an associate professor in Purdue's Dept. of Physics and Astronomy who led the research.""It is something like changing water from liquid to ice;
and some are familiar with the different magnetic phases that store data in our electronic devices and the liquid crystalline phases that are used to create an image on certain electronic displays,
but there are many other phases, Csáthy said. In 1937 physicist Lev Landau established a theoretical framework that explained
said Eduardo Fradkin, a professor of physics at the Univ. of Illinois at Urbana-Champaign and director of the Institute for Condensed Matter Theory at the Univ. of Illinois,
Csáthy specializes in the study of topological phases in semiconductors and works to discover and characterize rare topological phases.
His team employs novel investigative techniques for the study of electrons freely flowing in ultrapure gallium arsenide semiconductor crystals,
which is aligned a perfectly lattice of gallium and arsenic atoms that can capture electrons on a 2-D plane.
and the ultrapure crystals used in this research were grown by a group led by Michael Manfra, professor of physics and astronomy at Purdue.
Manfra also is a professor of both materials engineering and electrical and computer engineering. The gallium arsenide crystals grown using the molecular beam epitaxy technique serve as a model platform to explore the many phases that arise among strongly interacting electrons,
said Manfra, who also participated in the research and is a co-author of the paper."
"Our gallium arsenide is unique among semiconductors and other novel materials due to its extremely low level of disorder,
"Csáthy's team used unique equipment and techniques to take electricity to a temperature of 0. 012 K,
Csáthy's research team was focusing on the fractional quantum Hall state at quantum number 5/2,
but the stripes kept popping up and we would lose the fractional quantum Hall phase we were said investigating,
so that the data can be compared to the developing theories, Csáthy said
#Promising technique improves hydrogen production of affordable alternative to platinum Scientists have demonstrated that microwaves can help create nanostructured molybdenum disulfide (Mos2) catalysts with an improved ability to produce hydrogen.
The microwave-assisted strategy works by increasing the space, and therefore decreasing the interaction, between individual layers of Mos2 nanosheets.
This exposes a larger fraction of reactive sites along the edges of these surfaces where hydrogen can be produced.
Atomistic first-principles calculations show that the increase in spacing between the layers changes the electronic and chemical properties of these edge sites,
making them more effective in producing hydrogen. The strategy was demonstrated by a small group of researchers at the Center for Nanoscale Materials (CNM
a U s. Dept of energy (DOE) Office of Science User Facility based at DOE Argonne National Laboratory."
"The microwave-assisted strategy could be a viable way to design advanced molybdenum disulfide catalysts for hydrogen production
and hydrogen fuel cells,"said Yugang Sun, a nanoscience scientist in Argonne's Nanoscience and Technology Div."
"Microwave-synthesized nanostructured Mos2 exceeds the reactivity and stability levels of unmodified Mos2. Microwave-assisted synthesis is also a greener strategy
when compared to conventional heating methods.""Microwave energy is more efficient than conventional heating because it focuses its electromagnetic waves only on the material being treated
and provides quicker, more even heating of a material's interior and exterior surfaces. Conventional or surface heating is slower than microwave heating
and fails to achieve the desired result because it generates different temperatures in a material's interior compared with its surface area.
Mos2 is a common industrial catalyst that is used as a dry lubricant and in petroleum refining.
Earth-abundant materials that could provide low-cost alternatives to platinum-based catalysts. Platinum is an extremely efficient catalyst for splitting water into hydrogen and oxygen
#CRISPR brings precise control to gene expression Researchers have demonstrated the exceptional specificity of a new way to switch sequences of the human genome on
or off without editing the underlying genetic code. Originally discovered as an antiviral system in bacteria,
CRISPR/Cas9 is one of the hottest topics in genetic research today. By engineering a version of that system,
Those results raised concerns about the use of CRISPR technology in studying human diseases. As a potential solution
they inactivated the cutting function of Cas9 and attached proteins that control the packaging of the genome.
By unraveling or tightly bundling these regions of the genome, they could effectively turn them on and off.
Now, a team of researchers from Duke university have shown that these gene-controlling methods are capable of the high degree of precision required for basic science and medical research.
associate professor of biomedical engineering at Duke Univ."Many labs across the world are using these tools on the assumption that they're getting specific effects,
These experiments show exceptional specificity, demonstrating that the technology is capable of targeting single sequences of the genome."
