Related Experiment Video
Updated: Aug 5, 2026
10:03
Uncoupling Coriolis Force and Rotating Buoyancy Effects on Full-Field Heat Transfer Properties of a Rotating Channel
Published on: October 5, 2018
Inverse Clausius Thermodynamics in Run-and-Tumble Dynamics
1Ben-Gurion University of the Negev, Department of Biomedical Engineering, Be'er Sheva 85105, Israel.
Physical Review Letters
|July 31, 2026
Summary
This study maps run-and-tumble particle dynamics to Brownian motion using an inverse thermodynamic framework. It reveals how entropy flows from hotter to colder regions, applicable to various potentials.
Area of Science:
- Statistical Mechanics
- Non-equilibrium Thermodynamics
- Soft Matter Physics
Background:
- Run-and-tumble (RT) particle dynamics are crucial for modeling active matter, but their thermodynamic properties are complex.
- Brownian motion in inhomogeneous temperature fields offers a simpler, yet related, physical system.
- Connecting these systems can provide new insights into entropy production and transport.
Purpose of the Study:
- To establish a theoretical framework connecting 1D RT particle dynamics with thermal noise to overdamped Brownian motion in spatially varying temperature fields.
- To develop a method for inferring local entropy flux and production rates from steady-state observables.
- To analyze the relationship between entropy transfer and effective temperature gradients.
Main Methods:
- Formulation of an inverse-Clausius thermodynamic framework to infer effective temperature from steady-state particle density.
- Development of a closure relation linking entropy flow to spatial variations in effective temperature.
- Application and validation of the framework to 1D RT models (two-state and multistate) in harmonic and nonlinear potentials.
Main Results:
- A direct mapping was established between RT dynamics and Brownian motion in inhomogeneous temperature fields.
- The framework allows extraction of entropy flux and production rates from steady-state densities.
- Entropy transfer from hotter to colder regions was demonstrated, with the closure relation showing high accuracy for harmonic and locally confining nonlinear potentials.
- Deviations in non-confining potentials highlighted the need for higher-order corrections and revealed links between entropy production and potential structure.
Conclusions:
- The inverse-Clausius framework provides a powerful tool for analyzing non-equilibrium thermodynamics of RT particles.
- The study elucidates the fundamental process of entropy transfer driven by effective temperature gradients.
- The findings offer a new perspective on the statistical mechanics of active matter and its relation to passive thermal systems.
Related Concept Videos
01:29The Clausius–Clapeyron Equation
The Clausius-Clapeyron equation is a fundamental principle in physical chemistry and thermodynamics that describes the relationship between a substance's vapor pressure and temperature. Named after Rudolf Clausius and Benoît Paul Émile Clapeyron, the equation is integral in predicting a substance's behavior under different temperature conditions.The Clausius-Clapeyron equation allows us to calculate how the pressure at which a liquid boils (its vapor pressure) changes as the temperature changes.
02:35Clausius-Clapeyron Equation
The equilibrium between a liquid and its vapor depends on the temperature of the system; a rise in temperature causes a corresponding rise in the vapor pressure of its liquid. The Clausius-Clapeyron equation gives the quantitative relation between a substance’s vapor pressure (P) and its temperature (T); it predicts the rate at which vapor pressure increases per unit increase in temperature.
01:21Path Between Thermodynamics States
Consider the two thermodynamic processes involving an ideal gas that are represented by paths AC and ABC in Figure 1:
01:24Thermodynamics: Activity Coefficient
Activity is the measure of the effective concentration of the species in solution. It can be expressed as the product of the molar concentration of the species and its activity coefficient. The activity coefficient is a dimensionless quantity and depends on the total ionic strength of the solution.
The activity coefficient is a measure of the deviation from ideal behavior. When the ionic strength of the solution is minimal, the activity coefficient of an ionic species is close to unity, making...
The activity coefficient is a measure of the deviation from ideal behavior. When the ionic strength of the solution is minimal, the activity coefficient of an ionic species is close to unity, making...
01:28The Thermodynamics of Mixing
Mixing is a fascinating phenomenon in thermodynamics, particularly when considering the Gibbs energy of a mixture at constant temperature and pressure. This energy, denoted as G, tends to decrease during spontaneous mixing processes, offering insights into the composition changes that occur.Imagine two ideal gases, initially separated in different containers, with amounts nA and nB, respectively, both at a temperature T and pressure p. The chemical potentials of these gases have their 'pure'...
01:15Statements of the Second Law of Thermodynamics
The second law of thermodynamics can be stated in several different ways, and all of them can be shown to imply the others. The Clausius’ statement of the second law of thermodynamics is based on the irreversibility of spontaneous heat flow. It states that heat will not flow from the colder body to the hotter body unless some other process is involved. Additionally, as per the Kelvin’s statement, it is impossible to convert the heat from a single source into work without any other effect. This...