a creat un senzor productiv în masă, care poate detecta nivelele de amoniac în respirație – o descoperire care ar putea elimina utilizarea acelor în rândul a mii de pacienți
sunt un Graal Sfânt pentru oamenii de știință, cu aplicații potențiale care includ explorarea peisajelor planetelor îndepărtate
Acestea sunt făcute cu un coș de trepte de roți, înălțate de două picioare, care se rostogolesc în jurul podelei și care își proclamă descoperirile ca fiind „un ochi”, o cameră atașată, cade pe ele
ar putea inspira oamenii de stiinta pentru a dezvolta un instrument de cost pentru a detecta rapid arme chimice in aer; au fost în măsură să detecteze prezența unui agent nervos legat de gazul sarin la un nivel scăzut
But beyond these tools, we also need to exercise comparative phylogenetic imagination, hack new theory , and hazard wanton inference.
In applying hard limiters to classify the protein kits we find in cells-namely as receptores, enzymes , and ion channels -we end up with quite a salad of their associated protagonists
dispozitive pentru lentile de contact inteligente
dispozitivul manipulează lumina într-o asemenea măsură încât să poată filtra anumite culori în timp ce este încă transparent și ar putea fi utilizat în viitor pentru a face lentile de contact inteligente
noi nanoparticule cu potential de a trata cancerul ocular
Inginerii de la Universitatea din Utah au descoperit un nou tip de material semiconductor 2D pentru electronică, care deschide ușa pentru computerele mult mai rapide și smartphone-urile care consumă și mai puțină putere.
Semiconductorul, realizat din elemente de staniu și oxigen sau monoxid de staniu (SnO), este un strat de material 2D cu un singur atom gros, permițând încărcăturilor electrice să se deplaseze mult mai repede decât materialele convenționale 3D, cum ar fi siliciul. Acest material ar putea fi folosit în tranzistori, sângele vieții tuturor dispozitivelor electronice, cum ar fi procesoarele de calculator și procesoarele grafice în computerele desktop și dispozitivele mobile
| Posted: Feb 15, 2016 | |
Engineers discover a new kind of 2D semiconducting material for electronics(Nanowerk News) University of Utah engineers have discovered a new kind of 2D semiconducting material for electronics that opens the door for much speedier computers and smartphones that also consume a lot less power. |
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| The semiconductor, made of the elements tin and oxygen, or tin monoxide (SnO), is a layer of 2D material only one atom thick, allowing electrical charges to move through it much faster than conventional 3D materials such as silicon. This material could be used in transistors, the lifeblood of all electronic devices such as computer processors and graphics processors in desktop computers and mobile devices. The material was discovered by a team led by University of Utah materials science and engineering associate professor Ashutosh Tiwari. | |
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| University of Utah materials science and engineering associate professor Ashutosh Tiwari holds up a substrate layered with a newly discovered 2-D material made of tin and oxygen. Tiwari and his team have discovered this new material, tin monoxide, which allows electrical charges to move through it much faster than common 3-D material such as silicon. This breakthrough in semiconductor material could lead to much faster computers and mobile devices such as smartphones that also run on less power and with less heat. (Photo: Dan Hixson/University of Utah College of Engineering) | |
| A paper describing the research was published online Monday, Feb. 15, 2016 in the journal, Advanced Electronic Materials („2D Tin Monoxide—An Unexplored p-Type van der Waals Semiconductor: Material Characteristics and Field Effect Transistors”). The paper, which also will be the cover story on the printed version of the journal, was co-authored by University of Utah materials science and engineering doctoral students K. J. Saji and Kun Tian, and Michael Snure of the Wright-Patterson Air Force Research Lab near Dayton, Ohio. | |
