Subscribe to our free daily newsletters
. 24/7 Space News .




Subscribe to our free daily newsletters



TECH SPACE
Glass's off-kilter harmonies
by Staff Writers
Austin TX (SPX) Jan 20, 2017


Asegun Henry, Professor of Mechanical Engineering at Georgia Tech. Watch a video on the research here.

Asegun Henry wants to avert the worst effects of climate change by finding new forms of renewable energy and improving the materials that contribute to energy use. "The way we produce electricity today pollutes the environment," said Henry, a mechanical engineering professor at Georgia Tech. "My research is primarily centered on converting us from a fossil fuel-based infrastructure to a renewable- or solar-based infrastructure so we can rely on renewable forms of energy that don't pollute the world at all.

"I personally see that as saving the world."

What makes Henry's approach to energy problems different from other engineers is his background in atomic-level computer modeling.

"I understand different processes in terms of what's going on at the atomic level," Henry said. "That allows me to develop insights and opportunities for new ideas that are different from others that are coming from the macroscopic level."

His research is largely interested in how heat transport works at the smallest scales.

In October, Henry published the results of a study of amorphous silicon dioxide - commonly known as glass - in Nature Scientific Reports that answered a longstanding mystery about the everyday material: why its thermal conductivity rises with temperature.

The transport of heat in amorphous silicon is determined by the behavior of phonons in the material. Phonons are similar to electrons or photons, in that they carry heat, but instead of deriving from electromagnetic radiation or negatively charged subatomic particles, they are associated with the collective vibrations of atoms.

Scientists can accurately predict the thermal conductivity of many crystalline materials using expressions based on the widely-used "phonon gas model". However, modeling heat transfer in amorphous materials - those that lack the order and periodicity of a crystal - is more challenging.

"Unlike crystalline materials, where the vibrations become collective motions that act like sound waves, in amorphous materials, you get a different kinds of vibrations, the majority of which look random, like the underlying structure," Henry explained. "You even get small, localized vibrations that consist of only dozens of atoms."

These small vibrations were known to exist, but no one had ever assessed how much they contribute to heat transfer.

"The assumption was that they don't contribute at all," Henry said. "But what was surprising that we found with our new method was that in this specific material, the localized modes contribute substantially."

Using the Stampede supercomputer at the Texas Advanced Computing Center - one of the most powerful in the world - Henry ran simulations that captured the behavior of localized vibrations as never before.

Not only did the results match experimental results, they found that localized modes contributed more than 10 percent to the total thermal conductivity and are largely responsible for the increase in thermal conductivity of amorphous silicon above room temperature.

"These calculations that are being done are intractable on a single machine. You'd wait years to get the answer," he said. "To be able to break the problem into hundreds or thousands of individual parts that run concurrently, and do it massively in parallel is completely enabling."

The thermal conductivity of glass happens to be important for energy efficiency.

"Double digit percentages of all energy use in the U.S. is related to glass," Henry said. "The main place you lose heat is through windows."

Not only that: amorphous silicon is used in solar cells, and most polymers - plastics - such as those used in personal electronics, are composed of amorphous materials.

Henry's successes in capturing the atomic vibrations of glass was due to the development of a new way of studying the dynamics of phonons, which he'd created with with Wei Lv, a doctoral student in his lab, Known as Green-Kubo Modal Analysis (GKMA), the new method uses molecular dynamics simulations to more accurately calculate the contributions different modes of vibration make to the heat conduction.

In December 2016, Henry and Lv published a broad analysis of GKMA versus the phonon gas model in Nature Scientific Reports. Their results strongly suggest that the phonon gas model is not applicable to amorphous solids. The research is supported in part by a National Science Foundation (NSF) CAREER Award.

The GKMA method can be applied to a wide range of materials, including alloys, other amorphous solids and even rigid molecules.

Understanding and accurately modeling these systems can lead to better, more energy efficient forms of everyday materials.

"Asegun's project is an excellent example of the type of effort supported by NSF: basic, very complex, and yet potentially disruptive to the engineering practice," said Jose Lage, NSF Thermal Transport Processes program director. "His effort is at the forefront of one of the most exciting new research areas in thermal transport processes, and has already affected our understanding of a very complex engineering phenomenon."

