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| SCIENCE & TECHNOLOGY |
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Wearable electronic clothes UNDERSTANDING
THE UNIVERSE |
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Wearable electronic clothes ADVANCES in textile technology, computer engineering and materials science are promoting a new breed of functional fabrics resulting in some truly smart and clever clothing. Realisation of this vision could be possible with the advent of wearable electronic textiles, where functionality is incorporated into the fabric. Clothing is being developed for protection from chemical, biological and nuclear threats. Besides, with the development of polymers with exotic qualities in terms of their mechanical, electrical and magnetic properties, scientists are ready to design electronic clothing with various specialties like heating, cooling, illuminating of body etc. Fashion designers are adding wires, circuits, and optical fibers to traditional textiles, creating garments that glow in the dark or keep the wearer warm. Meanwhile, electronics engineers are sewing conductive threads and sensors into body suits that can map users’ whereabouts and respond to environmental stimuli. Researchers agree that the development of genuinely interactive electronic textiles is technically possible, and that challenges in scaling up the handmade garments will eventually be overcome. Ideas include the development of jacket-sleeve keypads for controlling cell phones, pagers, or MP3 players, and sportswear with integral fabric sensors and display panels, ideas for monitoring heart rate and blood pressure during a gym workout or morning run. Clothing fitted with textile global positioning system technology could also be suitable for locating skiers or mountaineers in bad weathers or even for keeping a watch on young children.
Advances so far Adopting electronic displays (LEDs) technologies to create colourful, novelty clothing items for example, glow-in-the-dark bridal gown, sparkling cocktail dresses, and costumes for opera singer. Further progress is expected in the form of tailor-made clothing. * Fibres powered by tiny, rechargeable batteries that are turned on by the wearer via a hidden switch causing the fibres to give shininess when the lights are dimmed. * Development of a flexible, battery-powered optical fibre screen that can be woven into clothing. A prototype version integrated into a jacked displaying symbols is already in the market and more sophisticated versions may support advertising slogans, safety notices, or simply a range of different geometric patterns can be switched on and off. * Production of low-cost jackets for joggers and walkers with a pulse monitor stitched to the left cuff. embedded sensors control conductive material on the back of the jacket to keep the wearer warm should the temperature drop, while electroluminescent wires are fixed to pockets and hems to light up in the dark as a safety feature. The marriage of woven fabric with electronics is finding favour in the world of interior design as well inform of electro-textile wall panels. The panel exploits reflective coloring. The fabric contains interwoven stainless steel yarns, painted with thermochromic inks, which are connected to drive electronics programmed to change colour in response to heat from the conducting wires. At the outset, main user are going to be medical, military , and industrial areas with compelling applications and affordability. The simulation environment is already being used to model a garment that can sense its own shape thus helping patients to learn about their exercise requirement. Creating a wearable version of a giant textile “sensornet’ designed to detect noise It is envisaged that efforts should be to stay as close as possible to conventional large-scale cutting and sewing techniques when thinking about how electronic textile clothing could be made. Cutting electronic cloth clearly makes it more difficult to make good connections between different parts of the same garments and one solution to it could be the manufacturing of seamless clothing, which would avoid the cutting and stitching problem altogether. The cost of developing and manufacturing such sophisticated fabrics is likely to put them beyond the reach of the fashion industry for the time being. Connections will be main point of weakness in electronic clothing. Moreover, researchers have yet to answer the million-dollar question, perhaps critical to consumer acceptance, about the washing of electronic fabrics. The challenge for industry is also to build in the security and privacy for the user of electronic clothing from hackers. Whatever the technical obstacles,
researchers involved in the development of interactive electronic clothing appear universally confident that context-aware coast and sensory shirts are only a matter of time. |
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UNDERSTANDING
THE UNIVERSE Missiles are rockets. Therefore, in order to move they have to produce hot gases that exit from behind with great speed and propel the rocket forward. The fuels used are solids or liquids, with the requirement that the oxygen required for burning is also carried up in one form or another. Since most of the mass of the rocket at the time of its launch is in the fuel one is always looking for those fuels that can deliver largest thrust per kilogram. The ideal seems to be to use liquid hydrogen and liquid oxygen. This is not considered practical and economic for all missile applications. Missiles can use inertial guidance, the Global Positioning System of satellites or terrain guidance where one compares the sensed picture of the terrain with one stored in the guidance programme of the missile. If liquid engines are used the thrust can be cut off as required. Manoeuvring is done using auxiliary thrusters and in terminal stages, aerodynamic vanes. In some devotional rituals, people walk or run over fire. They claim that is not at all painful. Is there any scientific reason for this? If the sole of a wet foot touches hot coals only for a tiny fraction of a second there is not enough transfer of heat to seriously affect the foot. Standing on such a fire for a little longer would be very harmful. That is why during those rituals people are asked to run across the hot coals and not stand on them. Sometimes the performers also run a burning stick over their arms. This is usually done after shaving the arms, because any hair on them would be singed in the briefest contact. Please do not start performing these feats without supervision merely because I have given you this explanation. Playing with fire is never absolutely safe. From where does the earth receive the energy to rotate around its own axis and to orbit the sun? The energy and momentum of the earth and other heavenly bodies primarily came from the method of their formation. If we take the generally accepted theory of formation of the solar system then these energies are derived from the original energy and momentum of the large cloud of gas and dust that gave birth to the system through gravitational contraction. In the processes of such contraction the overall angular momentum had to be conserved and enormous amount of gravitational energy was converted into kinetic energy. Once a planet like the earth is set into rotation or circulation around the sun we do not need any engine to keep it going. There are perturbations caused by the various gravitational fields it might encounter. Moving at uniform speed does not require any energy. I am neglecting the small changes that occur through tidal interaction with other heavenly bodies. (It is well known that the speed of rotation of the earth might have been reduced over billions of years because of the tidal friction of the
moon). |
How does a missile work? What is its source of energy? How is it guided to a particular target?