Chandigarh, Thursday, November 12, 1998
Hydrogen as a fuel
Features of a
WHEN an automobile travelling at nearly 60 km/hour hits a stationary object, it just takes one-fifth of a second for the collision to be over. This is often compared to the blink of an eye. The whole sequence of events in a head-on collision just takes about two blinks of the eye. The sequence of these events have been studied and recorded as follows:
Now think of this in the terms that if the automobile travelling at 60 km/hour collides head-on with another automobile coming in the opposite direction at 60 km/hour, instead of a stationary object, the time for such a collision will be about half of what was earlier measured. That is to say that such a crash will take place in a blink of the eye (one-tenth of a second).
One shudders at the thought of going through such a crash. Of course the speeds at which the automobiles run on the highways are much higher than the 60 km/hour used in the tests. Thus there is all the more reason to be aware of the accidents and the injuries and fatalities they cause.
Research is going on all over the world that can make highway drives safer. A number of safety features have been developed which can be fitted on to the cars such as the seat belts, air bags, collapsible steering, side impact beams, anti-lock brakes, and traction control. Studies are on to study the effectiveness of these features individually in injury avoidance. Together on the car these features complement each other in working for human safety.
Three Point Seat Belts
The seat belts are the single most important safety feature in a car as it ties the person down to that portion of the car which does not get much affected in case of a collision. There are tighteners provided with the belt. The function of the tightener is to remove the slackness between the body of the person and the belt so that there is no free movement of the body in case of collision. This tightening of the belt is triggered by sensors, which are so located in the car that within 0.01 second of the start of the collision, the belts start tightening.
An air bag acts as a pillow of air, which cushions the forward motion of the human body when it is thrown forward in case of a head-on collision. It prevents the body from striking against the dashboard, the windscreen, and the steering wheel that may be cause of injuries to the driver and the passengers and in many cases is fatal. The air bag is a folded piece of special fabric inside the glove compartment or the steering wheel. It gets inflated within 20 to 40 microseconds and cushions the unsafe forward movement of the occupants of the vehicle.
A lot of study is being carried out to develop new technologies for more effective air bag deployment. Some constraints in this research include the limitation of installation space and inflation time available. Presently there are two techniques being used for air bag inflation: in one case sodium azide pellets are ignited which releases huge quantity of nitrogen gas for inflation of the air bag. The second system is a hybrid technology that uses an inert gas (argon) under high pressure and heat from a propellant significantly increases the gas volume to inflate the air bag within the stipulated time span.
For the deployment of the air bags and the belt tighteners, crash sensors have an important function to perform. These sensors are placed strategically around the front-end crash zones of the car. A steel ball type sensor and its function in initiating the inflation of air bags is shown in the figure 1 (a,b,c).
Side impact beams
In case of side-on collisions, the seat belts and the air bags are not able to provide adequate protection. For this reason strong anti-intrusion beams are provided inside the doors.
The beams are structurally connected to certain other members of the car frame. The impact of the side-on collision is transferred to these associated portions of the passenger compartment such as the roof pillars, the floor structure, and the steel tubes within the seats. These then direct the forces to an energy absorbing section of the cars central tunnel area.
Chest injuries to the drivers have occurred due to piercing effect of solid steering column tube. An energy absorbing collapsible steering column provides safety by collapsing under a front end crash, thus absorbing the energy which would have otherwise have been transmitted to the driver and cause him injury. A telescopic collapsible steering column is shown in figure 3.
Locking of wheels while braking often results in loss of control over the automobile and also the automobile takes a longer time and distance to stop as compared to what it would have taken if the wheels were not locked. To avoid this locking of brakes when pressed hard, sensors are provided to the wheels of automobiles, which compares the relative motion of the wheels. In case of braking if a wheel gets locked, special equipment is provided to rectify this. Thus ABS acts as a safety feature, helping automobiles to stop faster and without loss of control.
Safety of the occupants of an automobile is an important criterion while designing of the automobiles. There are automobiles available in the market, which have these safety features. However the prices of these automobiles is a limiting factor for the common man to purchase. Research is going on to find cheaper and inexpensive alternative for these safety features. But till that time one has to do with what is available, after-all these safety features have to serve you once in an emergency situation to be worthwhile.
Hydrogen as a
THE fast depletion and eventual exhaustion of fossil fuels have made it imperative for scientists and technologists to search for alternative energy sources. In the wake of the depletion of fossil fuels, finding substitutes for the two primary sources the electricity and the fuel (oil) will form a major step in circumventing the energy crisis. The Energy is inextricably interlinked with the economic growth of any country and more so for a developing country like ours. The best hope for coming out of morass of poverty is to accelerate the pace of economic growth and for achieving this the availability of energy at an increasing cost is a must. The energy stock is getting less and less and the energy that we would need to accelerate the economic growth would be more.
One possible substitute whose feasibility and utility has been demonstrated world over is hydrogen which corresponds to a fuel gas which is an energy and also its carrier. Hydrogen is almost an exact substitute for oil and it effectively serves all the purposes being carried out at presently by oil. It has been demonstrated that hydrogen as fuel scores over conventional oil (petroleum) in all the respects the efficiency, the performance and the noise.
One of the most attractive features of hydrogen as a fuel is that its primary material source is water. Thus if it can be produced from water through solar energy it can be considered as a primary energy source even though it does not occur as such in nature. Another important characteristics of hydrogen as a fuel is that when it is burnt to get power and heat, the combustion product is mostly water itself. Therefore, as a fuel it is non-polluting and it reverts back on burning to the very source from it is produced.
