By comparison Universal serial bus (USB) chargers for small electronic devices provide about 5v of power. e were aiming for the highest energy efficiency we could achievesays Hawkes. e had been getting energy efficiency around 6 to 10 percent
but many of the same molecules that support axonal spikes are also present in the dendrites.
Previous research using dissected brain tissue had demonstrated that dendrites can use those molecules to generate electrical spikes themselves
and see if you can hit a dendritehe adds. ost of the time you can t. ut Smith built his own two-photon microscope system to make things easier.
and co-author on the paper. e want to know how nature builds these catalystsâ##from a chemist s perspective these are really strange things. he bacterial catalysts are organized based on precisely clusters of iron and sulfur atoms with side groups of cyanide and carbon monoxide.
Those molecules are highly toxic unless properly controlled Britt notes. The cyanide and carbon monoxide groups were known to come from the amino acid tyrosine Britt says.
Jon Kuchenreuther a postdoctoral researcher in Britt s laboratory used a technique called electron paramagnetic resonance to study the structure of the intermediate steps.
The tyrosine is attached to a cluster of four iron atoms and four sulfur atoms then cut loose leaving the cyanide
and carbon monoxide groups behind. eople think of radicals as dangerous but this enzyme directs the radical chemistry
Lithium-sulfur batteries are a promising alternative to today s lithium-ion batteries. here is currently a great need for high-energy long-life
Lithium-sulfur batteries could potentially offer about five times the energy density of today s typically used lithium-ion batteriessays Yingchao Yu a Phd student with Abruã a
which is when the polysulfide chains in the battery s cathode (positive end) dissolve in the electrolyte the ionizing liquid that allows electrons to flow.
or the batteries have no charge remaining. n addition to the applications discussed above such technology could be extended to other radiations such as magnetic resonance imaging (MRI) and light detection and ranging (LIDAR)
. ut we ve found an easy way to do it. nstead of storing energy in chemical reactions the way batteries do upercapsstore electricity by assembling ions on the surface of a porous material.
Supercapacitors still lag behind the electrical energy storage capability of lithium-ion batteries so they are too bulky to power most consumer devices.
because it reacts readily with some of chemicals in the electrolytes that provide the ions that store the electrical charge.
The tunable dielectric and its properties were envisioned first on paper tested on the computer created in the lab atom by atom patterned into a capacitor device
An atomic-resolution electron micrograph reveals its design. It looks like bricks and mortar with very specific spacing between the well-defined interfaces.
Higher energy light waves including most of the visible light spectrum are wasted as heat while lower energy waves simply pass through the solar panel. n theory conventional single-junction solar cells can only achieve an efficiency level of about 34 percent
but in practice they don t achieve thatsays study co-author Paul Braun a professor of materials science at Illinois. hat s
By adding modified single-atom-thick graphene nanoribbons (GNRS) to thermoplastic polyurethane (TPU) the team at Rice made it 1000 times harder for gas molecules to escape Tour says.
Because gas molecules cannot penetrate GNRS they are faced with a ortuous pathto freedom he says.
But the overlapping 200-to 300-nanometer-wide ribbons dispersed so well that they were nearly as effective as large-sheet graphene in containing gas molecules.
That s because gas molecules go through rubber or plastictour says. t took years for scientists to figure out how to make a plastic bottle for soda.
and in some ways it s the reverse problemhe says. xygen molecules get in through plastic and make the beer go bad.
The challenge for Angel Mart assistant professor of chemistry and bioengineering at Rice university and his team of student researchers was to get their large metallic particles through the much smaller pores of a zeolite cage.
and small poresmart says. he pores are big enough at about 7. 4 angstrom for most gas-phase molecules to enter.
That ranges from less than 1000 nanoseconds for water and ammonia to quite long4000-plus nanoseconds for pyridine.
With the new findings researchers see potential for very large sheets of h-BN only a few atoms thick made by scalable vapor deposition methods. e think this opens up new opportunities for two-dimensional
or Java##to rogramhow DNA molecules interact in a test tube or cell. A team has developed a programming language for chemistry that it hopes will streamline efforts to design a network that can guide the behavior of chemical-reaction mixtures in the same way that embedded electronic controllers guide cars robots and other devices.
and use it to write programs that direct the movement of tailor-made molecules. e start from an abstract mathematical description of a chemical system
and then use DNA to build the molecules that realize the desired dynamicssays corresponding author Georg Seelig am assistant professor of electrical engineering
and other organisms already have complex networks of nano-sized molecules that help to regulate cells and keep the body in check.
