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Geoff Dembicki reports extensively on the growing political influence of Alberta's oil sands industry and other climate change-related issues for TheTyee.ca, an award-winning online newspaper based in Vancouver, Canada.

Driving south from Vancouver, Canada, towards Seattle, the scenery is perfectly pastoral with rolling hills and grazing cows. But suddenly, dominating the horizon, the view is interrupted by a phalanx of refinery towers shooting white-gray plumes into the sky. These industrial spires of BP's Cherry Point refinery loom high over Whatcom county, a lush border region a little more than 100 kilometers north of Seattle.

Washington State's largest refining complex provides jet fuel, gasoline and diesel to markets up and down the west coast of North America. I had driven there on a rainy morning last month, hoping to learn more about the economic alchemy that transforms crude oil from Alberta's oil sands and elsewhere into ever ubiquitous aluminum beverage cans.

Photo by Dustin Hicks

Cherry Point plays a little known but critical role in the manufacture of these cans - in fact one-sixth of the world's output would not be possible without an industrial substance produced here in massive volumes each day.

Every year 100 billion soda, beer, and juice cans are cracked open by North Americans each year, almost one can for every person every day. That vast market suggests that transitioning off fossil fuels to halt climate change will be more complicated than the oft-proclaimed solution of switching to a greener forms of transportation.

From Alaska to Alberta

Inside a low brick building at the front of the BP refinery, I shook hands with Bill Kidd, BP's local director of external affairs. “How're you doing?” he exclaimed with a broad smile that made lines appear at the corners of his eyes.

The 52-year-old Kidd, dressed smartly in sleeveless black sweater, slacks and white dress shirt, led me to what passes here as a spacious corner office. Here he explained how Cherry Point is a showcase of North America's oil-boom past and its more troubled future. With the dwindling of easy oil that has gushed from the ground for the last century, the energy industry is in a full-bore search for rich, new reserves, including the oil sands of western Canada.

Built by the Atlantic Richfield Company (ARCO) in 1971 specifically to process crude oil shipped from Alaska's North Slope, Cherry Point was acquired by British Petroleum after the two companies merged in 2000. Today BP (the company dropped the original name in 2001) has become North America's largest oil and gas producer. The company generated profits of US$16.6 billion in 2010 even after a deadly explosion at its offshore Gulf of Mexico Macondo rig created the worst environmental disaster in U.S. history.

For over a decade, the massive Prudhoe Bay reserves and other frigid deposits nearby helped supply refineries on the west coast. Indeed Cherry Point still memorializes those early glory days with a four-foot tall sculpture of a flower with sheet metal petals surrounding an old Prudhoe Bay drill bit.

But production, which peaked at 2.1 million barrels per day in 1989, “has fallen off a cliff,” Kidd told me. Today, daily yield has plummeted to just over 600,000 barrels.  

The refinery now sources only half its oil from Alaska, with places as varied as West Africa and Russia helping make up the difference, Kidd said. Most significantly, up to 14 percent of Cherry Point's current crude supply can be traced back to Alberta's vast oil sands reserves, according to trade research conducted by the Borealis Centre for Environment and Trade Research, based on data from the U.S. Department of Energy.

“How much we use specifically is sensitive information,” Kidd told me when I asked him about the figure. “But that is not an outlandish number.”

From Crude to Can

About 90 percent of the crude oil that gets pumped into Cherry Point comes out as gasoline, diesel and jet fuel - the bread and butter of North America's refining industry. But the Washington state complex is unique in that it is one of the world's leading providers of a substance essential to the aluminum industry.

When transportation fuels are separated from crude oil, they leave behind a tarry residue. Break down that substance with high temperatures and pressure, and it becomes petroleum coke, a valuable industrial solid. Petcoke, as it is known, gives off intense heat when it burns, making it ideal for the production of cement, steel and certain specialty chemicals. It is also extremely carbon-intensive, releasing almost double the greenhouse emissions of natural gas.