Hydrogen represents manifold energy options. It can be used for indoor energy utilities e.g. as a cooking gas, for heating and cooling space, etc. It can also be converted to electrical energy through fuel cell. However, its most potential use in immediate future is as a clean and high efficiency fuel for use in boiler for steam generation and transportation particularly for road transportation (automobiles etc).
Since fuel corresponds to a major energy need, hydrogen is bound to enter in a big way as a possible energy option and a substitute for the oil/petroleum which is a polluting fuel and is getting depleted to eventually become non-existent.
1. Name the ancient Indian astronomer mathematician who is credited for giving the most accurate value of the constant pi as 3.1416. Name also the scholarly book on mathematics and astronomy which he wrote at the age of 23.
2. Indian aeronautical scientists and engineers are working on a project to produce aeroplanes that can fit into the palm of a human hand. What is the general name given to these tiny bird-like aircrafts which can fly into risky spots and gather required information?
3. HGVS is a voluntary organisation of Himachal Pradesh devoted to the cause of science and environment. What is its full name?
4. What is the number of king and queen honey-bees in a beehive? What are the rest of the bees called? What is their number?
5. A myopic eye cannot see distant objects whereas a hypermetropia eye cannot see near objects clearly. Former is corrected by concave lens and the latter by convex lens. An astigmatic eye cannot see wire gauze lines clearly. Which type of lens is used for its correction?
6. Name the two protected and endangered species of animals which were allegedly killed by two popular film actors near Jodhpur recently.
7. What is the process called in which a solid gets directly converted into gaseous form on heating, without passing through the liquid state? What is the chemical name of the substance which undergoes this process when used for tinning utensils?
8. Kidneys purify blood in human body. Which process is carried out to purify blood in case of kidney failure?
9. Name the instrument that is used in a submarine to see objects above the surface of water.
10.Who wrote The Book of Indian Birds and handbook of the Birds of India and Pakistan?
A new X-ray technology to produce sharp pictures of bones and soft tissues like muscle, nerve, blood vessels and cartilage has been developed by researchers at the Australian Council for Scientific and industrial Research Organisation (CSIRO).
The new technology provides sharp images of soft tissues, body organs and bones and needs only half the dose of radiation required for conventional radiography, says a report in Ascent Technology Magazine.
Apart from its medical uses, the X-ray machine can be used to inspect packaged goods, foodstuffs and baggages and for quality control of computer chips.
The device works on a principle called phase contrast imaging (PCI) which measures the bending or refraction of X-rays. This high-precision measuring is necessary as X-rays travel faster in denser tissues and in the process, get refracted by the lighter ones.
PCI can be incorporated in X-ray machines in the same way as the Dolby noise reduction technology is built into quality stereo sound systems.
New method of seed dressing
To meet the demands of intensive farming, German scientists have developed an eco-friendly route for seed-dressing by bombarding seeds with low energy electrons.
Researchers at the Fraunhofer Institute for Electron Beam and Plasma Technology in Dresden in collaboration with the German Federal Institute of Biology in Agriculture and Forestry have developed this purely physical process called e-dressing.
Since electrons pass through the seed shell and not through the seed leaving the germ untouched, the new method is in no way comparable with irradiation and is better than chemical treatment, reports Fraunhofer Gesellschaft Research News.
At present, more than 90 per cent of all seeds for cereals, maize, sugar beet and rape are chemically dressed to hinder the spread of plant diseases. Species of fungal diseases such as tilletia caries, fusarium mould, or septoria leaf and glume blotch can lead to drastic reduction in yields.
Fire extinguisher inside cable ducts
German scientists have come up with a new fire extinguishing technology that can stop fire inside cable ducts.
The new fire fighting tube (FFT) protection system, developed by a Siemens engineer Gerhard Draugdates, flights flames exactly at the source of fire, reports Siemens Telcom News.
A special tube is inserted along a strand of cable. Attached to the tube are fire extinguishers at intervals of 50 meters. If excessive heat develops in the cable duct, the sheath of tube melts creating a leak through which a fire extinguishing agent escapes.
At the same time, gauges report the sudden drop in pressure and trip an alarm which pinpoints the fire in addition to saving time.
Paint to outwit radio detection
A coat of paint on an object is all one needs to outwit radio detection, say Russian scientists who refute claims of Americans being the first to develop it.
The superpaint called tikolak can make an object invisible to radar detection by suppressing and preventing electromagnetic waves emanating from it, according to Ria Novosti.
The paint, which was approved by the Russian State Registrar of Invention last year, would not only revolutionise the defense sector but would also help reduce harmful effects of electromagnetic radiation emitted from a number of sources.
A coat of tikolak on military hardware would render it invisible from radar detection, making it invulnerable to attack.
It would also help lessen the deleterious effects of radiation emitted from industrial, medical and electrical equipments, the report says.
The paint, claimed to be cheaper than the American one, was developed using a combination of soot and graphite in a special suspension medium.
Paper from banana stalks
A new technology to transform stalks of banana plant into high-quality paper, rope, cardboard and twine has been developed by Australian researchers.
The technology, developed by researchers of Papyrus Australia Private Limited, is based on an ancient gyptian technique of making writing material from the stem of papyrus, an aquatic plant found in North Africa, reports Ascent Technology Magazine.
Traditional methods of making paper products involve a pulping process which destroys the natural length of the fibre, leaving behind a substance which has to be reprocessed.
But the method is expensive and time consuming due to the amount of water, additives and electricity involved, the report says.
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