Immagine
 Trilingual World Observatory: italiano, english, română. GLOBAL NEWS & more... di Redazione
   
 
\\ Home Page : Storico : en - Global Observatory (invert the order)
Di seguito gli interventi pubblicati in questa sezione, in ordine cronologico.
 
 
By Admin (from 17/03/2011 @ 08:00:23, in en - Global Observatory, read 1265 times)

The city of tomorrow takes to the skies in an incredible new concept from Beijing-based MAD Architects. Although its spires may look menacing, the aptly named Superstar is a completely self-sustaining city that is capable of producing all of its own power and food while recycling all of its waste. Conceived as a future-forward update to the contemporary Chinatown, the Superstar will travel the globe, supplying its host cities with energy, commerce, and cultural activities.

Looking suspiciously like a Cylon Base Star from Battlestar Galactica, the utopian Superstar is “a fusion of technology and nature, future and humanity”. MAD Architects conceived of the sparkling modern superstructure as an update to the faded facades and cluttered kitsch of Chinatowns around the globe:

“Superstar: A Mobile China Town is MAD’s response to the redundant and increasingly out-of-date nature of the contemporary Chinatown. Rather than a sloppy patchwork of poor construction and nostalgia, the superstar is a fully integrated, coherent, and above all modern upgrade of the 20th century Chinatown model.”

As a completely self-sustaining city, the Superstar will be capable of housing 15,000 people. It will grow its own food, recycle all of its waste, and produce its own power, even feeding some energy back into its host city’s grid.

The Superstar will also be capable of traveling around the globe, sharing Chinese culture with the cities in which it docks. Inside, one can experience fine Chinese cuisine, purchase quality Chinese goods, and participate in cultural events and celebrations. It will also offer health resorts, sports facilities, drinking-water lakes, and even a digital cemetery to remember those who have passed. According to MAD’s website, the first destination of the super star will be on the outskirts of Rome, where it will provide “an unexpected, ever-changing future imbedded in the Eternal Past”.

While it is questionable whether or not the full-scale Superstar will ever go on tour, visitors and residences in and around Venice are invited to visit a model at the 11th Annual Venice Bienalle.

Source: Inhabitat

 
By Admin (from 19/03/2011 @ 08:00:31, in en - Global Observatory, read 1419 times)

Agave, currently known for its use in the production of alcoholic beverages and fibers, thrives in semi-arid regions where it is less likely to conflict with food and feed production. Agave is a unique feedstock because of its high water use efficiency and ability to survive without water between rainfalls. An article in the current issue of Global Change Biology Bioenergy evaluates the potential of Agave as a sustainable biofuel feedstock.

Scientists found that in 14 independent studies, the yields of two Agave species greatly exceeded the yields of other biofuel feedstocks, such as corn, soybean, sorghum, and wheat. Additionally, even more productive Agave species that have not yet been evaluated exist.

According to bioenergy analyst, Sarah Davis, "We need bioenergy crops that have a low risk of unintended land use change. Biomass from Agave can be harvested as a co-product of tequila production without additional land demands. Also, abandoned Agave plantations in Mexico and Africa that previously supported the natural fiber market could be reclaimed as bioenergy cropland. More research on Agave species is warranted to determine the tolerance ranges of the highest yielding varieties that would be most viable for bioenergy production in semi-arid regions of the world."

Agave is not only an exciting new bioenergy crop, but its economically and environmentally sustainable production could prove to successfully stimulate economies in Africa, Australia, and Mexico, if political and legislative challenges are overcome.

Source: ScienceDaily

 
By Admin (from 20/03/2011 @ 11:00:32, in en - Global Observatory, read 2398 times)

A strain of bacteria found in soil is being studied for its ability to convert waste from a promising alternative fuel into several useful materials, including another alternative fuel.

A graduate student at The University of Alabama in Huntsville is developing biological tools to make products from crude glycerol -- a waste material from the production of biodiesel. The research is being funded by the National Science Foundation.

