World’s largest construction project!
Jagvir Goyal

WHEN creating something even small in magnitude may bring immense satisfaction to a person, the heady feeling that the engineers might have felt on completion of world’s largest construction project would have been something beyond description and worth actual experience only!

The project is Chek Lap Kok International Airport, Hong Kong. Built at a whooping cost of Rs 84000 crore, the airport has been completed only recently to its full capacity and in a time span of just nine years. That is equivalent to spending Rs 9300 crore per year! Comparing with this, the massive Ranjit Sagar Dam project built at a cost of Rs 3800 crore in a period of 25 years looks insignificant. Taking cost as the key factor, it can be worked out that the machinery and manpower deployed at Hong Kong, international airport was more than 58 times than that used on the RSD project.

Chek Lap Kok International Airport has also been voted as the Best Asian Project of the 20th century. The assessment has been carried out by the prestigious US based organisation CONEXPO. It has also received the title of world’s largest construction project and has figured among the 10 best projects of the world.

Spread over an area of 1248 hectares, this Hong Kong airport now handles 45 million passengers a year on an average. In year 2000, it handled 87 million passengers! That means handling 2.5 lakh passengers and their luggage every day. The number of flights per day is 460, going up to 560 on a particular day. The airport is no less than a visitor’s paradise and a tourist spot in itself, such swift and immaculate are its services and so fresh and clean are its buildings and surroundings.

The layout resembles the shape of an aeroplane.Built on the Chek Lap Kok island, 25 km from Central Hong Kong, 75% of its site area was formed by a massive reclamation from the sea. The site preparation itself took 31 months i.e. 25% of the total time period. For it, 347 million cubic-metres of material was handled 4 lakh cu.m. of rock, mud, sand and soil was removed every day at a rate of 17000 cu.m. per hour or say nine tonne of material per second. The project involved one of the largest earth moving operations ever taken up in the world in such a short time. The airport has an eight level unique design with four of its levels devoted to a highly efficient and effective transportation system. Level 5 accommodates the arrivals, level 6 is for boarding, level 7 is to check-in while level 8 has miscellaneous airport facilities and offices.

As the airports are mostly located away from the city areas, their utilisation and efficiency depends upon the transportation system connecting them to the cities around them. Excellent transportation network has been created at the Hong Kong International Airport. This airport has the rare facility of a direct connection with the railway network! The trains connecting the downtown Hong Kong to the airport run at a 10 minute interval and cover a distance of 34 km in just 23 minutes. The four level ground transportation centre accommodates the Airport Express Railway Station in addition to other public transports such as taxis, buses, tour coaches, hotel limousines and private cars. Even perry service is made available at the ferry pier of the airport.

Cyber break cafes, multimedia lounges and wireless LAN services are abundantly available at the airport. Most of these services are free, never allowing the passengers to go out of touch with the world while waiting for their flights. In addition, there are multimedia pay phones which keep one connected to the world of dot com.

The passenger terminal complex of the airport can be reckoned as its best engineering feature. This 1.27 km long Y-shaped building has an area of 5,50,000 sq. m. It accommodates 70 moving walkways, 10400 luggage trolleys, 92 lifts and 68 escalators. There are 140 commercial, food and beverage outlets in it. Though the airport handles 1.5 to 2.5 lakh passengers and their luggage in a day, the terminal complex is so designed that the pedestrian flow for arrivals and departures is free of hassles. Signage is frequent and prominent to guide the passengers.

Extensive use of exposed structural steel has been made in the terminal complex. Only the roof structure has consumed 15000 metric tonne of fabricated steel. Tall, circular concrete columns built over a grid of 36mX36m support a 400 mm deep shell roof. The sky lights provided in the shell roof allow the daylight to come in which is reflected by light reflectors to fully illuminate the inside of the complex. Abundant use of glass has been made in the building. The glass lift shafts, glass walls, glass balustrades and partitions further reflect the reflected daylight adding brightness to the interiors. An efficient and unobtrusive air-conditioning system adds comfort and ambience to the massive 550000 sq. m. area.

There are two runways having a total length of 3800 metres. 48 frontal aircraft gates and 27 Aprons ensure smooth movement of aircrafts. Adjacent to the passenger terminal, a 1100 room hotel has been constructed. A large workforce of 45000 has been deployed to manage the airport.

World’s largest construction project should be a source of inspiration for the Indian engineers. Completion of this Rs 84000 crore project in just nine years proves that today, nothing is impossible and also that we have miles to go to come at par with international standards. As the project has proved commercially viable, the arrangement of such a large capital and economics of its return should be studied by the economists.

Synchrotron radiation as an excellent tool
Nataraja Sarma

JUST before World War II started, cosmic rays from outer space were discovered to bombard the earth. Homi Bhabha and Heitler worked out how these rays caused showers of atomic particles as they entered the atmosphere of the earth. Very soon, physicists realised that a great deal of new physics information could be gained from the collisions of high energy electrons with matter. However, the intensity of cosmic rays was not enough to give significant results and the best way to get higher intensities of high energy electrons was to build big accelerators

The cyclotron was the first such machine, but soon it became apparent that it was far more economical to build a synchrotron. In this machine the electrons travel in a circular orbit of constant radius, making the design of the vacuum tube and of the magnets simpler and smaller. All large machines work on this principle now. Soon after General Electric of USA built the first electron synchrotron in 1947, they found that the electrons radiated energy as light when they sped round in their orbit and this limited the maximum energy of the machine.

Synchrotron radiation is emitted when electrons approaching the speed of light are deviated from their course by a bending magnet. The radiation comes out as an intense and well focused beam of small size, typically about 1 sq.mm, rather like laser light. It is now believed that in outer space, electrons spiral round magnetic fields and so emit what we see as strong radio emission from celestial source such as the Crab nebula.

