JOHANNESBURG ? Some questions and answers about the climate talks being held in South Africa's eastern city of Durban that opened Monday and close on Dec. 9.
___
Q: Who is meeting in Durban?
A: Negotiators from the European Union and 191 countries making climate change policy under the auspices of the United Nations Framework Convention on Climate Change. Thousands of activists and experts are there to observe, advise and protest. The meeting is not a summit, but some heads of state will come, and government ministers from about 100 countries will attend the final days next week.
___
Q: What are the main points of contention?
A: Whether industrial countries will extend their commitments to further reduce the carbon emissions that cause global warming after their current commitments under what is known as the Kyoto Protocol expire next year. Most wealthy countries have said agreement is conditional on developing countries like China, India and Brazil accepting that they, too, must accept legally binding emissions restrictions.
? Whether progress will be made on a Green Climate Fund to help poor countries cope with climate change. A committee of 40 countries worked for the past year on drawing up a plan to administer the fund, but agreement on the final paper was blocked by the United States and Saudi Arabia, and the final contentious issues will have to be worked out in Durban.
___
Q: What is the Kyoto Protocol?
A: Under this measure adopted in Kyoto, Japan in 1997, industrialized nations are required to reduce their carbon emissions. The United States has never signed Kyoto, but is participating in the Durban talks.
___
Q: What is climate change?
A: The overwhelming majority of climate scientists say the earth's surface temperatures have been rising rapidly because man is burning fossil fuels such as coal and oil. Studies show the rising heat already has led to animals migrating, crop yields decreasing, glaciers shrinking and shore lines shifting. Developing nations, where overwhelmingly poor populations are vulnerable and infrastructure is fragile, are particularly hard hit, leading to calls on industrialized nations that got a head start on pumping greenhouse gases into the atmosphere to do, and pay, more to deal with the results.
Tom Wroblewski, center, president of Boeing Machinists Union District Lodge 751, announces Wednesday, Nov. 30, 2011, that the Boeing Co. and the Machinists union had reached a tentative agreement to build the new Boeing 737 MAX airplane in Renton, Wash., and enter into a new four-year labor contract. Looking on at right is Machinists Union aerospace coordinator Mark Blondin. (AP Photo/Ted S. Warren)
Tom Wroblewski, center, president of Boeing Machinists Union District Lodge 751, announces Wednesday, Nov. 30, 2011, that the Boeing Co. and the Machinists union had reached a tentative agreement to build the new Boeing 737 MAX airplane in Renton, Wash., and enter into a new four-year labor contract. Looking on at right is Machinists Union aerospace coordinator Mark Blondin. (AP Photo/Ted S. Warren)
Tom Wroblewski, center, president of Boeing Machinists Union District Lodge 751, announces Wednesday, Nov. 30, 2011, that the Boeing Co. and the Machinists union had reached a tentative agreement to build the new Boeing 737 MAX airplane in Renton, Wash., and enter into a new four-year labor contract. (AP Photo/Ted S. Warren)
SEATTLE (AP) ? A contentious labor dispute between the government and Boeing Co. that spawned a national political fight likely will be settled after the company and the Machinists union announced Wednesday they'd reached a tentative deal on a new four-year collective bargaining agreement.
If the deal is finalized, it would appear to leave in place the work at a new $750 million Boeing plant in South Carolina, a right-to-work state where the company opened a new production line for its 787 airplane.
The National Labor Relations Board filed a lawsuit earlier this year alleging that Boeing violated labor laws by opening the South Carolina line. Acting on a complaint from the union, the agency claimed that Boeing was punishing Washington state workers for past strikes and said the company should return the work to Washington.
Boeing has vigorously denied the charges, claiming it opened the South Carolina plant for valid economic reasons.
The new agreement guarantees that a different aircraft ? the 737 Max ? would be assembled at union facilities in Renton, Washington, said Tom Wroblewski, president of Machinists Union District 751.
Wroblewski said that if union members vote to approve the deal in the coming weeks, the union would inform the NLRB that it has no further grievances with Boeing.
Boeing spokesman Tim Healy called the new contract with the union "a starting point of a new relationship with the IAM."
Gary Chaison, professor of industrial relations at Clark University, said the union seems to have used the South Carolina dispute as leverage to guarantee other unionized jobs in the Seattle area, but on a different plane.
The labor board brought its lawsuit at the request of the union, so if the union no longer has a dispute, the board likely would stop pursuing the case.
The case became a major political issue, with Republican presidential candidates using it to bash the Obama administration. While the labor board is an independent agency, it is dominated by appointees of President Barack Obama, and settlement of the Boeing case removes a potentially damaging element for Obama in the 2012 campaign.
South Carolina Gov. Nikki Haley and the state's congressional delegation had expressed outrage at the NLRB lawsuit, saying it threatened thousands of jobs and millions of dollars invested in the new Boeing facility in Charleston.
Union members in Washington, Oregon and Kansas are scheduled to vote Dec. 7 on the tentative agreement. It calls for annual wage increases of 2 percent, cost-of-living adjustments, an incentive program intended to pay bonuses between 2 percent and 4 percent, a ratification bonus of $5,000 for each member, and improvements in the pension program. But it also would raise workers' share of health costs.
Boeing is building its new 787 in Washington state, but opened a second ? non-union ? assembly line in Charleston. The NLRB complaint arose because it said Boeing opened the second plant to avoid legal union strikes in Washington.
