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Science & Technology News (1280)

Air-Breathing Electric Thruster Created for Low-Orbit Satellites

Category: Science & Technology
Posted: March 6, 2018 10:52AM
Author: Guest_Jim_*

What goes up must come down, is an old but accurate saying that poses a problem for satellite missions, especially those in low orbit. While the atmosphere 200 Km up is thin, it is still present enough to produce drag on a satellite, decaying its orbit. To compensate for this a thruster can be used, but once its propellant supply runs out, the satellite will fall from orbit, just like what happened to the GOCE gravity-mapping mission. For GOCE the propellant was xenon, but thanks to new work by the European Space Agency, future low-orbit missions, both for around Earth and potentially other worlds, air-breathing thrusters may be used instead.

This new thruster had to overcome the challenge of air molecules bouncing away at the intake, instead of being collected and compressed, but this was achieved. Once collected the molecules can be given an electric charge and propelled from the back producing thrust. The only parts that need any power are the coils and electrodes, with the remainder working on a passive basis, making the thruster simpler and efficient.

To test the innovative intake, normally one would feed it and measure the density at the collector, but instead the researchers decided to have the electric thruster attached and measure the thrust produced. Initially a stream of xenon was used, to confirm it was working, but then a feed of nitrogen-oxygen air replaced it, and the switch could be visibly observed by watching the engine plume change color. The system was then ignited successfully and repeatedly, confirming the feasibility of this design.

By using an air-breathing design, this removes the need for a special propellant on a satellite mission, making it possible for the satellite to continue its mission for a longer period of time. Also, as it can work with other kinds of gases, it could be used to enable satellite missions in low-orbit around a planet like Mars, with the carbon dioxide in its atmosphere serving as the propellant.

Source: ESA

Atmospheres and Densities Analyzed for Four TRAPPIST-1 Planets

Category: Science & Technology
Posted: February 6, 2018 01:43PM
Author: Guest_Jim_*

Last year NASA announced the star TRAPPIST-1 had seven Earth-sized planets orbiting it with multiple inside its habitable zone. Naturally these planets have been more closely looked at since, to determine if any of the planets might be able to support life. Using several space and ground-based telescopes, including the Hubble and Spitzer Space Telescopes, we now know that three of these exoplanets do not have high concentrations of hydrogen in their atmosphere. This is important as it suggests their atmospheres could be similar to Earth's, as opposed to the atmospheres on gaseous planets like Neptune.

The four planets investigated were TRAPPIST-1d, e, f, and g, which are the four that exist within the star's habitable zone, though one is at the inner-edge of this zone. The habitable zone of a star is the area in which a planet could have liquid water on its surface, which is necessary for life as we know it. Being a dwarf star, TRAPPIST-1 is much smaller and colder than the Sun, so much so all of its planets, not just those in the habitable zone, are closer to it than Mercury.

To analyze the planets' atmospheres, the telescopes looked at them as they transited TRAPPIST-1, so the star's light would pass through the atmospheric gases. This would leave a fingerprint of the gases on the observed spectra of the light and from that we could determine some of the atmospheres' characteristics. In addition to studying their atmosphere, the densities of the planets were also better measured, indicating the planets are mostly made of rock and some may have up to five percent of their mass in water. That would be 250 times more water than the oceans on Earth.

More observations and analyses are going to be necessary to further understand these planets 40 light years away, and likely those discoveries will come from the James Webb Space Telescope that should be launching next year. This next telescope has been designed and developed to far exceed the capabilities of the Hubble Space Telescope, but it has only been because of Hubble and other telescopes that we know what technologies and approaches get the most information.

The embedded media are from the ESA Hubble website with one being a comparison of star habitable zones.


Source: Hubble [NASA], [ESA] and Spitzer

Volumetric Display Made The Builds 3D Images In Air

Category: Science & Technology
Posted: February 1, 2018 09:21AM
Author: Guest_Jim_*

Science fiction has promised us many things for the future and thankfully we have scientists around the world working to fulfill those promises. Researchers at Brigham Young University are among them as they worked on their 'Princess Leia project' and they have now succeeded in creating a system to project 3D images in open air. These are not holograms though, as those involve scattering light on a 2D surface, but volumetric images as they exist in three dimensions, allowing you to view it from all sides. Other teams of researchers have also been working on producing volumetric imagery, but this is the first to combine the optical trapping and colorful lasers.

The way this display works is to take a particle of cellulose and trap it with a laser. This trapping allows the laser to precisely move it around while another set of lasers illuminate and color it. Thanks to how quickly the particle is being moved around, persistence of vision makes it appear lines are being painted in mid-air, forming a volumetric image. The researchers liken it to a 3D printer for light, with the cellulose particle effectively printing light as it is move around.

Thus far the researchers have displayed volumetric images of a butterfly, a prism, the university's logo, rings wrapped around an arm, and a recreation of Princess Leia by an individual in a lab coat crouching much as Leia does at the beginning of the famous message.



Source: Brigham Young University

Broadband Achieved Over Wet String

Category: Science & Technology
Posted: December 13, 2017 12:49PM
Author: Guest_Jim_*

Physics is an amazing thing, especially when you turn it to something kind of silly. An employee at a British IP did just this by demonstrating a broadband, ADSL signal can be carried by wet string. To be more specific, it was two meters of string soaked in salt water because fresh water would not do the trick. After connecting the string, its speed was measured at 3.5 Mbps for download, proving it works.

