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

Torque On A Current Loop In A Magnetic Field01:13

Torque On A Current Loop In A Magnetic Field

4.6K
The most common application of magnetic force on current-carrying wires is in electric motors. These consist of loops of wire, which are placed between the magnets with a magnetic field. When current flows through the loops, the magnetic field applies torque, which causes the shaft to rotate, thus converting electrical energy to mechanical energy.
Consider a rectangular current-carrying loop containing N turns of wire, placed in a uniform magnetic field. The net force on a current-carrying loop...
4.6K
Three-Dimensional Force System:Problem Solving01:30

Three-Dimensional Force System:Problem Solving

813
A three-dimensional force system refers to a scenario in which three forces act simultaneously in three different directions. This type of problem is commonly encountered in physics and engineering, where it is necessary to calculate the resultant force on the system, which can then be used to predict or analyze the behavior of the object or structure under consideration.
To solve a three-dimensional force system, first resolve each force into its respective scalar components. Do this using...
813
Plastic Deformations of Members with a Single Plane of Symmetry01:21

Plastic Deformations of Members with a Single Plane of Symmetry

121
When a structural member undergoes plastic deformation due to bending, it is crucial to understand the position of the neutral axis and the stress distribution. This member, characterized by a single plane of symmetry, exhibits a uniform stress distribution, with negative stress above the neutral axis and positive stress below. Notably, the neutral axis does not align with the centroid of the cross-section. This misalignment is typical in cases where the cross-section is not rectangular or...
121
Three-Dimensional Force System01:30

Three-Dimensional Force System

2.2K
In mechanical engineering, a three-dimensional force system is a system of forces acting in three dimensions, with forces applied along the x, y, and z coordinate axes. The three-dimensional force system is an important concept in mechanical engineering, as it allows engineers to understand and analyze the behavior of objects and structures in three dimensions. By understanding the forces acting on a system, engineers can design more efficient and effective mechanical systems that can withstand...
2.2K
Equations of Equilibrium in Three Dimensions01:30

Equations of Equilibrium in Three Dimensions

1.3K
When analyzing structures or systems at rest, it is necessary to ensure they are in equilibrium. This is where the vector and scalar equations of equilibrium come into play. These equations are crucial in ensuring a structure is stable and will not collapse or fall apart. The vector and scalar equations of equilibrium provide a framework for analyzing the forces acting on a body.
According to the vector equations of equilibrium, the vector sum of all the external forces acting on a body must...
1.3K
Symmetry in Maxwell's Equations01:28

Symmetry in Maxwell's Equations

3.6K
Once the fields have been calculated using Maxwell's four equations, the Lorentz force equation gives the force that the fields exert on a charged particle moving with a certain velocity. The Lorentz force equation combines the force of the electric field and of the magnetic field on the moving charge. Maxwell's equations and the Lorentz force law together encompass all the laws of electricity and magnetism. The symmetry that Maxwell introduced into his mathematical framework may not be...
3.6K

You might also read

Related Articles

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

Sort by
Same author

Screw symmetry, chiral hydrodynamics, and odd instability in active cholesterics.

Physical review. E·2025
Same author

Contributed Talks I: Fixational eye movements and retinal adaptation: optimizing drift to maximize information acquisition.

Journal of vision·2025
Same author

Chirality and odd mechanics in active columnar phases.

PNAS nexus·2024
Same author

Contact Topology and the Classification of Disclination Lines in Cholesteric Liquid Crystals.

Physical review letters·2023
Same author

Threading Dynamics of Ring Polymers in a Gel.

ACS macro letters·2022
Same author

Layered Chiral Active Matter: Beyond Odd Elasticity.

Physical review letters·2021
Same journal

Erratum: Low-dimensional model for adaptive networks of spiking neurons [Phys. Rev. E 111, 014422 (2025)].

Physical review. E·2026
Same journal

Disentangling the effects of many-body forces on depletion interactions.

Physical review. E·2026
Same journal

Charge transport and mode transition in dual-energy electron beam diodes.

Physical review. E·2026
Same journal

Optimization of multisite reactions in complex compartmentalized media.

Physical review. E·2026
Same journal

Origin of geometric cohesion in nonconvex granular materials: Interplay between interdigitation and rotational constraints enhancing frictional stability.

Physical review. E·2026
Same journal

Interaction of walkers with a standing Faraday wave.

Physical review. E·2026
See all related articles

Related Experiment Video

Updated: Sep 4, 2025

Forming, Confining, and Observing Microtubule-Based Active Nematics
08:37

Forming, Confining, and Observing Microtubule-Based Active Nematics

Published on: January 13, 2023

2.8K

Defect loops in three-dimensional active nematics as active multipoles.

Alexander J H Houston1, Gareth P Alexander1,2

  • 1Department of Physics, Gibbet Hill Road, University of Warwick, Coventry CV4 7AL, United Kingdom.

Physical Review. E
|July 20, 2022
PubMed
Summary
This summary is machine-generated.

Defect loops in active nematics exhibit self-propulsion and self-orientation due to active stresses and torques. Certain twist loop geometries are force- and torque-free, potentially explaining their prevalence.

More Related Videos

Tuning the Contractility and Deformation Modes of Active Actin-Based Assemblies In Vitro: From Two-Dimensional Active Networks to Liquid Crystal Drops
06:48

Tuning the Contractility and Deformation Modes of Active Actin-Based Assemblies In Vitro: From Two-Dimensional Active Networks to Liquid Crystal Drops

Published on: July 11, 2025

464
Controlling Flow Speeds of Microtubule-Based 3D Active Fluids Using Temperature
08:04

Controlling Flow Speeds of Microtubule-Based 3D Active Fluids Using Temperature

Published on: November 26, 2019

7.3K

Related Experiment Videos

Last Updated: Sep 4, 2025

Forming, Confining, and Observing Microtubule-Based Active Nematics
08:37

Forming, Confining, and Observing Microtubule-Based Active Nematics

Published on: January 13, 2023

2.8K
Tuning the Contractility and Deformation Modes of Active Actin-Based Assemblies In Vitro: From Two-Dimensional Active Networks to Liquid Crystal Drops
06:48

Tuning the Contractility and Deformation Modes of Active Actin-Based Assemblies In Vitro: From Two-Dimensional Active Networks to Liquid Crystal Drops

Published on: July 11, 2025

464
Controlling Flow Speeds of Microtubule-Based 3D Active Fluids Using Temperature
08:04

Controlling Flow Speeds of Microtubule-Based 3D Active Fluids Using Temperature

Published on: November 26, 2019

7.3K

Area of Science:

  • Physics
  • Soft Matter Physics
  • Active Matter

Background:

  • Active nematics are complex fluids with self-propulsion.
  • Defect loops are topological structures within these systems.
  • Understanding their dynamics is crucial for active matter physics.

Purpose of the Study:

  • To describe the self-dynamics of defect loops in 3D active nematics.
  • To link loop geometry to self-propulsion and self-orientation.
  • To identify force- and torque-free defect loop configurations.

Main Methods:

  • Multipole expansion of the far-field director.
  • Analysis of dipole and quadrupole moments.
  • Determination of Stokesian flows and hydrodynamics.

Main Results:

  • Dipole terms induce self-propulsion in splay and bend loops.
  • Nonplanar loops generate active torques, leading to self-orientation.
  • Right- and left-handed twist loops are force- and torque-free.

Conclusions:

  • Loop geometry dictates self-dynamics in active nematics.
  • Active stresses and torques drive loop motion and orientation.
  • A mechanism for twist loop excess is proposed based on force-free geometries.