Temperature dependence of vibrational relaxation processes in sulfur crystals: Effect of isotopic impurities

1992 ◽  
Vol 96 (1) ◽  
pp. 98-109 ◽  
Author(s):  
Maurizio Becucci ◽  
Emilio Castellucci ◽  
Paolo Foggi ◽  
Salvatore Califano ◽  
David A. Dows
Keyword(s):  
Temperature Dependence ◽  
Vibrational Relaxation ◽  
Relaxation Processes

Temperature Dependence of Dynamic Properties of Elastomers. Relaxation Distributions

1952 ◽  
Vol 25 (4) ◽  
pp. 720-729 ◽  
Author(s):  
John D. Ferry ◽  
Edwin R. Fitzgerald ◽  
Lester D. Grandine ◽  
Malcolm L. Williams
Keyword(s):  
Distribution Function ◽  
Temperature Dependence ◽  
Dynamic Properties ◽  
Relaxation Times ◽  
Dynamic Mechanical Properties ◽  
Relaxation Processes ◽  
The Real ◽  
Reduced Frequency ◽  
Dynamic Rigidity ◽  
Composite Curve

Abstract By the use of reduced variables, the temperature dependence and frequency dependence of dynamic mechanical properties of rubberlike materials can be interrelated without any arbitrary assumptions about the functional form of either The definitions of the reduced variables are based on some simple assumptions regarding the nature of relaxation processes. The real part of the reduced dynamic rigidity, plotted against the reduced frequency, gives a single composite curve for data over wide ranges of frequency and temperature; this is true also for the imaginary part of the rigidity or the dynamic viscosity. The real and imaginary parts of the rigidity, although independent measurements, are interrelated through the distribution function of relaxation times, and this relation provides a check on experimental results. First and second approximation methods of calculating the distribution function from dynamic data are given. The use of the distribution function to predict various types of time-dependent mechanical behavior is illustrated.

The pressure and temperature dependence of the relaxation processes in poly(methylmethacrylate)

Polymer ◽  
2001 ◽  
Vol 42 (1) ◽  
pp. 289-295 ◽  
Author(s):  
S. Theobald ◽  
W. Pechhold ◽  
B. Stoll
Keyword(s):  
Temperature Dependence ◽  
Relaxation Processes

scholarly journals The Dynamic Properties of 5Cb Filled with Aerosil Particles Investigated by Pcs

1999 ◽  
Vol 559 ◽  
Author(s):  
F.M. Aliev ◽  
M. Kreuzer ◽  
Yu.P. Panarin
Keyword(s):  
Liquid Crystal ◽  
Temperature Dependence ◽  
Relaxation Process ◽  
Nematic Liquid Crystal ◽  
Broad Spectrum ◽  
Dynamic Properties ◽  
Relaxation Times ◽  
Correlation Spectroscopy ◽  
Relaxation Processes ◽  
Optoelectronic Application

ABSTRACTNematic liquid crystal filled with Aerosil particles, a prospective composite material for optoelectronic application, has been investigated by static light scattering and Photon Correlation Spectroscopy (PCS). The Aerosil particles in filled nematic liquid crystals (FN) form a network structure with LC domains about 2500 Å in size with a random distribution of the director orientation of each domain.We found that the properties of 5CB are considerably affected by the network. The N-I phase transition in filled 5CB was found to be smeared out and depressed. PCS experiments show that two new relaxation processes appear in filled 5CB in addition to the director fluctuation process in bulk. The slow relaxation process, with a broad spectrum of relaxation times, is somewhat similar to the slow decay, which is observed in confined nematic liquid crystal.The middle frequency process was assigned to the director fluctuations in the surface layer formed at the particle-LC interface. The decay function describing this relaxation process is a stretched exponential (β ≍ 0.7). The temperature dependence of the relaxation times of the middle frequency obeys the Vogel-Rilcher law. Such a temperature dependence, accompanied by a broad spectrum of relaxation times suggests that the dynamics of the director fluctuations near the Aerosil particle-LC interface is glass-like.

A very rapid electronic relaxation process in a highly conjugated Zn(ii)porphyrin–[26]hexaphyrin–Zn(ii)porphyrin hybrid tape

2016 ◽  
Vol 18 (4) ◽  
pp. 3244-3249 ◽  
Author(s):  
Sangsu Lee ◽  
Hirotaka Mori ◽  
Taegon Lee ◽  
Manho Lim ◽  
Atsuhiro Osuka ◽  
...  
Keyword(s):  
Relaxation Process ◽  
Vibrational Relaxation ◽  
Energy Relaxation ◽  
Relaxation Processes ◽  
Electronic Relaxation ◽  
Vibronic State ◽  
Molecular Systems

We demonstrate that the electronic deactivation overtakes the vibrational relaxation processes in the energy relaxation processes from the initially excited vibronic state manifolds in highly conjugated molecular systems.

Sign in / Sign up

Export Citation Format

Share Document