Scientists now are finding ways to design synthetic systems that behave like biological ones with the hope that synthetic molecules could support the body s natural functions.
To that end a system is needed to create synthetic DNA molecules that vary according to their specific functions.
but future uses could include using this framework to make molecules that self-assemble within cells
#This electron accelerator is smaller than a grain of rice Stanford university rightoriginal Studyposted by Mike Ross-Stanford on September 30 2013researchers have used a laser to accelerate electrons at a rate 10 times higher than conventional technology
and cost of future high-energy particle colliders for exploring the world of fundamental particles and forcessays Joel England a physicist with the US Department of energy s SLAC National Accelerator Laboratory at Stanford university who led the experiments. t could also help enable compact accelerators and X-ray devices for security
scanning medical therapy and imaging and research in biology and materials science. ecause it employs commercial lasers
and deliver a million more electron pulses per second. This initial demonstration reported in the journal Nature achieved an acceleration gradient
or amount of energy gained per length of the accelerator of 300 million electronvolts per meter.
Today s accelerators use microwaves to boost the energy of electrons. Researchers have been looking for more economical alternatives and this new technique
which uses ultrafast lasers to drive the accelerator is a leading candidate. Particles are accelerated generally in two stages.
First they are boosted to nearly the speed of light. Then any additional acceleration increases their energy but not their speed;
In the accelerator-on-a-chip experiments electrons are accelerated first to near light-speed in a conventional accelerator.
Infrared laser light shining on the pattern generates electrical fields that interact with the electrons in the channel to boost their energy.
Turning the accelerator on a chip into a full-fledged tabletop accelerator will require a more compact way to get the electrons up to speed before they enter the device.
It simultaneously reports in Physical Review Letters its success in using a laser to accelerate lower energy electrons.
Applications for these new particle accelerators would go well beyond particle physics research. Byer says laser accelerators could drive compact X-ray free-electron lasers comparable to SLAC s Linac Coherent light Source that are all-purpose tools for a wide range of research.
Another possible application is small portable X-ray sources to improve medical care for people injured in combat as well as to provide more affordable medical imaging for hospitals and laboratories.
The researchers were able to stabilize the light s frequency by developing a silica glass chip resonator with a specially designed path for the photons in the shape of
if we made the photons travel a longer path the whole device would become more stablesays Hansuek Lee a senior researcher in Vahala s lab
In the new design photons are applied to an outer ring of the spiraled resonator with a tiny light-dispensing optic fiber;
the photons subsequently travel around four interwoven Archimedean spirals ultimately closing the path after traveling more than a meter in an area about the size of a quarterâ##a journey 100 times longer than achieved in previous designs.
The work was conducted at the Geosoilenvirocars beamline operated by University of Chicago at the Advanced Photon Source housed at Argonne.
The US Department of energy Office of Science funded the use of the Advanced Photon Source. Study authors contributed from the Ecole Normale Supã rieure in France Universitã de Granoble in France the University of Chicago and UMET CNRS â##Universitã Lille 1 and UC Riverside.
Inside that murky vial attached to the negative electrode bacteria feast on particles of organic waste
and convert it into biological fuel their excess electrons flow into the carbon filaments and across to the positive electrode
which is made of silver oxide a material that attracts electrons. The electrons flowing to the positive node gradually reduce the silver oxide to silver storing the spare electrons in the process.
After a day or so the positive electrode has absorbed a full load of electrons and has largely been converted into silver says Xing Xie an interdisciplinary researcher.
At that point it is removed from the battery and re-oxidized back to silver oxide releasing the stored electrons.
Engineers estimate that the microbial battery can extract about 30 percent of the potential energy locked up in wastewater.
#Earth s inner core spins faster than rest of planet University of Leeds rightoriginal Studyposted by Ben Jones-U. Leeds on September 17 2013the Earth s
while the outer core comprising mainly molten iron spins westwards at a slower pace. Although Edmund Halley who also discovered the famous comet showed the westward-drifting motion of the Earth s geomagnetic field in 1692 it is the first time that scientists have been able to link the way the inner core spins to the behavior of the outer core.
