LEDS use less energy emit less heat last longer and are less hazardous to the environment than traditional lighting.
Lower-efficiency incandescent and fluorescent bulbsâ##which use relatively more energy to produce lightâ##could become antiquated fixtures of the past. ur target is to get to 90 percent efficiency
or 300 lumens per wattsays Denbaars who also is a professor of electrical and computer engineering and co-director of the Solid State Lighting & Energy Center.
Current incandescent light bulbs by comparison are at roughly 5 percent efficiency and fluorescent lamps are a little more efficient at about 20 percent. e have demonstrated already up to 60 percent efficiency in lab demosdenbaars says.
#Photon detector is quantum leap from semiconductors A new superconducting detector array can measure the energy of individual photons.
MKIDS which operate at cryogenic temperatures (typically 0. 1 Kelvin) allow astronomers to determine the energy
#Wireless device grabs lost energy from Wi-fi Using inexpensive materials configured and tuned to capture microwave signals researchers have designed a power harvesting device with efficiency similar to that of modern solar panels.
The device wirelessly converts the microwave signal to direct current voltage capable of recharging a cell phone battery or other small electronic device according to a report appearing in Applied Physics Letters.
It operates on a similar principle to solar panels which convert light energy into electrical current. But this versatile energy harvester could be tuned to harvest the signal from other energy sources including satellite signals sound signals
or Wi-fi signals the researchers say. The key to the power harvester lies in its application of metamaterials engineered structures that can capture various forms of wave energy and tune them for useful applications.
Undergraduate engineering student Allen Hawkes working with graduate student Alexander Katko and lead investigator Steven Cummer professor of electrical and computer engineering designed an electrical circuit capable of harvesting microwaves.
They used a series of five fiberglass and copper energy conductors wired together on a circuit board to convert microwaves into 7. 3v of electrical energy.
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 with this design we were able to dramatically improve energy conversion to 37 percent which is comparable to
what is achieved in solar cells.?It s possible to use this design for a lot of different frequencies
and types of energy including vibration and sound energy harvestingkatko says. ntil now a lot of work with metamaterials has been theoretical.
We are showing that with a little work these materials can be useful for consumer applications
. or instance a metamaterial coating could be applied to the ceiling of a room to redirect and recover a Wi-fi signal that would
The design process used to create our metamaterial array takes these effects into account allowing the cells to work together. ith additional modifications the researchers say the power harvesting metamaterial could potentially be built into a cell phone allowing the phone to recharge wirelessly while not in use.
This feature could in principle allow people living in locations without ready access to a conventional power outlet to harvest energy from a nearby cell phone tower
. or example a series of power harvesting blocks could be assembled to capture the signal from a known set of satellites passing overhead the researchers explain.
The small amount of energy generated from these signals might power a sensor network in a remote location such as a mountaintop
Not so. nimals are a lot more clever with their mechanics than we often realizecowan says. y using just a little extra energy to control the opposing forces they create during those small shifts in direction animals seem to increase both stability
#How food can build better lithium batteries Cornell University rightoriginal Studyposted by Anne Ju-Cornell on October 29 2013a component of corn starch
and the yolk-shell structure of eggs can improve the durability and performance of lithium-sulfur battery cathodes report researchers.
Lithium-sulfur batteries are a promising alternative to today s lithium-ion batteries. here is currently a great need for high-energy long-life
and low-cost energy storage materials and lithium sulfur batteries are one of the most promising candidatessays Weidong Zhou a former postdoctoral researcher in Professor Hector Abruã a s lab at Cornell
and the Journal of the American Chemical Society. rom electric vehicles to solar and wind power applications for better lithium-based battery technologies are countless.?
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
and co-first author on the JACS publication. ut a lithium-sulfur battery is not a stable system as its capacity tends to fade over a short period of time. fter about 50 charge cycles the energy density of a lithium-sulfur
battery decreases rapidly due to a phenomenon called the polysulfide shuttling effect 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.
To combat this problem and stabilize the sulfur the researchers used amylopectin a polysaccharide that s a main component of corn starch. he corn starch can effectively wrap the graphene oxide-sulfide composite through the hydrogen bonding to confine the polysulfide among the carbon layerssays Hao Chen
and professor of chemistry and chemical biology. s an additive it greatly improves the cycling stability of the battery. n another approach to improving lithium-sulfur battery durability the researchers also report a new way
but the new method provides an internal void within the polymer shell called a olk-shellstructure. hen the lithium-sulfur battery was discharged fully the volume of the sulfur expanded dramatically to 200 percent.