"The power to control the genome's switches would be especially important for studying and potentially treating human diseases such as cancer, cardiovascular disease, neurodegenerative conditions and diabetes,
which can be driven by mutations in control regions of the genome. The hope is that overriding one of these switches could uncover
and fix the root causes of many diseases. It could also help researchers understand and change how different people respond to drugs.
But only if the CRISPR technique is specific enough. Soon after CRISPR was described first for editing human genes,
This presents problems for gene therapy treatments and fundamental science projects where researchers want to alter the function of specific genes without causing unintended side effects.
"said Timothy Reddy, assistant professor of biostatistics and bioinformatics at Duke.""Finding a change in sequence
if you're focusing on one concentrated area in the genome. But looking at how turning off one enhancer switch affects the activity
and structure of the whole genome requires more specialized techniques.""Gersbach turned to Reddy and colleague Gregory Crawford,
who all work together in adjacent laboratories and offices in Duke's Center for Genomic and Computational biology, for help with these more specialized techniques.
Reddy has focused his career on investigating how gene switches work across the human genome, how those switches differ between individuals and the implications of these insights for human traits and diseases.
Crawford, associate professor of pediatrics, has spent more than a decade developing techniques to identify control regions across the genome
and how they vary between cell types, during development or in response to drug treatment."
change the activity of many switches across the genome simultaneously, creating thousands of off-target effects,
"It fell to Pratiksha Thakore, a Phd student in Gersbach's lab, to integrate the expertise of all three laboratories for studying the specificity of CRISPR in controlling these switches.
"By integrating genomics and genome engineering, we have developed a method to comprehensively interrogate how this genetic silencing system works
Other participants include scientists from Manipal University, India; GSI-Giessen, Germany; Justus Liebig University Giessen, Germany;
Japan Atomic energy agency; and the joint Institute for Nuclear research in Russia. The results are published in the journal Physics Letters B. The Lab Dawn Shaughnessy, Ken Moody,
For the experiment, the scientists shot at a 300-nanometer-thick foil of curium with accelerated calcium nuclei.
and analyzed using special filters composed of electrical and magnetic fields. The scientists used all of the decay products detected to identify the new isotope that has been created.
and Hollywood A team of researchers at MIT Computer science and Artificial intelligence Lab (CSAIL) has believed long that wireless signals like Wifi can be used to see things that are invisible to the naked eye.
and body movements as subtle as the rise and fall of a person chest from the other side of a house, allowing a mother to monitor a baby breathing
the team presents a new technology called RF Capture that picks up wireless reflections off the human body to see the silhouette of a human standing behind a wall.
and even distinguish between 15 different people through a wall with nearly 90 percent accuracy.
From heating bills to Hollywood Researchers say the technology could have major implications for everything from gaming and filmmaking to emergency response and eldercare.
and move in a specific room full of cameras, says Phd student Fadel Adib, who is lead author on the new paper.
F Capture would enable motion capture without body sensors and could track actorsmovements even if they are behind furniture or walls.
The device's motion-capturing technology makes it equally valuable for smart homes, according to MIT professor and paper co-author Dina Katabi. ee working to turn this technology into an in-home device that can call 911
if it detects that a family member has fallen unconscious, says Katabi, director of the Wireless@MIT center. ou could also imagine it being used to operate your lights and TVS,
or to adjust your heating by monitoring where you are in the house. Future versions could be integrated into gaming interfaces,
allowing you to interact with a game from different rooms or even trigger distinct actions based on
which hand you move. he possibilities are vast, says Adib, whose other co-authors include MIT professor Frédo Durand, Phd student Chen-Yu Hsu,
and undergraduate intern Hongzi Mao. ee just at the beginning of thinking about the different ways to use these technologies.
How it works The device works by transmitting wireless signals that traverse the wall and reflect off a person body back to the device.
The emitted radiation is approximately 1/10,000 the amount given off by a standard cellphone.
The device captures these reflections and analyzes them in order to see the person silhouette. The key challenge,
however, is that different individuals and, for that matter, different body parts all reflect the same signal. Which raises the question:
he data you get back from these reflections are very minimal, says Katabi. owever, we can extract meaningful signals through a series of algorithms we developed that minimize the random noise produced by the reflections.
The technology operates in two stages: First, it scans 3-D space to capture wireless reflections off objects in the environment,
including the human body. However, since only a subset of body parts reflect the signal back at any given point in time,
the device then monitors how these reflections vary as someone moves in the environment and intelligently stitches the person reflections across time to reconstruct his silhouette into a single image.
Team members are in the process of spinning out a product called Emerald that aims to detect, predict and prevent falls among the elderly.