Disposing of glycerol has been a problem for the biodiesel industry, according to Keerthi Venkataramanan, a student in UAHuntsville's biotechnology Ph.D. program. "Many companies have had problems disposing of it. The glycerol you get as a byproduct isn't pure, so it can't be used in cosmetics or animal feeds. And purifying it costs three times as much as the glycerol is worth."

The volume of glycerol produced is also daunting: About 100,000 gallons of glycerol is produced with every million gallons of biodiesel manufactured from animal fats or vegetable oils. (In 2009 more than 500 million gallons of biodiesel were produced in the U.S. while more than 2.75 billion gallons were produced in Europe.)

Two major American companies "were made to close biodiesel plants in Europe because they couldn't dispose of their crude glycerol," Venkataramanan said. He is working with the Clostidium pasteurianum bacteria, which "eats" glycerol and produces several potentially useful byproducts.

"This strain is found deep in the soil," he said. "It was originally studied for its ability to 'fix' nitrogen from the air."

The bacteria uses glycerol as a carbohydrate source. From that they produce three alcohol byproducts -- butanol, propanediol and ethanol -- plus acetic acid and butyric acid. Butanol is a particularly interesting byproduct.

"Butanol is a big alcohol molecule, twice as big as ethanol," Venkataramanan said. "You can use it as an industrial solvent and it can be used in cars, replacing gasoline with no modifications. It doesn't have some of the problems you have with ethanol, such as rapid evaporation. And ethanol is a two-carbon molecule, but butanol is a four-carbon molecule so its energy value is much higher. In fact, there are plans to use it for jet fuel.

"You can also get butanol from crude oil, but this biological process is less polluting."

In their present form, the bacteria convert about 30 to 35 percent of their gylcerol meals into butanol and another 25 to 30 percent into a chemical used to make plastics.

Venkataramanan is looking at different strategies to improve that yield. He is also studying the bacteria's genes to see if a more productive strain can be bioengineered.

Other groups in the U.S. and abroad are studying a variety of fungi, bacteria and algae for glycerol conversion, but Venkataramanan says his strain has several advantages. Some of the bacteria being studied are dangerous pathogens, while Clostidium pasteurianum "is a completely non-pathogenic strain," he said. "An accidental release is not a big deal. You get it from the soil, so if you spill any you're putting it back in the soil."

Source: ScienceDaily

 

Image
As Human Rights Watch joins Amnesty in calling for the US to explain or desist from the abuse of Bradley Manning, support for Manning has increased around the world. MP Ann Clywd questioned UK Foreign Secretary William Hague regarding Manning's treatment at the meeting of the House of Commons’ Foreign Affairs Committee yesterday (transcript available at UK Friends of Bradley Manning) and she again brought up his treatment today, this time by formally requesting during Business Questions in the Commons that a debate be held on the conditions of Manning's detention. She explicitly compared Manning's treatment to that "meted out" to prisoners at Guantanamo. In his reply, Sir George Young, leader of the House of Commons, did not disavow the comparison to practices at Guantanamo. He said that the concerns conveyed by Clwyd are "widely shared" and agreed that Manning's case was a "suitable subject for debate" in the Commons.

Evidence of international concern is shown in the support for Bradley Manning Day below. For the current conditions of his detainment, and the new charges brought against him, please read Is Bradley Manning being treated like a Guantanamo detainee? For additional WL Central coverage, go here. To read an article by former Australian diplomat Tony Kevin on Manning's detainment, go here. To send an appeal to Cecil B. Wilson, MD, president of the American Medical Association regarding the abuse of medical diagnoses and treatments for torture, written by our correspondent from Holland, go here. For the Amnesty call to action go here.

If you wish to attend a rally and there is none near you, you can start your own by creating an event page somewhere with the date, time and location, and contact us and BradleyManning.org to promote it. Here are ideas to help.

Source: wlcentral.org

 
By Admin (from 22/03/2011 @ 11:00:37, in en - Global Observatory, read 2076 times)

Scientists have created ultra-light and ultra-heavy forms of the element hydrogen, and have investigated their chemical properties.

Donald Fleming, a chemist at the University of British Columbia in Vancouver, Canada, and his colleagues generated two artificial analogues of hydrogen: one with a mass a little over one-tenth that of ordinary hydrogen, and one four times heavier than hydrogen. These pseudo-hydrogens both contain short-lived subatomic particles called muons -- super-heavy versions of the electron.

