% IMPORTANT: The following is UTF-8 encoded. This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.
@PHDTHESIS{Siboni:540077,
author = {Siboni, Nima H.},
othercontributors = {Varnik, Fathollah and Raabe, Dierk and Svendsen, Bob},
title = {{M}olecular dynamics studies of thermodynamical consistency
and non-locality of effective temperature},
school = {Aachen, Techn. Hochsch.},
type = {Dissertation},
address = {Aachen},
publisher = {Publikationsserver der RWTH Aachen University},
reportid = {RWTH-2015-05727},
year = {2016},
note = {Veröffentlicht auf dem Publikationsserver der RWTH Aachen
University 2016; Aachen, Techn. Hochsch., Diss., 2014},
abstract = {The issue of effective temperature for driven out of
equilibrium systems hasbeen the subject of a number of
theoretical and numerical studies. The effectivetemperature
reflects the fluctuations of the system at large time
scales, relevant for the slow structural relaxation. In
order to determine the time scale dependent temperature,
different thermometers with tunable time scale havebeen
introduced in the literature. In the present study, a
massive tracer particle, whose average kinetic energy
reflects the temperature associated with its momentum
fluctuations, is used as a thermometer. This particular
method is compared to the other proposed effective
temperature definitions and its deficiency in presence of
periodic boundary condition is studied. The reason for this
deficiency is discussed in detail and a modification to the
molecular dynamics algorithm is proposed to eliminate it. In
this study, it is also shown explicitly that this problem
does not occur at all in the presence of atomistically rough
solid walls, which is the case for all the non-equilibrium
simulations performed during this thesis. The walls
introduce spatial inhomogeneity in structural
relaxationwhich enables us to investigate two important
aspects of the effective temperature. On the one hand, the
walls lead to a non-uniform effective temperature profile,
which together with inhomogeneity in heat production due
todeformation, lay the ground to study its possible role for
heat conduction. Our investigations clearly show that heat
conduction is controlled by fast degrees of freedom only. In
particular, gradients in effective temperature play no role
for heat transfer. The flow inhomogeneity introduced by the
walls, on the other hand, provides a natural way to access
spatial correlations and cooperativity in the flow. In this
study, the issue of non-locality of the flow is addressed
via effective temperature, as the latter reflects
fluctuations relevant for the structural changes. A model
for predicting effective temperature is proposed, which
relates the effective temperature at a given point in space
to the plastic activity and correlations thereof in the
surrounding medium. By a comparison with a model which
neglects these correlations, the importance of non-local
effects is underlined.},
cin = {080003 / 523110 / 520000},
ddc = {550},
cid = {$I:(DE-82)080003_20140620$ / $I:(DE-82)523110_20140620$ /
$I:(DE-82)520000_20140620$},
typ = {PUB:(DE-HGF)11},
urn = {urn:nbn:de:hbz:82-rwth-2015-057277},
url = {https://publications.rwth-aachen.de/record/540077},
}
guest ::