The menace of noise pollution
by Krishan Kumar
IN the history of our planet, the last two centuries have witnessed a very rapid industrial growth. Various nations and states of the world have been competing with each other to achieve maximum possible levels of industrial production in order to attain quick economic prosperity.

New Products & Discoveries

Making the most of Internet
by H.S. Jatana

Even as business on Internet is being experimented with much vigor across the globe, most Indian companies are yet to comprehend and appreciate the benefits and advantages that the Net offers, let alone having their own website. The Internet is till something of a mystery to them; something they cannot fathom.

The few companies that did get on to the Net with their own websites have reported mixed results: many of them who rushed to the Net hoping that it would provide a solution to their sluggish domestic market sales were disappointed — the hordes of international buyers that they had expected did not turn up.

Yet on the other hand, many companies have positive remarks to make on their Net experiences. In a typical Indian company with an Internet connection, the Net is used mainly for sending and receiving e-mail. Incoming messages are printed by the secretary and dutifully placed on the manager’s desk. They are answered conventionally- the manager dictates a reply and the secretary e-mails it.

In most cases the decision-makers are completely ignorant of the technology. The Net is one step removed from the decision makers - they do not have PCs on their table and do not surf the Internet for information gathering. Because of this, decision makers do not understand the immense benefits they can derive from the Internet.

There are also instances of Internet telephony for branch office-head office communication. Some people who use it are not only satisfied with the clarity of the line and the speed of call connection, ultimately paying around the same amount as an STD call.

A friend to mine who is in the export business had all his brochures put on his site on the Net. Earlier, he used to carry these brochures with him, which meant heavy baggage. Now, he just logs on to his site when he is abroad and prints them out in colour and has his brochures ready! It is clear that the Internet is a goldmine of resources just waiting to be explored.

The Internet offers by far the most cost-effective way of publicising products and services to millions of potential buyers worldwide. From a return-on-investment angle, Internet is unbeatable-the investment is as low as Rs 15000 for virtual domain and the returns are far fatter.

The Internet offers a level playing field. Companies, both big and small, can compete as equals. Often the websites of smaller companies are more attractive and persuasive than the websites of larger organisations. And, as they say in the advertising world, the perception is the reality-small companies can exploit this to their advantage.

Most Indian companies feel that the Internet has international flavour. But a look at their e-mail messaging pattern will show them that a substantial portion of their e-mail is addressed to people or organisations within India. Companies can think of very effective ways of handling, for instance, customer support through the Internet. They could put up a Frequently Asked Questions (FAQ) section on their site that their clients can refer to when things go wrong or when the end user wants more information about how to correctly use a product or a service. This would substantially reduce the load on their support staff and also means after-sales-service costs lower than what is currently being accounted for.

When prices change (and in India they frequently do!) it would be very easy to put up the revised price list on the Internet and refer their clients to the site for the latest price information. This could be done within five minutes of the prices having changed.

The Internet offers companies with their own websites, a strategic business advantage. Most do not realise that slowly the rug is being pulled from under their feet. For example, a buyer in Sydney, Australia, urgently needs to import a certain product X. He turns to the Net, because it is the fastest information gathering mechanism available in the world today. He uses his favourite search engine to browse sites of companies offering the product X that he wants to buy.

And what does he see? Sites of Korean, Taiwanese, Chinese, Malayasian companies. He hardly sees any Indian sites. Who gets the order? A competitor abroad.

The Internet offers unparalleled communication speed at practically zero cost. An average e-mail message, sent to any part of the world, will reach within 15 seconds. That e-mail message could carry a CAD drawing or a photograph or a document as an attachment which can be viewed at the other end almost instantly.

India’s geographical position gives it an edge over others. It is almost exactly 12 hours behind the USA. This means that when the US sleeps, India is awake. Software companies have used this to there advantage. Why can’t other companies do the same? From a business perspective, messages from the US would arrive here, and be worked on/ answered overnight. The US buyer arrives at his office the next morning to find a reply/solution awaiting for him. He is impressed. However, companies in Europe or the far East do not enjoy the same advantage. Indian companies can capitalise on this.

The Internet holds large amounts of useful software. Recently I received two diskettes from two different companies, both had viruses. But the computer instantly detected the viruses and cleaned them. Thanks to anti-virus shareware that I had downloaded from the Internet.

If I want to use a dictionary, I can do it on the Net. If I want to find out the world time at different locations, I can do this on the Internet. In USA, one can even order a pizza or a hamburger on the Net.