Boeing appeared to be considering a similar move for an updated 737 it plans to build. Those planes are built in Renton, Washington, now, but Boeing said in July it was studying other locations in addition to Renton for the new 737.
Boeing said on Wednesday that it will make the 737 with the new engine in Renton if workers ratify the new contract.
Haley had insisted that Republican presidential candidates talk about the issue as they courted voters in South Carolina, the first-in-the-South primary state. Candidates slugged away at it early and often. Mitt Romney took an early swing in May as made his first pre-campaign stop and laid the blame Obama's feet.
"How in the world can the president justify the federal government taking power from South Carolina and not allowing South Carolina to compete on a fair and level playing field," Romney said. "It's simply inexcusable."
Haley spokesman Rob Godfrey said the governor "believes this is a great win for Boeing to come to an agreement with the Machinists, and it confirms what we have always said: The NLRB is nothing but a tool for President Obama to bully our businesses."
___
Hananel reported from Washington. Associated Press writers Joshua Freed in Minneapolis and Jim Davenport in Columbia, South Carolina, contributed to this report.
Clichés Warner Bros. needs to avoid in trailer, which premieres December 16, in this edition of <i>The Weekly Rising.</i> By Kevin P. Sullivan
Christian Bale and Tom Hardy film "Dark Knight Rises" Photo: Getty Images
A great trailer is a challenge to pull off. It needs to strike a delicate balance between not showing enough and giving everything away. A trailer establishes the tone and look of a film without getting too deep into the story to ruin the actual movie.
The pressure is now on for "The Dark Knight Rises" and its theatrical trailer, which will premiere in front of "Sherlock Holmes: A Game of Shadows" on December 16. With so many looking forward to the conclusion of Christopher Nolan's Batman trilogy, the first full-length trailer needs to make the appropriate impact. Unfortunately, a great trailer doesn't always get made. Studio execs can tinker with it into oblivion in the hopes of hitting all four quadrants.
Here's an outline for the "Dark Knight" trailer I don't want to see.
Vrooommmm, tick, tick, tick, tick, tick.
Fade into the Warner Bros. logo surrounded by falling building debris, just like the teaser trailer.
Vrooommmm, tick, tick, tick, tick, tick.
Fade into the Legendary Pictures logo surrounded by falling building debris, just like the teaser trailer.
Vrooommmm, tick, tick, tick, tick, tick.
Suddenly, an "Inception"-esque Bwooonnng! rings outs to remind everyone of how much we all liked that movie. That's always a good way to get people's attention. Every other vaguely sci-fi action movie since last summer has used it in their trailer. Why shouldn't we?
We pan over the Gotham cityscape. Pay no attention to the fact that it doesn't look like Chicago anymore. This is just a different part of the city, the Little Pittsburgh district. From that, we take a closer look at the city. It's seven years later and things aren't great. The homeless riddle the streets. Someone smashes a window with a brick. A street vendor feeds his kids the falafel he sells from his cart.
"Gotham!" yells the muffled voice of Tom Hardy, as the villainous Bane, in a voice-over, sounding kind of like an elderly British woman. "Take back your city!" While the voice speaks, we cut to a slightly older Commissioner Gordon staring at the broken Bat signal, then John Blake slamming some handcuffed punk against the hood of a car. Finally, there's a slow fade onto Bruce Wayne. He's staring at his Batsuit, stored behind a thick pane of glass in the fully restored Batcave.
Transition to soft piano music. Tell Hans to string together four or five chords. Play them each 10 seconds apart. This will let them know there's some really heavy stuff going on here. "Master Wayne?" Alfred calls from the top of the stairs. He's in his bathroom, and it's clearly late. Bruce turns to look at his loyal butler.
"Are you all right?" Alfred asks, with sadness in his face. We're back with Bruce. He turns to face the encased suit and studies it for a moment. "I'm fine."
Now tell Hans to start up that cool chanting he had all those nerds do online. The one they yelled into their parents' computer.
Deshy! Deshy!
Bah-Sah-Rah! Bah-Sah-Rah!
The citizens are gathering, and it's not for "The Taste of Gotham" — that's next week. They're revolting. There are riots in the streets. Things are on fire. People are jaywalking all over the place. It's chaos! Everyone in Gotham is heading in one direction, toward something that looks like courthouse steps.
Toward Bane! He's there in his new fur-lined coat from the Burlington Coat Factory. He watches as people approach him and the mercenaries flank him on each side. The picture of Harvey Dent is in his hand. The mercenaries drag forward a hostage. He looks like a businessman, clearly some government type. Let Nolan figure it out. Bane is going to kill him.
We're back in the Batcave. Bruce watches on a set of monitors everything that's taking place. When he sees the hostage, he bolts for his suit. Finally decked out as Batman, he heads for the Batpod, but someone is already there. It's Catwoman! She kicks the bike to life and takes off out of the cave. "Perfect," Batman says.
From there, just cut together a few seconds of each awesome set piece, and let the audience know about everything cool that's going to happen.
Bane and Batman fight. Batman leads the police against Bane and his army of ticked-off citizens. Hint at the origin of Bane. We finish at a party. Alfred brings Bruce over to a most delightful young lady he just met. He's hoping to get his master over the whole "Rachel blew up" thing. We approach a raven-haired beauty from behind.
"Master Bruce, I have to introduce you to the most delightful young lady. Miss, you were saying your name was?" She turns. "Selina Kyle."
