General science advances thread

Single-step process simplifies development of new materials

21 December 2012

A multidisciplinary team has developed a low-temperature process that removes complex, time-consuming steps from the development of new materials.

The team at the University of Texas at Austin’s Cockrell School of Engineering is using microwave energy to assemble atoms into thin films and is growing them directly onto a substrate at significantly low temperatures.

Results of the team’s research, conducted under the supervision of Prof Arumugam Manthiram of the Texas Materials Institute and the Department of Mechanical Engineering and Prof Ali Yilmaz of the Department of Electrical and Computer Engineering, were published in the 19 December issue of Scientific Reports.

‘Lowering the temperature at which thin films of relevant materials can be grown is one of the key focus areas of our research,’ said Reeja Jayan, postdoctoral fellow at the University of Texas at Austin and one of the lead authors of the paper. ‘With our microwave process, we could bring down temperatures to the level that enables us to grow materials on heat-sensitive surfaces, such as plastics, without damaging them.’

The conventional methods for growing thin films typically require temperatures of more than 450ºC for several hours and a cumbersome multi-step process.

With the new method, thin films can now be grown at temperatures as low as 150ºC in less than 30 minutes, in a single-step process, by using microwaves.


‘With this new method, the process of thin-film growth is made simple, wherein a solution containing the atoms of the desired material, together with the substrate, when exposed to microwaves can result in controlled film growth,’ said Manthiram in a statement. ‘Applications that could utilise this process include developing thin-film batteries and solar cells that could be integrated into various devices such as cell phones and tablets.’

Read more: Single-step process simplifies development of new materials | News | The Engineer
 
Flexible, light solar cells: Researchers develop a new approach using graphene sheets coated with nanowires
December 21, 2012 by David L. Chandler

Flexible, light solar cells: Researchers develop a new approach using graphene sheets coated with nanowires
MIT researchers have produced a new kind of photovoltaic cell based on sheets of flexible graphene coated with a layer of nanowires. The approach could lead to low-cost, transparent and flexible solar cells that could be deployed on windows, roofs or other surfaces. The new approach is detailed in a report published in the journal Nano Letters, co-authored by MIT postdocs Hyesung Park and Sehoon Chang, associate professor of materials science and engineering Silvija Gradečak, and eight other MIT researchers.

While most of today's solar cells are made of silicon, these remain expensive because the silicon is generally highly purified and then made into crystals that are sliced thin. Many researchers are exploring alternatives, such as nanostructured or hybrid solar cells; indium tin oxide (ITO) is used as a transparent electrode in these new solar cells.

"Currently, ITO is the material of choice for transparent electrodes," Gradečak says, such as in the touch screens now used on smartphones. But the indium used in that compound is expensive, while graphene is made from ubiquitous carbon.
 
Researchers develop a biological concrete for constructing 'living' facades with lichens, mosses, other microorganism
December 21, 2012

The Structural Technology Group at the Polytechnic University of Catalonia has developed and patented a type of biological concrete that supports the natural, accelerated growth of pigmented organisms. The material, which has been designed for the façades of buildings or other constructions in Mediterranean climates, offers environmental, thermal and aesthetic advantages over other similar construction solutions.

In studying this concrete, the researchers at the Structural Technology Group of the Universitat Politècnica de Catalunya, BarcelonaTech (UPC) have focused on two cement-based materials. The first of these is conventional carbonated concrete (based on Portland cement), with which they can obtain a material with a pH of around 8. The second material is manufactured with a magnesium phosphate cement (MPC), a hydraulic conglomerate that does not require any treatment to reduce its pH, since it is slightly acidic.

On account of its quick setting properties, magnesium phosphate cement has been used in the past as a repair material. It has also been employed as a biocement in the field of medicine and dentistry, indicating that it does not have an additional environmental impact.

Researchers develop a biological concrete for constructing 'living' facades with lichens, mosses, other microorganism
 
Rheinmetall's 50kW high-energy laser weapon successfully passes tests
Rheinmetall's 50kW high-energy laser weapon successfully passes tests

Practical high-energy laser weapons came a step closer to reality in November as Rheinmetall tested its new 50 kW high-energy weapon laser demonstrator. The series of exercises took place at the German-based group’s Ochsenboden Proving Ground in Switzerland. There the 50 kW laser weapon was tested against a series of targets to show the improvements over last year’s 10 kW version.