The researchers tested the behaviour of these new atoms in a chemical reaction called a hydrogen exchange, in which a lone hydrogen atom plucks another from a two-atom hydrogen molecule -- just about the simplest chemical reaction conceivable. In a paper in Science, they report that both the weedy and the bloated hydrogen atoms behave just as quantum theory predicts they should -- which is itself surprising.

The experiment is a "tour de force", says Paul Percival, a muonium chemist at Simon Fraser University in Burnaby, Canada.

"I would never attempt such a difficult task myself," he says, "and when I first saw the proposal I was very doubtful that anything of value could be gained from the Herculean effort. Don Fleming proved me wrong. I doubt if anyone else could have achieved these results."

A normal hydrogen atom contains a single negatively charged electron orbiting a nucleus made of a single positively charged proton. About 0.015% of natural hydrogen consists of the heavy isotope deuterium, in which the nucleus contains a proton and an electrically neutral neutron, and which has a mass twice that of normal hydrogen. And there is a third isotope with a proton and two neutrons: tritium, three times as massive as hydrogen, which is produced in trace quantities by cosmic rays interacting with the atmosphere, but is too dangerously radioactive for use in such experiments.

The chemical behaviour of atoms depends on the number of electrons they have rather than their masses, so the three hydrogen isotopes are chemically almost identical. But the greater mass of the heavy isotopes means that they vibrate at different frequencies, and quantum theory suggests that this will produce a small difference in the rates of their chemical reactions.

To rigorously test that theory, isotopes of hydrogen are needed with greater differences between their masses. Fleming and his colleagues created some, using muons produced by collisions in the TRIUMF particle accelerator in Vancouver.

Muons have many properties similar to electrons, but are more massive. "A muon is an overgrown electron -- an electron on steroids -- with a mass about 200 times that of an electron," says Richard Zare, a physical chemist at Stanford University in California. "But unlike the free electron, the free muon falls apart, with a mean lifetime of about 2.2 microseconds." This meant that the researchers had to work fast to study their pseudo-hydrogen.

To make the ultra-light isotope, they swapped the proton with a positively charged muon, which has just 11% of the mass of a proton. And to make ultra-heavy hydrogen, they replaced one of the electrons in a helium atom with a negative muon.

Helium has two electrons, two protons and two neutrons. But because it is more massive than an electron, the negative muon orbits the nucleus much more closely, masking the positive charge of one of the protons. In effect, the atom becomes a hydrogen-like composite: a 'nucleus' made of the existing two-proton, two-neutron nucleus and the muon, orbited by the remaining electron. It has a mass of a little over four times that of hydrogen.

Fleming and colleagues found that the reaction rates for hydrogen exchange involving these analogues that were calculated from quantum theory were close to those measured experimentally. "This gives confidence in similar theoretical methods applied to more complex systems," says Fleming.

The close match between experiment and theory wasn't necessarily to be expected, because quantum calculations use a simplification called the Born-Oppenheimer approximation, which assumes that the electrons adapt their trajectories instantly to any movement of the nuclei. This is generally true for electrons, which are nearly 2,000 times lighter than protons. But it wasn't obvious that it would hold for muons, which have a tenth of the proton's mass.

"It surprises me at first blush that the theoretical treatments hold up so well," says Zare. "The Born-Oppenheimer approximation is based on the small ratio of the mass of the electron to the mass of the nucleus. Yet suddenly the mass of the electron is increased two-hundred-fold and all seems to be well."

Because the muon has such a short lifetime, extending such studies to more chemically complex systems is very challenging. But Fleming and his colleagues propose now to look at the 'hydrogen' exchange reaction between the super-heavy 'hydrogen' and methane (CH4).

Source: ScientificAmerican

 
By Admin (from 24/03/2011 @ 14:00:31, in en - Global Observatory, read 1413 times)

An engine development company called the Scuderi Group recently announced progress in its effort to build an engine that can reduce fuel consumption by 25 to 36 percent compared to a conventional design. Such an improvement would be roughly equal to a 50 percent increase in fuel economy.