Why does this work? Because the physics involved with the signal does not solely rely on an electric current, which the string would resist. Instead the cable acts as a waveguide for electromagnetic waves of such high frequency, the material does not matter much.

It is safe to say string is not going to become a part of broadband connections, but this still demonstrates an interesting and amusing quirk to the technologies so many of us use every day.

Source: RevK's Rants Blog

All of the Top 500 Supercomputers Now Run Linux

Category: Science & Technology
Posted: November 16, 2017 10:18AM
Author: Guest_Jim_*

While it might not be a common operating system among consumers, Linux now dominates among supercomputers. All of those on the TOP500 list of the world's fastest supercomputers use the open-source operating system, and it is that open-source nature that has helped it achieve this milestone. Many supercomputers today are built for specific tasks, and to get the most out of them, customized operating systems are desired. Instead of developing a new OS from scratch, the open-source code of Linux allows the optimizations to be developed and put in place at much lower cost.

Source: ZDNet

Iridium Can Be Used to Destroy Cancer Cells

Category: Science & Technology
Posted: November 3, 2017 01:08PM
Author: Guest_Jim_*

Iridium is a rather rare metal, and while it is associated with the asteroid that led to the mass extinction of the dinosaurs and much more life, it may come to be a powerful tool for preserving life. Researchers at the University of Warwick have discovered a means to use iridium to destroy cancer cells, and this method does not damage normal healthy cells.

To destroy the cancer cells, the researchers made a compound of iridium and an organic material, and then light just needs to shine on it. The compound can be targeted specifically at cancerous cells, and it will transfer the energy of the light to the oxygen within the cell, producing singlet oxygen. Singlet oxygen is a high-energy form of oxygen that is highly reactive and poisonous to the cancer cell. Healthy cells are not affected by this process though, and the researchers even tested the method in healthy cells to prove as much. The light used in the process is just visible light and for their testing the researchers used red laser light, as it can reach through the skin.

While this research is on its own impressive, it also shows the value in exploring even more precious metals for their use in cancer chemotherapies. Platinum, another precious metal, is already used in over half of such treatments, and others could prove equally potent.

Source: University of Warwick

Improved Memory Management Developed for On-chip DRAM

Category: Science & Technology
Posted: October 23, 2017 11:06AM
Author: Guest_Jim_*

As processors have become faster and faster, the time it takes to go off-chip to access data has become more and an issue. This is where on-chip high-bandwidth caches come in, and even why some have been adding DRAM to a chip's packaging. The problem is DRAM is significantly different from the SRAM typically used for on-chip caches, which is why MIT researchers have developed a new cache management system.

The critical difference between SRAM and DRAM concerns how the two memory technologies store data and the impact this has on locating specific data. All data is tagged with a piece of metadata identifying where it is also located in the system's main memory and these tags are run through a hash function. The purpose of this hashing is to produce very different values for actually similar pieces of information, as this will prevent bottlenecking at specific locations. The outputs of the hash function is stored in a hash table, and sometimes multiple data items are referenced by one entry, if they all share the same hash output, but checking these few items is still more efficient than going through the entire tag list. This is where the difference between SRAM and DRAM comes out though, as SRAM uses six transistors for each bit of data while DRAM uses only one. This does give DRAM an advantage in space efficiency, but SRAM has some processing capability, allowing it to search the hash table for the desired information, while the processor needs to do this for DRAM-stored data, which takes time and bandwidth.

The solution from MIT, which has been dubbed Banshee, adds three bits to each entry in the hash table, with one identifying if it can be found in the DRAM cache, and the other two giving a location relative to the other data items sharing the same hash index. As the entry in the table is already around 100 bits, this is not much overhead especially as it can increase the data rate of on-chip DRAM by 33 to 50%. Banshee also adds a tag buffer to address issues of one processor core not knowing when another has data put in the DRAM cache. The buffer is only 5 KB, so it does not take up much, and when it is full all of the cores have their virtual-memory tables updated, allowing the buffer to clear and start fresh.

Source: MIT

Wireless Data and Power Combined

Category: Science & Technology
Posted: September 18, 2017 11:02AM
Author: Guest_Jim_*

In recent years there has been a trend for technologies to go wireless for both form and convenience. Wireless charging is among the advancements being added to technologies, but it often comes at increased cost and weight because it requires special components be added to the device. While there is a reason these parts need to be added, instead of using those already present, researchers at North Carolina State University decided to see if it was possible to work around this reason, and succeeded.

Wireless systems, for data or power, require the use of antennas and radios and typically these parts will be tuned design for their intended purpose for greatest efficiency. For wireless power the parts are tuned to a narrow bandwidth, which minimizes power loss but makes them unsuited for data transfer. What dawned on the researchers is that while the wireless power system does require narrow band antennas, the whole system bandwidth does not need to be so small. By combining narrow-bandwidth components with a wide-bandwidth system, the researchers were able to achieve both power and data transfer.

