Misiunea DSO este de a identifica și de a continua inițiativele de cercetare în materie de riscuri, de mare salarizare într-un spectru larg de discipline științifice și de inginerie și de a transforma aceste inițiative într-o nouă tehnologie radicală de schimbare a jocului pentru securitatea națională a SUA
Sunt create noi instrumente pentru cele mai grave scenarii de apă potabilă: contaminare chimică, biologică, radiologică și nucleară (CBRN);materialul se poate răspândi în apă rapid și cu precădere înainte de detectarea problemei;Setul de senzori CBRN disponibili, care pot fi utilizați pentru detectarea amenințărilor de contaminare a calității apei potabile în sistemul de distribuție, este foarte limitat
Pantaloni de luptă / tactici pentru operațiuni speciale de acoperire
au dezvoltat o tehnică care poate schimba rapid opacitatea unei ferestre, transformându-o în ceață, clară sau undeva între ele, cu mișcarea unui comutator.
| Posted: Mar 14, 2016 | |
Tunable nanowire windows for privacy, camouflage(Nanowerk News) Say goodbye to blinds. |
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| Researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences have developed a technique that can quickly change the opacity of a window, turning it cloudy, clear or somewhere in between with the flick of a switch. | |
| Tunable windows aren’t new but most previous technologies have relied on electrochemical reactions achieved through expensive manufacturing. This technology, developed by David Clarke, the Extended Tarr Family Professor of Materials, and postdoctoral fellow Samuel Shian, uses geometry adjust the transparency of a window. | |
| The research is described in journal Optics Letters („Electrically tunable window device”). | |
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| The tunable window is comprised of a sheet of glass or plastic, sandwiched between transparent, soft elastomers sprayed with a coating of silver nanowires, too small to scatter light on their own. | |
| But apply an electric voltage and things change quickly. | |
| With an applied voltage, the nanowires on either side of the glass are energized to move toward each other, squeezing and deforming the soft elastomer. Because the nanowires are distributed unevenly across the surface, the elastomer deforms unevenly. The resulting roughness causes light to scatter, turning the glass opaque. | |
| The change happens in less than a second. | |
| It’s like a frozen pond, said Shian. | |
| „If the frozen pond is smooth, you can see through the ice. But if the ice is heavily scratched, you can’t see through,” said Shian. | |
| Clarke and Shian found that the roughness of the elastomer surface depended on the voltage, so if you wanted a window that is only lightly clouded, you would apply less voltage than if you wanted a totally opaque window. | |
| „Because this is a physical phenomenon rather than based on a chemical reaction, it is a simpler and potentially cheaper way to achieve commercial tunable windows,” said Clarke. | |
| Current chemical-based controllable windows use vacuum deposition to coat the glass, a process that deposits layers of a material molecule by molecule. It’s expensive and painstaking. In Clarke and Shian’s method, the nanowire layer can be sprayed or peeled onto the elastomer, making the technology scalable for larger architectural projects. | |
| Next the team is working on incorporating thinner elastomers, which would require lower voltages, more suited for standard electrical supplies. | |
| Harvard’s Office of Technology Development has filed a patent application on the technology and is engaging with potential licensees in the glass manufacturing industry. |
| Source: Harvard John A. Paulson School of Engineering and Applied Sciences |
Wellbores forate pentru a extrage petrol și gaz pot fi armate în mod dramatic cu o cantitate mică de nanofibre modificate de grafină adăugate la un polimer și cu microunde, potrivit cercetătorilor Universității Rice
au combinat nanoribonii cu un polimer termosetat pe bază de ulei destinat să facă fântâni mai stabile și să reducă costurile de producție. Atunci când se vindecă cu microunde cu putere redusă care ies din ansamblul burghiu, compozitul va conecta fracturile microscopice care permit fluidului de foraj să treacă și să destabilizeze pereții.
