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Next-generation soap!

Waterborne disease kills three children every minute. This handheld device, called Kopper – which costs only $A2.50 to make – could prevent some of these deaths.

Designed by Balin Lee, a graduate of the University of Western Sydney, it removes 99.99 per cent of all parasites, viruses and bacteria found in contaminated water.

The device works by squeezing water through a microfilter, removing anything larger than 0.1 micrometre, which includes Escherichia coli and Giardia. It then fries anything left with electrolysis, which splits the oxygen and hydrogen molecules, removing tinier pathogens in the water.

Kopper is powered by piezoelectric generators that convert kinetic energy into an electrical current: powering the device requires only a few shakes.

(Image: Balin Lee/SRD Change)

Slum reshaping, breathing buildings and next-generation soap are just some of the ideas on display at the annual SRD Change Exhibition in Sydney, Australia. The show flaunts the best in sustainable and environmental design aiming "to create products and services that focus on tangible and positive benefits for society in every possible aspect", says Greg Campbell, the SRD Change curator.


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Spintronics — also known as magnetoelectronics — may replace electronics as the medium of choice for computer memory. The discovery of a mechanism that produces permanent magnets at room temperature, without any external influence, may soon improve the design of spintronic devices. Takumi Ohtsuki from the RIKEN SPring-8 Center, Harima and his colleagues in Japan, made the discovery in a class of material called a dilute ferromagnetic oxide.

Mediating magnetism

A representation of a thin film of Co:TiO2 in which ferromagnetism arises because titanium 3d electrons (green) travel around the material aligning the spin of cobalt atoms (pink) so that they all point in the same direction. The blue and brown spheres correspond to titanium and oxygen atoms, respectively. Credit: 2011 Takumi Ohtsuki

Ferromagnetism is the mechanism responsible for making some materials magnetic without any external influence. In a ferromagnet, the axes about which a majority of the electrons spin are all parallel, but the underlying cause for this alignment is not always clear. A dilute ferromagnetic oxide is an oxide material doped with a small amount of a transition metal, which represents a marriage between magnetic materials and those used in electronics. Crucially, and unlike the ferromagnetic-semiconductors, dilute ferromagnetic oxides remain in a ferromagnetic state at room temperature.

Some materials have ferromagnetic constituents but exhibit no magnetism. However, some ferromagnets consist of substances that, on their own, are nonmagnetic. A full understanding of this enigma is vital for designing efficient spintronic devices and requires determining which electrons, or other type of charge carrier in a material, mediate the ferromagnetism. To resolve this question in dilute ferromagnetic oxides, Ohtsuki and his co-workers examined one commonly used example: cobalt-doped titanium dioxide (Co:TiO2). “Several mechanisms have been suggested for the origin of ferromagnetism in Co:TiO2, but no firm conclusion has been established,” says Ohtsuki.

The researchers used a powerful material characterization technique known as x-ray photoemission spectroscopy. A beam of x-rays, in this case from the SPring-8 synchrotron radiation facility, excited electrons from the sample of Co:TiO2. “The number of excited electrons versus their kinetic energies provided detailed information about the atomic composition and electronic state of the material,” explains Ohtsuki.

Ohtsuki and his team established that ferromagnetism is mediated by the electrons in the third shell—so-called 3d electrons—of the titanium ions (Fig. 1), a mechanism that has never been considered as a possibility by scientists before. The titanium 3d electrons align the spin of the cobalt atoms as they travel through the material.

The team’s discovery enhances the likelihood that dilute ferromagnetic oxides will be used as spintronic devices. “Our results have proven that magnetism and conductivity are correlated in Co:TiO2 thin films,” explains Ohtsuki. “This could make them applicable to magnetic random access memory (MRAM) or spin transistors.”

Source: PhysOrg

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In the arid Namib Desert on the west coast of Africa, one type of beetle has found a distinctive way of surviving. When the morning fog rolls in, the Stenocara gracilipes species, also known as the Namib Beetle, collects water droplets on its bumpy back, then lets the moisture roll down into its mouth, allowing it to drink in an area devoid of flowing water.