When the researchers tested this new design, they were able to transfer 3 W of power while transmitting 3.39 MB/s with only a 2.3% loss in efficiency due to the data transmission. If only 2 W of power was transferred though, the efficiency only dropped by 1.3%. These tests were not done with the device resting directly on the charging pad with, but a little more than six inches away, demonstrating that this system can work over a distance.

Source: North Carolina State University

AI Recreates Game Engine by Watching Gameplay Videos

Category: Science & Technology
Posted: September 12, 2017 10:33AM
Author: Guest_Jim_*

Games and artificial intelligence are not exactly strangers as there have been various kinds of AIs in games for years. In the future though, we might see AI playing a role in creating the games and not just giving us opponents. This is thanks to researchers at Georgia Institute of Technology where they have made an AI that can recreate a game's engine after watching video of it.

As the AI watches video of a game, it studies the frames to construct a model of how the game works and how players will interact with it. The researchers started it on Super Mario Bros. with a speedrunner video, which would be a more difficult test for it as the player is focused just on the goal. One video was not enough to develop a model that will clone the original engine, but by providing the AI additional videos, it was able to create something accurate enough another AI could not distinguish between it and the original game.

Since working with Super Mario Bros., the researchers have moved on to experimenting with Mega Man and Sonic the Hedgehog. Ultimately we could see this turned into a tool to accelerate game development and to experiment with different kinds of gameplay.

Source: Georgia Institute of Technology

Unknown Semiconductor Behavior Discovered with Potential Efficiency Impact

Category: Science & Technology
Posted: September 6, 2017 11:32AM
Author: Guest_Jim_*

When thinking about the semiconductors within our computers and other devices, as we surely do at times, chances are we just think about silicon, but there are more materials than that one involved. On its own, silicon actually will not conduct electricity, which is why other molecules called dopants are added to the material, but adding too many doping molecules will eventually block the electrical currents. The cause of this increased resistance is believed to be from the electrons bouncing off of the dopants, but now researchers at the University of Illinois at Chicago have discovered another mechanism that increases resistance.

To make this discovery the researchers started with chips of cadmium sulfide for their semiconductor base and then used copper ions as the dopant. Instead of connecting the chips up run a current through them, the researchers instead shot a powerful blue laser at them, with the energy of the laser being enough to generate an electrical current. Very high energy X-ray images were taken at the same time just millionths of a microsecond apart to reveal what was going on. To the researchers' surprise, the copper ions were intermittently forming bonds with the semiconductor base, and these bonds were then impairing conduction.

This behavior has not been seen before and it would be impairing the speed and efficiency of the semiconductor computers it affects. Fortunately, now that we are aware of this dynamic it will be possible to create designs that minimize it.

Source: University of Illinois at Chicago

Researchers Found Action Games Can Impact Brain Matter

Category: Science & Technology
Posted: August 14, 2017 10:27AM
Author: Guest_Jim_*

For many years people have been studying what impacts video games can have on humans and producing various results. New researchers at McGill University have found that action games can actually lead to a loss of grey matter in the hippocampus, though what long-term consequences this may entail require further study. However, playing 3D-platform games, like Super Mario 64, can actually increase the amount of grey matter.

For this study the researchers had 64 participants ranging in age from 18 to 30 and had them play 90 hours of different kinds of games. These games included first person shooters like Call of Duty, Killzone, Medal of Honor, and Borderlands 2, along with the previously mentioned Super Mario 64, and the participants had not played these games previously. The researchers found that for some of those playing the FPS games, the hippocampus lost grey matter after 90 hours, while no one lost any while playing the 3D platformer, or even saw an increase. There is more to it than this though as the researchers found the loss of grey matter also depended on the kind of learner people are. Response learners, who will follow their brain's autopilot and reward system for navigation, experienced the loss while spatial learners who use the hippocampus to navigate saw an increase in grey matter. It is not just a matter of the kind of game you are playing but also how you learn. The increase seen from Super Mario 64 occurred for both types of gamers.

Exactly what about this genre causes this atrophy is still unknown and will require further study, as will determining the long-term consequences of this loss. People with lower amounts of grey matter in the hippocampus though are known to be at an increased risk of neuropsychiatric illnesses, such as depression, schizophrenia, PTSD, and Alzheimer's disease.

Source: McGill University

Nearly Perfect Single-Crystal Graphene Grown on a Large Scale

Category: Science & Technology
Posted: August 10, 2017 03:22PM
Author: Guest_Jim_*

Since its discovery, many people have been working very hard to bring graphene to various products, thanks to its strength, flexibility, and very high conductivity. One of the primary issues with the material has been the difficultly of synthesizing it, especially on large scales. Researchers at the Institute for Basic Science in Korea have discovered a possible solution though, growing large pieces of single-crystal graphene quickly and possibly without an upper-size limit.

Graphene is an atom-thick sheet of carbon with a hexagonal molecular structure to it that can transport electrons at a very high speed, while still being very strong, very flexible, and transparent. These properties give it the potential to very successfully replace silicon in electronics, but achieving this would require large, high quality pieces of the carbon allotrope. Polycrystalline graphene, which consists of many crystals that interface with each other at various angles, can be produced at large sizes, but those varied interfaces are defects that impair the material's performance, so single-crystal graphene is needed. Previously producing just a few square centimeters would require a couple hours, but this new method was able to produce a 250 cm2 (5x50 cm 2) piece of nearly perfect graphene in just 20 minutes. The researchers accomplished this by starting with a copper-foil substrate that was heated to around 1030 ºC, allowing its atoms to align, forming a single crystal of copper. Then carbon atoms were deposited onto it via chemical vapor deposition, and these atoms formed islands that eventually coalesced to make a nearly perfect, single-crystal of graphene.