Sal Scuderi, says that nine major automotive companies have signed nondisclosure agreements that allow them access to detailed data about the engine. Scuderi says he is hopeful that at least one of the automakers will sign a licensing deal before the year is over. Historically, major automakers have been reluctant to license engine technology because they prefer to develop the engines themselves as the core technology of their products. But as pressure mounts to meet new fuel-economy regulations, automakers have become more interested in looking at outside technology.

Although Scuderi has built a prototype engine to demonstrate the basic design, the fuel savings figures are based not on the performance of the prototype but on computer simulations that compare the Scuderi engine to the conventional engine in a 2004 Chevrolet Cavalier, a vehicle for which extensive simulation data is publicly available, Scuderi says. Since 2004, automakers have introduced significant improvements to engines, but these generally improve fuel economy in the range of something like 20 percent, compared to the approximately 50 percent improvement the Scuderi simulations show.

There's a big difference, however, between simulation results and data from engines in actual vehicles, says Larry Rinek, a senior consultant with Frost and Sullivan, an analyst firm. "So far things are looking encouraging—but will they really meet the lofty claims?" he says. Automakers should wait to see data from an actual engine installed in a vehicle before they license the technology, he says.

A conventional engine uses a four stroke cycle: air is pulled into the chamber, the air is compressed, fuel is added and a spark ignites the mixture, and finally the combustion gases are forced out of the cylinder. In the Scuderi engine, known as a split-cycle engine, these functions are divided between two adjacent cylinders. One cylinder draws in air and compresses it. The compressed air moves through a tube into a second cylinder, where fuel is added and combustion occurs.

Splitting these functions gives engineers flexibility in how they design and control the engine. In the case of the Scuderi engine, there are two main changes from what happens in a conventional internal-combustion engine. The first is a change to when combustion occurs as the piston moves up and down in the cylinder. The second is the addition of a compressed-air storage tank.

Source: TechnologyReview

 
By Admin (from 26/03/2011 @ 08:00:01, in en - Global Observatory, read 1296 times)

Scientists can now manufacture a synthetic version of the self-healing y substance that mussels use to anchor themselves to rocks in pounding ocean surf and surging tidal basins. A patent is pending on the substance, whose potential applications include use as an adhesive or coating for underwater machinery or in biomedical settings as a surgical adhesive or bonding agent for implants.

Inspiring the invention were the hair-thin holdfast fibers that mussels secrete to stick against rocks in lakes, rivers and oceans. "Everything amazingly just self-assembles underwater in a matter of minutes, which is a process that's still not understood that well," said Niels Holten-Andersen, a postdoctoral scholar with chemistry professor Ka Yee Lee at the University of Chicago.

Holten-Andersen, Lee and an international team of colleagues are publishing the details of their invention this week in the Proceedings of the National Academy of Sciences Early Edition. Holten-Andersen views the evolution of life on Earth as "this beautiful, amazingly huge experiment" in which natural selection has enabled organisms to evolve an optimal use of materials over many millions of years.

"The mussels that live right on the coast where the waves really come crashing in have had to adapt to that environment and build their materials accordingly," he said.

Many existing synthetic coatings involve a compromise between strength and brittleness. Those coatings rely on permanent covalent bonds, a common type of chemical bond that is held together by two atoms that share two or more electrons. The bonds of the mussel-inspired material, however, are linked via metals and exhibit both strength and reversibility.

"These metal bonds are stable, yet if they break, they automatically self-heal without adding any extra energy to the system," Holten-Andersen said.

A key ingredient of the material is a polymer, which consists of long chains of molecules, synthesized by co-author Phillip Messersmith of Northwestern University. When mixed with metal salts at low pH, the polymer appears as a green solution. But the solution immediately transforms into a gel when mixed with sodium hydroxide to change the pH from high acidity to high alkalinity.

"Instead of it being this green solution, it turned into this red, self-healing sticky gel that you can play with, kind of like Silly Putty," he said. Holten-Andersen and his colleagues found that the gel could repair tears within minutes.