The planet behaves in this way because it is responding to the Earth s geomagnetic field.
A nanometer is a billionth of a meter the width of a double-stranded DNA molecule.
#Glass just two atoms thick shatters world record Cornell University rightoriginal Studyposted by Anne Ju-Cornell on September 12 2013a aneof glass so impossibly thin that its individual silicon
and oxygen atoms are clearly visible via electron microscopy is the world s thinnest sheet of glass. The glass sheet will be recorded in the Guinness World records 2014 Edition.
Just two atoms in thickness the glass was an accidental discovery says David A. Muller professor of applied
Now the Cornell scientists have produced a picture of individual atoms of glass and they found that it strikingly resembles a diagram drawn in 1932 by W. H. Zachariasenâ##a longstanding theoretical representation of the arrangement of atoms in glass. his is the work that when
I look back at my career I will be most proud ofmuller says. t s the first time that anyone has been able to see the arrangement of atoms in a glass. hat s more two-dimensional glass could someday find a use in transistors by providing a defect-free ultra-thin material that could improve the performance of processors
in computers and smartphones. The National Science Foundation funded the work at Cornell. Source: Cornell Universityyou are free to share this article under the Creative Commons Attribution-Noderivs 3. 0 Unported license 3
Next the researchers used a technique called two-photon lithography to turn that design into a three-dimensional polymer lattice.
and then watching the microscopic matchstick particles move towards it a phenomenon known as chemotaxis. For the purposes of this experiment the researchers placed silica##manganese oxide eadson the matchstick material and introduced hydrogen peroxide as the chemical fuel in one particular place.
or under Brownian motion but the matchsticks were propelled clearly rapidly towards the chemical gradient where the hydrogen peroxide could be found.
The reaction was so strong that more than half of the matchstick particles did not reverse their orientation once over their 90 seconds of travel towards the hydrogen peroxide
and Brownian rotation. e choose high aspect ratio rodlike particles as they are a favorable geometry for chemotactic swimmers as seen for example in nature in the shapes of certain motile organismssays Bon. e placed the engine
and requires no bulky spectrometers it is quite practical and could scan many people and their belongings quicklysays Marcos Dantus chemistry professor at Michigan State university. ot only does it detect the explosive material
The low energy laser is safe to use on luggage as well as passengers Dantus says. For decades scientists have been working to develop lasers that are powerful enough for detection
#Quantum system teleports an atom For the first time physicists have transmitted an atom from one location to another inside an electronic chip.
and more functional electronic chips says Arkady Fedorov of the ARC Centre of Excellence for Engineered Quantum systems
and in more efficient information processing based on the laws of quantum physics. Researchers from ETH Zurich also contributed to the study
Reddy says. y allowing safe operation over a wide range of temperatures without compromising on high energy,
which conducts ions between a battery electrodes, that won break down when the heat is on. Another issue has been finding a separator that won shrink at high temperatures and lead to short circuits.
while allowing ions to pass through). ur innovation has been to identify an unconventional electrolyte/separator system that remains stable at high temperatures,
Imprinted genes use molecules that bind to DNA (epigenetic tags) to quiet one half and let the other lead.
One of the many counterintuitive and bizarre insights of quantum mechanics is that even in a vacuum
Low levels of noise known as quantum fluctuations are always present. Always that is unless you can pull off a quantum trick.
The group engineered the miniature silicon system that produces a type of light that is quieter at certain frequencies#meaning it has fewer quantum fluctuations#than
#This system should enable a new set of precision microsensors capable of beating standard limits set by quantum mechanics#says Oskar Painter a professor of applied physics at Caltech
When photons-particles of light-strike the beams they cause the beams to vibrate. And the particulate nature of the light introduces quantum fluctuations that affect those vibrations.
Typically such fluctuations mean that in order to get a good reading of a signal you would have to increase the power of the light to overcome the noise.
so that the light and beams interact strongly with each other#so strongly in fact that the beams impart the quantum fluctuations they experience back on the light.
what quantum mechanics really says: light is neither a particle nor a wave; you need both explanations to understand this experiment#says Safavi-Naeini.#
#You need the particle nature of light to explain these quantum fluctuations and you need the wave nature of light to understand this interference.#
#The National Science Foundation the Gordon and Betty Moore Foundation the Air force Office of Scientific research and the Kavli Nanoscience Institute at Caltech supported the work.
and the ability to recharge in seconds the drawback of existing supercapacitors is their low energy-storage-to-volume ratio#known as energy density.
