Zero emission vehicles
By Antarpreet Singh
ELECTRIC vehicles had been out of limelight for years. In the past few years, however, there has been a renewed interest in electric cars due to air pollution and global warming caused by the exhaust emissions of fuel driven vehicles.

Gravitational telescope
Dr Nataraja Sarma
WERE it not for that invisible force field called gravity, all of us animals, the water in the rivers and the sewers and everything else would be floating around in terrible confusion.

Research for longevity
By K.K. Sarin
AVERAGE life span has improved considerably during the last 50 years. At present, it is 64 years on an all-India basis.

New Product and Discoveries

Zero emission vehicles
By Antarpreet Singh

ELECTRIC vehicles had been out of limelight for years. In the past few years, however, there has been a renewed interest in electric cars due to air pollution and global warming caused by the exhaust emissions of fuel driven vehicles.

Several auto giants like Toyota and General Motors have initiated research projects on the electric cars in the last few years. General Motors successfully developed in 1993 a zero emission vehicle (ZEV) model named “Impact” using conventional lead acid batteries. Although this model offered a breakthrough mileage per charge and much superior performance compared to earlier ZEVs, GM decided not to go in for mass production and continue further research.

Toyota has also developed a new generation ZEV with the active collaboration of Matsushita Electric. The model Toyota RAV4L hit the market last year. This ZEV carries a 95 Ampere Hour, 12 volts nickel metal hydride battery which gives the car a mileage close to 200 km per charge. Such a high mileage has been eluding auto scientists for long. The car can attain a maximum speed of 125 kms/hour. The battery can last 1000 charging cycles which is equivalent to 2,00,000 km run.

History it seems, is repeating itself. Electric cars were a popular choice in the early years of this century. The first electric car built in 1892 could run 40 miles per charge at a speed of 16 miles an hour. By the turn of century, electric became choice of elite. Battery charging at home was considered much more refined than pumping oil or gas.

Electrics offered a clean and most reliable solution to horseless transportation but the popularity of old generation ZEVs was short-lived due to poor battery technology which resulted in poor charging accompanied with high power loss and limited driving range per charge.

Although several serious attempts were made all over, to have a low power loss charging (including a mercury vapour rectifier technology developed in 1906 which provided a quick low loss conversion of AC to DC) the electrics never recovered and lost the race to legendary Henry Ford whose innovative engineering ideas brought a revolution in the field of fuel driven vehicles.

After almost 100 years auto engineers are again exploring ideas to bring these ZEVs back on the road. Public in general is as curious about electrics as it was a century ago. Environmentalists are very much excited with the idea of having ZEVs replacing fuel driven vehicles gradually.

At the government level also there have been initiatives in the USA to encourage use of ZEVs. Under the 1990 emission control programme at least 2% of the new car production in USA this year, from an auto manufacturer must be in ZEV category. In 2003 the ZEV production limit would be 10% in Japan, Toyota has targeted a production of 10,000 ZEVs this year.

Think of it — owning an electric car. Sounds great — on need to get a pollution control certificate for your vehicle, every six months. You would only require a quich rectifier charging facility at home. You could put your ZEV on charging probably twice a week or so.

Gravitational telescope
Dr Nataraja Sarma

WERE it not for that invisible force field called gravity, all of us animals, the water in the rivers and the sewers and everything else would be floating around in terrible confusion. Just as Mother Earth pulls everything towards her, restoring a certain order, all massive bodies pull towards each other through the gravitational force.

Every force field has waves associated with it and appropriate techniques can observe them. The electrostatic and magnetic attraction and repulsion that we met in school are associated with electromagnetic waves and these waves enable us to see light, listen to music through radio waves, to be X-rayed for broken bones and be cured of cancer by gamma rays.

Unfortunately the force of gravity is far weaker than all the other forces in nature and is observed only when extremely massive objects like the sun or the earth are involved. For instance, we notice the gravitational pull of the moon because of the tides and it is the gravitational force that makes the moon go round the earth and the earth to go round the sun. Extremely sensitive detectors have, however, been made that can feel that gravitational attraction between heavy objects assembled in the laboratory.

Gravitational waves connected with the force of gravity have not yet been detected and neither have theoreticians been able to include gravity into a comprehensive description of the forces of nature. Einstein made the first attempt to describe these waves in his General Theory of Relativity. He included time as a fourth dimension added to a three-dimensional world and defined gravitational waves to be “disturbances in the curvature of space-time caused by motions of matter.