So why are we not using all this technology?

The answer, sadly lies in the fact that we are still a step away from the Net. That our secretaries check out mail for us and print it out for us and that we reply the same way that our predecessors did. Most Indian companies have not used the capabilities of the Internet to even 0.01 per cent.

(The author is Member (VLSI) with Semiconductor Complex Chandigarh.)

The menace of noise pollution
by Krishan Kumar

IN the history of our planet, the last two centuries have witnessed a very rapid industrial growth. Various nations and states of the world have been competing with each other to achieve maximum possible levels of industrial production in order to attain quick economic prosperity. The wastes released into the environment as a byproduct of this industrial activity are much beyond the natural assimilated capacity of the environment. This , as a result,has put considerable pressure on various environmental systems and subsystems. In the last few decades, the concern about environment has grown appreciably. Environmental pollution has come to be recognised as one of the major threats to the existence of humans and various other species of the planet.

One of the important forms of pollution that affects the physiological and psychological well being of a person is noise pollution. Simply speaking, noise means any sound which annoys a person and affects his health adversely. Sound, basically, is a pressure perturbation or wave which travels in a medium (usually air). Human responses to a sound may be different for different persons. This means that same sound may be perceived as pleasing by one person and irritating by another one. Also, a person may respond to same sound differently at different times. For instance, the sound of music, that is annoying for a student while preparing for examinations, may be quite entertaining for him while dancing in a disco. Thus, the identification of a sound as noise becomes a subjective problem, even though there are some sounds that may be universally regarded as noise. However, the acoustical scientists have found that the degree of annoyance and other harmful impacts of noise experienced by a person are generally more when he is exposed to sound pressures of higher magnitude.

One often comes across the term decibel in the context of noise. What is decibel? Well, the range of sound pressures commonly encountered by human ear is very wide. Therefore, it has been condensed into a more manageable scale by devising the concept of sound pressure level (SPL). SPL is obtained by mathematically condensing the ratio of the observed sound pressure to a reference sound pressure. The reference sound pressure represents the average threshold of hearing for the normal healthy human ear and corresponds to a pressure of 2x 10-5 Pa. Though, SPL is a ratio, it is ascribed the unit of decibel (i.e dB) for the sake of convenience.

According to the definition of SPL, the reference sound pressure corresponds to a sound of 0 dB which, in other words, means a sound that is just audible to an average normal healthy human ear. The human ear is capable of responding to sounds upto 140 dB which represents the threshold of pain in the human ear.

In the context of frequency, the human ear is sensitive to sound waves in the frequency range of 20 Hz to 20,000 Hz. However, the sensitivity of human ear is not the same at all frequencies in this audible range. Human ear is more sensitive to sounds of middle frequencies (about 1000Hz) in comparison to the sounds of low and high frequencies. For this reason , certain weighting networks, which mimic the behaviour of human ear at different frequencies, are provided in the sound level meters which are used for noise pollution monitoring. For sounds commonly encountered by us, the A-weighting network is the most appropriate. Most noise standards are, therefore, given in dBA rather than dB. The ‘A’ used with the dB signifies the A-weighting network used for noise measurements.

Noise pollution affects the human health in several ways. Repeated exposure to noise may shift the hearing threshold of a person by several dBs either temporarily or permanently depending upon the level and duration of exposure. In extreme cases exposure to noise may lead to total deafness. Noise is also known to affect the health of a person by affecting him psychologically. It interferes with speech communication, disturbs sleep and affects work performance and thus causes anxiety in a person. An outcome of anxiety is the secretion of more gastric acids which then corrode the mucous lining of stomach. Medical studies have shown a higher incidence of peptic ulcer among the people exposed to higher levels of noise. Studies have also reported a rise in the blood pressure level of persons exposed to noise. Cases have also been reported where the bursting of crackers are found to be the immediate cause for the initiation of massive heart attacks.

Controlling the menace of noise pollution is, therefore, very important from the point of view of human health. The most suitable strategy to achieve effective noise control is to break down the noise pollution problem at hand into three parts, i.e. source, path and the receiver. We know that sound arises from a source or sources, travels through a path or paths, and affects a receiver or receivers. One can achieve reduction in the noise sensed by a receiver by any of the following ways:

• reducing the source noise through redesign or replacement
• modifying the propagation path of sound with the help of enclosures or barriers
• protecting or isolating the receiver
• using some combination of the above methods.

In general, source noise reduction is the most desirable since it avoids the cumbersome path modifications and uncomfortable personal protection (i.e. hearing protection devices). Source noise reduction is, therefore, given the top priority in all noise control methods.

