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Science & Technology News (638)

Controlling Crystal Structures with Additive Manufacturing Process

Category: Science & Technology
Posted: October 21, 2014 02:16PM
Author: Guest_Jim_*

Many believe that there will be a new renaissance of sorts in the near future, thanks to 3D printing. Additive manufacturing in general opens up some interesting doors at it allows for the precise construction of objects, with potentially little waste. Now researchers at Oak Ridge National Laboratory have found a way to control the crystal structure of a material using an additive manufacturing system.

To achieve this control, the researchers had to precisely manage the electron beam from an ARCAM electron beam melting system. This system works by fusing layers of metal powder together using an electron beam. In this case, it was a nickel-based part they were creating.

Many properties of a material are influenced by its microstructure, so this work could have some very powerful implications. Microelectronics to jet engine components could all have their characteristics tailored to achieve the performance desired.

Source: Oak Ridge National Laboratory

Novel Laser Tractor Beam Designed

Category: Science & Technology
Posted: October 21, 2014 09:44AM
Author: Guest_Jim_*

Though perhaps not as lauded as some science fiction technologies, tractor beams are still somewhat common in the genre. They are also among the sci-fi technologies that can or do exist, in one form or another. Researchers at the Australian National University have recently developed a laser tractor beam that operates on a different principle than most, allowing it to actually reverse its effects.

Normally a laser-based tractor beam uses the momentum of photons to move the particles they target. This design however uses the laser beam to selectively heat the target particle. That heat then causes air molecules to warm and move away from the surface, forcing the particle to recoil. By moving the hotspot on the particle, the researchers are able to change how the particle moves, potentially having to reverse direction.

As this design uses only a single laser, it is somewhat versatile and could find some interesting applications. These include capturing particles, including pollution, from the air or retrieving other particles for sampling purposes.

Source: Australian National University

Internet Usage Mapped Over the Course of a Day

Category: Science & Technology
Posted: October 21, 2014 05:43AM
Author: Guest_Jim_*

For many of us, the Internet is likely always available, except during an outage. To better understand the Internet and recognize outages, researchers at the University of Southern California tracked Internet usage across the planet for two months. From this data, they created a map that shows the Internet sleeping, as it were.

To collect the data, the research pinged 3.7 million IP address blocks, which would be around 950 million individual addresses, every 11 minutes for two months. This allowed them to establish a baseline for Internet usage and then track its use through the day. In the most developed areas, such as the United States and Europe, usage appeared constant as the routers we use to connect are always on. In less developed and wealthy nations however, usage will fluctuate.

The plan for this research is to help scientists and policymakers understand the normal operation of the Internet. With this information, normal downtimes may not be misidentified as outages and be able to predict how networking policies can influence network usage.



Source: University of Southern California

New Superconducting Circuit Designed

Category: Science & Technology
Posted: October 20, 2014 02:12PM
Author: Guest_Jim_*

Superconductivity is an interesting phenomenon that could have many applications from power lines to computer circuits. Exactly how a superconducting circuit would take shape though is still being determined. Researchers at MIT have recently developed and tested one circuit design that could make superconducting circuits cheaper and easier to produce.

Josephon junctions are a kind of superconducting circuit that have been able to reach 770 GHz, but while they do have great potential, they are hard to make and hard to work with. The new design from MIT is called a nanocryotron, or nTron, and would be much simpler to create as it consists of nanowires forming a T shape. Where the base meets the crossbar though, the base tapers down to a point. When an electrical current is applied to the base, the point causes electrons to bounce off of each other, producing enough heat to warm the crossbar past its critical temperature. This ends the conductivity of the crossbar, until it is cooled again, and thus acts as an electrical switch. This design does have limitations though, such as likely never surpassing 1 GHz, but being simpler to create, working with currents similar to those in other hardware, and an impedance that matches that of mRAM may still make it very useful.

As superconductors can carry a current without resistance, they can work with a percent the energy needed by modern electronics. Of course the liquid-helium cooling system would cut into some of that savings, but it could still be a net improvement.

Source: MIT

Replacement for Rare Earth Elements in LEDs Developed

Category: Science & Technology
Posted: October 20, 2014 09:16AM
Author: Guest_Jim_*

Light emitting diodes for home lighting have been growing in popularity of late, thanks to their efficiency and long lives. One problem they possess though is cost, and that problem may get worse in the future. Rare earth elements are needed for LEDs and many other technologies, and as the supply shrinks, costs will increase, unless someone does something about it.

