#Chemists one step closer to new generation of electric car battery Lithium sulphur (Li-S) batteries can theoretically power an electric car three times further than current lithium-ion batteries for the same weight at much
lower cost. Chemistry Professor Linda Nazar and her research team in the Faculty of science at the University of Waterloo have announced a breakthrough in Li-S battery technology based on chemical process discovered 170 years ago. his is a major step forward
and brings the Li-S battery one step closer to reality, said Nazar, who also holds the Canada Research Chair in Solid State Energy Materials
and is a Thomson Reutershighly Cited Researcher. Their discovery that nanosheets of manganese dioxide can maintain a rechargable sulphur cathode helps to overcome a primary hurdle to building a Li-S battery.
Their research appears in this week issue of Nature Communications. The fundamental mechanism at work is similar to the chemical process behind Wackenroder Solution discovered in 1845 during a golden age of German sulphur chemistry. ery few researchers study
or even teach sulphur chemistry anymore, said Nazar. t ironic we had to look so far back in the literature to understand something that may so radically change our future.
Nazar group is known best for their 2009 Nature Materials paper demonstrating the feasibility of a Li-S battery using nanomaterials.
In theory sulphur can provide a competitive cathode material to lithium cobalt oxide in current lithium-ion cells.
Sulphur as a battery material is extremely abundant, relatively light, and very cheap. Unfortunately, the sulphur cathode exhausts itself after only a few cycles
because the sulphur dissolves into the electrolyte solution as it reduced by incoming electrons to form polysulphides.
Nazar group originally thought that porous carbons or graphenes could stabilize the polysulphides by physically trapping them.
But in an unexpected twist, they discovered metal oxides could be the key. Their initial work on a metallic titanium oxide was published earlier in August innature Communications.
While the researchers found since then that nanosheets of manganese dioxide work even better than titanium oxides
their main goal in this paper was to clarify the mechanism at work. ou have to focus on a fundamental understanding of the phenomenon before you can develop new,
advanced materials, said Nazar. They found that the oxygenated surface of the ultrathin manganese dioxide nanosheet chemically recycles the sulphides in a two-step process involving a surface-bound intermediate, polythiosulfate.
The result is a high-performance cathode that can recharge more than 2000 cycles. Postdoctoral research associate Xiao Liang, the lead author,
and graduate students Connor Hart and Quan Pang also discovered that graphene oxide seems to work by a similar mechanism.
They are currently investigating other oxides to find the best sulphur retaining material. BASF International Scientific Network for Electrochemistry and Batteries funded the research.
The paper co-authors include Arnd Garsuch and Thomas Weiss of BASF n
#Vehicle body made from cotton hemp and wood Carbon and glass fibers reinforce synthetics so that they can be used for vehicle body construction.
But in this regard there is an abundance of potential found in natural fibers obtained from hemp cotton or wood.
If you combined bio-based textile and carbon fibers you can obtain extremely light yet very sturdy components. ightweightis an important buzzword in automotive engineering and just as important in the aerospace sector too.
Carmakers are increasingly counting on fiber reinforced synthetics. These fibers which are embedded into the synthetic matrix give the material its additional durability.
Exactly which material you choose to use depends on its eventual application. Thus primarily carbon fiber is used in Formula 1 racing.
However one drawback is its high price; even its processing can be tough. These are the reasons why carbon fiber-reinforced plastics (CFRPS) have still not yet found their path into wide-scale serial production so far to date.
Glass fibers on the other hand are priced certainly reasonably but heavy by comparison. But this may soon change thanks to some new research approaches by researchers at the Application Center for Wood Fiber Research HOFZET of the Fraunhofer Institute for Wood Research the Wilhelm-Klauditz-Institut WKI
in Braunschweig. Combining advantages eliminating disadvantagesthe scientists are relying on natural fibers of botanical origin. Variants derived from hemp flax cotton
and wood are about as affordable as glass fibers and moreover have a lower density than the pendants made of glass or carbon.
Another advantage: If you incinerate them at the end of their life cycle they produce additional energy without leaving residues.
Nevertheless their durability and stability don't reach that of carbon fibers. epending on the application we are therefore combining carbon with various bio-based textile fibersexplains Prof.