Everyone's minds explode. That's how you make a trailer. If Warner Bros. wants to make the fans happy with the first theatrical trailer, they should focus on tone and not the story. We're fast-forwarding seven or eight years, so a lot has changed. There's more than enough to catch up on just within the city of Gotham to fill a trailer. What kind of shape is Bruce Wayne in? Has he been gone all these years. The detail about the chronological jump forward is just the right note to whet appetites and keep people hooked until July.
Be sure to check out all of our updates from over the weekend on our Splash Page.
What do you want to see in the trailer? Let me know on Twitter via @KPSull, and we'll discuss next week. Also, be sure to check out our new weekly discussion show, "Talk Nerdy to Me."
Amazon.com and Wal-Mart are pushing more manufacturers to change their packaging to cut waste and ease shoppers? ?wrap rage??? the frustration felt when a product is difficult to open, Bloomberg News reports.
The nation?s largest online store and the world?s biggest retailer are asking large vendors like Procter & Gamble and headset maker Plantronics to do away with unnecessary and cumbersome packing materials, the report said.
Such awkward packaging includes hard plastic clamshell casings that enclose electronics and wire ties used to secure toys to cardboard backings, Bloomberg reported.
?We?ve gotten e-mails from customers who?ve purchased scissors in a clamshell, which would require another pair of scissors to open the package,? Nadia Shouraboura, Amazon?s vice president of global fulfillment, told Bloomberg in an interview.
Citing data from the Environmental Protection Agency, the story also notes that ?as much as a third of all consumer trash sent to landfills is estimated to be packaging,? amounting to ?more than 800 pounds of packaging waste each year per U.S. consumer.?
?The problem becomes especially acute during the holidays,? Bloomberg added, pointing to EPA data that shows from Thanksgiving to New Year?s Day, household waste in the U.S. increases by 25 percent.
Amazon launched its ?Frustration-Free Packaging? initiative in 2008.
Made a recent purchase that was mind-numbingly tough to open? What was it?
Graphene foam detects explosives, emissions better than today's gas sensorsPublic release date: 28-Nov-2011 [ | E-mail | Share ]
Contact: Michael Mullaney mullam@rpi.edu 518-276-6161 Rensselaer Polytechnic Institute
Rensselaer Polytechnic Institute engineering researchers overcome decade-old hurdle hampering development of nanostructure-based gas sensors
Troy, N.Y. A new study from Rensselaer Polytechnic Institute demonstrates how graphene foam can outperform leading commercial gas sensors in detecting potentially dangerous and explosive chemicals. The discovery opens the door for a new generation of gas sensors to be used by bomb squads, law enforcement officials, defense organizations, and in various industrial settings.
The new sensor successfully and repeatedly measured ammonia (NH3) and nitrogen dioxide (NO2) at concentrations as small as 20 parts-per-million. Made from continuous graphene nanosheets that grow into a foam-like structure about the size of a postage stamp and thickness of felt, the sensor is flexible, rugged, and finally overcomes the shortcomings that have prevented nanostructure-based gas detectors from reaching the marketplace.
Results of the study were released last week in the journal Scientific Reports, published by Nature Publishing Group. See the paper, titled "High Sensitivity Gas Detection Using a Macroscopic Three-Dimensional Graphene Foam Network," at: http://www.nature.com/srep/2011/111123/srep00166/full/srep00166.html
"We are very excited about this new discovery, which we think could lead to new commercial gas sensors," said Rensselaer Engineering Professor Nikhil Koratkar, who co-led the study along with Professor Hui-Ming Cheng at the Shenyang National Laboratory for Materials Science at the Chinese Academy of Sciences. "So far, the sensors have shown to be significantly more sensitive at detecting ammonia and nitrogen dioxide at room temperature than the commercial gas detectors on the market today."
Watch a short video of Koratkar talking about this research at: http://youtu.be/RHVW2kCr3Iw
Over the past decade researchers have shown that individual nanostructures are extremely sensitive to chemicals and different gases. To build and operate a device using an individual nanostructure for gas detection, however, has proven to be far too complex, expensive, and unreliable to be commercially viable, Koratkar said. Such an endeavor would involve creating and manipulating the position of the individual nanostructure, locating it using microscopy, using lithography to apply gold contacts, followed by other slow, costly steps. Embedded within a handheld device, such a single nanostructure can be easily damaged and rendered inoperable. Additionally, it can be challenging to "clean" the detected gas from the single nanostructure.
The new postage stamp-sized structure developed by Koratkar has all of the same attractive properties as an individual nanostructure, but is much easier to work with because of its large, macroscale size. Koratkar's collaborators at the Chinese Academy of Sciences grew graphene on a structure of nickel foam. After removing the nickel foam, what's left is a large, free-standing network of foam-like graphene. Essentially a single layer of the graphite found commonly in our pencils or the charcoal we burn on our barbeques, graphene is an atom-thick sheet of carbon atoms arranged like a nanoscale chicken-wire fence. The walls of the foam-like graphene sensor are comprised of continuous graphene sheets without any physical breaks or interfaces between the sheets.
Koartkar and his students developed the idea to use this graphene foam structure as a gas detector. As a result of exposing the graphene foam to air contaminated with trace amounts of ammonia or nitrogen dioxide, the researchers found that the gas particles stuck, or adsorbed, to the foam's surface. This change in surface chemistry has a distinct impact upon the electrical resistance of the graphene. Measuring this change in resistance is the mechanism by which the sensor can detect different gases.