Scientists soon realised that synchrotron radiation was an excellent tool that might replace the traditional X-ray diffraction methods which were initiated by von Laue and Bragg and were so successful in unraveling the secret of the DNA molecule. The light from early machines was not intense enough to be useful but developments over the last 50 years have made synchrotron light a powerful tool to study how atoms arrange themselves in molecules and in crystals.

Storage rings where the current of electrons builds up within the accelerating tube helped to increase the light intensity. Since the intensity and focussing of synchrotron light improves as the electron energy increases, storage rings were made larger and larger. Now the radiation covers the full spectrum from the infrared to X-rays with maximum energy in the X-ray region. There is also the added advantage that the light is polarised and, like laser light, is coherent.

The quality of synchrotron light is measured in terms of a parameter — “brilliance” which combines the intensity and focus of the radiation. The brilliance of modern sources is a million million times that of a conventional X-ray source! It is unsurpassed as a spectroscopic source in the vacuum ultraviolet and X-ray regions of the electromagnetic spectrum. The short wavelengths of the X-rays give better resolution during experiments on imaging, scattering and absorption spectroscopy. With synchrotron radiation one can scan a range of energies using a beam line monochromator, even during an experiment.

The brilliance is achieved by using wobbler or undulators in modern synchrotrons. PTI

NEW PRODUCTS & DISCOVERIES

Cancer caught on life-saving camera

Researchers have developed a new device to show exactly when cancerous cells are beginning to burrow through the skin and invade the body.

With early diagnosis, the deadliest form of cancer, malignant melanoma, that kills 1000 people in a year in UK alone is completely curable. The new device, called SAI scope, will help doctors in immediately telling when a mole is invading deeper into the skin than normal and thus facilitate early therapy.

SIA scope, based spectrophotometric intracutaneous analysis (or SIA) which has been researched at Birmingham University, in the English Midlands over the past 10 years, uses harmless light along with sophisticated computer software to construct an image of each part of the skin including possible cancerous cells.

Doctors can then use this information to help in their diagnosis, saving patients the anxiety of unnecessary surgery saving hospital time and money. PTI

Biocide from croton seed

A biocide formulation obtained from the croton seeds has been found effective in preventing bio-fouling by containing the growth of microbes, often a problem in cooling water.

Scientists in Cochin University of Sciences and Technology in Kochi prepared a biocide from seeds of croton (Croton tiglium), an evergreen tree with smooth, ash-coloured bark, yellowish-green leaves and small flowers cultivated in Bengal, Assam and South India. They studied its efficacy in arresting the growth of bacteria, algae and fungi which cause fouling.

The croton seed oil is a glyceryl ester in which a toxic resin and toxic proteins are dissolved. It has irritant rubefacient and cathartic properties due to which it has been used by people in the countryside for fish catching and pest control for years, a report in the Journal of Scientific and Industrial Research said.

Cooling water is essential for cooling machines like compressors, pumps, blowers and heart exchangers. It is confined to a system called cooling tower where it is dozed with different chemicals to avoid corrosion and etching of metal parts.

However, unwanted growth of microorganisms in this water is often an irritant to prevent which biocides like methylene-bisthiocynate and dibromo nitrilopropionamide are added. These chemicals are toxic, carcinogenic and mutagenic, posing health hazards to the operating personnel and to environment. Besides, bacteria get immune to these chemicals on continuous use. PTI

SCIENCE QUIZ

J.P. GARG TESTS YOUR IQ

1. Who performed the first successful transplantation of a human organ in 1954 for which achievement he shared the Nobel Prize 36 years later? Which organ did he transplant?

2. NASA will soon send about 1,000 space probes (each weighing about a kilogramme and loaded with sensors) to explore the asteroid belt, present between the orbits of Mars and Jupiter. The mission, equipped with computers to analyse data, is called ANTS. Can you tell the full name of this mission?

3. To learn about an animal’s behaviour, scientists study the frequency, pitch, loudness, duration etc of sounds produced by the animal. What is this type of study called?

4. White metal is an alloy of tin, copper and phosphorus. It is difficult to distinguish it from silver by merely looking at the two as they resemble in appearance. Can you suggest a simple laboratory method (without chemical analysis) to distinguish between the two?

5. The Central Scientific Instruments Organisation, Chandigarh, has recently developed a “low vision aid” (LVA) for use by those persons whose vision has deteriorated to such an extent that they would require very high power and highly expensive lenses. The acrylic lenses developed by CSIO for LVA are not only reasonably priced but also have excellent image quality. What are these lenses called?

6. UHMWPE is a plastic-type material used in bone implants. What is the full form of UHMWPE?

7. Chlorophyll gives green colour to the plant leaves. Which pigments present in the leaves are responsible for their orange any yellow colours?

8. The computer input device “mouse” is used to control the movement of a cursor or pointer on the computer screen. Who invented this device and in which year?

9. We use five main products which come from insects. Four of these are honey, bee-wax, cochineal and lac. Which is the fifth?

10. Scientists have recently identified the longest ever tail of a comet which is more than 570 million km in length, nearly four times the distance between earth and sun. To which comet does this tail belong?

Answers
1. American surgeon Joseph Murray; kidney 2. Autonomous Nano Technology Swarm 3. Bioacoustics 4. Find their densities; The density of silver is sufficiently more than that of white metal 5. Aspheric lenses 6. Ultra High Molecular Weight Polyethylene 7. Carotene and xanthophyll 8. US computer engineer Douglas Engelbart in 1968 9. Silk 10. Comet Hyakutake.