At Cherry Point, some of this petcoke is sent via conveyor belt to the calciner, a collection of large hearths that Kidd compared to a “2,300F degree coffee roaster.”

The finished product, “calcined coke,” is then loaded onto tankers and shipped to aluminum smelters in Australia, Brazil, New Zealand, Canada, and South Africa, according to Borealis. Those smelters in turn outsource their metal to beverage can producers around the world.

When you follow the supply chain all the way back, “one in six aluminum cans is made using BP Cherry Point's calcinated coke,” the company's website brags.

It used to be that most of the refinery's output stayed onshore, Kidd said. Only a generation ago, the U.S. aluminum industry was thriving, shipping 7.3 million tons of metal in 1973, up 21 percent from the year before.

But a booming trend towards global trade hit domestic smelters fast and hard. “Nearly all our aluminum in the next century is probably going to come from offshore countries,” a spokesperson from Ferndale's smelter, only a few kilometers south of Cherry Point, lamented in 1986. The industry could not escape the same economic factors that killed off domestic steel production: relatively high labor and energy costs.

Energy Security

Tune into any discussion on the future of U.S. oil supply and you're going to hear the phrase “energy security” an awful lot. . The debate's gained even more urgency since the Paris-based International Energy Agency (IEA) announced late last year that world conventional oil production likely peaked in 2006.

Critics of continued reliance on fossil fuels argue that these dwindling conventional oil reserves mandate a switch to renewable or even nuclear power. The oil industry however is banking on a different strategy. Notably Republican legislators in the U.S., oil industry lobbyists and Canada's own prime minister, Stephen Harper, have seized onto this fear as a way to promote the oil sands business.

Cherry Point, by relying on the oil sands for up to 14 percent of its crude supply, is helping push the shift from crude oil to unconventional sources. And though the refinery isn't currently considering the pricey upgrades that would let it process even more, BP's Kidd said the prospect isn't too hard to imagine.

“This refinery was built when you had a huge pool of crude in Alaska, the biggest gasoline markets in the world in California and we were right in between. Now you're just moving the supply a little bit east,” he said. “I think it's reasonable to think that more [oil sands] will come this way.”

The refinery's supply-chain narrative - once mighty oil fields in decline, greater reliance on higher-carbon unconventional sources - is being replayed globally. Other North American refineries - such as BP's Whiting complex in Indiana - have invested billions of dollars to handle fast-growing shipments of oil sands crude.

The plan to bring the oil industry into line with changing conditions also includes Keystone XL, a proposed 3,200 kilometer mega-pipeline that travels south from the Canadian province of Alberta to refineries lining the Gulf coast of Texas.

Supporters such as TransCanada, the company proposing to build it, say Keystone XL would “reduce dependence on foreign oil from the Middle East and Venezuela,” and thereby “improve U.S. energy security.”

Toxic “Mordor”

One of the main reasons why environmental activists oppose this strategy is the impact that the extraction of oil sands have on the province of Alberta, a thousand kilometers to the north west of Cherry Point.

There are up to an estimated 2.5 trillion barrels of crude waiting to be extracted in Alberta. This makes the oil sands North America's largest single source of petroleum, far surpassing Saudi Arabia. But developing those reserves is not an easy - or pretty -- task. Each barrel of oil sands crude must either be clawed from frigid muskeg bogs with industrial-scale shovels, or melted out of underground formations with high-pressure steam and toxic chemicals.

A United Nations water advisor in 2008 compared the region's strip-mined panoramas and sprawling toxic lakes to Mordor, the fictional dark realm of Middle Earth created by J. R. R. Tolkien.

“The air is foul, the water is being drained and poisoned and giant tailing ponds line the Athabasca River,” Canadian environmentalist and author Maude Barlow said at the time.

Alberta's oil sands industry also produces 23 percent more greenhouse gas emissions per barrel than more conventional operations such as those in Prudhoe Bay, a recent European Union report estimated.

The provincial government has argued that report is “unfair” because it uses out-of-date figures. And in 2009 outgoing premier Ed Stelmach told an economic forum in Geneva, Switzerland, that “no matter which extraction method is used, Alberta has some of the most stringent environmental regulations in the world.”