What nature has developed, Shreerang Chhatre wants to refine, to help the world's poor. Chhatre is an engineer and aspiring entrepreneur at MIT who works on fog harvesting, the deployment of devices that, like the beetle, attract water droplets and corral the runoff. This way, poor villagers could collect clean water near their homes, instead of spending hours carrying water from distant wells or streams. In pursuing the technical and financial sides of his project, Chhatre is simultaneously a doctoral candidate in chemical engineering at MIT; an MBA student at the MIT Sloan School of Management; and a fellow at MIT's Legatum Center for Development and Entrepreneurship.

Access to water is a pressing global issue: the World Health Organization and UNICEF estimate that nearly 900 million people worldwide live without safe drinking water. The burden of finding and transporting that water falls heavily on women and children. "As a middle-class person, I think it's terrible that the poor have to spend hours a day walking just to obtain a basic necessity," Chhatre says.

A fog-harvesting device consists of a fence-like mesh panel, which attracts droplets, connected to receptacles into which water drips. Chhatre has co-authored published papers on the materials used in these devices, and believes he has improved their efficacy. "The technical component of my research is done," Chhatre says. He is pursuing his work at MIT Sloan and the Legatum Center in order to develop a workable business plan for implementing fog-harvesting devices.

Interest in fog harvesting dates to the 1990s, and increased when new research on Stenocara gracilipes made a splash in 2001. A few technologists saw potential in the concept for people. One Canadian charitable organization, FogQuest, has tested projects in Chile and Guatemala.

Chhatre's training as a chemical engineer has focused on the wettability of materials, their tendency to either absorb or repel liquids (think of a duck's feathers, which repel water). A number of MIT faculty have made advances in this area, including Robert Cohen of the Department of Chemical Engineering; Gareth McKinley of the Department of Mechanical Engineering; and Michael Rubner of the Department of Materials Science and Engineering. Chhatre, who also received his master's degree in chemical engineering from MIT in 2009, is co-author, with Cohen and McKinley among other researchers, of three published papers on the kinds of fabrics and coatings that affect wettability.

One basic principle of a good fog-harvesting device is that it must have a combination of surfaces that attract and repel water. For instance, the shell of Stenocara gracilipes has bumps that attract water and troughs that repel it; this way, drops collects on the bumps, then run off through the troughs without being absorbed, so that the water reaches the beetle's mouth.

To build fog-harvesting devices that work on a human scale, Chhatre says, "The idea is to use the design principles we developed and extend them to this problem."

To build larger fog harvesters, researchers generally use mesh, rather than a solid surface like a beetle's shell, because a completely impermeable object creates wind currents that will drag water droplets away from it. In this sense, the beetle's physiology is an inspiration for human fog harvesting, not a template. "We tried to replicate what the beetle has, but found this kind of open permeable surface is better," Chhatre says. "The beetle only needs to drink a few micro-liters of water. We want to capture as large a quantity as possible."

In some field tests, fog harvesters have captured one liter of water (roughly a quart) per one square meter of mesh, per day. Chhatre and his colleagues are conducting laboratory tests to improve the water collection ability of existing meshes.

FogQuest workers say there is more to fog harvesting than technology, however. "You have to get the local community to participate from the beginning," says Melissa Rosato, who served as project manager for a FogQuest program that has installed 36 mesh nets in the mountaintop village of Tojquia, Guatemala, and supplies water for 150 people. "They're the ones who are going to be managing and maintaining the equipment." Because women usually collect water for households, Rosato adds, "If women are not involved, chances of a long-term sustainable project are slim."

Whatever Chhatre's success in the laboratory, he agrees it will not be easy to turn fog-harvesting technology into a viable enterprise. "My consumer has little monetary power," he notes. As part of his Legatum fellowship and Sloan studies, Chhatre is analyzing which groups might use his potential product. Chhatre believes the technology could also work on the rural west coast of India, north of Mumbai, where he grew up.