Additionally, the graphene foam gas detector is very convenient to clean. By applying a ~100 milliampere current through the graphene structure, Koratkar's team was able to heat the graphene foam enough to unattach, or desorb, all of the adsorbed gas particles. This cleaning mechanism has no impact on the graphene foam's ability to detect gases, which means the detection process is fully reversible and a device based on this new technology would be low powerno need for external heaters to clean the foamand reusable.
Koratkar chose ammonia as a test gas to demonstrate the proof-of-concept for this new detector. Ammonium nitrate is present in many explosives and is known to gradually decompose and release trace amounts of ammonia. As a result, ammonia detectors are often used to test for the presence of an explosive. A toxic gas, ammonia also is used in a variety of industrial and medical processes, for which detectors are necessary to monitor for leaks.
Results of the study show the new graphene foam structure detected ammonia at 1,000 parts-per-million in 5 to 10 minutes at room temperature and atmospheric pressure. The accompanying change in the graphene's electrical resistance was about 30 percent. This compared favorably to commercially available conducting polymer sensors, which undergo a 30 percent resistance change in 5 to 10 minutes when exposed to 10,000 parts-per-million of ammonia. In the same time frame and with the same change in resistance, the graphene foam detector was 10 times as sensitive. The graphene foam detector's sensitivity is effective down to 20 parts-per-million, much lower than the commercially available devices. Additionally, many of the commercially available devices require high power consumption since they provide adequate sensitivity only at high temperatures, whereas the graphene foam detector operates at room temperature.
Koratkar's team used nitrogen dioxide as the second test gas. Different explosives including nitrocellulose gradually degrade, and are known to produce nitrogen dioxide gas as a byproduct. As a result, nitrogen dioxide also is used as a marker when testing for explosives. Additionally, nitrogen dioxide is a common pollutant found in combustion and auto emissions. Many different environmental monitoring systems feature real-time nitrogen dioxide detection.
The new graphene foam sensor detected nitrogen dioxide at 100 parts-per-million by a 10 percent resistance change in 5 to 10 minutes at room temperature and atmospheric pressure. It showed to be 10 times more sensitive than commercial conducting polymer sensors, which typically detect nitrogen dioxide at 1,000 part-per-million in the same time and with the same resistance chance at room temperature. Other nitrogen dioxide detectors available today require high power consumption and high temperatures to provide adequate sensitivity. The graphene foam sensor can detect nitrogen dioxide down to 20 parts-per-million at room temperature.
"We see this as the first practical nanostructure-based gas detector that's viable for commercialization," said Koratkar, a professor in the Department of Mechanical, Aerospace, and Nuclear Engineering at Rensselaer. "Our results show the graphene foam is able to detect ammonia and nitrogen dioxide at a concentration that is an order of magnitude lower than commercial gas detectors on the market today."
The graphene foam can be engineered to detect many different gases beyond ammonia and nitrogen dioxide, he said.
Studies have shown the electrical conductivity of an individual nanotube, nanowire, or graphene sheet is acutely sensitive to gas adsorbtion. But the small size of individual nanostructures made it costly and challenging to develop into a device, plus the structures are delicate and often don't yield consistent results.
The new graphene foam gas sensor overcomes these challenges. It is easy to handle and manipulate because of its large, macroscale size. The sensor also is flexible, rugged, and robust enough to handle wear and tear inside of a device. Plus it is fully reversible, and the results it provides are consistent and repeatable. Most important, the graphene foam is highly sensitive, thanks to its 3-D, porous structure that allows gases to easily adsorb to its huge surface area. Despite its large size, the graphene foam structure essentially functions as a single nanostructure. There are no breaks in the graphene network, which means there are no interfaces to overcome, and electrons flow freely with little resistance. This adds to the foam's sensitivity to gases.
"In a sense we have overcome the Achilles' heel of nanotechnology for chemical sensing," Koratkar said. "A single nanostructure works great, but doesn't mean much when applied in a real device in the real world. When you try to scale it up to macroscale proportions, the interfaces defeats what you're trying to accomplish, as the nanostructure's properties are dominated by interfaces. Now we're able to scale up graphene in a way that the interfaces are not present. This allows us to take advantage of the intrinsic properties of the nanostructure, yet work with a macroscopic structure that gives us repeatability, reliability, and robustness, but shows similar sensitivity to gas adsorbtion as a single nanostructure."
###
Along with Koratkar, co-authors of the paper are: Rensselaer graduate students Fazel Yavari and Abhay Varghese Thomas; along with professors W.C. Ren, H.M. Cheng and graduate student Z.P. Chen of the Shenyang National Laboratory for Materials Science at the Chinese Academy of Sciences.
This research was supported in part by the Advanced Energy Consortium (AEC), the National Science Foundation of China, and the Chinese Academy of Sciences.
