Daily Archives: October 8, 2009
Dow’s POWERHOUSE solar shingles get along with non-solar siblings, your HOA
Massive photovoltaic installations on rooftops are nothing terribly new, but by and large, the ones we’ve seen are stuck on massive warehouses or elaborate stadiums in foreign lands. Dow Chemical is doing its darnedest to change all that with the introduction of the POWERHOUSE line of solar shingles. As you’d expect, these solar shingles are aimed at roofers looking to tip their hats to Ma Earth while providing shelter for well-endowed homeowners, and unlike most of the futuristic alternatives, these actually look somewhat similar to traditional shingles. Dow claims that “affordability” will be a feature when they become widely available in 2011, but we’re understandably skeptical of such a claim given just how pricey solar roofs currently are (and you know, considering the company’s for-profit standing).
[Via Jetson Green]
http://www.engadget.com/2009/10/08/dows-powerhouse-solar-shingles-get-along-with-non-solar-sibling/
IBM’s ultra-cheap DNA Transistor dream could lead to personalized medicines, confusion
Are you ready to get your nerd on? No, seriously — are your rimmed glasses and pressed slacks at the ready? Good. IBM has just announced a full-on research project that intends to drive the cost of DNA sequencing down from millions of dollars to under $1,000. The reason? An ultra-cheap, silicon-based DNA Transistor could essentially “pave the way to read human DNA easily and quickly, generating advancements in health condition diagnosis and treatment.” Moreover, it could eventually lead to personalized genome analysis and personalized medicines, meaning that your weekly dose of pills may literally have your name written on them. Just think — with this breakthrough in place, you might just live long enough to see the Robot Apocalypse. Fun! Video’s after the break.
[Via NY Times, thanks Serge]
http://www.engadget.com/2009/10/08/ibms-ultra-cheap-dna-transistor-dream-could-lead-to-personalize/
Nissan’s Land Glider concept car leans like a motorcycle, looks like a squashed GT-R
Motorcycles are about the most efficient (and fun) way to get around, but people in this country don’t seem to care too much — maybe worried about getting smeared all over the SUV of an eager commuter talking on his cellphone while eating breakfast and shaving. Nissan’s Land Glider could offer that fun and that efficiency in what looks to be a slightly safer package. The zero-emissions electric car seats two in-line and is just 3.6-feet wide, utilizing motorcycle tires that dip on one side when turning to enable leans of up to 17 degrees. The Tokyo Motor Show is just a few weeks away, where this interesting concept will be on display — and surely many others that are even more out there. Check out a video of this one tipping precariously just after the break.
[Via PhysOrg.com]
http://www.engadget.com/2009/10/08/nissans-land-glider-concept-car-leans-like-a-motorcycle-looks/
Renault plant in Valladolid to build Spain’s first mass-produced EV
Renault’s plant in Valladolid, Spain, will some day be one of the factories where Renault will manufacture electric cars. To make sure everything goes as planned, the Spanish government has awarded the French-based manufacturer a €70 million subvention to produce the EVs in country. Which model will be made in Valladolid was not disclosed, but it will be one of the three featured at the Frankfurt Motor Show. In addition to the EV, due in 2011, Renault also announced the production of a new low-CO2 engine and a new subcompact model to replace the unsuccessful Modus. The plant is expected to produce 100,000 cars per year in 2013, with 20 percent of them being pure electrics.
Touchscreen PCs Prompt Interface Innovations (from Wired Magazine)
Touchscreen displays are going to get a big boost from Windows 7’s built-in support for multitouch tech — but there’s a hitch: Flicking, scrolling and opening programs can be cumbersome when stubby fingers meet Windows’ tiny icons and menu items.
“PCs with touchscreens look cool, but what do you do with them?” says Jennifer Colegrove, a director at Display Search. “When it comes to the iPhone there are 50,000 applications that use touch — but what do you do on a PC with touch?”
To help answer that question, some companies are building touchscreen-centric “skins” for Windows aimed at making tactile navigation more pleasant. Two big PC companies, HP and Lenovo, as well as a startup called BumpTop, have built touch-oriented user interfaces that will run on top of Windows.
“The question is, can we re-think the touch interface as a first class citizen and provide a fresh approach to the desktop?” says Anand Agarawala, founder and CEO of Bumptop. “Not only is touch a more natural way to interact with your desktop but it also adds to your productivity.”