Obviously this is terrific news for the future of graphene, especially as it may be possible to scale it up just by using larger pieces of copper, while still being fast and cheap. It could also lead to new ways of producing other 2D materials with special and desirable properties.

Source: Institute for Basic Science

System Developed for Optimizing Use of Caches

Category: Science & Technology
Posted: July 10, 2017 02:25PM
Author: Guest_Jim_*

A fundamental part of every processor is its caches, where the cores can keep what information they need for performing the operations assigned to them. As these caches are on on-chip, accessing them is very fast, but that does not mean there are not better ways to allocate the cache space among the cores. Researchers at MIT have developed a system called Jenga that finds the optimal distribution of not only the local cache but also DRAM for a CPU.

Two advantages to having caches built into a chip are that accessing the data in the caches is very fast and it takes little energy to do so, compared to off-chip memory. This makes optimizing the use of a chip's cache rather valuable, but modern chips need to be designed as a compromise between the capacity and latency needs of various programs. What Jenga does is measure the latency between each processor core and each cache it can access and uses that information to build a cache hierarchy. The hierarchy considers the differences between different levels of cache, like the on-chip L1, L2, and L3 caches but Jenga actually also makes measurements for using DRAM. Once the optimal cache level is determined, algorithms from an older system called Jigsaw are used to optimally allocate the caches for the entire chip. Jenga builds on Jigsaw by considering cache level in its algorithms, but the Jigsaw algorithms for optimizing along the latency-capacity curve are still valid once level is determined.

The researchers tested Jenga by simulating a system with 36 cores and found it could increase processing speed by 20-30% while reducing energy consumption by 30-85%. A fairly significant improvement for something that just improves how the hardware is used, and as more and more cores are added to CPUs, this could become an even more valuable system.

Source: MIT

3D RRAM Chip Combines Data Storage and Computing

Category: Science & Technology
Posted: July 6, 2017 11:10AM
Author: Guest_Jim_*

The rate of innovation is always increasing as new creations lead to more new projects, but this progress is not uniform. In some instances the ability to produce something can come to outpace the ability to use it, and this is happening with data currently. Right now we have the ability to generate more data than many systems can efficiently handle, but there are many researchers working to change that, including some at MIT and Stanford University where a very advanced chip has been created that combines data storage and processing.

This new chip combines two technologies that can still be considered futuristic for computers; carbon nanotubes and a 3D architecture. Modern computer chips have a 2D design, though some have a 2.5D design with layers stacked and connected to each other. The benefit to a full 3D design is that the multiple parts of the chip are able to communicate with each other much more quickly and efficiently than what is currently possible. Carbon nanotubes can also take this to a new level as their small size and electrical properties allow the chips to be made denser. In this case the chip is a form of resistive random-access memory (RRAM), which is a kind of nonvolatile memory and has some one million RRAM cells and two million carbon nanotube field-effect transistors. This combination of memory and computing removes the bandwidth bottleneck between data and processing that is an issue with today's largest datasets.

To prove the capabilities of this design, the researchers also added over one million nanotube-based sensors for detecting and classifying gases. The measurements from the sensors were processed all in parallel and written directly to memory, thanks to this integrated design of emerging nanotechnologies. What makes this accomplishment even more impressive is that the chip is compatible with CMOS, so such an RRAM chip could be combined with current silicon chips and there is a fair chance there will be many more applications for this design in the future.

Source: MIT

Study Suggests Network Traffic Can Help Stop Malware Attack

Category: Science & Technology
Posted: May 22, 2017 11:20AM
Author: Guest_Jim_*

Before large malware attacks, systems need to be infected by the malware, where it can linger undetected for weeks or months. Until a sample of the malware is discovered, traditional anti-virus software cannot remove it, but researchers at Georgia Institute of Technology, with collaboration from EURECOM and the IMDEA Software Institute, have found a way to help catch malware before it is activated. The key is monitoring network traffic.

For many pieces of malware, it needs to communicate with command and control computers, and this communication naturally involves network traffic. The researchers looked at over five billion network events from five years of ISP data and the DNS requests made by 27 million malware samples, and then compared them to the re-registration of expired domains. Such domains are often used as the launch sites for malware attacks and certain networks are more prone to abuse than others. Interestingly though, there were often months of lag time between a domain name being re-registered and attacks starting. To help with this work, the researchers created a filtering system to distinguish between benign and malicious traffic, which also involved the largest malware classification to date, differentiating malware from potentially unwanted programs.

In the end the researchers found there were signals of malware infection weeks to months before the malware was found. For this defense strategy to work though, network administrators will need to learn what normal behavior is for their networks so that bad activity can be identified, but it still indicates how the next generation of defense mechanisms can be designed.

