All Questions
Tagged with equilibrium non-equilibrium
34
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Pressure difference between a box and the outside atmosphere
Say I have a box of volume $V$, with an ideal gas inside it with temperature $T_b$. I don't know the number of particles inside it. The box is surrounded by the room's environment, which has ...
- 143
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Whether there is an isolated system, it will enter equilibrium [duplicate]
For a thermodynamically isolated system, will it eventually move toward thermal equilibrium? Will there be exceptions to the system?
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54
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Is it possible to define concepts like free energy in the diffusion process?
How does the idea of free energy (which we derive from the canonical partition function) fit in the domain of non-equilibrium processes like diffusion?
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How can an object on top of a Norton dome start to move?
The Norton dome is a dome-shaped surface in a gravity field on the top of which a symmetrical object is placed in perfect balance.
According to Newtonian determinism, the object will remain in balance ...
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58
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Time-Independent Quantum Hamiltonians and Thermodynamic Equilibrium
Suppose we have a time-independent Hamiltonian operator $\hat{H}$ of some system. We know that we can express the canonical partition function of said system as $z = \text{Tr}(e^{\beta\hat{H}})$ for ...
- 437
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High wire artist
We want to derive a Lagrangian equations for a high wire artist which uses a balancing rod for stability purposes. We know the masses and the polar moment of inertia of the artist and the rod.
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Is entropy maximum in equilibrium?
Usually, in the context of non-equilibrium thermodynamics, it is said that entropy achieves a maximum in equilibrium, so the Taylor series expansion of entropy around the equilibrium state as a ...
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If quantum Liouville's equation describes nonequilibrium evolution of the density matrix, why its derivation assumes time-independent probabilities?
For an ensemble characterized by the states $\{|n\rangle\}$ with probabilities $p_n$ at time $t$, the density operator is defined as $$\rho\equiv \sum\limits_n p_n|n\rangle\langle n|.$$ Assuming that ...
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Does Heat Equation really describe thermodynamic temperature?
We learnt that in the first PDE course, temperature profile could be described by heat equation.
\begin{align}
\frac{\partial{u}}{\partial t} \;=\; \alpha \nabla^{2}u \tag{1} \label{heat-eqn}
\end{...
- 1,083
4
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362
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Can Liouville's theorem describe the passage from nonequilibrium to equilibrium?
Let an isolated system starts in a nonequilibrium state at a time $t=0$. Then it is left undisturbed so that at a later time $t>0$, it comes to equilibrium. When it reaches equilibrium, the number ...
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What is the fundamental difference between equilibrium and non-equilibrium thermodynamics?
Can we use the formalism of equilibrium thermodynamics for a system that is in non-equilibrium steady state?
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Where can I find careful discussions of equilibrium?
I want to know what physical equilibrium is precisely. I'd like to understand dynamical equilibrium vs. static equilibrium, and I'd like to understand approaches to understand non-equilibrium ...
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Is thermodynamics only applicable to systems in equilibrium?
So I was going through callen's thermodynamics book and their he says that thermodynamics is only applicable to systems which are in equilibrium and that naturally raised a few questions in my mind
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- 543
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145
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Equilibrium and non-equilibrium thermodynamic states?
I have the following two states. I have classified them as equilibrium and non-equilibrium and I am not sure if that is the right category my problem is I need to understand what parameters to look ...
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Can spontaneous fluctuations cause instantaneous non-equilibrium?
The fluctuation-dissipation theorem says that the linear response of a given system to an external perturbation is expressed as the fluctuation properties of the system in thermal equilibrium.
Does ...
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