Touchscreens are not as popular on PCs as they are on smartphones. Only about 3 percent of the desktop and notebook PCs available today have a touchscreen, says research firm Display Search. But it is a growing market. Driven by their experiences with touchscreen based smartphones such as the iPhone and Palm Pre, consumers are craving to reach out and touch their PCs — or so PC makers think.
On Thursday, Sony announced a new touch-enabled, multimedia PC called the VAIO L Touch HD PC. The device has a 24-inch touchscreen display. Last month, Lenovo introduced the a tablet PC and a ThinkPad laptop with a touchscreen display. HP is expected to offer updated versions of its TouchSmart computers in time for the holiday season. Even Dell now offers a touchscreen option for its all-in-one desktop or nettop.
But the touch-sensitive hardware is only half the battle, since touchscreens can be difficult to use with an operating system designed for mice and keyboards.
HP was among the first to take on this challenge. In 2007, the company introduced the TouchSmart PC, a desktop with a touchscreen. Since then it has added its own user interface on top of Windows and created applications such as Recipe Box, a slickly designed program that presents each recipe in the form of a recipe card. The program also allows users to search for recipes online and save them in a similar format.
And, despite its identity as a hardware company, HP has built all the software for its touch interface. The company hopes more independent developers will jump in to create similar applications for the touchscreen.
Wanting to give its tablet PC users a better experience is also why Lenovo designed a touch interface called SimpleTap. SimpleTap is a grid of colorful square tiles. It lets users choose functions, such as previewing the camera, enabling mute, adjusting the volume or screen brightness or accessing a file, and assign them to squares within the grid.
The idea with SimpleTap is to let users get in, do a task and get out quickly, says Lenovo. “Touch is something we have looked at very hard for a long time,” says Lee Highsmith, a brand manager for Lenovo. “Windows 7 gives native support for touch so there is less likely to be contention among apps and since it is built into the OS it is easier for everybody.”
Toronto-based start up BumpTop takes a similar, but more playful approach with its software that turns a touchscreen PC into a 3-D playground of sorts.
Apart from the standard flick, pinch and scroll, BumpTop has interesting new gestures such as “shove,” which uses the little finger to move files to the left, and “fan out,” a two-fingered gesture that spreads out files.
To add realism to its 3-D look, BumpTop is built on top of the Unreal Tournament video game engine, which let the BumpTop developers give objects realistic physical properties. For instance, desktop objects like files or photos have a “mass” proportional to their size, so when a small object bumps up against a larger object, the large one doesn’t move as much.
“The physics is important thing,” says Agarawala. “It is intangible but there is something about the experience that makes it more joyful to use.”
BumpTop, which launched a beta version of its product in April, has seen more than half a million downloads of its software already.
For its part, Microsoft is supporting these custom user interface efforts. The upcoming Windows 7 operating system offers multi-touch support for the first time. Windows Vista supported single-finger touch, which only enables an extremely rough-and-ready interpretation of complex gestures, says Agarawala.
“Windows 7 gives us information such as acceleration and velocity so you can do much more complex touchscreen gestures,” he says. “So you can use five fingers if you want, something that Vista couldn’t support.”
New touchscreen interfaces open up the technology to more users but they could also end up confusing users. There are no standard sets of gestures. Some gestures may be protected by patents — Apple has filed for patents on multitouch gestures, and BumpTop is doing the same — which could limit their adoption by other interface designers. That in turn could lead to confusion among consumers: Do I scroll with one finger, or two, or three? How do I rotate the screen?
People also have to know exactly what kind of touchscreen their systems have. For instance, BumpTop uses five-finger gestures that require higher-end touchscreens. So if your PC has a more primitive touchscreen and you install BumpTop, you may find that some gestures don’t work. There’s no error message: The gestures simply don’t work.
“It’s kind of the Wild West right now with touch,” says Agarawala. “But it is also an exciting opportunity to carve a new path.”
Check out videos of how the Bumptop and Lenovo’s SimpleTap work, below.
http://www.wired.com/gadgetlab/2009/10/touch-user-interfaces/
Beyond the Genome
When scientists finished sequencing the human genome, the answers to diseases were supposed to follow. Six years later, that promise has gone unfulfilled. Genetics just isn’t that useful for predicting who gets sick, and why. The blueprint of life turned out to be an intriguing parts list.