| Posted: May 13, 2016 | |
Microwaved nanoribbons may bolster oil and gas wells(Nanowerk News) Wellbores drilled to extract oil and gas can be dramatically reinforced with a small amount of modified graphene nanoribbons added to a polymer and microwaved, according to Rice University researchers. |
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| The Rice labs of chemist James Tour and civil and environmental engineer Rouzbeh Shahsavari combined the nanoribbons with an oil-based thermoset polymer intended to make wells more stable and cut production costs. When cured in place with low-power microwaves emanating from the drill assembly, the composite would plug the microscopic fractures that allow drilling fluid to seep through and destabilize the walls. | |
| Results of their study appeared in the American Chemical Society journal ACS Applied Materials and Interfaces („Microwave Heating of Functionalized Graphene Nanoribbons in Thermoset Polymers for Wellbore Reinforcement”). | |
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| Rice University researchers have developed a method to treat composite materials of graphene nanoribbons and thermoset polymers with microwaves in a way that could dramatically reinforce wellbores for oil and gas production. (Image: Nam Dong Kim/Rice University) (click on image to enlarge) | |
| The researchers said that in the past, drillers have tried to plug fractures with mica, calcium carbonate, gilsonite and asphalt to little avail because the particles are too large and the method is not efficient enough to stabilize the wellbore. | |
| In lab tests, a polymer-nanoribbon mixture was placed on a sandstone block, similar to the rock that is encountered in many wells. The team found that rapidly heating the graphene nanoribbons to more than 200 degrees Celsius with a 30-watt microwave was enough to cause crosslinking in the polymer that had infiltrated the sandstone, Tour said. The microwave energy needed is just a fraction of that typically used by a kitchen appliance, he said. | |
| „This is a far more practical and cost-effective way to increase the stability of a well over a long period,” Tour said. | |
| In the lab, the nanoribbons were functionalized – or modified – with polypropylene oxide to aid their dispersal in the polymer. Mechanical tests on composite-reinforced sandstone showed the process increased its average strength from 5.8 to 13.3 megapascals, a 130 percent boost in this measurement of internal pressure, Shahsavari said. Similarly, the toughness of the composite increased by a factor of six. | |
| „That indicates the composite can absorb about six times more energy before failure,” he said. „Mechanical testing at smaller scales via nanoindentation exhibited even more local enhancement, mainly due to the strong interaction between nanoribbons and the polymer. This, combined with the filling effect of the nanoribbon-polymer into the pore spaces of the sandstone, led to the observed enhancements.” | |
| The researchers suggested a low-power microwave attachment on the drill head would allow for in-well curing of the nanoribbon-polymer solution. |
| Source: Rice University |
au inventat o modalitate de a construi un „metamaterial cuantic” – un material fabricat cu proprietati exotice care nu se gasesc in natura folosind atomi ultracold prinsi intr-un cristal artificial compus din lumina.Cercetătorii au descoperit că atomii de rubidiu sunt ideali pentru acest studiu, totuși atomii de bariu, calciu și cesiu pot fi prinși sau plantați în cristalul artificial, deoarece prezintă niveluri similare de energie. În timp ce cristalul artificial utilizat în studiu este descris ca fiind unidimensional, Jha a spus că aceeași abordare ar putea fi ușor extinsă pentru a crea structuri cristaline metamateriale cuantice 2-D și 3-D din lumină.
