Di seguito gli interventi pubblicati in questa sezione, in ordine cronologico.
The company uses nanostructures for battery materials that, like other recent nanostructures, let the materials deliver the large bursts of power needed for acceleration while maintaining energy storage capacity. But the Wuhe advance also makes the materials easier to work with than similar electrode materials, and as a result, it could cut battery-cell manufacturing costs by 10 percent.
Power structure: A micrograph shows nanoparticles embedded in larger particle of porous carbon.
Battery packs are the most expensive item on electric cars such as the Tesla Roadster and the Nissan Leaf. The cost either makes electric cars too expensive for most people, or it prompts automakers to use small battery packs, which limits the range of the cars.
To reduce battery costs and improve their performance, Wuhe founder Yu-Guo Guo, a professor of chemistry at the Chinese Academy of Sciences in Beijing, has developed new, low-cost ways to improve the properties of lithium-iron phosphate, one of the leading lithium-ion battery electrode materials, and other promising electrode materials.
Ordinarily, the conductivity of lithium-iron phosphate is too low to be useful. The conductivity can be increased by milling it into extremely fine nanoscale powders—as companies such as A123 Systems do. Because the particles are small, electrons or lithium ions—both of which are necessary to create current—can move in and out of them quickly. But this powder is difficult to work with, which raises manufacturing costs.
Guo's solution has been to incorporate iron-phosphate nanoparticles, which are easier to pack closely, and are less likely become airborne, but retain high conductivity. He isn't giving precise details, but he says the technology is based on some of his earlier published work. In one example of that work, he embedded the nanoparticles in larger particles made of porous carbon. The carbon conducts electricity well, and the pores host electrolyte materials that conduct lithium ions well.
Guo says the materials are only 10 to 20 percent more expensive to make than bulk lithium-iron phosphate. But they can deliver about twice as much power as the bulk material, and make twice as much of the energy in lithium-iron phosphate available, roughly doubling the energy storage capacity. Per watt-hour, the materials cost the same as other lithium-iron-phosphate electrode materials, he says. But since the material is easier to work with, it will cut the cost of incorporating the materials into battery cells.
Wuhe, which Guo founded at the end of last year, already has the capacity to produce 300 metric tons of electrode material a year, enough for about 30 million standard lithium-ion battery cells. It also makes battery cells, with the first application being electric bicycles. It can currently make enough cells for roughly 500 electric cars a year.
Jeff Dahn, professor of physics and chemistry at Dalhousie University, says that, based on the company's performance figures, the iron-phosphate batteries will be "very useful" and could perform better than the batteries used now in the electric Chevrolet Volt. And he predicts Wuhe will find a market.
Source: MIT Tech Review
The laser stimulation of optic nerves is the focus of this research to develop a vision prosthesis - perhaps a tiny laser device fitted in a pair of spectacles - much like the cochlear implant for restoring hearing. Swinburne's Applied Optics and Biomedical Engineering Groups are seeking government and philanthropic funding to progress this research using gold nanoparticles to amplify laser light.
These microscopic nanoparticles, fixed to optical nerves and assembled to respond to different laser light wavelength, could become the key to restoring vision to people who have lost their sight through degenerative eye disease.
The researchers are looking for a non-contact method of stimulating nerves and are exploring the use of laser light, rather than the direct electrical stimulation techniques that have become the conventional approach.
Using a very low intensity laser source they are trying to generate the right amount of heat required to elicit a response from nerve cells without damaging them. According to researcher PhD student Chiara Paviolo, the new concept explores the potential for light to deliver far more precise nerve cell stimulation than electrodes. "Electrodes need an electrical current and so they consequently stimulate a group of nerves," Paviolo said. "Light, however, allows us to target individual nerves and this should mean more accurate communication of optical signals - an essential outcome if the information delivered to the brain via a prosthesis is to mean anything useful in terms of shapes, colours, dimensions. You don't just want optical ‘noise'."
The initial goal is to successfully bond the nanoparticles to the nerve and then achieve a response to light heat. Gold nanoparticles are being used because gold is inert, biocompatible and has plasmonic or light-responsive properties. The gold nanoparticles can also be fabricated to respond to different wavelengths, making the interface controllable.
"One of the challenges is to develop nanoparticles that are thermally stable," said Professor of Biointerface Engineering Sally McArthur . "While on one hand heat is necessary, it also has to be limited to avoid damaging cells. Laser heat has long been used in medicine to deliberately kill tissue, but in this instance the opposite result is sought."
To measure and control the heat, the Swinburne team is building a molecular thermal sensor to measure how much heat is produced, so they can then work out how to control it. The team's ultimate ambition for its technology is a prosthesis that in the first instance will restore vision to people who have lost their sight through retinitis pigmentosis or macular degeneration.