Climate Change Threat

The other reason that critics cite in opposing the oil sand industry is global warming. Only days after I drove to Cherry Point, delegates from more than 180 countries were gathering in Bonn, Germany, for two weeks of climate talks. The mood on day one was sombre as they were confronted by an IEA report showing that greenhouse gases were at record highs, despite 20 years of attempts to control them.

“A serious setback,” is how the IEA's chief economist, Fatih Birol, described the figures.

Part of the reason is that global oil consumption is not going down even though supplies of easy-to-access conventional oil, the very commodity that made a global trade in aluminum cans possible, likely peaked five years ago, as the IEA pointed out last November.

Instead the IEA expects that oil sands, oil shale and extra heavy crude - among the most greenhouse gas-intensive fuel sources on the planet - are filling the gap and are projected to make up roughly 11 percent of global supply by 2030.

This trend “risks tipping the world over the brink in terms of climate damage,” according to a 2010 report by Friends of the Earth Europe.

Yet a radical shift in global efforts to fight climate change -one of the most pressing crises in human history -- seems less and less likely each year. If the world's nations can't limit the Earth's average temperature rise to two degrees above pre-industrial levels, scientists predict that everything from global agriculture to the world's coastal cities will be in peril.

Many environmentalists believe the Obama administration can make a difference by canceling TransCanada's Keystone XL proposal, a pipeline that would pump 800,000 barrels of high-carbon Alberta oil sands crude into the U.S. every day.

“The best way to build energy security in America is through clean, home-grown sources of energy that won't run out -- such as wind and solar for electric vehicles and fuel efficiency and smart growth to reduce our dependence on oil,” Natural Resources Defense Council's Susan Casey-Lefkowitz wrote earlier this year.

Yet switching power and transportation sources are only part of the answer. Closing up my interview at the Cherry Point refinery, I asked Kidd how North America can possibly square its global warming goals with a fossil fuel industry so ubiquitous it's difficult to imagine life without it.

“Obviously,” he replied, the smile now gone from his face, “we're going to have to do something radically different.”

I asked Kidd one final question: “Could we have a global pop, beer and juice can industry without crude oil?”

“Nope,” he replied. “Hydrocarbons in general are incredibly ubiquitous in our economic engine. It isn't just transportation fuel that will be the issue.”

On my drive back to Vancouver I saw crude oil wherever I looked - like an invisible coating on every concrete overpass, eighteen-wheeler semi-truck and pop can discarded on the side of the road.

The question of “energy security” had never seemed so complex.

Source: CorpWatch.org

 

By adjusting these fields, the transmission of nerve impulses becomes possible and the operation of modern data storage is fulfilled by saving electrical charges (so-called Flash Memories). What researchers have not been able to do is get an ultra-precise reading of electrical fields by using physical measurement techniques. Until now, that is. With the help of one single defect centre in diamond, scientists at the University of Stuttgart in Germany successfully measured electrical fields. Presented in the journal Nature Physics, the study was funded in part by the EU.

Diamond center defect helps scientists measure electrical fields

Electrical charges use varied ways to control almost 100 % of all physical, chemical or biological processes. A case in point is deoxyribonucleic acid (DNA) and the exact distribution of electrons on it. This distribution is critical for the precise transmission of genetic information, and modern electric circuits trigger electric currents up to single electrons.

Experts say that measuring minor electronic fields linked to the charge is no easy task. Enter the Stuttgart team that devised a new sensor consisting of just one single atom. This nitrogen atom is an impurity captured in diamond, they say.

The team points out that the diamond lattice 'fixes' the atom and enables a laser to address the nuclear vacancy center. "The interaction of the atom with the measured field can be determined by the light emitted by the impurity and, therefore, electrical fields can be measured which are just a fracture of theelectrical field of an elementary charge in 0.1 um distance," the scientists explain.

