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

Entropy Change in Reversible Processes01:10

Entropy Change in Reversible Processes

2.9K
In the Carnot engine, which achieves the maximum efficiency between two reservoirs of fixed temperatures, the total change in entropy is zero. The observation can be generalized by considering any reversible cyclic process consisting of many Carnot cycles. Thus, it can be stated that the total entropy change of any ideal reversible cycle is zero.
The statement can be further generalized to prove that entropy is a state function. Take a cyclic process between any two points on a p-V diagram.
2.9K
Entropy01:18

Entropy

3.1K
The first law of thermodynamics is quantitatively formulated via an equation relating the internal energy of a system, the heat exchanged by it, and the work done on it. A quantitative formulation of the second law of thermodynamics leads to defining a state function, the entropy.
When an ideal gas expands isothermally, the disorder in the gas increases. From the molecular perspective, the gas molecules have more volume to move around in.
Consider an infinitesimal step in the expansion, which...
3.1K
Entropy02:39

Entropy

32.4K
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...
32.4K
The Carnot Cycle and the Second Law of Thermodynamics01:20

The Carnot Cycle and the Second Law of Thermodynamics

3.1K
The Carnot engine works between two heat reservoirs of fixed temperatures. The Carnot cycle begs the following question: Is it possible to devise a heat engine that is more efficient than a Carnot engine between two fixed temperatures? The answer lies in designing a Carnot refrigerator.
Since the individual steps in a Carnot cycle can be reversed, the entire cycle is, thus, reversible. If a Carnot cycle is reversed, it becomes a Carnot refrigerator. It extracts heat Qc from a cold reservoir at...
3.1K
The Carnot Cycle01:30

The Carnot Cycle

3.4K
Converting work to heat is an irreversible process, and the purpose of a heat engine is to reverse the effect partially. Heat engines aim to increase the efficiency of the reversal, that is, maximize the work retrieved from heat. If the efficiency of a heat engine were 100%, it would imply reversing the process completely without introducing any other effect. Thus, it would violate the second law of thermodynamics.
What could be the theoretical limit to the efficiency of a heat engine? The...
3.4K
Reversible and Irreversible Processes01:14

Reversible and Irreversible Processes

4.9K
The thermodynamic processes can be classified into reversible and irreversible processes. The processes that can be restored to their initial state are called reversible processes. It is only possible if the process is in quasi-static equilibrium, i.e., it takes place in infinitesimally small steps, and the system remains at equilibrium However, these are ideal processes and do not occur naturally. An ideal system undergoing a reversible process is always in thermodynamic equilibrium within...
4.9K

You might also read

Related Articles

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

Sort by
Same author

Muscle-Invasive Bladder Cancer in Patients with Liver Cirrhosis: A Review of Pertinent Considerations.

Bladder cancer (Amsterdam, Netherlands)·2024
Same author

Successful Same-Day Discharge for Robot-Assisted Radical Prostatectomy: A Systematic Review and Meta-Analysis.

Urology practice·2023
Same author

Reply by Authors.

Urology practice·2023
Same author

Performance Feedback May Not Improve Radical Prostatectomy Outcomes: The Surgical Report Card (SuRep) Study.

The Journal of urology·2021
Same author

The Role of Metal-on-Metal Bearings in Total Hip Arthroplasty and Hip Resurfacing: Review Article.

HSS journal : the musculoskeletal journal of Hospital for Special Surgery·2017
Same author

Facile fingerstick insulin analysis: Application to monitoring postprandial insulin responses to snack foods.

Journal of diabetes·2010

Related Experiment Video

Updated: Oct 30, 2025

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

9.2K

The Carnot Cycle, Reversibility and Entropy.

David Sands1

  • 1Department of Physics and Mathematics, University of Hull, Hull HU6 7RX, UK.

Entropy (Basel, Switzerland)
|July 2, 2021
PubMed
Summary

The Carnot cycle

Area of Science:

  • Thermodynamics
  • Statistical Mechanics

Background:

  • The Carnot cycle and concepts of reversibility and entropy are examined.
  • Clausius's nineteenth-century ideas on entropy are linked to the outdated concept of heat as motion.
  • This historical view created a conflict between entropy and energy conservation.

Purpose of the Study:

  • To investigate reversibility and irreversibility using a macroscopic formulation of internal damping mechanisms.
  • To analyze the nature of work processes involving pressure changes.
  • To explore the conditions under which a Carnot cycle can be dynamically traced.

Main Methods:

  • Macroscopic formulation of internal damping mechanisms.
  • Rate equations for energy distribution within a gas.
  • Analysis of work processes with step changes in external pressure.
Keywords:
Carnot cycleClausiusentropyirreversibilityreversibility

More Related Videos

A Rapid Method for Modeling a Variable Cycle Engine
04:58

A Rapid Method for Modeling a Variable Cycle Engine

Published on: August 13, 2019

7.7K
Rapid PCR Thermocycling using Microscale Thermal Convection
09:02

Rapid PCR Thermocycling using Microscale Thermal Convection

Published on: March 5, 2011

23.0K

Related Experiment Videos

Last Updated: Oct 30, 2025

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

9.2K
A Rapid Method for Modeling a Variable Cycle Engine
04:58

A Rapid Method for Modeling a Variable Cycle Engine

Published on: August 13, 2019

7.7K
Rapid PCR Thermocycling using Microscale Thermal Convection
09:02

Rapid PCR Thermocycling using Microscale Thermal Convection

Published on: March 5, 2011

23.0K

Main Results:

  • Work processes with even small pressure changes are intrinsically irreversible.
  • Under ideal conditions (zero damping), a gas expands along equilibrium states.
  • A dynamic Carnot cycle can be traced in P-V space, distinct from quasi-static cycles.

Conclusions:

  • Clausius's entropy definition contains an inherent conflict with energy conservation.
  • Reversibility in thermodynamic processes is critically dependent on the absence of damping.
  • Dynamic cycles, unlike quasi-static ones, involve piston kinetic energy.