"With these diseases the nerve is still alive, making it a strong candidate for a prosthesis," Paviolo said. Paviolo said international interest is already building in the Swinburne project because the concept of using light stimulation combined with nanotechnology is novel.
By scavenging this ambient energy from the air around us, the technique could provide a new way to power networks of wireless sensors, microprocessors and communications chips.
"There is a large amount of electromagnetic energy all around us, but nobody has been able to tap into it," said Manos Tentzeris, a professor in the Georgia Tech School of Electrical and Computer Engineering who is leading the research. "We are using an ultra-wideband antenna that lets us exploit a variety of signals in different frequency ranges, giving us greatly increased power-gathering capability."
Tentzeris and his team are using inkjet printers to combine sensors, antennas and energy scavenging capabilities on paper or flexible polymers. The resulting self powered wireless sensors could be used for chemical, biological, heat and stress sensing for defense and industry; radio frequency identification (RFID) tagging for manufacturing and shipping, and monitoring tasks in many fields including communications and power usage.
Caption: Georgia Tech School of Electrical and Computer Engineering professor Manos Tentzeris holds a sensor (left) and an ultra-broadband spiral antenna for wearable energy-scavenging applications. Both were printed on paper using inkjet technology. - Credit: Georgia Tech Photo: Gary Meek
A presentation on this energy scavenging technology was given July 6 at the IEEE Antennas and Propagation Symposium in Spokane, Wash. The discovery is based on research supported by multiple sponsors, including the National Science Foundation, the Federal Highway Administration and Japan's New Energy and Industrial Technology Development Organization (NEDO).
Communications devices transmit energy in many different frequency ranges, or bands. The team's scavenging devices can capture this energy, convert it from AC to DC, and then store it in capacitors and batteries. The scavenging technology can take advantage presently of frequencies from FM radio to radar, a range spanning 100 megahertz (MHz) to 15 gigahertz (GHz) or higher.
Scavenging experiments utilizing TV bands have already yielded power amounting to hundreds of microwatts, and multi-band systems are expected to generate one milliwatt or more. That amount of power is enough to operate many small electronic devices, including a variety of sensors and microprocessors.
And by combining energy scavenging technology with supercapacitors and cycled operation, the Georgia Tech team expects to power devices requiring above 50 milliwatts. In this approach, energy builds up in a battery-like supercapacitor and is utilized when the required power level is reached.
The researchers have already successfully operated a temperature sensor using electromagnetic energy captured from a television station that was half a kilometer distant. They are preparing another demonstration in which a microprocessor-based microcontroller would be activated simply by holding it in the air.
Exploiting a range of electromagnetic bands increases the dependability of energy scavenging devices, explained Tentzeris, who is also a faculty researcher in the Georgia Electronic Design Center at Georgia Tech. If one frequency range fades temporarily due to usage variations, the system can still exploit other frequencies.
The scavenging device could be used by itself or in tandem with other generating technologies. For example, scavenged energy could assist a solar element to charge a battery during the day. At night, when solar cells don't provide power, scavenged energy would continue to increase the battery charge or would prevent discharging.
Utilizing ambient electromagnetic energy could also provide a form of system backup. If a battery or a solar-collector/battery package failed completely, scavenged energy could allow the system to transmit a wireless distress signal while also potentially maintaining critical functionalities.
The researchers are utilizing inkjet technology to print these energy scavenging devices on paper or flexible paper-like polymers – a technique they already using to produce sensors and antennas. The result would be paper-based wireless sensors that are self powered, low cost and able to function independently almost anywhere.
To print electrical components and circuits, the Georgia Tech researchers use a standard materials inkjet printer. However, they add what Tentzeris calls "a unique in house recipe" containing silver nanoparticles and/or other nanoparticles in an emulsion. This approach enables the team to print not only RF components and circuits, but also novel sensing devices based on such nanomaterials as carbon nanotubes.
When Tentzeris and his research group began inkjet printing of antennas in 2006, the paper-based circuits only functioned at frequencies of 100 or 200 MHz, recalled Rushi Vyas, a graduate student who is working with Tentzeris and graduate student Vasileios Lakafosis on several projects.
"We can now print circuits that are capable of functioning at up to 15 GHz -- 60 GHz if we print on a polymer," Vyas said. "So we have seen a frequency operation improvement of two orders of magnitude."