As reported in the Journal of the American Chemical Society, researchers have developed an alternative to the rare earth elements in LEDs that is instead based on copper iodide. This material is much more abundant and can still be tuned to produce a variety of colors, including white. The white light the researchers were able to make was also warmer than that typical white LEDs emit.

Source: American Chemical Society

Interactive Typewriter Created

Category: Science & Technology
Posted: October 20, 2014 05:56AM
Author: Guest_Jim_*

It can be weird to think of the number of technologies that future generations may never encounter, and one of these will likely be the typewriter. With computers and word processors, it would seem like typewriters no longer serve a purpose. With some imagination and creativity though, a student at the University of Plymouth has resurrected a typewriter and connected it to the Internet.

It was not an easy task, as some parts had to be built and supplied by a German company, but it was a fun project, according to the 22-year-old student. The typewriter, called Dico, can tell when someone is approaching it using ultrasound, and will then connect to a random person on an Internet chat service. Using micro-controllers and solenoids, messages can be received and typed onto the paper to be read, though sometimes it will be encrypted. This was intentional, to cause the user to think about online security.

The student would like to refine Dico some more and may even build another, so the pair can talk to each other. This is not the only time he has converted older technology into something new and interesting, as he gave the 1950s short wave radio the ability to create small poems from people's brain activity.

Source: University of Plymouth

New Magnetic Mirror Created

Category: Science & Technology
Posted: October 17, 2014 12:31PM
Author: Guest_Jim_*

Mirrors are fairly common and useful objects, but do you know how they work? When light, electromagnetic radiation strikes a mirror, it interacts with the electrical component, causing the reflection to have the reverse electric field. Though not possible naturally, metamaterials can allow for magnetic mirrors that reflect the magnetic component, and, as reported in The Optical Society's Optica journal, a new design has been developed.

The reason metamaterials are required for a magnetic mirror has to do with the fact that magnetic fields interact with charged particles, but light has no charge. The first metamaterials to achieve magnetic mirroring only worked on long microwave frequencies. More recent designs using 'fish-scale' shaped metallic components allow for shorter wavelengths, but have considerable signal loss and are very dependent on the components' particular shapes. The new design addresses these issues by using a 2D array of non-metallic dielectric resonators. These resonators interact strongly with the magnetic component of light and, being made out of tellurium, have a low signal loss compared to their metallic counterparts.

Among the reasons magnetic mirrors would be useful is that traditional mirrors reversing the electric components of light, causes that component to cancel out, at the surface. This prevents nanoscale antennas and quantum dots from interacting with the light. By preserving the electric component, a magnetic mirror would allow for the maximum absorption of the light, and new technologies.

Source: The Optical Society

World's Thinnest Electric Generator Created

Category: Science & Technology
Posted: October 17, 2014 05:42AM
Author: Guest_Jim_*

More many modern technologies, thin is in, but this example may be a bit extreme. Researchers at Columbia University and the Georgia Institute of Technology have discovered a 2D material that exhibits the piezoelectric effect. This effect links mechanical deformation to the creation of electrical voltages.

Molybdenum disulfide (MoS2) is part of a family of materials known as transition metal dichalcogenides, which are 2D semiconductors. In theory, they can all be piezoelectric because they all break central symmetry, but this is the first time one has been successfully tested. While MoS2 did demonstrate the effect though, it does not always. As a bulk material, it does not, but even when working with atomically-thin sheets, it does not always. There must be an odd number of layers to generate any electricity, because with an even number the layers' output voltages will actually cancel each other out. Also electricity was only generated when the material was deformed in a specific direction.

Even with all of these conditions, this is still an important discovery, as it suggests other piezoelectric materials that can be just atoms thick. Being so thin, the materials will be naturally flexible, making it possible to use these generators to power wearable devices.

Source: Columbia University

New Speed Record for LEDs

Category: Science & Technology
Posted: October 16, 2014 05:26AM
Author: Guest_Jim_*

We may not think about it when we turn a light on, but every light source only produces so many photons in a second. Depending on the application, this emission speed can be critical, such as in telecommunications where 10 billion photons need to be produced in the blink of an eye. Typical LEDs only produce 10 million photons in that much time, but researchers at Duke University have found a way to close the gap.

