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Coal-fired power plants take hits And now mobile batching plants! In the heart of brain
Trends |
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Coal-fired power plants take hits Coal-fired
power plants are taking hits from all sides. The unkindest cut to future coal-fired power generation came recently when Samuel Bodman, Secretary, the US Department of Energy (DOE), declared that the Bush administration had decided to withdraw funding to FutureGen, the US government’s effort to develop a “clean coal” power plant. The plant would have turned coal into hydrogen-rich synthetic gas, generating electricity while pumping carbon dioxide underground for permanent storage (The Wall Street Journal, WSJ, February 2, 2008). The project had international participation. The DOE found that the cost of the project soared to $1.8 billion, nearly double the original estimates. Now activists appeared to have shifted their attention from nuclear power plants to coal-fired plants. Referring to the example of Richard D. Libert, a Republican, a cattle rancher and a retired army lieutenant colonel, the New York Times observed that “an increasingly vocal, potent and widespread anti-coal movement” is developing in the West. Besides filing law suits, the environmentalists assert that “these coal plants don’t make any sense, whether from an economic or environmental or property-rights standpoint”. On October 18, 2007, the Kansas Department of Health and Environment (KDHE), USA, rejected a permit to Sunflower Electric Power to construct a pair of 700-megawatt, coal-fired electric power plants in Holcomb, a town in the western part of the state; the department believes that the greenhouse gas emitted by it threatens public health and the environment. The decision marks a victory for environmental groups that are fighting proposals for new coal fired plants around the country. We do not know of the impact the decision will have on coal power plants. In the USA, all combustion facilities need permits. The KDHE’s decision is the first of its kind taken by a government agency citing carbon dioxide emissions as the reason to reject a permit. “It would be irresponsible to ignore emerging information about the contribution of carbon dioxide and other greenhouse gases to climate change and the potential harm to our environment and health, if we do nothing”, The Washington Post quoted Roderick L. Bremby, Secretary of the KDHE, as saying. The writing on the wall was clear. On April 2, 2007, the U.S. Supreme Court ruled that the Clean Air Act gives US Environmental Protection Agency (EPA), the authority to regulate emissions of carbon dioxide and other greenhouse gases. Court cases around the country had been held up to await the decision in this case. Among them is a challenge to the environmental agency’s refusal to regulate carbon dioxide emissions from power plants, now pending in the federal appeals court. Between 2000 and 2006, US utilities submitted over 150 coal plant proposals. By 2007, they constructed 10 of them; 25 additional plants were under construction. But during 2007, 59 proposed plants were cancelled, abandoned, or put on hold. Concerns about global warming played a major role in 15 of these cases. Coal plants are being eliminated from long-range plans. The renewables are elbowing them out. Of the 59 plants which took the hits, 44 were abandoned by the utilities themselves because of increase in construction costs, insufficient financing or failure to receive expected government grants, lowering of estimates of power demand and concerns about future carbon regulations. Citigroup Inc, J.P.Morgan Chase & Co. and Morgan Stanley, three of Wall Street’s biggest investment banks announced the formation of The Carbon Principles, climate change guidelines for advisors and lenders to power companies in the United States. The new environmental standards will make it harder for companies to get financing to build coal power plants in the U.S. The banks will factor in the cost of emission capping regulations while lending money. Twenty something in the Wall Street rather than ‘environmentalists’ decided the fate of nuclear power in the 70s and 80s! With the development of clean coal technology stalled, nuclear power appears to have a brighter future; not quite, nuclear power is equally costly. Future energy options remain
unpredictable.