The researchers believe that self-powered, wireless paper-based sensors will soon be widely available at very low cost. The resulting proliferation of autonomous, inexpensive sensors could be used for applications that include:
Airport security: Airports have both multiple security concerns and vast amounts of available ambient energy from radar and communications sources. These dual factors make them a natural environment for large numbers of wireless sensors capable of detecting potential threats such as explosives or smuggled nuclear material.
Energy savings: Self-powered wireless sensing devices placed throughout a home could provide continuous monitoring of temperature and humidity conditions, leading to highly significant savings on heating and air conditioning costs. And unlike many of today's sensing devices, environmentally friendly paper-based sensors would degrade quickly in landfills.
Structural integrity: Paper or polymer-based sensors could be placed throughout various types of structures to monitor stress. Self powered sensors on buildings, bridges or aircraft could quietly watch for problems, perhaps for many years, and then transmit a signal when they detected an unusual condition.
Food and perishable material storage and quality monitoring: Inexpensive sensors on foods could scan for chemicals that indicate spoilage and send out an early warning if they encountered problems.
Wearable bio-monitoring devices: This emerging wireless technology could become widely used for autonomous observation of patient medical issues.
We had a chance to sit down with Tom Hadfield from Andrea to talk about how this amazing gadget is able to clean the air in your home 1,000 times better than a normal houseplant.
Andrea was invented by French designer Mathieu Lehanneur and Harvard professor David Edwards as a part of a artistic science experiment in 2007. The purifier, which hit the shelves of stores in North America in January of 2010, is able to amplify the air cleaning ability of a plant with the help of a mechanical fan that moves air past the plant’s leaves, through the soil and roots and out through a water tray that collects toxins.
Andrea can work with many a species of house plants and combines stylish design with proven functionality to not only take away toxins from your home but to also add a sense of style. Andrea’s unique multi-stage, all-natural cleaning system ensures a safe and healthy home for your family. “Today people buy air purifiers and then they go out and they buy a vase,” Tom Hadfield told us. “We think the future of indoor air purification might be somewhere in between those two.”
Source: InHabitat - via: Zeitnews.org
Gli esperti di marketing definiscono "redemption" il tasso di risposta del pubblico a un certo stimolo: se per esempio vengono distribuiti 100 buoni sconto per l'acquisto un prodotto a prezzo ridotto e 40 di questi vengono effettivamente utilizzati, la redemption della campagna promozionale è del 40%.
Ebbene, Harold Hackett, un signore canadese appassionato di esperimenti socio culturali, nell'epoca dei social network e dei canali televisivi interattivi è riuscito a dimostrare che lo strumento di comunicazione più efficace è ancora il messaggio nella bottiglia abbandonato tra le onde.
Message in a bottle...
A partire dal maggio del 1996 Hacket ha liberato nelle acque dell'Atlantico oltre 4800 bottiglie di plastica contenenti un messaggio e da allora ha ottenuto ben 3100 risposte da tutto il mondo. Ora ha amici di penna in Africa, Russia, Regno Unito, Scozia, Francia, Bahamas...
E per rendere il suo esperimento assolutamente anologico Hacket non ha inserito nei suoi messaggi nè il suo numero di telefono nè il suo indirizzo e-mail, ma solo quello postale. In questo modo si è assicurato che tutte le risposte gli arrivassero per lettera.
Ogni bottiglia è numerata, così Harold sa a quale dei suoi messaggi si riferisce la risposta: alcune bottiglie sono state in balia delle onde per più di 13 anni prima di essere trovate da qualcuno.
An ambitious University of Nevada, Reno project to understand and characterize geothermal potential at nearly 500 sites throughout the Great Basin is yielding a bounty of information for the geothermal industry to use in developing resources in Nevada, according to a report to the U.S. Department of Energy.
The project, based in the University's Bureau of Mines and Geology in the College of Science, is funded by a $1 million DOE grant from the American Recovery and Reinvestment Act of 2009. It has reached the one-year mark and is entering phase two, when five or six of the 250 identified potentially viable geothermal sites will be studied in more detail. Some of the studied sites will even have 3-D imaging to help those in the industry better understand geothermal processes and identify where to drill for the hot fluids.
The research aims to provide a catalogue of favorable structural elements, such as the pattern of faulting and models for geothermal systems and site-specific targeting using innovative techniques for fault analysis. The project will enhance exploration methodologies and reduce the risk of drilling nonproductive wells.
Jim Faulds, geologist and research professor at the University of Nevada, Reno's Bureau of Mines and Geology, lectures his geothermal exploration class in April at the Fly Ranch Geyser north of Gerlach, Nev. (Credit: Photo courtesy of the University of Nevada, Reno.)
Jim Faulds, principal investigator for the project, geologist and research professor at the University of Nevada, Reno, has a team of six researchers and several graduate students working with him on various aspects of the project.