“It’s much more complex than we had thought. There aren’t going to be easy answers,” said Teri Manolio, director of the National Human Genome Research Institute’s Office of Population Genomics. “The genome is constantly surprising us. There’s so much that we don’t know about it.”
Manolio is the lead author of a Nature article entitled “Finding the missing heritability of complex diseases.” Published Wednesday, it’s part of a major change in how scientists see the genome.
In April, several articles in the New England Journal of Medicine featured researchers arguing over why genome-wide association studies — in which thousands of genomes are compared in a hunt for disease-linked patterns — had found so little. Several months later, a massive hunt for schizophrenia genes was described as the field’s “Pearl Harbor.” At a conference this summer at the Jackson Laboratories, the shortcomings of gene-centered explanations were a starting point for talks by some of the world’s most prominent geneticists.
It’s not that genes are suddenly unimportant. Researchers are just acknowledging their variations as pieces of an extraordinarily complicated puzzle, along with how genes are turned on, how many copies are made of each, the shape of the genome itself, and how all of the genome’s protein products mix and interact.
Wired.com talked to Manolio about the future of genomics research.
Wired.com: What do you mean by “missing heritability”?
Teri Manolio: We know that diseases cluster in families. In some diseases, the risk might be two or three times higher than normal, or 30 times higher, for a relative of someone with a disease. But when we do these genomic studies, we find maybe a 50 percent increase in risk. That gap is what’s missing.
Wired.com: The numbers can get tricky. If you’ve found that someone with a certain genetic variant has double the risk of developing a disease, but the heritable risk is a hundred-fold, then we’ve only connected two percent of the heritability to genetics?
Manolio: That’s a fair way of putting it. The gap varies. In some diseases, we’re describing half of the genetic heritability. But that’s unusual. Only macular degeneration has numbers that high. In many diseases, it’s around five percent.
Wired.com: How much of the gap is caused by our inability to link genetics to conditions, and how much has non-genetic causes?
Manolio: There’s a lot of thought that this might be DNA and environment together. If you’re not exposed to adverse environmental factors, then you may never develop a given disease. With a bad enough environmental exposure, you may get a disease regardless of your genetic makeup.
Wired.com: What about aspects of our DNA that we’re just starting to study, like variations in the number of copies we have of each gene, or how genes are activated or physically arranged inside a cell?
Manolio: All of those have been suggested. At least so far, it doesn’t look like copy numbers explain a huge amount of this. But there are other places to look, and I suspect that the answer is going to be, “all of the above.”
Wired.com: How does all this fit with what the public expected of genomics? It seems we had different expectations than the scientific community.
Manolio: Well, to be honest, I think we were a bit naive about things, too. We’d hoped that when we identified where all the genes are, and all the coding regions and all the variations one could have, then that would explain everything. Those were the hopes, and then reality came crashing in.
Wired.com: What about personalized genomics testing? That’s been the big consumer application of genomics so far.
Manolio: Since we’re not explaining a huge mount of the inherited tendencies between people, then the information you get from a genotyping company may not be very apparently useful for predicting your risk of disease in the future. That’s what emerges from many of these studies: There are likely many other factors that increase your risks, and these factors are known and explain more than genomics does now. Genomics is a promising research tool, but right now it’s really a research tool.
Wired.com: How do we find the missing heritability?
Manolio: We’ll follow multiple avenues of research. We have to be humble about how this works.
Wired.com: Do we have the tools?
Manolio: Our sequencing is in good shape — the costs are coming down, we can get everyone’s base pairs read — but interpreting them is a real challenge. Technologies for epigenetics research are still developing. And there will be other needs coming down the pipeline.
Wired.com: Want to put a timetable on the research?
Manolio: I don’t think we can. In the next few years, we’ll see lots of variants associated with diseases. Many will be further investigated, and their functions determined. That’s one of the missing links here: what’s the function of all these things? We have over 400 variants identified in a whole variety of traits, but only in a few do we understand how they change a gene’s function, and how that may change biology. But these are great clues to biology.
Wired.com: Is that a better way of thinking about genetics — not in terms of answers, but clues?
