nanotube

Nanotube

Carbon nanotube (31)
Metallic nanotube (2)
Nanotube (25)

Synopsis: Nanotechnology: Nanotechnology generale: Nanostructures: Nanotube:

texte_agro-tech\futurity_sci_tech 00717.txt

#DNA motor uses arms to walk across a nanotube Purdue University rightoriginal Studyposted by Emil Venere-Purdue on December 19 2013engineers made a motor out of DNA

and then used it to move nanoparticles of cadmium disulfide along the length of a nanotube.

As it moves along a carbon-nanotube track it continuously harvests energy from strands of RNA molecules vital to a variety of roles in living cells

and viruses. ur motors extract chemical energy from RNA molecules decorated on the nanotubes and use that energy to fuel autonomous walking along the carbon nanotube trackchoi says.

The core is made of an enzyme that cleaves off part of a strand of RNA. After cleavage the upper DNA arm moves forward binding with the next strand of RNA

The process repeats until reaching the end of the nanotube track. The researchers combined two fluorescent imaging systems to document the motor s movement one in the visible spectrum and the other in the near-infrared range.

and the nanotubes are fluorescent in the near-infrared. The motor took about 20 hours to reach the end of the nanotube which was several microns long

but the process might be sped up by changing temperature and ph a measure of acidity.

texte_agro-tech\futurity_sci_tech 00893.txt

#Does this carbon nanotube computer spell the end for silicon? Stanford university rightoriginal Studyposted by Tom Abate-Stanford on September 27 2013engineers have built a basic computer using carbon nanotubes a success that points to a potentially faster more efficient alternative to silicon chips.

The achievement is reported in an article on the cover of the journal Nature. eople have been talking about a new era of carbon nanotube electronics moving beyond siliconsays Subhasish Mitra an electrical engineer

Here is the proof. xperts say the achievement will galvanize efforts to find successors to silicon chips which could soon encounter physical limits that might prevent them from delivering smaller faster cheaper electronic devices. arbon nanotubes CNTS have long been considered as a potential successor to the silicon transistorsays Professor

But until now it hasn t been clear that CNTS a semiconductor material could fulfill those expectations. here is no question that this will get the attention of researchers in the semiconductor community

But a bedeviling array of imperfections in these carbon nanotubes has frustrated long efforts to build complex circuits using CNTS.

team has made to this worldwide effort. irst they put in place a process for fabricating CNT-based circuitsde Micheli says. econd they built a simple

but effective circuit that shows that computation is doable using CNTS. s Mitra says: t s not just about the CNT COMPUTER.

It s about a change in directions that shows you can build something real using nanotechnologies that move beyond silicon

He called the Stanford work major benchmarkin moving CNTS toward practical use. CNTS are long chains of carbon atoms that are extremely efficient at conducting and controlling electricity.

They are so thinâ##thousands of CNTS could fit side by side in a human hairâ##that it takes very little energy to switch them off according to Wong a co-author of the paper. hink of it as stepping on a garden hosewong explains. he thinner the hose the easier it is to shut off the flow. n theory this combination

of efficient conductivity and low-power switching make carbon nanotubes excellent candidates to serve as electronic transistors. NTS could take us at least an order of magnitude in performance beyond where you can project silicon could take uswong said.

First CNTS do not necessarily grow in neat parallel lines as chipmakers would like. Over time researchers have devised tricks to grow 99.5 percent of CNTS in straight lines.

But with billions of nanotubes on a chip even a tiny degree of misaligned tubes could cause errors

so that problem remained. A second type of imperfection has stymied also CNT technology. Depending on how the CNTS grow a fraction of these carbon nanotubes can end up behaving like metallic wires that always conduct electricity instead of acting like semiconductors that can be switched off.

Since mass production is the eventual goal researchers had to find ways to deal with misaligned

and/or metallic CNTS without having to hunt for them like needles in a haystack. e needed a way to design circuits without having to look for imperfections

or even know where they weremitra says. The Stanford paper describes a two-pronged approach that the authors call an mperfection-immune design. o eliminate the wire-like

or metallic nanotubes the Stanford team switched off all the good CNTS. Then they pumped the semiconductor circuit full of electricity.