Because the sensor is about the size of an atom, scientists can measure electrical fields with the same spatial precision. The sensor-generated optical readout enables it to be placed in any geometry. The process also attains its sensitivity and resolution at room temperature and ambient conditions.

While researchers have succeeded in demonstrating the existence of small magnetic fields, this latest finding of combining both measurement techniques permits the measurement of electrical and magnetic fields in a single place without changing the sensor, the team points out.
Thanks to this latest development, novel applications can and will emerge. Measuring the magnetic moments' distribution of the chemical compounds' nuclei at the same time is an example, they say, adding that the structure of a substance and its chemical reactivity can be measured simultaneously.

"The ability to sensitively detect individual charges under ambient conditions would benefit a wide range of applications across disciplines," the authors write. "However, most current techniques are limited to low-temperature methods such as single-electron transistors, single-electron electrostatic force microscopy and scanning tunnelling microscopy. Here we introduce a quantum-metrology technique demonstrating precision three-dimensional electric-field measurement using a single nitrogen-vacancy defect centre spin in diamond."

Source: PhysOrg

 

Around the world, there are more than one billion cars, and in the United States alone, over 250 million of those cars sit idle 93 percent of the time in driveways and parking lots.

Combing the peer-to-peer Samaritanism of couch surfing with the automotive green initiatives of Zipcar, some new startup carsharing companies are aiming to revolutionize how people view personal vehicles   through networks of idle cars readily availble for rent.

Car-share-650

Photo: Anne Rippy/Getty Images

For companies such France's Buzzcar and San Fransisco's Getaround, the concept is simple. Car owners or renters sign up online, making available either their cars or their desire to rent one. Owners decide hourly rental rate and the companies cover the insurance. Members then browse available cars located in their area, arrange a key swap, and off you go. For Getaround cars equipped with their carkit-enable RFID systems, renters can download the Getaround app to their smartphone, allowing users to rent and unlock cars without owners needing to be physically present.

The business model looks to expand on traditional, fleet-based carsharing providers, such as Zipcar that still rely on a limited number of new vehicles in select locations. Getaround and Buzzcar hope to tap into the vast community of available vehicles, potentially turning all cars into shared vehicles.

"People who live in tiny towns or out in rural areas can add their cars into the network. Then, when a neighbor needs a pickup, or their adult children are visiting and they need another car, or their own car in out of commission, they can rent a neighbors car, Buzzcar founder, Robin Chase told Discovery News in an email. Chase is also co-founder and former CEO of Zipcar.

Source: DiscoveryNews

 

In work recently published in the Journal of Applied Physics, a UTS research team supervised by Professor Guoxiu Wang has developed reproducible test results and nanostructural samples of graphene paper, a material with the potential to revolutionise the automotive, aviation, electrical and optical industries.

Graphene paper (GP) is a material that can be processed, reshaped and reformed from its original raw material state - graphite. Researchers at UTS have successfully milled the raw graphite by purifying and filtering it with chemicals to reshape and reform it into nano-structured configurations which are then processed into sheets as thin as paper.

A breakthrough on paper that's stronger than steel

These graphene nanosheet stacks consist of monolayer hexagonal carbon lattices and are placed in perfectly arranged laminar structures which give them exceptional thermal, electrical and mechanical properties.

Using a synthesised method and heat treatment, the UTS research team has produced material with extraordinary bending, rigidity and hardness mechanical properties. Compared to steel, the prepared GP is six times lighter, five to six times lower density, two times harder with 10 times higher tensile strength and 13 times higher bending rigidity.

Lead researcher Ali Reza Ranjbartoreh said, "No one else has used a similar production and heat testing method to find and carry out such exceptional mechanical properties for graphene paper. We are definitely well ahead of other research societies."

"The exceptional mechanical properties of synthesised GP render it a promising material for commercial and engineering applications.

"Not only is it lighter, stronger, harder and more flexible than steel it is also a recyclable and sustainable manufacturable product that is eco-friendly and cost effective in its use."