| Transistors and other components used in electronic devices are currently made of 3D materials such as silicon and consist of multiple layers on a glass substrate. But the downside to 3D materials is that electrons bounce around inside the layers in all directions. | |
| The benefit of 2D materials, which is an exciting new research field that has opened up only about five years ago, is that the material is made of one layer the thickness of just one or two atoms. Consequently, the electrons „can only move in one layer so it’s much faster,” says Tiwari. | |
| While researchers in this field have recently discovered new types of 2D material such as graphene, molybdenun disulfide and borophene, they have been materials that only allow the movement of N-type, or negative, electrons. In order to create an electronic device, however, you need semiconductor material that allows the movement of both negative electrons and positive charges known as „holes.” The tin monoxide material discovered by Tiwari and his team is the first stable P-type 2D semiconductor material ever in existence. | |
| „Now we have everything – we have P-type 2D semiconductors and N-type 2D semiconductors,” he says. „Now things will move forward much more quickly.” | |
| Now that Tiwari and his team have discovered this new 2D material, it can lead to the manufacturing of transistors that are even smaller and faster than those in use today. A computer processor is comprised of billions of transistors, and the more transistors packed into a single chip, the more powerful the processor can become. | |
| Transistors made with Tiwari’s semiconducting material could lead to computers and smartphones that are more than 100 times faster than regular devices. And because the electrons move through one layer instead of bouncing around in a 3D material, there will be less friction, meaning the processors will not get as hot as normal computer chips. They also will require much less power to run, a boon for mobile electronics that have to run on battery power. Tiwari says this could be especially important for medical devices such as electronic implants that will run longer on a single battery charge. | |
| „The field is very hot right now, and people are very interested in it,” Tiwari says. „So in two or three years we should see at least some prototype device.” |
| Source: University of Utah |
Este ieftin să producă și deloc toxice, dioxidul de titan (cunoscut ca titania) are multe utilizări. Este folosit ca un pigment pentru a asigura albitatea și opacitatea pentru totul, de la săpunuri, cosmetice, vopsele, hârtie la alimente, pastă de dinți și medicamente. Este, de asemenea, utilizat pe scară largă ca o protecție solară, datorită capacităților puternice de absorbție a luminii UV.
Este, de asemenea, un fotocatalizator excelent, reacționând sub lumină ultravioletă pentru a deveni un agent de sterilizare. Totuși, deoarece lumina UV reprezintă doar 5% din radiația solară, titanele albe sunt relativ ineficiente în acest rol.
În acest studiu, cercetătorii au adăugat un compus obișnuit prezent în coloranții de păr în timpul preparării dioxidului de titan pentru a crea „titania neagră”. Deoarece negrul absoarbe o gamă mult mai largă a spectrului solar, titanul negru prezintă o activitate fotocatalitică mult mai eficientă atât în domeniul luminii UV, cât și al luminii vizibile.
Ca atare, titanii negri găsesc utilizări semnificative în instalațiile de tratare a apei și cum ar fi curățarea bazinelor. Acționat numai de lumina soarelui, este capabil să descompună poluanții organici și să purifice apa.
Se poate aplica și pe drumurile, fațadele și terasele clădirilor, unde acest „praf negru”funcționează pentru a elimina oxidul de azot din atmosferă și a îmbunătăți calitatea aerului.a modificat culoarea dioxidului de titan de la alb la negru pentru a fi utilizat ca agent eficient de sterilizare, eliminând contaminanții organici din aer și apă.
