|SCIENCE & TECHNOLOGY|
A power station on your roof
Plastic pipes for water management
Making Einstein youth friendly
And now plantoons!
New products & discoveries
A power station on your roof
Dr Steven Cutts assesses the prospects of using the colossal power of the sun to heat our homes and run our household appliances.
Not since the oil crisis of the 1970s has energy generation been such a hot political issue. Since the US-led invasion of Iraq the price of oil has soared, and fears that the world’s fossil fuels may be exhausted within decades have accelerated serious discussion about the prospects of harnessing the natural energy of wind and tides. Amid the excitement a few sober realists insist that nothing pumps out electricity so abundantly and cleanly as nuclear power plants.
But what about solar power? However bleak and windswept, just about every place on earth manages to catch a bit of sun, and it has long been known that solar power can be converted directly into electricity using what are called photovoltaic cells. When I was a kid there was a passing craze for water-heating solar panels strapped to the side of roofs. It didn’t last long because the amount of energy saved was negligible and the reduction in electric bills peanuts. But science and technology have come quite a way since that time.
Photovoltaic cells were invented in the 1950s. Made from two sheets of silicon they produce electricity whenever sunlight falls on them. Early models were hopelessly inefficient but today’s solar cells convert about 15% of the sun’s power to electricity and it may not be long before solar panels covering your roof will power the refrigerator and TV as well as heat your home and water.
Present-day power stations transmit their output through very long cables —and about a quarter of the power is lost in the form of heat by the time it reaches homes and factories.
By contrast, a solar power station on your roof would deliver all its energy directly into your home.
Scientists have calculated that the sun could produce around 10,000 times more energy than the earth presently consumes.
By laying photovoltaic cells across just one small part of the sun-drenched Sahara desert, we could make enough electricity to satisfy the entire world. So why don’t we?
Since the dawn of the nuclear age, fantastic new ideas for tapping energy sources have been two a penny. Few of them have produced more than hot air. Supporters of so-called "clean" energy tend to talk in terms of how many houses their power schemes could supply. But only about half of our electricity is consumed by homes and the figures quoted are usually for power output in optimum conditions. When the sun is obscured and the air is comparatively still, solar panels and wind farms contribute next to nothing in the way of usable energy. And that is most of the time.
That’s not to say they haven’t a future. In the 1970s photovoltaic cells were confined to spacecraft and other fabulously expensive technology. But the cost of their manufacture has plummeted by more than 90% since then and now the technology is on the cutting edge of viability. Within another 10 years it could be genuinely competitive.
Part of the impediment to the widespread adoption of photovoltaic cells is the low cost of electrical power in the Western world. No matter how passionately green their philosophy, few people can afford to double their electricity bills for the good of the planet. Some proponents of alternative energy openly bemoan the present cheapness of mainstream power and even hope for a crisis that causes others to rush to their support.
Admittedly a few of the people stridently promoting green doctrines do go ‘over the top’, but that doesn’t mean nobody takes them seriously.
Global warming and West Asian conflict have encouraged some far-seeing governments and institutions to try introducing alternative sources of power.
The Japanese, for example, have built over 500,000 new homes with photovoltaic cells on their roofs. If they can maintain the current rate of production over several decades, solar power may begin to reduce their dependency on imported fossil fuels. Because Japan has virtually no indigenous sources of power, its government is spending the equivalent of $500 million a year on photovoltaic technology.
Coating your roof with solar cells might once have cost a small fortune and made your house look like a space station. Not any more.
The latest solar-panelled roofs are easier on both eye and pocket. Presently they will set you back about seven times the annual cost of your mains electricity. In that time your investment will have paid for itself anyway, but since photovoltaic cells actually produce more power than you are likely to consume, you might even sell the excess to a local business and show an annual profit as the owner of a miniature power station.
The photovoltaic roof could give you strategic and economic independence.
Unaffected by energy industry disputes, the owner of a privately powered home would be a disinterested observer of any military adventures contrived to safeguard energy supplies.