Mr Ranjbartoreh said the results promise great benefits for the use of graphene paper in the automotive and aviation industries, allowing the development of lighter and stronger cars and planes that use less fuel, generate less pollution, are cheaper to run and ecologically sustainable.

He said large aerospace companies such as Boeing have already started to replace metals with carbon fibres and carbon-based materials, and graphene paper with its incomparable mechanical properties would be the next material for them to explore.

The production of GP from graphite also provides a remarkable amount of added value for the mining, material processing and manufacturing industries in Australia. In the last decade, metals have increasingly and rapidly been replaced with carbon-based materials.

Australian mines have immense graphite resources making the new material a favourable option to industry as an economical, home-grown and world-class technological advancement for mass production and industrial application.

The findings of the UTS research group have been published in the article "Advanced mechanical properties of graphene paper" in the current edition of the Journal of Applied Physics.

Source: physorg

More information: http://jap.aip.org … 1/p014306_s1

Provided by University of Technology, Sydney

 

This may come as a shock considering how seriously Facebook takes your privacy, but if you’re a Facebook user with one of Facebook’s mobile applications installed on your iPhone or one of several other smartphones, you’ve been robbed. Each and every contact stored on your phone is probably now also stored on Facebook’s servers, as was re-re-rediscovered by Facebook users this past week. Whether or not people in your contact list even have Facebook accounts, their names and phone numbers are likely now in Facebook’s possession. There is probably a clause buried deep within Facebook’s terms and conditions that makes this invasion of your privacy OK on paper, but odds are still pretty good that it’s not OK with you. Complete instructions outlining how to remove all of your contacts’ phone numbers from your Facebook account can be found below. Whether or not the data will be completely wiped from Facebook’s servers is unclear, but we’ll leave that for the lawyers to figure out.

UPDATE: A Facebook spokesperson delivered the following official statement to BGR via email: “Rumors claiming that your phone contacts are visible to everyone on Facebook are false. Our Contacts list, formerly called Phonebook, has existed for a long time. The phone numbers listed there were either added directly to Facebook and shared with you by your friends, or you have previously synced your phone contacts with Facebook. Just like on your phone, only you can see these numbers.”

  1. Visit facebook.com from a PC and log in
  2. in the top-right corner of the screen, click on Account and then Edit Friends
  3. In the menu on the left side of the screen, click on Contacts
  4. Here, you will see that each and every one of your contacts in Address Book are listed along with their phone numbers… wipe the look of shock and disgust from your face
  5. On the right side of the screen, click on the “this page” link
  6. Follow the instructions on this page — you’ll have to disable contact-sync in Facebook’s mobile app if it’s enabled — and click the Remove button

Note: Many users note that Facebook’s mobile apps now carry disclaimers that mention the fact that Facebook is taking your data. Of course Facebook does currently include a disclaimer, though the wording makes no mention of this data being stored on its servers until manually deleted by the user. Even still, this has not been the case with all versions of the app, and there are also numerous reports from users who claim to have never synchronized their contacts with Facebook’s mobile apps, yet still find all of their contact data stored on Facebook’s servers.

Thanks, Kamar

Author: Zach Epstein - Source: bgr.com

 

An Indiana state Representative, who recently voted for a constitutional amendment that would ban gay marriage, has been accused of using Craigslist to offer an 18-year old male $80 for "a couple hours of your time tonight" plus a tip "for a really good time."

The Indianapolis Star obtained e-mails sent from Rep. Phillip Hinkle's (R) publicly listed personal address, responding to a Craigslist posting by Kameryn Gibson that said "I need a sugga daddy." Gibson told the Star that the post was in the "Casual Encounters" section under m4m, or men for men. He used his sister Megan's e-mail address -- and she later sent the e-mails to the Star.

Rep. Phillip Hinkle (R-IN)

"Cannot be a long time sugar daddy," says the e-mail response from what is allegedly Hinkle's address, "but can for tonight. Would you be interested in keeping me company for a while tonight?"

"I am an in shape married professional, 5'8", fit 170 lbs, and love getting and staying naked," the e-mail says.

