 |
|
| SCIENCE TRIBUNE | Thursday, July 13, 2000, Chandigarh, India |
|
Cybersurfing with Amar Chandel Science Quiz
Toothpaste that
kills microbes
|
|
|
Are we prepared for floods? FROM time
immemorial, flood control structures have been constructed for protection of alluvial plains, low lands and human civilisation. In spite of the technological advances in meteorology and engineering for planning and execution of flood control measures, floods still continue to cause havoc in many parts of the world. Flood is a natural phenomenon and total flood control is not practical. There is a possibility of a high flood exceeding the one for which control facility has been provided. All that can be done is to adopt measures to minimise the damage caused by the flood. Floods occur frequently, in almost all the river basins, low-lying areas and costal areas of the world. Flood management is a time and area specific job. Detailed knowledge of impacts of flood is necessary for efficient planning and operation of flood management programme. It has been observed that flash floods just before and after the rainy season cause more havoc than that during normal rains. It has been experienced in 1988 and 1993. Often unseasonal torrential rains also cause floods. Notwithstanding the experiences gained over many years by studying the nature of flood and tremendous effort put forth for flood control, the damages caused due to floods have been steeply increasing due to the increase in the flood plain occupancy for developmental activities, encroachments due to increase of population, deforestation and other environmental degradation. For flood protection, all the rivers are provided with embankments and river training works. In Punjab there exist about 1550 km length of embankments on either sides of rivers and rivulets, about 2000 flood protection works and about 30 km pitching with apron. Such structural measures accomplish only flood moderation. These costly flood defence works need proper maintenance to have desired results. A factor of safety is required to be established with respect to discharge in the rivers as per the flood return period according to the National Flood Commission. The non-structural method includes flood plain management, flood forecasting and warning and flood damage prevention. Flood plain management includes the legal and administrative control over area prone to flood hazard through flood plain zoning, land use planning, restriction on certain activities in flood prone areas. Flood forecasting and warning systems have already been developed and may be further developed with information technology. So far wireless, fax, telephone, Mobilephones are used for dissemination of flood information. The creation of Websites is called for. Participation of people living in flood prone areas should be encouraged/mobilised. The following is the checklist for advance flood preparedness 1. Inspect all flood protection works such as embankments, river training works, drainage network and early warning systems to ensure their proper functioning. 2. Get cleared water ways under bridges, crossdrainage works etc for passing design discharge through them. 3. Get all the flood drains desilted as per priority according to past
experience and roster. 4. Ensure proper formation of groups for patrolling river embankments and vulnerable sites/works round the clock. 5. Ensure proper training of officials/officers who will be involved with flood fighting work. 6. See that public is educated through TV and mock exercises about flood hazards. 7. Ensure that key personnel, for flood management have adequate knowledge of emergency relief manual. It may be updated with experience gained and with the assistance of information technology for flood fighting. The operation of the flood management works is vested in the District Magistrate/District Collector, who is responsible for establishing coordination among different departments at district level to fight against anticipated disaster in advance. The coordination among different departments of the government is the prime factor for success of the flood management programme. The integrated crisis management before, during and after floods is an operation which is an acid test of coordination. The NGO’s/public may be encouraged to participate and coordinate. Similar management bodies are formed at subdivisonal level as well as block level. The apex body is at the state level. Action plan An action plan is prepared considering when the storm is coming, time available, area to be affected most, population to be handled etc. It is followed by disaster management in three stages: (1) Precautionary
stage (first flood warning stage), (ii) Action stage (second flood warning stage), (iii) Evacuation stage. These steps are for relief, rehabilitation and health care for flood affected people. In Punjab since 1990, Deputy Commissioners of districts have been made in-charge of flood control works in their respective districts. The purpose of transfer of works has been to have human approach besides technical support. Mostly, the works are executed as per recommendations of the D.C. at the instance of local MLA, Sarpanch and villagers. The engineers frame the justification/estimates accordingly. In such cases where the history of river flow, tendency to scouring, likely mood of the river during incoming rains, duration of flood peaks based on return period analysis are not defined, the provision of flood protection works is questionable. The office of the Chief Engineer (Drainage) is equipped with infrastructure to study and examine all sites and specially vulnerable sites as such a rational approach for design/provision of flood protection works may be evolved. The use of computers for flood works needs to be initiated. The data from the field regarding past floods, including the change in the river course due to siltation and erosion and change of the geomorphology of the area, may be processed along with rainfall data. The various degree of discharges may be impinged on the works of vulnerable sites through computer aided simulations to arrive