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Liste over projekter af typen: det fri projekt


Frit projekt, 3. modul, 2010, id:267
Vejleder:Kristine Niss
Findes på RUb:Ja
Abstract
English abstract
This project involves the introductionary work towards being able to test the hypothesis of existence of invariant isomorphs in strongly correlation viscous liquids. The principle in the experiment is to document the structural invarians along the isomorph using dielectric spectroscopy. Affiliated with this experiment is severel considerations, especially considering the time it takes to apply the change in temperature and pressure, compared to the time of relaxation of the liquid. We conclude that the time of relaxation should be of an order of magnitude ten times larger than the time it takes to perform the jump. Relevant predicted invariant isomorphs are localised, through a fit of measured data to the Vogel-Tammann-Fulcher and Avramov equations. Using these relevant points are determined for the specific experimental setup in the pressure-temperature phase diagram.


Frit projekt, 3. modul, 2009, id:263
Vejleder:
Findes på RUb:Ja
Abstract
English abstract
Dynamics and structure of a viscous liquid is studied through computer simulation in the NVT-ensemble. The simulated liquid is a binary Kob & Andersen mixture interacting through modified Lennard-Jones potentials. The modification is that only the repulsive part of the potential between AA and BB interactions are included whereas there is an attractive part in the AB interactions. The liquid is found to be strongly correlating for the majority of state points investigated. This means that the correlation coefficient between the equilibrium fluctuations in virial and potential energy is above 0.9. The liquid obeys density scaling to good approximation. This means that the characteristic time in reduced units of the systems only depends on the densityp p, and the temperature T, through (formel) where(formel) is a constant that can be determined form the equilibrium fluctuations in virial and potential energy. There is found evidence of the existence of isomorphic state points. These are state points with the same structure and dynamics in reduced units. It is found that the explanation of how to find these state points is incomplete. Two models explaining the non-Arrhenius behavior of viscous liquids are investigated. It is found that the shoving model is inconsistent with the result of the simulations whereas the Landscape equivalent of the shoving model can not be rejected.


Frit projekt, 3. modul, 2003, id:190
Vejleder:Tage Christensen
Findes på RUb:Ja
Abstract


Frit projekt, 3.. modul, 2000, id:169
Vejleder:Petr Viscor
Findes på RUb:ja
Abstract

Database opslag den: 15-12-2017