K.S. Parthasarathy is former Secretary, Atomic Energy Regulatory Board
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And now mobile batching plants! Installation
of a concrete batching plant at site has become a basic need for all infrastructure projects. Be it a nuclear, thermal or hydel project or a few kilometres long bridge or setu, be it a tunnel, a housing colony or any other structure, availability of a batching plant is essential if timely production of concrete coupled with full quality control over it is to be ensured. This realisation has already come home to the project developers and engineers. Today, batching plants with 30, 45, 60, 90, 120, 250 and even 330 cubic metres per hour capacity are being assembled in India by using fully imported mixing units. All these plants need certain foundations for their installation. The only problem that the builders face and dislike is shifting of the plant from one location to other on completion of a project, abandoning laid foundations at a previous location and laying new foundations at new location. Mobile batching plants: The problem has been solved now with the arrival of Mobile Batching Plants! These plants are self sufficient in themselves and include silos for storage of cement and aggregates. No foundations are required for their erection. Whenever a project is completed or its concrete requirements are fulfilled, the mobile batching plant can be moved to the next project without any fuss. Storage section: Mobile batching plants have compartment batchers that can be set up directly on the ground and need no foundations. Compartment batchers may have net storage capacity up to 70 cubic metres. The cement storage silos of about 3.0 metres diameter and capacity of 60 to 100 cubic metres are also on mobile foundations. With these storage capacities, concrete production up to 90 cubic metres per hour can be achieved. Batching equipment: Batching equipment adds all ingredients to concrete by weight. Volumetric equivalents are not used as some error may crop up in that. Batching by weight is best and most accurate. Therefore, load cells are used and weigh batching of cement, aggregates and admixtures is done. Even water is added by weight by use of pulse meter or water gauge. Cement hopper is self cleansing type and is connected to the mixing unit through a hose to avoid any pollution. Normally, mobile batching plants allow use of maximum 4 types of aggregates. 40 down aggregate is allowed if percentage retention on 40 mm sieve is discarded. Mixing equipment: The mixers used for mixing of concrete ingredients play a pivotal role in deciding the quality of concrete produced. For small capacity mobile batching plants, trough type mixers are used while for large capacity plants, twin shaft mixers are used. Twin shaft mixers ensure better mixing of concrete and save time. Concrete mixing time in twin shaft mixers is just 25 to 30 seconds per batch instead of normal mixing time of 2 minutes. |
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In the heart of brain Seema Gupta, a psychologist, has recently presented a paper on the working of brain and its implications on power transfer in an electrical engineering conference in Bathinda. She has propounded the conception that our body, if studied as a unit, could help in improving the efficiency of electrical transmission. For many years consciousness was shunned by researches studying the brain and mind. Consciousness is the awareness human beings have of themselves and their environment. However, it is a big question whether consciousness is a scientific question or a philosophical one. The microscopic view of our brain tells us that they are over 100 billion nerve cells known as neurons. Neurons are the basic structural and functional units of the nervous system. They carry information electrically. As electrons carry current, neurons carry information. Neuron has a nucleus which has genes and is surrounded by a cell membrane. They have two kinds of extensions -dendrites and axon. Dendrites receive messages from other neurons, whereas the information is transmitted through axons. Now here is the comparison. Axons have been taken equivalent of wires in this theoretical paper by Seema Gupta. Longer axons are usually covered with a myelin sheath, a series of fatty cells which is wrapped around them just what is insulation around a live wire. The end of axon is known by variety of names such as bouton, the synaptic knob or the axon foot. V.S. Ramachandran, Director, Centre for Brain and Cognition at the University of California, remarked in the Reith lecture, 2003, that each neuron makes something like a thousand to ten thousand contacts with other neurons and through synapses, where exchange of information occurs. |
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Trends Scientists involved in the joint U.S.-European mission are hoping observations and samples collected by the Cassini spacecraft will enable them to better understand one of the most dramatic geological features of the entire solar system.
— Reuters
But its size — 10 pounds and 16 inches long — isn’t the only curiosity. Researchers discovered the creature’s bones in Madagascar. Yet it seems to be a close relative of normal-sized frogs who today live half a world away in South America, challenging assumptions about ancient geography. The discovery, led by paleontologist David Krause at New York’s Stony Brook University, was published Monday by the journal Proceedings of the National Academy of Sciences.
— AP
Self-healing rubber band Anyone
who has heard the snap of a rubber band breaking knows it’s time to reach for a replacement. But a group of French scientists have made a self-healing rubber band material that can reclaim its stretchy usefulness by simply pressing the broken edges back together for a few minutes. The material, described on Wednesday in the journal Nature, can be broken and repaired over and over again. It is made from simple ingredients — fatty acids like those found in vegetable oils, and urea, a waste compound in urine that can be made synthetically.
— Reuters
Ancient brain surgery Greek
archaeologists said Tuesday they have unearthed evidence of what they believe was brain surgery performed nearly 1,800 years ago on a young woman - who died during or shortly after the operation. Although references to such delicate operations abound in ancient writings, discoveries of surgically perforated skulls are uncommon in Greece. Site excavator Ioannis Graikos said the woman’s skeleton was found during a rescue dig last year in Veria, a town some 75 km west of Thessaloniki.
— AP
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Electric
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spacecraft whizzed past Saturn’s moon Enceladus on Wednesday and through a huge geyser spurting from its south pole, collected samples of ice and gas shooting about 500 miles into space.
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frog the size of a bowling ball, with heavy armour and teeth, lived among dinosaurs millions of years ago — intimidating enough that scientists who unearthed its fossils dubbed the beast Beelzebufo, or Devil Toad.