A study on the short time dynamical behavior of Hamiltonian systems and its relationship to non-equilibrium statistical properties

1989 ◽  
Vol 39 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Antonis D Mistriotis
Keyword(s):  
Hamiltonian Systems ◽  
Dynamical Behavior ◽  
Statistical Properties ◽  
Short Time ◽  
Non Equilibrium

scholarly journals Thermal processes in molecular gas

1991 ◽  
Vol 147 ◽  
pp. 197-204
Author(s):  
J.P. Chièze ◽  
C. de Boisanger
Keyword(s):  
Ultraviolet Radiation ◽  
Molecular Clouds ◽  
Radiation Flux ◽  
Molecular Gas ◽  
Heating And Cooling ◽  
Collective Motions ◽  
Thermochemical Processes ◽  
Order Of Magnitude ◽  
Short Time ◽  
Non Equilibrium

The dynamics of the cold atomic and molecular gas, on which we focus here, is strongly affected by non equilibrium heating and cooling processes. We give two different examples, in which the breaking of the thermal balance is due respectively to variations of the incident ultraviolet radiation flux, and non equilibrium abundances of H2 molecules in molecular clouds envelopes. Fluctuations of the ultraviolet radiation flux in clumpy molecular cloud envelopes result in the formation or the destruction of dense regions. Large density contrasts, greater than one order of magnitude, are easily achieved in cloud regions of moderate visual extinction. Condensation or expansion develop on quite short time scales, of the order of a few tenth of million year, and induce collective motions which can feed turbulence.Another example of the importance of out of equilibrium thermochemical processes is furnished by the study of the H — H2 transition layers in molecular clouds envelopes. They turn out to be unstable against convection-like motions, driven by the energy released by H2 photodestruction. The gas velocities involved in these motions are, again, typical of the observed turbulent velocity in clouds envelopes.

scholarly journals Non-equilibrium critical behavior of Heisenberg thin films

2018 ◽  
Vol 185 ◽  
pp. 11005
Author(s):  
Maria A. Shlyakhtich ◽  
Pavel V. Prudnikov
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Critical Exponents ◽  
Dynamic Method ◽  
Critical Temperatures ◽  
Time Dynamic ◽  
Ferromagnetic Films ◽  
Time Scaling ◽  
Short Time ◽  
Non Equilibrium

In this work we study the non-equilibrium properties of Heisenberg ferromagnetic films using Monte Carlo simulations by short-time dynamic method. By exploring the short-time scaling dynamics, we have found thickness dependency of critical exponents z, θ′ and β/v for ferromagnetic thin film. For calculating the critical exponents of ferromagnetic films we considered systems with linear size L = 128 and layers number N = 2; 4; 6; 10. Starting from initial configurations, the system was updated with Metropolis algorithm at the critical temperatures

As-Quenched ARC Products By bulse - Discharge

2000 ◽  
Vol 6 (S2) ◽  
pp. 54-55
Author(s):  
Y. Murooka ◽  
Y. Maede ◽  
M. Ozaki ◽  
M. Hibino
Keyword(s):  
Steady State ◽  
Arc Discharge ◽  
Electron Bombardment ◽  
Discharge Process ◽  
Arc Plasma ◽  
Growth Mechanisms ◽  
Physical Processes ◽  
Small Current ◽  
Short Time ◽  
Non Equilibrium

Since their discovery, steady state arc discharge has been used for fullerenes and nanotubes production. Unfortunately this method intrinsically made it difficult to understand their growth mechanisms since the discharge included many complicated physical processes and the growth happened in the non-equilibrium arc plasma. Processes such as heating of the cathode by cation bombardment, emission of thermal electrons, and heating of the anode by electron bombardment are important in order to follow the mechanism, but it is difficult to study them separately. In the present work, however, it was shown that a pulse-arc discharge with a small current for a short time could simplify the discharge process and provide as-quenched arc products, which should be useful to understand the mechanisms.Short discharges with a small current were performed on the pulse-arc system, which was developed by the authors.

