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Varied uses of geo-textiles Tongue as computer control pad Trends
THIS UNIVERSE |
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Varied uses of geo-textiles In recent years, there has been an increasing use of geo-textiles for a variety of applications, including the construction of roads and bridges as well as the prevention of soil erosion and reinforcement of heavy concrete structures. As it is, geo-textiles are employed for use as horizontal blankets for soil consolidation in embankments. On the other hand, geo-textiles fabricated out of coir are used in areas where it takes vegetation a long time to get stabilised. Similarly,in sandy stretches geo-textiles prevent erosion caused by wind. Jute geo-textiles are considered useful for dust control. The geo-textiles made of natural fibres are both eco-friendly and bio-degradable. However, geo-textiles made out of synthetic polymers, including polypropylene, polyesters and polyethylene, have the distinct advantage of withstanding decay and degradation under biological and chemical processes. “When the durability of geo-textiles is important, it is advisable to use polymeric goe-textiles. Poly propylene is the most most commonly used polymer in synthetic geo-textiles. For high strength geo-textiles, polyester is the preferred polymer. When exceptional resistance is required, HDPE(High Density Polyethylene) is used”, says Anant Kanoi, Managing Director , Techfab India Ltd which is the largest manufacturers of geo-textiles in the country. For reinforcement applications, geo-textiles made from synthetic fibres are used. On its part SASMIRA(Synthetic and Art Silk Mills Research Association) has successfully demonstrated the potential use of geo-textiles for pavement overlay. Reinforcing the roads with synthetic geo-textiles helped avoid cracks and potholes. Similarly, a project undertaken by Techfab India in association with PWD(Public Works Department), Pune, and Indian Institute of Technology(IIT),Bombay has shown that use of geo-textiles prevents the deterioration of roads over a period of time. Geo-textiles are also classified as woven or non woven. While woven geo-textiles are produced by interlocking of yarns to leave a finished material that has a discernable warp and weft, non woven geo-textiles are produced either by heat bonding or chemical bonding. According to M.K.Bardhan, Director, SASMIRA, “the awareness about the application of geo-textiles in India is not much at the moment in spite of its tremendous potential for production, consumption and export”. The Ministry of Textiles is sponsoring research and development projects to develop diversified geo-textile products from jute and coir.Jute Manufacturers Development Council in Kolkatta and Coir Board in Bangalore are coordinating such projects through R&D institutes and are creating awareness about use of geo-textiles in various applications. Jute and coir geo-textiles have been used in construction of roads, in soil erosion systems, vertical drains in embankments in different parts of the country.
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Tongue as computer control pad The tireless tongue already controls taste and speech, helps kiss and swallow and fights germs. Now scientists hope to add one more ability to the mouthy muscle, and turn it into a computer control pad. Georgia Tech researchers believe a magnetic, tongue-powered system could transform a disabled person’s mouth into a virtual computer, teeth into a keyboard — and tongue into the key that manipulates it all. “You could have full control over your environment by just being able to move your tongue,” said Maysam Ghovanloo, a Georgia Tech assistant professor who leads the team’s research. The group’s Tongue Drive System turns the tongue into a joystick of sorts, allowing the disabled to manipulate wheelchairs, manage home appliances and control computers. The work still has a ways to go — one potential user called the design “grotesque” — but early tests are encouraging. The system is far from the first that seeks a new way to control electronics through facial movements. But disabled advocates have particularly high hopes that the tongue could prove the most effective. “This could give you an almost infinite number of switches and options for communication,” said Mike Jones, a vice president of research and technology at the Shepherd Center, an Atlanta rehabilitation hospital. “It’s easy, and somebody could learn an entirely different language.” That’s quite a contrast to the handful of methods already available to the hundreds of thousands of Americans who are disabled from the neck down. The “sip and puff” technique, which lets people issue commands by inhaling and exhaling into a tube, is among the most popular. But it offers users only four different commands, limiting their options. Control systems that use sophisticated pads to measure neck and head movements are also widespread, but using the hardware can be tiring, and frustrating on smaller electronics like computers. And while newer innovations that track eye movement are promising, they can be costly, slow and susceptible to mixed signals. The tongue, though, is a more flexible, sensitive and tireless option. And like other facial muscles, its functions tend to be spared in accidents that can paralyze most of the rest of the body, because the tongue is attached to the brain, not the spinal cord. The tongue’s promise has long enticed scientists. In the 1960s, research work focused on turning the tongue into a primitive lens by attaching electrodes to the tissue. More recent studies have connected a camera that activates tongue electrodes in the shape of an object, helping blind people sense images. — AP
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Trends They used NASA’s Chandra X-ray Observatory and Hubble Space Telescope to study the cluster, known a MACSJ0025.4-1222. They can see a clear separation between dark and ordinary matter, answering a crucial question about whether dark matter interacts with itself other than via gravitational forces, the researchers said on Wednesday. “Dark matter makes up five times more matter in the universe than ordinary matter,” said Marusa Bradac of the University of California Santa Barbara, who led the work.
