SCIENCE & TECHNOLOGY

Power from rice straw
N.S. Grewal

It is a good news that rice straw is to be used as fuel for the generation of electricity in rural Punjab which would help in controlling the atmospheric pollution of the environments due to its burning.

DNA tracking to fight ivory trade
Steve Bloomfield

A scientific breakthrough has been heralded as a potential saviour for tens of thousands of elephants hunted for their ivory. Researchers have devised a genetic map of Africa’s elephants which — for the first time — has enabled investigators to pinpoint the exact region where a shipment of ivory originated.

Energy-saving tips
Jagvir Goyal

Today, almost everything runs on electricity. Life gets thrown out of gear on power failure. At the same time, its demand is outstripping the supply. Result is that electricity is becoming dearer and costlier. For an individual, electricity saved is money saved. For power producers, electricity saved is electricity produced.

Prof Yash Pal

Prof Yash Pal

PROF YASH PAL
THIS UNIVERSE 


 


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Power from rice straw
N.S. Grewal

It is a good news that rice straw is to be used as fuel for the generation of electricity in rural Punjab which would help in controlling the atmospheric pollution of the environments due to its burning.

Punjab roughly yields 100 million tonnes of rice straw annually which can produce 108mw of electricity when utilised fully. The project to be run by Punjab Biomass Power (PBP) in a joint venture of Ermaco Energy Systems, Gammon Infrastructure Projects and Archean Granile.

The first plant will become operational within two years at the cost of Rs 55 to 60 crore.

I, as a biogas energy expert, have certain reservations about its feasibility because similar projects were initiated earlier also in field of biogasification and about 120 community biogas plants were installed in rural areas of Punjab incurring crores of rupees by the Department of Agriculture Punjab funded by the Ministry of Non Conventional Energy Sources (MNES), Government of India. Majority of such biogas plants failed due to non-cooperation of the villagers for contribution of dung to the plants within one or two years of installation and hardly any community biogas is operational at present except one in Jalandhar district which runs with the special effort of the village panchayat. There was nothing wrong with the technology but failed due to non-cooperation of the villagers.

In the present case the difficulty would be that the paddy crop is harvested in the months of September and October and the next crop, that of wheat, is to be sown before 15th of November in the same fields. There is hardly any time with the farmers for collection of paddy straw from their fields and selling it to PBP at reasonable cost, because it involves labour and tractor trolley for the carriage. It is advisable that the PBP should collect the rice straw with their own labour and carriage system after compensating the farmers within limited time otherwise the farmers will resort to burning of the straw which they consider as the easiest method of disposal without caring for the environment.

Agricultural experts recommend that the paddy straw be ploughed in the fields because the straw is a rich source of organic manure, but the decomposition paddy straw require lot of time and require 3-4 disc harrowing of the fields even then undecomposed straw gives lot of trouble while sowing wheat with the seed drill. This process requires lot of diesel for running the agricultural machinery which involves cost to the farmers. The shortage of time and money force the farmer to burn it easily.

The water table of Punjab groundwater is going down and down every year and the Punjab Government is emphasising for diversification and recommending other crops requiring less watering for sowing. Therefore area under paddy crop is decreasing every year which would cause shortage of paddy straw in future for the power plants. Diversified crops like maize, moong and other crops will not have any crop residue for running the power plant, because it would be utilised as a fodder for the cattle.

If I remember that Energy School at P.A.U. got one power plant installed by using paddy straw as a fuel near Sirhind (Patiala district) in eighties and fate of that plant is not known now, might have closed down and the reasons for its failure would prove good guideline for PBP planners to save new power plants from similar trouble.

Keeping all these points in view PBP is suggested to overcome the difficulties by suitable method for the success of the power plants. It is also recommended that only one such power plant be installed to start with at a suitable place where sufficient fuel (paddy straw) would be available for running the boilers. Its performance to generate electricity be studied for a year or two before the installation of remaining power plants. This would be more useful for the planners to utilise money in a better way and hold better chances for their success. On a paper every project provides a rosy picture without knowing the teething problems later

The writer is a former Professor & Head, Civil Engineering, and Chief Engineer, Punjab Agricultural University, Ludhiana

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DNA tracking to fight ivory trade
Steve Bloomfield

A scientific breakthrough has been heralded as a potential saviour for tens of thousands of elephants hunted for their ivory. Researchers have devised a genetic map of Africa’s elephants which — for the first time — has enabled investigators to pinpoint the exact region where a shipment of ivory originated.