"You can change the property of the system by dialing in a pH," said Ka Yee Lee, a professor in chemistry at UChicago and co-author of the PNAS paper. The type of metal ion (an electrically charged atom of, for example. iron, titanium or aluminum) added to the mix provides yet another knob for tuning the material's properties, even at the same pH.

The sticky material that mussels have evolved has inspired an international team of scientists to design a new artificial, self-healing gel that lends itself to underwater applications. The mussels pictured here are attached to a rock on Onetangi Beach of Waiheke Island, New Zealand. Credit: Steve Koppes

"You can tune the stiffness, the strength of the material, by now having two knobs. The question is, what other knobs are out there?" Lee said.
This week's PNAS study reports the most recent in a series of advances related to sticky mussel fibers that various research collaborations have posted in recent years. A 2006 PNAS paper by Haeshin Lee, now of the Korea Advanced Institute of Technology, Northwestern's Phillip Messersmith and UChicago's Norbert Scherer demonstrated an elusive but previously suspected fact. Using atomic-force microscopy, they established that an unusual amino acid called "dopa" was indeed the key ingredient in the adhesive protein mussels use to adhere to rocky surfaces.

Last year in the journal Science, scientists at Germany's Max Planck Institute documented still more details about mussel-fiber chemical bonds. The Max Planck collaboration included Holten-Andersen and Herbert Waite of the University of California, Santa Barbara. Holten-
Andersen began researching the hardness and composition of mussel coatings as a graduate student in Waite's laboratory.

"Our aspiration is to learn some new design principles from nature that we haven't yet actually been using in man-made materials that we can then apply to make man-made materials even better," he said.

Being able to manufacture green materials is another advantage of drawing inspiration from nature. "A lot of our traditional materials are hard to get rid of once we're done with them, whereas nature's materials are obviously made in a way that's environmentally friendly," Holten-Andersen said.

Source: Physorg

 
By Admin (from 29/03/2011 @ 19:13:52, in en - Global Observatory, read 1959 times)

 

MSNBC host Cenk Uygur explains how the National Cancer Institute has recognized several possible medical benefits from marijuana use. This could lead to having marijuana reclassified from a Schedule 1 drug down to a Schedule III drug in which case the government could not crack down on medical marijuana shops.

US National Cancer Institute: "THE POTENTIAL BENEFITS OF MEDICINAL CANNABIS FOR PEOPLE LIVING WITH CANCER INCLUDE ANTIEMETIC EFFECTS, APPETITE STIMULATION, PAIN RELIEF AND IMPROVED SLEEP.

IN THE PRACTICE OF INTEGRATIVE ONCOLOGY, THE HEALTH CARE PROVIDER MAY RECOMMEND MEDICINAL CANNABIS NOT ONLY FOR SYMPTOM MANAGEMENT BUT ALSO FOR ITS POSSIBLE DIRECT ANTITUMOR EFFECT."

 

If someone told you there was a way you could save 2.5 million to 3 million lives a year and simultaneously halt global warming, reduce air and water pollution and develop secure, reliable energy sources – nearly all with existing technology and at costs comparable with what we spend on energy today – why wouldn't you do it?

According to a new study coauthored by Stanford researcher Mark Z. Jacobson, we could accomplish all that by converting the world to clean, renewable energy sources and forgoing fossil fuels.

"Based on our findings, there are no technological or economic barriers to converting the entire world to clean, renewable energy sources," said Jacobson, a professor of civil and environmental engineering. "It is a question of whether we have the societal and political will."

He and Mark Delucchi, of the University of California-Davis, have written a two-part paper in Energy Policy in which they assess the costs, technology and material requirements of converting the planet, using a plan they developed.

The world they envision would run largely on electricity. Their plan calls for using wind, water and solar energy to generate power, with wind and solar power contributing 90 percent of the needed energy.

Geothermal and hydroelectric sources would each contribute about 4 percent in their plan (70 percent of the hydroelectric is already in place), with the remaining 2 percent from wave and tidal power.