The Department of energy and the Energy Materials Center at Cornell an Energy Frontier Research center funded by the US DOE funded the papers.
and requires no batteries it could allow the manufacture of small lightweight and inexpensive location and identification tags for animals infrastructure (pipelines conduits for example)
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)
In fact it should be possible to construct these power cells out of the excess silicon that exists in the current generation of solar cells sensors mobile phones
. 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.
and operate for a few million cycles instead of a few thousand cycles like batteries. These properties have allowed commercial supercapacitors
which are made out of activated carbon to capture a few niche markets such as storing energy captured by regenerative braking systems on buses
and electric vehicles and to provide the bursts of power required to adjust of the blades of giant wind turbines to changing wind conditions.
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.
And when they used it to make supercapacitors they found that the graphene coating improved energy densities by over two orders of magnitude compared to those made from uncoated porous silicon and significantly better than commercial supercapacitors.
Pint and his group argue that this approach isn t limited to graphene. he ability to engineer surfaces with atomically thin layers of materials combined with the control achieved in designing porous materials opens opportunities for a number of different applications beyond energy storagehe
says. espite the excellent device performance we achieved our goal wasn t to create devices with record performancesays Pint. t was to develop a road map for integrated energy storage.
since it is very expensive and wasteful to produce thin silicon wafers. int s group is currently using this approach to develop energy storage that can be formed in the excess materials or on the unused backsides of solar cells and sensors.
The supercapacitors would store excess electricity that the cells generate at midday and release it when the demand peaks in the afternoon. ll the things that define us in a modern environment require electricitysays Pint. he more that we can integrate power storage into existing materials
A new iller materialcan help put an end to dropped calls by making cell phones that tune to different frequencies without wasting battery power.
what people have been using for decadessays Darrell Schlom professor of industrial chemistry at Cornell University who led the international research team. hat we have discovered is the world's lowest-loss tunable dielectric. ossrefers to wasted energy
which drains cell phone batteries. The new type of tunable dielectric could greatly improve the performance of microwave circuit capacitors found in every cell phone
#Ceramic converter tackles solar cell problem Stanford university rightoriginal Studyposted by Mark Shwartz-Stanford on October 21 2013coating a solar cell component in ceramics makes it more heat resistant
which can be absorbed by solar cells to make electricity a technology known as thermophotovoltaics. Unlike earlier prototypes that fell apart before temperatures reached 2200 degrees Fahrenheit (1200 degrees Celsius) the new thermal emitter remains stable at temperatures as high as 2500 F
A typical solar cell has a silicon semiconductor that absorbs sunlight directly and converts it into electrical energy.
But silicon semiconductors only respond to infrared light. 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
because they throw away the majority of the sun s energy. hermophotovoltaic devices are designed to overcome that limitation.
Instead of sending sunlight directly to the solar cell thermophotovoltaic systems have an intermediate component that consists of two parts:
which is beamed then to the solar cell. ssentially we tailor the light to shorter wavelengths that are ideal for driving a solar cellfan explains. hat raises the theoretical efficiency of the cell to 80 percent
which is quite remarkable. o far thermophotovoltaic systems have achieved only an efficiency level of about 8 percent Braun notes.
which is made typically of tungsten##an abundant material also used in conventional light bulbs. ur thermal emitters have a complex three-dimensional nanostructure that has to withstand temperatures above 1800 F 1000 C to be practicalbraun says n fact the hotter
and his colleagues at Stanford who confirmed that devices were still capable of producing infrared light waves that are ideal for running solar cells. hese results are unprecedentedsays former Illinois graduate student Kevin Arpin the lead author of the study. e demonstrated for the first time that ceramics
could help advance thermophotovoltaics as well other areas of research including energy harvesting from waste heat high-temperature catalysis
and electrochemical energy storage. raun and Fan plan to test other ceramic-type materials and determine if the experimental thermal emitters can deliver infrared light to a working solar cell. e ve demonstrated that the tailoring of optical properties at high temperatures is possiblebraun says. afnium
and tungsten are abundant low-cost materials and the process used to make these heat-resistant emitters
is established well. opefully these results will motivate the thermophotovoltaics community to take another look at ceramics
and Energy project and the Department of energy s Light-Material Interactions in Energy conversion Center supported the work along with the National Science Foundation and the Research Triangle Solar fuels Institute.
The framework could also be useful to the energy industry which typically relies on seismic waves to search for underwater oil and natural gas.
if you hit that same stop sign at 40 miles an hourgregg says. hereâ#a lot more energy that will be released. he Iceland formations some over 2 meters tall display telltale features that hint at how they were created.
which may make it useful for protecting solar cells from the elements Lou says. ssentially this can be a very useful structural material coating
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
Then any additional acceleration increases their energy but not their speed; this is the challenging part.
Infrared laser light shining on the pattern generates electrical fields that interact with the electrons in the channel to boost their energy.
and electronic devices when it is used as a reference. good tuning fork controls the release of its acoustical energy ringing just one pitch at a particular sound frequency for a long timeâ##a sustaining property called the quality factor.
