Non equilibrium phenomena in supercooled fluids, glasses and amorphous materials

Giordano, Marco; Leporini, Dino; Tosi, M. P.

doi:10.1142/9789814530774

Cited by 19 publications

(28 citation statements)

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“…Since their mutual interplay cannot be neglected both dynamical aspects must be jointly considered. If the liquids are supercooled or supercompressed the overwhelming difficulties to molecular rearrangement are expected to enhance the role of the rotational degrees of freedom and, more particularly, the rotationaltranslational coupling as noticed by experiments [1][2][3][4][5], theory [6][7][8] and numerical [9][10][11][12] studies and discussed in a recent topical meeting [13].…”

Section: Introductionmentioning

confidence: 99%

Viscous flow and jump dynamics in molecular supercooled liquids. II. Rotations

Michele

Leporini

2001

Phys. Rev. E

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The rotational dynamics of a supercooled model liquid of rigid A-B dumbbells interacting via a L-J potential is investigated along one single isobar. The orientation correlation functions exhibit a two-step character which evidences molecular trapping. Trapping is also apparent in a suitable angular-velocity correlation functions. The rotational correlation τ1 is found to scale over more than three orders of magnitude as (T − Tc)−γ with γ = 1.47 ± 0.01 and Tc the MCT critical temperature. Differently, τ l with l = 2 − 4 and the rotational diffusion coefficient Dr manifest deviations. For 0.7 < T < 2 good agreement with the diffusion model is found, i.e. τ l ∼ = 1/l(l + 1)Dr. For lower temperatures the agreement becomes poorer and the results are also only partially accounted for by the jump-rotation model. The angular Van Hove function evidences that in this region a meaningful fraction of the sample reorientates by jumps of about 180• . The distribution of the waiting-times in the angular sites cuts exponentially at long times. At lower temperatures it decays at short times as t ξ−1 with ξ = 0.34 ± 0.04 at T = 0.5 in analogy with the translational case. The breakdown of the Debye-Stokes-Einstein is observed at lower temperatures where the rotational correlation times diverge more weakly than the viscosity.

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Section: Introductionmentioning

confidence: 99%

Viscous flow and jump dynamics in molecular supercooled liquids. II. Rotations

Michele

Leporini

2001

Phys. Rev. E

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“…The relaxation phenomena and the tranport properties of supercooled liquids and glassy materials are topics of current interest [1,2]. It is well known that, on approaching the glass transition temperature T g from above, diffusion coefficients and relaxation times exhibit remarkable changes of several orders of magnitude which are under intense experimental, theoretical and numerical investigation.…”

Section: Introductionmentioning

confidence: 99%

Viscous flow and jump dynamics in molecular supercooled liquids. I. Translations

Michele

Leporini

2001

Phys. Rev. E

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The transport and relaxation properties of a molecular supercooled liquid on an isobar are studied by molecular dynamics. The molecule is a rigid heteronuclear biatomic system. The diffusivity is fitted over four orders of magnitude by the power law D proportional to (T-T(c))(gamma(D)), with gamma(D)=1.93+/-0.02 and T(c)=0.458+/-0.002. The self-part of the intermediate scattering function F(s)(k(max),t) exhibits a steplike behavior at the lowest temperatures. On cooling, the increase of the related relaxation time tau(alpha) tracks the diffusivity, i.e., tau(alpha) proportional to (k(2)(max)D)(-1). At the lowest temperatures, fractions of highly mobile and trapped molecules are also evidenced. Translational jumps are also evidenced. The duration of the jumps exhibits a distribution. The distribution of the waiting times before a jump takes place, psi(t), is exponential at higher temperatures. At lower temperatures a power-law divergence is evidenced at short times, psi(t) proportional to t(xi-1) with 0

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“…The characteristic stretched exponential behavior of S q ( r ) is difficult to see in the comparatively short observational climate records but can be observed in long historic and reconstructed climate records 56. Stretched exponential behavior appears in many other contexts, e.g., in materials science 59 (where it is known as Kohlrausch‐Williams‐Watts behavior) and in earth sciences 4. In Sect.…”

Section: Clustering Of Extreme Eventsmentioning

confidence: 99%

The Different Types of Noise and How They Effect Data Analysis

Bunde

2023

Chemie Ingenieur Technik

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Random (noisy) processes can be characterized by the way consecutive data are correlated. The data can be uncorrelated (white noise), short‐range correlated (often called red noise), or long‐range correlated (sometimes called pink noise). Here we describe the properties and applications of these different kinds of noise. We discuss, how they influence (i) the diffusion process, (ii) the occurrence of rare extreme events and (iii) the detection of an external trend that is superimposed on the noise; (ii) and (iii) are particularly relevant in the context of detecting anthropogenic global warming by data analysis.

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Non equilibrium phenomena in supercooled fluids, glasses and amorphous materials

Cited by 19 publications

References 0 publications

Viscous flow and jump dynamics in molecular supercooled liquids. II. Rotations

Viscous flow and jump dynamics in molecular supercooled liquids. II. Rotations

Viscous flow and jump dynamics in molecular supercooled liquids. I. Translations

The Different Types of Noise and How They Effect Data Analysis

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