Source: Georgia Institute of Technology

Lithium Batteries Improved by Graphene-Nanotube Hybrid

Category: Science & Technology
Posted: May 19, 2017 12:01PM
Author: Guest_Jim_*

It is beyond any doubt that lithium-ion batteries have significantly impacted the world with their high energy density and ability to be recharged. Unfortunately they are also fairly near their current limits, without the development of new technology. Many researchers and institutions are working such technologies and those at Rice University have recently created a battery with three times the capacity of what we see today.

What makes this new battery special is that its anode is not made of graphite, but a hybrid of graphene and carbon nanotubes. This hybrid is actually a metal and can hold more lithium ions than modern batteries, but most importantly it overcomes an issue common with other lithium-metal batteries. Dendrites are lithium structures that can grow inside of a battery, crossing the electrolyte possible connecting the two electrodes, causing a short circuit. Such a short circuit could cause the battery to fail, catch on fire, or explode. The hybrid materials has a high surface area and a low density, which is a valuable combination as it means the lithium particles are free to move in and out as the battery charges and discharges. This also allows the lithium to evenly distribute itself, which suppresses dendrite growth.

The prototype batteries the researchers have built have their capacity limited by the cathode, but this anode material is still able to hold near the theoretical limit of 10 times more energy than traditional lithium-ion batteries. When tested, the full batteries also were able to retain 80% of their capacity after some 500 charge-discharge cycles and were free of dendrites when examined with an electron microscope.

Source: Rice University

Transparent Semiconductor Thin Film with Record Conductivity Discovered

Category: Science & Technology
Posted: May 8, 2017 11:38AM
Author: Guest_Jim_*

You might not realize it, but a lot of the devices you rely on everyday probably include some amount of the material indium. This is because indium tin oxide (ITO) is a transparent conductor, making it ideal for use in flat-panel displays and solar cells, but indium is also rather rare, which is why so many have been looking for a viable replacement. Researchers at the University of Minnesota have recently discovered a transparent semiconductor that has the highest-ever conductivity of a thin film oxide semiconductor.

This new material is barium stannate (BaSnO3), a combination of barium, tin, and oxygen. It is a semiconductor with a wide band gap, which is important as this allows it to be transparent. The bandgap is the amount of energy it takes for an electron to enter the conduction band of a material, where it can move about freely. Typically semiconductors with wide bandgaps have low conductivity, but this is an exception, meaning the conducting film could be used in various electronic devices in the future. With barium and tin both being much cheaper than indium, there will certainly be a great interest in it.

The next step is to reduce the defects that form in the material, further improving its conductivity.

Source: University of Minnesota

Water Interlayer Found to Improve New Energy Storage Device

Category: Science & Technology
Posted: May 1, 2017 09:56AM
Author: Guest_Jim_*

When it comes to storing electrical energy the two dominant choices are batteries and capacitors. Batteries can store a great deal of energy but capacitors can charge and discharge significantly faster, so there has been a lot of effort to create a device that combines their properties. Researchers at North Carolina State University have created a proof-of-concept material that may help lead to exactly that.

For their work, the researchers were using crystalline tungsten oxide and a layered, crystalline tungsten oxide hydrate, which is almost identical except for atomically thin layers of water between the tungsten oxide layers. When the researchers charged the two materials for ten minutes, they found the regular tungsten oxide stored more energy than the hydrate, but after charging for just 12 seconds, the hydrate stored more. The hydrate also was more efficient at storing this energy, losing less to heat.

Currently this is just a proof-of-concept for the idea of adding layers of solvents, like water, to materials to tune the ability for a material to transport ions between layers. Potentially this could be used to create thinner batteries, increased acceleration for electric vehicles, and faster storage for power grids using renewable energy sources. The researchers are now moving forward with National Science Foundation-funded work to tune the interlayer and hopefully improve their understanding of these materials.

Source: North Carolina State University

3D Stacked Memory Developed to Aid Graphics Processing

Category: Science & Technology
Posted: April 27, 2017 12:05PM
Author: Guest_Jim_*

Researchers at the Pacific Northwest National Laboratory and University of Houston have developed a means to increase 3D rendering speeds by up to 65%. It involves leveraging the logic layer that exists within 3D stacked memory to do some processing within the memory, instead of putting it on the GPU.

The PNNL researchers normally work with supercomputers, but when one of them asked if 3D stacked memory could be used to help render 3D graphics, the attention shifted towards video games. Science will still benefit from this work though, as 3D rendering is used with visualizations, models, and virtual reality. During their testing on Doom 3 and Half-life 2, the researchers found the best step to have the memory process is one of the last steps, anisotropic filtering as it often creates a lot of traffic on the graphics card. By removing this traffic and performing the filtering as the first step, they found the greatest performance boost.

Source: Pacific Northwest National Laboratory

Coating Developed for Improving Lithium Ion Batteries

Category: Science & Technology
Posted: April 18, 2017 12:44PM
Author: Guest_Jim_*

The invention of lithium-ion batteries has made many other technologies possible, thanks to the high energy density they give us. However, we are always looking for more and the current battery design has limits, as do possible alternatives. Researchers at the University of California, Riverside have found a possible way to break one of those alternative's limits with an inexpensive coating.

