Saturday, 27 March 2010

Johnald's Fantastical Daily Link Splurge

Johnald's Fantastical Daily Link Splurge

New RFID Tag Could Mean the End of Bar Codes

Posted: 26 Mar 2010 03:11 PM PDT


Lines at the grocery store might become as obsolete as milkmen, if a new tag that seeks to replace bar codes becomes commonplace.

sciencenewsResearchers from Sunchon National University in Suncheon, South Korea, and Rice University in Houston have built a radio frequency identification tag that can be printed directly onto cereal boxes and potato chip bags. The tag uses ink laced with carbon nanotubes to print electronics on paper or plastic that could instantly transmit information about a cart full of groceries.

"You could run your cart by a detector and it tells you instantly what's in the cart," says James M. Tour of Rice University, whose research group invented the ink. "No more lines, you just walk out with your stuff."

RFID tags are already used widely in passports, library books and gadgets that let cars fly through tollbooths without cash. But those tags are made from silicon, which is more expensive than paper and has to be stuck onto the product as a second step.

"It's potentially much cheaper, printing it as part of the package," Tour says.

The new tag, reported in the March issue of IEEE Transactions on Electron Devices, costs about three cents to print, compared to about 50 cents for each silicon-based tag. The team hopes to eventually bring that cost below one cent per tag to make the devices commercially competitive. It can store one bit of information — essentially a 1 or a 0 — in an area about the size of a business card.

That's not much compared to computer chips, but Tour says this tag is just a "proof of concept." Study coauthor Gyoujin Cho of Sunchon National University, along with a team from the Printed Electronics Research Center of the Paru Corporation in Suncheon, Korea, are working to pack more transistors into a smaller area to ultimately squeeze 96 bits onto a 3-square-centimeter tag. That would be enough to give a unique identification code to each item in a supermarket, along with information like how long the item has been on the shelf, Tour says.

The tags were made possible by the creation of semiconducting ink, which contains carbon nanotubes that will hold an electrical charge. A transistor needs to be completely semiconducting to hold information, Tour says. If there are any bits of conducting metal — which moves electric charges around easily — mixed in, the information-holding charge will leak out quickly.

The mixture of nanotubes created in Tour's lab includes both semiconducting nanotubes and conducting nanotubes. Separating out the conducting nanotubes is "a horrid experience," Tour says. "They're very painful to separate." So instead, the team devised a way to coat the conducting nanotubes in a polymer to protect the electric charge and allow the ink to be purely semiconducting.

Once they had the ink, Cho and his colleagues built roll printers to transfer ink to the final material. The tags are printed in three layers, and one of the remaining hurdles to making the tags store more memory in less space is to improve the alignment of those layers, Cho says.

"The work is impressive," comments Thomas N. Jackson of Penn State University in University Park, who is also developing flexible electronics. He thinks it will be difficult to compete with silicon, which is well established in the realm of consumer products packaging. But similar technology could be used to do things silicon can't do, he says, such as make smart bandages that can sense infections or freshness-sensing food packaging.

And for those who would rather not have their food broadcast radio waves after getting it home, fear not. Tour says the signals can be blocked by wrapping groceries in aluminum foil.

What’s It Like to Fly the Space Shuttle? We Find Out

Posted: 26 Mar 2010 12:27 PM PDT


As a person who really enjoys flying airplanes, I never thought I would ever say this, but flying a simulator can be as much fun as flying the real thing. Of course it helps when the simulator is a replica of the space shuttle cockpit at the Johnson Space Center in Houston.

On a recent assignment for AOPA Pilot magazine, I arrived early for an interview with Ken Ham, commander on the shuttle flight scheduled to lift off on May 14. While I waited, an engineer fired up the simulator where we were going to conduct the interview and let me make some practice approaches.

Known as the Shuttle Engineering Simulator, or SES, it's not the full motion simulator used for full flight profile training, but rather a fixed-base simulator used by astronauts and engineers for both training and testing changes that will be made on the shuttle. The SES is very similar to the e-cab used by Boeing and other aircraft makers to test systems before putting them on the real thing.