It’s an agreeable prospect, so why aren’t we already making it a reality? Because photovoltaic cells can’t produce power at night they’re not going to cause the closure of conventional power stations although they could reduce the fuel needed for consumption during daylight hours and thus the amount of air pollution emitted. And why invest huge sums of money buying photovoltaic cells now when perhaps 10 years on we shall be able to buy them much more cheaply?
What science needs to give us is a photovoltaic cell virtually indistinguishable from a conventional roof tile, having the same rainproof and heat-insulating properties and capable of producing sufficient power for more than one home.
When that is achieved surely no one will want any other form of roofing material, especially if enlightened governments offer the incentive of lower tax on homes equipped with it.
Plastic pipes for water management
Reinforced cement concrete (RCC), Galvanised iron (GI), Asbestos cement and Cast iron (CI) are the traditional pipes being used to carry water and all types of fluids.
However, these conventional pipes are most susceptible to corrosion and bacterial buildup whereas plastic pipes do not suffer from these problems. Plastics are inherently immune to both external corrosion and internal pipe corrosion.
The chemicals commonly generated in sanitary sewers also do not affect the plastic pipes either. Plastic pipes’s smooth inner surface provides great resistance to corrosive biofilm. Moreover plastic pipes do not deteriorate, nor they break down under attacks from bacterial or other micro organisms.
Plastics first developed in the early 20th century, the use of plastics has has been exceptional for management of a scarce commodity like water.
The properties (good strength to weight ratio, tough, durable, non toxic, easy process ability, rust proof, reusable and recyclable) of plastics, make them suitable to replace the metallic and cement pipes. Plastic pipes are manufactured from polyvinyl chloride, polyethylene and polypropylene for different applications.
Polyvinyl Choloride PVC pipes possess excellent technical qualities. In a range of application from potable water to sewerage, PVC pipes are able to fulfil all the demanding specifications. PVC pipes are competitive in terms of cost, easy to instal and require low maintenance, PVC is light in weight, allows long sections of pipes to be made, minimising the number of joints which reduces the cost of assembly.
They are having good chemical resistant properties and can be used above or below ground for transport of all types of fluids, including drinking water. These pipes are also used as ducking in the telecommunication industry for carrying cables and wiring.
UPVC unplasticised poly vinyl chloride pipe is one of the most important developments of last few decades and has changed the entire scenario of the construction industry.
Now we find UPVC conduits for all electrical fittings, rigid UPVC plumbing pipes, RPVC fittings and LLDPE water storage tanks. UPVC pipes are corrosion resistant and immune to surface corrosion.
They are having good chemical resistance and not attacked by low or high concentration of acids, oxidising agents, alkalis, oils, fats and halogens. They also possess low thermal conductivity due to which they maintain uniform temperatures in transporting fluids.
They are non-toxic, biological resistance, maintenance free and self extinguishing.
They can also be joined by various jointing methods like heat fusing, threading, fanged and compression fitting.
Rainwater harvesting (RWH) is the activity of direct collection of raindrops for reuse in containers or recharging in to the ground for withdrawal later.
RWH conserves and augment the storage of ground water, water table depletion, improve the quality of ground water, arrest sea water intrusion in coastal areas, avoid flood and water stagnation in urban areas.
PVC pipes are being used as channels all around the edge of a slopping roof to collect and transport rainwater to the storage tank. Half round PVC pipes can also be used as gutters for the RWH system.
Energy is one of the most fundamental parts of our universe and integral of our daily lives and is being consumed at every moment by all, albeit, in different forms. Its conservation is very important and essential. Use of UPVC pipes can result in substantial conservation of energy. Being lightweight over conventional material like RCC, cast iron and GI pipes (one fifth the weight of steel or cast iron) thus saving the transporation cost considerably and smooth surface of pipes also reduce the frictional losses.