Inside of every battery is a cathode and anode, the electrodes for the positive and negative charged sides respectively. Graphite and other carbon materials are currently used in lithium-ion batteries for the anode, because it works well and is rather resilient. A lithium metal anode would be far superior though, providing up two ten times the energy density, but lacks that resiliency as dendrites form from the anode, cutting its lifespan short. What the researchers discovered is that by adding methyl viologen to the electrolyte, the ion-containing fluid between the electrodes, a coating would form over the lithium metal as the organic molecules touch the metal, preventing dendrite growth.

The researchers have already found that the methyl viologen can triple the cycling lifetime of the battery, which is truly significant and could be increased with further investigation. It is also worth noting that methyl viologen is very low in cost and is already compatible with manufacturing lithium ion batteries.

Source: University of California, Riverside

Material Made That Draws Moisture From Dry Air

Category: Science & Technology
Posted: April 14, 2017 11:07AM
Author: Guest_Jim_*

Water is a compound necessary for human life but is not always accessible. To help with that, researchers at MIT have created a device using a metal-organic framework originally invented at Berkeley Lab that can collect moisture from even dry air and use sunlight to then release it.

A metal-organic framework (MOF) is exactly what it sounds like as it combines metal with organic molecules to create porous, rigid structures. These structures can be used to hold gases and liquids. In this case zirconium metal is used with adipic acid and the result is a MOF that loves water and can pull it out of air as dry as a desert, just 20-30% humidity. The solar-powered harvester that was built uses just one kilogram of the MOF, but is able to generate 2.8 liters of water from that arid air after just 12 hours.

Obviously this invention is very significant as it can bring water to so many people who need it, but we may see something even better coming in the future. This particular MOF is only able to absorb 20% of its weight in water, but there are others that may be able to reach 40%, and it should also be possible to tune the material for specific humidities.



Source: Berkeley Lab

Thin and Smooth Layer of Silver Could Advance Displays and Computers

Category: Science & Technology
Posted: March 24, 2017 12:51PM
Author: Guest_Jim_*

For a long time the material indium tin oxide (ITO) has been a requirement in several technologies because it is a transparent conductor. One issue with ITO is that indium is quite rare, making the material ever more expensive, and another is that it is rather fragile. A potential alternative for a transparent conductor is a silver ultrathin film, which has issues of its own but researchers at the University of Michigan have recently solved some of these.

When trying to create a thin film of silver, it typically cannot be smaller than 15 nm because silver likes to cluster into islands and not form an even coating. What the Michigan researchers discovered is that adding just 6% aluminum the silver can be coaxed to form a film just 7 nm thick. After applying an anti-reflective coating they were able to make one layer up to 92.4% transparent. The aluminum is even more useful than that though, as the ultrathin film did not tarnish in open air after months, unlike pure silver films that tarnish almost immediately, disrupting its conductive properties and transparency.

While there are some obvious uses in displays, this silver ultrathin film has far more potential than that. In this form, silver is able to carry plasmon polaritons, which are oscillations created when light strikes a metal and they carry the information of the light wave. Plasmons can be much smaller than the wavelength of the light though, allowing the silver film to act as a kind of superlens. This gives the film potential uses inside of computer chips as a means to transmit information optically, allowing for faster data transfer than electronic transmission currently allows. On top of that, by alternating layers of the silver film with an insulator, like glass, a metamaterial hyperlens could be made, which could then image objects smaller than the wavelength of light and enable laser patterning, such as that used to etch computer chips, to reach smaller feature sizes.

Source: University of Michigan

Battery Designed for Powering and Cooling Computer Chips

Category: Science & Technology
Posted: March 15, 2017 12:09PM
Author: Guest_Jim_*

There are a number of battery technologies out there that employ different methods to store and deliver electricity. Many store energy within their solid electrodes, but flow batteries actually use liquid electrolytes for storage. Today you can find large scale flow batteries used in stationary applications, but thanks to researchers at ETH Zurich and IBM Research Zurich we may see them coming to computing devices thanks to a clever use of the liquid electrolytes.

As the name indicates, the two liquid electrolytes in a flow battery move through it, and with the proper membrane is between them, an electrical current is produced like in any battery. What occurred to the researchers is that the electrolytes could also be used to transport heat away from a system, like a liquid cooling system for a computer. Instead of designing something comparable in size to an AIO cooler, the researchers went even smaller, making a battery just 1.5 mm thick so that it can be integrated into a chip stack. In a chip stack individual chips are stacked on top of each other to save space and energy, but by putting a thin battery micro-cell in between it is possible to power and cool the chips.

This micro-battery design offers a record-setting 1.4 W/cm2 (1 W/cm2 after subtracting the power to pump the electrolytes) and is able to dissipate more heat than what the battery generates as electrical energy. However further optimize is going to be needed because, record setting or not, it is not enough power for the computer chip to operate. Still, this is a promising proof-of-concept that may have potential in a variety of applications and could improve large-scale flow batteries as well.

Source: ETH Zurich

Ultrafast Laser Pulses Could Lead To Lightwave Computers

Category: Science & Technology
Posted: March 13, 2017 01:09PM
Author: Guest_Jim_*

Everybody wants their computer to run faster, but we are approaching theoretical limits on just what traditional silicon-based electronics are capable of. For faster speeds, new technologies will need to be developed, and they may take advantage of some unusual physics. Researchers at the University of Michigan have made a discovery that could lead to these faster computers by way of lightwave electronics.

