8.Essential vocabulary:
to designate - to specify, to describe as
community - body of people living in the same locality
to confer - to grant, to bestow
to wield - to control, to sway
negligently - carelessly
maliciously - with wrongful intention
to enlighten - to instruct, to inform
benevolent - desirous of doing good, charitable
implicit - implied through not plainly expressed
waste disposal - getting rid of useless by-products of manufacture
to contaminate - to pollute, to infect
consensus - agreement
lack - deficiency, want, need
hereditary - transmitted from one generation to another
species - a group into which animals, plants, etc. that are able to breed with each other are divided
to alter - to change in character
to pursue - to proceed, to continue, to go in pursuit
to disseminate - to spread, to scatter
to engender - to give birth, cause
to accentuate - to emphasize
to impoverish - to make poor
inappropriate - not suitable
to sustain - to uphold, to support, to keep from falling
to mesmerize - to hypnotize
presupposition - thing assumed beforehand as basis of argument; assumption
acquisition - act of acquiring
9. Check your understanding answering the questions (use a dictionary if needed):
What indicates the centrality of technology in the life of mankind?
What are the stages of technological development of the primitive communities?
What does the Prometheus myth remind us?
What can be used to destroy as well as to create? Give some examples.
When has the pace of technological development increased dramatically?
Problems of which waste disposal are most serious?
What does genetic engineering open up?
In your opinion, should experiments on human genetic material be allowed?
Is it appropriate to speak of informational revolution?
What are the ways of assisting developing countries?
What problems is this assistance connected with?
What do science and technology involve as practices?
Texts for Additional Reading.
PERSONAL COMPUTER
The first personal computer, the Altair, was introduced in 1975. Only electronics hobbyists bought these computers.
In 1977, two American students, Steven P. Jobs and Stephen G. Wozniak, founded the Apple Computer Company and introduced the Apple II personal computer. The Apple II was much less expensive than mainframes. As a result, computers became available to people other than computer specialists and technicians. Millions of individuals, families, and schools also bought them.
In 1961, IBM entered the personal computer market with its PC. The machine was even more successful than the Apple II. Apple scored another success in 1984 with the introduction of its Macintosh, a powerful, easy-to-use desktop computer.
As computer power increased, so did computer speed. These increases were accompanied by a steady reduction in both size and cost. Modern personal computers are more powerful than UNIVAC I and can be purchased for less than $ 1,000.
A notebook computer is a portable computer that usually weighs less than 5 pounds (2.3 kilograms)
FUNDAMENTALS OF COMPUTER TECHNIQUES
There are three kinds of computers: digital, analogue and
hybrid.
An analogue computer computes by using physical analogue of numerical measurements.
A digital computer computes by using numbers or digits.
A hybrid computer is a machine which combines some of the properties of digital and analogue computers.
Invention of electronic computers is one of the greatest achievements of mankind. The significance of it can be compared with the invention of the steam-engine and the utilization of atomic energy.
Hundreds of computers are already in daily use. They penetrate almost into all spheres of our modem society, from nuclear energy production and missile design to the processing of bank checks, weather forecasting, manufacturing, research and medical diagnoses.
KINDS of COMPUTERS
A computer is really a very specific kind of counting machine. It can do arithmetic problems faster that any person alive. By means of electric processes it can find the answer to a very difficult & complicated problem in a few seconds. A computer can "remember" information you give it. It keeps the information in its "memory" until it is needed. There are different kinds of computers. Some can do only one job. These are special-purpose computers. Each specific problem requires a specific computer. One kind of computer can help us build a spaceship, an other kind can help us navigates it a special-purpose computer is built for this purpose alone & can't do anything else. But there are some computers that can do many different jobs. They are called the general-purpose computers. These are the big "brains" that solve the most difficult problems of science. We used to think of a computer as a large machine that took up a whole room. But today computers are becoming smaller & smaller. Though, these small devises are called microcomputers or minicomputers, they are still true computers.
The most important parts of a general-purpose computer are as follows:
memory, where information is kept
an arithmetic unit for performing calculation
a control unit for the correct order of operations
input devices
output devices for displaying the results of calculations.
The input & output devices are called peripherals. There are several advantages in making computers as small as one can. Sometimes weight is particularly important. A modem plane carries many heavy electronic apparatus. It is possible to make any of them smaller, it can carry bigger weight. But weight is not the only factor. The smaller the computer, the faster it can work. The signals go to & for at a very high but almost constant speed.
MACHINE LANGUAGE and PROGRAMMING.
The five units of the computer must communicate with each other. This they do by means of a machine language which uses a code composed of combinations of electric pulses. These pulse combinations are usually represented by ZEROS and ONES where the ONE may be a plus puke and the ZERO a minus pulse; or the ONE may be a pulse and the ZERO a no pulse.
Numbers are communicated between one unit and another by means of these ONE—ZERO or pulse — no-pulse combinations. The input has the additional job of converting information fed in by the operator into machine language. In other words, it translates from our language into the pulse — no-pulse combinations understandable to the computer. The output has the additional job of converting the pulse — no-pulse combinations into a form understandable to us, such as a printed report.
