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| SCIENCE & TECHNOLOGY |
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Tackling forest fires
THIS UNIVERSE |
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Tackling forest fires Forest fires have become a constant worry for forest management. The malignant impact of forest fires on environment and health of people is simply lacerating. Fires over sylvan lands occur naturally due to lightning but intentional and unintentional human interventions are equally responsible. Forest fires are basically of four types:
Ground forest fires occur because of burning of roots and other organic combustible stuff beneath the surface. It spreads gradually and flames rarely touch a height of two metres. Important factors determining the cause and spread of forest fires are: 1. High atmospheric temperatures. Electric sports, lightning, bonfires, cigarette cinders are the prime source of ignition. Once started, fire is sustained by the continuous supply of oxygen in the air. Approximately 90 per cent of forest fires are due to human negligence or carelessness. Lightning and meteorites are major natural causes of the remaining 10 per cent. During summers, the air temperatures are high. Dry leaves and other vegetation catch fire. Oxygen, fuel and heat are the three essential components. Dead plants, tree leaves, bush, grass comprise fuel and the heat is induced naturally or intentionally. The various factors determining the intensity, extent and magnitude of forest fires.
Dangers of Forest Fire a) Emission of harmful gases Forest fire management Forest Fire is a global nuisance. Indian efforts in this regard are less effective. Most of the endeavours are done with sudden energy and instantly. a) All possible prevention. Development of forest fire line is an age-old preventive measure and has always proved successful in controlling forest fires. Educating the people about do’s and dont’s to prevent forest fires is very important awareness programmes conducted a different levels among the people and directly associating them can bring good results. Manual surveillance during the hot and dry season is indispensable. Establishing search towers/watch beckons can also help in early detection of forest fires. Use of infrared imagery and smoke detectors are other detection options. A quick reconnaissance of fire site and timely relay of information to action team can prove decisive in controlling forest fires. Water, dust-stand and bush thrashing can control low intensity fires. The role of local population is highly conspicuous. An axiom survival of forest is essential for their own survival. Use of aeroplanes and helicopters has increased detection and suppression of forest fires. Chemicals and water are sprinkled over infernos. Making counter fires is an effective technique. Sometimes fighters themselves lead fires on to difference fronts and an attempt is made to intersect uncontrolled fire for an automatic suppression. The National Forest policy 1988 clearly lays emphasis on prohibiting the tribal people from dealing ecology clumsily.
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Making Tamiflu cheap From late 2005 the threat of a flu pandemic has massively increased demand for oseltamivir - better known by its trade name Tamiflu. Now manufacturer Roche has joined forces with other companies to boost production, and generic drug makers have started producing their own versions. So supplies of the drug look set to meet or even outstrip demand by 2007. But significant questions remain - such as the treatment’s affordability to poorer nations and its efficacy against the H5N1 bird flu virus. While generic versions currently cost as much as Tamiflu, competition will probably drive prices down. More promising news for developing countries, perhaps, is the work of researchers at Harvard University in the United States, who have devised a cheaper way to make the drug. — SciDev.Net N-science for development As tensions mount over Iran’s nuclear standoff, the risks of radiation-based technologies are surging back into the headlines and onto public agendas. At the centre of the fray, one UN agency carries the unenviable responsibility of regulating one of modern science’s most controversial advances. The UN’s International Atomic Energy Agency (IAEA) is best known as the world’s nuclear watchdog; an intergovernmental body that argues against the proliferation of nuclear weapons, and sets international standards for the safety and security of radiation sources. But its mandate also includes ensuring fair access to nuclear technologies. These already play significant roles throughout society, in areas as diverse as health, nutrition, agriculture and environmental management. The IAEA is firmly “pro” nuclear - with an emphasis on risk management. Over the past decade, its Department for Technical Cooperation (TC) has helped more than 90 developing nations set up the necessary support mechanisms for managing the risks of radiation-based technologies. — SciDev.Net Saturn spin is slow Saturn, a giant gas planet encircled with yellow and gold bands, is spinning slower than expected scientists said.
Instead of a day on Saturn lasting roughly 11 hours, an international team of researchers has calculated the rotation period is 10 hours and 47 minutes — eight minutes slower than estimates from the NASA voyager results from the early 1980s. “Making this measurement has been one of the team’s most important scientific goals, said Prof Michele Dougherty of Imperial College, London.
“After almost two years of collecting date we are starting to get fascinating insights into Saturn, but we still have more questions to ask,” she added in a statement.
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THIS UNIVERSE Kindly tell me how can molecules in a snowflake influence other molecules positioned thousands of molecules away to form the same macroscopic shape and create six-pointed (hexagonal) design? I am charmed by this question sent by a 9th class child. She could have gone on and asked how do the molecules of today send instructions to snowstorm a thousand years away that it must make snowflakes of only this shape and design – which they would be. One of the joys of being connected with this column is that such questions leak through the barriers of school syllabus and propriety of questions posed and discussed in class. I believe any kind of wondering about such questions is precious even if the answer seems obvious to those who have forgotten to dream and fantasise. The obvious answer to this question is that the molecules do not behave in a specific way because anybody tells them to do so. Under same conditions they just have to be themselves. As the temperature is lowered close to freezing level they slow down in their random motions and because of their shape and attendant forces snuggle in to the lowest energy level collective. Unless they are overruled through violent temperature and wind conditions the least energy condition gives them their shape. If there is no room near one crystal birthing they do not grumble but wander off to be accommodated elsewhere. There is specificity to the crystal structures that different molecular species can form. A lunar eclipse occurs when the Moon passes into the Earth’s shadow. Instead of being completely dark the Moon sometimes has a copper-red tinge. How does it happen? As you say, the lunar eclipse is caused by the Earth coming in between the Moon and the Sun. For a resident on the Moon it would be a solar eclipse caused by the Earth. But the earth also has an atmosphere. Even though it is a thin layer of sparse matter surrounding much larger solid earth, it has an interesting consequence. Even after the moon has moved into the Umbra region of the earth shadow - meaning the deep shadow completely covers the moon, some light can still reach it after being scattered through the thin layer of the atmosphere. This light would have passed tangentially through the earth atmosphere and would have been subjected to intense scattering. The blue, green and yellow components of light would have been scattered wide away from the moon, but for the longer wave-lengths of light lying in the orange and red region the chance of reaching the moon surface would be greater. That is the reason that colours similar to those we see at sunrise and sunset illuminate the dark part of the shadowed moon. Basic physics is the same. During some eclipses of the Moon the copper colour of the moon is deeper than in others. This difference might be due to presence of scattering centres in the upper atmosphere caused by volcanic activity, or thin high clouds. |