The Purcell effect describes how emissions from fluorescent molecules can be increased when the molecules are near an intense light source. To create that light source, the researchers sandwiched the molecules between a 75 n silver nanocube and a thin film of gold. When the cube size and gap are tuned properly, the researchers realized a 1000 fold increase in fluorescence speed for the LED.

That record-setting speed may be surpassed before long though, as the researchers believe that aligning the molecules could magnify the effect. Regardless, fast light sources like this could prove invaluable for telecommunications and even quantum cryptography.

Source: Duke University

Two New Types of Qubits Created

Category: Science & Technology
Posted: October 15, 2014 03:41PM
Author: Guest_Jim_*

Teams around the world are working on technologies to enable quantum computers, and some teams are right next to each other. Two teams at the University of New South Wales have independently developed two quantum bit, or qubit systems, and have even set some records with them.

The fundamental units in quantum computers are qubits, which are particles put into a superposition. Superposition is a phenomenon that allows something to exist in multiple, exclusionary states at the same time, and from this quantum computers would be able to run algorithms far different than conventional computers. Superposition is fragile though, so qubits must be designed for great accuracy, and to achieve that here, both teams used pieces of pure silicon-28, which is nonmagnetic, unlike the mix of isotopes in modern electronics. One team put a phosphorus atom in their silicon, actually creating two qubits (the nucleus and the electron) while the other created an artificial atom that is very similar to MOSFETs, a kind of silicon transistor.

The ability to build a qubit in and from silicon is of great importance as it could allow current manufacturing methods and tools to construct quantum computers in the future. The phosphorus-atom qubit design also managed to survive for 35 seconds, which is impressive for any solid-state qubit, but is actually the record for silicon qubits.



Source: University of New South Wales

Researchers See Dopant Atoms Move

Category: Science & Technology
Posted: October 15, 2014 11:13AM
Author: Guest_Jim_*

If not for dopants, much of today's technology may not exist. Doping is the process of adding atoms to a material, to change its properties, and is critical for controlling the characteristics of semiconductors. After being placed in a material though, the doping atoms can move around, and ORNL researchers have finally caught them in the act.

Previous studies examining the diffusion of doping atoms had to use indirect macroscopic methods, and were limited to the surfaces of materials. By using a scanning transmission electron microscope though, the researchers were able to watch the as manganese and cerium atoms moved through the bulk of a piece of aluminum nitride. Just as theory predicted, though counter to normal expectations, the larger cerium atoms were observed to move while the smaller manganese atoms remained stationary.

By understanding how dopant atoms behave, this research could lead to better semiconductor devices, including LED lights. The color emitted by these lights is determined by the dopants, and their movement could affect when the LED fails.

Source: Oak Ridge National Laboratory

Understanding How Nanoparticles Can Enter the Skin

Category: Science & Technology
Posted: October 15, 2014 06:23AM
Author: Guest_Jim_*

Nanoparticles are a technology that could one day become completely ubiquitous with uses in everything from medicine to cosmetics. Before that can happen though, we must first learn how they behave, including how they can penetrate human skin. Researchers at the University of Southampton have recently conducted the research to determine just how that behavior works.

Other studies have examined why some nanoparticles will enter the skin and others will not, but never quite had the level of control necessary to make definitive statements. This new research does though, as it controlled the surface charge, shape, and functionality of gold nanoparticles for its tests. The results indicate that nanorods with a positive charge are two to six times better at penetrating the skin than other nanoparticles. Coating them with penetrating peptides increased the penetration by up to a factor of ten, allowing the particles to reach into the dermis.

This work could be used to develop nanoparticles for topical drug delivery, but it could also be used to prevent nanoparticles from entering the skin. If a cosmetic were to contain potentially toxic nanoparticles, they could be prevented from entering the skin just by designing them to be unable to.

Source: University of Southampton

Smart Batteries Could Give Warnings Before Short-Circuits

Category: Science & Technology
Posted: October 14, 2014 06:13AM
Author: Guest_Jim_*

The prospect of a battery exploding is not something anyone likes to think about, but the possibility does exist. With lithium-ion batteries seeing more and more use in consumer electronics, airplanes, and electric vehicles, the danger is only growing. Researchers at Stanford University decided to do something about this and have created a smart battery that can alert a user, before a fatal short circuit.