Manolio: Absolutely. And if you’re a glass half-full person, then four years ago, we had practically no associations that we could replicate in multiple populations. Now there are hundreds. All of these are clues, and that’s wonderful. We just need to be patient in figuring out what they mean.
Image: From “Circos: an Information Aesthetic for Comparative Genomics.”
See Also:
- To Understand the Blueprint of Life, Crumple It
- New Gene Switch Sows Epigenetic Doubts
- Whew! Your DNA Isn’t Your Destiny
- Exploring the Genetic Differences Between Chimps and Humans
- Superfast Genome Sequencing Goes Global
Citation: “Finding the missing heritability of complex diseases.” By Teri A. Manolio, Francis S. Collins, Nancy J. Cox, David B. Goldstein, Lucia A. Hindorff, David J. Hunter, Mark I. McCarthy, Erin M. Ramos, Lon R. Cardon, Aravinda Chakravarti, Judy H. Cho, Alan E. Guttmacher, Augustine Kong, Leonid Kruglyak, Elaine Mardis, Charles N. Rotimi, Montgomery Slatkin, David Valle, Alice S. Whittemore, Michael Boehnke, Andrew G. Clark, Evan E. Eichler, Greg Gibson, Jonathan L. Haines, Trudy F. C. Mackay, Steven A. McCarroll & Peter M. Visscher. Nature, Vol. 461, No. 7265. October 8, 2009.
Brandon Keim’s Twitter stream and reportorial outtakes; Wired Science on Twitter. Brandon is currently working on a book about ecosystem and planetary tipping points.
http://www.wired.com/wiredscience/2009/10/beyond-the-genome/
NASA Refines Asteroid Apophis’ Path Toward Earth
Asteroid Apophis was discovered on June 19, 2004. (Credit: UH/IA)
Using updated information, NASA scientists have recalculated the path of a large asteroid. The refined path indicates a significantly reduced likelihood of a hazardous encounter with Earth in 2036.
The Apophis asteroid is approximately the size of two-and-a-half football fields. The new data were documented by near-Earth object scientists Steve Chesley and Paul Chodas at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. They will present their updated findings at a meeting of the American Astronomical Society’s Division for Planetary Sciences in Puerto Rico on Oct. 8.
“Apophis has been one of those celestial bodies that has captured the public’s interest since it was discovered in 2004,” said Chesley. “Updated computational techniques and newly available data indicate the probability of an Earth encounter on April 13, 2036, for Apophis has dropped from one-in-45,000 to about four-in-a million.”
A majority of the data that enabled the updated orbit of Apophis came from observations Dave Tholen and collaborators at the University of Hawaii’s Institute for Astronomy in Manoa made. Tholen pored over hundreds of previously unreleased images of the night sky made with the University of Hawaii’s 2.2-meter (88-inch) telescope, located near the summit of Mauna Kea.
Tholen made improved measurements of the asteroid’s position in the images, enabling him to provide Chesley and Chodas with new data sets more precise than previous measures for Apophis. Measurements from the Steward Observatory’s 2.3 meter (90-inch) Bok telescope on Kitt Peak in Arizona and the Arecibo Observatory on the island of Puerto Rico also were used in Chesley’s calculations.
The information provided a more accurate glimpse of Apophis’ orbit well into the latter part of this century. Among the findings is another close encounter by the asteroid with Earth in 2068 with chance of impact currently at approximately three-in-a-million. As with earlier orbital estimates where Earth impacts in 2029 and 2036 could not initially be ruled out due to the need for additional data, it is expected that the 2068 encounter will diminish in probability as more information about Apophis is acquired.
Initially, Apophis was thought to have a 2.7 percent chance of impacting Earth in 2029. Additional observations of the asteriod ruled out any possibility of an impact in 2029. However, the asteroid is expected to make a record-setting — but harmless — close approach to Earth on Friday, April 13, 2029, when it comes no closer than 29,450 kilometers (18,300 miles) above Earth’s surface.
“The refined orbital determination further reinforces that Apophis is an asteroid we can look to as an opportunity for exciting science and not something that should be feared,” said Don Yeomans, manager of the Near-Earth Object Program Office at JPL. “The public can follow along as we continue to study Apophis and other near-Earth objects by visiting us on our AsteroidWatch Web site and by following us on the @AsteroidWatch Twitter feed.”
