying the nonexponential relaxation function of Williams and Watts is derived and compared with the analogous Cole–Davidson distribution function. In order to make the comparison between the two distribution functions, a simple empirical relationship between the Cole–Davidson and Williams–Watts parameters was determined which may be used to compare data analyzed using the two fitting functions. Although the relaxation functions are similar to each other, the distribution functions are quite dissimilar. The Cole–Davidson distribution shows a sharp long time cutoff, while the Williams–Watts distribution decays approximately exponentially at long times. Finally, several useful relations between relaxation and distribution functions are summarized or derived, and the limitations of deriving distribution functions from relaxation functions are discussed.read more
Citations
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Journal ArticleDOI
Influence of specific intermolecular interactions on the thermal and dielectric properties of bulk polymers: atomistic molecular dynamics simulations of Nylon 6
TL;DR: A reasonable agreement between the results of the simulations and experimental data for the density, thermal expansion coefficient, static dielectric constant and activation energy of γ and β relaxations is obtained demonstrating the validity of the modeling approach reported.
Journal ArticleDOI
Finite element modeling of transient ultrasonic waves in linear viscoelastic media
Paul Stucky,William Lord +1 more
TL;DR: An axisymmetric, displacement-based finite element method for modeling pulsed ultrasonic waves in linear, homogeneous, and isotropic viscoelastic media is developed that does not require storage of the complete time history of displacement at every node.
Journal ArticleDOI
Perspectives on Dye Sensitization of Nanocrystalline Mesoporous Thin Films.
TL;DR: Dye-sensitized conductive oxides also promote long-lived charge separation with bias dependent kinetics that provide insights into the reorganization energies associated with electron and proton-coupled electron transfer in the electric double layer.
Journal ArticleDOI
Physical ageing studies of polysiloxane-modified epoxy resin
TL;DR: In this article, the physical ageing phenomena of epoxy network systems were studied by differential scanning calorimetry, showing that internal stress relaxation and enthalpy relaxation take place simultaneously during annealing.
Journal ArticleDOI
Photoluminescence of hydrophilic silicon nanocrystals in aqueous solutions.
N. Prtljaga,Elvira D’Amato,Alessandro Pitanti,Alessandro Pitanti,Romain Guider,E. Froner,S. Larcheri,Marina Scarpa,Lorenzo Pavesi +8 more
TL;DR: The time evolution of the photoluminescence properties of these hydrophilic silicon nanocrystals has been followed and these properties render Si-nc very useful as a labeling agent for biosensing.
References
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Journal ArticleDOI
Dispersion and Absorption in Dielectrics I. Alternating Current Characteristics
Kenneth S. Cole,Robert H. Cole +1 more
TL;DR: In this paper, the locus of the dielectric constant in the complex plane was defined to be a circular arc with end points on the axis of reals and center below this axis.
Journal ArticleDOI
Non-symmetrical dielectric relaxation behaviour arising from a simple empirical decay function
Graham Williams,David C. Watts +1 more
TL;DR: In this article, the empirical dielectric decay function γ(t)= exp −(t/τ 0)β was transformed analytically to give the frequency dependent complex dielectrics constant if β is chosen to be 0.50 in the range log(ωτ0) > −0.5.
Journal ArticleDOI
Analysis of Structural Relaxation in Glass Using Rate Heating Data
TL;DR: In this paper, a method was developed to determine the kinetic parameters controlling structural relaxation in the glass transition region from data acquired during continuous heating or cooling, where the data were linearized using the method of Narayanaswamy, and the continuous temperature variation during heating and cooling was dealt with by invoking the superposition principle.
Journal ArticleDOI
Further considerations of non symmetrical dielectric relaxation behaviour arising from a simple empirical decay function
TL;DR: The empirical dielectric decay function ϕ(t)= exp −(t/τ0)β, 0 0, but significant corrections may have to be applied for β > 0.5 and log ωτ0 < 0.
Journal ArticleDOI
On the numerical inversion of the Laplace transform and similar Fredholm integral equations of the first kind
J G McWhirter,E R Pike +1 more
TL;DR: In this article, the Laplace transform and other dilationally invariant integral equations of the first kind were derived for the eigenfunctions and eigenvalues, and the maximum possible amount of information was obtained when solving the inverse problem numerically.
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