Dr.-Ing. Hans-Josef Endres head of the Application Center for Wood Fiber Research. The fibers typically exist as fabrics that are placed on each other accordingly
and are embedded by the plastic matrix. e use carbon fibers in those areas where the part undergoes intense mechanical stress;
in other areas it natural fibers. This way we can leverage the strengths of the respective fibers
and get rid of the disadvantages to a great extent. he outcome: the parts are cost-effective have a very high degree of durability possess excellent acoustic properties
and are substantially more ecological than pure carbon components. Typically you treat the surface of the natural fibers
and can be processed as well as possible into fabrics this is also referred to as izing the surface of the fiber
however if composite materials have to be processed. his is why from a materials engineering perspective we optimize the surfaces of the fiberssays Endres.
Specialized surface treatments or coatings are intended to ensure that the fibers can be combined and interact in the best possible way with the matrix or the plastic mass.
y ensuring that the fibers bond to the matrix optimally we can increase the durability of the materials by up to 50 percentendres explains in concrete terms.
and carbon fibers when it comes to use textile fibers for reinforcement the researchers are treading on virgin territory.
Because when it comes to recycling fiber composite materials are a proverbial ough nut to crack.
For instance how can expensive carbon fibers be extracted from the matrix and recovered? With the hybrid materials theye engineered the scientists are already considering in advance how these can be reprocessed
and present various textile bio-based hybrid materials (Hall 5. 2a). The researchers will also present fiber form-pressed components for the automotive industry there.
Fibers inside these parts are embedded into a thermoplastic matrix#plastic that is which can be shaped at ultra-high temperatures
or into a duroplastic synthetic matrix that once it has hardened fully can no longer be formed i
Software developed by Fraunhofer researchers will ensure an optimum use of the available wind energy at any time.
Running on heavy fuel oil freighters contribute to pollution. The International maritime organization (IMO) wants to reduce the environmental impact of ocean liners.
One of the measures: Starting from 2020, ships will only be allowed to use fuel containing maximum 0. 1 percent sulfur in their fuel in certain areas.
A new way of reducing fuel consumption, emissions and bunker expenses is being pursued by the Norwegian engineer Terje Lade,
For low-wind passages, in order to maneuver the ship on the open sea while also maintaining a constant speed,
Considering meteorological data the software for the new ship type uses a navigation algorithm to calculate a route with the optimum angle to the wind for maximum effect of the design. ith our weather routing module the best route can be calculated
After all, bunker expenses account for the largest part of the total costs in the shipping industry, says Laura Walther, researcher at CML in Hamburg.
such as aero-and hydrodynamic data as well as weather forecasts from the meteorological services, such as wind speed and wave height.
t angles close to headwind the wind generates a force in the ship direction. The ship is pulled forward.
By the end of January 2015, the software will be handed over to the company Lade AS.
are ships like car and truck carriers, big ferries, container ships and LNG CARRIERS. Terje Lade forecasts that the freighter will set sail as soon as 2019.
First, the ship model has to pass numerous tests in a marine research model tank also called a towing tank by experts.
#Solar chip monitors windows It happens all too often in the cold times of the year:
You open the window in the morning for fresh air and forget to shut it again.
A thermostat reports cold temperatures, and the heating is turned up full blast right out the window.
But open windows are a problem with more than just the heating or storms. A window tilted open,
for example, is a direct invitation to intruders. It would be desirable to have automated an system that notices open windows
and sends an alarm signal to the tenant. There are certainly home and building systems today that register the window status. As a rule
however, the sensors have to be attached by cable to the alarm center inside the home or building itself.
In other cases, battery-operated radio sensors are used. But changing batteries in structures that have several windows can lead to a considerable maintenance expense.
Researchers from the Fraunhofer Institute for Microelectronic Circuits and Systems IMS in Duisburg therefore developed a pragmatic alternative:
a radio sensor chip about the size of a fingernail that is mounted directly in the window.
The tiny sensor is coated with a solar cell and it supplies itself with power. Sensors differentiate between ball and crowbar At ten millimeters,
the chip is as narrow as a pane of insulating glass is thick. It is installed on the aluminum profile between the glass that maintains the distance between the panes.
Thanks to this window space, the solar cell obtains adequate light, even in the darkness of winter.
Integrated in the chip are magnet and acceleration sensors that register if the window is open just a crack or all the way.
The chip can send a signal via radio to the base station in the building
if a window has remained open for too long. The applications of the radio chip are diverse.
It can remind homeowners to ventilate regularly or warn if a window is still open
when they leave the Home in addition, it offers reliable protection from intruders even for closed windows.
