SCIENCE & TECHNOLOGY
 



  Tackling road accidents
Radhakrishna Rao
O
VER the last two decades consequent to a rapid increase in the number of motor vehicles and a phenomenal expansion of the road network, there has been a steep rise in the incidence of road accidents in India.

Dirty bombs
Deepak Bagai
A
dirty bomb is an explosive device manufactured to spread harmful radioactive material over a wide range. It is different from the nuclear bomb, in the sense that its primary goal is destructive power, and not radiation damage.

Prof Yash Pal

Prof Yash Pal

UNDERSTANDING THE UNIVERSE
WITH PROF YASH PAL

Cassini spacecraft was launched in 1997 and made its way to Saturn in 2004 while flying twice past Venus, once past the earth and another time passing near Jupiter. Why this long dancing around was needed?
This represents very clever mission planning in which some of the momentum was stolen from each of the planets the spacecraft passed by. Without such a manoeuvre this spacecraft weighing 6,000 kg would have taken decades to reach its target!

New products & discoveries

  • “Plankton power”

  • New way of “seeing”

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Tackling road accidents
Radhakrishna Rao

OVER the last two decades consequent to a rapid increase in the number of motor vehicles and a phenomenal expansion of the road network, there has been a steep rise in the incidence of road accidents in India. Road accidents considered both a social problem and a medical challenge result in the death of about 85,000 people and injury to about half a million people a year on about two million km road network spread across the country.

Incidentally, India holds the dubious distinction of registering the highest number of road accidents in the world. According to the experts at the National Transportation Planning and Research Centre (NTPRC) the number of road accidents in India is three times higher than that prevailing in developed countries. The number of accidents for 1000 vehicles in India is as high as 35 while the figure ranges from 4 to 10 in developed countries.

As it is, the Indian roads which are far from ideal to ensure a smooth flow of both vehicular and pedestrian traffic reflect the “reality of the land”. In fact, road friendly policies and strict implementation of traffic rules and regulations could result in a drastic decline in the incidence of road accidents. According to Dr Dinesh Mohan, Honorary Ford Professor for Biomechanics and Transportation Safety at the Indian Institute of Technology (IIT) in New Delhi a recent study in Europe estimates that 46% to 51% reduction in fatalities result from the policies of compulsory seat belts, controlling drinking during driving and safer vehicle design. A substantial part of the reduction in fatalities is to be attributed to a set of measures aimed at improving the lot of pedestrians and cyclists through an improved road design and a better traffic management methodology.

On the other hand Geetam Tiwari of the New Delhi based Transportation Research and Injury Prevention Programme (TRIPP) is of view that streets must be retrieved to pedestrians not only because they are the majority road users but also for the efficiency of the overall road management system. Says he, “If pedestrian-friendly paths and separate, segregated lanes along with sufficient space for hawkers are created for slow non-motorised vehicles, the curbside lane, which is currently used by bicyclists and other non-motorised vehicles becomes available to the motorised traffic”.

Of course, a number of projects are on across the country to provide timely and effective relief to the victims of road accidents. For instance, in Bangalore the Manipal Hospital has joined hands with the hospitals on highways and launched a project named Operation Sanjivini aimed at providing emergency assistance to accident victims on the highways. As part of the Operation Sanjivini the hospitals on the highways in association with the local NGOs (Non Govt Organisations) will position well equipped ambulances at almost every 50-km stretch of the highways.

On the other hand Dr Subroto Das and his wife Sushmita have launched an ambitious Highway Research Project (HRP) as part of the Lifeline Foundation, a voluntary organisation. Significantly so far under HRP more than 400 persons with critical injuries and over 300 people with major injuries have been saved. Based in Vadodara, HRP reaches to the accident spot immediately on getting the message. It has launched 14 projects for highway accident victims in the states of Goa, Karnataka, West Bengal and Kerala. This is claimed of be one of he first of its kind in the whole of South Asia. “Most of the lives can be saved if medical attention is provided in the first crucial hour which is called golden hour”, says Dr Das.