Ultimately, Henry hopes to use the insights he has gained to identify and design materials with unprecedented properties - materials that can transfer heat far more efficiently and potentially even superconducting materials.

"We're at the edge of pushing our community to rethink the problem of thermal conductivity and exploit behaviors to achieve properties that were previously thought to be impossible," he said.

Sonifying Simulations
Scientists typically understand data through graphs and visualizations. But is it possible to use sound to interpret complex information?

Henry believes it is, based on his personal experiences gaining insights from recordings of atomic vibrations. His efforts began when he was trying to understand the results of a simulation of a stretched out polymer chain.

"If you look at the data, it looks like white noise," Henry said. "We decided to sonify the data, and as soon as we listened to it, we could hear the pattern."

Henry, who has a background in music, says this makes sense, given the brain's natural audio processing powers.

"The human ear is better at pattern recognition than the eye is," Henry said. "If you interact with an organ that's better, you can find patterns that aren't obvious."

Ever since, he has been sonifying the vibrations of various materials as a way to explore their significance.

"When you listen to the speaker, the magnet is doing the same motions the atom is doing," he said.

Turning atomic properties into sound may also be an effective way to get students interested in physics and materials science. As part of his NSF CAREER award, Henry has been leading a summer outreach program where African-American and women undergraduates, high school music teachers, and high school students are working to convert the vibrations of atoms into sound files.

They will generate results for the entire periodic table and disseminate their findings through a mobile app that lets you listen to every element.

Individuals will be able to use the mobile app to make music from these sounds, providing a new way for the public to learn and appreciate the beauty of chemistry.

"The approach of using sonification is rather general and could be meaningful for many areas, as it exploits a basic property of human hearing versus sight," Henry said. "Hopefully our application will spark more usage throughout science and engineering."

Research paper


Comment on this article using your Disqus, Facebook, Google or Twitter login.


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

.


Related Links
University of Texas at Austin, Texas Advanced Computing Center
Space Technology News - Applications and Research






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

Previous Report
TECH SPACE
Dressing a metal in various colors
Seoul, South Korea (SPX) Jan 18, 2017
DGIST announced that Professor Kyung-in Jang's research team succeeded in developing a technology that can control various color changes by coating several nanometers of semiconducting materials on a metal substrate through joint research with a research team led by professor Young-min Song of GIST. Professor Kyung-in Jang's research team has succeeded in changing the unique color of metal ... read more


TECH SPACE
French, US astronauts install batteries outside space station

'Hidden Figures' soars in second week atop box office

Russian Astronauts to Hold Terminator Experiment in Space

The dust never settles on the Space Station

TECH SPACE
Ruptured oxidant tank likely cause of Progress accident

Next Cygnus Mission to Station Set for March

Japan aborts mini-rocket mission shortly after liftoff

SpaceX launches, lands rocket for first time since Sept blast

TECH SPACE
Opportunity Continues Its Journey South Along Crater Rim

New Year yields interesting bright soil for Opportunity rover

HI-SEAS Mission V crew preparing to enter Mars simulation habitat

Hues in a Crater Slope

TECH SPACE
China's first cargo spacecraft to leave factory

China launches commercial rocket mission Kuaizhou-1A

China Space Plan to Develop "Strength and Size"

Beijing's space program soars in 2016

TECH SPACE
Iridium-1 NEXT Launched on a Falcon 9

Russia-China Joint Space Studies Center May Be Created in Southeastern Russia

EchoStar 19 positioned in orbital slot

OneWeb announces key funding from SoftBank Group and other investors

TECH SPACE
Glass's off-kilter harmonies

ChemChina 'to file for anti-trust approval in US' for takeover

Breaking the optical bandwidth record of stable pulsed lasers

A toolkit for transformable materials

TECH SPACE
Looking for life in all the right places with the right tool

Could dark streaks in Venusian clouds be microbial life

VLT to Search for Planets in Alpha Centauri System

Hubble detects 'exocomets' taking the plunge into a young star

TECH SPACE
Lowell Observatory to renovate Pluto discovery telescope

Flying observatory makes observations of Jupiter previously only possible from space

How a moon slows the decay of Pluto's atmosphere

York U research identifies icy ridges on Pluto




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






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news 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. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. 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