At one end of a lithium-ion battery is a carbon anode, and at the other a lithium metal-oxide cathode. Between them is a polymer separator that keeps the electrodes apart, while allowing lithium ions to flow through it. If a dendrite were to form from the anode though, it could pierce the separator and reach the cathode, causing a short. What the Stanford researchers have done to avoid this is add a layer of copper right next to the separator. The copper will act like a third electrode, measuring the voltage between the anode and the separator. If a dendrite does grow from the anode and touch the copper, the voltage difference will drop to zero, and thus provide a warning of impending failure.

By changing the distance from the anode, it would be possible to tune how much lead-time a warning comes with. By placing it closer to the anode, shorter dendrites will be detected, long before they can reach the cathode, cause a short, and potentially a fire.

Source: Stanford University

Dynamic Encryption Scheme Created

Category: Science & Technology
Posted: October 13, 2014 08:02AM
Author: Guest_Jim_*

Data security has always been important, but has never been quite as valued as it is now. To that end, new security systems are being developed, such as the dynamic encryption system created by a professor at the Technical University of Denmark.

Many telecommunication operators use the Advanced Encryption Standard (AES) to protect things like phone calls, and while it works, it is possible to decrypt it with enough computing power. This dynamic encryption system adds more layers to the encryption, making it more complex and difficult to crack, but what makes it especially effective is that it randomly chooses the layers to add. Every time someone makes a phone call using this system, AES and some additional layers are used to protect it, but with the next call, different layers are used. Even if someone were able to eavesdrop, they would find it harder to decrypt because they would not know the exact methods used to encrypt the transmission.

The dynamic encryption system is currently being marketed as a way to counter industrial espionage by the Dencrypt company the Denmark professor started.

Source: Technical University of Denmark

New Probe for Measuring Electric Fields Created

Category: Science & Technology
Posted: October 10, 2014 11:42AM
Author: Guest_Jim_*

Many devices and technologies rely on electric fields in one way or another, which makes it important to know the fields involved. To that end, researchers at NIST and the University of Michigan have developed a new electric field probe that uses some powerful quantum properties.

At the heart of the probe is a cylinder containing atoms that have been put into high-energy, Rydberg states using red and blue lasers. In these states, the rubidium or cesium atoms are extremely sensitive and reactive to electromagnetic fields, with electric fields altering the frequencies of light they absorb. This use of quantum mechanics actually makes the system self-calibrating, improving its precision. This allows it to measure field strengths as low as 0.8 millivolts per meter, which is 100 times weaker than conventional methods can measure. The range of frequencies it can measure reaches from 1 to 500 GHz, covering radio, microwave, millimeter-wave, and sub terahertz bands, but it may be possible to reach up to 1 THz.

For the time being the probe is tabletop sized, but by using photonic structures, it should be possible to shrink it down, possibly allowing it to be part of a NIST on a chip. Potential uses include testing and calibrating antennas, sensors, biomedical, and nanoelectronic systems, as well as enable the development of future devices.

Source: NIST

New Particle May help Explain a Fundamental Force

Category: Science & Technology
Posted: October 10, 2014 07:14AM
Author: Guest_Jim_*

One of the curious facts physics has given us is that there are only four fundamental forces in the Universe. The gravitational force, electromagnetic force, weak nuclear force, and strong nuclear force are all that exist, with everything we may experience being the results of these. Both gravity and the electromagnetic force are pretty well understood, while the nuclear forces are trickier to grasp. A new discovery by researchers at the University of Warwick however, may change that with regards to the strong force.

While gravity dominates on the large scale and electromagnetism covers how molecules interact with each other, as well as how electrons bind to nuclei, the strong nuclear force explains how quarks in protons and neutron stay together. It is so strong that it contributes more to the mass of a proton than the quarks that comprise it. The math behind the force are very complicated though and not well understood, in part because it is difficult to test predictions with experiments. That may change though thanks to the discovery of Ds3*(2860)-, which contains a charm quark and has a spin of 3. Charm quarks are heavier than the up and down quarks in protons and neutrons, making them easier to run calculations for. Having spin 3 is useful as a way to easily identify the particle.

