Kinetics of structural relaxations in a two-dimensional model atomic glass III

1989 ◽  
Vol 329 (1608) ◽  
pp. 595-612 ◽  
Keyword(s):  
Molecular Dynamics ◽  
Free Energy ◽  
Excess Enthalpy ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Distortion Parameter ◽  
Topological Features ◽  
Two Dimensional Model ◽  
Molecular Dynamics Methods ◽  
Kinetics Of

The kinetics of structural relaxation in a two-dimensional model atomic glass quenched infinitely rapidly from the melt to 0.55 of the glass transition tem perature was simulated by the molecular dynamics methods to study the chronological ordering of the atomic kinematics associated with such relaxations. Over the very short periods of ageing ( ca .200 atomic fluctuations) accessible to the molecular dynamics (MD) method, a Williams-Watts form of relaxation with a fractional exponent of 0.5 was found to hold for excess enthalpy, free volume and site distortion parameter. The distribution of free energy barriers associated with the relaxation that resulted from the analysis could be scaled up to describe processes occurring on macroscopic timescales, and agrees well with experimental results in Cu x Zr 1-x glasses. Results on the clustering of relaxations and other topological features of the relaxation process are also reported.

Topological features of structural relaxations in a two-dimensional model atomic glass II

1989 ◽  
Vol 329 (1608) ◽  
pp. 575-593 ◽  
Keyword(s):  
Molecular Dynamics ◽  
Dynamics Simulation ◽  
Two Dimensional ◽  
Structure And Properties ◽  
High Angle ◽  
Stable Sets ◽  
Dimensional Model ◽  
Topological Features ◽  
Atom Clusters ◽  
Two Dimensional Model

The topological features of atom motions in a high-temperature melt, a sub-cooled melt above T g , and a glass below T g , were analysed in detail by means of a two-dimensional molecular dynamics simulation. A striking analogy was observed between the structure and properties of the liquid-like material separating quasi-ordered domains of atom clusters, and high-angle grain boundaries. The main feature of the structural relaxation below the melting point, both above and below T g was the gradual dissolution and disappearance of the liquid-like material, permitting increasing order in the previously quasi-ordered domains and a growth in their sizes. In these processes, many sequences reminiscent of cancellation of dislocation pairs, or mutual reactions to give more stable sets, were observed.

Molecular dynamics study of a two-dimensional model of squaric acid

1979 ◽  
Vol 40 (6) ◽  
pp. 463-467 ◽  
Author(s):  
D. Pumpernik ◽  
I. Mendaš ◽  
B. Borštoik ◽  
A. Ažman
Keyword(s):  
Molecular Dynamics ◽  
Squaric Acid ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Two Dimensional Model

scholarly journals Molecular dynamics simulation of the effect of dislocations on the martensitic transformations in a two-dimensional model

2017 ◽  
Vol 7 (4) ◽  
pp. 442-446 ◽  
Author(s):  
S. V. Dmitriev ◽  
M. P. Kashchenko ◽  
J. A. Baimova ◽  
R. I. Babicheva ◽  
D. V. Gunderov ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Martensitic Transformations ◽  
Dynamics Simulation ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Two Dimensional Model

scholarly journals Comparison of diffusion models for description of osmotic dehydration of radish slices dipped in brine

2015 ◽  
Vol 35 (5) ◽  
pp. 894-904
Author(s):  
Wilton P. da Silva ◽  
Cleide M. D. P. da S. E Silva ◽  
Josivanda P. Gomes
Keyword(s):  
Experimental Data ◽  
Boundary Condition ◽  
Low Temperature ◽  
Osmotic Dehydration ◽  
Two Dimensional ◽  
Dimensional Model ◽  
The Third ◽  
Two Dimensional Model ◽  
Mass Transfers ◽  
Kinetics Of

ABSTRACT This paper aims at describing the osmotic dehydration of radish cut into cylindrical pieces, using one- and two-dimensional analytical solutions of diffusion equation with boundary conditions of the first and third kind. These solutions were coupled with an optimizer to determine the process parameters, using experimental data. Three models were proposed to describe the osmotic dehydration of radish slices in brine at low temperature. The two-dimensional model with boundary condition of the third kind well described the kinetics of mass transfers, and it enabled prediction of moisture and solid distributions at any given time.

Commitment to pro- versus counter-attitudinal behavior and the dynamics of social representations

2002 ◽  
Vol 61 (1) ◽  
pp. 34-44 ◽  
Author(s):  
Eric Tafani ◽  
Lionel Souchet
Keyword(s):  
Higher Education ◽  
Social Representations ◽  
Cognitive Restructuring ◽  
Social Representation ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Social Actions ◽  
The Social ◽  
Two Dimensional Model ◽  
Students Attitudes

This research uses the counter-attitudinal essay paradigm ( Janis & King, 1954 ) to test the effects of social actions on social representations. Thus, students wrote either a pro- or a counter-attitudinal essay on Higher Education. Three forms of counter-attitudinal essays were manipulated countering respectively a) students’ attitudes towards higher education; b) peripheral beliefs or c) central beliefs associated with this representation object. After writing the essay, students expressed their attitudes towards higher education and evaluated different beliefs associated with it. The structural status of these beliefs was also assessed by a “calling into question” test ( Flament, 1994a ). Results show that behavior challenging either an attitude or peripheral beliefs induces a rationalization process, giving rise to minor modifications of the representational field. These modifications are only on the social evaluative dimension of the social representation. On the other hand, when the behavior challenges central beliefs, the same rationalization process induces a cognitive restructuring of the representational field, i.e., a structural change in the representation. These results and their implications for the experimental study of representational dynamics are discussed with regard to the two-dimensional model of social representations ( Moliner, 1994 ) and rationalization theory ( Beauvois & Joule, 1996 ).

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