Another possibility is that environmentally aware communities, schools or businesses in developed countries might try fog harvesting to reduce the amount of energy needed to obtain water. "As the number of people and businesses in the world increases and rainfall stays the same, more people will be looking for alternatives," says Robert Schemenauer, the executive director of FogQuest.

Indeed, the importance of water-supply issues globally is one reason Chhatre was selected for his Legatum fellowship.

"We welcomed Shreerang as a Legatum fellow because it is an important problem to solve," notes Iqbal Z. Quadir, director of the Legatum Center. "About one-third of the planet's water that is not saline happens to be in the air. Collecting water from thin air solves several problems, including transportation. If people do not spend time fetching water, they can be productively employed in other things which gives rise to an ability to pay. Thus, if this technology is sufficiently advanced and a meaningful amount of water can be captured, it could be commercially viable some day."

Quadir also feels that if Chhatre manages to sell a sufficient number of collection devices in the developed world, it could contribute to a reduction in price, making it more viable in poor countries. "The aviation industry in its infancy struggled with balloons, but eventually became a viable global industry," Quadir adds. "Shreerang's project addresses multiple problems at the same time and, after all, the water that fills our rivers and lakes comes from air."

That said, fog harvesting remains in its infancy, technologically and commercially, as Chhatre readily recognizes. "This is still a very open problem," he says. "It's a work in progress."

Source: EurekAlert

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 Una dintre cele mai grave maladii dintre cele existente la ora actuala si din pacate una dintre cele mai raspandite, este diabetul. Foarte multi oameni sunt afectati de aceasta boala perfida, cu efecte devastatoare pe termen lung si care transforma viata suferinzilor intr-un cosmar. Desi s-au introdus, in ultimii ani, numeroase medicamente menite sa atenueze efectele bolii, un leac total nu s-a gasit si diabeticii continua sa suporte un intreg sir de privatiuni. O descoperire de ultima ora le va imbunatati, in buna masura, situatia, gratie ei agonia testelor zilnice de sange parand sa devina, in curand, o amintire...

Inventia la care ne referim consta intr-un senzor minuscul, implantat in ochiul bolnavului de diabet; dispozitivul contine o substanta chimica speciala care emite o lumina fluorescenta atunci cand intra in contact cu glucoza. Daca nivelul de glucoza din sange este ridicat, lumina fluorescenta va straluci mai puternic. Acest tip de lumina, similara celei infrarosii, nu poate fi vazuta de ochiul uman dar poate fi lesne detectata de un dispozitiv de citire care converteste datele obtinute in cifre, oferind nivelul exact al glucozei in sange. Diabeticii nu trebuie sa faca altceva decat sa tina, pret de cateva secunde, aparatul in dreptul ochiului si nivelul glucozei apare pe afisajul electronic al dispozitivului.

Procedura de implantare dureaza doar trei minute!

Dupa cum se stie, diabetul afecteaza la ora actuala zeci de milioane de persoane si probabil ca aproape la fel de multi au boala fara sa stie. Boala apare atunci cand pancreasul fie inceteaza sa mai produca insulina, fie produce, dar in cantitate insuficienta. Insulina este esentiala pentru a ajuta celulele musculare sa absoarba glucoza din hrana si sa o foloseasca drept combustibil, pentru nevoile energetice ale organismului. Fara un nivel corect de insulina se produce hiperglicemia, ce poate afecta ireversibil rinichii, ochii, inima etc.

Desi cele doua tipuri de diabet, care afecteaza in ultima vreme tot mai multi oameni de varsta mijlocie, pot fi adesea controlate prin dieta, cei cu diabet de tip I au adesea nevoie de o doza zilnica de insulina, pe tot parcursul vietii. Ei trebuie sa-si preleveze mostre de sange de pana la patru ori pe zi, pentru a se asigura ca nivelul de glucoza e stabil. Desi pentru unii acest lucru a devenit o rutina, multi se plang ca necesitatea constanta a acestor teste constituie o imensa povara.