In lightwave electronics, electrons are manipulated by an oscillating electric field generated by ultrafast laser pulses, causing them to move at high speeds in certain directions. In modern electronics, when one fast moving electron hits another heat is produced, but with lightwave electronics the electrons are moving so quickly they are not likely to strike another before they stop. What the Michigan researchers have done is demonstrated this ability to move electrons in a semiconductor using pulses less than 100 femtoseconds long of terahertz radiation. These pulses pumped enough energy into the electrons to pop them up to a higher energy level, allowing them to move around the semiconductor crystal. The paths the electron take is not random though, or even determined by the laser pulses but by the structure of the crystal. When the electrons fall back down to a lower energy level, they emit light as an even shorter pulse than the terahertz source and these pulses could actually be used to read and write information to other electrons.

Eventually we could see lightwave computers operating ten to 100,000 times faster than modern computers, but there is still a lot to do before then. Before then we may see this used to optimize chemical reactions and in quantum systems, including quantum cryptography.

Source: University of Michigan

IBM Announces Plans to Build Universal Quantum Computing Systems

Category: Science & Technology
Posted: March 6, 2017 02:04PM
Author: Guest_Jim_*

Quantum mechanics is a weird and wonderful science that can allow seemingly impossible things to happen, such as particles to exist in multiple places at the same time. This and other phenomena have potential for use in quantum computers, but building such systems is far from easy, naturally limiting researchers' access to the potential computing power. Today IBM announced IBM Q, an initiative to build commercially available universal quantum computing systems, and that the company is working on a new SDK and API for the IBM Quantum Experience, which gives anyone access to IBM's quantum processor via the IBM Cloud.

With the new API for Quantum Experience, more developers and programmers will be able to tap the five qubit system already accessible, without requiring a background in quantum physics. The new SDK however, which is to be released in the first half of this year, will allow for circuits of up to 20 qubits to be modelled by an upgraded simulator. Even that will be surpassed though as IBM also intends to introduce commercial IBM Q systems with about 50 qubits in the next few years. At this level of complexity it should be possible to show how quantum computers can surpass classical computers.



Source: IBM

First SHA-1 Collision Produced by Google

Category: Science & Technology
Posted: February 24, 2017 12:52PM
Author: Guest_Jim_*

There are many systems out there used to secure digital systems and content, and one of them has just been dealt a significant blow. The cryptographic hash function SHA-1 has been dealt its first collision, thanks to Google, effectively confirming it is no longer secure. Luckily there are better versions of the function out there already (SHA-256 and SHA-3, for example), but now it seems even more important for security professionals to move away from the 20 year old standard.

Cryptographic hashes are an important part of securing data on the Internet as the algorithms produce what should be unique message digests. If you want to check the authenticity of a file you download, and the source provides the digest, you can compare what the source provided against the digest your computer can make from what you downloaded, and if they match, you know you got what you wanted, and it was not compromised by some third-party. What Google has down is produced the first collision for Secure Hash Algorithm 1, which means it has generated two files, in this case two PDFs, that have different content but the same SHA-1 message digest. Google started from a paper published in 2013 that described a theoretical approach to creating the collision, and work started on creating a PDF prefix that would do the job. It took a lot of computation, but the collision has been produced.

For years it has been known and recognized that SHA-1 is not very secure, but it is still in use today to confirm website security certificates. However, Chrome 56 and newer will not consider any website with a SHA-1 certificate secured, and reacting to the news of the collision, Mozilla has accelerated its phase-in of depreciating SHA-1 to all Firefox 51 users.

You can find even more information about the collision and its potential impact at the second source link below.

Source: Google Security Blog and SHAttered.it

NASA Announces 7 Earth-Size Planets Found Around Single Star, with Some in Habitable Zone

Category: Science & Technology
Posted: February 22, 2017 03:02PM
Author: Guest_Jim_*

Last year three planets were discovered in the TRAPPIST-1 system and today it has been announced that, with the help of the Spitzer Space Telescope, four more planets have been found there, bringing the total to seven. Using Spitzer's data the sizes of these planets have been measured and first estimates of the inner-six's masses have also been made. Based on that information, these planets are most likely rocky planets, like Earth, and also Earth-like in size. While it will take more observations, it is possible all seven of these worlds possess liquid water on their surfaces, though only three of them are actually within the host-star's habitable zone. The seventh planet, which has not yet had its mass estimated, could be an icy, "snowball-like" world.

While these planets may have some similarities to Earth, the TRAPPIST-1 system is very different. The star is considered an ultra-cool dwarf, which means it is cool enough for even the nearest planet to have liquid water on its surface. In fact, all of these planets are closer to this star than Mercury is to the Sun. The orbits are also so close together that if someone were to stand on the surface of one planet, they may be able to make out geological features and even clouds on another. Being so close to the host star, it is possible the planets are tidally locked, meaning one side is always facing the star, just like how one side of the Moon always faces Earth.

For now we can expect at least NASA's Spitzer Space Telescope, Hubble Space Telescope, and the Kepler observatory, specifically designed for planet-hunting, to continue studying TRAPPIST-1, which is named for the Transiting Planets and Planetesimals Small Telescope in Chile that originally found the system. This new information will be used to help plan the missions for the upcoming James Webb Space Telescope, launching next year with the capability to detect the fingerprints of water, methane, oxygen, ozone, and other chemicals in the planets' atmosphere.