"Of the 463 geothermal sites to study, we've studied and characterized more than 250 in the past year, either using existing records or on-site analyses," Faulds said. "We'll continue to study more of the sites so we can develop better methods and tools for geothermal exploration. Most, about two-thirds, of the geothermal resources in the Great Basin are blind -- that is, there are no surface expressions, such as hot springs, to indicate what's perhaps 1,500 feet below the surface."
Better characterization of known geothermal systems is critical for new discoveries, targeting drilling sites and development, Faulds said. The success of modeling sites for exploration is limited without basic knowledge of which fault and fracture patterns, stress conditions, and stratigraphic intervals are most conducive to hosting geothermal reservoirs.
"The geothermal industry doesn't have the same depth of knowledge for geothermal exploration as the mineral and oil industries," he said. "Mineral and oil companies conducted extensive research years ago that helps them to characterize favorable settings and determine where to drill. With geothermal, it's studies like this that will enhance understanding of what controls hot fluids in the Earth's crust and thus provide an exploration basis for industry to use in discovering and developing resources."
Faulds and his team have defined a spectrum of favorable structural settings for geothermal systems in the Great Basin and completed a preliminary catalogue that interprets the structural setting of most its geothermal systems.
"This is the first attempt to broadly characterize and catalogue Great Basin geothermal systems in this way," he said.
In addition, Faulds has developed and taught a geothermal exploration class, published many papers on his work and presented his work at many conferences, including the World Geothermal Congress in Bali, Indonesia and the GEONZ2010 Geoscience-Geothermal Conference in Auckland, New Zealand.
Faulds also presented information from his study at a session of the National Geothermal Academy at the University of Nevada, Reno.
"We want to help the industry achieve acceptable levels of site-selection risk ahead of expensive drilling," he said. "This study costs only $1 million, but it could cost a company several million dollars for drilling at a single prospect in the hopes that they hit a good hot well. Our research will provide the baseline studies that are absolutely needed if Nevada is going to become the Saudi Arabia of geothermal."
Source: Science Daily
Most people may think the speed of light is constant, but this is only the case in a vacuum, such as space, where it travels at 671million mph.
However, when it travels through different substances, such as water or solids, its speed is reduced, with different wavelengths (colours) travelling at different speeds.
The green laser is shown as it leaves the ruby crystal.
In addition, it has also been observed, but is not widely appreciated, that light can be dragged when it travels through a moving substance, such as glass, air or water – a phenomenon first predicted by Augustin-Jean Fresnel in 1818 and observed a hundred years later.
Prof. Miles Padgett in the Optics Group in the School of Physics & Astronomy, said: “The speed of light is a constant only in vacuum . When light travels through glass, movement of the glass drags the light with it too.
“Spinning a window as fast as you could is predicted to rotate the image of the world behind it ever so slightly. This rotation would be about a millionth of a degree and imperceptible to the human eye.”
In research detailed in the latest edition of the journal Science, researchers Dr Sonja Franke-Arnold, Dr Graham Gibson and Prof Padgett, in collaboration with their colleague Professor Robert Boyd at the Universities of Ottowa and Rochester, took a different approach and set up an experiment: shining a primitive image made up of the elliptical profile of a green laser through a ruby rod spinning on its axis at up to 3,000 rpm.
Once the light enters the ruby, its speed is slowed down to around the speed of sound (approximately 741mph) and the spinning motion of the rod drags the light with it, resulting in the image being rotated by almost five degrees: large enough to see with the naked eye.
Dr Franke-Arnold, who came up with the idea of using slow light in ruby to observe the photon drag, said: “We mainly wanted to demonstrate a fundamental optical principle, but this work has possible applications too.
“Images are information and the ability to store their intensity and phase is an important step to the optical storage and processing of quantum information, potentially achieving what no classical computer can ever match.
“The option to rotate an image by a set arbitrary angle presents a new way to code information, a possibility not accessed by any image coding protocol so far.”
Cei doi judecatori de la Inalta Curte din Londra responsabili de acest dosar au respins argumentele apararii potrivit carora cererea de extradare a australianului in varsta de 40 de ani este "injusta si contrara legii".
Julian Assange, suspectat in Suedia de viol si agresiune sexuala, a fost arestat in decembrie in Marea Britanie.
O prima instanta britanica a aprobat, in februarie, extradarea lui Assange, insa avocatii acestuia au declansat o procedura complexa de apel.
Fondatorul WikiLeaks, consemnat la domiciliu in Marea Britanie in asteptarea deciziei judecatoresti, locuieste la conacul unui prieten, nu departe de Londra.