Non-Equilibrium Critical Dynamics of Ferromagnets with Long Range Correlated Defects

2012 ◽  
Vol 190 ◽  
pp. 31-34
Author(s):  
Dmitry N. Kulikov ◽  
Pavel V. Prudnikov
Keyword(s):  
Critical Exponent ◽  
Long Range ◽  
Critical Behavior ◽  
Disordered Systems ◽  
Asymptotic Series ◽  
Three Dimensional ◽  
Time Regime ◽  
Short Time ◽  
Short Time Evolution ◽  
Non Equilibrium

The simultaneous effect of non-equilibrium initial states and correlation betweendefects of the structure on the evolution of anisotropic disordered systems at the critical pointwas analyzed. The field theory description of the non-equilibrium critical behavior of three-dimensional disordered systems with the long-range correlated defects was given and the dy-namical critical exponent of the short-time evolution was calculated in the two-loop approxima-tion without the use of the "-expansion. The values of the dynamical critical exponent obtainedby using various methods for summing asymptotic series were compared with the results ofthe computer simulation of the non-equilibrium critical behavior of the three-dimensional dis-ordered Ising model in the short-time regime.

Crack Position and Depth Identification in Rotating Shafts: Part 2 — Experimental Results

2005 ◽  
Author(s):  
Nicolo` Bachschmid ◽  
Paolo Pennacchi ◽  
Ezio Tanzi
Keyword(s):  
Dynamical Behavior ◽  
Industrial Applications ◽  
Experimental Results ◽  
Crack Identification ◽  
Identification Method ◽  
Different Types ◽  
Rotating Shafts ◽  
Short Time ◽  
Crack Position ◽  
Deep Crack

This paper presents the experimental validation of a model based transverse crack identification method suitable for industrial machines, described in part 1. The method is validated by experimental results obtained on two test rigs, which were expressly designed for investigating the dynamical behavior of cracked horizontal rotors. On the first test rig, only one crack type is considered, while on the second one three different types of crack have been analyzed: the first is a slot, therefore not actually a crack since it has not the typical breathing behavior, the second a small crack (14% of the diameter) and the third a deep crack (47% of the diameter). The excellent accuracy obtained in identifying position and depth of different cracks proves the effectiveness and reliability of the proposed method. Moreover, the implementation of identification method operates on a PC and takes short time to run, therefore is suitable for industrial applications.

Study of phase transitions from short-time non-equilibrium behaviour

2011 ◽  
Vol 74 (2) ◽  
pp. 026501 ◽  
Author(s):  
E V Albano ◽  
M A Bab ◽  
G Baglietto ◽  
R A Borzi ◽  
T S Grigera ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Short Time ◽  
Non Equilibrium

Entropy, fluctuation and transport in lattice gas systems with generalized semi-detailed balance

1997 ◽  
Vol 57 (1) ◽  
pp. 175-185 ◽  
Author(s):  
HUDONG CHEN
Keyword(s):  
Lattice Gas ◽  
Detailed Balance ◽  
Statistical Properties ◽  
Continuous Systems ◽  
Physical Processes ◽  
Detailed Balance Condition ◽  
Balance Condition ◽  
Dirac Type ◽  
Reciprocity Relations ◽  
Non Equilibrium

We describe the existence of an entropy for lattice gas systems of Fermi–Dirac type based on a generalized semi-detailed balance condition. We demonstrate some essential equilibrium and non-equilibrium fluctuation and dissipation properties, including the so-called Onsager's reciprocity relations, as a consequence of this condition. Requirements for the existence of certain statistical properties in discrete lattice gas systems are not directly inferred from those in real continuous systems, but are closely related. Hence understanding in detail the causes and results for lattice gas systems may provide further insights into fundamental microscopic physical processes.

scholarly journals Bifurcation Diagrams and Global Phase Portraits for Some Hamiltonian Systems with Rational Potentials

2018 ◽  
Vol 28 (13) ◽  
pp. 1850168
Author(s):  
Ting Chen ◽  
Jaume Llibre
Keyword(s):  
Hamiltonian System ◽  
Hamiltonian Systems ◽  
Normal Forms ◽  
Dynamical Behavior ◽  
Phase Portraits ◽  
Bifurcation Diagrams ◽  
Linear Change ◽  
Rational Potential ◽  
Change Of Variables ◽  
Poincaré Disk

In this paper, we study the global dynamical behavior of the Hamiltonian system [Formula: see text], [Formula: see text] with the rational potential Hamiltonian [Formula: see text], where [Formula: see text] and [Formula: see text] are polynomials of degree 1 or 2. First we get the normal forms for these rational Hamiltonian systems by some linear change of variables. Then we classify all the global phase portraits of these systems in the Poincaré disk and provide their bifurcation diagrams.

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