For more information on Koratkar's graphene research at Rensselaer, visit:
New Graphene Discovery Boosts Oil Exploration Efforts, Could Enable Self-Powered Microsensors
http://news.rpi.edu/update.do?artcenterkey=2900
Water Could Hold Answer to Graphene Nanoelectronics
http://news.rpi.edu/update.do?artcenterkey=2783
Graphene Outperforms Carbon Nanotubes for Creating Stronger Materials
http://news.rpi.edu/update.do?artcenterkey=2715
Student Innovator Tackles Challenge of Hydrogen Storage Using Graphene
http://news.rpi.edu/update.do?artcenterkey=2690
Contact
Michael Mullaney
Rensselaer Polytechnic Institute
Troy, NY
518-276-6161
mullam@rpi.edu
http://www.rpi.edu/news
Visit the Rensselaer research and discovery blog: http://approach.rpi.edu
Follow us on Twitter: http://www.twitter.com/RPInews
[ | E-mail | Share ]
?
AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.
Graphene foam detects explosives, emissions better than today's gas sensorsPublic release date: 28-Nov-2011 [ | E-mail | Share ]
Contact: Michael Mullaney mullam@rpi.edu 518-276-6161 Rensselaer Polytechnic Institute
Rensselaer Polytechnic Institute engineering researchers overcome decade-old hurdle hampering development of nanostructure-based gas sensors
Troy, N.Y. A new study from Rensselaer Polytechnic Institute demonstrates how graphene foam can outperform leading commercial gas sensors in detecting potentially dangerous and explosive chemicals. The discovery opens the door for a new generation of gas sensors to be used by bomb squads, law enforcement officials, defense organizations, and in various industrial settings.
The new sensor successfully and repeatedly measured ammonia (NH3) and nitrogen dioxide (NO2) at concentrations as small as 20 parts-per-million. Made from continuous graphene nanosheets that grow into a foam-like structure about the size of a postage stamp and thickness of felt, the sensor is flexible, rugged, and finally overcomes the shortcomings that have prevented nanostructure-based gas detectors from reaching the marketplace.
Results of the study were released last week in the journal Scientific Reports, published by Nature Publishing Group. See the paper, titled "High Sensitivity Gas Detection Using a Macroscopic Three-Dimensional Graphene Foam Network," at: http://www.nature.com/srep/2011/111123/srep00166/full/srep00166.html
"We are very excited about this new discovery, which we think could lead to new commercial gas sensors," said Rensselaer Engineering Professor Nikhil Koratkar, who co-led the study along with Professor Hui-Ming Cheng at the Shenyang National Laboratory for Materials Science at the Chinese Academy of Sciences. "So far, the sensors have shown to be significantly more sensitive at detecting ammonia and nitrogen dioxide at room temperature than the commercial gas detectors on the market today."
Watch a short video of Koratkar talking about this research at: http://youtu.be/RHVW2kCr3Iw
Over the past decade researchers have shown that individual nanostructures are extremely sensitive to chemicals and different gases. To build and operate a device using an individual nanostructure for gas detection, however, has proven to be far too complex, expensive, and unreliable to be commercially viable, Koratkar said. Such an endeavor would involve creating and manipulating the position of the individual nanostructure, locating it using microscopy, using lithography to apply gold contacts, followed by other slow, costly steps. Embedded within a handheld device, such a single nanostructure can be easily damaged and rendered inoperable. Additionally, it can be challenging to "clean" the detected gas from the single nanostructure.
The new postage stamp-sized structure developed by Koratkar has all of the same attractive properties as an individual nanostructure, but is much easier to work with because of its large, macroscale size. Koratkar's collaborators at the Chinese Academy of Sciences grew graphene on a structure of nickel foam. After removing the nickel foam, what's left is a large, free-standing network of foam-like graphene. Essentially a single layer of the graphite found commonly in our pencils or the charcoal we burn on our barbeques, graphene is an atom-thick sheet of carbon atoms arranged like a nanoscale chicken-wire fence. The walls of the foam-like graphene sensor are comprised of continuous graphene sheets without any physical breaks or interfaces between the sheets.
Koartkar and his students developed the idea to use this graphene foam structure as a gas detector. As a result of exposing the graphene foam to air contaminated with trace amounts of ammonia or nitrogen dioxide, the researchers found that the gas particles stuck, or adsorbed, to the foam's surface. This change in surface chemistry has a distinct impact upon the electrical resistance of the graphene. Measuring this change in resistance is the mechanism by which the sensor can detect different gases.
Additionally, the graphene foam gas detector is very convenient to clean. By applying a ~100 milliampere current through the graphene structure, Koratkar's team was able to heat the graphene foam enough to unattach, or desorb, all of the adsorbed gas particles. This cleaning mechanism has no impact on the graphene foam's ability to detect gases, which means the detection process is fully reversible and a device based on this new technology would be low powerno need for external heaters to clean the foamand reusable.
Koratkar chose ammonia as a test gas to demonstrate the proof-of-concept for this new detector. Ammonium nitrate is present in many explosives and is known to gradually decompose and release trace amounts of ammonia. As a result, ammonia detectors are often used to test for the presence of an explosive. A toxic gas, ammonia also is used in a variety of industrial and medical processes, for which detectors are necessary to monitor for leaks.
Results of the study show the new graphene foam structure detected ammonia at 1,000 parts-per-million in 5 to 10 minutes at room temperature and atmospheric pressure. The accompanying change in the graphene's electrical resistance was about 30 percent. This compared favorably to commercially available conducting polymer sensors, which undergo a 30 percent resistance change in 5 to 10 minutes when exposed to 10,000 parts-per-million of ammonia. In the same time frame and with the same change in resistance, the graphene foam detector was 10 times as sensitive. The graphene foam detector's sensitivity is effective down to 20 parts-per-million, much lower than the commercially available devices. Additionally, many of the commercially available devices require high power consumption since they provide adequate sensitivity only at high temperatures, whereas the graphene foam detector operates at room temperature.