at reasonable level of safety for the protection works. So for even model studies have not been initiated for the vulnerable sites where series of flood protection works are executed and replenished yearly. It is desirable that each site of work is monitored and cost of restoration evaluated to study the problem of scouring/damage to works in depth. In cases where embankments (Dhussi Bundhs) along rivers have been constructed long back, there is need to establish their design parameters. The degree of compaction and hydraulic gradient lines need be evaluated through test pits or opening outer profiles of the embankments near vulnerable sites. The discrepancy if any has to be set right before rains. The overall quality and health of embankments are required to be established. There is need to ensure that in case of predominately agriculture areas, a flood of 25 years frequency and for works pertaining to town protection and protection of important industrial and vital installations a flood of 100 years frequency may be adopted to fix design HFL. It should be checked to ensure a minimum 1.0m free board over HFL corresponding to 100 years frequency flood, where the bank is designed for 25 years frequency flood. It may be ensured that the top of bank is not lower than observed maximum flood level in the river. The writer is consultant for the Andhra Pradesh “Hazard Mitigation and Emergency Cyclone Recovery Project” aided by the World Bank. |
|
Cybersurfing
with Amar Chandel There are search engines galore but Yahoo continues to maintain its frontrunner position. The information that it stores is awesome and the speed is also quite adequate despite the fact that a phenomenal number of people log onto it. To cap it all, it continues to evolve and innovate. One of the latest editions is Yahoo India, the country-specific section. But frankly, this endeavour is a disappointment and seems to have been launched in a hurry. If you are looking for global information, things are rosy but India-specific information is sketchy. For instance, while searching under the head "Travel", try going to the "hill stations" segment and you will find only five places: Kalimpong, Kodaikanal, Lonavala (misspelt as Lanovala), Matheran and Yercaud. One hopes that such shortcomings will be removed quickly enough. Incidentally, Yahoo now uses the Google search engine. The results can be even faster if one goes straightaway to www.google.com and fills in one's query. The answers are available in a matter of seconds, but these are not very precise. For instance, I tried seeking information about "tourist spots of Rome". Besides many sites about the Italian capital, I was also referred to the beaches of Goa!
* * * * An enterprising Haryanavi computer expert, Sawan Deswal, is in the process of launching a website about his beloved State. He has compiled minute details about the humour, culture, history, archaeology, monuments and mythology of Haryana and put it up at the under-construction site http://hariyana.webjump.com. The profusely illustrated pages have a lot of information presented in an informal, readable style. Most of the research work seems to have been done by Mr Rajbir Deswal, a senior police official who has been writing on the culture and history of Haryana regularly. He happens to be Sawan Deswal's father. With a little more work on the presentation, it may prove to be a worthwhile website.
* * * * One of the biggest miracles of the world is a childbirth. The most common event has such complexities involved that even the knowledgeable people might get flummoxed. These have been presented in a simple, lucid form at www.first9months.com. The site gives you a virtual day-by-day account of those magical days. It is interactive; you can click on a particular day of a particular month to know of the status of the life growing in the womb. This information is matched with breathtaking visuals. |
|
Science Quiz 2. The Galileo spacecraft has recently taken pictures of an object in our solar system which show that it is constantly erupting molten rock, super-heated geysers and clouds of poisonous gases. Which is this most volcanically active object in the solar system? 3. MAO is an enzyme found in animals and its function is to break down certain biologically active amines in the body. What is the full form of MAO, which has adrenaline oxidase and tryaminase as its other names? 4. It has been recently found that the solution of a gas in water is very effective in killing micro-organisms like hepatitus A virus, E. coli bacteria and MS2 Virus. These are usually present on the surface of fruits and vegetables and can cause food-borne diseases. Can you name the gas the solution of which can kill these micro-organisms in about 5 minutes? 5. Acupressure is a technique which involves the application of pressure of nerve endings in our body, especially those near our hands and feet. It is said to improve blood circulation, induce relaxation and reduce pains and stresses. What is another name for this technique? 6. This Latin American plant was brought to India by the
British for ornamental purposes but it turned into a widespread weed eating up large vegetation and wetlands like lakes. Name this environmentally hazardous plant which, when dried, can be used to make paper and cardboard. Which Latin American insect can naturally eat and check the growth of this weed? 7. Name the branch of optics which deals with the production of lines of various colours present in a source of light and the measurement of the intensity and wavelength of these lines. Which instrument is used to make these measurements? 8. Name the component in the engine of a vehicle which consists of two electrodes separated by an air gap, on passing current through which the compressed mixture of fuel and air gets ignited. 9. Suggest another name for “the little neutral one”, well known in particle physics. Name its three species. 10. Name the first US rocket launched recently which was powered by a Russian engine and carried a European communication satellite, heralding a new era in international cooperation in the field.
