All graphene computer chips designed in a research paper
For now, UCSB’s design is just that — a computer model that should
technically work, but which hasn’t been built yet. In theory, though,
with the worldwide efforts to improve high-quality graphene production
and patterning, we should be able to build an all-graphene IC in the
next few years. Even then, though, it will still take a long time to go
from laboratory prototype to full-scale commercial production — perhaps a
decade or more. For the time being, the higher electron mobility of
III-V semiconductors compared to silicon should provide a stopgap
solution for the continuing miniaturization and ultra-low-power
requirements of modern computing. When graphene ICs do finally take off,
though, we have terahertz switching speeds and transistor densities in
the tens-of-billions to look forward to.
Proposal for all-graphene monolithic logic circuits
ABSTRACT
Since the very inception of integrated circuits, dissimilar materials
have been used for fabricating devices and interconnects. Typically,
semiconductors are used for devices and metals are used for
interconnecting them. This, however, leads to a “contact resistance”
between them that degrades device and circuit performance, especially
for nanoscale technologies. This letter introduces and explores an
“all-graphene” device-interconnect co-design scheme, where a single
2-dimensional sheet of monolayer graphene is proposed to be
monolithically patterned to form both active devices (graphene
nanoribbon tunnel-field-effect-transistors) as well as interconnects in a
seamless manner. Thereby, the use of external contacts is alleviated,
resulting in substantial reduction in contact parasitics. Calculations
based on tight-binding theory and Non-Equilibrium Green's Function
(NEGF) formalism solved self-consistently with the Poisson's equation
are used to analyze the intricate properties of the proposed structure.
This constitutes the first NEGF simulation based demonstration that
devices and interconnects can be built using the “same starting
material” – graphene. Moreover, it is also shown that all-graphene
circuits can surpass the static performances of the 22 nm complementary
metal-oxide-semiconductor devices, including minimum operable supply
voltage, static noise margin, and power consumption.
Friday, October 25, 2013
Tuesday, October 8, 2013
Wednesday, October 2, 2013
KTH | Battery low? Give your mobile some water
KTH | Battery low? Give your mobile some water
Based on micro fuel cell technology developed at KTH Royal Institute of Technology in Stockholm, the MyFC PowerTrekk uses ordinary water to extend battery life for devices of up to 3 watts.
Anders Lundblad, KTH researcher and founder of MyFC, says that the device can be powered by fresh or seawater. The water need not be completely clean.
“Our invention has great potential to accelerate social development in emerging markets,” Lundblad says. “There are large areas that lack electricity, while mobile phones fulfil more and more vital functions, such as access to weather information or electronic payment.”
A USB connector attaches the compact PowerTrekk charger to the device. When plain water is poured onto a small recyclable metal disc inside the unit, hydrogen gas is released and combines with oxygen to convert chemical energy into electrical energy. The resulting charge is enough to power an iPhone to between 25 and 100 per cent of its battery capacity.
Lundblad has done research on micro fuel cells and small flat Proton Exchange Membrane (PEM) fuel cells for more than 15 years at the Department of Applied Electrochemistry at KTH. He says the business vision behind MyFC is to commercialise fuel cell technology and contribute to the development of environmental technology.
He says the charger is the first step toward building fuel cells in laptops.
“The launch of our charger is a strategic move to gain wide acceptance of fuel cells throughout society,” he says. “Our chargers may be considered expensive now; but in the longer term, as they reach a mass market, they would go down in price.”
Fuel cells can already be found in electric cars, trucks and buses, and
backup electrical power supply systems for hospitals and cogeneration
plants. The process by which fuel cells generate electricity is
considered to be safe and environmentally-friendly, and the only
by-product is water vapour. The fuel cell system is passive and has no
fans or pumps.
Lundblad says that fuel cell chargers are faster and more reliable than solar chargers. The main target groups for MyFC PowerTrekk are those who travel or live in remote areas of the world, outdoor enthusiasts and aid workers, he says.
The charger is both a fuel cell and a portable battery, providing a direct power source as well as a storage buffer for the fuel.