In primul rand lor le era adresat dispozitivul numit GlucoWatch, brevetat in Marea Britanie, care masura nivelul de zahar din fluidele pielii. Inconvenientele sale erau ca  bateriile aveau nevoie de trei ore pentru a se incarca iar pacientii se plangeau adesea de iritatii ale pielii. Noul dispozitiv realizat de compania germana EyeSense va fi mult mai fiabil, intrucat se bazeaza pe un senzor ocular fabricat dintr-un gel pe baza de apa, neiritant, si care contine lectina si fluorofor. Doctorul aplica doua-trei picaturi de anestezic in coltul ochiului si apeleaza la un ac pentru a implanta senzorul in ochi.

Procedura nu dureaza mai mult de trei minute. Cand nivelul de glucoza creste, aceasta substanta interactioneaza cu lectina din interiorul implantului si astfel se elibereaza fluoroforul, ale carui molecule emit o lumina fluorescenta. De trei ori pe zi pacientul trebuie sa indrepte un dispozitiv de citire, numit fluorofotometru, spre ochi, iar acesta converteste instantaneu intensitatea luminii detectate in cifre. Cinci voluntari au testat deja implantul iar rezultatele au reflectat cu multa acuratete nivelul de glucoza din sange. Singurele probleme ar fi ca, dupa cate se pare, pretul implantului si al flurofotometrului vor fi destul de ridicate iar implantul nu va putea rezista decat un an, ulterior fiind necesara inlocuirea lui.


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Non solo vi è acqua sulla Luna, ma è molta di più di quanto si pensasse: sembra infatti che il nostro satellite ospiti, sotto la sua superficie, una quantità di acqua pari a quella presente nello strato superiore del mantello terrestre. A tre anni di distanza dal clamoroso annuncio della Nasa che stabiliva una volta per tutte la presenza del prezioso liquido sulla nostro satellite, lo stesso gruppo di ricercatori pubblica su Science la non meno sorprendente precisazione.

Autori dello studio sono i geologi della Brown University (Providence, Usa) e della Carnegie Institution di Washington, che per anni hanno analizzato i campioni di suolo lunare riportati dalla missione Apollo 17 della Nasa. Le loro conclusioni arrivano dall’analisi delle cosiddette inclusioni fuse, ovvero piccole bolle di roccia fusa intrappolate all'interno di cristalli nelle rocce prodotte dalle colate laviche. Si tratta quindi di campioni di magma che, non avendo subito gli effetti delle alte temperature, conservano ancora  tutte le sostanze volatili - tra cui l'acqua - alle stesse concentrazioni in cui si trovano nel mantello lunare.

Detail-luna acqua

Osservare queste pietre, formatesi con le eruzioni vulcaniche di circa tre miliardi di anni fa, è come guardare direttamente l'interno della Luna. I geologi hanno analizzato i cristalli con una microsonda ionica, uno strumento che determina la composizione chimica dei minerali, rilevando elementi presenti anche solo in tracce. Una volta misurata la concentrazione di acqua, gli scienziati sono riusciti a stimare la quantità del liquido presente nel mantello. E, sorpresa, i risultati dicono che potrebbe essere compresa tra 615 e 1410 ppm (parti per milione): cifre paragonabili a quelle del mantello terrestre (500-1000 ppm), e superiori di circa cento volte rispetto alle stime precedenti.