Koratkar's team used nitrogen dioxide as the second test gas. Different explosives including nitrocellulose gradually degrade, and are known to produce nitrogen dioxide gas as a byproduct. As a result, nitrogen dioxide also is used as a marker when testing for explosives. Additionally, nitrogen dioxide is a common pollutant found in combustion and auto emissions. Many different environmental monitoring systems feature real-time nitrogen dioxide detection.
The new graphene foam sensor detected nitrogen dioxide at 100 parts-per-million by a 10 percent resistance change in 5 to 10 minutes at room temperature and atmospheric pressure. It showed to be 10 times more sensitive than commercial conducting polymer sensors, which typically detect nitrogen dioxide at 1,000 part-per-million in the same time and with the same resistance chance at room temperature. Other nitrogen dioxide detectors available today require high power consumption and high temperatures to provide adequate sensitivity. The graphene foam sensor can detect nitrogen dioxide down to 20 parts-per-million at room temperature.
"We see this as the first practical nanostructure-based gas detector that's viable for commercialization," said Koratkar, a professor in the Department of Mechanical, Aerospace, and Nuclear Engineering at Rensselaer. "Our results show the graphene foam is able to detect ammonia and nitrogen dioxide at a concentration that is an order of magnitude lower than commercial gas detectors on the market today."
The graphene foam can be engineered to detect many different gases beyond ammonia and nitrogen dioxide, he said.
Studies have shown the electrical conductivity of an individual nanotube, nanowire, or graphene sheet is acutely sensitive to gas adsorbtion. But the small size of individual nanostructures made it costly and challenging to develop into a device, plus the structures are delicate and often don't yield consistent results.
The new graphene foam gas sensor overcomes these challenges. It is easy to handle and manipulate because of its large, macroscale size. The sensor also is flexible, rugged, and robust enough to handle wear and tear inside of a device. Plus it is fully reversible, and the results it provides are consistent and repeatable. Most important, the graphene foam is highly sensitive, thanks to its 3-D, porous structure that allows gases to easily adsorb to its huge surface area. Despite its large size, the graphene foam structure essentially functions as a single nanostructure. There are no breaks in the graphene network, which means there are no interfaces to overcome, and electrons flow freely with little resistance. This adds to the foam's sensitivity to gases.
"In a sense we have overcome the Achilles' heel of nanotechnology for chemical sensing," Koratkar said. "A single nanostructure works great, but doesn't mean much when applied in a real device in the real world. When you try to scale it up to macroscale proportions, the interfaces defeats what you're trying to accomplish, as the nanostructure's properties are dominated by interfaces. Now we're able to scale up graphene in a way that the interfaces are not present. This allows us to take advantage of the intrinsic properties of the nanostructure, yet work with a macroscopic structure that gives us repeatability, reliability, and robustness, but shows similar sensitivity to gas adsorbtion as a single nanostructure."
###
Along with Koratkar, co-authors of the paper are: Rensselaer graduate students Fazel Yavari and Abhay Varghese Thomas; along with professors W.C. Ren, H.M. Cheng and graduate student Z.P. Chen of the Shenyang National Laboratory for Materials Science at the Chinese Academy of Sciences.
This research was supported in part by the Advanced Energy Consortium (AEC), the National Science Foundation of China, and the Chinese Academy of Sciences.
For more information on Koratkar's graphene research at Rensselaer, visit:
New Graphene Discovery Boosts Oil Exploration Efforts, Could Enable Self-Powered Microsensors
http://news.rpi.edu/update.do?artcenterkey=2900
Water Could Hold Answer to Graphene Nanoelectronics
http://news.rpi.edu/update.do?artcenterkey=2783
Graphene Outperforms Carbon Nanotubes for Creating Stronger Materials
http://news.rpi.edu/update.do?artcenterkey=2715
Student Innovator Tackles Challenge of Hydrogen Storage Using Graphene
http://news.rpi.edu/update.do?artcenterkey=2690
Contact
Michael Mullaney
Rensselaer Polytechnic Institute
Troy, NY
518-276-6161
mullam@rpi.edu
http://www.rpi.edu/news
Visit the Rensselaer research and discovery blog: http://approach.rpi.edu
Follow us on Twitter: http://www.twitter.com/RPInews
[ | E-mail | Share ]
?
AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.
>>following big breaking news on
herman cain
. he told a senior staff he is reassessing his campaign for president after ginger white went public with her alleged 13-year affair with
herman cain
. according to
cain
's iowa chairman, he addressed all the national staff in a 10-minute
conference call
and reiterated this was a friend and he was trying to help her out financially and nothing inappropriate happened.
cain
emphasized the campaign was continuing on and he would deliver a planned speech in michigan tonight and he was
looking forward
to it. he said it has taken an emotional toll on his family and that's difficult for them.
john harwood
joins us live now. what do you think? what might be
herman cain
's next mess. what does reassessing mean?
>>he has to figure out whether or not it's worth it given that his poll numbers have been going down because of the previous allegations are likely to continue going down. he said yesterday on cnn he would stay in the race as long as his wife was behind him. you got to wonder whether or not in light of the latest allegations whether she decided she had enough of this whole enterprise. i can tell you that many others are thinking of
cain
and supporters in the
past tense
in terms of a
cain
set of supporters and looking for how they can take advantage of the situation to pick up the support.