MyFC plans to open an online shop for its MyFC PowerTrekk product. The company has already sold the technology to users in China, Japan, the U.S. and much of Europe.
For more information contact Anders Lundblad on anders.lundblad @ myfc.se.
Katarina Ahlfort
Based on micro fuel cell technology developed at KTH Royal Institute of Technology in Stockholm, the MyFC PowerTrekk uses ordinary water to extend battery life for devices of up to 3 watts.
Anders Lundblad, KTH researcher and founder of MyFC, says that the device can be powered by fresh or seawater. The water need not be completely clean.
“Our invention has great potential to accelerate social development in emerging markets,” Lundblad says. “There are large areas that lack electricity, while mobile phones fulfil more and more vital functions, such as access to weather information or electronic payment.”
A USB connector attaches the compact PowerTrekk charger to the device. When plain water is poured onto a small recyclable metal disc inside the unit, hydrogen gas is released and combines with oxygen to convert chemical energy into electrical energy. The resulting charge is enough to power an iPhone to between 25 and 100 per cent of its battery capacity.
Lundblad has done research on micro fuel cells and small flat Proton Exchange Membrane (PEM) fuel cells for more than 15 years at the Department of Applied Electrochemistry at KTH. He says the business vision behind MyFC is to commercialise fuel cell technology and contribute to the development of environmental technology.
He says the charger is the first step toward building fuel cells in laptops.
“The launch of our charger is a strategic move to gain wide acceptance of fuel cells throughout society,” he says. “Our chargers may be considered expensive now; but in the longer term, as they reach a mass market, they would go down in price.”
Lundblad says that fuel cell chargers are faster and more reliable than solar chargers. The main target groups for MyFC PowerTrekk are those who travel or live in remote areas of the world, outdoor enthusiasts and aid workers, he says.
The charger is both a fuel cell and a portable battery, providing a direct power source as well as a storage buffer for the fuel.
MyFC plans to open an online shop for its MyFC PowerTrekk product. The company has already sold the technology to users in China, Japan, the U.S. and much of Europe.
For more information contact Anders Lundblad on anders.lundblad @ myfc.se.
Katarina Ahlfort
Japanese start-up plans hydrogen fuel cell for 2014 - Batteries / fuel cells, Components, Rohm, Aquafairy, CEATEC - Computerworld
Japanese start-up plans hydrogen fuel cell for 2014 - Batteries / fuel cells, Components, Rohm, Aquafairy, CEATEC - Computerworld
A Japanese start-up says it has finessed a
technology that could finally make consumer-grade fuel cells a reality.
If successful, the company, Aquafairy, would create a business where
many much larger companies have failed.
Prototypes
of the company's hydrogen fuel cell technology are on show this week at
the Ceatec exhibition in Japan where the company's president, Mike
Aizawa, said he hopes the first products will be on sale next year.
The
promise of fuel cells is attractive: instantly available electricity
from a safe, disposable fuel cartridge. They are typically seen as a way
to provide electricity where there is no power grid, when electricity
supply has failed or, in a portable package, for on-the-go charging of
gadgets such as smartphones or tablets.
Japan's
major electronics companies went through a period of several years
beginning around 2005 when they showed prototype fuel cells, but none of
them ever managed to reach the market and much of that research appears
to have ended.
"They all failed because they
used Methanol," said Aizawa in an interview with the IDG News Service.
"They couldn't figure out a way to do it efficiently. If I had thought
they would have succeeded, I never would have started my company."
Aquafairy
was established in mid-2006 and has been developing a fuel cell based
on hydrogen. Typically an extremely reactive fuel, the company has
developed a treatment that turns it into a sold form that's safe to
handle but is still useful as a fuel, said Aizawa.
At Ceatec, the company has three working prototype fuel cells on show.
A
pocket-size portable model, designed to fully charge a smartphone,
appeared to be attracting the most interest. Producing 2.5 watts of
power, it's a little lighter than a smartphone at 89 grams and measures
about the same size. Through USB, it can charge most portable
electronics gadgets.