Keeping in view the dramatic
reduction in installation cost, corrosion free, bacterial resistant
and other functional advantages like chemical resistant, easy
maintenance & jointing, low weight, energy conservation, low
transportation cost and versatility of design makes the PVC pipes
ideal for water management.
Making Einstein youth friendly
Bicycle stunts, rap music and modern dance — all in the name of Einstein. Hardly E=mc2, but 100 years after Albert Einstein published three seminal research papers which changed scientific thinking about the universe forever, physicians are conscious they must rebrand their shunned science to appeal to young people.
Einstein Year was launched in Britain this month at a youth driven ceremony at London’s Science Museum where a BMX stunt rider performed an "Einstein flip", said to be the first bicycle stunt to be designed by a physicist.
"There tends to be a knee-jerk negative reaction about physics — that it is boring and hard. What we are trying to do is change people’s perceptions," said Caitlin Watson of the Institute of Physics (IoP) in London.
"We want to show that physics is not about the stereotype of the mad scientist. Physicists are normal people doing normal things."
Rap artist DJ Vader has also been drafted in by organisers to rebrand physics as cool. His love song "Einstein (not enough time)" has been adopted as the theme tune for the year-long celebrations across Britain.
It is unlikely he will ever replace Einstein as the face of science. Einstein’s iconic image is known the world over.
"We remember (him) now mainly as an older man, the benign and unkempt sage on a poster and t-shirt," said Prof Martin Rees of Cambridge University.
"That’s surprising because his great work was well over by the time he was 40. At that time (1905) ... he was a nattily dressed young professor. In a way, the icon is rather different from the man who made these great achievements."
Some people say the celebrations marking Einstein’s annus mirabilis border on being irreverent.
"Of course, physics is a science used in
all kinds of applications in technology, the environment etcetera, and anything
we can do, even if it means dumbing down to enthuse young people about physics,
is surely excellent," said Rees. — Reuters
And now plantoons!
Boosted by the increasing popularity of scientoons among children, two scientists have started working on its detailed version — the "plantoons". Conceptualised in 1988 by Lucknow scientist Dr Pradeep Srivastava of the Central Drug Research Institute, "scientoons" (cartoons depicting various aspects and developments in science), was welcomed by science institutes all over the country.
Now, Dr Srivastava and Dr S P S Khanuja, Director of Central Institute of Medical and Aromatic Plants (CIMAP), have together conceived the idea of plantoons (cartoons based purely on plants), terming it to be "an off-shoot of the scientoons".
Dr Khanuja says: "The concept of plantoons was moved by us on January 15 this year during a Council for Scientific and Industrial Research (CSIR) programme for youth leadership at the CIMAP".
It is aimed at imparting better knowledge about plants among kids and encouraging them to take up science.
Young minds would be informed about plants through very simple ways under the garb of plantoons. They will know how plants, remaining stationary at a place grow tall, bear leaves, flowers and fruits and withstand heat, cold and rain.
Dr Khanuja said: "We can very easily make children understand the importance of plants through plantoons.
For instance, we can tell them about the
recent tragedy caused by the tsunami and how the mangrove forests saved some
areas from the natural calamity. Some of the communities in Andaman and Nicobar
islands stopped the mangrove from being cut which in turn saved them. We would
depict such immense importance of plants to human life and environment through
the plantoons." — UNI
products & discoveries
Astronomers have announced that they have a lead in the case of the missing disks. The report was presented by UCLA graduate student and Ph.D. candidate Peter Plavchan; his adviser, Michael Jura; and Sarah Lipscy, now at Ball Aerospace, to the American Astronomical Society meeting in San Diego. This lead may account for the missing evidence of red dwarfs forming planetary systems.
Red dwarfs (or M Dwarfs) are stars like our sun in many respects but smaller, less massive and fainter. Approximately 70 percent of all the stars in our galaxy are red dwarfs.