The science of predicting asteroid orbits is based on a physical model of the solar system which includes the gravitational influence of the sun, moon, other planets and the three largest asteroids.
NASA detects and tracks asteroids and comets passing close to Earth using both ground and space-based telescopes. The Near-Earth Object Observations Program, commonly called “Spaceguard,” discovers these objects, characterizes a subset of them and plots their orbits to determine if any could be potentially hazardous to our planet.
JPL manages the Near-Earth Object Program Office for NASA’s Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena. Cornell University, Ithaca, N.Y., operates the Arecibo Observatory under a cooperative agreement with the National Science Foundation in Arlington, Va.
For more information about asteroids and near-Earth objects, visit: http://www.jpl.nasa.gov/asteroidwatch
http://www.sciencedaily.com/releases/2009/10/091007171926.htm
Large-Scale Cousin Of Elusive ‘Magnetic Monopoles’ Found At NIST
Magnetic monopoles are created (top) when the spin of an ion in one corner of a spin ice crystal is knocked askew, creating a monopole (red sphere) and adjacent antimonopole (blue sphere). Neutron scattering at the NCNR allowed the team to see the spin ice’s transition from its normal state (center) to the monopole state. Monopoles scatter neutrons in a telltale fashion indicated by the red arrows in (bottom.) (Credit: Image courtesy of NIST)
Any child can tell you that a magnet has a “north” and a “south” pole, and that if you break it into two pieces, you invariably get two smaller magnets with two poles of their own. But scientists have spent the better part of the last eight decades trying to find, in essence, a magnet with only one pole. A team working at the National Institute of Standards and Technology (NIST) has found one.
In 1931, Paul Dirac, one of the rock stars of the physics world, made the somewhat startling prediction that “magnetic monopoles,” or particles possessing only a single pole—either north or south—should exist. His conclusion stemmed from examining a famous set of equations that explains the relationship between electricity and magnetism. Maxwell’s equations apply to long-known electric monopole particles, such as negatively charged electrons and positively charged protons; but despite Dirac’s prediction, no one has found magnetic monopole particles.
Now, a research team working at NIST’s Center for Neutron Research (NCNR), led by Hiroaki Kadowaki of Tokyo Metropolitan University, has found the next best thing. By creating a compound that under certain conditions forms large, molecule-sized monopoles that behave exactly as the predicted particles should, the team has found a way to explore magnetic monopoles in the laboratory, not just on the chalkboard. (Another research team, working simultaneously, published similar findings in Science last month.)
“These are not the monopole particles Dirac predicted—ours are huge in comparison—but they behave like them in every way,” says Jeff Lynn, a NIST physicist. “Their properties will allow us to test how theoretical monopole particles should behave and interact.”
The team created their monopoles in a compound made of oxygen, titanium and dysprosium that, when cooled to nearly absolute zero, forms what scientists call “spin ice.” The material freezes into four-sided crystals (a pyramid with a triangular base) and the magnetic orientation, or “spin,” of the ions at each of the four tips align so that their spins are balanced—two spins point inward and two outward. But using neutron beams at the NCNR, the team found they could knock one of the spins askew so that instead three point in, one out … “creating a monopole, or at least its mathematical equivalent,” Lynn said.
Because every crystal pyramid shares its four tips with adjacent pyramids, flipping the spin of one tip creates an “anti-monopole” in the next pyramid over. The team has created monopole-antimonopole pairs repeatedly in a relatively large chunk of the spin ice, allowing them to confirm the monopoles’ existence through advanced imaging techniques such as neutron scattering.
While the findings will not tell the team where in the universe to search for Dirac’s still-elusive magnetic monopole particles, Lynn says that examining the spin ice will permit scientists to test certain predictions about monopoles. “Maxwell’s equations indicate that monopoles should obey Coulomb’s Law, which indicates their interaction should weaken as distance between them increases,” he says. “Using the spin ice crystals, we can test ideas like this.”
http://www.sciencedaily.com/releases/2009/10/091007230321.htm
To Peer Inside A Living Cell: Quantum Mechanics Could Help Build Ultra-high-resolution Electron Microscopes
An electron microscope image of a butterfly’s wings. (Credit: Graphic: Christine Daniloff; electron micrograph image courtesy of the NSF)
Electron microscopes are the most powerful type of microscope, capable of distinguishing even individual atoms. However, these microscopes cannot be used to image living cells because the electrons destroy the samples.