Designed for air defense, asymmetric warfare and Counter Rocket, Artillery, Mortar (C-RAM) operations, the Rheinmetall laser isn't a single weapon, but two laser modules mounted on Oerlikon Revolver Gun air defense turrets with additional modules for the power supply. The lasers are combined using Rheinmetall's Beam Superimposing Technology (BST) to focus a 30 kW and a 20 kW laser on the same spot. This gives it the destructive power of a single 50 kW laser. The company says that a future 100 kW laser weapon is entirely feasible.
 
Magnetically levitating graphite can be moved with laser

Magnetic levitation has been demonstrated for a variety of objects, from trains to frogs, but so far no one has developed a practical maglev-based actuator that converts some external source of energy into motion. Now in a new study, researchers for the first time have used a laser to control the motion of a magnetically levitating graphite disk. By changing the disk's temperature, the laser can change the disk's levitation height and move it in a controlled direction, which has the potential to be scaled up and used as a light-driven human transportation system. Laser light or sunlight can also cause the levitating disk to rotate at over 200 rpm, which could lead to a new type of light energy conversion system.

The researchers predict that the ability to control maglev-based motion with a laser could lead to the development of maglev-based actuators and photothermal solar energy conversion systems. Applications could include a low-cost, environmentally friendly power generation system and a new type of light-driven transportation system.

"As for the actuator, the maglev graphite can convey anything that has almost the same weight as the levitating graphite disk. So, if the scale expansion of the photo-actuator system is achieved, it is not a dream that a human on the maglev graphite can drive himself."
Read more at: Magnetically levitating graphite can be moved with laser
 
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China opens the longest high-speed rail route in the world

China's capital Beijing is now linked to Guangzhou in the south by a 1,436 mile (2,298 km) high speed rail route.

China opens the longest high-speed rail route in the world
This dwarfs the 819 mile (1,318 km) route between Beijing and Shanghai which opened in June 2011. The new line is described by officials as "one of the most technically advanced in the world" and will cut the previously 20-hour journey to just 8 hours. It has a total of 35 stops, with trains running at 186 mph (300 km/h), although the line is designed to accommodate future speeds of up to 220 mph (350 km/h). The route will be extended to Hong Kong by 2015.

China already has the world's biggest high speed rail (HSR) network, covering over 5,800 miles (9,300 km) of routes. As it continues to grow and become more developed, the country has even bigger ambitions. With $300 billion of investment between 2010 and 2020, it will construct over 11,000 miles (17,600 km) of new HSR lines, reaching 5 billion journeys per year and giving 90% of its population access to the network.

Trains are also being developed for other lines that could eventually travel at 625 mph (1,000 km/h), shattering previous speed records. These would use vacuum tubes which avoid the problem of heat from air friction.
 
Hyundai tests NFC tech to bring phones and cars closer together


Smartphones and cars have been coming together for some time now, but Hyundai is moving experimentation forward with its new "Connectivity Concept." The basis of the concept is using NFC tags attached to a car, allowing the driver to swipe their phone over the tag to unlock the car and perform other functions.

Hyundai revealed the new technology at its headquarters in Germany and calls the project a "technology study."

Not only does the phone use Near Field Communication (NFC) — or short-range electronic transmissions to unlock doors wirelessly, and even starts the car before the driver enters. Once inside, the phone docs in the center console and synchs it with the seven-inch onboard infotainment touchscreen.

Hyundai has tested the Connectivity Concept on the European model i30. When docked in the console the phone streams music, accesses the users' phonebook, text-messaging, remembers preferences such as radio presets and more. Plus, like other docking systems while the phone is doing its thing, it's also wirelessly charging.
Hyundai tests NFC tech to bring phones and cars closer together | DVICE
 
New thermoelectric material sucks electricity out of hot water

When humans produce energy, we do it very inefficiently. Usually what happens is that we make something very hot (like a car engine), use a tiny bit of that energy to do work, and then spend even more energy getting rid of all the waste heat. Panasonic has developed a new thermoelectric material that can get a chunk of that energy back.

A thermoelectric material is something that can convert heat directly into electricity. It's not a new thing, but generally it's so inefficient that anyone who's serious about capturing electricity through heat instead uses some sort of steam generator. Where thermoelectrics have potential is in microgenerators, where you're just looking for a little bit of power to take the edge off of your electricity bill.