A second charger is already
in field trials in Japan and can deliver 200 watts of power. Weighing 7
kilograms and a little smaller than a conventional car battery, it's
powered by a canister containing solid hydrogen that looks similar to
the small butane canisters used in camping stoves.
Developed
with Japan's New Energy and Industrial Technology Development
Organization (NEDO), it has a couple of USB outputs and two conventional
AC outputs. This charger is being eyed for use after disasters, like
2011's earthquake and tsunami that hit Japan.
The
final charger is a long-life type designed for use in remote areas,
such as mountains and forests. It provides just half a watt, but can do
so for half a year meaning trips to replace batteries on things like
scientific measuring equipment don't need to be made frequently.
Aquafairy
is working with Japan's Rohm on the control circuitry for the chargers
and to bring the products to market, but says it is also looking for
partnerships with other companies and organizations.
Aizawa didn't provide a cost for the technology, but said he knows he has to deliver it at a consumer-friendly price.
"That's my job for the next year," he said.
Martyn Williams covers mobile telecoms, Silicon Valley and general technology breaking news for The IDG News Service. Follow Martyn on Twitter at @martyn_williams. Martyn's e-mail address is martyn_williams@idg.com
Monday, September 30, 2013
China's Synthetic Natural Gas Plants Could Accelerate Climate Change - Businessweek
China's Synthetic Natural Gas Plants Could Accelerate Climate Change - Businessweek
Unfortunately, one scheme to limit coal burning by converting China’s plentiful coal supplies into synthetic natural gas (SNG) presents a host of other ecological worries. To date, China’s government has approved construction of nine large SNG plants in northern and western China, which are projected to generate 37 billion cubic meters of gas each year when completed. At least 30 more proposed plants are awaiting approval.
None of these planned plants are located near large Chinese cities, so the emissions generated in producing the gas will not hang directly over metropolises. But that doesn’t mean the coal-to-gas conversion process is clean. According to a new study (PDF) in Nature Climate Change, the entire life cycle of harvesting coal and turning it into gas produces from 36 percent to 82 percent more total greenhouse gas emissions than burning coal directly—depending on whether the gas is used to generate electricity or power vehicles.
While the most-polluting stages of energy generation could be moved farther from China’s population centers—perhaps allowing for more brighter, cleaner days in Beijing—the net effect could be to accelerate global climate change, argue the study’s authors, Chi-Jen Yang and Robert Jackson of the Nicholas School of the Environment at Duke University.
Moreover, the scarcely populated hinterland regions earmarked for the SNG plants are dry, while converting coal to gas is a water-intensive process. “The water consumption for [synthetic natural gas] production could worsen water shortages in areas already under significant water stress,” write Yang and Jackson. “Overall, the large-scale deployment of SNG will dramatically increase water use, [greenhouse gas] emissions, and additional air and water pollution.”
When it comes to tackling China’s many environmental challenges, it’s, alas, much easier to point out flaws in current government approaches than to find sustainable solutions.
Unfortunately, one scheme to limit coal burning by converting China’s plentiful coal supplies into synthetic natural gas (SNG) presents a host of other ecological worries. To date, China’s government has approved construction of nine large SNG plants in northern and western China, which are projected to generate 37 billion cubic meters of gas each year when completed. At least 30 more proposed plants are awaiting approval.
None of these planned plants are located near large Chinese cities, so the emissions generated in producing the gas will not hang directly over metropolises. But that doesn’t mean the coal-to-gas conversion process is clean. According to a new study (PDF) in Nature Climate Change, the entire life cycle of harvesting coal and turning it into gas produces from 36 percent to 82 percent more total greenhouse gas emissions than burning coal directly—depending on whether the gas is used to generate electricity or power vehicles.
While the most-polluting stages of energy generation could be moved farther from China’s population centers—perhaps allowing for more brighter, cleaner days in Beijing—the net effect could be to accelerate global climate change, argue the study’s authors, Chi-Jen Yang and Robert Jackson of the Nicholas School of the Environment at Duke University.