Vehicles, ships and trains would be powered by electricity and hydrogen fuel cells. Aircraft would run on liquid hydrogen. Homes would be cooled and warmed with electric heaters – no more natural gas or coal – and water would be preheated by the sun.

Commercial processes would be powered by electricity and hydrogen. In all cases, the hydrogen would be produced from electricity. Thus, wind, water and sun would power the world.

The researchers approached the conversion with the goal that by 2030, all new energy generation would come from wind, water and solar, and by 2050, all pre-existing energy production would be converted as well.

"We wanted to quantify what is necessary in order to replace all the current energy infrastructure – for all purposes – with a really clean and sustainable energy infrastructure within 20 to 40 years," said Jacobson.

One of the benefits of the plan is that it results in a 30 percent reduction in world energy demand since it involves converting combustion processes to electrical or hydrogen fuel cell processes. Electricity is much more efficient than combustion.

That reduction in the amount of power needed, along with the millions of lives saved by the reduction in air pollution from elimination of fossil fuels, would help keep the costs of the conversion down.

"When you actually account for all the costs to society – including medical costs – of the current fuel structure, the costs of our plan are relatively similar to what we have today," Jacobson said.

One of the biggest hurdles with wind and solar energy is that both can be highly variable, which has raised doubts about whether either source is reliable enough to provide "base load" energy, the minimum amount of energy that must be available to customers at any given hour of the day.

Jacobson said that the variability can be overcome.

"The most important thing is to combine renewable energy sources into a bundle," he said. "If you combine them as one commodity and use hydroelectric to fill in gaps, it is a lot easier to match demand."

Wind and solar are complementary, Jacobson said, as wind often peaks at night and sunlight peaks during the day. Using hydroelectric power to fill in the gaps, as it does in our current infrastructure, allows demand to be precisely met by supply in most cases. Other renewable sources such as geothermal and tidal power can also be used to supplement the power from wind and solar sources.

"One of the most promising methods of insuring that supply matches demand is using long-distance transmission to connect widely dispersed sites," said Delucchi. Even if conditions are poor for wind or solar energy generation in one area on a given day, a few hundred miles away the winds could be blowing steadily and the sun shining.

"With a system that is 100 percent wind, water and solar, you can't use normal methods for matching supply and demand. You have to have what people call a supergrid, with long-distance transmission and really good management," he said.

Another method of meeting demand could entail building a bigger renewable-energy infrastructure to match peak hourly demand and use the off-hours excess electricity to produce hydrogen for the industrial and transportation sectors.

Using pricing to control peak demands, a tool that is used today, would also help.

Jacobson and Delucchi assessed whether their plan might run into problems with the amounts of material needed to build all the turbines, solar collectors and other devices.

They found that even materials such as platinum and the rare earth metals, the most obvious potential supply bottlenecks, are available in sufficient amounts. And recycling could effectively extend the supply.

"For solar cells there are different materials, but there are so many choices that if one becomes short, you can switch," Jacobson said. "Major materials for wind energy are concrete and steel and there is no shortage of those."

Jacobson and Delucchi calculated the number of wind turbines needed to implement their plan, as well as the number of solar plants, rooftop photovoltaic cells, geothermal, hydroelectric, tidal and wave-energy installations.

They found that to power 100 percent of the world for all purposes from wind, water and solar resources, the footprint needed is about 0.4 percent of the world's land (mostly solar footprint) and the spacing between installations is another 0.6 percent of the world's land (mostly wind-turbine spacing), Jacobson said.

One of the criticisms of wind power is that wind farms require large amounts of land, due to the spacing required between the windmills to prevent interference of turbulence from one turbine on another.

"Most of the land between wind turbines is available for other uses, such as pasture or farming," Jacobson said. "The actual footprint required by wind turbines to power half the world's energy is less than the area of Manhattan." If half the wind farms were located offshore, a single Manhattan would suffice.

Jacobson said that about 1 percent of the wind turbines required are already in place, and a lesser percentage for solar power.

"This really involves a large scale transformation," he said. "It would require an effort comparable to the Apollo moon project or constructing the interstate highway system."

"But it is possible, without even having to go to new technologies," Jacobson said. "We really need to just decide collectively that this is the direction we want to head as a society."

