As-Quenched ARC Products By bulse - Discharge

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.

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Quantitative analysis of non-equilibrium systems from short-time experimental data

10.21203/rs.3.rs-310152/v1 ◽

2021 ◽

Author(s):

Sreekanth K Manikandan ◽

Subhrokoli Ghosh ◽

Avijit Kundu ◽

Biswajit Das ◽

Vipin Agrawal ◽

...

Keyword(s):

Experimental Data ◽

Steady State ◽

Quantitative Analysis ◽

Large Class ◽

Colloidal Particle ◽

Particle System ◽

Thermodynamic Force ◽

Trajectory Data ◽

Short Time ◽

Non Equilibrium

Abstract We provide a minimal strategy for the quantitative analysis of a large class of non-equilibrium systems in a steady state using the short-time Thermodynamic Uncertainty Relation (TUR). From short-time trajectory data obtained from experiments, we demonstrate how we can simultaneously infer quantitatively, both the thermodynamic force field acting on the system, as well as the exact rate of entropy production. We benchmark this scheme first for an experimental study of a colloidal particle system where exact analytical results are known, before applying it to the case of a colloidal particle in a hydrodynamical flow field, where neither analytical nor numerical results are available. Our scheme hence provides a means, potentially exact for a large class of systems, to get a quantitative estimate of the entropy produced in maintaining a non-equilibrium system in a steady state, directly from experimental data.

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Supradegeneracy and the Second Law of Thermodynamics

Journal of Non-Equilibrium Thermodynamics ◽

10.1515/jnet-2019-0051 ◽

2020 ◽

Vol 45 (2) ◽

pp. 121-132

Author(s):

Daniel P. Sheehan

Keyword(s):

Steady State ◽

Statistical Mechanics ◽

Population Inversion ◽

Laboratory Experiments ◽

Second Law Of Thermodynamics ◽

Second Law ◽

Boltzmann Factor ◽

Energy Currents ◽

Non Equilibrium

AbstractCanonical statistical mechanics hinges on two quantities, i. e., state degeneracy and the Boltzmann factor, the latter of which usually dominates thermodynamic behaviors. A recently identified phenomenon (supradegeneracy) reverses this order of dominance and predicts effects for equilibrium that are normally associated with non-equilibrium, including population inversion and steady-state particle and energy currents. This study examines two thermodynamic paradoxes that arise from supradegeneracy and proposes laboratory experiments by which they might be resolved.

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Modules or Mean-Fields?

Entropy ◽

10.3390/e22050552 ◽

2020 ◽

Vol 22 (5) ◽

pp. 552 ◽

Cited By ~ 2

Author(s):

Thomas Parr ◽

Noor Sajid ◽

Karl J. Friston

Keyword(s):

Steady State ◽

Message Passing ◽

Mean Field Theory ◽

Functional Anatomy ◽

Mean Field ◽

State Density ◽

Stochastic Dynamical Systems ◽

Conditional Independency ◽

The Brain ◽

Non Equilibrium

The segregation of neural processing into distinct streams has been interpreted by some as evidence in favour of a modular view of brain function. This implies a set of specialised ‘modules’, each of which performs a specific kind of computation in isolation of other brain systems, before sharing the result of this operation with other modules. In light of a modern understanding of stochastic non-equilibrium systems, like the brain, a simpler and more parsimonious explanation presents itself. Formulating the evolution of a non-equilibrium steady state system in terms of its density dynamics reveals that such systems appear on average to perform a gradient ascent on their steady state density. If this steady state implies a sufficiently sparse conditional independency structure, this endorses a mean-field dynamical formulation. This decomposes the density over all states in a system into the product of marginal probabilities for those states. This factorisation lends the system a modular appearance, in the sense that we can interpret the dynamics of each factor independently. However, the argument here is that it is factorisation, as opposed to modularisation, that gives rise to the functional anatomy of the brain or, indeed, any sentient system. In the following, we briefly overview mean-field theory and its applications to stochastic dynamical systems. We then unpack the consequences of this factorisation through simple numerical simulations and highlight the implications for neuronal message passing and the computational architecture of sentience.

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Non-equilibrium properties of a flowing hydrogen cascaded arc plasma: kinetic modelling

Journal of Physics D Applied Physics ◽

10.1088/0022-3727/29/8/008 ◽

1996 ◽

Vol 29 (8) ◽

pp. 2111-2118 ◽

Cited By ~ 4

Author(s):

V P Silakov ◽

A A Matveyev ◽

A V Chebotarev ◽

D K Otorbaev

Keyword(s):

Kinetic Modelling ◽

Arc Plasma ◽

Plasma Kinetic ◽

Flowing Hydrogen ◽

Non Equilibrium

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

Physica Scripta ◽

10.1088/0031-8949/39/1/004 ◽

1989 ◽

Vol 39 (1) ◽

pp. 33-39 ◽

Cited By ~ 2

Author(s):

Antonis D Mistriotis

Keyword(s):

Hamiltonian Systems ◽

Dynamical Behavior ◽

Statistical Properties ◽

Short Time ◽

Non Equilibrium

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Lifshitz hydrodynamics at generic z from a moving black brane

Journal of High Energy Physics ◽

10.1007/jhep07(2021)197 ◽

2021 ◽

Vol 2021 (7) ◽

Author(s):

Aruna Rajagopal ◽

Larus Thorlacius

Keyword(s):

Field Theory ◽

Steady State ◽

Critical Exponent ◽

Stress Tensor ◽

Perfect Fluid ◽

Scale Invariance ◽

Linear Momentum ◽

Black Brane ◽

Dilaton Gravity ◽

Non Equilibrium

Abstract A Lifshitz black brane at generic dynamical critical exponent z > 1, with non-zero linear momentum along the boundary, provides a holographic dual description of a non-equilibrium steady state in a quantum critical fluid, with Lifshitz scale invariance but without boost symmetry. We consider moving Lifshitz branes in Einstein-Maxwell-Dilaton gravity and obtain the non-relativistic stress tensor complex of the dual field theory via a suitable holographic renormalisation procedure. The resulting black brane hydrodynamics and thermodynamics are a concrete holographic realization of a Lifshitz perfect fluid with a generic dynamical critical exponent.

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