Another e-mail says: "If u want to consider spending night u might tell ur sis so she won't worry. Would have u back before 11 tomorrow. No extra cash just free breakfast and maybe late night snack."

The Star reports:

The young man told The Star that they met, but that he tried to leave after the man told him he was a state lawmaker. He said the lawmaker at first told him he could not leave, grabbed him in the rear, exposed himself to the young man and then later gave him an iPad, BlackBerry cellphone and $100 cash to keep quiet.
Gibson had his sister pick him up, who says that she then received a number of calls, and one was from a woman who claimed she is Hinkle's wife. "I was like, 'Your husband is gay,'" Megan Gibson said. "And then she was like, 'You have the wrong person.'" When Gibson reportedly read back the e-mail address used for the Craigslist ad, the woman asked her not to call the police.

Megan Gibson told the Star that later that evening she went back to the JW Marriott to show Hinkle's daughter the e-mails. She soon after received another phone call from the woman claiming to be Gibson's wife, who offered her $10,000 not to tell anyone. Still another call came from Hinkle himself later, and she told him what she had told his family members. "You just ruined me," she says Hinkle responded.

Hinkle did not deny the e-mails in response to the Star's request for comment, but said: "I am aware of a shakedown taking place." He did not elaborate on what "shakedown" meant, nor did his attorney.

Read the full report here.

Hinkle recently voted for an amendment (.pdf) to the state's constitution that would define marriage as between a man and a woman.

Late Update: Gov. Mitch Daniels (R) weighed in on the allegations on Friday, telling reporters that he is "sad about it."

"It's not for me to say [whether Hinkle should resign]," Daniels said. "It's for him and his constituents. It's just a personal family tragedy."

Source: tpmmuckraker.talkingpointsmemo.com - Author: Jillian Rayfield

 

Utilizing the friendship paradox - the idea that a person's friends are likely more popular than they are - the researchers were able to follow groups closer to the center of a network without the tedious and difficult chore of fully mapping social networks. Members closer to the center of a network have contact with more people and are more likely to contract any contagious disease than people toward the outskirts of the group.

Social Networks Predict Disease Spread

Dr. Nicholas Christakis of the Harvard Medical School and his collaborator Dr. James Fowler at UCSD tracked 319 randomly selected Harvard students through the 2009 flu season as well as 425 students named as friends by the original group using two different methods of identifying the flu. The flu manifested itself in the friends group two weeks sooner than in the random group using one identification method and 46 days sooner using the other method.

The sooner outbreaks of infectious disease are identified, the sooner they can be treated and, hopefully, contained. Even a two week head start as seen in the more conservative identification method could make an enormous difference in the size and severity of a major outbreak. That said, it's likely the amount of lead time inherent in this method will likely vary from case to case depending on the specifics of the infection and the details of the network. It also depends on actively monitoring a network likely to be affected by disease before it strikes.

In addition to tracking infection diseases, the friends paradox could also be used to track other things that spread out among groups of people including trends, the adoption of specific behaviors, and the effectiveness of marketing campaigns.

TFOT previously reported on another social networking research project involving the voluntary publication of data collected via RFID chips, the decision by the individuals of who individuals should see the information and what data they decide to delete or retain for public consumption. TFOT also reported on the origins and spread of infectious diseases including a historical overview of smallpox and a video about the H1N1 flu epidemic.

Source: TheFutureOfThings.com

 

Their Gravity Power Modules would marry traditional heavy rig drilling technology with renewable energy storage.

 

At utility-scale, the pumped storage would begin with drilling thousands of feet underground, large enough to accommodate an 18 foot diameter storage shaft and a 6 foot diameter return pipe.

Here’s how it works, in the elegant words of Powermag:

“At the bottom of the shaft is a large concrete piston fitted to the shaft, called the “weight stack.” Also bored into the ground is a parallel but smaller-diameter “return pipe” that is connected to the main shaft at the top and bottom.

Finally, the entire volume is filled with water and tightly sealed—air is compressible and its presence reduces the system effectiveness. In essence, the position of the weight stack in the shaft determines the amount of energy stored.