“Nel 2008 avevamo stabilito che il contenuto di acqua nel magma lunare avrebbe dovuto essere simile a quello della lava proveniente dal mantello superiore della Terra. Ora abbiamo provato che è realmente così”, ha detto Alberto E. Saal, tra gli autori dello studio. Tuttavia i ricercatori invitano alla cautela: questi dati non significano che la Luna sia davvero piena d'acqua, ma solo che vi sono dei luoghi in cui è più abbondante. Punto fondamentale, questo, perché altrimenti verrebbe a cadere la teoria più accreditata sull'origine della Luna, secondo cui il satellite sarebbe un frammento della Terra, sbalzato lontano dal pianeta quattro miliardi di anni fa, in seguito all'impatto con un oggetto di dimensioni simili a quelle di Marte. Un evento di tali proporzioni, infatti, avrebbe fatto evaporare tutta l'acqua presente sulla Luna. “Se tutta la Luna presentasse una quantità d'acqua equivalente a quella che abbiamo analizzato, allora la teoria dell'impatto gigante sarebbe compromessa. Come quest'acqua sia poi arrivata sul satellite, è un problema del tutto aperto”, ha concluso Saal.

Fonte: - Riferimenti: Science DOI: 10.1126/science.1204626; Nasa

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This method could pave the way for cheaper next-generation thin-film and flexible electronics. The work, which describes the results for films of several different compositions, appeared on Sunday in the journal Nature Materials.

The thin-film electronics behind today’s flat-panel displays are made of chaotically structured, or amorphous, silicon. But amorphous silicon is reaching its performance limits, and a new class of materials—amorphous oxides— will soon be making its commercial debut. Electrons in amorphous oxides can zoom through the material dozens of times as fast as they do in amorphous silicon, making for faster electronics. And unlike amorphous silicon, oxides carry current the same way in every direction, making them better candidates for bendable electronics like flexible solar arrays and roll-up displays.

To make these thin films, engineers primarily rely on ”sputtering,” in which vaporized material is flung at its target inside a vacuum chamber. This process would potentially be less costly if the material could be applied as a solution instead. But fans of the solution-based method have had to confront some inconvenient physics. Heat must be applied to condense the metal oxide, and the material performs best after it has been heated above 300 °C, which is about 100 degrees too hot for most flexible plastics.

Now Mercouri Kanatazidis, Tobin Marks, Antonio Facchetti, and Myung-Gil Kim of Northwestern University, in Evanston, Ill., think they’ve come up with a fix: replacing the external heat of an oven with the internal heat of a chemical reaction.

Many thin-film metal oxide solutions are made using water and metal-containing salts. When the temperature rises high enough, the oxygen atoms bind with the metal to form a chaotic tangle of metal-oxygen bonds. The team found that if they included a fuel like acetylacetone or urea in the mix, they could raise the internal energy of the mixture. Boosting the temperature to just 200 °C triggered a combustion reaction and enough self-generated heat to anneal metal-oxide films.

One of the team’s biggest challenges was finding a way to deal with structural changes created through the combustion process. The internal heat can create voids in the resulting films. These voids are useful for sensors and catalysts that require a lot of surface area, says team member Facchetti, who is also affiliated with Polyera Corp., in Skokie, Ill. But the gaps are counterproductive for thin-film electronics because they reduce the overlap between the atoms’ electron clouds and thus hinder the ability to transport current. ”One of the major challenges was to make sure we could make a film that is very dense,” Facchetti says. The team ultimately found it could circumvent the void problem by alternately depositing and annealing thin layers to build up the film.

One device made using the technique—an indium oxide transistor—boasted an electron mobility of 6 square centimeters per volt second, roughly 10 times that of thin-film amorphous silicon devices. That’s a heartening figure but one that will have to be backed up with more experiments, says John Wager of Oregon State University, in Corvallis, Ore. ”If the extra energy from combustion-based synthesis really does give you better-performing devices at low temperature, then that’s really nice,” Wager says. (See the feature article by John Wager and Randy Hoffman in the May 2011 issue of IEEE Spectrum for more on amorphous oxide semiconductors.)

One big question that will need to be answered in future work, Wager says, is how stable these devices can be. The threshold voltage needed to turn on thin-film transistors tends to drift with use, and that behavior ”tends to be more problematic at low temperature,” he says. ”If their combustion synthesis leads to more stable transistors, that could be really big.”

