SCIENCE & TECHNOLOGY

Now wireless electricity
Parteek Bhatia

In this information age we all want to be connected, but none of us loves the cables that connect. Of course, rapidly growing wireless technologies — cellular phones, Wi-Fi, ID tags, Bluetooth, and many others — provide data connectivity. Wireless data are so pervasive that readers may wonder what is so difficult about providing a wireless power cord.

Waste disposal made easy
Jagvir Goyal

Kitchen sinks are generally provided with a 3 to 4 inch diameter waste outlet and a 2 inch dia waste pipe falling inside the floor trap to carry away the waste water from the sink. The pipe is either of GI or plastic and often gets off the waste outlet when the flow of water is fast. Generally, the waste outlets are provided with waste plugs used to retain the water in the sink for washing of dishes.


Prof Yash Pal

Prof Yash Pal

THIS UNIVERSE
I have heard about the suggestion of some scientists that by mining the abundant quantities of He3 on the surface of moon we can produce large quantities of energy very cheaply. What are the facts and how much of it is sheer nonsense?
One thing is certainly true. If someone gave us an enormous amount of helium-3, then through interaction of that helium with deuterons, nuclei of heavy hydrogen, fairly abundant in water, we could produce enormous amounts of energy.

Kids smarter than chimps
It’s official: Your toddler is smarter than a chimp, at least at some things.
A unique study comparing the abilities of human toddlers to chimpanzees and orangutans found that two-year-old children have social learning skills superior to the apes, researchers said on Thursday.

Livestock extinction
Farm scientists warned on Monday that hardy breeds of livestock vital for world food supplies were dying out across developing countries, especially in Africa, and called for the creation of regional gene banks to save them. In a report to a conference in the Swiss town of Interlaken, the experts said tough and adaptable animals were being ousted by others from richer countries that were more productive in the short-term but posed a longer-term risk for farm output.

 


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Now wireless electricity
Parteek Bhatia

In this information age we all want to be connected, but none of us loves the cables that connect. Of course, rapidly growing wireless technologies — cellular phones, Wi-Fi, ID tags, Bluetooth, and many others — provide data connectivity. Wireless data are so pervasive that readers may wonder what is so difficult about providing a wireless power cord. And one can transfer power as well as information by means of electromagnetic radiation; indeed, sunlight is the ultimate source of most of the energy we use.

Sunlight can be extraordinarily intense, but it is still barely enough: The sunshine falling on my laptop carries about 25W, about half of what is needed. By wireless communications standards on the other hand, sunlight is very bright. So, we cannot use it as wireless power.

But, if wireless power cord becomes reality, it would be really convenient for us to use our electronic gadgets like cell phones, mp3 players, laptop computers and household robots. Then the tangle of cables and plugs needed to recharge today’s electronic gadgets could be a thing of the past. The portable electronics gadgets will be capable of charging themselves without ever being plugged in and freeing us from that final, ubiquitous power wire.

For these reasons, scientists have tried to develop methods of wireless power transmission. While the idea may sound futuristic, it isn’t particularly new. Nicola Tesla proposed theories of wireless power transmission in the late 1800s and early 1900s. Tesla’s work was impressive, but it didn’t immediately lead to widespread, practical methods for wireless power transmission. Since then, researchers have developed several techniques for moving electricity over long distances without wires.

Various methods of transmitting power wirelessly have been known for centuries. Perhaps the best known example is electromagnetic radiation, such as radio waves. While such radiation is excellent for wireless transmission of information, it is not feasible to use it for power transmission. Since radiation spreads in all directions, a vast majority of power would end up being wasted into free space. One can envision using directed electromagnetic radiation, such as lasers, but this is not very practical and can even be dangerous. It requires an uninterrupted line of sight between the source and the device, as well as a sophisticated tracking mechanism when the device is mobile. Some exist only as theories or prototypes, but others are already in use.

The natural question arises in mind that “Is there any device which operates on wireless power?” Think about some time. The answer is Yes! And the product is electric toothbrush.

A team from Massachusetts Institute of Technology’s (MIT), Department of Physics, Department of Electrical Engineering and Computer Science, and Institute for Soldier Nanotechnologies (ISN) has experimentally demonstrated an important step toward accomplishing this vision of the future. The MIT team refers to its concept as “WiTricity” (as in wireless electricity).

WiTricity is based on using coupled resonant objects. A phenomenon that causes an object to vibrate when energy of a certain frequency is applied. Two resonant objects of the same resonant frequency tend to exchange energy efficiently, while interacting weakly with extraneous off-resonant objects. This concept is quite old and there are number of practical examples that indicate the usage of resonance objects.

Following steps indicate how the wireless electricity will be delivered:

1) Power from mains to antenna, which is made of copper.

