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Power in the wind
A ship made of ice?
Prof Yash
Pal
This Universe Trends
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Power in the wind As of March 31, 2005, India’s power system had an installed generation capacity of approximately 115,544.8 MW. Of the installed capacity, thermal power plants powered by coal, gas naphtha or oil accounted for approximately 69.4 per cent of total power capacity. Hydroelectric stations accounted for approximately 26 per cent and others (including nuclear stations and wind power) accounted for approximately 4.5 per cent. Wind energy is emerging as a strong source of power generation in the world. From a meager share of 0.2 per cent in the total installed capacity, share of wind power is expected to go up to 3 per cent by 2030. The countries like Denmark are meeting 20 per cent of their power needs from wind energy. Wind power exploration started in India way back in 1983-84 with the information of an independent Ministry of Non-Conventional Energy Sources (MNES). The MNES has promoted a market-oriented strategy which has led to commercial development of wind technology. The total wind power potential in the country’s 45,000 MW. Seven states in India (Tamil Nadu, Karnataka, Andhra Pradesh, Rajasthan, Maharashtra, Gujarat and Madhya Pradesh) have the highest potential and account for over 99 per cent of wind power installations in India. Five companies, Suzlon, NEPC, Vestas RRB, Enercon and GE Wind in the private sector are establishing wind farms in these seven states. Suzlon at the moment is the market leader with 42.8 per cent of the total installed capacity in India, followed by Vestas with 32 per cent and Enercon with 15.2 per cent of the total installed capacity in the country. The wind power is gaining popularity due to its clean generation process and falling per kilowatt hour cost of generation. According to US, the cost power kwh of wind power, which was $ 0.38 in 1980s had come down to 0.03 to 0.08 $ per kwh. Moreover, the carbon credits which are given to the clean energy generators under the Kyoto Climate Summit of 1997, are also an attraction to the power generators in this sector. The wind turbine generators (WTG) in the wind farms set up in Maharashtra, MP, Rajasthan, Tamil Nadu and
Andhra Pradesh have been purchased by some of the leading companies like Bajaj Auto, Tata Power, John Deere and Nirma. The power generated at the wind farms is supplied to the state electricity boards at a pre-agreed price ranging between Rs. 3 and 3.48 per unit. The state electricity board supplies the power to these industries at their factories after receiving the wheeling charges. If the power is not used by any owner, he may get the payment in cash after deduction of certain charges by the SEB as per agreement. Earlier, the WTGs installed by the power generating companies were 750 kwh to 1000 kwh capacity. But due to improvement in technology, the WTGs with higher capacity of 1250 kwh to 2000 kwh are being installed at the new sites. The cost of installing one WTG of 1000 kwh ranges from Rs 4.5 crore to Rs 5 crore. The companies provide support from installation to running, maintenance and management for 20 years. If tapped fully, India inc. can harness energy equal to 45 Bhakra dams from this environment-friendly source of energy. The writer is from NJSA Government College,
Kapurthala |
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A ship made of ice?
One of the secrets of World War II, just declassified, is that a project was almost approved in 1945 by Winston Churchill of building a giant ship made from ice! During World War II, such a ship was proposed and, if the war in Europe had not been drawing to an end, it might well have been built. And it would have been huge, weighing around three million tonnes at a time when the largest ship afloat, the “Queen Mary”, managed a mere 86,000 tonnes. The ship would have been over 2,000 feet (600 metres) long, with walls each 30 feet (9 metres) thick. As the ship was designed principally as a floating airfield, propulsion through the water would have been minimal (from a dozen outboard electric motors), supplied with power from diesel engines that would also have driven essential on-board refrigeration. “HMS Habbakuk” (Habbakuk is a book of old Testament containing the prophecies of Hebrew minor prophet), as it was named, was to sit in the middle of the Atlantic as a floating aerodrome, or icedrome, to handle the refueling of aircraft flying from the U.S. to support the anti-Nazi was. It was the idea of Geoffrey Pyke, a polymath who had been a journalist, spy, educator, and investor. During the war, Pyke was on the staff of a think-tank run by Lord Mountbatten. “HMS Habbakuk” was one of a number of wonderful ideas that Pyke was to continue to generate throughout the war. Mountbatten found many of them significant enough to push hard for their approval by the British War Office. Even so, the concept of an ice ship was extremely difficult to sell. Pyke had sent as memo explaining the concept to Mountbatten, written in rambling detail. This is not very surprising as the memo weighed over 2 kilograms and was several hundreds pages long. The memo began with the notion that it was possible to make a very heat-resistant ice by mixing it with wood pulp. The idea had occurred to Pyke, perhaps, through the example of the Inuit (Eskimos) who in those days till made their traditional homes by mixing ice with lichens to make it strong. Pyke suggested that it would be possible to freeze together in huge blocks a mixture of water and something cheap and plentiful like wood pulp, he calculated that the resulting solid would be as strong in stress resistance as steel. In fact, experiments with a 14 per cent wood-pulp mix showed that it was even better, and it was thought that this new substance, now named Pykrete, should be relatively easily fashioned into ship-building material. Pyke had a sample made, and delivered a large block to Mountbatten, who whisked off with it to Winston Churchill. There is a story that Churchill, smoking a large cigar, was in his bath when the ice arrived. Invited to the bathroom, Mountbatten sat on a chair near the edge of the bath and on an impulse, dropped the large slab of Pykrete in the hot bath water. It floated around between Churchill’s legs, impervious to the heat. The idea gathered momentum, and a group of engineers met in Canada to build some experimental models of the ship, and to best the practicality of working with ice as a material. They built a model 100 feet (30.48 metres) long, and it proved to be tremendously strong. Mountbatten demonstrated this convincingly by using a shotgun, showing how the ice was completely unharmed by bullets fired even at close range. By the early months of 1945, the ship looked likely to be made, but the project was written off when Allied victory was announced in Europe, and then, a little later, came the surrender of Japan. Pyke was offered the chance to patent (thank God there were no GATT rules then) his odd material, but he decided not to. The project, recorded in the huge memo, is now in the archives at Broadlands, the Mountbatten home. Pyke died from cancer in 1948. “MS Habbakuk” would have made an extraordinary machine, certainly the largest manufactured object on earth, both then and even into the present times. It would also have been very safe: it was believed that the ship, with its 30-foot walls, could easily absorbed by impact of a torpedo. And should a crack appear, why, turn up the on-board refrigeration, and mend the hole with sea-water ice! Research has been done into combinations of ice with other materials, most notably glass fibre, in the ice laboratory at the