Source: spectrum

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By Admin (from 06/08/2011 @ 11:00:09, in ro - Stiinta si Societate, read 501 times)

 Ce puncte comune pot avea asa-zisele legi ale lui Murphy, horoscopul zilnic, tartinele care cad pe partea unsa si... incompetenta unora? Insasi aceasta intrebare pare cel putin ciudata. Totusi, sa nu va mire afland ca „intamplarea”, pe care tot dam vina atunci cand nu gasim explicatii pentru un fenomen sau o situatie oarecare, se bucura de toata atentia unor statisticieni, psihologi si economisti. Acestia afirma ca asemenea bizarerii au explicatii cat se poate de stiintifice!

Necazurile lui Don Quijote

Se spune ca, daca o persoana poate sa comita o greseala, atunci sigur o va comite. Nu-i asa ca vi s-a intamplat ca, aflandu-va la volanul masinii si fiind foarte grabit, toate semafoarele sa treaca pe rosu exact cand va apropiati de intersectie? „Asta numai mie mi se poate intampla.” – vine primul gand, ca din intamplare. Totusi, anecdoticele legi ale lui Murphy arata ca problema e valabila, teoretic, pentru oricine.

Si ele se bazeaza pe fapte suta la suta reale. La finele anilor 40, inginerul Edward Murphy efectua o serie de teste la o baza a USAir Force, compromise insa stupid de asistentul sau, care a montat invers doi captatori. Asa ca „legile” si corolarele lor au „curs” ca de la sine. Intre ele, nu mai putin faimoasa idee ca un necaz nu vine niciodata singur. Luati de pilda probabilitatea ca un avion sa se prabuseasca: in perioada 1995-2005, ea era de la 1 la 500.000 de zboruri.

Dar, ceea ce nu se intamplase in 10 ani, a avut loc in cateva zile: intre 2 si 23 august 2005, 5 avioane au pierit astfel. Sa mai amintim ca in 2000, turnarea filmului „Barbatul care l-a ucis pe Don Quijote” a fost oprita definitiv, din motive greu de acceptat: a plouat tot timpul, iar actorul Jean Rochefort, accidentat, nu a putut calari; si tocmai el juca rolul principal...

Totul e logic(a)

Hazardul nu repartizeaza in timp accidentele in mod uniform. Matematicienii spun ca exista putine probabilitati ca o serie neagra a aviatiei, de genul celei inregistrate in numai 22 de zile, sa se reia in urmatoarele 22 de zile, chiar daca pe glob exista 20.000 de zboruri cotidiene. Insa, pe masura ce creste numarul perioadelor de cate 22 de zile creste si probabilitatea nefasta, pana la circa 1 la 10 pe an. La fel e si cu semaforul: daca rulati constant cu 30 km/ ora, viteza pentru care sa presupunem ca toate semafoarele au fost sincronizate, calculele arata ca aveti toate sansele sa prindeti numai verdele!

Cat despre „nefericirile” lui Don Quijote, urmarea esecului filmului amintit a fost exact cum ar fi gandit-o Murphy: pe baza seriei negre a primei echipe, trei ani mai tarziu, alti realizatori au tras un making of parodic – „Pierdut in La Mancha”. Iar ca sa intram si in concretul cotidian al multimilor, merita precizat ca, de peste un veac (1906), traim cum s-ar zice cu „sabia lui Pareto” deasupra capului. Pareto a fost un economist italian, care a demonstrat ca 80% din produse sunt cumparate de 20% din populatie; si invers. Lege aplicata nu numai consumului, ci si multor domenii ale economiei.

Explicatia: efectul de inertie, adica dorinta de a ne imita vecinii, de a cumpara cam aceleasi marfuri, din aceleasi magazine. La urma-urmei, avem de-a face cu o inegalitate regasita grosso modo la scara planetara, in drama... bogatiilor: 10% din oamenii cei mai avuti detin 85% din bunurile mondiale, iar jumatate din cei mai saraci poseda doar 1% din bogatiile globului!