2) Antenna resonates at a frequency of 6.4MHz, emitting electromagnetic waves.

3) ‘Tails’ of energy from antenna ‘tunnel’ up to 5m (16.4ft).

4) Electricity picked up by laptop’s antenna, which must also be resonating at 6.4MHz. Energy used to re-charge device.

5) Energy not transferred to laptop re-absorbed by source antenna. People/other objects not affected as not resonating at 6.4MH.

Although the system now works and transfers a useful 60 W of power over an impressive 2 m, there are still some important issues that need addressing. For example, of the 60 W of power transferred, ~5 W currently ends up as unintended radio radiation. This may not seem much as a proportion of the power transferred, but it still matter a lot for small power devices like cellular handset. The development team is hopeful that it can be reduced by improving the components and the design of the system. There may still be issues with loss of power and induced radiation caused by metal and other objects that happen to be lying around within the field. Although the preliminary experiments look promising and the resonant nature of the transfer should help to solve all the problems. So, in near future we will be wire-free and child will say to mother by looking towards lighted electric bulb. “Look Maa: No Wires”.

The writer is from the Department of Computer Science & Engineering, Thapar University, Patiala.

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Waste disposal made easy
Jagvir Goyal

Kitchen sinks are generally provided with a 3 to 4 inch diameter waste outlet and a 2 inch dia waste pipe falling inside the floor trap to carry away the waste water from the sink. The pipe is either of GI or plastic and often gets off the waste outlet when the flow of water is fast. Generally, the waste outlets are provided with waste plugs used to retain the water in the sink for washing of dishes. When the washing is over, the plug is pulled out and the water rushes through the pipe. If the pipe clamp is not fully tightened or has got rusted with time, the pipe goes off the waste outlet and free flow of waste water leaves the kitchen-maker cursing.

With the passage of time, the waste pipes begin looking ugly. No doubt, these are hidden from sight in modular kitchens but the problem remains.

Another problem specially noted in Indian kitchens is that the waste outlet often gets blocked by the leftovers of Indian food and has to be taken out either by hand or by using some pointed tool—something that Indian ladies hate to do.

To tackle this problem, a wonderful waste food disposer called Trash Masher has now been invented and is available at very competitive price. The waste pipe is replaced by this disposer by means of a special coupling supplied along with the disposer. The trash masher is then clipped to the coupling and is also connected to 220 volt mains. As soon as the trash masher is switched on and the waste plug is removed from the sink waste, the waste water carrying trash food is sucked by the trash masher, converted into a curry and flown into the floor trap.

The operation takes half a minute and the power consumption per month is negligible, say 2 to 3 units.

Trash Masher can be connected to a dish washer also. Egg shells, fruit peels, residues of vegetables and even small bones get crushed rather mashed and converted to flow able material transferred to the floor trap.

Three models of different sizes costing Rs. 5000 to Rs. 7000 are now available and a suitable one depending upon the size of kitchen sink or dish washer is chosen.

An indirect advantage of trash masher is that the waste food doesn’t keep lying in the waste basket for whole of the night, inviting insects and generating foul smell. It gets disposed instantly!

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THIS UNIVERSE
PROF YASH PAL

I have heard about the suggestion of some scientists that by mining the abundant quantities of He3 on the surface of moon we can produce large quantities of energy very cheaply. What are the facts and how much of it is sheer nonsense?

One thing is certainly true. If someone gave us an enormous amount of helium-3, then through interaction of that helium with deuterons, nuclei of heavy hydrogen, fairly abundant in water, we could produce enormous amounts of energy. In this reaction the products would be ordinary helium, namely helium-4 and a proton and nothing else — except for a lot of energy. This fusion reaction involves transfer of one neutron from deuterium to He-3, turning it to ordinary helium (He-4) and releasing the leftover proton from deuterium. No radioactive elements would be produced and most of the energy would come out as a charged beam of protons. Because of their charge these protons can be contained using electric and magnetic fields and their energy converted into electrical energy with high degree of efficiency. One cannot imagine a cleaner way of producing electrical energy. (However, some contamination would occur because mixing of He-3 and deuterons would also produce other reactions that would produce neutrons).

It is claimed that if the supply of He-3 were enough we could solve the energy problem of the planet once for all. (Mere 3 grams of He-3 would be enough to run a 1000 Mega-Watt reactor for half an hour, assuming 100% conversion efficiency). Heavy water is not that scarce. It forms 1 part in 7000 of all the oceans of the earth from which it can be separated without too much hassle. We already produce hundreds of tons of heavy water for our reactors. The problem is that the natural abundance of He-3 is extremely low (< .000137%). So where can we get sufficient amount of this valuable gas?

