Pressure and temperature dependences of the relaxation dynamics of cresolphthalein-dimethylether: Evidence of contributions from thermodynamics and molecular interactions

2001 ◽  
Vol 114 (24) ◽  
pp. 10872-10883 ◽  
Author(s):  
Marian Paluch ◽  
K. L. Ngai ◽  
Stella Hensel-Bielowka
Keyword(s):  
Molecular Interactions ◽  
Relaxation Dynamics ◽  
Temperature Dependences

Temperature dependences of intra- and inter-molecular interactions in water and 12-Crown-4 - a comparison

1990 ◽  
Vol 45 (1-2) ◽  
pp. 115-119
Author(s):  
V.R. Zhelyaskov ◽  
G.M. Georgiev ◽  
Zh.S. Nickolov ◽  
M.I. Miteva
Keyword(s):  
Molecular Interactions ◽  
Temperature Dependences

Anomalies of the Fast Relaxation Dynamics at Tg In Strong Glass Formers

1996 ◽  
Vol 455 ◽  
Author(s):  
A. Brodin ◽  
L. M. Torell
Keyword(s):  
Mode Coupling ◽  
Integral Intensity ◽  
Relaxation Dynamics ◽  
Quasielastic Scattering ◽  
Temperature Dependent ◽  
Heat Temperature ◽  
System A ◽  
Fast Relaxation ◽  
Temperature Dependences ◽  
Limiting Value

ABSTRACTStructural dynamics of two network forming glasses, B2O3 and GeO2, has been investigated by Raman scattering over a wide temperature range from ∼10 K to above the respective glass transition temperatures (Tg = 526 K for B2O3 and 800 K for GeO2). The spectra are analyzed in terms of two distinct contributions, related to vibrational and fast relaxational dynamics, respectively, and conventionally referred to as the boson peak (BP) and quasielastic scattering (QS). A quantity proportional to the fast relaxation strength may be deduced from the integral intensity of QS relative to BP of the spectra. It turns out, that for T < Tg the so-obtained QS intensity of the two glasses is similar and smoothly temperature dependent, and can qualitatively be described by e.g. the defect model or the soft potential model. As Tg is passed, there is a pronounced change in behavior and dramatic differences between the two systems are observed. Thus, the fast relaxational dynamics is obviously affected by Tg, a finding which is in contrast to the predictions of the mode coupling theory (MCT) of a single crossover temperature Tc > Tg. Moreover, the experimentally obtained value of the MCT exponent a, describing the shape of the fast dynamics, is by far exceeding the limiting value (a ≈ 0.395) of the theory, the deviation increasing with the strength of the system (a ≈ 0.7 for B2O3 and ≈ 0.9 for GeO2). The observed difference between the two glasses is discussed in terms of the fragility of the system manifested in jumps in the specific heat temperature dependences.

Rotary Beveling for In Situ Thin-Section Microscopy of Cell Cultures

1981 ◽  
Vol 39 ◽  
pp. 550-551
Author(s):  
Dean A. Handley ◽  
Jack T. Alexander ◽  
Shu Chien
Keyword(s):  
Cell Growth ◽  
Cell Cultures ◽  
Molecular Interactions ◽  
Convenient Method ◽  
Petri Dish ◽  
Simple Method ◽  
Thin Section Microscopy ◽  
Thin Sectioning ◽  
Organic Fluids

In situ preparation of cell cultures for ultrastructural investigations is a convenient method by which fixation, dehydration and embedment are carried out in the culture petri dish. The in situ method offers the advantage of preserving the native orientation of cell-cell interactions, junctional regions and overlapping configurations. In order to section after embedment, the petri dish is usually separated from the polymerized resin by either differential cryo-contraction or solvation in organic fluids. The remaining resin block must be re-embedded before sectioning. Although removal of the petri dish may not disrupt the native cellular geometry, it does sacrifice what is now recognized as an important characteristic of cell growth: cell-substratum molecular interactions. To preserve the topographic cell-substratum relationship, we developed a simple method of tapered rotary beveling to reduce the petri dish thickness to a dimension suitable for direct thin sectioning.

Relaxation dynamics in confined glasses

2000 ◽  
Vol 10 (PR7) ◽  
pp. Pr7-227-Pr7-232 ◽  
Author(s):  
B. Jérôme ◽  
E. Cecchetto ◽  
N. R. de Souza ◽  
A. L. Demirel
Keyword(s):  
Relaxation Dynamics

The Determination of the Magnetoelectric Coupling Coefficient in Ferroelectric–Ferromagnetic Composite Based on PZT–Ferrite

2013 ◽  
Vol 58 (4) ◽  
pp. 1401-1403 ◽  
Author(s):  
J.A. Bartkowska ◽  
R. Zachariasz ◽  
D. Bochenek ◽  
J. Ilczuk
Keyword(s):  
Dielectric Permittivity ◽  
Coupling Coefficient ◽  
Mean Field ◽  
Field Approximation ◽  
Theoretical Description ◽  
Magnetoelectric Coupling ◽  
Mean Field Approximation ◽  
Dielectric Measurements ◽  
Temperature Dependences ◽  
Multiferroic Composite

Abstract In the present work, the magnetoelectric coupling coefficient, from the temperature dependences of the dielectric permittivity for the multiferroic composite was determined. The research material was ferroelectric-ferromagnetic composite on the based PZT and ferrite. We investigated the temperature dependences of the dielectric permittivity (") for the different frequency of measurement’s field. From the dielectric measurements we determined the temperature of phase transition from ferroelectric to paraelectric phase. For the theoretical description of the temperature dependence of the dielectric constant, the Hamiltonian of Alcantara, Gehring and Janssen was used. To investigate the dielectric properties of the multiferroic composite this Hamiltonian was expressed under the mean-field approximation. Based on dielectric measurements and theoretical considerations, the values of the magnetoelectric coupling coefficient were specified.

Fluorescence of BODIPY Dyes in Gas Phase at near Ambient Conditions

2020 ◽  
Author(s):  
Kseniya A. Mariewskaya ◽  
Denis Larkin ◽  
Yuri Samoilichenko ◽  
Vladimir Korshun ◽  
Alex Ustinov
Keyword(s):  
Gas Phase ◽  
Molecular Interactions ◽  
Atmospheric Pressure ◽  
Fluorescence Spectra ◽  
Visible Range ◽  
Intrinsic Properties ◽  
Ambient Conditions ◽  
Ideal Model ◽  
Molecular Fluorescence ◽  
Tesla Coil

Molecular fluorescence is a phenomenon that is usually observed in condensed phase. It is strongly affected by molecular interactions. The study of fluorescence spectra in the gas phase can provide a nearly-ideal model for the evaluation of intrinsic properties of the fluorophores. Unfortunately, most conventional fluorophores are not volatile enough to allow study of their fluorescence in the gas phase. Here we report very bright gas phase fluorescence of simple BODIPY dyes that can be readily observed at atmospheric pressure using conventional fluorescence instrumentation. To our knowledge, this is the first example of visible range gas phase fluorescence at near ambient conditions. Evaporation of the dye in vacuum allowed us to demonstrate organic molecular electroluminescence in gas discharge excited by electric field produced by a Tesla coil.

Temperature Dependences of Photodissociation Cross Sections in Krypton Plasma

2020 ◽  
Vol 47 (10) ◽  
pp. 308-312
Author(s):  
K. S. Kislov ◽  
A. A. Narits ◽  
V. S. Lebedev
Keyword(s):  
Cross Sections ◽  
Temperature Dependences
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