| Posted: May 11, 2016 | |
Scientists take a major leap toward a ‘perfect’ quantum metamaterial(Nanowerk News) Scientists have devised a way to build a “quantum metamaterial”—an engineered material with exotic properties not found in nature—using ultracold atoms trapped in an artificial crystal composed of light. The theoretical work represents a step toward manipulating atoms to transmit information, perform complex simulations or function as powerful sensors. |
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| The research team, led by scientists at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and UC Berkeley, proposes the use of an accordion-like atomic framework, or “lattice” structure, made with laser light to trap atoms in regularly spaced nanoscale pockets. Such a light-based structure, which has patterned features that in some ways resemble those of a crystal, is essentially a “perfect” structure—free of the typical defects found in natural materials. | |
| Researchers believe they can pinpoint the placement of a so-called “probe” atom in this crystal of light, and actively tune its behavior with another type of laser light (near-infrared light) to make the atom cough up some of its energy on demand in the form of a particle of light, or photon. | |
| This photon, in turn, can be absorbed by another probe atom (in the same or different lattice site) in a simple form of information exchange—like spoken words traveling between two string-connected tin cans. | |
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| The wavelike pattern at the top shows the accordion-like structure of a proposed quantum material—an artificial crystal made of light—that can trap atoms in regularly spaced nanoscale pockets. These pockets can be made to hold a large collection of ultracold “host” atoms (green), slowed to a standstill by laser light, and individually planted “probe” atoms (red) that can be made to transmit quantum information in the form of a photon (particle of light). The lower panel shows how the artificial crystal can be reconfigured with light from an open (hyperbolic) geometry to a closed (elliptical) geometry, which greatly affects the speed at which the probe atom can release a photon. | |
| “Our proposal is very significant,” said Xiang Zhang, director of Berkeley Lab’s Materials Sciences Division who led the related research paper, published in April in Physical Review Letters („Coherence-Driven Topological Transition in Quantum Metamaterials”). “We know that the enhancement and ultrafast control of single-photon emission lies at the heart of quantum technologies, in particular quantum information processing, and this is exactly what we have achieved here. Previous proposals can do one or the other but not both simultaneously.” | |
| Zhang is also a professor at UC Berkeley, director of the National Science Foundation’s Center for Scalable and Integrated Nanomanufacturing and a member of the Kavli Energy NanoScience Institute at Berkeley Lab and UC Berkeley. | |
| Pankaj K. Jha, a UC Berkeley postdoctoral researcher who is the lead author of the paper and works in Zhang’s group, said, “Now we have control over the speed of the release of a photon, so we can optically process information much faster, and efficiently transfer it from one point to another.” Other scientists who contributed to this work include Michael Mrejen, Jeongmin Kim, Chihhui Wu, Yuan Wang and Yuri V. Rostovtsev. | |
| This ability to release a photon at fast rates, and to transmit it with low losses from one atom to another, is a vital step in processing information for quantum computation, which could use an array of these controlled photon releases to carry out complex calculations far more rapidly than is possible in modern computers. | |
| A quantum computer, which the tech industry and scientific community are hotly pursuing because of its potential to perform more complex calculations than are possible using modern supercomputers, could tap into the bizarre quantum realm in which ordinary physics rules don’t apply. | |
| While today’s computers can store information as binary bits—either ones or zeroes—a quantum compter would use “qubits” in which an individual bit of information can simultaneously exist in multiple states. These qubits could take the form of atoms, photons, electrons, or even as an individual fundamental property of a particle, and would exponentially increase the number of calculations a computer could perform in an instant. | |
| The non-uniform distribution of the ultracold atoms in the artificial crystal is a key to this latest study, said Jha. “It makes the crucial difference for creating a ‘perfectly’ lossless and reconfigurable quantum metamaterial,” he said, allowing the optical structure of the artificial crystal to be reconfigured from an open geometry (hyperbolic-shaped) to a closed one (elliptical) at the same frequency and with ultrafast timing. This controllable shape-change dramatically changes the speed at which a probe atom in the artificial crystal releases a photon. | |