| Posted: Feb 12, 2016 | |
New solar-powered organic compound to tackle air and water pollution(Nanowerk News) Nanoscientists at the Univeristy of Alicante have modified a commonly-used compound, titanium dioxide, turning it from white to black to boost its efficiency and make environmental applications a real possibility. |
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| Researcher Elena Serrano at the Universidad de Alicante (University of Alicante, UA) has modified the colour of titanium dioxide from white to black for use as an efficient sterilising agent, removing organic contaminants from air and water. | |
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| Black and white titanias. (Image: NANOMOL, University of Alicante) | |
| Cheap to produce and not at all toxic, titanium dioxide (known as titania) has many uses. It is used as a pigment to provide whiteness and opacity to everything from soaps, cosmetics, paints, paper to foods, toothpaste and medicines. It is also widely used as a sunscreen, due to its strong UV light-absorbing capabilities. | |
| It is also an excellent photocatalyst, reacting under ultraviolet light to become a sterilising agent. However, since UV light accounts for just 5% of solar radiation, white titania is relatively inefficient in this role. | |
| In this study, researchers added a common compound present in hair dyes during the preparation of the titanium dioxide to create “black titania”. Since black absorbs a much larger range of the solar spectrum, black titania presents a much more efficient photocatalytic activity in both the UV and visible light ranges. | |
| As such, black titania finds significant uses in water treatment plants and such as pool cleaning. Powered only by sunlight, it is able to break down organic pollutants and purify the water. | |
| It can also be applied to roads, building facades and terraces, where this “black dust” works to remove nitrogen oxide from the atmosphere and improve air quality. | |
| Although similar technologies do already exist, “they generally require the use of noble metals like gold, or are the result of very complicated synthesis procedures, both of which are very expensive. Our black titania is much more efficient and cost-effective to produce, needing only water, alcohol and mild temperatures” (Serrano). | |
| The simple and cost-effective new procedure has been patented by the UA under the title (translated) “Procedure for the in-situ synthesis of functionalised titanias and their uses”. Elena Serrano appears as co-author, alongside the director of the UV’s Molecular Nanotechnology Lab (NANOMOL), Javier García, where the work has been carried out. |
| Source: Univeristy of Alicante |
Read more: New solar-powered organic compound to tackle air and water pollution
a crea grafenă flexibilă, personalizată și cu performanțe ridicate: stratificându-l pe partea de sus a sticlei comune. Acest proces scalabil și ieftin facilitează deschiderea unei noi clase de dispozitive microelectronice și optoelectronice – totul de la celule solare eficiente la ecrane tactile.De exemplu, conductivitatea ridicată și transparența graphenei o fac un candidat foarte promițător ca un electrod transparent și conducător pentru a înlocui oxidul de staniu indiu relativ fragil și scump (ITO) în aplicații cum ar fi celule solare, diode emițătoare de lumină organică (OLED) afișaje și ecrane tactile. Pentru a înlocui ITO, trebuie dezvoltate metode scalabile și cu costuri scăzute pentru a controla rezistența grafenului la fluxul de curent electric prin controlarea puterii de dopaj. Acest nou sistem de sticla-grafen se poate ridica la aceasta provocare, spun cercetatorii.
| Posted: Feb 12, 2016 | |
Graphene leans on glass to advance electronics(Nanowerk News) Graphene, the two-dimensional powerhouse, packs extreme durability, electrical conductivity, and transparency into a one-atom-thick sheet of carbon. Despite being heralded as a breakthrough „wonder material,” graphene has been slow to leap into commercial and industrial products and processes. |
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| Now, scientists have developed a simple and powerful method for creating resilient, customized, and high-performing graphene: layering it on top of common glass. This scalable and inexpensive process helps pave the way for a new class of microelectronic and optoelectronic devices—everything from efficient solar cells to touch screens. | |
| The collaboration—led by scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory, Stony Brook University (SBU), and the Colleges of Nanoscale Science and Engineering at SUNY Polytechnic Institute—published their results February 12, 2016, in the journal Scientific Reports („Spontaneous and strong multi-layer graphene n-doping on soda-lime glass and its application in graphene-semiconductor junctions”). | |
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| Left: Schematic of a graphene field-effect-transistor used in this study. The device consists of a solar cell containing graphene stacked on top of a high-performance copper indium gallium diselenide (CIGS) semiconductor, which in turn is stacked on an industrial substrate (either soda-lime glass, SLG, or sodium-free borosilicate glass, BSG). The research revealed that the SLG substrate serves as a source of sodium doping, and improved device performance in a way not seen in the sodium-free substrate. Right: A scanning electron micrograph of the device as seen from above, with the white scale bar measuring 10 microns, and a transmission electron micrograph inset of the CIGS/graphene interface where the white scale bar measures 100 nanometers. (click on image to enlarge) | |