Whether it was a change to a guidance computer, or an upgrade to the software controlling the nine glass panel displays, many of the improvements made to the shuttle over the years were tested right here. Shuttle commanders and pilots (commander is in left seat, pilot in the right) also use the SES for training, especially early on in their preparation.

The wood on the floor in front of left seat has been worn smooth by thousands of heels sliding back and forth controlling the rudder pedals over the years. With the news that the shuttle will likely continue flying into 2011, instead of being retired later this year as previously scheduled, the SES may yet see a few more heels.

Sadly, even with the extension, this was as close as I would probably get to my astronaut dreams. Still I was eager to try flying the heaviest and most expensive glider ever built.

Primary flight display passing through 33,000 feet

Primary flight display passing through 33,000 feet

Computers control much of the flight until the last 4-5 minutes before landing. So I was given the chance to fly several approaches into the Kennedy Space Center, landing on runway 15. My flights began with the shuttle heading east towards the Atlantic passing over KSC at 50,000 feet and 240 knots (equivalent air speed or KEAS).

It turns out the shuttle is a terrible glider. I don't have a lot of glider experience, but I know that pitching nose down at 20 degrees and a descent rate of around 10,000 feet per minute isn't considered good. An airliner typically follows a 3-degree glide path when approaching the runway. According to Commander Ham, this is probably the biggest challenge facing the average pilot.

"The sight picture is a lot different," he said, "but it's a pretty easy task for an experienced pilot to make a safe landing," Commander Ham said, adding that a perfect landing is very difficult.

Of course, like many things, it might be easy when everything is going right. It's the emergencies and unexpected scenarios that require the bulk of the training.

"Then things get a bit more difficult. It starts to challenge your flying skills a bit more," Commander Ham noted, saying it is similar to flying other aircraft where you train for emergencies. "It's just another flying job."

I paused and debated to myself whether or not to challenge that last point. Never mind.

Back in the sim, I passed through 40,000 feet and got ready to start my turn around the heading alignment cone or HAC, which is a guidance system that allows pilots to follow a circular descent path to the runway. As I continued the turn, I could see the Florida coast out the left window, and out of habit, I started looking for the runway.

The view from left seat inside the SES

The view from left seat inside the SES

My airspeed was around 290 knots as I turned to line up with runway 15 and pass through 12,000 feet. The shuttle is remarkably stable to fly as I suppose would be the case with any brick featuring stubby wings. Moving the stick is a bit unusual because it requires only small wrist movements.

Perhaps most interesting is that it pivots in the middle of the palm for pitch (controlling nose up or nose down). Commander Ham explained later that this is to prevent inadvertent movement during launch. "It's a beautiful design, you can fly uphill at 3g's with your hand on the stick and nothing happens," he said.

So far the approach hadn't been too difficult. In front of me there was a heads-up display (HUD) with airspeed, altitude and other key flight parameters. Most importantly there was a flight-path marker and guidance diamond. These navigation aids make it rather easy for a pilot to find the way to the runway and line up, assuming that everything is working. You just keep the flight-path marker on the guidance diamond and the runway should eventually appear in front of you.

On final approach, a pair of triangles rose from the bottom of the HUD when it was time to begin the flare, which slows the rate of descent. In a typical small airplane, a pilot might begin the flare at 10 to 30 feet above the runway traveling around 60 knots. In the shuttle, you start the flare at 2,000 feet and 300 knots. That part would take some getting used to.

"This is the critical part," Commander Ham explained. "At 2,000 feet, if you don't start pulling up, you're going to die."

So I followed the guidance on the HUD and touched down the main gear with a squeak at 200 knots with the nose still pointing rather high in the air. After what seeemed like a very long time, the nose gear eventually came down with a thud and I rolled safely to a stop.