| The latest proposal suggests that it is possible to speed up the rate at which a probe atom can emit a photon from nanoseconds, or billionths of a second, to picoseconds, or trillionths of a second. Also, this process is importantly considered „lossless,” meaning the photons would not lose any of their energy to their surrounding structure as they likely would in a traditional material. This overcomes one hurdle toward quantum computing and information processing. | |
| Atoms planted in the artificial crystal could also possibly be induced to hop from one place to another. In this case, the atoms could themselves serve as the information carriers in a quantum computer or be arranged as quantum sensors, Jha said. | |
| Jha noted that this latest study marries metamaterials research with the science of “cold atoms,” which are atoms that have been slowed and even brought to a standstill using laser light, which in the process chills them to supercool temperatures. He said, “This integration has solved some of the outstanding challenges for metamaterial platforms and outperforms other designs in several key aspects crucial for quantum technologies.” | |
| The researchers found that rubidium atoms are ideally suited for this study, however barium, calcium and cesium atoms can also be trapped or planted in the artificial crystal, as they exhibit similar energy levels. While the artificial crystal used in the study is described as one-dimensional, Jha said the same approach could be easily extended to create 2-D and 3-D quantum metamaterial crystal structures out of light. | |
| To realize the proposed metamaterial in an actual experiment, Zhang and Jha said the research team would need to trap several atoms per lattice site in the artificial crystal, and to hold those atoms in the lattice even when they are excited to higher energy states. | |
| Zhang said, “Berkeley Lab has been a leader in groundbreaking research in metamaterials, and this work could open new realms of opportunities for quantum light-matter interactions, with enticing applications in quantum information science.” | |
| Jha added, “We believe that the combination of these two contemporary realms of science will help to address key challenges in both fields and open an entirely new research direction at the interface of quantum photonics and artificial materials.” |
| Source: Lawrence Berkeley National Laboratory |
Read more: Scientists take a major leap toward a ‘perfect’ quantum metamaterial
Materialele alternative investigate ca înlocuitori ITO au inclus grafen, nanotuburi de carbon și filme aleatoare de nanoparticule metalice. Acest studiu a arătat cum au apărut filmele de nanofire din argint ca fiind cel mai puternic concurent, datorită transmisiilor și conductivităților care se pot potrivi și depășesc ușor cele ale ITO. Acesta este un material care constă din fire care sunt de peste o mie de ori mai subțiri decât părul uman, care formează o rețea conductivă interconectată.
| Posted: May 11, 2016 | |
New research shows how silver could be the key to gold-standard flexible gadgets(Nanowerk News) Research published in the journals Materials Today Communications and Scientific Reports („Predicting the optoelectronic properties of nanowire films based on control of length polydispersity”) has described how silver nanowires are proving to be the ideal material for flexible, touch-screen technologies while also exploring how the material can be manipulated to tune its performance for other applications. Currently, touch screen devices mainly rely on electrodes made from indium tin oxide (ITO), a material that is expensive to source, expensive to process and very brittle. |
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| Silver nanowires are an ideal material for current and future flexible touch-screen technologies. | |
| A team from the University of Surrey, led by Professor Alan Dalton and in collaboration with M-SOLV Ltd, a touch-sensor manufacturer based in Oxford, looked to alternative materials to overcome the challenges of ITO, which is suffering from supply uncertainty. Alternative materials investigated as ITO replacements have included graphene, carbon nanotubes and random metal nanowire films. This study showed how silver nanowire films have emerged as the strongest competitor, due to transmittances and conductivities which can match and readily exceed those of ITO. This is a material that consists of wires which are over a thousand times thinner than a human hair, that form an interconnected conductive network. | |
| Showcasing a new process | |
| Matthew Large, the first author on the research published in Scientific Reports described the importance of these latest results. “Our research hasn’t just identified silver nanowires as a viable replacement touchscreen material, but has gone one step further in showing how a process called ‘ultrasonication’ can allow us to tailor performance capabilities. By applying high frequency sound energy to the material we can manipulate how long the nanosized ‘rods’ of silver are. This allows us to tune how transparent or how conductive our films are, which is vital for optimising these materials for future technologies like flexible solar cells and roll-able electronic displays.” | |