Aminteam de logica horoscopului care intotdeauna se potriveste cu cele traite zilnic de fiecare dintre noi (daca e intocmit cum scrie la carte), despre tendinta de a ne atinge nivelul maxim de incompetenta, exista si un principiu ce spune ca, daca avem mai mult timp pentru  a realiza o treaba anume, cu atat mai mult ne va lua ca s-o ducem la bun sfarsit. Si alte asemenea jocuri serioase ale hazardului (sic!), pentru care unii semeni poate chiar primesc cate un premiu Ig Nobel. Iar fiidca ele tot au un temei, nu e rau sa intram in tainele lor, putin cate putin. Macar pentru a nu cadea vreodata in gresala.


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By Admin (from 06/08/2011 @ 08:00:12, in it - Scienze e Societa, read 851 times)


Stiamo parlando di qualcosa di minuscolo, che possiede una massa e una carica elettrica pur non avendo dimensioni né una struttura interna. Insomma, un concetto abbastanza astratto, che richiede una buona dose di immaginazione. Di immaginazione non hanno invece bisogno i fisici che hanno appena eseguito una nuova e precisa misura di questa particella. E quel che si può dire, ora è che l’elettrone sembra proprio essere sferico.

Lo studio, presentato su Nature e coordinato da Jony Hudson dell'Imperial College di Londra, ha notevoli implicazioni per la fisica moderna, che spaziano dalla comprensione delle interazioni fondamentali all’evoluzione dell’Universo. Il risultato è ancora parziale, ma senza dubbio sarà di grande aiuto ai fisici teorici, in quanto le teorie più moderne delle interazioni fondamentali fanno precise previsioni sulle caratteristiche di questo curioso protagonista del mondo subnucleare.

Pur essendo la prima particella elementare scoperta (nel XIX secolo), l’elettrone ha ancora molti segreti. Sappiamo infatti che è fra le particelle elementari più leggere che si conoscano e che la sua carica elettrica è un’unità indivisibile. Tutte le particelle elementari isolate finora hanno infatti carica elettrica multipla di quella dell’elettrone. Ma le sorprese non finiscono qui: perché pur non avendo una struttura, l’elettrone può orientarsi nello spazio, essendo dotato di un momento magnetico intrinseco detto spin. In pratica, l’elettrone è come una minuscola calamita che si orienta in presenza di un campo magnetico, in modo analogo all’ago di una bussola.

Per studiare la forma dell’elettrone, i ricercatori hanno tentato di scoprire l’esistenza dell’analogo elettrico dello spin, detto momento di dipolo elettrico. Lo si può immaginare come una minuscola batteria che può ruotata da un campo elettrico. Ogni asimmetria nella forma dell’elettrone – o, più precisamente, delle sue interazioni con i campi elettrici esterni, si manifesta con la presenza di un momento di dipolo elettrico.

Finora il momento di dipolo elettrico dell’elettrone non è stato osservato, e gli scienziati come Hudson continuano a dargli la caccia, progettando esperimenti sempre più precisi. Nell’esperimento presentato su Nature, il team londinese ha utilizzato molecole di monofluoruro di itterbio (YbF), studiandone il comportamento in presenza di campi magnetici per ricavare le proprietà degli elettroni nella molecola. Pur senza ottenere un numero definito, i ricercatori hanno potuto affermare, con una precisione senza precedenti, che il momento di dipolo elettrico è compatibile con zero. In altre parole che l’elettrone potrebbe ben avere una forma sferica.

Fonte: - doi:10.1038/473459a - Credit immagine: Scienceheath

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Giuseppe Di Maio, T. G., Luigi Belbello, Antonio Padula, Cosimo Intrepido, Salvatore Di Matteo, Nazareno Matina, Agostino Castagnola, Vincenzo Lemno, LucianoB., Salvatore Pepe, W. D., Ilina Ioan, Carlo Saturno, Mehdi Kadi, Adriana Ambrosini, Ilie Nita, Mario Di Fonso, detenuto albanese, Giuseppe Denaro, Jean Jaques Olivier Esposito, Vasile Gavrilas, Gianluca Corsi, Jon R., Ciprian Florin Gheorghita, Salvatore Camelia, Antonino Montalto, Mahmoud Tawfic, Michele Massaro, Massimo B.