Frequency instability stems from energy surges within the optical resonatorâ##which are unavoidable due to the laws of thermodynamics.
Because the new resonator has a longer path the energy changes are diluted so the power surges are dampenedâ##greatly improving the consistency
In combination with the resonator a special guide for the light was used losing 100 times less energy than the average chip-based device.
CNTS are long chains of carbon atoms that are extremely efficient at conducting and controlling electricity.
They are so thinâ##thousands of CNTS could fit side by side in a human hairâ##that it takes very little energy to switch them off according to Wong a co-author of the paper. hink of it as stepping on a garden hosewong explains. he thinner the hose the easier it is to shut off the flow. n theory this combination
Depending on how the CNTS grow a fraction of these carbon nanotubes can end up behaving like metallic wires that always conduct electricity instead of acting like semiconductors that can be switched off.
Then they pumped the semiconductor circuit full of electricity. All of that electricity concentrated in the metallic nanotubes
which grew so hot that they burned up and literally vaporized into tiny puffs of carbon dioxide.
Researchers say the discovery could one day lead to bigger harvests of biomass for renewable energy.
and thus better harvest bioenergy. ong and Daniel Cosgrove professor and chair in biology at Penn State are the lead authors.
#Colonies of wired microbes turn sewage into electricity Stanford university rightoriginal Studyposted by Tom Abate-Stanford on September 19 2013a new way to generate electricity from sewage uses naturally occurring ired microbesas mini power plants
to produce electricity as they digest plant and animal waste. Scientists hope the icrobial batterycan be used in places such as sewage treatment plants
At the moment however the laboratory prototype is about the size of A d-cell battery and looks like a chemistry experiment with two electrodes one positive the other negative plunged into a bottle of wastewater.
and produce electricity that is captured by the battery s positive electrode. e call it fishing for electronssays Craig Criddle a professor in the department of civil and environmental engineering at Stanford university.
but tapping this energy efficiently has proven challenging. What is new about the microbial battery is a simple yet efficient design that puts these exoelectrogenic bacteria to work.
As reported in the Proceedings of the National Academy of Sciences at the battery s negative electrode colonies of wired microbes cling to carbon filaments that serve as efficient electrical conductors.
Using a scanning electron microscope the Stanford team captured images of these microbes attaching milky tendrils to the carbon filaments. ou can see that the microbes make nanowires to dump off their excess electronscriddle says.
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.
That is roughly the same efficiency at which the best commercially available solar cells convert sunlight into electricity.
Of course there is far less energy potential in wastewater. Even so the microbial battery is worth pursuing because it could offset some of the electricity now used to treat wastewater.
That use currently accounts for about 3 percent of the total electrical load in developed nations.
Most of this electricity goes toward pumping air into wastewater at conventional treatment plants where ordinary bacteria use oxygen in the course of digestion just like humans and other animals.
Looking ahead the engineers say their biggest challenge will be finding a cheap but efficient material for the positive node. e demonstrated the principle using silver oxide
which suggests that the general fabrication technique the researchers developed could be used to produce lightweight mechanically robust small-scale components such as batteries interfaces catalysts
or gel-type electrolytes, which have been limited to low-temperature operation of electrochemical devices, says Arava Leela Mohana Reddy,
lead author and a former research scientist at Rice Unversity who is now an assistant professor at Wayne State university in Detroit. e found that a clay-based membrane electrolyte is a game-changing breakthrough that overcomes one of the key limitations of high
-temperature operation of electrochemical energy devices, Reddy says. y allowing safe operation over a wide range of temperatures without compromising on high energy,
and discharge energy in a burst and rechargeable batteries that charge slowly but release energy on demand over time.
The ideal supercapacitor would charge quickly, store energy, and release it as needed. esearchers have been trying for years to make energy storage devices like batteries and supercapacitors that work reliably in high-temperature environments,
but this has been given challenging the traditional materials used to build these devices, explains Pulickel Ajayan,
In particular, researchers have struggled to find an electrolyte, 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.
The separator keeps the electrolyte on the anode and cathode sides of a traditional battery apart
while allowing ions to pass through). ur innovation has been to identify an unconventional electrolyte/separator system that remains stable at high temperatures,
Ajayan says. The researchers solved both problems at once. First, they investigated using room-temperature ionic liquids (RTILS) developed in 2009 by European and Australian researchers.
Both energy and power density improved by two orders of magnitude as the operating temperature increased from room temperature to 200 degrees Celsius, the researchers found.