| In a paper published last month in Materials Today Communications, the same team, showed how silver nanowires can be processed using the same laser ablation technique commonly used to manufacture ITO devices. Using this technique, the team produced a fully operating five inch multi-touch sensor, identical to those typically used in smartphone technology. They found it performed comparably to one based on ITO but used significantly less energy to produce. | |
| “Not only does this flexible material perform very well, we have shown that it is a viable alternative to ITO in practical devices,” concluded Professor Dalton. “The fact we are able to produce devices using similar methods as currently in use, but in a less energy-intensive way is an exciting step towards flexible gadgets that do not just open the door for new applications, but do so in a much greener way.” | |
| An easy to deploy alternative | |
| Maria Cann, a technologist from M-SOLV and first author on the Materials Today Communications paper added ““We are seeing a lot of interest from our customers in silver nanowire films as an ITO replacement in devices. This work is a really important step in establishing exactly which sensor designs can make good nanowire products. The fact that the nanowire films are processed by the same laser techniques as ITO makes the transition from ITO to nanowires really straightforward. It won’t be long before we are all using nanowires in our electronic devices.” | |
| The team, now based at the University of Sussex is now looking to develop the scalability of the process to make it more industrially viable. One limiting factor is the current cost of silver nanowires. |
| Source: University of Surrey |
Read more: New research shows how silver could be the key to gold-standard flexible gadgets
primul robot echipat cu un pistol VIDEO;prima masina compacta din lume echipata cu propriile sale arme; cantareste 12 Kg si are vizibilitate de 360 de grade.
Oamenii de stiinta au inventat o modalitate de a construi un „metamaterial cuantic” – un material fabricat cu proprietati exotice care nu se gaseste in natura folosind atomi ultracold prinsi intr-un cristal artificial compus din lumina.Manipularea atomilor pentru a transmite informații, a efectua simulări complexe sau a funcționa ca senzori puternici.
| Posted: May 11, 2016 | |
Scientists take a major leap toward a ‘perfect’ quantum metamaterial(Nanowerk News) Scientists have devised a way to build a “quantum metamaterial”—an engineered material with exotic properties not found in nature—using ultracold atoms trapped in an artificial crystal composed of light. The theoretical work represents a step toward manipulating atoms to transmit information, perform complex simulations or function as powerful sensors. |
|
| The research team, led by scientists at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and UC Berkeley, proposes the use of an accordion-like atomic framework, or “lattice” structure, made with laser light to trap atoms in regularly spaced nanoscale pockets. Such a light-based structure, which has patterned features that in some ways resemble those of a crystal, is essentially a “perfect” structure—free of the typical defects found in natural materials. | |
| Researchers believe they can pinpoint the placement of a so-called “probe” atom in this crystal of light, and actively tune its behavior with another type of laser light (near-infrared light) to make the atom cough up some of its energy on demand in the form of a particle of light, or photon. | |
| This photon, in turn, can be absorbed by another probe atom (in the same or different lattice site) in a simple form of information exchange—like spoken words traveling between two string-connected tin cans. | |
 |
|
| The wavelike pattern at the top shows the accordion-like structure of a proposed quantum material—an artificial crystal made of light—that can trap atoms in regularly spaced nanoscale pockets. These pockets can be made to hold a large collection of ultracold “host” atoms (green), slowed to a standstill by laser light, and individually planted “probe” atoms (red) that can be made to transmit quantum information in the form of a photon (particle of light). The lower panel shows how the artificial crystal can be reconfigured with light from an open (hyperbolic) geometry to a closed (elliptical) geometry, which greatly affects the speed at which the probe atom can release a photon. | |
| “Our proposal is very significant,” said Xiang Zhang, director of Berkeley Lab’s Materials Sciences Division who led the related research paper, published in April in Physical Review Letters(„Coherence-Driven Topological Transition in Quantum Metamaterials”). “We know that the enhancement and ultrafast control of single-photon emission lies at the heart of quantum technologies, in particular quantum information processing, and this is exactly what we have achieved here. Previous proposals can do one or the other but not both simultaneously.” | |