Low energy density of five to eight watt-hours per liter means supercapacitors are unfeasibly large or must be recharged frequently.
when graphite is broken down into layers one atom thick is very strong chemically stable and an excellent conductor of electricity.
##Shifty#neutrinos hint at antimatter mystery Boston University Duke university Stony Brook University University of Pittsburgh University of Rochester University of Washington Posted by Leonor Sierra-Rochester
ROCHESTER/STONY BROOK (US)# Scientists have announced the first definitive observation of the transformation of muon neutrinos to electron neutrinos#a type of neutrino oscillation that had never been observed.#
#In 1998 the discovery of neutrino oscillation in the atmospheric neutrinos by the Super-Kamiokande experiment led us to a new journey into the fascinating and mysterious world of neutrinos
#This discovery of electron neutrino appearance from muon neutrinos by the T2k experiment opens another critical door in our journey to unveil the secrets of our universe.#
when matter and antimatter were created in equal amounts in the Big bang? Somehow this balance changed over time to a dominance of matter.
The experiment shows that researchers can now accurately observe the type of neutrino oscillation that will need to be studied in detail in future experiments aiming to measure CP violation explains Steven Manly professor of physics at the University of Rochester and part of the collaboration.
whether or not it would be feasible to explore CP violation in neutrinos. CP violation has only been observed in another type of particle quarks (for
which Nobel prizes were awarded in 1980 and 2008) never in neutrinos. The observed type of neutrino oscillation is sensitive to CP violation
and the T2k experiment will try to observe this process in neutrinos over coming years.
It could be that the asymmetry between matter and antimatter lies with neutrinos which is why observing CP violation in neutrinos would be exciting Manly adds.#
#Our goal now is to push to better understand the errors in the measurements and continue to collect sufficient data to explore this possible CP violation.#
#One in a trillionthe T2k experiment based in Tokai Japan expects to collect 10 times more data in the near future including data with an antineutrino beam.
Manly explains that neutrinos are notoriously difficult to study and the oscillation that the researchers seek can be mimicked by other processes.
For that reason the University of Rochester group has focused on understanding these other processes to ensure that what is measured is really the neutrino oscillation they have sought.
In 2011 the collaboration announced the first hints of this process. The researchers have gathered now 3. 5 times more data
The probability that random statistical fluctuations alone would produce the observed excess of electron neutrinos is less than one in a trillion.
In the T2k experiment a muon neutrino beam is produced in the Japan Proton accelerator Research Complex called J-PARC located in Tokai village Ibaraki Prefecture on the east coast of Japan.
The neutrino beam is monitored by a detector complex in Tokai and aimed at the gigantic Super-Kamiokande underground detector in Kamioka near the west coast of Japan 295 kilometers (185 miles) away from Tokai.
An analysis of the data from the Super-Kamiokande detector associated with the neutrino beam time from J-PARC reveals that there are more electron neutrinos (a total of 28 events) than would be expected (4. 6 events) without this new process.
the particles heat up so quickly they instantly vaporize water and create steam. The technology has an overall energy efficiency of 24 percent.
Discovered about a decade ago graphene is a sheet of carbon just one atom thick.
In the new experiments, the Rice lab mixed graphene nanoribbons and tin oxide particles about 10 nanometers wide in a slurry with a cellulose gum binder and a bit of water, spread it on a current collector
GNRS are a single atom thick and thousands of times longer than they are wide.
but also help deliver lithium ions to the nanoparticles. Major hurdle Lab tests showed initial charge capacities of more than 1
Lithium ions tend to expand the material they inhabit, and the material contracts when theye pulled away.
break down and lose their ability to store ions. Other labs at Rice have made breakthroughs that help solve the expansion problem by breaking treated silicon into a powder
he adds. ince the tin oxide particles are only a few nanometers in size and permitted to remain that way by being dispersed on GNR surfaces,
In its perfect crystalline form, graphene (a one-atom-thick carbon layer) is the strongest material ever measured
This is due to all the atoms in graphene being surface atoms, so surface damage that would normally not degrade the strength of 3d materials can completely destroy the strength of 2d materials. owever with appropriate processing that avoids surface damage,
Isotopic analysis using secondary ion mass spectrometry was carried out at UCLA. To determine if these inclusions were actually biological in origin the researchers looked at 15 different samples of Farrel Quartzite
and determined their stable carbon isotope ratios. The percentage of carbon 13 in the microfossils was produced indicative of material by biological processes.
