Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. Earth Science News .




DISASTER MANAGEMENT
Research Opens Doors To UV Disinfection Using LED Technology
by Staff Writers
Raleigh, NC (SPX) May 24, 2012


Researchers found that trace carbon atoms in the substrate of the aluminum nitride semiconductors block key wavelengths of ultraviolet light.

Research from North Carolina State University will allow the development of energy-efficient LED devices that use ultraviolet (UV) light to kill pathogens such as bacteria and viruses. The technology has a wide array of applications ranging from drinking-water treatment to sterilizing surgical tools.

"UV treatment utilizing LEDs would be more cost-effective, energy efficient and longer lasting," says Dr. Ramon Collazo, an assistant professor of materials science and engineering at NC State and lead author of a paper describing the research. "Our work would also allow for the development of robust and portable water-treatment technologies for use in developing countries."

LEDs utilize aluminum nitride (AlN) as a semiconductor, because the material can handle a lot of power and create light in a wide spectrum of colors, particularly in the UV range. However, technologies that use AlN LEDs to create UV light have been severely limited because the substrates that served as the foundation for these semiconductors absorbed wavelengths of UV light that are crucial to applications in sterilization and water treatment technologies.

A team of researchers from North Carolina and Japan has developed a solution to the problem. Using computer simulation, they determined that trace carbon atoms in the crystalline structure of the AlN substrate were responsible for absorbing most of the relevant UV light. By eliminating the carbon in the substrate, the team was able to significantly improve the amount of UV light that can pass through the substrate at the desired wavelengths.

"Once we identified the problem, it was relatively easy and inexpensive to address," says Dr. Zlatko Sitar, Kobe Steel Distinguished Professor of Materials Science and Engineering at NC State and co-author of the paper.

Commercial technologies incorporating this research are currently being developed by HexaTech Inc., a spin-off company from NC State.

"This is a problem that's been around for more than 30 years, and we were able to solve it by integrating advanced computation, materials synthesis and characterization," says Dr. Doug Irving, assistant professor of materials science and engineering at NC State and co-author of the paper. "I think we'll see more work in this vein as the Materials Genome Initiative moves forward, and that this approach will accelerate the development of new materials and related technologies."

The paper, "On the origin of the 265 nm absorption band in AlN bulk crystals," is published online in Applied Physics Letters. Co-authors include Benjamin Gaddy, Zachary Bryan, Ronny Kirste and Marc Hoffman from NC State, as well as researchers from HexaTech Inc., Tokyo University of Agriculture and Technology, and the Tokuyama Corporation. The research was supported with funding from the U.S. Department of Defense.

.


Related Links
North Carolina State University
Bringing Order To A World Of Disasters
A world of storm and tempest
When the Earth Quakes






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





DISASTER MANAGEMENT
Italy quake survivors urged to return home
Rome (AFP) May 23, 2012
Authorities on Wednesday urged survivors of a deadly earthquake in northeastern Italy to return home if their property was not damaged in the disaster, despite fresh aftershocks. Arturo Gherardi, the civil protection chief in the worst-hit town of Finale Emilia, said that it was time for residents to go back to their homes provided they emerged unscathed from Sunday morning's quake. "The ... read more


DISASTER MANAGEMENT
Italy quake survivors urged to return home

Research Opens Doors To UV Disinfection Using LED Technology

Fukushima radiation mostly within accepted levels: WHO

Bulgaria warned over quake response

DISASTER MANAGEMENT
Laser scan at full speed

Facebook makes mobile move after IPO flop

7-inch Google tablet said imminent

How ion bombardment reshapes metal surfaces

DISASTER MANAGEMENT
Swiss ultralight trikes used to explore Lake Baikal

Marine reserves boost fish: Australian study

New speaker can recreate dolphin sounds

Finding fingerprints in sea level rise

DISASTER MANAGEMENT
Illuminating the Ancient History of Circumarctic Peoples

Toxic mercury, accumulating in the Arctic, springs from a hidden source

Russia's Antarctic probes to be tested in Ladoga Lake

Scientists discover new site of potential instability in West Antarctic Ice Sheet

DISASTER MANAGEMENT
Blossom end rot plummets in Purdue-developed transgenic tomato

Where bees are, there will be honey even pre-historic

Financial tool considered climate change uncertainty to select land for conservation

How plants chill out

DISASTER MANAGEMENT
Earthquake rattles New Zealand's Christchurch

Japan tsunami bones to wash up in US: oceanographer

Hurricane Bud forms off southwest Mexico: US monitors

Alaskan ecologists see surge in Japan tsunami debris

DISASTER MANAGEMENT
G. Bissau army to return to barracks

Somali, AU troops close in on Islamist stronghold of Afgoye

45 Chinese arrested for illegal trading in Nigeria: official

Army, mutineers clash near DR Congo rare gorilla park

DISASTER MANAGEMENT
Chimpanzees have human-like personalities

Urban landscape's power to hurt or heal

Anthropologists discover earliest form of wall art

Evolution's gift may also be at the root of a form of autism




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