| „We believe that this work could significantly advance the development of truly scalable graphene technologies,” said study coauthor Matthew Eisaman, a physicist at Brookhaven Lab and professor at SBU. | |
| The scientists built the proof-of-concept graphene devices on substrates made of soda-lime glass—the most common glass found in windows, bottles, and many other products. In an unexpected twist, the sodium atoms in the glass had a powerful effect on the electronic properties of the graphene. | |
| „The sodium inside the soda-lime glass creates high electron density in the graphene, which is essential to many processes and has been challenging to achieve,” said coauthor Nanditha Dissanayake of Voxtel, Inc., but formerly of Brookhaven Lab. „We actually discovered this efficient and robust solution during the pursuit of something a bit more complex. Such surprises are part of the beauty of science.” | |
| Crucially, the effect remained strong even when the devices were exposed to air for several weeks—a clear improvement over competing techniques. | |
| The experimental work was done primarily at Brookhaven’s Sustainable Energy Technologies Department and the Center for Functional Nanomaterials (CFN), which is a DOE Office of Science User Facility. | |
| The graphene tweaks in question revolve around a process called doping, where the electronic properties are optimized for use in devices. This adjustment involves increasing either the number of electrons or the electron-free „holes” in a material to strike the perfect balance for different applications. For successful real-world devices, it is also very important that the local number of electrons transferred to the graphene does not degrade over time. | |
| „The graphene doping process typically involves the introduction of external chemicals, which not only increases complexity, but it can also make the material more vulnerable to degradation,” Eisaman said. „Fortunately, we found a shortcut that overcame those obstacles.” | |
| The team initially set out to optimize a solar cell containing graphene stacked on a high-performance copper indium gallium diselenide (CIGS) semiconductor, which in turn was stacked on an industrial soda-lime glass substrate. | |
| The scientists then conducted preliminary tests of the novel system to provide a baseline for testing the effects of subsequent doping. But these tests exposed something strange: the graphene was already optimally doped without the introduction of any additional chemicals. | |
| „To our surprise, the graphene and CIGS layers already formed a good solar cell junction!” Dissanayake said. „After much investigation, and the later isolation of graphene on the glass, we discovered that the sodium in the substrate automatically created high electron density within our multi-layered graphene.” | |
| Pinpointing the mechanism by which sodium acts as a dopant involved a painstaking exploration of the system and its performance under different conditions, including making devices and measuring the doping strength on a wide range of substrates, both with and without sodium. | |
| „Developing and characterizing the devices required complex nanofabrication, delicate transfer of the atomically thin graphene onto rough substrates, detailed structural and electro-optical characterization, and also the ability to grow the CIGS semiconductor,” Dissanayake said. „Fortunately, we had both the expertise and state-of-the-art instrumentation on hand to meet all those challenges, as well as generous funding.” | |
| The bulk of the experimental work was conducted at Brookhaven Lab using techniques developed in-house, including advanced lithography. For the high-resolution electron microscopy measurements, CFN staff scientists and study coauthors Kim Kisslinger and Lihua Zhang lent their expertise. Coauthors Harry Efstathiadis and Daniel Dwyer—both at the College of Nanoscale Science and Engineering at SUNY Polytechnic Institute—led the effort to grow and characterize the high-quality CIGS films. | |
| „Now that we have demonstrated the basic concept, we want to focus next on demonstrating fine control over the doping strength and spatial patterning,” Eisaman said. | |
| The scientists now need to probe more deeply into the fundamentals of the doping mechanism and more carefully study material’s resilience during exposure to real-world operating conditions. The initial results, however, suggest that the glass-graphene method is much more resistant to degradation than many other doping techniques. | |
| „The potential applications for graphene touch many parts of everyone’s daily life, from consumer electronics to energy technologies,” Eisaman said. „It’s too early to tell exactly what impact our results will have, but this is an important step toward possibly making some of these applications truly affordable and scalable.” | |
| For example, graphene’s high conductivity and transparency make it a very promising candidate as a transparent, conductive electrode to replace the relatively brittle and expensive indium tin oxide (ITO) in applications such as solar cells, organic light emitting diodes (OLEDs), flat panel displays, and touch screens. In order to replace ITO, scalable and low-cost methods must be developed to control graphene’s resistance to the flow of electrical current by controlling the doping strength. This new glass-graphene system could rise to that challenge, the researchers say. |
| Source: Brookhaven National Laboratory |
Aplicațiile ulterioare ale unei astfel de metafore se pot referi la realizarea amplitudinii și a profilului de fază reglabil pentru ingineria acustică, care ar permite manipularea unei traiectorii de propagare a undelor acustice pentru aplicații speciale