During the energy storage process, off-peak electricity is used to power a pump that pushes water down the return pipe that will raise the weight stack from the bottom of the deep storage shaft.

During a peak electricity demand period, the weight stack is released, which pushes the water up the return pipe, reversing the direction of rotation of the pump-turbine and producing electricity, much as in a typical pumped storage hydroelectric plant.”

CEO Jim Fiske envisions that his Gravity Power Modules would be installed in clusters to produce the amount of energy desired. The storage capacity of a 7 acre site could amount to more than 2 GW (2,000 MW) depending on the depth and diameter of the shafts.

The Gravity Power Module has a conversion efficiency that looks likely to be in the 75% to 80% range once it is tested at full scale, at installation costs a little higher pumped hydro, around $150/kWh for a system capable of storing about 200 MWh.

Pumped hydro installation has installation costs of around $100/kwh. But it can be controversial because, like hydro-electricity itself, pumped hydro can impact a natural habitat for fish. More than half the states that have renewable energy standards do not allow hydro to qualify as renewable because of the ecological damage.

New pumped hydro projects face formidable permitting obstacles, despite the need to add more energy storage as we move to a clean power economy. The Gravity Power Module could be one of the solutions.

Source: CleanTechnica

 

Researchers at MIT have found a way to make significant improvements to the power-conversion efficiency of solar cells by enlisting the services of tiny viruses to perform detailed assembly work at the microscopic level.

In a solar cell, sunlight hits a light-harvesting material, causing it to release electrons that can be harnessed to produce an electric current. The new MIT research, published online this week in the journal Nature Nanotechnology, is based on findings that carbon nanotubes — microscopic, hollow cylinders of pure carbon — can enhance the efficiency of electron collection from a solar cell's surface.

Previous attempts to use the nanotubes, however, had been thwarted by two problems. First, the making of carbon nanotubes generally produces a mix of two types, some of which act as semiconductors (sometimes allowing an electric current to flow, sometimes not) or metals (which act like wires, allowing current to flow easily). The new research, for the first time, showed that the effects of these two types tend to be different, because the semiconducting nanotubes can enhance the performance of solar cells, but the metallic ones have the opposite effect. Second, nanotubes tend to clump together, which reduces their effectiveness.

In this diagram, the M13 virus consists of a strand of DNA (the figure-8 coil on the right) attached to a bundle of proteins called peptides — the virus coat proteins (the corkscrew shapes in the center) which attach to the carbon nanotubes (gray cylinders) and hold them in place. A coating of titanium dioxide (yellow spheres) attached to dye molecules (pink spheres) surrounds the bundle. More of the viruses with their coatings are scattered across the background. 
Image: Matt Klug, Biomolecular Materials Group.

And that’s where viruses come to the rescue. Graduate students Xiangnan Dang and Hyunjung Yi — working with Angela Belcher, the W. M. Keck Professor of Energy, and several other researchers — found that a genetically engineered version of a virus called M13, which normally infects bacteria, can be used to control the arrangement of the nanotubes on a surface, keeping the tubes separate so they can’t short out the circuits, and keeping the tubes apart so they don’t clump.

The system the researchers tested used a type of solar cell known as dye-sensitized solar cells, a lightweight and inexpensive type where the active layer is composed of titanium dioxide, rather than the silicon used in conventional solar cells. But the same technique could be applied to other types as well, including quantum-dot and organic solar cells, the researchers say. In their tests, adding the virus-built structures enhanced the power conversion efficiency to 10.6 percent from 8 percent — almost a one-third improvement.

This dramatic improvement takes place even though the viruses and the nanotubes make up only 0.1 percent by weight of the finished cell. “A little biology goes a long way,” Belcher says. With further work, the researchers think they can ramp up the efficiency even further.

