Category Technology/Electronics

Researchers Resolve a Problem holding back a Technological Revolution: purifying CNTs

Artistic rendition of a metallic carbon nanotube being pulled into solution, in analogy to the work described by the Adronov group.

Artistic rendition of a metallic carbon nanotube being pulled into solution, in analogy to the work described by the Adronov group.

Imagine an electronic newspaper that you could roll up and spill your coffee on, even as it updated itself before your eyes. It’s an example of the technological revolution that has been waiting to happen. Researchers at McMaster University have developed a new way to purify carbon nanotubes – smaller, flexible semiconductors expected to replace silicon within computer chips and a wide array of electronics. “Once we have a reliable source of pure nanotubes that are not very expensive, a lot can happen very quickly,” says Prof Adronov.

A major problem standing in the way of the new technology, however, has been untangling metallic and semiconducting carbon nano...

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New Residential Water Heater Concept promises High Efficiency, Lower Cost

A new of gas-fired heat pump water heaters, based on a novel semi-open sorption concept, could replace the evaporator in a traditional devices with a vapor-permeable membrane that more efficiently absorbs and transfers heat for residential applications. Credit: ORNL

A new class of gas-fired heat pump water heaters, based on a novel semi-open sorption concept, could replace the evaporator in a traditional devices with a vapor-permeable membrane that more efficiently absorbs and transfers heat for residential applications. Credit: ORNL

Scientists from Dept of Energy’s Oak Ridge National Laboratory and the University of Florida has developed a novel method that could yield lower-cost, higher-efficiency systems for water heating in residential buildings. The theory behind the newly termed “semi-open” natural gas-fired design reduces the cost and complexity of traditional closed gas-fired systems by streamlining, and even eliminating, certain components.

“When applied, the new concept could result in better than 100% energy efficiency, because the system d...

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Nanoribbons in Solutions Mimic Nature

The tip of an atomic force microscope on a cantilevered arm is used to pull a graphene nanoribbon the same way it would be used to pull apart a protein or a strand of DNA in a Rice University lab. The microscope can be used to measure properties like rigidity in a material as it's manipulated by the tip.

The tip of an atomic force microscope on a cantilevered arm is used to pull a graphene nanoribbon the same way it would be used to pull apart a protein or a strand of DNA in a Rice University lab. The microscope can be used to measure properties like rigidity in a material as it’s manipulated by the tip. Courtesy of the Kiang Research Group

Graphene nanoribbons (GNRs) bend and twist easily in solution, making them adaptable for biological uses like DNA analysis, drug delivery and biomimetic applications, according to scientists at Rice University. GNR’s can be thousands of times longer than they are wide. They can be produced in bulk by chemically “unzipping” carbon nanotubes, a process invented by Rice chemist and co-author James Tour and his lab.

Their size means they can operate on th...

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Researchers demonstrate Acoustic Levitation of a Large Sphere

levitation

Acoustic levitation of a polystyrene sphere, the first spherical object to be acoustically levitated that is larger than the acoustic wavelength. Credit: Andrade et al. ©2016 AIP Publishing

In a new study, researchers have demonstrated the acoustic levitation of a 50-mm (2″) solid polystyrene sphere using ultrasound—acoustic waves that are above the frequency of human hearing. It is one of the first times that an object larger than the wavelength of the acoustic wave has been acoustically levitated. Previously, this has been achieved only for a few specific cases, such as wire-like and planar objects. In the new study, the levitated sphere is 3.6 times larger than the 14-mm acoustic wavelength used here.

“Acoustic levitation of small particles at the acoustic pressure nodes of a standin...

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