Source: NASA

Four-Stroke Engine Made Into Modular Reforming Reactor

Category: Science & Technology
Posted: February 21, 2017 11:42AM
Author: Guest_Jim_*

Hydrogen can be a potent fuel but one issue that has been deviling the adoption of it and the technology that can use it has been transporting the gas. In order to move the gas around like conventional fuels are would practically require a whole new infrastructure, but researchers at Georgia Institute of Technology have developed a solution. Instead of producing the hydrogen in one place and then transporting to where it will be used, they have created a reforming reactor that can be deploy at the point of use, and it just so happens to be related to the internal combustion engine.

Modern means of creating hydrogen for use in fuel cells involves temperatures of around 900 ºC, takes three water molecules to create one hydrogen molecule, and the resulting gas is low density. Wanting to design a better reactor, the researchers started thinking about the features it needed, and these included the ability to change the size of reactor vessel. Looking at existing mechanical systems, the researchers realized the internal combustion engine, with its over one hundred years of development, provides this feature, so they figured out how to make a four stroke engine into the CO2/H2 Active Membrane Piston (CHAMP) reactor.

In the first stroke, with the piston moving down, natural gas (methane) and stream are pulled into the cylinder, and once the piston reaches the bottom of the cylinder, the valve closes. Next the piston starts moving up, compressing the steam and methane, and the cylinder is also heated so that at 400 ºC a catalytic reaction is started, creating hydrogen and carbon dioxide. A selective membrane allows the hydrogen to exit the cylinder while the CO2 is pulled into a sorbent material mixed with the catalyst. Now when the piston lowers, reducing pressure as well, the CO2 escapes the sorbent so it can be expelled when the piston starts moving up again. While the process does produce carbon dioxide, it, like the hydrogen, can be captured for later use or long term storage.

Though the CHAMP reactor does resemble a four-stroke engine, it operates much more slowly, completing few cycles per minute, compared to conventional engines that run in the thousands of RPMs. This speed and other factors of the modular design can be altered, so the supply of hydrogen can match the immediate demand, at the source of the demand. Combined with the existing natural gas infrastructure and this system can be used to get as much hydrogen as is needed almost wherever it is needed, whether that is fuel cells for houses, refueling stations for fuel cell vehicles, or even larger systems for powering neighborhoods.

Source: Georgia Institute of Technology

Researchers Demonstrate Teaching Via Video Games

Category: Science & Technology
Posted: February 15, 2017 12:13PM
Author: Guest_Jim_*

To some people, video games only represent a waste of time that distracts players from more important and valuable ventures. Thankfully not everyone believes this and now researchers at the University of Texas at Dallas have even demonstrated some of the potential games have to do more than waste time. By adding realistic chemistry to Minecraft, the researchers found the student test-subjects were able to learn the science involved, without an in-class science instruction.

The name of the mod is Polycraft World and thanks to the chemistry professors that worked on the project as well, thousands of methods exist in it to produce over one hundred polymers from the thousands of chemicals available. Natural rubber can be used to make pogo sticks while crude oil can be processed with other materials to make a jetpack. A Wiki was also created for the students to look to, helping to find the right difficulty balance as making the game too easy will lead to players losing interest and being too hard will just frustrate them. Among the results were non-chemists building factories to build polyether ether ketones, which are very difficult to synthesize.

What the researchers want to see is the development of games that players can learn advanced subjects from, but can be played without accompanying any classroom learning. Right now though Polycraft World is also impacting classroom learning as it can monitor how players interact with it and how often they have to turn to a guide. This information on learning methods can be used to improve teaching methods to better help students.

Next the researchers want to add an economics portion to the Minecraft mod, and they are already working with economists to achieve this. Eventually players will be able to form governments and companies so a currency can be minted and distributed, with goods propping up the currency, hopefully forming a sustainable economy.

Source: University of Texas at Dallas

Researchers Image Atoms and Bonds Within Silicon

Category: Science & Technology
Posted: February 13, 2017 12:45PM
Author: Guest_Jim_*

Atomic force microscopy (AFM) is a rather extreme form of microscopy as it moves a probe with a single-atom tip over a surface to make measurements. The forces between materials cause the probe to be deflected by the atoms it moves over, and this deflection can be recorded and analyzed to visualize the sample with tremendous detail. Now researchers at the University of Alberta have applied AFM to study a silicon surface and to even fabricate patterns in the silicon.

While AFM has existed for quite some time now, it is not often used with silicon, and has never been used like this before because it can potentially damage the silicon, but the researchers decided to take the risk because of what success could offer. Eventually the researchers discovered ways to minimize these challenges, allowing them to move around individual silicon atoms. With this capability, atomically designed structures can be built, providing a new level of control over the electrons that will be flowing through them. The researchers were also able to use AFM to measure the electronic bonds between the silicon atoms, another first that allows new insight into how electrons behave as they travel across silicon structures.

The vision at least one of the researchers has is to see this work used to create ultra-fast and ultra-low-power silicon circuits that could potentially use ten thousand times less power than what is available today. It may take a while before we get there, but this step has now been made and it will not just be electronic computers that may benefit from this, but future quantum computers as well.

Source: EurekAlert!

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