— Reuters
Even viruses can get sick Even viruses can go down with a viral infection, French scientists reported on Wednesday, in a discovery that may help explain how they swap genes and evolve so rapidly. A new strain of giant virus was isolated from a cooling tower in Paris and found to be infected by a smaller type of virus, named Sputnik, after the first man-made satellite. Sputnik is the first example of a virus infecting another virus to make it sick. Bernard La Scola and colleagues from the Universite de la Mediterranee in Marseille reported in the journal Nature that Sputnik was able to achieve a remarkable degree of gene mixing by “looting” genes from its host virus and other organisms. — Reuters
Cows seem to know Most cattle that were grazing or resting tended to align their bodies in a north-south direction, a team of German and Czech researchers reports in Tuesday’s issue of Proceedings of the National Academy of Sciences. And the finding held true regardless of what continent the cattle were on, according to the study led by Hynek Burda and Sabine Begall of the faculty of biology at the University of Duisburg-Essen in Germany. — AP
Radiation can zap cancer Precisely targeted radiation therapy can eradicate tumors that have spread to other parts of the body, offering more months or years of life to patients who have no other options, U.S. researchers reported on Wednesday. They said new radiation techniques can attack metastases — tumors that have spread — one by one. —
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THIS UNIVERSE
We have a stone and a plastic ball of same mass. We drop both of them simultaneously. But the ball bounces up and the stone does not. Why? Let us examine what happens to the energy and momentum of the two balls when they hit the ground. First the stone ball: It is possible that the stone ball will break the ground, scatter some dust around, perhaps itself be chipped or broken. Therefore its energy will be used up in all these things. Depending on the height from which it falls, quite some energy would be used up in heating the ground and the fragments produced. The nature of these happenings might vary depending on the structure of the ball and the ground surface and the height from which the ball is dropped. Most of the energy and momentum would be dissipated. Now consider the other ball: If it is like a tennis ball or something like a football the destruction of the ball and the ground would be much less. Little energy would be lost. If the ground is hard the ball would be compressed at the time of impact and its decompression would make it bounce up. Yes, even the earth would move a bit but because of its infinitely greater mass this would be minuscule, even though after the collision the momentum of the earth and the ball would be equal and opposite. There might be a little loss in heat and sound, but not much. What I have said for the two balls mentioned above would also apply to a stiff plastic ball. Why does a pilot not fall down when his aeroplane does a vertical loop? If you take a very small bucket, fill it half with water, tie a rope to its handle and rotate it in vertical plane you will find that the water does not fall out. This is because of the centrifugal force. Water is pushed to the bottom of the bucket irrespective of whether it is up or down. That is the reason that the pilot does not fall down when he does a vertical loop. Why does the earth spin? The earth was probably born through condensation of a large cloud of gas and dust that was spinning slowly. You might justifiably ask: “Why was cloud spinning?” The answer to that is that the probability of zero spin is zero. A small spin in any direction is amplified during condensation in order to conserve angular momentum. If you have seen a movie of an ice skater you would recall that when a slowly rotating skater pulls in her arms she begins to rotate very fast. |
Depending upon the end use, geo-textiles can be manufactured out of either synthetic or natural fibers. Abundantly available jute and coir are ideal natural material used in geo-textiles meant for certain cost effective applications like erosion control and regeneration of soil. 
Astronomers have captured images of a powerful collision of galaxy clusters and say it may shed light on the behaviour of dark matter.
Talk about animal magnetism, cows seem to have a built-in compass. No bull: Somehow, cattle seem to know how to find north and south, say researchers who studied satellite photos of thousands of cows around the world.