>>is
cain
on the same page? you have the information coming in about him telling the folks there that this woman was a friend and he was helping her out financially. the guy in charge of his iowa team said in a tweet overnight referring to this woman as a stalking defaming liabler in a tweet about her. you would think that
herman cain
would pull these people back a little bit. he know what is went on more than anybody else more than ginger white.
>>the fact that the team
cain
was not on the same page was evident when he went on cnn and dressed the charges and said no affair and no sex and nothing like that. his attorney put out a statement saying nobody should ask the questions. you have the tweet going after her really hard. clearly they have been knocked back by this and they are not sure how to proceed.
herman cain
is trying to figure out whether it's worth it to keep going. we will see if he delivers that speech, but he is in a very, very difficult position. i think his chances of getting this nomination if they were ever significant are way diminished if not nonexistent.
>>let's bring in the political panel and
talk show host
,
michael smerconish
and an msnbc contributor. thank you, gentlemen. we will start with you, michael. a lot of people speculated that the only reason
herman cain
got in the race was to sell books and get out there and get his face in there. now he stepped in political
quick sand
.
>>this may have been how it all began, but he caught the wave that we discover and started to believe he could win this bring, meaning at least the nomination. the handwriting was already on the wall that he was in decline and this is going to finish him off. what i find most significant is the statement to the media that said this is the case of alleged consensual sex or a relationship on the part of these two people. therefore it's a private matter. i think he's right when he makes that argument but because of the harassment charges, people will never give that break.
>>you are interest to pose that question. that's the gut check we will ask people if they think it should matter. what is interesting is that you have conservative who is defended
herman cain
in the accusations that he harassed women and forced one woman's head into his lap. they are abandoning him in the wake of an affair.
sean hannity
who was a booster and on fox news, governor
mike huckabee
saying that he thinks this is the most damagingly allegation to date. not the
sexual harassment
, but that he may have cheated on his wife.
>>i see it in the reverse order. i think harassment is a far more serious charge to be levelled against a public servant. if there were no allegations of harassment and this guy cheated on his wife and it was a case of infidelity and i'm not minimizing it, this is a matter for he and his wife and it's not our business.
>>let me bring you in on this. i love this headline for many reasons. you said the most famous phi landerer is gaining a windfall. he could reap the benefits. not that i need you to help me, but to the audience here.
>>we have seen a pattern prevail in the race going like this. there is about 30 or 40 or maybe more percent that just doesn't want to get behind
mitt romney
. it was
michele bachmann
and then
herman cain
and
rick perry
.
donald trump
when he was pretending to run. the numbers have evaporated. instead of any of that support going to romney, it found a new non-romney choice. already
herman cain
was sliding back in the polls and already going to
newt gingrich
who got to the low 20s. if you look at the poll break down and the
cain
supporters and said do you have a favorable opinion of
newt gingrich
, they say yes. 35% say yes about
mitt romney
. they like
newt gingrich
. he is surging. i think this is now a case where next week,
newt gingrich
will be 10 or 15 points ahead of
mitt romney
.
>>regarding
herman cain
's situation, i think it's a difficult situation for he and his family. i hope he reaches whatever the right decision is for them. beyond that i won't have any comment. that's safe.
>>it's a school of thought that said adultery is in the news and it will remind them and hurt them too.
>>that's what you think.
>>he is talking to the
social conservative
leaders and they don't top the get behind
mitt romney
.
newt gingrich
is giving them the path.
>>we are christians and we forgive.
>>i have a wife now and what's in the past is in the past.
>>you have
mitt romney
in
florida
, the first candidate to plant his flag in that state for not just republicans and democrats as well and nobody is talking about that.
>>it will be a long haul and we will talk about
florida
. we will continue to see a knockout blow and he can strike in warks and new hampshire. they are not looking at how the rules have changed in this season and the reality is we no longer play by winner take all. they will focus on
florida
and beyond into super tuesday.
>>we have our attention on
mitt romney
when others fallout for whatever reason. may it be scandal or cannot survive financially.
>>could be for sure. i think it's like a game of roulette where the ball is bouncing at the end. has it stopped bouncing? i don't think it stopped bouncing on the
newt gingrich
number. there is more play to come.
I get asked a lot why Instagram is so popular. It might be because we just threw the first iPhone photography conference,?1197, or because I?allegedly?run?a company?that studies and designs interfaces. It could also be the world of photography is changing so fast that lots of us nerds are ?talking about how a tool like Instagram can pass?10 million users in 355 days. The interface implications are fascinating, the company and technology dynamics of serving content to 10 million users with less than ten employees are fascinating, the artistic content is fascinating, and the reasons why people like me are so?addicted?to the damn thing are fascinating. Here's a crack at why, since I think some other attempts haven't quite captured it.
PARIS?? The United States and others must "be prepared to face the worst" as Europe slides toward another recession, according to a gloomy warning from the Organization for Economic Cooperation and Development.
Failure by EU leaders to stem the debt crisis that has spread from Greece to much-bigger Italy "could massively escalate economic disruption" and end in "highly devastating outcomes," the Paris-based OECD said in its latest bi-annual economic forecast on Monday.
Improved global prospects would also depend on the enactment of a credible medium-term fiscal program in the United States, it said.