Site-ul WikiLeaks a inceput sa publice in noiembrie 2010 mii de telegrame diplomatice americane, site-ul si fondatorul sau atragand critici dure din partea administratiei de la Washington.
Într-o biografie neautorizata publicata in septembrie, Julian Assange dezminte inca o data acuzatiile de viol formulate in Suedia, denuntand o manipulare politica. "Aceste doua femei au avut cu mine relatii sexuale deplin consimtite", afirma el.
All'inizio, due anni fa, c'era solo Cagliari, poi si è aggiunto Calenzano in provincia di Firenze, seguito da Genova, Castelfranco Emilia (Mo), Civita Castellana, Napoli, Torino e, più recentemente, Padova, Casalecchio di Reno (Bo), Castel del Piano in provincia di Grosseto. La lista dei comuni che ha istituito un registro del testamento biologico si allunga sempre più: ora se ne contano ottanta e hanno deciso di unirsi nella "Lega degli enti locali per il registro delle dichiarazioni anticipate di trattamento".
L'Associazione Luca Coscioni, promotrice della campagna iniziata nel 2009 dopo la morte di Eluana Englaro, può ritenersi soddisfatta. La mappa dell'Italia, consultabile on-line, è affollata di bandierine verdi che indicano i piccoli o grandi centri dove è possibile depositare le proprie volontà sul fine vita. Tra questi manca proprio Lecco, paese natale di Eluana Englaro, che ha rimandato al mittente con 28 voti contrari, 7 favorevoli e 4 astenuti, la proposta dell'istituzione del registro per le volontà anticipate di trattamento.
Tra gli obiettivi della neonata associazione di comuni vi è quello di "tutelare il diritto all'autodeterminazione dei cittadini anche attraverso gli adeguati strumenti giudiziari e ad individuare i principi giuridici che permettono alle amministrazioni locali di intervenire, nonostante controversie interpretative anche da parte ministeriale". Il documento della Lega dei comuni si riferisce a una circolare del 2010, firmata dai ministri della Salute Ferruccio Fazio, del Welfare Maurizio Sacconi e degli Interni Roberto Maroni, che liquidava l'iniziativa dei comuni come priva di "qualunque efficacia giuridica".
L'ANCI (Associazione Nazionale Comuni Italiani), da parte sua , ha sempre difeso il valore legale dei registri. Ma, in questo momento, la questione passa forse in secondo piano: la campagna dell'Associazione Luca Coscioni, così come le altre iniziative parallele (il videotestamento, la petizione al parlamento su testamento biologico ed eutanasia) serve innanzitutto per affermare il dissenso al DDL Calabrò che è in attesa di venire licenziato dal Senato, dopo gli emendamenti introdotti alla Camera il 12 luglio scorso.
The study, which appears in Science, reveals a unique pattern of brain activity when false memories are formed – one that hints at a surprising connection between our social selves and memory.
The experiment, conducted by Prof. Yadin Dudai and research student Micah Edelson of the Institute's Neurobiology Department with Prof. Raymond Dolan and Dr. Tali Sharot of University College London, took place in four stages. In the first, volunteers watched a documentary film in small groups. Three days later, they returned to the lab individually to take a memory test, answering questions about the film. They were also asked how confident they were in their answers.
They were later invited back to the lab to retake the test while being scanned in a functional MRI (fMRI) that revealed their brain activity. This time, the subjects were also given a "lifeline": the supposed answers of the others in their film viewing group (along with social-media-style photos). Planted among these were false answers to questions the volunteers had previously answered correctly and confidently. The participants conformed to the group on these "planted" responses, giving incorrect answers nearly 70% of the time.
But were they simply conforming to perceived social demands, or had their memory of the film actually undergone a change? To find out, the researchers invited the subjects back to the lab to take the memory test once again, telling them that the answers they had previously been fed were not those of their fellow film watchers, but random computer generations. Some of the responses reverted back to the original, correct ones, but close to half remained erroneous, implying that the subjects were relying on false memories implanted in the earlier session.
An analysis of the fMRI data showed differences in brain activity between the persistent false memories and the temporary errors of social compliance. The most outstanding feature of the false memories was a strong co-activation and connectivity between two brain areas: the hippocampus and the amygdala. The hippocampus is known to play a role in long-term memory formation, while the amygdala, sometimes known as the emotion center of the brain, plays a role in social interaction. The scientists think that the amygdala may act as a gateway connecting the social and memory processing parts of our brain; its "stamp" may be needed for some types of memories, giving them approval to be uploaded to the memory banks. Thus social reinforcement could act on the amygdala to persuade our brains to replace a strong memory with a false one.