Nomi, uno dietro l'altro. Sono gli esseri umani che si sono ammazzati nella vergogna a cielo aperto delle carceri italiane dell'inizio dell'anno.

Una lista di nomi, cognomi e sigle, niente di più.

Intanto il caldo morde, l'inferno diventa sempre più insopportabile e nelle prigioni si deve combattere col coltello tra i denti per una doccia, per una passeggiata, per una visita in infermeria.

Un paese che tollera un'indecenza come questa è uno stato canaglia: proprio come quelli che di solito si bombardano, previo accorato dibattito parlamentare e conseguente decisione unanime di finanziamento, allo scopo di "esportare la democrazia".

Uno stato canaglia. Né più, né meno.

A volte penso che se tanto mi dà tanto qualcuno dovrebbe prendersi la briga di bombardare anche noi.


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The Dutch are well known for their ubiquitous bike lanes, to the point where Amsterdam is neck and neck with Copenhagen for the title of most bike-loving capital in Europe. Now, Denmark will have to come up with something big to match the latest plan from the Netherlands - the installation of solar panels in roads, starting with bike lanes.


Talk about the efficient use of space: if you're going to have roads (and hopefully you'll have bike lanes), why not put that space to work producing energy? Called the Solaroad, the project is the brainchild of Dutch research firm TNO. The idea is pretty straightforward: a layer of concrete forms the road itself. A centimeter thick layer of crystalline silicon solar cells is laid on top, and covered by a layer of toughened glass. The energy potential: 50kWh per square meter per year, which can then be used to power street lighting, traffic systems and households.

But it's still an idea in development, which is why TNO, working with the Province of North Holland, the consulting firm Ooms Averhorn Group and the tech firm Intech, is starting with a small-scale pilot program in the town of Krommenie, outside of Amsterdam. Scheduled for installation next year, the first Solaroad will hopefully allow its developers better implement many more throughout the country.

Maybe it'll even make it to the US one day- though in today's political climate, this probably costly project is unlikely to get much support in Congress. Well, we can dream.

Source: TreeHugger

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Ultimi commenti - Last comments - Ultimele comentarii:
sir are you encouraging people participate in some kind of game? ...where people give up their power? It never worked before .... that’s why I suggest instead of give up your power, exercise it from y...
05/10/2014 @ 08:45:09
By James Smith
Asta e marihoana nu?ei cine te poate opri so faci ,eu nu prefer astfel de fistractie deoarece am vazut ca dupa nu mai faci altceva fecit ca dormi bine,nu am incercat nu incerc dar nu opresc pe nimeni ...
30/09/2014 @ 09:34:56
By Miulesvu Corina Lucia
tovaraseilor .. nu confundati un sifonar sau turnator cuun ofiter sub acoperire.. e o mare diferenta ...
29/09/2014 @ 13:07:51
By Alex Andu
... deci şi Toma e securist, logic!
27/09/2014 @ 15:49:04
By Bogdan Sith Huşanu
Mai voinicilor,voi nu stiati ca inainte de 89,securistii erau omul si copacul,,ei acum sint si mai multi,cred ca au dat si lastari,ce naiba..!..
27/09/2014 @ 15:45:01
By Toma Pasculea
E greu de crezut că mişcă ceva de calibru în massmedia din orice ţară care să nu aibă vre-o treabă cu 'serviciile'. Cred că massmedia, instituţiile me...
27/09/2014 @ 15:41:52
By Alterul EgoulMeu
Manipulare, marca Basescu.
27/09/2014 @ 15:38:18
By Stela Andreica


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