The advance could not be more timely. Eighteen years after the Convention on International Trade in Endangered Species (Cites) brought in a global ban on the sale of ivory, the illegal trade has reached the highest levels ever reported.

The price of a kilogram of ivory was $100 in 1989, when the ban was introduced. In the following few years it fell to as low as $10. But by this year the price rocketed to $850 making the largest tusks worth thousands of dollars. For some crime syndicates, ivory has become more lucrative — and easier to move — than illegal drugs. At least 23,000 elephants were killed for their tusks last year.

“These are urgent problems,” said Dr Samuel Wasser, the director of the University of Washington’s Centre for Conservation Biology, where the DNA methods have been pioneered. “Poaching is the worst it has been in history. There is an enormous market for ivory in the Far East. There is an insatiable demand.” The greatest difficulty for the scientists was working out how to extract the DNA. The ivory has to be reduced to dust, but previous attempts by other scientists to powder it through heat had destroyed the DNA. The researchers at the University of Washington borrowed a method used by dentists to grind teeth to dust. Using a machine that freezes the ivory at -240C, they were able to make it brittle enough to be turned into powder, and the DNA was preserved.

By collecting elephant dung from across Africa and extracting the DNA, the researchers produced a map detailing the genetic make-up of the continent’s elephants. Once the DNA of the ivory was known, Dr Wasser simply compared it to the map.

The theory was put to the test when his team studied the largest-ever haul of illegal ivory. More than 500 tusks had been seized in Singapore in 2002. Some 37 were tested, and all matched the genetics of elephants from Zambia and its surrounding savannah. Zambia’s director of wildlife has since been replaced, and laws on ivory smuggling have been tightened.

Similar pioneering DNA methods have been used to prove the true provenance of seal penises, thought by some to be a powerful aphrodisiac. Geneticists who travelled the world buying seal penises found that one in three had come from a different animal.

By arrangement with The Independent, London.

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Energy-saving tips
Jagvir Goyal

Today, almost everything runs on electricity. Life gets thrown out of gear on power failure. At the same time, its demand is outstripping the supply. Result is that electricity is becoming dearer and costlier. For an individual, electricity saved is money saved. For power producers, electricity saved is electricity produced.

The situation demands that every citizen should save electricity wherever possible. Indian bureau of Energy Efficiency also suggests many tips on saving electricity and reducing electricity bills. Here are a few of them:

LIGHTING:

1. As far as possible use task lighting, which focuses light where it’s needed.

2. Dirty tubelights and bulbs reflect less light and can absorb 50 per cent of the light; dust them off regularly.

3. Compact Fluorescent Lamps (CFLs) convert electricity to visible light up to 5 times more efficiently than ordinary bulbs and save about 70 per cent of electricity. A 15-watt CFL produces same amount of light as a 60-watt incandescent bulb.

4. Ninety percent of the energy consumed by an ordinary bulb goes off as heat rather than visible light.

ROOM AIRCONDITIONERS:

1. Fans cost about Rs. 0.30 paisa per hour while ACs cost about Rs. 10.00 per hour. So use ACs as sparingly as possible.

2. Plant trees and shrubs around your house to keep the hottest sun off. Shading house’s windows and walls may increase the efficiency of ACs by as much as 40 per cent.

3. Each degree above 220C increases AC efficiency by 3 to 5 per cent. Set the thermostat of AC at 250C to have best comfort at least cost.

4. Clean the air-conditioner filter every month. A dirty air filter reduces airflow and may damage the unit.

REGRIGERATORS:

1. Refrigerator motors and compressors generate heat. Allow enough space for continuous airflow around refrigerator.

2. A full refrigerator is fine, but be sure to allow adequate air circulation inside.

3. When it’s dark, place a lit flashlight inside the refrigerator and close the door. If light around the door is seen, the seals need to be replaced.