Panasonic's new thermoelectric material can suck 2.5 watts of electricity out of hot water running through a 10 centimeter section of pipe. Four pipes put together gets you about 10 watts, which is enough to power a light bulb. Nothing is free, of course, and this material is really just harvesting energy from whatever energy source you used to heat up your water in the first place. But losing energy from hot water is something that happens anyway, and the difference here is that instead of losing that energy out into the environment, it's being reclaimed (to some extent) by the thermoelectric material instead. It's also important to keep in mind that this stuff doesn't just require a source of hot water; since it operates based on a temperature differential, it needs cold water as well, along with (long term) a pump to keep the cold water circulating.
New thermoelectric material sucks electricity out of hot water | DVICE
 
Not a Blimp, Not a Plane: The Gigantic Aeroscraft Is Ready, and It’s Awesome


Jesus Diaz
Not a Blimp, Not a Plane: The Gigantic Aeroscraft Is Ready, and It's Awesome

This is a new type of rigid aircraft. It's not a blimp, and it's not an airplane, but this thing has the potential to alter the way we understand travel and completely change military transportation. You can see a video of its first move here.

According to the company, "the final configuration and vehicle systems integration functionality testing has been completed as the Aeroscraft subscale demonstration vehicle reaches the finish line." The aircraft will enter a flying tests phase over the next 60 days. After they are done with the testing, they will build the full scale version. Yes, this gigantic aircraft is only a small version of what's coming. Imagine that.

Aeros CEO Igor Pasternak thinks that "this is truly the beginning of a vertical global transportation solution for perhaps the next 100 years." Indeed, it may become just that. Imagine having the capability of transporting huge amounts of material or people across any distance, without the need of any ground infrastructure.
 
Quantum gas goes below absolute zero - Ultracold atoms pave way for negative-Kelvin materials.
Nature News ^ | 03 January 2013 | Zeeya Merali

Quantum gas goes below absolute zero : Nature News & Comment

It may sound less likely than hell freezing over, but physicists have created an atomic gas with a sub-absolute-zero temperature for the first time1. Their technique opens the door to generating negative-Kelvin materials and new quantum devices, and it could even help to solve a cosmological mystery.

Lord Kelvin defined the absolute temperature scale in the mid-1800s in such a way that nothing could be colder than absolute zero. Physicists later realized that the absolute temperature of a gas is related to the average energy of its particles. Absolute zero corresponds to the theoretical state in which particles have no energy at all, and higher temperatures correspond to higher average energies.

However, by the 1950s, physicists working with more exotic systems began to realise that this isn't always true: Technically, you read off the temperature of a system from a graph that plots the probabilities of its particles being found with certain energies. Normally, most particles have average or near-average energies, with only a few particles zipping around at higher energies. In theory, if the situation is reversed, with more particles having higher, rather than lower, energies, the plot would flip over and the sign of the temperature would change from a positive to a negative absolute temperature, explains Ulrich Schneider, a physicist at the Ludwig Maximilian University in Munich, Germany.

Peaks and valleys

Schneider and his colleagues reached such sub-absolute-zero temperatures with an ultracold quantum gas made up of potassium atoms. Using lasers and magnetic fields, they kept the individual atoms in a lattice arrangement. At positive temperatures, the atoms repel, making the configuration stable. The team then quickly adjusted the magnetic fields, causing the atoms to attract rather than repel each other. “This suddenly shifts the atoms from their most stable, lowest-energy state to the highest possible energy...”..

Wolfgang Ketterle, a physicist and Nobel laureate at the Massachusetts Institute of Technology in Cambridge, who has previously demonstrated negative absolute temperatures in a magnetic system2, calls the latest work an “experimental tour de force”. Exotic high-energy states that are hard to generate in the laboratory at positive temperatures become stable at negative absolute temperatures — “as though you can stand a pyramid on its head and not worry about it toppling over,” he notes — and so such techniques can allow these states to be studied in detail. “This may be a way to create new forms of matter in the laboratory,” Ketterle adds.

If built, such systems would behave in strange ways, says Achim Rosch, a theoretical physicist at the University of Cologne in Germany, who proposed the technique used by Schneider and his team3. For instance, Rosch and his colleagues have calculated that whereas clouds of atoms would normally be pulled downwards by gravity, if part of the cloud is at a negative absolute temperature, some atoms will move upwards, apparently defying gravity4.

Another peculiarity of the sub-absolute-zero gas is that it mimics 'dark energy', the mysterious force that pushes the Universe to expand at an ever-faster rate against the inward pull of gravity. Schneider notes that the attractive atoms in the gas produced by the team also want to collapse inwards, but do not because the negative absolute temperature stabilises them. “It’s interesting that this weird feature pops up in the Universe and also in the lab,” he says. “This may be something that cosmologists should look at more closely.”
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Weird...
 
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New antimatter method to provide 'a major experimental advantage'

Researchers have proposed a method for cooling trapped antihydrogen which could offer 'a major experimental advantage' and help to map the mysterious properties of antimatter that have to date remained elusive.
New antimatter method to provide 'a major experimental advantage'


The new method, developed by a group of researchers from the USA and Canada, could potentially cool trapped antihydrogen atoms to temperatures 25 times colder than already achieved, making them much more stable and a lot easier to experiment on.

The suggested method, which is published today in the Journal of Physics B: Atomic, Molecular and Optical Physics, involves a laser, directed at antihydrogen atoms to give them a 'kick', causing them to lose energy and cool down.

Antihydrogen atoms are formed in an ultra-high vacuum trap by injecting antiprotons into positron plasma. An atomic process causes the antiproton to capture a positron which gives an electronically excited antihydrogen atom.

Typically, the antihydrogen atoms have a lot of energy compared to the trapping depth which can distort the measurements of their properties. As it is only possible to trap very few antihydrogen atoms, the main method for reducing the high energies is to laser cool the atoms to extremely low temperatures.

In the future, antimatter could be used as a fuel for interplanetary travel – or even interstellar travel – as part of antimatter catalysed nuclear pulse propulsion, or other antimatter-based rocketry such as the redshift rocket. Since the energy density of antimatter is much higher than that of conventional fuels, an antimatter fueled spacecraft would have a higher thrust-to-weight ratio than a conventional spacecraft.

At a recent presentation with NASA's Future In-Space Operations working group, an expert claimed that such technology may be possible within 50 or 60 years. Spacecraft could reach Jupiter within four months, potentially opening up parts of the outer Solar System to manned exploration.

I want a anti-matter engine capable of getting us from earth to mars in 2 months.
 
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German Military Laser Destroys Targets Over 1Km Away

A German company has brought us one step closer to the kinds of shootouts only seen in Sci-Fi films. Düsseldorf-based Rheinmetall Defense recently tested a 50kW, high-energy laser at their proving ground facility in Switzerland. According to the company, the laser passed the test with “flying colours.”

The system isn’t actually a single laser but two laser modules mounted onto Revolver Gun air defense turrets made by Oerlikon and attached to additional power modules. The laser modules are 30 kW and 20 kW, but a Beam Superimposing Technology (BST) combines two lasers to focus in a “superimposed, cumulative manner” that wreaks havoc on its targets.

First, the system sliced through a 15mm- (~0.6 inches) thick steel girder from a kilometer away. Then, from a distance of two kilometers, it shot down a handful of drones as they nose-dived toward the surface at 50 meters per second. The laser’s radar, a widely used system called Skyguard, was capable of tracking the drones through their descent up to three kilometers away

The glass here isn't made in the same way as vases and juice tumblers are. Glassware for the home is made by cooling molten glass into a solid shape. But Mark Ediger, a chemist at the University of Wisconsin-Madison who worked with de Pablo, built the new glass by heating it to a molten form and then a vapor, then letting the vapor settle layer by layer onto a hard surface. The result was a denser, stronger material that withstands higher temperatures than conventionally made glass does.
http://www.technewsdaily.com/16254-creating-durable-aged-glass.html
 
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Clear Improvement: New Glass Could Last Millennia
TechNewsDaily StaffJanuary 07 2013 02:59 PM ET
Clear Improvement: New Glass Could Last Millennia | TechNewsDaily.com
An unusual way of making glass could create glassy materials as durable as amber — which is considered a glasslike material — that's been around for thousands of years, a new study has found. In other words, researchers have figured out a way to make new glass act just like aged glass.

Knowing how to make ultra-stable, aged glass could help researchers make stronger metals, according to a statement from the University of Chicago, where the lead study scientist, Juan de Pablo, is a professor of molecular engineering. Stable glass-making techniques could also make drugs that, like super-stable glass, don't have crystals in their molecular structure and therefore dissolve more quickly in the body.

The glass here isn't made in the same way as vases and juice tumblers are. Glassware

Knowing how to make ultra-stable, aged glass could help researchers make stronger metals, according to a statement from the University of Chicago, where the lead study scientist, Juan de Pablo, is a professor of molecular engineering. Stable glass-making techniques could also make drugs that, like super-stable glass, don't have crystals in their molecular structure and therefore dissolve more quickly in the body.

The glass here isn't made in the same way as vases and juice tumblers are. Glassware for the home is made by cooling molten glass into a solid shape. But Mark Ediger, a chemist at the University of Wisconsin-Madison who worked with de Pablo, built the new glass by heating it to a molten form and then a vapor, then letting the vapor settle layer by layer onto a hard surface. The result was a denser, stronger material that withstands higher temperatures than conventionally made glass does. [SEE ALSO: New Self-Cleaning Glass Avoids Fogging, Glare]
 
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:tongue:



'Tricorder' invention could put medical diagnosis and terrorism prevention in the palm of the hand

Published: Tuesday, January 8, 2013 - 14:03 in Physics & Chemistry

The hand-held scanners, or tricorders, of the Star Trek movies and television series are one step closer to reality now that a University of Missouri engineering team has invented a compact source of X-rays and other forms of radiation. The radiation source, which is the size of a stick of gum, could be used to create inexpensive and portable X-ray scanners for use by doctors, as well as to fight terrorism and aid exploration on this planet and others. "Currently, X-ray machines are huge and require tremendous amounts of electricity," said Scott Kovaleski, associate professor of electrical and computer engineering at MU. "In approximately three years, we could have a prototype hand-held X-ray scanner using our invention. The cell-phone-sized device could improve medical services in remote and impoverished regions and reduce health care expenses everywhere."

Kovaleski suggested other uses for the device. In dentists' offices, the tiny X-ray generators could be used to take images from the inside of the mouth shooting the rays outward, reducing radiation exposure to the rest of the patients' heads. At ports and border crossings, portable scanners could search cargoes for contraband, which would both reduce costs and improve security. Interplanetary probes, like the Curiosity rover, could be equipped with the compact sensors, which otherwise would require too much energy.

'Tricorder' invention could put medical diagnosis and terrorism prevention in the palm of the hand | e! Science News
 
Another tiny miracle: Graphene oxide soaks up radioactive waste
January 8, 2013

A new method for removing radioactive material from solutions is the result of collaboration between Rice University and Lomonosov Moscow State University. The vial at left holds microscopic particles of graphene oxide in a solution. At right, graphene oxide is added to simulated nuclear waste, which quickly clumps for easy removal. Credit: Anna Yu. Romanchuk/Lomonosov Moscow State University

(Phys.org)—Graphene oxide has a remarkable ability to quickly remove radioactive material from contaminated water, researchers at Rice University and Lomonosov Moscow State University have found
Another tiny miracle: Graphene oxide soaks up radioactive waste
 
Chips that can steer light
January 9, 2013 1:18 pm | by Larry Hardesty, MIT News Office | News |
Researchers from Massachusetts Institute of Technology have developed a 4,096-emitter array that fits on a single silicon chip. Chips that can steer beams of light could enable a wide range of applications, including cheaper, more efficient, and smaller laser rangefinders; medical-imaging devices that can be threaded through tiny blood vessels; and even holographic televisions that emit different information when seen from different viewing angles.
Chips that can steer light | News | R&D Magazine
 
Molecular machines could lead to more efficient manufacturing

10 January 2013 | By Stephen Harris


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Materials built by molecule-sized machines have moved a step closer to reality thanks to research at Manchester University.

A group of scientists led by Prof David Leigh have developed what they claim is the world’s most complex synthetic molecular machine, one that can build other molecules in a similar way to how biological compounds such as proteins and DNA are created.

The work, published today in a paper in the journal Science, could lead to the creation of molecular machines that automatically synthesise materials without the need for a complex process of chemical reactions, or even help create entirely new materials.

Molecular machines are complex arrangements of atoms that are designed to react with and manipulate other molecules, driven by the natural random movement of particles.

‘What people have done up to now is make molecular machines that can do very simple tasks like switch between different states and even do a limited amount of mechanical work, pull things a very small distance and so on,’ Leigh told The Engineer.

‘What we’ve come up with is a molecular machine that’s able to build other molecules and that’s not been done before.’

Read more: Molecular machines could lead to more efficient manufacturing | News | The Engineer
 

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