The hope is that it will be possible to use Ds3*(2860)- as a benchmark for testing theories concerning the strong nuclear force. The particle was discovered from data from the LHC, and now there is hope that other new particles will be discovered that could help explain the weak nuclear force. Eventually such work may even provide answers for why there is more matter than antimatter.

Source: University of Warwick

New Fusion Reactor Design that could be Cheaper than Conventional Power Plants

Category: Science & Technology
Posted: October 9, 2014 12:39PM
Author: Guest_Jim_*

Sustainable nuclear fusion has been a target for researchers for decades, as it could potentially provide immense power from seawater and have produce little waste. Now there are many different groups working on different reactor designs and technologies across the planet, all with the goals stability and efficiency. Researchers at the University of Washington have designed a new reactor concept that could achieve both goals.

Critical to all fusion reactor designs is a mechanism that uses magnetic fields to control the superheated plasma fuel. While some designs call for superconductors to produce these fields, this design instead passes an electrical current through the plasma. The result is a dramatic reduction in size, required materials, and thereby cost. The researchers predict that a fusion power plant using this kind of reactor could provide a gigawatt of power and cost $2.7 billion. A similarly powerful coal plant costs approximately $2.8 billion, so the fusion plant would be in direct economic competition.

So far the prototype has demonstrated its ability to sustain the plasma efficiently. The final design, which will be ten times larger and more powerful, is still years into the future.

Source: University of Washington

Advanced Laser System for Remotely Mapping 3D Surfaces

Category: Science & Technology
Posted: October 9, 2014 05:52AM
Author: Guest_Jim_*

Lasers are a technology many television shows, movies, books, and games like to use in possible and impossible ways. Among the possible ways is using a laser system to scan a room or object, to create a 3D map of it, potentially for forensic use. Now researchers at NIST have developed a new mapping system that offers great accuracy, range, and speed

Laser detection and ranging (LADAR) is not a new technology as it bounces lasers off of objects, and analyzes the reflected light to determine distance. What is novel about the NIST system is its use of a frequency comb, which is able to precisely measure different frequencies of light. Here it is used to constantly calibrate the laser as it sweeps through a range of frequencies, increasing the system's accuracy and speed. It is actually able to resolve distances to within 10 micrometers, in half a millisecond, from as far away as 10.5 meters. In just 8.5 minutes, a 3D image of one million pixels can be generated.

The system is roughly the size of a desktop, but it should be possible to shrink it down to a chip-scale device. No doubt that will be useful for mapping crime scenes, but it could also find use with precision machining and assembly.

Source: NIST

Important Advance in Acoustic Imaging Made

Category: Science & Technology
Posted: October 8, 2014 03:05PM
Author: Guest_Jim_*

Chances are, most people are familiar with medical ultrasounds that use sound waves to peer into a patient, without doing any harm to the body. Ultrasounds are also used to image metal structures, in an effort to find cracks that could cause critical failures. The technology has been limited to just large problems for some time though, but researchers at the University of Bristol have finally developed a nonlinear technique that is much more sensitive.

Acoustic nonlinearity is an old idea, but no imaging method has been developed before now. It works by looking at the differences between acoustic fields generated from parallel elements in an ultrasonic array, as they are fired sequentially. The results are sound waves that are more sensitive to changes in the material, including microstructure changes, before they develop into macroscopic problems.

By catching cracks before they begin, it will be easier to predict the life of a structure, which could lead to thinner and lighter structures, including future aircraft. As the technique works with modern inspection equipment, it could be quickly adopted and put to use for its many applications.

Source: University of Bristol

Social Media Used to Manage Moods

Category: Science & Technology
Posted: October 8, 2014 07:01AM
Author: Guest_Jim_*

Some days, things just do not seem to go right and put you in a bad mood. When this happens, what do you do? According to researchers at the Ohio State University, many of us will look at social media profiles of those in worse situations than us.

The social networks many people use online are very special in that people are able to manage their use of them, whereas offline you do not always have a choice of who you encounter. Normally people look for positive news, but the researchers decided to investigate if this changes when the user is in a bad mood. To put their subjects in a bad mood, the researchers gave 168 college students a test on facial emotion recognition and randomly reported their performance as terrible or excellent. Now primed with a positive or negative mood, the participants were asked to review a new social networking site. On the site were eight profiles that had very similar, mundane postings, with the only real differences being with the profile rankings of career success and attractiveness. Those rankings were either very low or very high.

