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Monorail for mass transport Plastic magnet breakthrough Meteorites and evolution Prof Yash
Pal
UNDERSTANDING THE UNIVERSE |
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Monorail
for mass transport Monorails
are providing answers to these problems and thus are becoming popular
mass transit systems of future all over the world. In India also
recently the government of West Bengal has announced about the
development of a monorail project in Kolkata. The monorail
technology is developing very fast and maglev monorails are expected
to be operational in the near future. While monorail is not perfect
for every situation, the following arguments present a strong case for
the narrow beamed wonders. * Monorails are safe whether they are of
the straddle-beam or suspended variety because the nature of their
design which does not allow derailments. * Monorails are
cost-effective. Not only capital but operational costs of heavy rail
as compared to monorail are also very high. * Monorails are
environment friendly. Since they are electric powered, monorails are
non-polluting. Most run on rubber tyres and are very quiet. *
Steel
wheels on steel rail grind and wear; therefore, both wheels and rail
require far more care than monorail. This alone makes profit
impossible with heavy rail. Frequent vehicle breakdowns during
operation also make heavy rail much less reliable than monorail. *
Monorail doesn’t require a lot of the area to be torn up during
construction and the elevated guideway does not create problem of
displacement for people on the ground. Moreover, monorail beamway can
be installed far faster than the alternatives. * Monorail are
popular with people / taxpayers. In various countries, voters have
demonstrated their preference for monorail more than once.
Bottlenecks
A multitude of reasons can explain why the development of
monorails is not as it has to be in comparison to other transit
systems. Some of them are: * Despite the fact that there are dozens
of successful transit monorails around the world, some put forward
reasons like "There aren’t any transit monorails. We shouldn’t
build something that hasn’t been proven". It’s a ludicrous
reason, but it sticks for some reason. * The conventional rail
industry has established a stronghold and monorail is often
discouraged by consultants. * Manufacturers of monorails usually
build all kinds of rail systems besides their monorail product. If our
city wants a more expensive technology than monorail or their
consultant steers them in another direction, manufacturers are
ever-so-happy to oblige by selling them something more expensive. *
Quite often, people make the assumption that any elevated rail or
peoplemover is a monorail. When they are improperly lumped together
with monorail, the disadvantages are assumed to be common with real
monorails. Hence, monorails get portrayed in a negative light. |
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Plastic magnet breakthrough British scientists have developed the world’s first practical plastic magnet. The breakthrough could lead to new advances in computing and medical applications. In the past, magnets were always metal. Then in 2001 a team of U.S. chemists from the University of Nebraska-Lincoln showed that it was possible to make a magnet out of plastic. But their magnet, and similar ones which followed, suffered a major drawback. They only worked at ultra-low temperatures, making them totally unsuitable for use in everyday products. The new plastic magnet developed by the University of Durham`s organic electroactive materials group is the first in the world to operate at room temperature. In an elementary test, the scientists have used it to pick up iron filings from a laboratory bench. The magnet is a polymer - a chain of molecules - made from two compounds, called PANi and TCNQ, that have unusual electrical properties. Normally, magnetism is generated as a result of electron spins lining up. In the plastic, a similar effect is achieved by lining up charged particles called free radicals. At first the plastic showed little sign of becoming magnetic. After three months of failure the researchers were about to give up when they decided to test the polymer samples one last time. To their surprise, they found that the plastic had developed magnetic properties, New Scientist magazine reported. Although the effect is weak compared with conventional metal magnets, the researchers are confident it can be improved. Naveed Zaidi, who heads the team, said: ‘’The reaction is not yet 100 per cent efficient along the polymer and the strength of effect varies throughout the material. Once we increase this efficiency this overall strength will certainly increase.’’ The magnetic plastic is mostly likely to be used for coating computer hard discs, which could lead to a new generation of high- capacity discs. — DPA
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Meteorites and evolution US scientists have discovered that meteorites, particularly iron meteorites, may have been critical to the evolution of life on earth.