Source: EurekAlert

 
By Admin (from 03/04/2011 @ 14:00:57, in en - Global Observatory, read 2838 times)

Researchers are developing a new class of "plasmonic metamaterials" as potential building blocks for advanced optical technologies, including ultrapowerful microscopes and computers, improved solar cells, and a possible invisibility cloak.

The new materials could make possible "nanophotonic" devices for numerous applications, said Alexandra Boltasseva, an assistant professor of electrical and computer engineering at Purdue University.

Unlike natural materials, metamaterials may possess an index of refraction less than one or less than zero. Refraction occurs as electromagnetic waves, including light, bend when passing from one material into another. It causes the bent-stick-in-water effect, which occurs when a stick placed in a glass of water appears crooked when viewed from the outside.

Being able to create materials with an index of refraction that's negative or between one and zero promises a range of potential breakthroughs in a new field called transformation optics. However, development of new technologies using metamaterials has been hindered by two major limitations: too much light is "lost," or absorbed by metals such as silver and gold contained in the metamaterials, and the materials need to be more precisely tuned so that they possess the proper index of refraction.

Now, researchers are proposing a new approach to overcome these obstacles. Findings will be detailed in the journal Science. The article was written by Boltasseva and Harry Atwater, Howard Hughes Professor and a professor of applied physics and materials science at the California Institute of Technology.

The researchers are working to replace silver and gold in materials that are created using two options: making semiconductors more metallic by adding metal impurities to them; or adding non-metallic elements to metals, in effect making them less metallic. Examples of these materials include aluminum oxides and titanium nitride, which looks like gold and is used to coat the domes of Russian churches.

Researchers have tested some of the new materials, demonstrating their optical properties and finding that they outperform silver and gold, in work based at the Birck Nanotechnology Center in Purdue's Discovery Park.

Plasmonic metamaterials are promising for various advances, including a possible "hyperlens" that could make optical microscopes 10 times more powerful and able to see objects as small as DNA; advanced sensors; new types of light-harvesting systems for more efficient solar cells; computers and consumer electronics that use light instead of electronic signals to process information; and a cloak of invisibility.

Optical nanophotonic circuits might harness clouds of electrons called "surface plasmons" to manipulate and control the routing of light in devices too tiny for conventional lasers.

Some of the new materials are showing promise in uses involving near-infrared light, the range of the spectrum critical for telecommunications and fiberoptics. Other materials also might work for light in the visible range of the spectrum. The new materials might be tuned so that their refractive index is ideal for specific ranges of the spectrum, allowing their use for particular applications.

Future photonics technologies will revolve around new types of optical transistors, switches and data processors. Conventional computers transmit and process pieces of information in serial form, or one piece at a time. However, future computers may use parallel streams of data, resulting in much faster networks and computers.

Source: Purdue University

 
Ci sono 1558 persone collegate

< agosto 2020 >
L
M
M
G
V
S
D
     
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
           

Titolo
en - Global Observatory (605)
en - Science and Society (594)
en - Video Alert (346)
it - Osservatorio Globale (503)
it - Scienze e Societa (555)
it - Video Alerta (132)
ro - Observator Global (399)
ro - Stiinta si Societate (467)
ro - TV Network (149)
z - Games Giochi Jocuri (68)

Catalogati per mese - Filed by month - Arhivate pe luni:

Gli interventi piů cliccati

Ultimi commenti - Last comments - Ultimele comentarii:
Hi, it's Nathan!Pretty much everyone is using voice search with their Siri/Google/Alexa to ask for services and products now, and next year, it'll be EVERYONE of your customers. Imagine what you are ...
15/01/2019 @ 17:58:25
By Nathan
Now Colorado is one love, I'm already packing suitcases;)
14/01/2018 @ 16:07:36
By Napasechnik
Nice read, I just passed this onto a friend who was doing some research on that. And he just bought me lunch since I found it for him smile So let me rephrase that Thank you for lunch! Whenever you ha...
21/11/2016 @ 09:41:39
By Anonimo


Titolo





09/08/2020 @ 18:51:46
script eseguito in 899 ms