Everybody still focused on the profile of the more successful and attractive people, but those participants in a bad mood spent significantly more time looking at the other profiles. The researchers believe this shows that when we are in a bad mood, we will try to manage it by seeking out people in worse situations for a self-esteem boost, as we compare ourselves to them.

Source: Ohio State University

Using Online Games to Combat Scientific Fraud and Cherry-Picked Data

Category: Science & Technology
Posted: October 7, 2014 04:08PM
Author: Guest_Jim_*

Something many people are likely not aware of is the amount of fraud and cherry-picking in the sciences, including life sciences. This comes in part from a great pressure to publish, being overwhelmed by data, and from the people creating the hypothesis also being the ones to test it. To combat these issues, researchers at Carnegie Mellon University and Stanford University suggest using massive online labs that use video games to essentially crowd source the work.

Online labs have been used before as some of the researchers involved with this work recently reported the success of their own lab, EteRNA. Some 150,000 participants all registered to help develop and test hypotheses, and process the results of the experiments. With so many people involved, many sets of eyes are on every detail, so any mistake will likely be caught, and biases will be removed as those testing a hypothesis are not necessarily those who developed it. This also makes otherwise overwhelming amounts of data manageable as many thousands of people will look at the data, instead of the handful in a lab. It also keeps the entire process open and transparent.

The researchers making this suggestion do note two challenges that have to be overcome for this approach to work. One is the cost to create a massive online lab, which is still within the budge of the usual life science grant, but more importantly the view that video games do not align with serious or rigorous research.

Source: Carnegie Mellon University

New Web Privacy System Developed

Category: Science & Technology
Posted: October 7, 2014 12:12PM
Author: Guest_Jim_*

Privacy is a great concern for a great many people, and it is can also be tricky to achieve with how much technology today relies on sharing data. Such sharing opens up the possibility of data being illegitimately accessed without the consent or even the knowledge of the user. Researchers at the University College London, Stanford Engineering, Google, Chalmers, and Mozilla Research however, have recently created a new privacy system that might just be able to keep our data private, without breaking web applications.

The new system is call Confinement with Origin Web Labels (COWL) and works by confining data to only the party it was originally shared with. So, with COWL if a web app requests information from a website, it will receive that information, but will be prevented from sending it anywhere else. This way the site sharing the data maintains control, even after its transmission. This is in contrast to Same Origin Policy, which prevents programs from reading data from other websites and thus prevents mashup applications, or Cross-Origin Resource Sharing, which can easily be made to expose information.

Prototypes of COWL have already been tested for Chrome and Firefox and showed no perceptible impact on page-loading. For those interested in using COWL, it will be made freely available on the 15th of this month at http://cowl.ws/.

Source: University College London

US Navy Successfully Demonstrates Swarming of Unmanned Surface Vehicles

Category: Science & Technology
Posted: October 7, 2014 06:31AM
Author: Guest_Jim_*

In recent years we have seen an explosion of unmanned vehicles and vehicles capable of directing themselves, such as small drones and self-driving cars. Such vehicles are not limited to the land and air though, as the Office of Naval Research has been developing Unmanned Surface Vehicles (USVs) that could be used to protect manned ships. Now ONR researchers have successfully completed tests on a system giving these USVs swarm capability.

Swarming has long been a focus of robotics and artificial intelligence research, as it allows groups of individual actors to act as one, more powerful force. By bringing it to USVs, the vehicles are able to quickly respond to threats and work together, such as plotting out routes to interdict other vessels. The technology for automating the boats, called CARACaS (Control Architecture for Robotic Agent Command and Sensing), can fit into transportable kits and can be installed into most boats. It was also recently demonstrated in the James River in Virginia by as many as 13 boats acting to escort a Navy ship, and swarm a threatening ship.

The future of these boats and system is to deploy them to protect larger, manned ships, and to send them into dangerous situations, instead of Sailors or Marines. The boats would have offensive capabilities for deterring or destroying adversaries, but weapons fire could only be initiated by a supervising Sailor.



Source: Office of Naval Research

Crumpling Graphene to Create Electrodes

Category: Science & Technology
Posted: October 6, 2014 02:11PM
Author: Guest_Jim_*

Graphene seems to be a gift that just keeps on giving as researchers continue to find new ways to use it. Now those at MIT have found a very simple way to turn graphene paper into a stretchable electrode.