In a study funded by the National Aeronautics and Space Administration (NASA), University of Arizona scientists have found that meteorites could have easily provided more phosphorus than naturally occurs on earth, enough to give rise to biomolecules that eventually assembled into living, replicating organisms. “Because phosphorus is much rarer in the environment than in life, understanding the behaviour of phosphorus on the early earth gives clues to life’s origin, ” said Matthew Pasek, a doctoral candidate in UA’s planetary sciences department and Lunar and Planetary Laboratory. “Meteorites have several different minerals that contain phosphorus,” Pasek said in a statement. “The most important one, which we’ve worked with most recently, is iron-nickel phosphide, known as
schreibersite.”— PTI
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UNDERSTANDING THE UNIVERSE If we expose any object to heat, it expands. Earth is also exposed continuously to sun’s heat. Is it expanding? If so, how much? The earth heats up during the day and cools during the night. Because of our oceans and the atmosphere, the day and night temperatures do not go through such extremes as they would if ours were a dead planet, say like Mars or Mercury. Yet there is no question that rocks on the surface, as also our buildings and bridges go through a cycle of expansion and contraction every day. This does produce some weathering and crumbling. But the temperature of the whole earth does not change that much. If you were to go a few metres below ground you would find that compared to the surface, you are not as hot during a summer day, or as cold during a winter night. Our earth as a whole does not inflate or deflate significantly because of the varying amounts of isolation. I must, however, qualify this statement. Consider the oceans. Temperature of the sea changes with seasons but since the winter and summer hemispheres are connected the average temperature is nearly constant. Should there be a climate change, say due to global warming and the average temperature of the sea increases by 5 degrees Celsius something dramatic might happen. Volume of the sea would increase due to thermal expansion of water. If we assume that the spread of the oceans will remain about the same and also that the average depth of the ocean is 3 km, increase in the height of the water would be about 3 metres! That could be very bad for coastal areas and small islands. Had there been plenty of oxygen in the sun to burn all the hydrogen of the sun then what would have been the life of the sun? What would have happened to the steam and water in the sun? I am intrigued by this question because the questioner has preceded this by telling me how the main reaction producing the energy of the sun is fusion of hydrogen into helium. It should be recognised that when fusion is operating at temperatures of 15 million degrees, with each fusion producing millions of times greater energy than that available through a chemical reaction, there is no point in talking about interaction of atomic hydrogen and atomic oxygen to produce water and steam. The atoms as we know them have no existence at temperatures we are dealing within the energy producing central part of the sun. It has been said that one effect of using a mobile for a long time is that it might cause cancer. It is said that keeping the mobile phone away from your brain by using a hands-free set would reduce this risk. What is the truth in all this? Mobile, or cellular, telephones use a rather intense signal of microwave radiation. People have worried that this might affect the brain. I do not think there is any agreement on that in spite of several studies that have been made. It is argued that the effect might be only some minor heating, pretty much like what happens in microwave ovens. However, one could not rule out that there are some other effects. It pays to be careful, but one should not become paranoiac. Why do we find tides at the seashore but not inside the sea? It is calm inside. If you were sitting on a satellite, far out in space, and had an instrument to measure the distance to the sea level below, you would find a bulge in the sea following the moon. You would also see a bulge on the opposite side of the moon. The level of the sea at right angle to the earth-moon line would be lower. This is what the whole tidal phenomenon is — primarily so, neglecting the effect of the sun for the time being. The tidal force does not care how far you are from the coast. The fact that you are more aware of the rise and fall of water when you are near the coast is because you something to compare with, namely the level of the coast. In the middle of the sea all the water in the neighbourhood goes up and down and one I unaware of this gradual up and down motion twice day.
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New materials from nanodotsNanotechnologists
envision using tiny structures to create ultrastrong materials and to
build memory chips that store entire libraries. But these visions
require making matter behave in exceptionally orderly ways. Now,
materials scientists Jagdish Narayan and Ashutosh Tiwari of North
Carolina State University (NCSU) in Raleigh have induced tiny
particles, or nanodots, of nickel to spontaneously assemble into
exceptionally uniform, three-dimensional arrays of macroscopic size.
With this method, they’ve also created blends of copper nanodots
and tin that they say are harder than steel. The company Kopin in
Taunton, Mass., is already applying the technique to semiconductors
that they use to manufacture unusually efficient light-emitting
diodes. "Living glue" for joints By combining
stem cell science with orthopedic surgery, a team of researchers at
the University of British Columbia and Vancouver Coastal Health
Research Institute aims to reduce the 10 per cent failure rate in hip
replacements and make repeat replacements and other joint repairs
obsolete within 10-15 years. With $1.5 million over five years in
funding from the Canadian Institutes for Health Research, a group of
seven UBC scientists will explore how stem cells – the body’s
"master cells" that can reproduce and develop many mature
functional cells – can be used to regenerate bone cells to better
secure artificial joints and other bone replacement structures. Fluorescent shark A research team of the National Oceanic and Atmospheric
Administration (NOAA) has returned from a Gulf of Mexico cruise with
footage of deep-sea predators and has discovered the world’s first
shown fluorescent shark. Operation Deep Scope, tested a new deep-sea
camera system called Eye-in-the-Sea and returned with data that may
prove useful in biotechnology, genomics and energy development. The
exploratory expedition, led by the Harbor Branch Oceanographic
Institution, also brought back data to support a new theory about how
some animals may use polarised light to find prey, according to an
NOAA release. — PTI
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Frequent road accidents with automobiles due to rash
driving and Congestion on the roads as well as price hike of fuels
will make mass transit systems like trains more suitable if they can
be made more convenient, comfortable, reliable, cost effective and
safe. But problems with the conventional double guideway trains such
as derailment, head-on collisions with trains and other type of
vehicles on the tracks as well as on the intersections are proving
major blocks towards providing a safe travel mode to the people. A
transit system which can get rid of environmental pollution and
congestion caused by auto traffic is the demand of hour.