काँच की उपयोगता और दुर-उपयोगता के बारे मे जरुर जाने?
GLASS
CAPTURING THE DANCE OF LIGHT
A.
Glass, in one form or another, has long been in
noble service to humans As one of the most widely used of manufactured
materials, and certainly the most versatile, it can be as imposing as a
telescope mirror the width of a tennis court or as small and simple as a marble
rolling across dirt The uses of this adaptable material have been broadened
dramatically by new technologies glass fibre optics — more than eight million
miles — carrying telephone and television signals across nations, glass
ceramics serving as the nose cones of missiles and as crowns for teeth; tiny
glass beads taking radiation doses inside the body to specific organs, even a
new type of glass fashioned of nuclear waste in order to dispose of that
unwanted material.
B.
On the horizon are optical computers These
could store programs
and process information by means
of light - pulses from tiny lasers - rather than electrons And the pulses would
travel over glass fibres, not copper wire These machines could function
hundreds of times faster than today’s electronic computers and hold vastly more
information Today fibre optics are used to obtain a clearer image of smaller
and smaller objects than ever before - even bacterial viruses. A new generation
of optical instruments is emerging that can provide detailed imaging of the
inner workings of cells. It is the surge in fibre optic use and in liquid
crystal displays that has set the U.S. glass industry (a 16 billion dollar
business employing some 150,000 workers) to building new plants to meet demand.
C.
But it is not only in technology and commerce
that glass has widened its horizons. The use of glass as art, a tradition spins
back at least to Roman times, is also
booming. Nearly everywhere, it
seems, men and women are blowing glass and creating works of art. «I didn’t sell
a piece of glass until 1975, Dale Chihuly said, smiling, for in the 18 years
since the end of the dry spell, he has become one of the most financially
successful artists of the 20th century. He now has a new commission - a glass
sculpture for the headquarters building of a pizza company - for which his fee
is half a million dollars.
D.
But not all the glass technology that touches
our lives is ultra-modern. Consider the simple light bulb; at the turn of the
century most light bulbs were hand blown, and the cost of one was equivalent to
half a day’s pay for the average worker. In effect, the invention of the ribbon
machine by Corning in the 1920s lighted a nation. The price of a bulb plunged.
Small wonder that the machine has been called one of the great mechanical
achievements of all time. Yet it is very simple: a narrow ribbon of molten
glass travels over a moving belt of steel in which there are holes. The glass
sags through the holes and into waiting moulds. Puffs of compressed air then shape
the glass. In this way, the envelope of a light bulb is made by a single
machine at the rate of 66,000 an hour, as compared with 1,200 a day produced by
a team of four glassblowers.
E.
The secret of the versatility of glass lies inits interior structure. Although it is rigid, and thus like a solid, the atoms
are arranged in a random disordered fashion, characteristic of a liquid. In the
melting process, the atoms in the raw materials are disturbed from their normal
position in the molecular structure; before they can find their way back to
crystalline arrangements the glass cools. This looseness in molecular structure
gives the material what engineers call tremendous “formability” which allows
technicians to tailor glass to whatever they need.
F.
Today, scientists continue to experiment with
new glass mixtures and building designers test their imaginations with
applications of special types of glass. A London architect, Mike Davies, sees
even more dramatic buildings using molecular chemistry. “Glass is the great
building material of the future, the «dynamic skin»,’ he said. “Think of glass
that has been treated to react to electric currents going through it, glass
that will change from clear to opaque at the push of a button that gives you
instant curtains. Think of how the tall buildings in New York could perform a
symphony of colours as the glass in them is made to change colours instantly.”
Glass as instant curtains is available now, but the cost is exorbitant. As for
the glass changing colours instantly, that may come true. Mike Davies’s vision
may indeed be on the way to fulfillment.
Questions 1-5
Reading Passage 1 has six paragraphs (A-F). Choose the most
suitable heading/or each paragraph from the list of headings below. Write the
appropriate numbers (I -x) in boxes 1-5 on your answer sheet.
NB There is more headings than paragraphs so you will not
use all of them. You may use any heading more at once.
List
of Headings
1.
Growth in the market for glass crafts
2.
Computers and their dependence on glass
3.
What makes glass so adaptable
5.
Scientists’ dreams cost millions
6.
Architectural experiments with glass
7.
Glass art galleries flourish
8.
Exciting innovations in fibre optics
9.
A former glass technology x Everyday uses of
glass
|
1.
Paragraph A
2.
Paragraph
B
3.
Paragraph C
4.
Paragraph D
5.
Paragraph E
Questions 6-8
The diagram below shows the principle of Coming’s ribbon
machine. Label the diagram by selecting NO MORE THAN THREE WORDS from
the Reading Passage to fill each numbered space. Write your answers in boxes
6-8 on your answer sheet.
Questions 9-13
Look at the list below of the uses of glass. According to
the passage, state whether these uses exist today, will exist in the future or
are not mentioned by the writer. In boxes 9-13 write
A.
If the uses exist today
B.
if the uses will exist in the future
C.
If the uses are not mentioned by the writer
9 dental fittings
10 optical computers
11 sculptures
12 fashions
13 curtains
Comments
Post a Comment