Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. 24/7 Space News .




TIME AND SPACE
Enigmatic Nematics
by Staff Writers
Heidelberg, Germany (SPX) Nov 06, 2012


The authors coined the term self-propelled nematics to refer to internally driven elongated particles that spontaneously align head to tail, like tinned sardines.

Physicists use hydrodynamics to understand the physical mechanism responsible for changes in the long-range order of groups of particles. Particularly, Aparna Baskaran of Brandeis University, Massachusetts, USA, and Cristina Marchetti of Syracuse University, New York, USA, focused on ordered groups of elongated self-propelled particles.

They studied the breakdown of long-range order due to fluctuations that render them unstable and give rise to complex structures, in a study about to be published in EPJ E.

The authors coined the term self-propelled nematics to refer to internally driven elongated particles that spontaneously align head to tail, like tinned sardines. These are characterised by an ordered state that is stationary on average.

This means that there is a long-range order, i.e., the long axes of the molecules tend to align along a preferred direction, whereas the locally preferred direction may vary throughout the medium due to local strains or disturbances.

In this study, Baskaran and Marchetti first found that a uniform nematic state can be disturbed by density fluctuations associated with an upward current of active particles. Since the density in turn controls the onset of nematic order, this phenomenon is self-regulating and universal.

They also found that an instability can be triggered by a local distortion of particles' orientation. Such a distortion results in local currents that in turn amplify the distortion, leading to an instability deep inside the nematic state.

Future research will involve solving numerically the hydrodynamic equations to test the theory presented in this study and characterise the emergent structures.

Ultimately, this work may help us gain a deeper understanding of pattern formation and dynamics in a variety of internally driven systems, from epithelial cells and soil bacteria such as Myxococcus xanthus, to colloidal self-propelled nanorods.

A. Baskaran, M. C. Marchetti (2012), Self-regulation in Self-Propelled Nematic Fluids, European Physical Journal E 35:95, DOI 10.1140/epje/i2012-12095-8

.


Related Links
Springer
Understanding Time and Space






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





TIME AND SPACE
World record for the entanglement of twisted light quanta
Vienna, Austria (SPX) Nov 05, 2012
To this end, the researchers developed a new method for entangling single photons which gyrate in opposite directions. This result is a first step towards entangling and twisting even macroscopic, spatially separated objects in two different directions. The researchers at the Vienna Center for Quantum Science and Technology (VCQ), situated at the University of Vienna, and the Institute for ... read more


TIME AND SPACE
Moon crater yields impact clues

Study: Moon basin formed by giant impact

NASA's LADEE Spacecraft Gets Final Science Instrument Installed

Astrium presents results of its study into automatic landing near the Moon's south pole

TIME AND SPACE
Mars Longevity Champ Switching Computers

NASA Rover Finds Clues to Changes in Mars' Atmosphere

Survey Of Matijevic Hill Continues

Preliminary Self-Portrait of Curiosity by Rover's Arm Camera

TIME AND SPACE
Voyager observes magnetic field fluctuations in heliosheath

New NASA Online Science Resource Available for Educators and Students

'First' Pakistan astronaut wants to make peace in space

Space daredevil Baumgartner is 'officially retired'

TIME AND SPACE
Tiangong 1 Parked And Waiting As Shenzhou 10 Mission Prep Continues

China to launch 11 meteorological satellites by 2020

China makes progress in spaceflight research

Patience for Tiangong

TIME AND SPACE
Crew Prepares for Spacewalk After Progress Docks

Crew Preparing for Cargo Ship, Spacewalk

Russian cargo ship docks with ISS: official

Packed Week Ahead for Six-Member Crew

TIME AND SPACE
Russian Proton Briz-M Launches Yamal Satellites Into Orbit

SpaceX Transitions to Third Commercial Crew Phase with NASA

Globalstar Birds To Launch On Soyuz Next February

Ariane 5s are readied in parallel for Arianespace's next heavy-lift flights

TIME AND SPACE
Physicists confirm first planet discovered in a quadruple star system

Planet-hunt data released to public

New Study Brings a Doubted Exoplanet 'Back from the Dead'

New small satellite will study super-Earths for ESA

TIME AND SPACE
ORNL Debuts Titan Supercomputer

UNH Space Scientists to Develop State-of-the-Art Radiation Detector

Samsung muscle versus Apple's 'cool'

1.2 billion smartphones, tablets to sell in 2013: survey




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement