#Production of Special Coating to Increase Efficiency of Solar cells in Iran Results of the experiments prove the increase in the efficiency of the produced cells.
The solar cells can be used to produce electricity for industrial applications, including domestic appliance, automotive and aerospace after being produced mass.
In recent years, dye sensitized solar cells have become very important as the third generation of solar cells. The cheap equipment has very simple production technology
and study the performance of a type of coating to be used in dye sensitized solar cells. Titanium dioxide nanoparticles doped with elements such as strontium
and chrome were used in the production of the coating. It can be expressed that the increase in the efficiency of the cells in comparison with the cells produced on the base of usual coatings containing titanium dioxide is due to the increase in the current density in their short circuits.
Among other advantages of the cells, mention can be made of simple production method, appropriate final price and high transparency for the light.
The coating of nanoparticles contains titanium dioxide and other spherical nanoparticles in average size of 60 nm.
Crystalline structure chemical structure and composition of the coatings have been controlled in a way that it increases the current density in short circuits of dye sensitized solar cells.
Results of the research have been published in Journal of Colloid and Interface Science, vol. 460,2015, pp. 18-28 8
Finding could have implications for high-temperature superconductivity A team of physicists led by Caltech's David Hsieh has discovered an unusual form of matter--not a conventional metal, insulator,
This phase, characterized by an unusual ordering of electrons, offers possibilities for new electronic device functionalities and could hold the solution to a longstanding mystery in condensed matter physics having to do with high-temperature superconductivity--the ability
for some materials to conduct electricity without resistance, even at"high temperatures approaching-100 degrees Celsius."
and not based on any prior theoretical prediction,"says Hsieh, an assistant professor of physics, who previously was on a team that discovered another form of matter called a topological insulator."
which provide the playgrounds in which to search for new macroscopic physical properties.""Hsieh and his colleagues describe their findings in the November issue of Nature Physics,
Liuyan Zhao, a postdoctoral scholar in Hsieh's group, is lead author on the paper.
first consider a crystal with electrons moving around throughout its interior. Under certain conditions, it can be energetically favorable for these electrical charges to pile up in a regular,
repeating fashion inside the crystal, forming what is called a charge-ordered phase. The building block of this type of order, namely charge, is simply a scalar quantity--that is,
it can be described by just a numerical value, or magnitude. In addition to charge, electrons also have a degree of freedom known as spin.
When spins line up parallel to each other (in a crystal, for example), they form a ferromagnet--the type of magnet you might use on your refrigerator
and that is used in the strip on your credit card. Because spin has both a magnitude and a direction
a spin-ordered phase is described by a vector. Over the last several decades, physicists have developed sophisticated techniques to look for both of these types of phases.
if the building block of the ordered phase was a pair of oppositely pointing spins--one pointing north
When you shine a red laser pointer at a wall, for example, your eye detects red light. However, for all materials, there is a tiny amount of light bouncing off at integer multiples of the incoming frequency.
So with the red laser pointer, there will also be some blue light bouncing off of the wall.
The Hsieh group's experiment exploited the fact that changes in the symmetry of a crystal will affect the strength of each harmonic differently.
Since the emergence of multipolar ordering changes the symmetry of the crystal in a very specific way--a way that can be largely invisible to conventional probes--their idea was that the optical harmonic response of a crystal could serve as a fingerprint of multipolar order."
"We found that light reflected at the second harmonic frequency revealed a set of symmetries completely different from those of the known crystal structure,
Cuprates are the only family of materials known to exhibit superconductivity at high temperatures--exceeding 100 Kelvin(-173 degrees Celsius.
A high enough level of doping will transform cuprates into high-temperature superconductors, and as cuprates evolve from being insulators to superconductors, they first transition through a mysterious phase known as the pseudogap,
where an additional amount of energy is required to strip electrons out of the material. For decades, scientists have debated the origin of the pseudogap
and its relationship to superconductivity--whether it is a necessary precursor to superconductivity or a competing phase with a distinct set of symmetry properties.
If that relationship were understood better scientists believe, it might be possible to develop materials that superconduct at temperatures approaching room temperature.
and temperature window where the pseudogap is present. The researchers are still investigating whether the two overlap exactly,
but Hsieh says the work suggests a connection between multipolar order and pseudogap phenomena.""There is also very recent work by other groups showing signatures of superconductivity in Sr2iro4 of the same variety as that found in cuprates,
"he says.""Given the highly similar phenomenology of the iridates and cuprates, perhaps iridates will help us resolve some of the longstanding debates about the relationship between the pseudogap and high-temperature superconductivity."
"Hsieh says the finding emphasizes the importance of developing new tools to try to uncover new phenomena."
#On the road to ANG vehicles: Berkeley Lab researchers find a better way to store natural gas as a transportation fuel Researchers with the U s. Department of energy (DOE)' s Lawrence Berkeley National Laboratory (Berkeley Lab) have developed a variety
of metal-organic frameworks (MOFS)- sponge-like 3d crystals with an extraordinarily large internal surface area-that feature flexible gas-adsorbing pores.
which in turn has the potential to help make the driving range of an adsorbed-natural-gas (ANG) car comparable to that of a typical gasoline-powered car."
"Our flexible MOFS can be used to boost the usable capacity of natural gas in a tank,
reduce the heating effects associated with filling an ANG tank, and reduce the cooling effects upon discharging the gas from the ANG tank,
"says Jeffrey Long, a chemist with Berkeley Lab's Materials sciences Division and the University of California (UC) Berkeley who is leading this research."
"This ability to maximize the deliverable capacity of natural gas while also providing internal heat management during adsorption and desorption demonstrates a new concept in the storage of natural gas that provides a possible path forward for ANG applications where none was envisioned before."
"Long is the corresponding author of a Nature paper that describes this work entitled,"Methane storage in flexible metal-organic frameworks with intrinsic thermal management."
While compressed natural gas-fueled vehicles are already on the road, the widespread use of natural gas as a transportation fuel has been hampered by cumbersome and expensive onboard gas storage tanks and the cost of dispensing compressed natural gas to vehicles.
The storage issue is especially keen for light-duty vehicles such as cars, in which the space available for onboard fuel storage is limited.
ANG has the potential to store high densities of methane within a porous material at ambient temperature and moderate pressures
upon discharging the methane down to the minimum delivery pressure, much of it remains in the tank,
because the gas must force its way into the MOF crystal structure, opening and expanding the pores.
"In addition, Long says, the step in the adsorption isotherm is associated with a structural phase change in the MOF crystal that reduces the amount of heat released upon filling the tank,
when methane is delivered to accelerate the vehicle.""Crystallites that experience higher external pressures will have a greater free energy change associated with the phase transition
and will open at higher pressures, "Long says.""Our results present the prospect of using mechanical pressure,
Long says that it should be possible to design MOF adsorbents of methane with even stronger gas binding sites and higher energy phase transitions for next generation ANG vehicles.
and packing strategies should also allow further reductions to external thermal-management requirements and optimization of the overall natural gas storage system performance. c
#The world's fastest nanoscale photonics switch: Russian scientists developed the world's fastest nanoscale photonics switch This work belongs to the field of photonics-an optics discipline
which appeared in the 1960-s, simultaneously with the invention of lasers. Photonics has the same goals as electronics does,
but uses photons--the quanta of light--instead of electrons. The biggest advantage of using photons is the absence of interactions between them.
As a consequence, photons address the data transmission problem better than electrons. This property can primarily be used for in computing where IPS (instructions per second) is the main attribute to be maximized.
The typical scale of eletronic transistors--the basis of contemporary electronic devices--is less than 100 nanometers
wheres the typical scale of photonic transistors stays on the scale of several micrometers. Nanostructures that are able to compete with the electronic structures--for example,
plasmonic nanoparticles--are characterized by low efficiency and significant losses. Therefore, coming up with a compact photonic switch was a very challenging task.
Three years ago several groups of researchers simultaneously discovered an important effect: they found out that silicon nanoparticles are exhibit strong resonances in the visible spectrum-the so-called magnetic dipole resonances.
This type of resonance is characterized by strong localization of light waves on subwavelength scales, inside the nanoparticles.
This effect turned out to be interesting to researches, but, according to Maxim Shcherbakov, the first author of the article published in Nano Letters,
nobody thought that this discovery could create a basis for development of a compact and very rapid photonic switch.
Nanoparticles were fabricated in the Australian National University by e-beam lithography followed by plasma-phase etching.
who served an internship in the University as a part of Presidential scholarship for studying abroad.
and all the experimental work was carried out at the Faculty of physics of Lomonosov Moscow State university, in the Laboratory of Nanophotonics and Metamaterials."
"In our experimental research me and my colleague Polina Vabishchevich from the Faculty used a set of nonlinear optics methods that address femtosecond light-matter,
Switching speeds that fast will allow to create data transmission and processing devices that will work at tens and hundreds terabits per second.
This can make possible downloading thousands of HD-movies in less than a second. The operation of the all-optical switch created by MSU researchers is based on the interaction between two femtosecond pulses.
The interaction becomes possible due to the magnetic resonance of the silicon nanostructures. If the pulses arrive at the nanostructure simultaneously,
one of them interacts with the other and dampers it due to the effect of two-photon absorption.
and the second pulse goes through the nanostructure without changing.""We were able to develop a structure with the undesirable free-carrier effects are suppressed,
Our work represents an important step towards novel and efficient active photonic devices--transistors, logic units, and others.
Features of the technology implemented in our work will allow its use in silicon photonics. In the nearest future, we are going to test such nanoparticles in integrated circuits
#Magnetic Nanosorbents Eliminate Fluoride from Water Researchers from Tehran University of Medical sciences used low-cost and available raw materials for the laboratorial production of nanosorbents with high efficiency in elimination of fluoride from contaminated water.
Presence of high concentration of fluoride in water reservoirs, specially in drinking water, results in serious hygiene concerns.
Chitosan has been used as a sorbent in this research to eliminate fluoride from aqueous environments. However, since the separation of the sorbent from the solution is very difficult and costly
magnetic properties have been created in the structure of the sorbent by using iron oxide nanoparticles. The synthesized magnetic composite is separated from the solution phase in the presence of a magnetic field in a short time through this method.
Results showed that the synthesized composite can be used as an effective sorbent to purify water contaminated by fluoride due to its simple and quick separation, high efficiency and the lack of the creation of secondary pollution in the solution.
The composite can be reused even after five times of application and it can be recycled only by using acidic solution.
Chitosan used in this research has been extracted from shrimp shell. Among the most important advantages of the research
mention can be made of reducing pollution in surface or drinking water, reducing the cost of raw materials
and increasing the rate of separation of sorbents from the sorbed pollutants in the liquid phase e
In order to sharply capture motions of such particles during a reaction, one needs to work with"shutter speeds"in the range of femtoseconds
This way they generate an interference pattern at the detector from which an atomic 3d-structure of the examined substance is reconstructed.
the physicists applied their ultrashort electron pulses to a biomolecule in a diffraction experiment. It is planned to use those electron beams for pump-probe experiments:
#Silk could be new'green'material for next-generation batteries Lithium-ion batteries have enabled many of today electronics, from portable gadgets to electric cars.
But much to the frustration of consumers, none of these batteries last long without a recharge.
Now scientists report in the journal ACS Nano("Hierarchical Porous Nitrogen-Doped Carbon Nanosheets Derived from Silk for Ultrahigh-Capacity Battery Anodes and Supercapacitors")the development of a new,
reenway to boost the performance of these batteries with a material derived from silk. Chuanbao Cao and colleagues note that carbon is a key component in commercial Li-ion energy storage devices including batteries and supercapacitors.
Most commonly graphite fills that role, but it has limited a energy capacity. To improve the energy storage,
manufacturers are looking for an alternative material to replace graphite. Cao team wanted to see
if they could develop such a material using a sustainable source. The researchers found a way to process natural silk to create carbon-based nanosheets that could potentially be used in energy storage devices.
Their material stores five times more lithium than graphite can a capacity that is critical to improving battery performance.
It also worked for over 10,000 cycles with only a 9 percent loss in stability.
The researchers successfully incorporated their material in prototype batteries and supercapacitors in a one-step method that could easily be scaled up,
the researchers note h
#New metal-organic framework material captures carbon at half the energy cost UC Berkeley chemists have made a major leap forward in carbon-capture technology with a material that can
efficiently remove carbon from the ambient air of a submarine as readily as from the polluted emissions of a coal fired power plant.
The material then releases the carbon dioxide at lower temperatures than current carbon-capture materials, potentially cutting by half or more the energy currently consumed in the process.
The released CO2 can then be injected underground, a technique called sequestering, or, in the case of a submarine,
expelled into the sea.""Carbon dioxide is 15 percent of the gas coming off a power plant,
so a carbon-capture unit is going to be said big senior author Jeffrey Long, a UC Berkeley professor of chemistry and faculty senior scientist at Lawrence Berkeley National Laboratory."
"With these new materials, that unit could be much smaller, making the capital costs drop tremendously as well as the operating costs."
"The material, a metal-organic framework (MOF) modified with nitrogen compounds called diamines, can be tuned to remove carbon dioxide from the room-temperature air of a submarine, for example,
or the 100-Degree fahrenheit) flue gases from a power plant.""It would work great on something like the International space station,
"Long said. Diamine-Appended Metal-Organic Frameworks The diamine-appended metal-organic framework before and after binding of carbon dioxide.
The view is a cross section through one of the pores of the MOF, showing diamine molecules (containing blue nitrogen atoms) attached to metal (manganese) atoms (green).
Graphic by Thomas Mcdonald, Jarad Mason, Jeffrey Long/UC Berkeley) Though power plants are required not now to capture carbon dioxide from their emissions,
in order to slow the pace of climate change caused by fossil-fuel burning. If the planet's CO2 levels rise much higher than they are today,
"From flue gas to submarines Power plants that capture CO2 today use an old technology whereby flue gases are bubbled through organic amines in water, where the carbon dioxide binds to amines.
the process also saves the huge energy costs of heating the water in which amines are dissolved.
MOFS are composites of metals--in this case magnesium or manganese--with organic compounds that, together, form a porous structure with microscopic, parallel channels.
Several years ago, Long and his lab colleagues developed a way to attach amines to the metals in an MOF to produce pores of sufficient diameter to allow CO2 to penetrate rapidly into the material.
UC Berkeley graduate students Thomas Mcdonald and Jarad Mason, together with other co-workers, describe how this works."
The pressure at which CO2 binds to the amines can be adjusted by changing the metal in the MOF.
and policy-makers in many countries hope to reduce this below 350 ppm to avoid the most severe impacts of climate change, from increasingly severe weather events and sea level rise to global average temperature increases of 10 degrees Fahrenheit.'
to use the new technology to radically reduce the cost of chemical separations, with plans in the works for a pilot study of CO2 separation from power plant emissions.
"We're also hoping to develop something that might be tested in a submarine, "Long said.
which produce emissions containing about 5 percent CO2, to the higher concentrations of coal fired power plants.""We got lucky,
says MIT aeronautics and astronautics alumna Natalya Brikner Phd 5, cofounder and CEO of Accion Systems. ou can make a satellite the size of a softball with a surprising amount of capabilities,
Now Accion has developed a commercial electrospray propulsion system their first is about the size of a pack of gum made of tiny chips that provide thrust for small satellites.
an associate professor of aeronautics and astronautics who invented the underlying technology. Ultimately, he adds, the technology could give small startups and even countries without well-funded space programs the opportunity to use low-cost satellites for space exploration. t
a module comprising eight chips each about 1 square centimeter, and 2 millimeters thick that can be applied anywhere on a satellite.
The module has a plastic tank that stores a nontoxic nonvolatile, liquid-salt propellant. Above the reservoir are the chips,
which each have a porous substrate with about 500 pointed tips and, above that, an extractor grid with small holes.
Capillary forces cause the propellant to flow from the reservoir to the substrate tips. When a high voltage is applied between the tips and grid,
charged ions burst through the holes. hen you extract and accelerate these ions, that momentum exchange propels the spacecraft in the opposite direction,
Because the module doesn have pressurized tanks, bulky valves, or neutralizing cathodes, it has a higher thrust-to-mass ratio than low-power,
plasma-based ion engines meaning it packs a Punch in January, Accion tested a miniature version of MAX-1,
called MIN-0, inside a vacuum chamber at MIT. The team measured the emitted current of the released ions after applying certain levels of voltage.
Chemical systems are made with explosive pressurized tanks, which are allowed not to piggyback on the larger rockets that carry small satellites into space. o theye easy to produce,
Accion propellant is a liquid salt material, similar in structure to common table salt, which can be made in large quantities.
and a simple design, Accion can batch-manufacture modules much like computer chips in quantities of around 200 at once.
and obtaining funding. Entrepreneurs-in-residence at the Martin Trust Center for MIT Entrepreneurship helped them work through mistakes they made regarding legal support, funding,
and operations. e had a lot of holes to dig out of, and they were helpful, Brikner says.
#Chameleon-like artificial'skin'shifts color on demand Borrowing a trick from nature, engineers from the University of California at Berkeley have created an incredibly thin,
This new material-of-many-colors offers intriguing possibilities for an entirely new class of display technologies, color-shifting camouflage,
and sensors that can detect otherwise imperceptible defects in buildings, bridges, and aircraft.""This is the first time anybody has made a flexible chameleon-like skin that can change color simply by flexing it,
Developed by engineers from the University of California at Berkeley, this chameleon-like artificial skin"changes color as a minute amount of force is applied.
and other natural substances occur when white, broad spectrum light strikes their surfaces. The unique chemical composition of each surface then absorbs various bands,
such as the leaves on the trees in autumn, requires a change in chemical make-up. Recently, engineers and scientists have been exploring another approach,
one that would create designer colors without the use of chemical dyes and pigments. Rather than controlling the chemical composition of a material,
and beetles to create a particularly iridescent display of color. Controlling light with structures rather than traditional optics is not new.
The Berkeley researchers were able to overcome both these hurdles by forming their grating bars using a semiconductor layer of silicon approximately 120 nanometers thick.
Its flexibility was imparted by embedding the silicon bars into a flexible layer of silicone. As the silicone was bent
or flexed, the period of the grating spacings responded in kind. The semiconductor material also allowed the team to create a skin that was incredibly thin, perfectly flat,
and easy to manufacture with the desired surface properties. This produces materials that reflect precise and very pure colors
Their initial design, subjected to a change in period of a mere 25 nanometers, created brilliant colors that could be shifted from green to yellow,
orange, and red-across a 39-nanometer range of wavelengths. Future designs, the researchers believe,
"For consumers, this chameleon material could be used in a new class of display technologies, adding brilliant color presentations to outdoor entertainment venues.
It also may be possible to create an active camouflage on the exterior of vehicles that would change color to better match the surrounding environment.
More day-to-day applications could include sensors that would change color to indicate that structural fatigue was stressing critical components on bridges, buildings,
#3d printer for small molecules opens access to customized chemistry Howard hughes medical institute scientists have simplified the chemical synthesis of small molecules,
eliminating a major bottleneck that limits the exploration of a class of compounds offering tremendous potential for medicine and technology.
an HHMI early career scientist at the University of Illinois at Urbana-Champaign, used a single automated process to synthesize 14 distinct classes of small molecules from a common set of building blocks.
Burke's team envisions expanding the approach to enable the production of thousands of potentially useful molecules with a single machine
Their work is described in the March 13, 2015, issue of the journal Science. According to Burke, the highly customized approach that chemists have relied long on to synthesize small molecules is time consuming and inaccessible to most researchers. lot of great medicines have not been discovered yet because of this synthesis bottleneck,
he says. With his new technology, Burke aims to change that. he vision is that anybody could go to a website,
pick the building blocks they want, instruct their assembly through the web, and the small molecules would get synthesized and shipped,
Burke says. e're not there yet, but we now have an actionable roadmap toward on-demand small-molecule synthesis for non-specialists.
Nature produces an abundance of small molecules, and scientists have adapted already many of them for practical applications.
as are many important biological research tools. A wide-range of technologies, including LEDS, diagnostic tools,
and solar cells also rely on small molecules. mall molecules have had already a big impact on the world,
says Burke. ut we've barely touched the surface of what they're capable of achieving.
Furthermore, it requires expertise. urrently you have to have a high degree of training in synthesis to make small molecules,
In his research, Burke has been exploring the potential of small molecules to treat disease. Plants
Burke says. oing real atomistic modifications to transform nature's starting points into actual medicines is really,
Burke says. here are a small number of building blocks that are coupled together over and over again, using the same kind of chemistry in an iterative fashion.
patterns emerged. here are building blocks that appear over and over again, and we've been able to dissect out the building blocks that are most common,
he says. The small-molecule synthesizer that Burke's team built takes these building blocks each with two chemical connectors that can be linked readily to the corresponding part on another building block
--and snaps them together like pop beads using a standard chemical reaction. The team used the approach to synthesize 14 different small molecules,
Burke's team has developed hundreds of these chemical building blocks and made them commercially available. ut it's not really about the numbers,
he says. e are showing that with a very reasonable number of building blocks we can make many different types of natural products.
meaning the atom-by-atom modifications that researchers need to optimize these molecules into therapeutic compounds
He has founded a company, REVOLUTION Medicines, to use and continue to develop the technology for this purpose.
engineers, medical doctors, and even the public to produce small molecules. hen you put the power to manufacture into the hands of everyone,
when non-experts start to use technology that used to only be in the hands of a select few
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