In the major urban centres of India reckless driving by private bus drivers contribute in a big way to the road accidents and consequent injuries and fatalities. No wonder along with industrial fatalities, road accidents have become the third largest killer in the country after heart diseases and cancer. Accidents also cause an estimated loss of Rs 8000 million to the country’s economy.

Significantly, about three-fourth of the accidents occur on the roads of Indian cities which account for just 7 per cent of the total road network in the country. According to traffic police in New Delhi environmental factors, including heat and dust make their own contribution to the road accidents in the country. Says a traffic policeman, both men and machines are under stress. This is evident in the behaviour of motorists, cyclists and pedestrians, especially during hot months”.

Interestingly, field studies carried out in Finland and Denmark show that “people who are failures in their personal lives and those who have low levels of occupational satisfaction are the one who get enraged on the roads”.

Major accidents in big cities many a times involve pedestrians. For instance, in Bangalore, indisciplined pedestrians have been found to be responsible for many accidents. A study of the high accident frequency locations in New Delhi has revealed that at these locations about 80 per cent of the fatal and severe injury occurred due to driving faults.In the ultimate analysis, the congestion of population, the concentration of industrial and workspots, increasing vehicular density and erratic pedestrian behaviour conspire to make India a highly accident prone country.
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Dirty bombs
Deepak Bagai

A dirty bomb is an explosive device manufactured to spread harmful radioactive material over a wide range. It is different from the nuclear bomb, in the sense that its primary goal is destructive power, and not radiation damage.

A dirty bomb contains the mixture of the explosive TNT (trinitrotoluene) and the radioactive material. The basic goal of the dirty bomb is to spread radioactive material in the form of a dust cloud, over a large geographical area. The radioactive material generates ionising radiations, which include alpha particles, beta particles, X-rays and gamma rays. These radiations possess power to remove an orbital electron off an atom. This results in an imbalance between the positively charged protons and negatively charged electrons, thereby converting an atom into an ion. The free electrons collide with other atoms to produce more ions. These ions affect the human body leading to unhealthy chemical reactions inside cells. The charge can break the DNA chains and a cell with a broken DNA strand will die or develop mutation. This activity can result into various dreadful diseases like cancer.

In a dirty bomb, the ionising radiation is generated from radioactive isotopes, which are the atoms that decay over time. The radioactive decay releases energy in the form of ionising radiation. The design and manufacturing range of a dirty bomb is dependent on the type and quantity of radioactive material. The dynamite and TNT are reasonably accessible whereas the radioactive material is not easily available. Certain hospitals make use of radioactive material in the research areas of nuclear medicine.

The amount of damage caused by a dirty bomb is unpredictable. The immediate deaths would be due to explosion and not the radiation. The prolonged exposure can cause havoc.

Till date there is no precedence of dirty bomb attack. Researchers converge to an opinion that a dirty bomb has disruptive rather than destructive effect. The fear of anthrax still haunts the Americans. The prolonged exposure of human body to the X-ray machine can also cause cancer. A dirty bomb will definitely increase the radiation level exposure above normal levels. Instead of instant killing the result will be silent killing over the years.
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UNDERSTANDING THE UNIVERSE
WITH PROF YASH PAL

Cassini spacecraft was launched in 1997 and made its way to Saturn in 2004 while flying twice past Venus, once past the earth and another time passing near Jupiter. Why this long dancing around was needed?

This represents very clever mission planning in which some of the momentum was stolen from each of the planets the spacecraft passed by. Without such a manoeuvre this spacecraft weighing 6,000 kg would have taken decades to reach its target! For accomplishing this crafty task the spacecraft was launched not in the direction of Saturn away from the Sun but in an orbit that would bring it close to Venus, which lies in the direction of the Sun. As it came to overtake Venus it was pulled by the gravity of Venus. If Venus were stationary the energy gained by the spacecraft would have been lost as it went past that planet. But Venus is not stationary. It has its orbital velocity around the Sun. This velocity got added to the velocity of the spacecraft, as it swept past. The gain in velocity was 5.5km per second. It is true that the planet must have slowed down a bit but not enough for it to notice. Using this gravity assist trick Cassini was sent past Venus once again and then past the Earth almost two years after launch! Following this came another steal from Jupiter in December, 2000, and it was away towards Saturn. Total gain in velocity through all these thefts was 21.44 km per second! To accomplish this trick in mission planning and accomplishment requires real genius.