Answers 1. Antonio de Egas Moniz 2. Moon 10 of the planet Jupiter 3. Monoamine oxidase 4. Chlorine 5. Reflexology 6. Water hyacinth; weevils 7. Spectroscopy; spectrometer 8. Spark plug 9. Neutrino; electron, muon and tau neutrino 10. Atlas III. |
|
Toothpaste that kills microbes A
US-based company has come out with a new toothpaste with chlorine dioxide as the active ingredient that kills microbes faster and more efficiently. Chlorine dioxide is a known odour neutraliser and an anti-microbial agent. As it converts into chloride after a short duration, there are fewer chances of presence of toxic compounds. Developed by Frontier Pharmaceutical Inc, the non-toxic and non-irritating toothpaste called “Dioxibrite (tm)” kills high concentration of microorganisms in less than a minute which significantly reduces the risk of gum diseases, oral infections and loss of teeth. Researchers of Westbury Diagnostic Inc, while testing the toothpaste, grew microbes on culture media and prepared suspensions. The suspensions were then mixed with the new toothpaste, incubated for a minute and then a chemical was added to inactivate chlorine dioxide, according to a release from the American Microbiological Society in whose 100th general meeting last month the results of the study were presented. Sound, Radars to
By simultaneously using sound waves to create tiny soil disturbances and precision radar to measure the resulting movement, US researchers have come up with a new method for detecting landmines. The new technique can be combined with other advanced location methods to create a new generation of equipment that can detect a vast range of buried weapons across various soil and environmental conditions. Details of the method were presented by researchers of Georgia Institute of Technology recently, at a meeting of Acoustical Society of America in Atlanta. Current mine detectors do not work in all conditions and have particular difficulty in finding small anti-personnel mines made mostly of plastic. The new technique uses a transducer to create seismic waves that travel through the soil containing landmines. This special class of elastic waves causes the soil and everything buried in it to be displaced slightly.
Polymer-based
mirror
A new type of reflective film made from polyester and other polymers reflects light with a brightness and versatility superior to other mirrors, according to a team of U.S. researchers. These thin, flexible polymer mirrors could be a boon to fields such as optoelectronics, lasers, electronic displays, optical fibers, and other lightrelated technologies benefiting communications, medicine and astronomy. Unlike other mirrors, these films can reflect visible light from all angles with great efficiency, researchers from 3M, a U.S. company, reported in the journal Science.
Bone from skin,
gum tissues
Using engineered skin and gum cells, US researchers have produced bones with the same hard outer coating, spongy interior and marrow core that is present in natural bones that may give rise to simpler and less painful bone grafts in humans. The bones, developed by researchers of University of Michigan, resemble natural bone and have been used to replace missing bones in rats. Apart from delivering the bone-forming proteins they were designed to secrete, the engineered cells participate directly in bone formation, a report in the journal Human Gene Therapy says. Current bone grafting methods involve harvesting a patient’s bone marrow with a long needle or surgically removing a piece of bone, generally from the hip. With the new method which is still in the developmental stages, a tiny bit of skin or gum tissue is removed, cut into even smaller pieces, and placed in a culture dish. Cells to repair
Scientists have come up with a technique to send trained cells into injured spinal cord to repair damaged nerve cells and restore normal functioning the way linesmen repair electrical insulation after a storm. In the new method, developed by researchers at Washington University School of Medicine in St Louis, USA, embryonic stem cells (formative cells) are turned into nerve cells called oligodendrocytes and injected into spinal cord. When the nerve cells were injected into the spinal cord of injured or mutant rats, they reinsulated naked nerve axons long arms of nerve cells that carry messages up and down the spinal cord. “This is the first demonstration that oligodendrocytes derived from embryonic stem cells can remyelinate in the injured adult nervous system,” says John McDonald, one of the researchers. Conditions that result in myelin loss, such as spinal cord injury, stroke, multiple sclerosis and transverse myelinitis, occur mainly in adults. |
 |
|