All of that electricity concentrated in the metallic nanotubes which grew so hot that they burned up

This sophisticated technique eliminated the metallic CNTS in the circuit. Bypassing the misaligned nanotubes required even greater subtlety.

The Stanford researchers created a powerful algorithm that maps out a circuit layout that is guaranteed to work no matter

whether or where CNTS might be askew. his imperfections-immune design technique makes this discovery truly exemplarysays Sankar Basu a program director at the National Science Foundation.

Their CNT COMPUTER performed tasks such as counting and number sorting. It runs a basic operating system that allows it to swap between these processes.

In a demonstration of its potential the researchers also showed that the CNT COMPUTER could run MIPS a commercial instruction set developed in the early 1980s by then Stanford engineering professor and now university President John Hennessy.

Though it could take years to mature the Stanford approach points toward the possibility of industrial-scale production of carbon nanotube semiconductors according to Naresh Shanbhag a professor at the University of Illinois at Urbana-Champaign

and director of SONIC a consortium of next-generation chip design research. he Wong/Mitra paper demonstrates the promise of CNTS in designing complex computing systemsshanbhag says adding that this will motivate researchers elsewhere toward greater efforts in chip design

and a world leader in CNT research. The National Science Foundation SONIC the Stanford Graduate Fellowship and the Hertz Foundation Fellowship funded the work.

texte_agro-tech\impactlab_2011 01743.txt

But the sensors aren just useful for explosives the researchers found that the coated nanotubes can also detect two pesticides that contain nitro-aromatic compounds.

texte_agro-tech\newsoffice 00415.txt

Using another type of carbon nanotube, they also modified plants to detect the gas nitric oxide. Together

photosynthetic activity measured by the rate of electron flow through the thylakoid membranes was 49 percent greater than that in isolated chloroplasts without embedded nanotubes.

the nanotubes moved into the chloroplast and boosted photosynthetic electron flow by about 30 percent.

Strano lab has developed previously carbon nanotube sensors for many different chemicals, including hydrogen peroxide, the explosive TNT, and the nerve gas sarin.

When the target molecule binds to a polymer wrapped around the nanotube, it alters the tube fluorescence. e could someday use these carbon nanotubes to make sensors that detect in real time, at the single-particle level,

texte_agro-tech\phys_org 00466.txt

and nanotubes using any method they like and use the shrinking action to compact them into a higher density."

texte_agro-tech\R_www.nanotech-now.com 2015 01274.txt

Rice university researchers model graphene/nanotube hybrids to test properties September 14th, 2015coming out September 14th, 2015nano in food and agriculture:

Understanding motions of thin layers may help design solar cells, electronics and catalysts of the future September 10th, 2015realizing carbon nanotube integrated circuits:

Encapsulation layers keep carbon nanotube transistors stable in open air September 8th, 2015new nanomaterial maintains conductivity in three dimensions:

International team seamlessly bonds CNTS and graphene September 5th, 2015phagraphene, a'relative'of graphene, discovered September 2nd, 2015chip Technology Pillared graphene gains strength:

Rice university researchers model graphene/nanotube hybrids to test properties September 14th, 2015an even more versatile optical chip:

Rice university researchers model graphene/nanotube hybrids to test properties September 14th, 2015coming out September 14th, 2015nano in food and agriculture:

texte_agro-tech\R_www.nanotech-now.com 2015 01275.txt

Rice university researchers model graphene/nanotube hybrids to test properties September 14th, 2015coming out September 14th, 2015nano in food and agriculture:

Rice university researchers model graphene/nanotube hybrids to test properties September 14th, 2015an even more versatile optical chip:

Rice university researchers model graphene/nanotube hybrids to test properties September 14th, 2015coming out September 14th, 2015nano in food and agriculture:

texte_agro-tech\R_www.nanowerk.com 2015 0000479.txt

Nagoya University and the JST-ERATO Itami Molecular Nanocarbon Project have developed a bulky iridium catalyst that selectively directs a boron moiety to the opposite side of mono-substituted benzene derivatives.

< Back - Next >