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Minggu, 16 Mei 2010

Bionic Arm Moved by Thought

A young woman who lost an arm at the shoulder in a motorcycle accident is using a computer-controlled, electric-powered arm to do almost everything her own arm could do.

It used to be that you could only find the bionic man or woman in science fiction. Biomedical engineers are changing that. Listen to the podcast.

If you wanted to see bionic arms or legs in action, you used to have to look back to 1970s television shows or Star Wars movies. Now, those fantasies are moving off the screen and into real life.

Claudia Mitchel lost her arm at the shoulder in a motorcycle accident, and is now using a computer-controlled, electric-powered arm to do almost everything her biological arm could do. Peel and eat a piece of fruit. Fold clothes. Even wash the dishes. And maybe best of all, all she has to do is think about what she wants to do, and it happens.

It works like this. Doctors moved the ends of the nerves that used to connect to her mangled arm to her chest. Electrodes on a harness detect tiny electric signals from those nerves and transmit them to a miniature computer. The computer translates them into signals that control small electric motors in her new arm and hand. When she wants to pick up an apple from the kitchen table, she thinks it and her arm, hand and fingers do it.

One problem: the arm and hand have no sense of touch. But everything else seems to be working fine.

Our arm isn’t computer controlled, but it’s still time to close the mike and leave.



Recomend link:
http://news.discovery.com/videos/tech-man-controls-robotic-hand-with-mind.html

Rabu, 12 Mei 2010

Electronic Waste Produces Algae for Biofuel (A different way to recycle old computers)





THE GIST

* Old computer parts serve as a reservoir to cultivate algae.
* The algae can be used to make biodiesel.
* If just 6.5 percent of Americans had one, we could replace petroleum with biodiesel.

When you think of recycling electronics, no doubt you imagine the old PC or mobile phone being disassembled, and it’s metal and plastic parts melted down to be repurposed. But for some people, it means reusing the parts to grow algae.

Students at the University of Illinois at Urbana-Champaign created Bio-Grow, a device made from various computer parts that serves as a reservoir to cultivate algae.

The algae can then be used in biodiesel production, which could potentially replace petroleum in the futures.

“If someone had one of these in their homes, they would cultivate algae and extract it,” said team member and undergraduate student Megan Kenney. “Then they could take it into a gas company that was set up with an oil filtration facility and get credit off their gas.”

Kenney, along with undergraduate students Timothy Harvey, Elliot Reese and Mark Schnitzer, and graduate student Saeidreza Shiftehfar was focused on finding a way to be green, and ended up winning second place in the International Electronic Waste Competition at the University of Illinois at Urbana-Champaign with their design.

“The whole point of our project was two different concepts,” Schnitzer said. “To use electronic waste and to solve a green issue in the world.”

Which is why the team chose to use old electronics to build the device called an algae bioreactor. It encourages photosynthesis, the chemical reaction that happens in plants, which uses sunlight to convert carbon dioxide into sugar.

“By using e-waste, you are giving a second life to all these electronics,” Kenney said.

The algae-growing tank was made from the side panels of an Apple G4 CPU tower, with PVC pipes and acrylic panels for structural support. The team used an Apple iMac CRT to emit the light and heat the algae needs to grow. The entire structure had to be sealed and housed within an outer cowell made of high-density foam, which provides stability as well as insulation.

A modified Dell Latitude CPX laptop was programmed to monitor and control the iMac CRT so that it would turn on a specific light spectrum at different intervals of time and adjust the temperature within the tank.

“Algae’s best growth factors are within the red and blue spectrums of light at a ratio of four to one,” Kenney said. “We also knew that it needed to be 62 to 82 degrees.”

The tank also has a water pump, which aerates the algae and provides it with the maximum exposure to sunlight. A faucet allows the user to extract the algae.

The process of creating biofuel from algae is complex and expensive and to date remains in research labs. But the team hopes this project will bring biofuel down to the household level, which would drive up production and lower costs.

“We are imagining this product will eventually become part of a larger system,” Harvey said. “You won’t just have it in your house, you would take the algae to a biomass collection point, at which point it would be transported to a refinery.”

The refinery would then extract the lipids from the algae, which is up to 50 percent of the algae’s components to create biodiesel. The byproducts can be used for feedstock, fertilizer and high-end pharmaceuticals because algae is so rich in protein and nutrients.

The teams’ calculations showed that if just 6.5 percent of Americans had one of these in their homes, it could generate the amount of algae needed to replace petroleum with biodiesel.

And algae growers would make money, too. Kenney said the algae could be sold for a dollar a gallon, and because algae grows so fast, it could be harvested every three days.

If this device becomes commonplace like the team is hoping, perhaps the vases that adorn end tables in homes across the nation will be replaced by an algae-growing tank which could produce gas for the cars of the future.



Specific link: http://news.discovery.com/tech/electronic-waste-grows-algae.html

Sabtu, 24 April 2010

Mars Pathfinder Fact Sheet




Entry Descent Landing (EDL)

Interplanetary Trajectory

Mission Summary

Artist's Concept Of Lander And Microrover On Mars

The Mars Pathfinder Mission is the second launch in the Discovery Program, a NASA initiative for planetary missions with a maximum three year development cycle and a cost cap of $150M (FY92) for development. The Mars Pathfinder is managed for NASA by the Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California.

The mission is primarily an engineering demonstration of key technologies and concepts for eventual use in future missions to Mars employing scientific landers. Pathfinder also delivers science instruments to the surface of Mars to investigate the structure of the martian atmosphere, surface meteorology, surface geology, form, and structure, and the elemental composition of martian rocks and soil. In addition a free-ranging surface rover is deployed to conduct technology experiments and to serve as an instrument deployment mechanism.

Mission Description

The flight system is launched on a Delta II-7925 launch vehicle which includes a payload assist module (PAM)-D upper stage, from the Cape Canaveral Air Station. The mission launch window is a 29-day period beginning on December 2, 1996.

After launch, the spacecraft requires 6 to 7 months to reach Mars, depending upon the exact launch date. During this phase, a series of four trajectory correction maneuvers (TCMs) are performed, in order to fine tune the flight path. Tracking, telemetry, and command operations with the spacecraft are conducted using the giant dish antennas of the NASA/JPL Deep Space Network (DSN). Upon arrival at Mars on July 4, 1997, the spacecraft will enter the martian atmosphere, and then deploy the parachute, rocket braking system, and air bag system for a soft, upright landing. At this point the primary data-taking phase begins, and continues for 30 martian days or sols (24.6 hours).

During this time, the microrover is deployed and operated for at least 7 sols. If the lander and rover continue to perform well at the end of this period, an extended mission may continue for up to one martian year for the lander, and the microrover for up to 30 sols.

Major Mission Characteristics

Launch Period
December 2 - 31, 1996
Launch Vehicle
Delta II - 7925
Trajectory
6-7 Months
Primary Mission
Land On Mars - July 4, 1997
Complete Surface Mission
August 1997
End Of Project
September 1998



For more information: http://marsprogram.jpl.nasa.gov