The Advanced Energy Consortium supported the research o
#Could this gene make leafy greens last longer? Scientists have identified the process in plants that controls how quickly leaves die which may lead to lettuce that stays fresh in the fridge a little longer.
because more energy is available or because distractions and new inputs are fewer says corresponding author Yuka Sasaki a research associate professor in the department of cognitive linguistic & psychological sciences.#
#In an era of light-weighting for energy and emissions reductions there is a great demand for magnesium alloys in everything from portable electronics to air
for widespread use in renewable energy storage portable electronics and electric vehicles. Supercapacitors are made generally of highly porous carbon impregnated with a liquid electrolyte to transport the electrical charge.
Known for their almost indefinite lifespan 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.
and his team created a supercapacitor with energy density of 60 watt-hours per liter#comparable to lead-acid batteries and around 12 times higher than commercially available supercapacitors.#
when graphite is broken down into layers one atom thick is very strong chemically stable and an excellent conductor of electricity.
They used liquid electrolytes#generally the conductor in traditional supercapacitors#to control the spacing between graphene sheets on the subnanometer scale.
In this way the liquid electrolyte played a dual role: maintaining the minute space between the graphene sheets and conducting electricity.
Unlike in traditional#hard#porous carbon where space is wasted with unnecessarily large pores density is maximized without compromising porosity in Li s electrode.
because the organisms do not waste metabolic energy producing unneeded proteins. The team which includes researchers from Washington University School of medicine plans to explore
##Solar steam kills germs while off the grid RICE (US) A new sterilization system uses nanomaterials to convert 80 percent of the energy in sunlight into heat,
and sterilization are enormous obstacles without reliable electricity, says Naomi Halas, director of the Laboratory for Nanophotonics (LANP) at Rice university. olar steam efficiency at converting sunlight directly into steam opens up new possibilities for off-grid sterilization that simply aren available today In a previous study last year,
Halas and colleagues showed that olar steamwas so effective at direct conversion of solar energy into heat that it could even produce steam from ice water. t makes steam directly from sunlight,
Photovoltaic solar panels, by comparison, typically have an overall energy efficiency of around 15 percent. When used in the autoclaves in the tests,
Commercial applications in small electronic devices solar cells batteries and even medical devices are just around the corner.
The energy barrier required for a sheet to cut the membrane was simply too high even
#Graphene ribbons improve lithium ion batteries Anodes for lithium ion batteries built with ribbons of graphene perform better, tests show.
After 50 charge-discharge cycles, the proof-of-concept units retained a capacity that was still more than double that of the graphite currently used for LI battery anodes.
One area ripe for improvement is the humble battery. In an increasingly mobile world battery capacity is becoming a bottleneck that generally limits devices to less than a day worth of use.
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
and encased it in a button-style battery. GNRS are a single atom thick and thousands of times longer than they are wide.
GNRS could also help overcome a prime difficulty with LI battery development. Lithium ions tend to expand the material they inhabit,
GNRS take a different approach by giving batteries a degree of flexibility, Tour says. raphene nanoribbons make a terrific framework that keeps the tin oxide nanoparticles dispersed
Lin says the lab plans to build batteries with other metallic nanoparticles to test their cycling and storage capacities.
The embedded fossils are likely planktonic autotrophs free-floating tiny ocean organisms that produce energy from their environment.
because they used carbon dioxide to create energy and incorporated the carbon into themselves. During this process the organisms selectively incorporate more carbon 12 than carbon 13 from the available carbon producing a signature of biological origin.
Successful tests were performed using live bed bugs and termites in Rafailovich#s lab with the assistance of Ying Liu a scientist with the Advanced Energy Research and Technology Center and graduate students Shan He and Linxi Zhang.
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.
if an electron in an upper energy level was exposed to a photon with proper energy the electron would instantly fall down
A laser keeps this process going by continually providing energy for electrons to move into higher energy levels.
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
and an unlimited number of them can inhabit any given energy level. Using bosons in lasers has been a scientific goal for decades
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
and holes come together to form excitons in excited energy levels. When a photon hits an exciton it forms a polariton
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 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.#
but we aim to bring novel devices built on sound physical understanding for cost-effectiveness and efficient power consumption.#
Because metals will naturally convert some energy from infrared light into heat researchers can connect the amount the material expands to the amount of infrared light hitting it.#
#Ambiq Micro has made a chip that consumes 10 times less energy Ambiq Micro, a semiconductor company in Austin,
which can lower the power consumption of the tiny chips used inside wearable devices by as much as 10 times in wake mode
this means a battery life for a smart watch or activity tracker that could last for weeks or months longer than the current standard.
That means it uses much less energy overall. Ambiq has built out this technology on about $30 million in funding.
Salas also says that for customers of Ambiq the change in power consumption mean manufacturers can advertise longer battery life,
or they could use smaller batteries and then design smaller enclosures for their electronics. As a woman who finds almost all of the smart watches on the market today to be too large
I love to see a slightly more delicate form factor using a smaller battery and more power-efficient chip h
Overtext Web Module V3.0 Alpha
Copyright Semantic-Knowledge, 1994-2011