In August the team presented Emerald to President Obama as part of the White house first annual Demo Day. n the same way that cellphones and Wifi routers have become indispensable parts
#How wireless x-ray vision could power virtual reality A team of researchers at Massachusetts institute of technology (MIT) Computer science
and Artificial intelligence Lab (CSAIL) has believed long that wireless signals like Wi-fi can be used to see things that are invisible to the naked eye.
and body movements as subtle as the rise and fall of a person chest from the other side of a house, allowing a mother to monitor a baby breathing
the team presents a new technology called RF Capture that picks up wireless reflections off the human body to see the silhouette of a human standing behind a wall.
and even distinguish between 15 different people through a wall with nearly 90 percent accuracy.
From heating bills to Hollywood Researchers say the technology could have major implications for everything from gaming and filmmaking to emergency response and eldercare.
and move in a specific room full of cameras, says Phd student Fadel Adib, who is lead author on the new paper.
F Capture would enable motion capture without body sensors and could track actorsmovements even if they are behind furniture or walls.
The device's motion-capturing technology makes it equally valuable for smart homes, according to MIT professor and paper co-author Dina Katabi. ee working to turn this technology into an in-home device that can call 911
if it detects that a family member has fallen unconscious, says Katabi, director of the Wireless@MIT center. ou could also imagine it being used to operate your lights and TVS,
or to adjust your heating by monitoring where you are in the house. Future versions could be integrated into gaming interfaces,
allowing you to interact with a game from different rooms or even trigger distinct actions based on
which hand you move. he possibilities are vast, says Adib, whose other co-authors include MIT professor Frédo Durand, Phd student Chen-Yu Hsu,
and undergraduate intern Hongzi Mao. ee just at the beginning of thinking about the different ways to use these technologies.
How it works The device works by transmitting wireless signals that traverse the wall and reflect off a person body back to the device.
The emitted radiation is approximately 1/10,000 the amount given off by a standard cellphone.
The device captures these reflections and analyzes them in order to see the person silhouette. The key challenge,
however, is that different individualsnd, for that matter, different body partsll reflect the same signal. Which raises the question:
he data you get back from these reflections are very minimal, says Katabi. owever, we can extract meaningful signals through a series of algorithms we developed that minimize the random noise produced by the reflections.
The technology operates in two stages: First, it scans 3-D space to capture wireless reflections off objects in the environment,
including the human body. However, since only a subset of body parts reflect the signal back at any given point in time,
the device then monitors how these reflections vary as someone moves in the environment and intelligently stitches the person reflections across time to reconstruct his silhouette into a single image.
Team members are in the process of spinning out a product called Emerald that aims to detect, predict and prevent falls among the elderly.
In August the team presented Emerald to President Obama as part of the White house first annual Demo Day. n the same way that cellphones and Wifi routers have become indispensable parts
#New design points a path to the ltimatebattery Scientists have developed a working laboratory demonstrator of a lithium-oxygen battery
or lithium-air, batteries have been touted as the'ultimate'battery due to their theoretical energy density, which is ten times that of a lithium-ion battery.
Such a high energy density would be comparable to that of gasoline -and would enable an electric car with a battery that is a fifth the cost and a fifth the weight of those currently on the market to drive from London to Edinburgh on a single charge.
However, as is the case with other next-generation batteries, there are several practical challenges that need to be addressed before lithium-air batteries become a viable alternative to gasoline.
Now, researchers from the Univ. of Cambridge have demonstrated how some of these obstacles may be developed overcome,
and a lab-based demonstrator of a lithium-oxygen battery which has increased higher capacity energy efficiency and improved stability over previous attempts.
Their demonstrator relies on a highly porous, 'fluffy'carbon electrode made from graphene (comprising one-atom-thick sheets of carbon atoms),
and additives that alter the chemical reactions at work in the battery, making it more stable and more efficient.
While the results, reported in Science, are promising, the researchers caution that a practical lithium-air battery still remains at least a decade away."
"What we've achieved is a significant advance for this technology and suggests whole new areas for researche haven't solved all the problems inherent to this chemistry,
but our results do show routes forward towards a practical device, "said Prof. Clare Grey of Cambridge's Dept. of Chemistry, the paper's senior author.
Many of the technologies we use every day have been getting smaller, faster and cheaper each yearith the notable exception of batteries.