The wonder material is an atom-thick sheet of carbon that has many amazing properties due to this 2D structure, but in this case, multiple layers of graphene are combined to form a paper. This paper has been looked at before for use as electrodes in a supercapacitor, thanks to its high surface area to mass ratio, but not quite like this. The MIT researchers attached the paper to a polymer they had stretched out in two directions. They then released the polymer in one direction, and then the other. The first release caused the graphene paper to form parallel pleats, while the second crumpled it into chaotic folds. If the paper is stretched out again, the folds just smooth themselves out.

The researchers created a prototype supercapacitor with this material by placing an insulating hydrogel between two sheets, and as the hydrogel is also stretchable, the supercapacitor itself can survive being flexed and pulled. The crumpled graphene paper could also be used as electrodes in flexible batteries or in stretchable sensors.

Source: MIT

Majorana Fermion Finally Discovered

Category: Science & Technology
Posted: October 6, 2014 11:05AM
Author: Guest_Jim_*

When quantum mechanics was first being developed and scientists were first discovering the math that rules it, many interesting predictions were made. Some of these predictions have since proven true, but one has been particularly stubborn. The Majorana fermion is a particle that exists as its own antiparticle and finally, researchers at Princeton University and the University of Texas-Austin have proven its existence.

As the name suggests, antimatter is the opposite of normal matter, and when they collide, they will annihilate each other. The Majorana fermion is an exception to that rule, and was first described in 1937. This particle actually possesses properties of both normal and antimatter, making it neutral and keeping its interaction with its environment weak. In 2001 it was outlined how a Majorana fermion could be used as a qubit in quantum computers, which would benefit greatly from the weak interactions, and a new way to find it using a superconducting wire and a strong magnetic field.

The Princeton researchers constructed their superconducting wire out of iron atoms, aligned on a crystal of pure lead, and cooled it to just one degree above absolute zero. With a scanning-tunneling microscope, the researchers were able to image electrical signals at the tips of the wire, suggesting the presence of Majorana fermions, but only by imaging the rest of the wire, and showing the signals were only at the ends, the researchers were able to directly demonstrate they had created the elusive particle. Ironically the researchers also discovered that producing these particles is easier than they expected, provided the magnetism and superconductivity are present. Based on this, and their already simple setup, the researchers predict many more materials could be used to produce these particles, which could prove invaluable in the creation of quantum computers.

Source: Princeton University

Potentially Bringing Quantum Optics to Computer Chips

Category: Science & Technology
Posted: October 6, 2014 05:52AM
Author: Guest_Jim_*

While the possibility of quantum computers can grab headlines, there are more quantum technologies than that, and some can even be used today. Quantum encryption leverages quantum mechanics to transmit information securely using photons, but creating these photons is a little tricky. Doing so requires the generation of entangled photon pairs, which normally have the polarization of the original light source, but now researchers have developed a device to create cross-polarized pairs, as reported by The Optical Society's.

Normally cross-polarized photon pairs would be created using a classical mechanics process, which is a problem for quantum technologies, as quantum phenomena would be destroyed. Specifically, the entanglement between the photons would be undone. This new device gets around that by using a micro-ring resonator that exploits energy conservation. This suppresses the classical effects involved and actually amplifies the quantum processes.

Thanks to the small size of the device, under one square millimeter in area, we could see the generation of cross-polarized, entangled photon pairs be integrated into modern computer chips. The device can already be fabricated with processes compatible with those that make computer chips.

Source: The Optical Society

New Achievement in Interactive Code for Error Correction

Category: Science & Technology
Posted: October 3, 2014 05:19PM
Author: Guest_Jim_*

When using computers and mobile devices, most people probably do not realize just how much is involved with making sure the data they send and receive is accurate. Behind every transmission, especially wireless ones, error-correcting code (ECC) is employed to prevent errors, but current algorithms are not exactly ideal. Researchers at and from MIT will soon be presenting work on a new interactive coding scheme that could solve the problems.

Classical ECC has worked well for years and has the useful property that it works better as the size of a transmission increases. The algorithms are not well suited for shorter transmissions though, such as those used with distributed computing. For these transmissions a new system is needed and for twenty years researchers have been working on interactive code schemes that should do the trick. Like ECC, interactive code is evaluated on how much noise it can tolerate, the maximum transmission rate, and how long the encoding and decoding processes take. The MIT researchers' work is the first that is optimal in all three criteria.

