Temperature and pressure dependence of self-diffusion, viscosity and nuclear relaxation times in liquid water

1973 ◽  
Vol 23 (1) ◽  
pp. 69-72 ◽  
Author(s):  
D.E. O'Reilly ◽  
E.M. Peterson ◽  
C.E. Scheie
Keyword(s):  
Pressure Dependence ◽  
Liquid Water ◽  
Relaxation Times ◽  
Nuclear Relaxation ◽  
Self Diffusion ◽  
Temperature And Pressure

scholarly journals Effect of Temperature and Pressure on Segmental Relaxation in Polymethylphenylsiloxane

2003 ◽  
Vol 76 (5) ◽  
pp. 1106-1115 ◽  
Author(s):  
S. Pawlus ◽  
S. J. Rzoska ◽  
J. Ziolo ◽  
M. Paluch ◽  
C. M. Roland
Keyword(s):  
Molecular Weight ◽  
Glass Transition ◽  
Pressure Dependence ◽  
Activation Volume ◽  
Relaxation Times ◽  
Effect Of Temperature ◽  
Loss Peak ◽  
Glass Transition Temperatures ◽  
Segmental Relaxation ◽  
Temperature And Pressure

Abstract Segmental relaxation in a series of polymethylphenylsiloxanes (PMPS) was studied using dielectric spectroscopy. The measurements covered a temperature range of more than 40 deg at pressures from ambient to 115 MPa. The results confirmed that the shape of the loss peak is independent of temperature, pressure and molecular weight. Consequently, the Tg -scaled dependence of the relaxation times was also independent of molecular weight. The pressure dependence of the relaxation times was characterized by means of the activation volume. This quantity changes markedly with pressure at a given temperature. However, the activation volume at the respective glass transition temperatures of the PMPS are essentially invariant to molecular weight. Finally, we measured the dependence of Tg on pressure, with the results well-described by the Andersson equation.

Temperature and pressure dependence of self diffusion in nonassociating liquids

1992 ◽  
Vol 54 (4) ◽  
pp. vii-ix ◽  
Author(s):  
F. Bachl ◽  
T. Vardag ◽  
S. Wappmann ◽  
H.-D. Lüdemann
Keyword(s):  
Pressure Dependence ◽  
Self Diffusion ◽  
Temperature And Pressure

Cu NQR Studies of the Superconductors YBa2Cu3Ox and YBa2Cu4O8

1990 ◽  
Vol 45 (3-4) ◽  
pp. 393-400 ◽  
Author(s):  
D. Brinkmann
Keyword(s):  
Pressure Dependence ◽  
Oxygen Deficiency ◽  
Relaxation Times ◽  
Electric Field Gradients ◽  
Field Gradients ◽  
Temperature And Pressure ◽  
University Of Zurich ◽  
The University ◽  
Knight Shifts

Abstract The paper reviews some copper NQR studies in the superconductors YBa2Cu3Ox and YBa2Cu4O8 performed at the University of Zürich. The following topics are discussed: the temperature and pressure dependence of the NQR frequencies; relation between linewidths and oxygen deficiency; the determination of the electric field gradients (EFG) and Knight shifts at the copper sites; discussion of some calculations of the EFG tensors; measurements of the various relaxation times in all phases. The results obtained in both structures are compared; possible interpretations are discussed.

Temperature and Pressure Dependence of Self Diffusion in Octamethylcyclotetrasiloxane and Hexamethylcyclotrisilazane

1990 ◽  
Vol 45 (11-12) ◽  
pp. 1281-1284 ◽  
Author(s):  
A. Greiner-Schmid ◽  
M. Has ◽  
H.-D. Lüdemann
Keyword(s):  
Magnetic Field ◽  
Pressure Dependence ◽  
Spin Echo ◽  
The Self ◽  
Self Diffusion ◽  
Field Gradients ◽  
Magnetic Field Gradients ◽  
Temperature And Pressure ◽  
Spin Echo Technique ◽  
Self Diffusion Coefficient

AbstractThe pressure dependence of the self diffusion coefficient D for octamethylcyclotetrasiloxane and hexamethylcyclotrisilazane has been determined by the NMR spin echo technique with pulsed magnetic field gradients at pressures up to 200 MPa and at temperatures between 490 K and 290 K. The data extend partially into the deeply supercooled range. The isobaric temperature dependence of these data is quantitatively described by the empirical Vogel-Fulcher-Tammann equation. For both substances the melting pressure curves were determined in addition.

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