Apart from the possibility of a smartphone which lasts for days without needing to be charged,
the challenges associated with making a better battery are holding back the widespread adoption of two major clean technologies:
electric cars and grid-scale storage for solar power.""In their simplest form, batteries are made of three components:
a positive electrode, a negative electrode and an electrolyte,''said Dr. Tao Liu, also from the Dept. of Chemistry,
and the paper's first author. In the lithium-ion (Li-ion) batteries we use in our laptops and smartphones,
the negative electrode is made of graphite (a form of carbon), the positive electrode is made of a metal oxide, such as lithium cobalt oxide,
and the electrolyte is a lithium salt dissolved in an organic solvent. The action of the battery depends on the movement of lithium ions between the electrodes.
Li-ion batteries are light but their capacity deteriorates with age, and their relatively low energy densities mean that they need to be recharged frequently.
Over the past decade, researchers have been developing various alternatives to Li-ion batteries, and lithium-air batteries are considered the ultimate in next-generation energy storage, because of their extremely high energy density.
However, previous attempts at working demonstrators have had low efficiency, poor rate performance, unwanted chemical reactions, and can only be cycled in pure oxygen.
What Liu, Grey and their colleagues have developed uses a very different chemistry than earlier attempts at a non-aqueous lithium-air battery
relying on lithium hydroxide (Lioh) instead of lithium peroxide (Li2o2. With the addition of water and the use of lithium iodide as a'mediator',their battery showed far less of the chemical reactions
which can cause cells to die, making it far more stable after multiple charge and discharge cycles.
By precisely engineering the structure of the electrode, changing it to a highly porous form of graphene,
adding lithium iodide, and changing the chemical makeup of the electrolyte, the researchers were able to reduce the'voltage gap'between charge
and discharge to 0. 2 volts. A small voltage gap equals a more efficient batteryrevious versions of a lithium-air battery have managed only to get the gap down to 0. 5 to 1. 0 V
whereas 0. 2 V is closer to that of a Li-ion battery, and equates to an energy efficiency of 93%.
%The highly porous graphene electrode also greatly increases the capacity of the demonstrator, although only at certain rates of charge and discharge.
Other issues that still have to be addressed include finding a way to protect the metal electrode
so that it doesn't form spindly lithium metal fibers known as dendrites, which can cause batteries to explode
if they grow too much and short-circuit the battery. Additionally, the demonstrator can only be cycled in pure oxygen,
while the air around us also contains carbon dioxide, nitrogen and moisture, all of which are generally harmful to the metal electrode."
"There's still a lot of work to do, "said Liu.""But what we've seen here suggests that there are ways to solve these problemsaybe we've just got to look at things a little differently.""
""While there are still plenty of fundamental studies that remain to be done, to iron out some of the mechanistic details,
the current results are extremely excitinge are still very much at the development stage, but we've shown that there are solutions to some of the tough problems associated with this technology,
"said Grey o
#New concepts emerge for generating clean, inexpensive fuel from water An inexpensive method for generating clean fuel is the modern-day equivalent of the philosopher's stone.
One compelling idea is to use solar energy to split water into its constituent hydrogen and oxygen and then harvest the hydrogen for use as fuel.
But splitting water efficiently turns out to be not so easy. Now two scientists at the Univ. of Chicago's Institute for Molecular Engineering (IME) and the Univ. of Wisconsin have made an important contribution to the effort,
Kyoung-Shin Choi is a professor of chemistry at the University of Wisconsin, Madison, and an experimentalist.
Giulia Galli is Liew Family Professor of Electronic Structure and Simulations at the IME and a theorist.
which an electrode used for splitting water absorbs solar photons while at the same time improving the flow of electrons from one electrode to another.
"Excited electrons When building a sun-capturing electrode, scientists aim to use as much of the solar spectrum as possible to excite electrons in the electrode to move from one state to another,
where they will be available for the water-splitting reaction. Equally important, but a separate problem entirely, the electrons need to move easily from the electrode to a counter-electrode,
creating a flow of current. Until now, scientists have had to use separate manipulations to increase photon absorption
if they heated an electrode made of the semiconducting compound bismuth vanadate to 350 degrees Celsius
Nitrogen's role Galli and former graduate student Yuan Ping, now a post-doc at Caltech, found that the nitrogen was acting on the electrode in several ways.
Finally, that nitrogen lowered the energy needed to kick electrons into the state in which they were available to split water.
This meant that more of the solar energy could be used by the electrode.""Now we understand what's going on at the microscopic level,
#Researchers create transplantation model for 3-D printed constructs Using sugar, silicone and a 3-D printer,
a team of bioengineers at Rice Univ. and surgeons at the Univ. of Pennsylvania have created an implant with an intricate network of blood vessels that points toward a future of growing replacement tissues and organs for transplantation.