"We would like to understand whether these stars form planets, as the other stars in our galaxy do," said Plavchan, who leads this research investigation. Approximately half of all newborn stars are known to possess the materials to make planets. When stars are born, the leftover materials form what astronomers refer to as a primordial disk surrounding the star. From this primordial disk, composed of gas and small grains of solid material astronomers call "dust," planets can start to grow.
As these "planetesimals" grow by accreting nearby material in the primordial disk, they also collide with one another. These collisions are frequent and violent, producing more dust forming a new disk of debris after the star is about 5-10 million years old. In our own solar system, we see evidence everywhere of these violent collisions that took place more than four billion years ago — such as the craters on the moon.
Micromachines that are "alive"
In a Los Angeles laboratory, researchers have let loose scores of what amount to living micromachines. Dwarfed by a comma, each tiny device consists of an arch of gold coated along its inner surface with a sheath of cardiac muscle grown from rat cells.
With each of the muscle bundles’ automatic cycles of contraction and relaxation, the device takes a step.
Viewed under a microscope, "they move very fast," says bioengineer Jianzhong Xi of the University of California, Los Angeles (UCLA). "The first time I saw that, it was kind of scary."
Xi and his UCLA colleagues Jacob J. Schmidt and Carlo D. Montemagno describe their musclebots in the February Nature Materials.
Microcontraptions of this sort may someday make pinpoint deliveries of drugs to cells or shuttle minuscule components during the manufacture of other itsy machines or structures, Xi says. Variations on the same design could lead to muscle-driven power supplies for microdevices or laboratory test beds for studying properties of muscle tissue.
Eyeballs on microchip
North Carolina State University chemical engineers have discovered a way to construct new microscopic devices that can act like tiny factories for materials with potential for a wide variety of chemical and biological uses.
The NC State researchers, advised by Dr. Orlin Velev, assistant professor of chemical and biomolecular engineering, include undergraduate student Jeffrey R. Millman and graduate students Ketan H. Bhatt and Brian G. Prevo. They created different types of tiny particles that could eventually be used in everything from drug delivery to determinations of the presence or concentration of biological molecules.
Some types of new particles look like
microscopic eyeballs, but are really made of tiny particles of gold and latex.
Others look like billiard balls, but are slivers of gold, silica and colored
Q: Can earthquakes be predicted? Can animal behaviour provide some help?
A: If you look back in time, you would realise that significant progress has been made in the area of geology and geophysics. We have identified areas on the Earth that are earthquake prone, and can say with some certainty that they will be struck by an earthquake during next few decades. I know that this is not enough. What we want to know is the exact place where an earthquake of damaging intensity would occur and the exact moment it would happen. This looks like a difficult task at the moment. But the situation is not entirely hopeless; several indicators are beginning to emerge, including those connected with the behavior of animals just before an earthquake; these creatures respond to some precursor signals that we do not yet sense, or understand, sufficiently well. There is no reason this would not happen in coming years. In view of the advances in earth sciences, I can foresee that the capabilities of earthquake prediction would advance significantly during next few decades, even though it may never achieve perfection. We have to remember that while we can now measure so many more parameters about the atmosphere and the oceans, we still cannot predict with sufficient accuracy, the occurrence of tornadoes and cyclones.
The large number of interacting variables that impact these phenomena result in an astonishing degree of complexity. The best strategy is not to wait for extremely accurate predictions, but to design our habitats in a manner such that these, do not collapse when the Earth decides to shake.
Q: Can the capacity of the brain be increased in any way? Or is it pre-decided, depending upon the genepool that one comes from?
The capacity of the brain can be
increased if it is used more often. I have a feeling that the habit of
accepting a lot of things on faith, without inquiry, can produce a
mindset in which many processing capabilities of the brain first go to
sleep and then are eliminated. The brain grows through use. Remember
that honest intellectual inquiry and the spirit of questioning (rather
than simply learning by rote) are vital exercises for a brain. While
the memory bank is necessary, it is not productive without a high
capacity "processor". The programs and subroutines for the
"processor" are self developed and cannot be bought from
Intel or Microsoft