Because the sensors can differentiate very precisely between various fluctuations for example, a ball that slams against the pane,
or an intruder crowbar that ratchets open the window frame. Within a tenth of a second, the system detects the disturbance
and sounds the alarm if there is any doubt. The IMS researchers around electrical engineer Dr. Gerd vom Bögel and physicist Dr. Andreas Goehlich have mastered just these two challenges:
First of all, they succeeded in depositing the solar cell directly onto the uneven surface of the chip.
Secondly, the chip consumes power so meagerly that energy from the miniscule solar cell spans the dark hours.
The microchips are coated with numerous conductor paths, its surface is made thereby very uneven. his is had why we to find a means of filling in and evening the surface,
like a street profile, prior to coating it with the solar cell, vom Bögel says. Currently IMS sensor prototypes can store enough power for up to 30 hours of darkness.
This is expected to lead to the emergence of a product over the next two years that can even bridge up to two weeks of darkness.
By keeping both processor and chip extremely small, the latter is extremely frugal. In addition, the researchers constructed switches that consume little energy,
and engineered very short radio protocols. e have extracted every possible microampere, says vom Bögel. Adding to the overall conservation of power is the fact that the sensor always switches to sleep mode.
Depending on the user preferences, the sensor can be set so that it wakes up every few minutes,
or even seconds, and takes a measurement. The Israeli firm SOLCHIP, which was asking for solar cells on chips at IMS around two years ago,
provided the impetus to developing the solar radio chip. Andreas Goehlich group of developers succeeded in integrating the solar cells on the surface of the chips.
Using these solar cells, SOLCHIP seeks to monitor the street traffic for example, or the climate conditions in vineyards. s you can see,
there are a lot of application areas, vom Bögel says. The production costs are so minimal because the application of the solar coating is connected directly to the production process of the chips. nly a handful of additional production steps are needed
so that manufacturing can also be accomplished in high quantities. h
#Defying textbook science study finds new role for proteins Open any introductory biology textbook and one of the first things youl learn is that our DNA spells out the instructions for making proteins,
tiny machines that do much of the work in our body cells. Results from a study published on Jan 2 in Science defy textbook science, showing for the first time that the building blocks of a protein,
called amino acids, can be assembled without blueprints DNA and an intermediate template called MESSENGER RNA (mrna). A team of researchers has observed a case in
which another protein specifies which amino acids are added. his surprising discovery reflects how incomplete our understanding of biology is,
says first author Peter Shen, Ph d, . a postdoctoral fellow in biochemistry at the University of Utah. ature is capable of more than we realize.
To put the new finding into perspective, it might help to think of the cell as a well-run factory.
Ribosomes are machines on a protein assembly line, linking together amino acids in an order specified by the genetic code.
When something goes wrong the ribosome can stall, and a quality control crew is summoned to the site.
To clean up the mess, the ribosome is disassembled, the blueprint is discarded, and the partly made protein is recycled.
Yet this study reveals a surprising role for one member of the quality control team, a protein conserved from yeast to man named Rqc2.
Before the incomplete protein is recycled, Rqc2 prompts the ribosomes to add just two amino acids (of a total of 20) alanine and threonine over and over,
and in any order. Think of an auto assembly line that keeps going despite having lost its instructions.
It picks up what it can and slaps it on: horn-wheel-wheel-horn-wheel-wheel-wheel-wheel-horn. n this case,
we have a protein playing a role normally filled by mrna, says Adam Frost, M d.,Ph d.,assistant professor at University of California, San francisco (UCSF) and adjunct professor of biochemistry at the University of Utah.
He shares senior authorship with Jonathan Weissman, Ph d.,a Howard hughes medical institute investigator at UCSF, and Onn Brandman, Ph d.,at Stanford university. love this story
because it blurs the lines of what we thought proteins could do. Like a half-made car with extra horns
and wheels tacked to one end, a truncated protein with an apparently random sequence of alanines and threonines looks strange,
and probably doesn work normally. But the nonsensical sequence likely serves specific purposes. The code could signal that the partial protein must be destroyed,
or it could be part of a test to see whether the ribosome is working properly.
either or both of these processes could be faulty in neurodegenerative diseases such as Alzheimer, Amyotrophic lateral sclerosis (ALS),
or Huntington. here are many interesting implications of this work and none of them would have been possible
It took extensive biochemical analysis to validate their hypothesis. New RNA sequencing techniques showed that the Rqc2/ribosome complex had the potential to add amino acids to stalled proteins because it also bound trnas
#A Battery That Last Twice as Long A Solidenergy startup has developed a lithium-ion battery that stores far more energy.