Origin of He-3

It is believed that stars, while going through their energy producing fusion reactions, synthesized most of the chemical elements below Iron. The heavier elements were produced in further evolution of stars resulting in supernova explosions, spreading their cooked material into space. This material formed the stuff of which the later stars and their planetary systems were constituted. It became clear therefore that those elements and isotopes that form important fuels for the fusion reactions within stars could not be produced within the stars. They would only be consumed. Therefore an idea developed that such low mass elements might be synthesized in early phases of evolution of the Universe. Detailed calculations involving cosmological considerations and nuclear reactions rates produced the remarkable result that cosmic abundances of He-4, He-3, Li-7 (isotope of lithium) and deuterium (H-2), come close to what is observed! This has often been taken as added evidence in favour of the evolutionary or Big Bang cosmology. On this count we might assume that He-3 we find all came from the Big Bang!

I find some other facts about He-3 rather interesting. It is a useful isotope for making neutron detectors. A slow neutron interacting with He-3 in a proportional counter would produce tritium (H-3) and a proton. He-3 is also of great interest scientifically, for its property of becoming a super fluid at temperatures very close to zero degrees Kelvin. It has provided insights for understanding the behavior of matter at extremely low temperatures when all thermal vibration disappears.

But let us come back to question of energy generation using He-3.So far the enterprise of mining for this gas has not been pursued because of its low abundance. It is interesting that the primary source available to scientists is a byproduct of the weapons programme of the two major powers. One of the ingredients used in hydrogen bombs is Tritium (H-3); this nucleus has one proton and two neutrons. Tritium is radioactive with a half-life of 12 years and decays into He-3. This He-3 has become the most abundant source for scientists. (The decayed Tritium in the bomb has of course to be replaced. It is estimated that about 150 Kg of He-3 has accumulated from the decay of tritium since 1955 in the US weapons programme. It is clear, of course this cannot be the route to power generation through the use of He-3!

Of late some excitement has been generated that we might try to collect the He-3 that might have accumulated in the regolith (crushed surface rocks and dust) of the Moon, the source being the rain of the Solar Wind over billions of years! Enormous amounts of rock would have to be mined to extract tiny traces of this gas. I admire and simultaneously dislike the adventurers who would so despoil the moon. It is not easy and may not be feasible. It would go against the Moon Treaty if only some major powers engage in these exploits. I wish it remains uneconomical. If the process becomes profitable there would be wars fought on the Moon. This is a venture that might be more damaging to the future of humanity if successful!

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Kids smarter than chimps

It’s official: Your toddler is smarter than a chimp, at least at some things.

A unique study comparing the abilities of human toddlers to chimpanzees and orangutans found that two-year-old children have social learning skills superior to the apes, researchers said on Thursday.

In one social learning test, a researcher showed the children and apes how to pop open a plastic tube to get food or a toy contained inside. The children observed and imitated the solution. Chimpanzees and orangutans, however, tried to smash open the tube or yank out the contents with their teeth.

European scientists gave a battery of cognitive tests lasting three to five hours separately to 105 two-year-old children, 106 chimpanzees and 32 orangutans over two weeks.

“Using these multiple tests allows us to pinpoint where are the similarities and where are the differences,” researcher Josep Call of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany told reporters.

The researchers believe their findings provide insight into the evolution of human cognition. People’s brains are three times larger than those of the closest primate relatives.

Chimpanzees and orangutans are among the great apes. Chimps are considered the closest genetic relatives to people, with orangutans a bit more distantly related. — Reuters

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Livestock extinction

Farm scientists warned on Monday that hardy breeds of livestock vital for world food supplies were dying out across developing countries, especially in Africa, and called for the creation of regional gene banks to save them.

In a report to a conference in the Swiss town of Interlaken, the experts said tough and adaptable animals were being ousted by others from richer countries that were more productive in the short-term but posed a longer-term risk for farm output.

“There is a livestock meltdown under way across Africa, Asia and Latin America. Valuable breeds are disappearing at an alarming rate,” Carlos Sere of the International Livestock Research Institute (ILRI) told the week-long gathering.

“In many cases we will not even know the true value of an existing breed until it has already gone,” declared Sere, Director-General of the Nairobi-based body which focuses on livestock research for development.

The report, from the United Nations Food and Agriculture Organisation (FAO), found that smallholders in poorer nations were abandoning their traditional animals in favour of higher-yield stock imported from Europe and the United States.

This growing reliance on a handful of farm animal species is causing the loss on average of one livestock breed every month in developing economies, the report said.

Holstein-Friesian cows with high milk yields, fast egg-laying White Leghorn chickens and quick-growing Large White pigs — all from the industrialised and more temperate countries of the North — were pushing out native species in the South. — Reuters



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