A space shuttle commander has countless landings in simulators at the Johnson Space Center, and at least a thousand simulated landings in NASA's Shuttle Training Aircraft. I realize I'm a long way from having the skills necessary to fly the orbiter. But if I were ever stowed away in the cargo bay and the announcement came over the speakers, "Is there a pilot on board?" I would at least have a chance of getting the world's heaviest glider on the ground safely.

Images: Jason Paur/

Lab-Quality Booze Detector Fits in a Suitcase

Posted: 26 Mar 2010 11:46 AM PDT


Ever found yourself staring down a punch bowl at a frat party and wondering just how spiked it might be?

What you needed was the AlcoQuick 4000, a briefcase-sized infrared spectrometer that can accurately determine the alcohol content of a wide variety of beverages in just 60 seconds, according to a new study in the open source journal Chemistry Central.

alcoquickFor every day use, you can use an alcoholmeter, first developed by Gay-Lussac in the 1820s. It's essentially a tube that you can insert into a liquid-containing beaker that uses the difference in density between water and alcohol to determine how much alcohol is in the beverage.

But some people, notably scientists and tax collectors, need more precise readings of alcohol content. They use complex techniques that require the liquid in question to be distilled. That limits the diffusion of the techniques and can prove downright impractical in some settings.

The German researchers who conducted the study say that the AlcoQuick could be especially useful in analyzing "unrecorded alcohol," which you might know as "moonshine." They estimate that one-quarter of the world's alcohol consumption comes in this form, largely in developing countries without strong regulatory regimes.

"In this context, expensive laboratory measurements such as distillation and pycnometry are not practical, but portable, battery-powered infrared sensors offer a feasible alternative in areas of lower socioeconomic status," they conclude.

So, watch out Bangladesh, your days of moonshining could be coming to a technology-induced end soon.

Citation: "Rapid and mobile determination of alcoholic strength in wine, beer and spirits using a flow-through infrared sensor" by Dirk W Lachenmeier, Rolf Godelmann, Markus Steiner, Bob Ansay, Jurgen Weigel, and Gunther Krieg. doi:10.1186/1752-153X-4-5

Image: hoggarazzi/Flickr

WiSci 2.0: Alexis Madrigal's Twitter, Tumblr, and green tech history research site; Wired Science on Twitter and Facebook.

Ron Howard Was Wrong: Apollo 13 Would Have Burned, Not Frozen

Posted: 26 Mar 2010 10:33 AM PDT

The Apollo 13 module, had it not been for NASA's heroic efforts to get it back on course, would have missed Earth and tumbled into the depths of cold, lonely space.

At least that's been the story repeated in popular, academic, and cinematic accounts of the ill-fated mission, like Ron Howard's Apollo 13.

Now, space writer Andrew Chaikin and a team of modelers at Analytical Graphics have stumbled upon a surprise: The official story isn't true. Instead of drifting into a nearly eternal orbit around Earth, the ship would have swung out past the moon, been pushed by its gravitational field, and been sent hurtling back toward Earth on a collision path, as described in the video above.

In any case, the crew would not have survived. They'd have frozen first, then burned up on re-entry.

Luckily, James Lovell, Jack Swigert and Fred Haise were able to use the lunar module as a lifeboat and make it safely home with the help of Ed Harris, er, Eugene F. Kranz, the flight director for the mission.

And while we're debunking Apollo 13 myths, the astronauts never actually said, "Houston, we have a problem." They said, "Houston, we've had a problem."

And if you ever correct someone on the presence of that helping verb at a party, you join an elite club of pedants who love space and grammar too much. Contact us immediately with a YouTube video of the incident and we'll send you a pin, because it's our club.


Via CollectSPACE

Image: The damage caused by the oxygen explosion that nearly cost the Apollo 13 astronauts their lives/NASA.

WiSci 2.0: Alexis Madrigal's Twitter, Tumblr, and green tech history research site; Wired Science on Twitter and Facebook.