In other words, when a star moved in the four dimensional “graph-paper” that contained if, the graph paper itself developed a kink, a kink that weakened as it travelled across the universe. He reasoned that particles of light, photons, had no mass and should not be affected by the force of gravity.

But the kink in space-time would pull or push them out of their path. Sure enough, accurate measurements made on the bending of light by the gravity of a large mass during the total solar eclipse of 1919 by a team led by Sir Arthur Eddington confirmed Einstein’s arguments.

The space-time wrinkle makes distance expand and shrink by an extremely small distance. Experiments were, therefore, set up simultaneously in the USA and Australia during the 1980’s to observe these small variations in the position of large masses hung inside a high vacuum but no significant evidence for gravitational waves was obtained.

When a system like a star emits gravitational waves. Its total energy and so its mass should decrease. Such a decrease was seen around 1976 by astronomers looking at PSR 1913+16, a binary pulsar. The frequency of radio pulses from this doublet was slowing down by 75 microseconds every year, agreeing with calculations that pictured the two neutron stars as spiralling towards each other and losing energy by radiating gravity waves.

Astronomy has advanced over the centuries from observations by the naked eye to telescopes. After World War II, the bandwidth of these instruments greatly widened to cover the range from radio frequencies to the infra-red, X rays and gamma rays. Yet so far they have been confined to the electromagnetic spectrum.

Gravitational waves have the advantage over electromagnetic waves in that they are not absorbed by any obstacles. The information they carry is, therefore, available to the entire universe, as long as they can be deciphered. Astronomy based on gravity waves would, therefore, show us a whole new cosmos.

Black holes, supernovae and neutron stars cannot only be identified but their positions and distances can be computed. This in turn will take us back to the birth and history of our universe and forward to our final end. New discoveries may lie in outer space that only gravitational waves can open. For instance, a black hole has a certain frequency of vibration that depends on its shape and mass as well as its rotation. Gravity waves spun off from the black hole will tell us of these details.

A new generation of instruments is being developed at laboratories all over the world to detect gravitational waves. The problem is that the displacement of objects due to gravity waves is extremely minute.

An explosion involving ten times the mass of the sun which occurred ten billion light years away would move objects on this earth by less than a millionth of a millimetre! Only laser based techniques can see such small movements. If and when they are detected, gravity telescopes will take a new look at the distant universe. A number of countries are cooperating in a joint venture to build such devices.

One outstanding example is LIGO, or Laser Interferometer Gravitational waves Observatory. LIGO will detect gravity waves and measure their characteristics such as their velocity and their interactions. Once this is done, LIGO will monitor the development of black holes in the universe and the way they interact with other black holes. Supernovae and other cataclysmic phenomena will also be observed.

The instrument is an updated version of the classic Michelson-Morley interferometer. Cubes with finely polished and highly reflecting surfaces are hung on two arms of a cross, each arm extending to more than four kilometres. The arrangement is enclosed in very high vacuum inside a vibration-free box. This minimises the chance of stray gas molecules and vibrations due to the movement of cars and other heavy things affecting the instrument. The apparatus will be the world’s largest evacuated chamber when completed.

A laser beam is split to enter each arm of the cross and is reflected many times between the suspended cubes. The two beams are then recombined and adjustments made so that they interfere and cancel each other out. A very small movement between the cubes in each arm caused by a gravity wave will change the phase of the laser waves and cause an interference pattern. The variation of this pattern as the gravity waves goes through the apparatus is then correlated with a particular type of heavenly catastrophe.

As gravitational waves from distant stars would appear uniformly over out planet, two LIGO instruments are to be installed in the USA, separated by more than 3000 kilometres, along with one in Italy and perhaps more installations in the United Kingdom, Japan and Australia. All these laboratories will be time coordinated so that effects due to local disturbances like earth tremors are filtered out.

Gravity wave patterns have then to be coordinated with the information from optical and radio telescopes to confirm the conclusions that may be drawn from the LIGO telescopes. The new gravity astronomers who now follow the pioneering effects of Galileo are confident that they can, with this technique, identify catastrophes in the distant universe which took place, perhaps a billion light years ago and away, huge explosions like clashing neutron stars, merging black holes and imploding stars. (PTI)

Research for longevity
By K.K. Sarin

AVERAGE life span has improved considerably during the last 50 years. At present, it is 64 years on an all-India basis.