Energy storage lies in swapping the conventional electrode materialraphiteor a thin sheet of lithium-metal foil
The design consists of an ultra-thin metal anode made of thin lithium on copper
which enables ultra-high energy density and high-efficiency electrolyte which enables high current density at room temperature.
Solid Polymer Ionic Liquid (SPIL) electrolyte enables the ultra-thin lithium metal anode and improves the cell-level energy density by 50%compared to graphite anodes
and 30%compared to silicon-composite anodes. Batteries are safe nonflammable and nonvolatile and can operate at elevated temperatures.
It can be manufactured using existing Li-ion manufacturing facility leveraging mature infrastructure. The company says its prototype can be recharged 300 times while retaining 80%of its original storage capacityloser to
what you need in portable electronics a
#High efficiency concentrating solar cells move to the rooftop Ultra-high efficiency solar cells similar to those used in space may now be possible on your rooftop thanks to a new microscale solar concentration technology developed by an international team
of researchers. solar cells oncentrating photovoltaic (CPV) systems leverage the cost of high efficiency multi-junction solar cells by using inexpensive optics to concentrate sunlight onto them,
said Noel C. Giebink, assistant professor of electrical engineering, Penn State. urrent CPV systems are the size of billboards
and have to be pointed very accurately to track the sun throughout the day. But you can put a system like this on your roof,
which is where the majority of solar panels throughout the world are installed. Giebink notes that the falling cost of typical silicon solar cells is making them a smaller and smaller fraction of the overall cost of solar electricity,
which also includes oftcosts like permitting, wiring, installation and maintenance that have remained fixed over time.
Improving cell efficiency from about 20 percent for silicon toward greater than 40 percent with multi-junction CPV is important
because increasing the power generated by a given system reduces the overall cost of the electricity that it generates.
To enable CPV on rooftops the researchers combined miniaturized, gallium arsenide photovoltaic cells, 3d printed plastic lens arrays and a moveable focusing mechanism to reduce the size,
weight and cost of the CPV system and create something similar to a traditional solar panel that can be placed on the south-facing side of a building roof.
They report their results today (Feb 5) in Nature Communications. e partnered with colleagues at the University of Illinois
because they are experts at making small, very efficient multi-junction solar cells, said Giebink. hese cells are less than 1 square millimeter,
made in large, parallel batches and then an array of them is transferred onto a thin sheet of glass or plastic.
To focus sunlight on the array of cells, the researchers embedded them between a pair of 3d printed plastic lenslet arrays.
Each lenslet in the top array acts like a small magnifying glass and is matched to a lenslet in the bottom array that functions like a concave mirror.
With each tiny solar cell located in the focus of this duo, sunlight is intensified more than 200 times.
Because the focal point moves with the sun over the course of a day the middle solar cell sheet tracks by sliding laterally in between the lenslet array.
Previous attempts at such translation-based tracking have worked only for about two hours a day
because the focal point moves out of the plane of the solar cells, leading to loss of light and a drop in efficiency.
which allows small motors using a minimal amount of force for the mechanical tracking. he vision is that such a microtracking CPV panel could be placed on a roof in the same space as a traditional solar panel
Because the total panel thickness is only about a centimeter and 99 percent of it everything except the solar cells
and their wiring consists of acrylic plastic or Plexiglas, this system has the potential to be inexpensive to produce.
Giebink cautions however, that CPV systems are not suitable for all locations. PV only makes sense in areas with lots of direct sunlight,
The researchers tested their prototype concentrator panel outside over the course of a day in State College, Penn.
Even though the printed plastic lenses were not up to specification, they were able to demonstrate over 100 times solar concentration.
Others working on this project include Jared Price, graduate student Penn State; Xing Sheng, postdoctoral fellow; John A Rogers, professor of materials science and engineering, University of Illinois, Urbana Champaign;
and Bram M. Meulblok, technical representative, LUXEXCEL Group B. V.,The netherlands. Source: PS X
#One-atom-thin silicon transistors hold promise for super-fast computing Researchers at The University of Texas at Austin Cockrell School of engineering have created the first transistors made of silicene, the world thinnest silicon material.