The viruses are used to help improve one particular step in the process of converting sunlight to electricity. In a solar cell, the first step is for the energy of the light to knock electrons loose from the solar-cell material (usually silicon); then, those electrons need to be funneled toward a collector, from which they can form a current that flows to charge a battery or power a device. After that, they return to the original material, where the cycle can start again. The new system is intended to enhance the efficiency of the second step, helping the electrons find their way: Adding the carbon nanotubes to the cell “provides a more direct path to the current collector,” Belcher says.

The viruses actually perform two different functions in this process. First, they possess short proteins called peptides that can bind tightly to the carbon nanotubes, holding them in place and keeping them separated from each other. Each virus can hold five to 10 nanotubes, each of which is held firmly in place by about 300 of the virus's peptide molecules. In addition, the virus was engineered to produce a coating of titanium dioxide (TiO2), a key ingredient for dye-sensitized solar cells, over each of the nanotubes, putting the titanium dioxide in close proximity to the wire-like nanotubes that carry the electrons.

The two functions are carried out in succession by the same virus, whose activity is “switched” from one function to the next by changing the acidity of its environment. This switching feature is an important new capability that has been demonstrated for the first time in this research, Belcher says.

In addition, the viruses make the nanotubes soluble in water, which makes it possible to incorporate the nanotubes into the solar cell using a water-based process that works at room temperature.

Prashant Kamat, a professor of chemistry and biochemistry at Notre Dame University who has done extensive work on dye-sensitized solar cells, says that while others have attempted to use carbon nanotubes to improve solar cell efficiency, “the improvements observed in earlier studies were marginal,” while the improvements by the MIT team using the virus assembly method are “impressive.”

“It is likely that the virus template assembly has enabled the researchers to establish a better contact between the TiO2 nanoparticles and carbon nanotubes. Such close contact with TiO2 nanoparticles is essential to drive away the photo-generated electrons quickly and transport it efficiently to the collecting electrode surface.”

Kamat thinks the process could well lead to a viable commercial product: “Dye-sensitized solar cells have already been commercialized in Japan, Korea and Taiwan,” he says. If the addition of carbon nanotubes via the virus process can improve their efficiency, “the industry is likely to adopt such processes.”

Belcher and her colleagues have previously used differently engineered versions of the same virus to enhance the performance of batteries and other devices, but the method used to enhance solar cell performance is quite different, she says.

Because the process would just add one simple step to a standard solar-cell manufacturing process, it should be quite easy to adapt existing production facilities and thus should be possible to implement relatively rapidly, Belcher says.

The research team also included Paula Hammond, the Bayer Professor of Chemical Engineering; Michael Strano, the Charles (1951) and Hilda Roddey Career Development Associate Professor of Chemical Engineering; and four other graduate students and postdoctoral researchers. The work was funded by the Italian company Eni, through the MIT Energy Initiative’s Solar Futures Program.

Source: MITnews

 

Procuratura din Manhattan va cere marti retragerea tuturor acuzatiilor formulate impotriva lui Dominique Strauss-Kahn, au declarat surse judiciare, citate de New York Post, in editia online de duminica.

Acuzarea urmeaza sa depuna o motiune in care va recunoaste ca acuzatiile nu pot fi dovedite dincolo de orice indoiala, din cauza problemelor de credibilitate ale reclamantei.

Surse din cadrul procuraturii au afirmat ca este posibil ca motiunea sa includa si detalii care nu au fost inca dezvaluite in legatura cu camerista care l-a acuzat pe Dominique Strauss-Kahn de agresiune sexuala.

Potrivit New York Post, magistratii aproba in general acest tip de motiune pe loc, ceea ce inseamna ca fostul director FMI ar putea pleca spre Franta in scurt timp.

Biroul procurorului din Manhattan a convocat-o pe Nafissatou Diallo pentru luni la pranz, cu o zi inaintea urmatoarei audieri a lui Dominique Strauss-Kahn. Avocatul ei, Kenneth Thompson, a declarat sambata ca este convins ca nu poate explica aceasta convocare decat prin faptul ca procuratura va renunta complet la acuzatii sau va retrage o parte dintre acestea.

Sursa: bzi.ro

 
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