Massachusetts Institute of Technology, but no suitable use for ice has turned up. It is unlikely that anyone, even the petroleum industry, with its eyes on Antarctic Oil, will use ice alloys to build tankers. No ship will ever sail with a hull made from ice — but we should think what a great loss to the romance of seafaring. |
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This Universe When we touch a liquid, it sticks to (or wets) the skin, but when we touch a solid, why does this not occur? Also, why is water transparent and ice whitish? I appreciate your curiosity. Let us look at your first question in a simple way. If some thing sticks to your fingers, it implies that its molecules are not so strongly held together to each other. Some of them can separate from their companions and go their own way. This they can do if there is something that attracts them. When you put your finger in water, some of it sticks to you because there is an attractive force between the material of your hand and the water molecules. Water does this with a wide variety of materials. If you look at the surface of water in a testtube, or for that matter in a glass, you would notice that near the walls of the glass water seems to rise a little; as if it wants to climb up. In fact if the tube is narrow enough, as for a capillary tube, water will rise quite high. That is how oil rises in the wick of a lamp, or sap to the top of a tree. If water did not wet your hands, we would not have had any plants and trees! This would be true if the trees decided that they prefer to be made of Teflon, the material with which some of the modern non-stick frying pans are coated. Perhaps it is good to remind you that all liquids do not behave the same way. For example, mercury does not wet your hand nor would it rise in a glass capillary tube. Everything depends on intermolecular forces. What is the difference between frozen snow and ice? Frozen snow is a large number of tiny ice crystals piled up together with a lot of air spaces in between. It looks so white precisely because of this structure, in which there are an infinite number of ice-air interfaces to scatter the incident light. Indeed, there is so much entrapped air that people buried under snow can actually survive for quite a while if they use some porous covering on their faces. Ice is highly compacted frozen water from which all air pockets have been removed. This happens under pressure. For example, the thick mass of ice, some kilometres deep, on Antarctica is quite transparent. The water constituting this ice must have precipitated as snow, some of it thousands or millions of years ago. There is also, of course, the ice we make in the freezer compartment of our refrigerator. That is also transparent. Clearly, the conditions in our freezer are not designed to make snow, though you must have noticed that freezing of moisture on the walls of old freezers results in the formation of a whitish cold mess that is not clear like the ice in the ice tray. It is more like hard snow than honest ice. What is the longest time spent by humans in space without contact with the earth? On which space station was this record established? I have forgotten the exact figure, but it is many, many months. The space station was definitely the Mir, belonging to old Soviet Union. The astronauts (or cosmonauts as they call them in Russia) were not without contact with the earth. Besides radio and television, they also had supply rockets coming from the earth, and colleagues visiting for shorter duration. This should not give an impression that living in microgravity conditions in a relatively cramped environment is much fun. The body is confused, metabolism has to readjust, bones tend to get weaker and the packing between the vertebrae of the spinal chord expands a little, resulting in an increase in height by a few centimetres.
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Trends Heart attack survivors whose hearts were infused with stem cells from their own bone marrow showed nearly twice the improvement in the organ’s pumping ability as patients given a placebo, according to a new study. A further analysis of the data found that benefits to heart function seen four months after an attack appeared to be most pronounced in patients with more severe heart attacks that caused greater damage to the muscle, researchers said
yesterday at the American Heart Association annual scientific meeting. — Reuters
Time Invention of the Year Snuppy, the first dog created by cloning, has been named as “2005 Invention of the Year” by Time magazine.
“Plenty of labs do mammalian cloning these days but the group that produced Snuppy is, like the puppy himself extraordinary,” the magazine said, pointing out with striking regularity Woo Suk Hwang and his 45-person team had cranked out one cloning breakthrough after another in their laboratory at Seoul National University in South
Korea. — PTI |
Historically, India has witnessed energy shortages. According to the Central Electricity Authority, in fiscal 2005, demand for electricity exceeded supply by an estimated 7.3 per cent (7.1 per cent in fiscal 2004) in terms of total requirements and 11.7 per cent (11.2 per cent in fiscal 2004) in terms of peak demand requirements. Although power generation capacity has increased substantially in recent years, it has not kept pace with the growth in demand or the growth of the economy generally. According to the United Nations, India, with 355 kwh per capita electricity consumption in 2000, has one of the lowest electricity consumption levels in the world, in part due to unreliable supply and inadequate distribution networks. This contrasts with 827 kwh per capita in China, 1,878 kwh per capita in Brazil and 12,331 kWh per capita in the United States, in 2000.