Their research holds the promise of building dramatically faster, smaller and more efficient computer chips.
Made of a one-atom-thick layer of silicon atoms, silicene has outstanding electrical properties
but has until now proved difficult to produce and work with. Deji Akinwande, an assistant professor in the Cockrell School Department of Electrical and Computer engineering,
and his team, including lead researcher Li Tao, solved one of the major challenges surrounding silicene by demonstrating that it can be made into transistors emiconductor devices used to amplify and switch electronic signals and electrical power.
The first-of-their-kind devices developed by Akinwande and his teamrely on the thinnest of any semiconductor material, a longstanding dream of the chip industry,
and could pave the way for future generations of faster, energy-efficient computer chips. Their work was published this week in the journal Nature Nanotechnology.
Until a few years ago, human-made silicene was a purely theoretical material. Looking at carbon-based graphene
another atom-thick material with promise for chip development, researchers speculated that silicon atoms could be structured in a broadly similar way.
Akinwande, who also works on graphene transistors, sees value in silicene relationship to silicon, which chipmakers already know how to work with. part from introducing a new player in the playground of 2-D materials, silicene,
with its close chemical affinity to silicon, suggests an opportunity in the road map of the semiconductor industry,
Akinwande said. he major breakthrough here is the efficient low-temperature manufacturing and fabrication of silicene devices for the first time.
Despite its promise for commercial adaptation silicene has proved extremely difficult to create and work with because of its complexity
and instability when exposed to air. To work around these issues, Akinwande teamed with Alessandro Molle at the Institute for Microelectronics and Microsystems in Agrate Brianza, Italy,
to develop a new method for fabricating the silicene that reduces its exposure to air.
To start, the researchers let a hot vapor of silicon atoms condense onto a crystalline block of silver in a vacuum chamber.
They then formed a silicene sheet on a thin layer of silver and added a nanometer-thick layer of alumina on top.
Because of these protective layers the team could safely peel it of its base and transfer it silverside-up to an oxidized-silicon substrate.
They were then able to gently scrape some of the silver to leave behind two islands of metal as electrodes, with a strip of silicene between them.
In the near-term, Akinwande will continue to investigate new structures and methods for creating silicene,
which may lead to low energy, high-speed digital computer chips p
#Graphene displays clear prospects for flexible electronics Published in the scientific journal Nature Materials, University of Manchester and University of Sheffield researchers show that new 2d esigner materialscan be produced to create flexible, see-through and more efficient electronic devices.
The team, led by Nobel laureate Sir Kostya Novoselov, made the breakthrough by creating LEDS which were engineered on an atomic level.
The new research shows that graphene and related 2d materials could be utilised to create light emitting devices for the next-generation of mobile phones,
tablets and televisions to make them incredibly thin, flexible, durable and even semitransparent. The LED device was constructed by combining different 2d crystals
and emits light from across its whole surface. Being so thin, at only 10-40 atoms thick,
these new components can form the basis for the first generation of semitransparent smart devices.
One-atom thick graphene was isolated first and explored in 2004 at The University of Manchester.
Its potential uses are vast but one of the first areas in which products are likely to be seen is in electronics.
Other 2d materials, such as boron nitiride and molybdenum disulphide have since been discovered opening up vast new areas of research and applications possibilities.
By building heterostructures stacked layers of various 2d materials to create bespoke functionality and introducing quantum wells to control the movement of electrons,
new possibilities for graphene based optoelectronics have now been realised. Freddie Withers, Royal Academy of Engineering Research Fellow at The University of Manchester, who led the production of the devices,
said: s our new type of LED only consist of a few atomic layers of 2d materials they are flexible and transparent.
We envisage a new generation of optoelectronic devices to stem from this work, from simple transparent lighting and lasers and to more complex applications.
Explaining the creation of the LED device Sir Kostya Novoselov said: y preparing the heterostructures on elastic and transparent substrates,
we show that they can provide the basis for flexible and semitransparent electronics. he range of functionalities for the demonstrated heterostructures is expected to grow further on increasing the number of available 2d crystals
and improving their electronic quality. Prof Alexander Tartakovskii, from The University of Sheffield added: he novel LED structures are robust
and show no significant change in performance over many weeks of measurements. espite the early days in the raw materials manufacture,
the quantum efficiency (photons emitted per electron injected) is already comparable to organic LEDS. Source: University of Mancheste
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