(The writer is from the department of Environmental Sciences, Guru Jambheshwar University, Hisar.)

Science Quiz by J. P. Garg

1. A US satellite meant for espionage over a number of countries, including India, blew up in space recently. Name the largest unmanned US spacecraft that carried this satellite.

2. “The invention of aircraft will make war impossible in future.” Who made this announcement, which proved to be totally untrue in view of later world events?

3. What is the common name of deuterium oxide and where is it mainly used?

4. Ozone layer in the atmosphere, without which human beings would suffer serious biological effects from solar radiation, is being continuously depleted by man-made chemicals called CFCs. What is ozone actually? What is the full form of CFCs?

5. Polygamy is common in birds but one species of birds is strictly monogamous. Name this bird. In which country is it found?

6. This water animal, called “shushuk” in Bengali and “sihu” in Assamese, has disappeared from many parts of its habitat in India and is fighting a losing battle for its survival. Which is this animal?

7. These thin cables made of pure glass are extensively used in telecommunication these days. These cables hardly absorb any light falling on them and bounce it back and forth over long distances and around bends. What are we talking about?

8. What is the study of internal rhythmic patterns of human body called?

9. What is one word for ‘thousand billion’ in the American system of measurement? What is the name of this number in the British system?

10. HSTP run by a voluntary organisation “Eklavya” in Madhya Pradesh is a milestone and an innovative project in science education. What does HSTP stand for?

Answers
1. Titan 4 rocket 2. American brothers Wilbur Wright and Orville Wright (inventors of aeroplane) in 1903 3. Heavy water, used in nuclear reactors as moderator and coolant 4. A form of oxygen (o3); chlorofluorocarbons 5. Emu, found in Australia 6. River dolphin 7. Optical fibres 8. Chronobiology 9. Trillion; billion 10. Hoshingabad Science Teaching Programme.

Screens that bend
Call it electronic plastic. A material that illuminates when subjected to a low voltage offers great promise for a new breed of thin, flexible video displays. It was developed jointly by Japan’s Seiko-Epson and the British research firm Cambridge Display Technologies, who recently unveiled a 2-inch-square monochrome prototype a mere 2 millimeters thick. The partners hope to build a 12-inch full colour screen by the end of the year.

The new technology utilises a plastic called a light-emitting polymer (LEP), which is formed into pixel-like dots that glow when excited by a charge of as little as 5 volts. The LEPs, also called conjugated accidentally at the Cavendish Laboratory of Cambridge University in 1989. The British school owns 25 per cent of Cambridge Display Technologies, which holds worldwide patents on the specific LEP (poly p-phenylenevinylene) and has licensed it to Philips Electronics, among others. Seiko-Epson joined with Cambridge in November, 1996, and built a working prototype screen within six months. The Japanese company used its expertise in inkjet printing to deposit LEPs on a glass plate, and its knowhow in liquid-crystal-display production to make the thin-film switching electrode grid that lights the LEPs.

The partners claim that light weight, low power consumption, a thin profile, and flexibility would make LEP displays useful in portable devices such as PCs, camcorder and digital camera monitors, and even wireless phones. In fact, Philips says that it will build a portable phone with a small LEP screen this year.

Larger sizes, for television viewing, also are possible, Cambrigde says. According to the company, LEPs offer performance comparable with light-emitting diodes — namely the fast switching speeds needed to display motion video accurately. And compared with LCDs, the LEPs can be used to fashion larger panels at lower cost, don’t suffer from restricted viewing angles, and aren’t subject to the image lag that sometimes blurs fast action on LCDs. (Popular Science)

Ethyl alcohol from damaged apples
Indian scientists have developed a new method to produce ethyl alcohol, a chemical required for various commercial applications, using damaged, low grade and inferior quality apples.

Each year a large amount of apples perish in orchards due to inadequate storage and transportation facilities as well as diseases. Those fruits can be used for manufacturing ethyl alcohol. D. R. Modi from Faizabad-based Ram Manohar Lohia Avadh University says in a report in the Indian Journal of Experimental Biology.

Mature apples are highly susceptible to damage even on slight pressure. Seasonal diseases also add to the fruit loss causing not only economic loss but also environmental pollution.

Modi and his colleagues used two yeast strains sugar in the form of molasses and trace amount of urea to produce the alcohol from culled apples.

The yield is maximum when the sugar concentration varies from ten to 20 per cent, the report says.