I am told that the idea of using this method of designing planetary missions was due to a graduate student — some years ago. I wish I were as clever as that student. Perhaps some of my young readers are.

How does the coolant work in the car radiators?

The car radiators get very hot when the car is burning a lot of petrol. In fact, only about a quarter of the energy produced through petrol consumption is used in driving the car. The rest goes into heat to be removed with the help of the radiator or goes out of the tail pipe. It is good to run the engine as hot as possible because that way a greater fraction of the energy becomes available. But it also requires that the heat transfer to the air blowing over the radiator should be more efficient. When we use plain water with the radiator cap lose the hottest temperature of the radiator is the boiling point of water, namely 100º C. With a tightly closed radiator cap, the pressure in the radiator increases a bit, as in a pressure cooker. This does make the radiator more efficient. This efficiency can be increased when a coolant is mixed with water, because the boiling point of the coolant is higher than that of water; the radiator temperature can be higher than 100 degrees C without boiling. The car engine runs cooler.

During very cold winters, ordinary water would freeze within the engine block and the radiator. This is dangerous when you start the car because the coolant cannot flow for a while. In addition there is a danger that freezing of water and the consequent expansion might even crack the radiator or the engine block. Therefore for winters also we need antifreeze, which is another name for the coolant. Coolants used should be soluble in water; their freezing point should be low and the boiling point high. They should not damage the engine and should not be too toxic. Two of the coolants extensively used are ethylene glycol and propylene glycol.
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New products & discoveries

“Plankton power”

During the past two years, scientists have successfully tapped the chemical reactions from decomposing organic matter on the ocean floor to create fuel cells that can provide low levels of electrical power for many months. Last week, Oregon State University researchers announced that they have taken that development one step farther by harnessing the same power-producing decomposition activity from plankton taken from the upper water column.

“We’ve only had the experiments running for about four weeks,” said Clare E. Reimers, a professor in the College of Oceanographic and Atmospheric Sciences at OSU, “but it is clear that we can use plankton as a fuel source and that the water column is rich in microorganisms adept at shuttling electrons to fuel cell electrodes. The seafloor fuel cells that we’ve developed in the past are stationary and designed to provide power for equipment that doesn’t move - like the hydrophones used by the U.S. Navy or by OSU researchers for listening for earthquakes.

“But by harnessing plankton power, we potentially could fuel autonomous, mobile instruments that would glide through the water scooping up plankton like a basking shark, and converting that to electricity,” she added. “Such instruments carry sensors and are used today to map the changing chemical and physical properties of the ocean.” — Oregon State University

New way of “seeing”

A prototype microscope that uses neutrons instead of light to “see” magnified images has been demonstrated at the National Institute of Standards and Technology (NIST). Neutron microscopes might eventually offer certain advantages over optical, X-ray and electron imaging techniques such as better contrast for biological samples.

Described in the July 19 issue of Applied Physics Letters, the imaging process involves hitting a sample with an intense neutron beam. The neutrons that pass through-whose pattern reflects the sample’s internal structure-are directed into a row of 100 dimpled aluminum plates. Each dimpled plate acts like a weak focusing lens for neutrons, diverting the neutrons’ path slightly at each interface. The image then is projected onto a detector.

Adelphi Technology Inc. of San Carlos, Calif., designed and demonstrated the microscope with the help of NIST scientists. In principle, neutrons could provide better image resolution than visible light because they have shorter wavelengths-as short as 1 nanometer (nm) compared to 400-700 nm. In this demonstration at NIST’s Center for Neutron Research, the microscope produced a resolution of only 0.5 millimeters and a magnification of about 10. — NIST

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