Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Behavior of Gas Molecules: Molecular Diffusion, Mean Free Path, and Effusion03:48

Behavior of Gas Molecules: Molecular Diffusion, Mean Free Path, and Effusion

28.8K
Although gaseous molecules travel at tremendous speeds (hundreds of meters per second), they collide with other gaseous molecules and travel in many different directions before reaching the desired target. At room temperature, a gaseous molecule will experience billions of collisions per second. The mean free path is the average distance a molecule travels between collisions. The mean free path increases with decreasing pressure; in general, the mean free path for a gaseous molecule will be...
28.8K
Standard Entropy Change for a Reaction03:00

Standard Entropy Change for a Reaction

20.3K
Entropy is a state function, so the standard entropy change for a chemical reaction (ΔS°rxn) can be calculated from the difference in standard entropy between the products and the reactants.
20.3K
Entropy02:39

Entropy

29.4K
Salt particles that have dissolved in water never spontaneously come back together in solution to reform solid particles. Moreover, a gas that has expanded in a vacuum remains dispersed and never spontaneously reassembles. The unidirectional nature of these phenomena is the result of a thermodynamic state function called entropy (S). Entropy is the measure of the extent to which the energy is dispersed throughout a system, or in other words, it is proportional to the degree of disorder of a...
29.4K
Free Energy Changes for Nonstandard States03:25

Free Energy Changes for Nonstandard States

11.4K
The free energy change for a process taking place with reactants and products present under nonstandard conditions (pressures other than 1 bar; concentrations other than 1 M) is related to the standard free energy change according to this equation:
 
where R is the gas constant (8.314 J/K·mol), T is the absolute temperature in kelvin, and Q is the reaction quotient. This equation may be used to predict the spontaneity of a process under any given set of conditions.
Reaction Quotient...
11.4K
Entropy within the Cell01:22

Entropy within the Cell

10.5K
A living cell's primary tasks of obtaining, transforming, and using energy to do work may seem simple. However, the second law of thermodynamics explains why these tasks are harder than they appear. None of the energy transfers in the universe are completely efficient. In every energy transfer, some amount of energy is lost in a form that is unusable. In most cases, this form is heat energy. Thermodynamically, heat energy is defined as the energy transferred from one system to another that...
10.5K
Gibbs Free Energy and Thermodynamic Favorability02:23

Gibbs Free Energy and Thermodynamic Favorability

6.8K
The spontaneity of a process depends upon the temperature of the system. Phase transitions, for example, will proceed spontaneously in one direction or the other depending upon the temperature of the substance in question. Likewise, some chemical reactions can also exhibit temperature-dependent spontaneities. To illustrate this concept, the equation relating free energy change to the enthalpy and entropy changes for the process is considered:
6.8K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Effect of Savings on a Gas-Like Model Economy with Credit and Debt.

Entropy (Basel, Switzerland)·2021
See all related articles

Related Experiment Video

Updated: Jun 23, 2025

The Diffusion of Passive Tracers in Laminar Shear Flow
08:01

The Diffusion of Passive Tracers in Laminar Shear Flow

Published on: May 1, 2018

8.5K

Entropy Production in Reaction-Diffusion Systems Confined in Narrow Channels.

Guillermo Chacón-Acosta1, Mayra Núñez-López2

  • 1Applied Mathematics and Systems Department, Universidad Autónoma Metropolitana-Cuajimalpa, Vasco de Quiroga 4871, Mexico City 05348, Mexico.

Entropy (Basel, Switzerland)
|June 26, 2024
PubMed
Summary

Confining a reaction-diffusion system to a narrow channel alters entropy production density. Wall geometry modifies entropy values but not its fundamental behavior, aiding structure formation studies.

Keywords:
Gray–Scott modeldiffusion in confinemententropy productionnarrow channelspattern formationreaction–diffusion systems

More Related Videos

A Scalable Balz-Schiemann Reaction Protocol in a Continuous Flow Reactor
05:21

A Scalable Balz-Schiemann Reaction Protocol in a Continuous Flow Reactor

Published on: February 10, 2023

3.0K
Unraveling Entropic Rate Acceleration Induced by Solvent Dynamics in Membrane Enzymes
09:42

Unraveling Entropic Rate Acceleration Induced by Solvent Dynamics in Membrane Enzymes

Published on: January 16, 2016

9.0K

Related Experiment Videos

Last Updated: Jun 23, 2025

The Diffusion of Passive Tracers in Laminar Shear Flow
08:01

The Diffusion of Passive Tracers in Laminar Shear Flow

Published on: May 1, 2018

8.5K
A Scalable Balz-Schiemann Reaction Protocol in a Continuous Flow Reactor
05:21

A Scalable Balz-Schiemann Reaction Protocol in a Continuous Flow Reactor

Published on: February 10, 2023

3.0K
Unraveling Entropic Rate Acceleration Induced by Solvent Dynamics in Membrane Enzymes
09:42

Unraveling Entropic Rate Acceleration Induced by Solvent Dynamics in Membrane Enzymes

Published on: January 16, 2016

9.0K

Area of Science:

  • Chemical kinetics and thermodynamics
  • Complex systems and pattern formation

Background:

  • Reaction-diffusion systems are fundamental to understanding pattern formation in nature.
  • Entropy production is a key thermodynamic quantity governing system evolution.
  • Confining these systems to micro/nanochannels introduces geometric constraints.

Purpose of the Study:

  • To investigate the impact of channel wall geometry on entropy production density.
  • To analyze the reversible Gray-Scott reaction-diffusion system under geometric confinement.
  • To understand how geometric modifications affect the exploration of structure-formation.

Main Methods:

  • Utilized an effective diffusion equation incorporating channel geometry modifications.
  • Analyzed the entropy production density within the confined reaction-diffusion system.
  • Studied the reversible Gray-Scott model as a representative system.

Main Results:

  • Channel geometry was found to alter the quantitative value of entropy density.
  • The qualitative behavior of entropy density remained unchanged despite geometric modifications.
  • The findings provide insights into how confinement influences system dynamics.

Conclusions:

  • Wall geometry in confined reaction-diffusion systems modulates entropy production quantitatively.
  • The qualitative nature of entropy production is robust to geometric variations.
  • This research facilitates a deeper understanding of structure formation in constrained environments.