Moreover, the scarcely populated hinterland regions earmarked for the SNG plants are dry, while converting coal to gas is a water-intensive process. “The water consumption for [synthetic natural gas] production could worsen water shortages in areas already under significant water stress,” write Yang and Jackson. “Overall, the large-scale deployment of SNG will dramatically increase water use, [greenhouse gas] emissions, and additional air and water pollution.”
When it comes to tackling China’s many environmental challenges, it’s, alas, much easier to point out flaws in current government approaches than to find sustainable solutions.
Tuesday, September 24, 2013
New Wind Contract Cheaper Than Coal, Nuclear
Daily Kos: BFD: New Wind Contract Cheaper Than Coal, Nuclear
The utilities — National Grid, Northeast Utilities, and Unitil Corp. — would buy 565 megawatts of electricity from six wind farms in Maine and New Hampshire, enough to power an estimated 170,000 homes. The projects, in various stages of permitting or development, are expected to begin operations between 2014 and 2016.
John Howat, senior energy analyst at the Boston-based National Consumer Law Center, said he needed to review the details before he could provide a thorough assessment of the contracts. But his initial reaction to the price — on average, less than 8 cents per kilowatt hour? “Wow.”
For a comparison, in the same time frame gas is projected to cost 7 cents/KWH, coal 10 cents/KWH and nuclear 11 cents/KWH. A dollar a month may not seem like a lot. But if wind is cheaper than coal & nuclear, why would you ever build a new coal-fired or nuclear power plant? And that's not even starting to account for all the climate change, public health and wildlife benefits that come with switching from coal to wind. When the cost of pollution is factored in, both wind and solar power blow the doors off of coal and are competitive with gas.
Why should we go all-in on wind when gas is projected to be slightly cheaper? Because New England is already dangerously dependent on gas, leaving us vulnerable to price spikes like we saw last winter. And since gas plants can fire up much faster than coal plants, gas and wind actually go very well together. (No, that was not a fart joke. Let's keep moving.)
The utilities — National Grid, Northeast Utilities, and Unitil Corp. — would buy 565 megawatts of electricity from six wind farms in Maine and New Hampshire, enough to power an estimated 170,000 homes. The projects, in various stages of permitting or development, are expected to begin operations between 2014 and 2016.
John Howat, senior energy analyst at the Boston-based National Consumer Law Center, said he needed to review the details before he could provide a thorough assessment of the contracts. But his initial reaction to the price — on average, less than 8 cents per kilowatt hour? “Wow.”
For a comparison, in the same time frame gas is projected to cost 7 cents/KWH, coal 10 cents/KWH and nuclear 11 cents/KWH. A dollar a month may not seem like a lot. But if wind is cheaper than coal & nuclear, why would you ever build a new coal-fired or nuclear power plant? And that's not even starting to account for all the climate change, public health and wildlife benefits that come with switching from coal to wind. When the cost of pollution is factored in, both wind and solar power blow the doors off of coal and are competitive with gas.
Why should we go all-in on wind when gas is projected to be slightly cheaper? Because New England is already dangerously dependent on gas, leaving us vulnerable to price spikes like we saw last winter. And since gas plants can fire up much faster than coal plants, gas and wind actually go very well together. (No, that was not a fart joke. Let's keep moving.)
Monday, September 23, 2013
under ground housing by Mike Oehler
under ground housing by Mike Oehler
.
Design
The PSP construction process is simple and easily understood. But the concept of living under the ground is extremely alien to most people who haven’t been exposed to Mike Oehler’s design concepts. In addition, proper design is the single most important key to the success of an underground dwelling, in terms of light, ventilation, and most importantly, drainage.
So it’s not surprising that Mike spends most of his time and effort, in his book as well as videos, on design.
Conventional thinking (if that can be applied to something as radical as U housing) most often involves digging a hole into a hillside and plopping a structure there. A bank of windows faces downhill, while the uphill side is a solid blank wall. More often than not, if the house is on a south slope, the roof is pitched back into the hill, so drainage from the roof runs into drainage from the hillside. Leaks are almost inevitable. There is little or no air flow, the back of the house is dark and damp, and the view is limited.