| Zhang is also a professor at UC Berkeley, director of the National Science Foundation’s Center for Scalable and Integrated Nanomanufacturing and a member of the Kavli Energy NanoScience Institute at Berkeley Lab and UC Berkeley. | |
| Pankaj K. Jha, a UC Berkeley postdoctoral researcher who is the lead author of the paper and works in Zhang’s group, said, “Now we have control over the speed of the release of a photon, so we can optically process information much faster, and efficiently transfer it from one point to another.” Other scientists who contributed to this work include Michael Mrejen, Jeongmin Kim, Chihhui Wu, Yuan Wang and Yuri V. Rostovtsev. | |
| This ability to release a photon at fast rates, and to transmit it with low losses from one atom to another, is a vital step in processing information for quantum computation, which could use an array of these controlled photon releases to carry out complex calculations far more rapidly than is possible in modern computers. | |
| A quantum computer, which the tech industry and scientific community are hotly pursuing because of its potential to perform more complex calculations than are possible using modern supercomputers, could tap into the bizarre quantum realm in which ordinary physics rules don’t apply. | |
| While today’s computers can store information as binary bits—either ones or zeroes—a quantum compter would use “qubits” in which an individual bit of information can simultaneously exist in multiple states. These qubits could take the form of atoms, photons, electrons, or even as an individual fundamental property of a particle, and would exponentially increase the number of calculations a computer could perform in an instant. | |
| The non-uniform distribution of the ultracold atoms in the artificial crystal is a key to this latest study, said Jha. “It makes the crucial difference for creating a ‘perfectly’ lossless and reconfigurable quantum metamaterial,” he said, allowing the optical structure of the artificial crystal to be reconfigured from an open geometry (hyperbolic-shaped) to a closed one (elliptical) at the same frequency and with ultrafast timing. This controllable shape-change dramatically changes the speed at which a probe atom in the artificial crystal releases a photon. | |
| The latest proposal suggests that it is possible to speed up the rate at which a probe atom can emit a photon from nanoseconds, or billionths of a second, to picoseconds, or trillionths of a second. Also, this process is importantly considered „lossless,” meaning the photons would not lose any of their energy to their surrounding structure as they likely would in a traditional material. This overcomes one hurdle toward quantum computing and information processing. | |
| Atoms planted in the artificial crystal could also possibly be induced to hop from one place to another. In this case, the atoms could themselves serve as the information carriers in a quantum computer or be arranged as quantum sensors, Jha said. | |
| Jha noted that this latest study marries metamaterials research with the science of “cold atoms,” which are atoms that have been slowed and even brought to a standstill using laser light, which in the process chills them to supercool temperatures. He said, “This integration has solved some of the outstanding challenges for metamaterial platforms and outperforms other designs in several key aspects crucial for quantum technologies.” | |
| The researchers found that rubidium atoms are ideally suited for this study, however barium, calcium and cesium atoms can also be trapped or planted in the artificial crystal, as they exhibit similar energy levels. While the artificial crystal used in the study is described as one-dimensional, Jha said the same approach could be easily extended to create 2-D and 3-D quantum metamaterial crystal structures out of light. | |
| To realize the proposed metamaterial in an actual experiment, Zhang and Jha said the research team would need to trap several atoms per lattice site in the artificial crystal, and to hold those atoms in the lattice even when they are excited to higher energy states. | |
| Zhang said, “Berkeley Lab has been a leader in groundbreaking research in metamaterials, and this work could open new realms of opportunities for quantum light-matter interactions, with enticing applications in quantum information science.” | |
| Jha added, “We believe that the combination of these two contemporary realms of science will help to address key challenges in both fields and open an entirely new research direction at the interface of quantum photonics and artificial materials.” |
| Source: Lawrence Berkeley National Laboratory |
DARPA astăzi găzduiește la Pentagon, oferind comunității Departamentului Apărării o privire de ansamblu asupra portofoliului divers de tehnologii și sisteme militare ale agenției