In Chandigarh and its satellite towns, it may be more. There are a good number of persons past the age of 70, still going strong.

In America, the average life span is 74 years.

Research has been going on the world over to prolong life span of living beings progressively. In humans, the nucleus of each cell holds 23 pairs of chromosomes, containing about 100000 genes. Some genes promote longevity. Their identification and mutation helps enhance life.

It has been observed that earthworms with the mutant gene lived 50% longer, with delay in the process of ageing.

Through selective breeding or genetic engineering, researchers have been able to raise animals with extended life spans.

According to historian Thomas R. Cole, in the last 200 years the social and biomedical worlds have thought of old age as only an engineering problem to be solved or at least ameliorated.

Cloning researchers are reported to have found a way to rejuvenate dying cells and are hopeful to produce genetically engineered calves that carry a “fountain of youth” gene, through nuclear transfer process.

British scientist Ian Wilmut and his team, cloned Dolly, an identical genetic copy of a sheep, in July, 1996, by taking a mammary gland cell from a six year old sheep, nucleus of egg-cell from another sheep and combing the two with a jolt of electricity.

The combined cells acted like a fertilised egg cell. The new developing embryo was implanted into a third sheep. A few months later, Dolly was born, living and breathing, an exact genetic copy of the first sheep.

It was a revolutionary achievement which was recognised worldwide. It stirred the scientists elsewhere to research further.

There was an anticipation that genetic copies of large mammals, including humans, could be created in future likewise.

On ethical consideration, it was debated as undesirable and unnatural. But once discovered, cloning was difficult to be checked like nuclear technology, with or without CTBT.

Last month, Japan reported cloning of a pair of calves. On its heels, scientists in Hawaii have turned out more than 50 carbon-copy mice by a more reliable coloning technique, using an injection method to transfer genetic material from adult mice to an empty egg.

Mouse is the most commonly used animal in biomedical experiments. The genetically identified copies of the same could speed up research in fundamental biology and every branch of medicine and drug development.

Cattle and pigs could be programmed with human genes to mass-produce proteins essential to treat illnesses like diabetes and Parkinson’s and halt the ageing process — a boon for good health and longevity.

Run flat? Try driving flat

By all accounts, run-flat tyres are helping hordes of drivers get home on time. The downside, however, is that the punctured tyre still must be replaced. Now Uniroyal Tyre, of Greenville, South Carolina, is reviving an older but better idea: a tyre that seals itself when punctured.

The idea has two advantages: The self-sealing tyre never needs repair, and it is less expensive than a run-flat. The downside: The resealing mechanism is ineffective against a slashed tyre of sidewall puncture.

The tyre utilises a gummy sealant under the treads. If the tyre is punctured, the sealant fills the gaps around the intrusion, such as a nail, preventing air from escaping. When the object is removed, the sub-stance seals the hole. In the past, this self-sealing system had only marginal effectiveness in wet weather, and also became less adept as the tyre aged. But, says Uniroyal, these sticky issues have been resolved with a new polymer-based sealant.

Popular science gave it a try by driving over a nail-studded block of wood at about 25 miles per hour. Though the block kept banging around the wheel well, no air was lost.

Beetle to ward off beetle

Crop scientists have used a chemical substance (Pheromone) found in beetles for the first time to fight beetle menace which affects groundnut production every year.

They have extracted a unique pheromone from female beetle Holotrichia consanguinea that has the ability to attract both sexes, according to the 1997-98 annual report of the Indian Council of Agricultural Research (ICAR).

The scientists found that pheromone treatment in farms around Jaipur not only reduced beetle population but also damage to groundnut plants which came down from 60-80 per cent to 15-20 per cent.

The extracted pheromones in four to six dispensers were kept for three days on a few selected trees which were pre-sprayed with insecticides.

Attracted by the pheromones, beetles in large numbers fed on insecticidal foliage and died while untreated trees had few beetle visitors.

The method pruned the use of insecticides by half to three-quarters, since trees within a radius of 20 metres of the treated ones were left unsprayed, the report said.

Conventional beetle fighting methods involve either use if insecticidal sprays which is not ecofriendly, or a dense tree cover which makes the process difficult. Biological control through worms or fungus is inefficient, it added.