Traditionally ECC works by adding extra bits to the transmission that describe the message, to reveal errors in the message, and then by going back and forth between the message and extra bits, the correct message can be discovered. This new system cuts that process short by building lists of what the message might be, and then exchanging them. As a device will always know what its message said, it is possible for the two devices to determine what the optimal decoding approach is. This way the scheme can tolerate a quarter of the data being altered and its processing time is linearly related to the length of the message. Now work still needs to be done to further optimize the scheme, but this is still a great step towards a new error correction system.

Source: MIT

Gold Nanoparticles Used to Improve Cardiac Patches

Category: Science & Technology
Posted: October 3, 2014 01:55PM
Author: Guest_Jim_*

Heart attacks are pretty serious and something very hard to recover from, in part because heart cells do not multiply and there are few cardiac muscle stem cells to repair the damage. Cardiac patches have been created to replace damaged cells, but because of how they are made, these patches can cause their own health problems. Researchers at Tel Aviv University have recently developed a new hybrid patch that could address those problems.

Traditionally the patches are made by growing cardiac tissue on a collagen scaffold from pig hearts. One of the problems with this approach is the potential for antigens that will trigger an immune response, causing the patient's body to attack the patch. To get around this the researchers instead harvest fatty tissue from the patient's stomach, as the body will not attack its own cells. This left an issue with connectivity, as the cells in the patch must respond to the electrical signals of the heart, and engineered patches do not immediately form the necessary connections. The solution the researchers tried was to deposit gold nanoparticles onto the cardiac tissue, providing the needed conductivity.

So far the nonimmunogenic hybrid patch has shown itself to transfer electrical signals faster and more efficiently than scaffolds without the gold nanoparticles, when tested in animals. The next step for the technology is to test it in larger animals, and eventually perform clinical trials.

Source: American Friends of Tel Aviv University

Watching Lithium Ions Enter Electrodes

Category: Science & Technology
Posted: October 3, 2014 05:57AM
Author: Guest_Jim_*

It is almost amusing how much we rely on lithium ion batteries, despite knowing quite little about their operation. Given the extreme nature of the inside of a battery though, perhaps that is not altogether surprising. Still some researchers do find ways to looking inside, such as those at Michigan Technological University who have uncovered what happens when ions enter the anode.

As part of how batteries operate, lithium ions will move from one side to the other, entering and exiting the electrodes as is appropriate. That movement is not exactly simple or easy though, which is something the Michigan researchers want to change. With transmission electron microscopy, the researchers were able to observe atomic shuffling, as they call it, when lithium enters an anode. The structure of the electrode has to change to receive the lithium ion, expanding and contracting to form a sandwich structure.

Obviously this explains how the ions move through the electrodes, but it also explains why anodes made of a layered material fail. The stress and phase transitions involved are too great for the material to survive over repeated charge/discharge cycles.

Source: Michigan Technological University

Magnetic Majority Logic Gate Created

Category: Science & Technology
Posted: October 2, 2014 02:31PM
Author: Guest_Jim_*

For years silicon chips and transistors have been used to build computers, but this may change in the future as modern technologies reach their limits. Exactly what the future may bring is hard to predict though, as there are many contenders and some are quite different from what we have today. Now one of these contenders has gotten quite a boost from researchers at the Technische Universität München and the University of Notre Dame, as they have successfully created a majority logic gate from a 3D stack of nanomagnets.

Single magnets have their own magnetic field, but when multiple are brought together, their individual fields will couple into one. The majority logic gate works by holding three nanomagnets in a fixed position, with a fourth free to move nearby. That free nanomagnet will flip its orientation depending on the orientation of the majority of the fixed nanomagnets, hence the name. Potentially a majority logic gate could be used as a programmable switch in a digital circuit, especially if combined with domain wall gates, which the researchers have been working on for years, as they enable the routing, buffering, and synchronization of signals in magnetic circuits.

There are many promising aspects to this technology, including low energy consumption, resistance to radiation, and being non-volatile. It also lends itself well to vertical stacking to improve scalability and packing density, and by using coupled fields transistors the contacts and wiring of transistors are not required.

Source: Technische Universität München

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