"The global economy is not out of the woods," the report said.
It added that even the U.S. was at risk of returning to recession if "no action [was] agreed to offset the large degree of fiscal tightening implied by current law."
"This could tip the economy into a recession that monetary policy could do little to counter," it said.
It predicted Britain will slip back into a modest recession early next year, threatening to derail deep austerity measures there.
Story: Timothy Geithner, Barack Obama ramp up pressure on Europe over economic crisis
It also recommended an urgent boost top the EU bailout fund and called on Europe's central bank to do more to stem the crisis.
Global gloom
The OECD report was the latest in a series of increasingly gloomy forecasts, and comes as China's economy is slowing and Japan's exports are tumbling.
Eastern European countries are wobbling as credit dries up from a pullback in lending by eurozone banks.
In the United States, the improving economic picture has clouded somewhat after a mixed batch of economic data and downward revision to third-quarter growth to 2.0 percent doused some of the optimism for a strong fourth quarter. Consumer spending slowed in October and business investment weakened, showing a recovery that remains weak and vulnerable to shocks.
Against this uncertain backdrop, financial markets are volatile as European leaders fail to deliver any credible solutions to the sovereign debt crisis and U.S. lawmakers hit gridlock on slashing the budget deficit, further eroding business and consumer confidence and damaging growth prospects.
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The U.S. labor market epitomizes these problems.
Two years into a recovery in which corporate profits are robust, hiring should be rebounding sharply. But U.S. employment numbers due on Friday are expected to show an economy treading water, with 120,000 new hires in November, up from 80,000 the prior month but way below the level needed to improve the outlook.
"The trend has been fairly stable over the last five months, stuck at a level just about strong enough to absorb new entrants into the labor force, but not to reduce the unemployment rate significantly," said Jeoff Hall, economist at IFR Markets, a Thomson Reuters company.
In fact, large U.S. companies are showing new caution.
Boeing Co announced plans last week to shutter a Kansas factory that employs 2,100 as it prepares for U.S. federal budget cuts that will hit defense spending hard. Bank of America began sending lay-off notices last week to technology staff as part of plans to cut 30,000 positions over the next few years, and Wells Fargo & Co also began job cuts.
Whirlpool Corp, the world's largest maker of household appliances, reports softening demand worldwide, including fast-growing emerging Asia and Latin America, and is cutting about 5,000 jobs in North America and Europe.
Srinivas Thiruvadanthai, director of research at the Jerome Levy Forecasting Center, also is concerned that fiscal tightening in the United States ? from the roll-off of 2009 stimulus projects, cutbacks to city and state budgets and possible expiration of the payroll tax cut ? will further weaken the U.S. consumer, who accounts for the bulk of growth.
"Clearly Europe is in bad shape, and the global economic conditions are worsening too. If the U.S. consumer tires, the chances for recession are met," he said.
Since late September, the Levy Center has forecast that Europe's debt crisis will hit the United States through financial markets, its banks, weakened exports, lowered corporate profits and drag the United States into recession in 2012. Thiruvadanthai sees nothing to alter that picture.
European mess
European finance ministers meet again on Tuesday to review strengthening the region's bailout fund, seen only a month ago as the centerpiece for halting its debt crisis. But the sharp deterioration in eurozone debt prices, which sucked in Germany last week in a failed bund auction, has undercut how much the fund can be leveraged, leaving investors highly skeptical that politicians can use it to stem contagion.
Italy issues 8 billion euros in longer term debt on Tuesday. Two-year Italian paper already is priced a 8 percent, one full point above the yield considered affordable by a nation with a stalled economy. Belgium, downgraded from AA-plus to AA by S&P on Friday, raises cash a day earlier, with the cost of insuring its debt having hit a record level.
Goldman Sachs warned on Friday that the public sector funding problems, which are hurting bank profits, are restricting household and corporate credit in Europe. This "could turn the moderate recession we are forecasting into something more akin to the 2008/09 experience."
Ripples from the slowdown are felt as far away as Brazil. Its central bank is expected to lower interest rates on Wednesday for third time since August, by a hefty 50 basis points, to 11 percent.
For the United States, recession remains a minority view, though forecasts are being revised downward for 2012. The Institute of International Finance, for instance, noted near-term resilience in its latest forecast but storm clouds ahead.
As long as European leaders delay in delivering a fiscal union that can rescue the common currency, financial markets will remain in the driving seat and the growth picture shaky.
"The world is struggling along, with downside risks from a bust-up of the eurozone, or Greece, Italy and Spain leaving. It might be that Europe just runs out of time to fix its problems," said Paul Ashworth, economist at Capital Economics.
Reuters and msnbc.com staff contributed to this report
WASHINGTON ? The White House says President Barack Obama considers the death of 24 Pakistani troops in a cross-border fight involving NATO forces a tragedy and says the administration is determined to look into the circumstances of the air strikes.
White House spokesman Jay Carney says the president extends sympathy to the families of the dead soldiers and to the people of Pakistan in general. Carney said: "We take it very seriously."
The incident has deepened tensions between the United States and Pakistan, a country that has been essential to the U.S. in its effort to combat al-Qaida and the Taliban. Carney called the relationship with Pakistan complicated, but said it is important to maintain a cooperative relationship with Pakistan.
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Public release date: 28-Nov-2011
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I get asked a lot why Instagram is so popular. It might be because we just threw the first iPhone photography conference,?