Mike calls this the first-thought design. His thinking has taken him far beyond that.
The five approved methods of design
In his videos he stresses designs with views – and light and ventilation – in all four directions, and he urges viewers to try it themselves (with accompanying worksheets). Although some of the ideas are revolutionary, he simply calls them the Five Approved Methods of Design.
They are: the uphill patio; the off-set room; clerestories; the Royer foyer; and gables.
The uphill patio
The uphill patio is as useful as it is clever. It is basically a terraced garden area, with its bottom at any desired height from the floor of the house, and its top blending into the adjacent ground level. It not only solves problems of drainage and lateral thrust (the pressure of the earth on buried walls), but it can function as an emergency exit or a second entrance. It can also serve as a built-in greenhouse.
Naturally, it admits light and air, even from the uphill side of the house which would otherwise be a dark blank wall. This not only reduces kerosene or electric bills but results in more balanced lighting.
The view is up to the garden design interests and abilities of the owner, of course. Japanese courtyard gardens, which are world-renowned works of art, are offered as an example of the possibilities.
And finally, the uphill patio offers a controlled view. It’s determined by the depth of the patio and the resultant trajectory of sight. No matter what anyone builds nearby, you won’t have to look at it if you don’t want to. (If the neighbor builds a 20-story high-rise one foot from your property line, put a greenhouse covering on the patio.) And no one can see into it (or your home) unless they’re standing right on top of it.
The offset room
The basic U house design is a square or rectangular room. The simple expedient of adding a second room, and offsetting it to protrude into the uphill patio, provides the opportunity to install a section of windows which face an entirely different direction. This offers even more advantages of views, light, and ventilation. Elevating the offset room results in even more design possibilities.
The Royer foyer
The Royer foyer is a design invention which allows us to have a good view down a hill without rechanneling the flow of drainage or interrupting the purity of design of a shed roof. The Royer foyer sneaks into the hillside rather than protruding from it. It makes possible a downhill view from windows that are all but concealed from neighbors.
The foyer (named after the helper friend who came up with the idea) is a pie-shaped excavation away from the house on the side wall (not the downhill wall) of a downhill corner. It has many advantages and attributes, all discussed and illustrated in the book.
Clerestories and gables
Clerestories and gables are nothing new, but they can be valuable contributions to underground housing. As might be expected, however, there are details to consider when incorporating them into an underground PSP house… where the three primary demands are drainage, drainage, and drainage. Details are provided in the book.
Also included are discussions of earthen floors, built-in root cellars, earth coolers, a barbecue window and bachelor bar, plumbing and wiring considerations, engineering rules of thumb, scrounging materials… and everything else you’ll need to know to build your own pleasant, comfortable and affordable underground home.
Construction of an emergency shelter
You really need the book, and perhaps the videos, to get a good grasp of the construction method and, more importantly, design considerations. But many readers who don’t consider themselves candidates for building an underground house – or even a root cellar or tornado shelter – might appreciate knowing how it’s done, just in case. Mike Oehler covers this aspect in his latest book, "The Hippie’s Guide to Y2K" (see review in 83/3:110). He calls it the Pit House. It’s as simple as this:
Dig a hole. Cover it with logs. Cover the logs and exposed sides with polyethylene. Put four to six inches of earth on the poly.
He does suggest a few tricks to make the job easier and the shelter better. For example, use the earth thrown out of the hole as part of the structure, so you don’t have to dig as deep. You want the roof sloping, not flat. On a slope, put most of the soil on the uphill side, forming a V with the pointed side uphill. This will divert surface water around the shelter, keeping it drier. Reading both books will give you many other ideas.
.
Design
The PSP construction process is simple and easily understood. But the concept of living under the ground is extremely alien to most people who haven’t been exposed to Mike Oehler’s design concepts. In addition, proper design is the single most important key to the success of an underground dwelling, in terms of light, ventilation, and most importantly, drainage.
So it’s not surprising that Mike spends most of his time and effort, in his book as well as videos, on design.