The research may provide a method to overcome one of the biggest challenges in regenerative medicine:
or weeks to grow in the lab prior to surgery. The new study was performed by a research team led by Jordan Miller, assistant professor of bioengineering at Rice,
and Pavan Atluri, assistant professor of surgery at Penn. The study showed that blood flowed normally through test constructs that were connected surgically to native blood vessels.
The report was published in Tissue Engineering Part C: Methods. Miller said one of the hurdles of engineering large artificial tissues,
In this study, we are taking the first step toward applying an analogy from transplant surgery to 3-D printed constructs we make in the lab. iller
and his team thought long-term about what the needs would be for transplantation of large tissues made in the laboratory. hat a surgeon needs
in order to do transplant surgery isn just a mass of cells; the surgeon needs a vessel inlet
and an outlet that can be connected directly to arteries and veins, he said. Bioengineering graduate student Samantha Paulsen and research technician Anderson Ta worked together to develop a proof-of-concept construct small silicone gel about the size of a small candy gummy bearsing 3
-D printing. But rather than printing a whole construct directly, the researchers fabricated sacrificial templates for the vessels that would be inside the construct.
It a technique pioneered by Miller in 2012nd inspired by the intricate sugar glass cages crafted by pastry chefs to garnish desserts.
Using an open-source 3-D printer that lays down individual filaments of sugar glass one layer at a time
leaving behind a network of small channels in the silicone. hey don yet look like the blood vessels found in organs,
but they have some of the key features relevant for a transplant surgeon, Miller said. e created a construct that has one inlet and one outlet,
which are about 600 to 800 um. ollaborating surgeons at Penn in Atluri group connected the inlet
and unobstructed for up to three hours. his study provides a first step toward developing a transplant model for tissue engineering where the surgeon can directly connect arteries to an engineered tissue,
use it to drive turbines and then be reheated to continue the cycle. Most commonly this might be done over a 24-hr period, with variable levels of solar-powered electricity available at any time of day
as dictated by demand. The findings have been published in Chemsuschem. The work was supported by the Sunshot Initiative of the U s. Dept of energy,
and done in collaboration with researchers at the Univ. of Florida. Conceptually, all of the energy produced could be stored indefinitely
and used later when the electricity is needed most. Alternatively, some energy could be used immediately and the rest stored for later use.
Storage of this type helps to solve one of the key factors limiting the wider use of solar energyy eliminating the need to use the electricity immediately.
The underlying power source is based on production that varies enormously not just night and day, but some days,
or times of day, that solar intensity is more or less powerful. Many alternative energy systems are constrained by this lack of dependability and consistent energy flow.
Solar thermal electricity has been of considerable interest because of its potential to lower costs. In contrast to conventional solar photovoltaic cells that produce electricity directly from sunlight, solar thermal generation of energy is developed as a large power plant in
which acres of mirrors precisely reflect sunlight onto a solar receiver. That energy has been used to heat a fluid that in turn drives a turbine to produce electricity.
Such technology is appealing because it safe long-lasting, friendly to the environment and produces no greenhouse gas emissions.
Cost, dependability and efficiency have been the primary constraints. ith the compounds wee studying, there significant potential to lower costs and increase efficiency, said Nick Auyeung, an assistant professor of chemical engineering in the OSU College of Engineering, corresponding author on this study,
and an expert in novel applications and use of sustainable energy. n these types of systems, energy efficiency is closely related to use of the highest temperatures possible,
Auyeung said. he molten salts now being used to store solar thermal energy can only work at about 600 degrees centigrade,
and also require large containers and corrosive materials. The compound wee studying can be used at up to 1, 200 degrees,
and might be twice as efficient as existing systems. his has the potential for a real breakthrough in energy storage,
According to Auyeung, thermochemical storage resembles a battery, in which chemical bonds are used to store and release energyut in this case,
the transfer is based on heat, not electricity. The system hinges on the reversible decomposition of strontium carbonate into strontium oxide and carbon dioxide,
In comparison to existing approaches, the new system could also allow a 10-fold increase in energy densityt physically much smaller
which would drive a turbine to produce electricity, and then residual heat could be used to make steam to drive yet another turbine.
In laboratory tests, one concern arose when the energy storage capacity of the process declined after 45 heating and cooling cycles, due to some changes in the underlying materials.
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