4. Keep the refrigerator away from all sources of heat, including direct sunlight, radiators and appliances such as the oven, and cooking range.

5. Allow hot and warm foods to cool and cover them well before putting them in refrigerator. Refrigerator will use less energy and condensation will reduce.

6. Think of what you need before opening refrigerator door. You’ll reduce the amount of time the door remains open.

WATER HEATERS:

1. By reducing the temperature setting of water heater from 600C to 500C, one could save 18 percent of the energy used at the higher setting.

2. To help reduce heat loss, insulate hot water pipes, especially where they run through unheated areas. Never insulate plastic pipes.

MICROWAVE OVENS:

1. Use Microwave oven. It saves up to 50 percent on your cooking energy costs for a regular oven, especially for small quantities of food.

2. Microwaves cook food from the outside edge toward the centre of the dish, so if you’re cooking more than one item, place larger and thicker items on the outside.

ELECTRIC KETTLES:

1. Use an electric kettle to heat water. It’s more efficient than an electric cook top element.

2. When buying a new electric kettle, choose one with automatic shut-off button and heat-resistant handle.

3. It takes more energy to heat a dirty kettle. Regularly clean your electric kettle by combining boiling water and vinegar to remove mineral deposits.

COMPUTERS:

1. Turn off your home/office equipment when not in use. A computer that runs 24 hours a day, for instance, uses — more power than an energy-efficient refrigerator.

2. If your computer must be left on, turn off the monitor; this device alone uses more than half the system’s energy.

3. Set computers, monitors, and copiers to sleep-mode when not in use to cut energy costs by approximately 40 per cent.

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PROF YASH PAL
THIS UNIVERSE 
Is there any funda of white holes?

I have put in the above question as received. Till five years ago I did not know the meaning of the word funda. There was no such word in any dictionary. Finally I had to ask some young students. They were amazed at my ignorance. When they started talking of fundamentals of physics and chemistry, I realised that funda is short for fundamental, implying basic laws, even scientific reasons.

So here is the “funda” behind the concept of white holes. Before we talk of white holes, which probably do not exist, it might be useful to recount the science that led to the prediction of black holes.

Following the theory of gravity, particularly Einstein’s theory of relativity, it is easy to extrapolate that if the mass is large enough and the distance from the center of that mass small enough then even light will not be able to escape from with that mass.

The mass will then become invisible to the outside world. In principle a black hole can have a very small mass if the radius within which it is confined is also very small.

One normally speaks of astronomical black holes that are produced through evolution and collapse of massive stars. This could be the ultimate fate of most stars that have a mass several times the mass of the sun. Such stars collapse after the energy generating fuel inside is exhausted.

Even the Pauli exclusion forces, or the degeneracy pressure, of electrons or nucleons cannot resist their inward gravitational force. In layman’s language, the structural strengths of atoms and nuclei fail under the assault of the overwhelming gravitational pressure.

Such black holes have been discovered through their gravitational effect on an accompanying star in a binary system or on many stars orbiting a location that is otherwise invisible. If one finds that the required mass of the object providing the gravitational forces is higher than several solar masses we come to the conclusion that it must be a black hole.

We do not see anything of what is happening inside the invisible object but we can infer its existence from what its presence does to the outside. Black holes have been found amongst separated star systems and also in the centres of galaxies, including our own.

Black holes were predicted much before they were actually observed — or inferred. Equations of relativity, like Newton’s equations, are equally valid if the direction of time is changed.

Equations that predict the formation of a black hole could be arbitrarily changed to move backwards if we change the direction of time.

Then we could make a theory in which a hole, instead of sucking in every thing, including light, within itself, would spew things out. While a black hole does not allow exit, such a hole would bar entry.

Therefore we could be calling it a white hole. There is not much more to this story.

Incidentally you would be able to think of creating a white hole only if you can also destroy a black hole!

Both these acts require time reversal.

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