Conventional thinking (if that can be applied to something as radical as U housing) most often involves digging a hole into a hillside and plopping a structure there. A bank of windows faces downhill, while the uphill side is a solid blank wall. More often than not, if the house is on a south slope, the roof is pitched back into the hill, so drainage from the roof runs into drainage from the hillside. Leaks are almost inevitable. There is little or no air flow, the back of the house is dark and damp, and the view is limited.
Mike calls this the first-thought design. His thinking has taken him far beyond that.
The five approved methods of design
In his videos he stresses designs with views – and light and ventilation – in all four directions, and he urges viewers to try it themselves (with accompanying worksheets). Although some of the ideas are revolutionary, he simply calls them the Five Approved Methods of Design.
They are: the uphill patio; the off-set room; clerestories; the Royer foyer; and gables.
The uphill patio
The uphill patio is as useful as it is clever. It is basically a terraced garden area, with its bottom at any desired height from the floor of the house, and its top blending into the adjacent ground level. It not only solves problems of drainage and lateral thrust (the pressure of the earth on buried walls), but it can function as an emergency exit or a second entrance. It can also serve as a built-in greenhouse.
Naturally, it admits light and air, even from the uphill side of the house which would otherwise be a dark blank wall. This not only reduces kerosene or electric bills but results in more balanced lighting.
The view is up to the garden design interests and abilities of the owner, of course. Japanese courtyard gardens, which are world-renowned works of art, are offered as an example of the possibilities.
And finally, the uphill patio offers a controlled view. It’s determined by the depth of the patio and the resultant trajectory of sight. No matter what anyone builds nearby, you won’t have to look at it if you don’t want to. (If the neighbor builds a 20-story high-rise one foot from your property line, put a greenhouse covering on the patio.) And no one can see into it (or your home) unless they’re standing right on top of it.
The offset room
The basic U house design is a square or rectangular room. The simple expedient of adding a second room, and offsetting it to protrude into the uphill patio, provides the opportunity to install a section of windows which face an entirely different direction. This offers even more advantages of views, light, and ventilation. Elevating the offset room results in even more design possibilities.
The Royer foyer
The Royer foyer is a design invention which allows us to have a good view down a hill without rechanneling the flow of drainage or interrupting the purity of design of a shed roof. The Royer foyer sneaks into the hillside rather than protruding from it. It makes possible a downhill view from windows that are all but concealed from neighbors.
The foyer (named after the helper friend who came up with the idea) is a pie-shaped excavation away from the house on the side wall (not the downhill wall) of a downhill corner. It has many advantages and attributes, all discussed and illustrated in the book.
Clerestories and gables
Clerestories and gables are nothing new, but they can be valuable contributions to underground housing. As might be expected, however, there are details to consider when incorporating them into an underground PSP house… where the three primary demands are drainage, drainage, and drainage. Details are provided in the book.
Also included are discussions of earthen floors, built-in root cellars, earth coolers, a barbecue window and bachelor bar, plumbing and wiring considerations, engineering rules of thumb, scrounging materials… and everything else you’ll need to know to build your own pleasant, comfortable and affordable underground home.
Construction of an emergency shelter
You really need the book, and perhaps the videos, to get a good grasp of the construction method and, more importantly, design considerations. But many readers who don’t consider themselves candidates for building an underground house – or even a root cellar or tornado shelter – might appreciate knowing how it’s done, just in case. Mike Oehler covers this aspect in his latest book, "The Hippie’s Guide to Y2K" (see review in 83/3:110). He calls it the Pit House. It’s as simple as this:
Dig a hole. Cover it with logs. Cover the logs and exposed sides with polyethylene. Put four to six inches of earth on the poly.
He does suggest a few tricks to make the job easier and the shelter better. For example, use the earth thrown out of the hole as part of the structure, so you don’t have to dig as deep. You want the roof sloping, not flat. On a slope, put most of the soil on the uphill side, forming a V with the pointed side uphill. This will divert surface water around the shelter, keeping it drier. Reading both books will give you many other ideas.
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