Stable carbon isotope analysis can determine the biological origin of these microfossils because they used carbon dioxide to create energy
#First boson laser could save power Stanford university University of Michigan rightoriginal Studyposted by Bjorn Carey-Stanford on May 24 2013stanford (US)# Scientists have demonstrated a revolutionary electrically driven polariton laser
The new system however makes use of the unique physical properties of bosons subatomic particles that scientists have attempted to incorporate into lasers for decades.#
Charged particles such as electrons exist in discontinuous energy levels like rungs on a ladder. An electron provided with enough energy can become excited
and#jump up to a higher energy level. Excited electrons can spontaneously fall down to an available lower energy level shooting off the difference in energy as a bit of light called a photon.
The amount of time that passes before an excited electron drops down and releases a photon is usually random.
However Einstein predicted that if an electron in an upper energy level was exposed to a photon with proper energy the electron would instantly fall down
and release a second photon identical to the first one. A laser keeps this process going by continually providing energy for electrons to move into higher energy levels.
As more and more electrons are stimulated to release photons the additional photons stimulate more and more electrons. Some of the photons are allowed to escape from the device to serve a purpose such as reading data off a CD or etching a circuit board.
The process however is inefficient. There is a hard limit to the number of electrons that can inhabit a given energy level at any given time
and conventional lasers waste energy unnecessarily exciting electrons to higher energy levels even when the lower levels are too full to accept the excited electrons
when they fall. Exciting excitonskim s polariton laser however pairs electrons with so-called#holes#to form another type of particle an exciton.
A hole is a gap where an electron could exist in a structure and is treated by physicists as a real separate particle.
These excitons are bosons and an unlimited number of them can inhabit any given energy level.
Using bosons in lasers has been a scientific goal for decades but Yamamoto s team is the first to successfully build an electrically driven laser using bosons.
The result was reproduced recently and confirmed by scientists at the University of Michigan who published their work in the journal Physical Review Letters.)
This change drastically reduces the amount of power required to run the laser. The current iteration of the polariton laser requires two to five times less energy than a comparable conventional laser
but could require 100 times less energy in the future.##The outcome would look similar to that of the traditional photon lasers
but the physical mechanisms inside are very different#Kim says. The laser consists of an electron reservoir and a hole reservoir.
When a current is applied electrons and holes come together to form excitons in excited energy levels.
When a photon hits an exciton it forms a polariton and emits an identical photon.
The entire process is like a solar cell in reverse Kim says.##In a solar cell you use light to form excitons
and separate them into an electron and a hole electrically#she says.##We bring together an electron
and a hole electrically to emit light.##One benefit of the electrically driven polariton laser is it only needs to be attached to a power supply to emit photons allowing it to be integrated easily with existing semiconductor chips in the future.
Still too coolthe current polariton laser can run only at a chilly 4 degrees Kelvin (minus 452 degrees Fahrenheit)
and requires constant cooling by liquid helium to prevent the excitons inside the gallium arsenide semiconductors from being pulled apart by thermal energy.
The team hopes switching to a material that requires more energy to break apart excitons will allow them to build polariton lasers that work at room temperature an important step toward widespread use.#
#We re hoping we can replace conventional semiconductor lasers with these polariton lasers in the future#Kim says.#
#There are a lot of hurdles in the way but we aim to bring novel devices built on sound physical understanding for cost-effectiveness and efficient power consumption.#
#Stanford researchers are already using the polariton laser to develop quantum computers and quantum simulators. Kim believes similar lasers will be available to those outside the scientific community within the next five to 10 years.
Researchers conducted the work in collaboration with the National Institute of Informatics in Tokyo Japan and a team from the University of W##rzburg in Germany led by physicist Alfred Forchel.
The National Science Foundation the DARPA QUEST program the Japan Society for the Promotion of Science
#While only a proof-of-concept at this stage future research will demonstrate the device s capabilities as a low-cost way of analyzing individual proteins and gas molecules.
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