Now, MIT assistant professor Mehmet Fatih Yanik and his student, William Putnam, propose a new scheme that can overcome this limitation by using a quantum mechanical measurement technique that allows electrons to sense objects remotely. Damage would be avoided because the electrons would never actually hit the imaged objects.
Such a non-invasive electron microscope could shed light on fundamental questions about life and matter, allowing researchers to observe molecules inside a living cell without disturbing them. Yanik and Putnam report their new approach in the October issue of Physical Review A — Rapid Communications.
If successful, such microscopes would surmount what Nobel laureate Dennis Gabor concluded in 1956 was the fundamental limitation of electron microscopy: “the destruction of the object by the exploring agent.”
Electron flow
Electron microscopes use a particle beam of electrons, instead of light, to image specimens. Resolution of electron microscope images ranges from 0.2 to 10 nanometers — 10 to 1,000 times greater than a traditional light microscope. Electron microscopes can also magnify samples up to two million times, while light microscopes are limited to 2,000 times.
However, biologists have been unable to unleash the high power of electron microscopes on living specimens, because of the destructive power of the electrons.
The radiation dose received by a specimen during electron microscope imaging is comparable to the irradiation from a 10-megaton hydrogen bomb exploded about 30 meters away. When exposed to such energetic electron beams, biological specimens experience rapid breakdown, modification of chemical bonds, or other structural damages.
Although there exist special chambers to keep biological samples in a watery environment within the high vacuum required for electron microscopes, chemical preservation or freezing, which kill cells, is still required before biological samples can be viewed with existing electron microscopes.
In the proposed quantum mechanical setup, electrons would not directly strike the object being imaged. Instead, an electron would flow around one of two rings, arranged one above the other. The rings would be close enough together that the electron could hop easily between them. However, if an object (such as a cell) were placed between the rings, it would prevent the electron from hopping, and the electron would be trapped in one ring.
This setup would scan one “pixel” of the specimen at a time, putting them all together to create the full image. Whenever the electron is trapped, the system would know that there is a dark pixel in that spot.
Though technical challenges would need to be overcome (such as preventing the imaging electron from interacting with electrons of the metals in the microscope), Yanik believes that eventually such a microscope could achieve a few nanometers of resolution. That level of resolution would allow scientists to view molecules such as enzymes in action inside living cells, and even single nucleic acids — the building blocks of DNA.
Yanik, the Robert J. Shillman Career Development Assistant Professor of Electrical Engineering, says he expects the work will launch experimental efforts that could lead to a prototype within the next five years.
Charles Lieber, professor of chemistry at Harvard and an expert in nanoscale technology, describes Yanik’s proposal as a “highly original and exciting concept for ‘noninvasive’ high-resolution imaging” using an electron microscope.
“From my perspective, it has the potential to be a breakthrough for those working with sensitive samples, such as biological imaging,” Lieber says. “Also, in general terms I find his work intellectually exciting because it is not incremental but takes a quantum (excuse the pun) jump forward through creative thinking.”
http://www.sciencedaily.com/releases/2009/10/091006134825.htm
New Aluminum-water Rocket Propellant Promising For Future Space Missions
Purdue is working with NASA, the Air Force Office of Scientific Research and Pennsylvania State University to develop a new type of rocket propellant made of a frozen mixture of water and “nanoscale aluminum” powder. The propellant, called ALICE, is more environmentally friendly and could be manufactured on the moon, Mars and other water-bearing bodies. Holding a rocket launched earlier this year using the propellant, from left, are: mechanical engineering undergraduate student Cody Dezelan, mechanical engineering graduate student Tyler Wood, mechanical engineering professor Steven Son, aeronautics and astronautics graduate student Mark Pfeil, mechanical engineering doctoral student Travis Sippel, aeronautics and astronautics research assistant professor Timothée Pourpoint, and postdoctoral researcher John Tsohas. (Credit: Purdue University photo/Andrew Hancock)
Researchers are developing a new type of rocket propellant made of a frozen mixture of water and “nanoscale aluminum” powder that is more environmentally friendly than conventional propellants and could be manufactured on the moon, Mars and other water-bearing bodies.
The aluminum-ice, or ALICE, propellant might be used to launch rockets into orbit and for long-distance space missions and also to generate hydrogen for fuel cells, said Steven Son, an associate professor of mechanical engineering at Purdue University.
Purdue is working with NASA, the Air Force Office of Scientific Research and Pennsylvania State University to develop ALICE, which was used earlier this year to launch a 9-foot-tall rocket. The vehicle reached an altitude of 1,300 feet over Purdue’s Scholer farms, about 10 miles from campus.
“It’s a proof of concept,” Son said. “It could be improved and turned into a practical propellant. Theoretically, it also could be manufactured in distant places like the moon or Mars instead of being transported at high cost.”
Findings from spacecraft indicate the presence of water on Mars and the moon, and water also may exist on asteroids, other moons and bodies in space, said Son, who also has a courtesy appointment as an associate professor of aeronautics and astronautics.
The tiny size of the aluminum particles, which have a diameter of about 80 nanometers, or billionths of a meter, is key to the propellant’s performance. The nanoparticles combust more rapidly than larger particles and enable better control over the reaction and the rocket’s thrust, said Timothée Pourpoint, a research assistant professor in the School of Aeronautics and Astronautics.
“It is considered a green propellant, producing essentially hydrogen gas and aluminum oxide,” Pourpoint said. “In contrast, each space shuttle flight consumes about 773 tons of the oxidizer ammonium perchlorate in the solid booster rockets. About 230 tons of hydrochloric acid immediately appears in the exhaust from such flights.”
ALICE provides thrust through a chemical reaction between water and aluminum. As the aluminum ignites, water molecules provide oxygen and hydrogen to fuel the combustion until all of the powder is burned.
“ALICE might one day replace some liquid or solid propellants, and, when perfected, might have a higher performance than conventional propellants,” Pourpoint said. “It’s also extremely safe while frozen because it is difficult to accidentally ignite.”
The research is helping to train a new generation of engineers to work in academia, industry, for NASA and the military, Son said. More than a dozen undergraduate and graduate students have worked on the project.
“It’s unusual for students to get this kind of advanced and thorough training – to go from a basic-science concept all the way to a flying vehicle that is ground tested and launched,” he said. “This is the whole spectrum.”
Research findings were detailed in technical papers presented this summer during a conference of the American Institute of Aeronautics and Astronautics. The papers will be published next year in the conference proceedings.
Leading work at Penn State are mechanical engineering professor Richard Yetter and assistant professor Grant Risha.
The Purdue portion of the research is based at the university’s Maurice J. Zucrow Laboratories, where researchers created a special test cell and control room to test the rocket. The rocket’s launching site was located on a facility maintained by Purdue’s School of Veterinary Medicine.
“Having a launching site near campus greatly facilitated this project,” Pourpoint said.
Other researchers previously have used aluminum particles in propellants, but those propellants usually also contained larger, micron-size particles, whereas the new fuel contained pure nanoparticles.
Manufacturers over the past decade have learned how to make higher-quality nano-aluminum particles than was possible in the past. The fuel needs to be frozen for two reasons: It must be solid to remain intact while subjected to the forces of the launch and also to ensure that it does not slowly react before it is used.
Initially a paste, the fuel is packed into a cylindrical mold with a metal rod running through the center. After it’s frozen, the rod is removed, leaving a cavity running the length of the solid fuel cylinder. A small rocket engine above the fuel is ignited, sending hot gasses into the center hole, causing the ALICE fuel to ignite uniformly.
“This is essentially the same basic procedure used in the space shuttle’s two solid-fuel rocket boosters,” Son said. “An electric match ignites a small motor, which then ignites a bigger motor.”
Future work will focus on perfecting the fuel and also may explore the possibility of creating a gelled fuel using the nanoparticles. Such a gel would behave like a liquid fuel, making it possible to vary the rate at which the fuel is pumped into the combustion chamber to throttle the motor up and down and increase the vehicle’s distance.
A gelled fuel also could be mixed with materials containing larger amounts of hydrogen and then used to run hydrogen fuel cells in addition to rocket motors, Son said.
Adapted from materials provided by Purdue University. Original article written by Emil Venere.
http://www.sciencedaily.com/releases/2009/10/091007161127.htm