In addition to data, the input translates instructions needed to perform a given problem into pulse — no-pulse combinations. These instructions are originated by a programmer whose job it is to translate a scientific or business problem presented in human language into a sequence of detailed instructions understandable to the machine our lives: TV, calculators, mobile phones, CDs... It has also given us some household objects that make our lives easier and more comfortable.
TV. A Russian engineer Vladimir Zvorykin emigrated to the USA and there in 1931 produced an apparatus that later became known as a television set. The first TV station was located on the Empire State Building in New York City. The programmes could be watched only by those who lived not farther than 60 miles from the station.
Video. In 1975 the Japanese corporation JVC made it possible to record films and TV programmes at home. The system was known as VMS (Video Home System).
Computer. The first computers were huge. They were used for scientific purposes. Sinclair ZX 80, the 1980 machine, was the first computer used by ordinary people. Psion Organizer of 1990s shifted computers off the desktop.
Internet. The global network was designed for serious scientific purposes. In 1962 the US scientists started to build a network between the leading scientific centers of the USA. In 1969 this network joined four universities. In 1972 the first e-mail with the symbol @ was sent.
Mobile phone now used by millions of people appeared in 1973. The American Martin Cooper invented the first mobile phone — Motorola Dina-Tec. It weighed a kilo. But it took five years to draw in a commercial operator from Bahrain. Now mobile phones have made a massive impact on social and working activities and changed the way we communicate.
Compact Disc from the 1980s brought an end to vinyl records and Revolutionized the storage of computer data.
Digital Watch appeared on Roger Moore's wrist in1970.
SEMI-INSULATORS
Some materials are classified as semi-insulators. These have electrical conductivity nearer to that of electrical insulators. Semi-insulators find niche applications in micro-electronics, such as substrates for HEMT. An example of a common semi-insulator is gallium arsenide.
The property of semiconductors that makes them most useful for constructing electronic devices is that their conductivity may easily be modified by introducing impurities into their crystal lattice. The process of adding controlled impurities to a semiconductor is known as doping. The amount of impurity, or dopant, added to an intrinsic (pure) semiconductor varies its level of conductivity. Doped semiconductors are often referred to as extrinsic. By adding impurity to pure semiconductors, the electrical conductivity may be varied not only by the number of impurity atoms but also, by the type of impurity atom and the changes may be thousand folds and million folds. For example, a 1 cm3 specimen of a metal or semiconductor has of the order of 1022 atoms. In a metal every atom donates at least one free electron for conduction, thus 1 cm3 of metal contains on the order of 1022 free electrons. Whereas a 1 cm3 of sample pure germanium at 20 °C, contains about 4.2×1022 atoms and 2.5×1013 free electrons and 2.5×1013 holes (empty spaces in crystal lattice having positive charge). The addition of 0.001% of arsenic (an impurity) donates an extra 1017 free electrons in the same volume and the electrical conductivity is increased by a factor of 10,000.
PREPARATION of SEMICONDUCTORS MATERIALS
Semiconductors with predictable, reliable electronic properties are necessary for mass production. The level of chemical purity needed is extremely high because the presence of impurities even in very small proportions can have large effects on the properties of the material. A high degree of crystalline perfection is also required, since faults in crystal structure (such as dislocations, twins, and stacking faults) interfere with the semi conducting properties of the material. Crystalline faults are a major cause of defective semiconductor devices. The larger the crystal, the more difficult it is to achieve the necessary perfection. Current mass production processes use crystal ingots between 100 mm and 300 mm (4–12 inches) in diameter which are grown as cylinders and sliced into wafers.
Because of the required level of chemical purity and the perfection of the crystal structure which are needed to make semiconductor devices, special methods have been developed to produce the initial semiconductor material. A technique for achieving high purity includes growing the crystal using the Czochralski process. An additional step that can be used to further increase purity is known as zone refining. In zone refining, part of a solid crystal is melted. The impurities tend to concentrate in the melted region, while the desired material recrystalizes leaving the solid material more pure and with fewer crystalline faults.
In manufacturing semiconductor devices involving heterojunctions between different semiconductor materials, the lattice constant, which is the length of the repeating element of the crystal structure, is important for determining the compatibility of materials.
SEMICONDUCTORS
Such compounds share with better known semiconductors intermediate conductivity and a rapid variation of conductivity with temperature, as well as occasional negative resistance. Such disordered materials lack the rigid crystalline structure of conventional semiconductors such as silicon and are generally used in thin film structures, which are less demanding for as concerns the electronic quality of the material and thus are relatively insensitive to impurities and radiation damage. Organic semiconductors, that is, organic materials with properties resembling conventional semiconductors, are also known.
Silicon is used to create most semiconductors commercially. Dozens of other materials are used, including germanium, gallium arsenide, and silicon carbide. A pure semiconductor is often called an “intrinsic” semiconductor. The electronic properties and the conductivity of a semiconductor can be changed in a controlled manner by adding very small quantities of other elements, called “dopants”, to the intrinsic material. In crystalline silicon typically this is achieved by adding impurities of boron or phosphorus to the melt and then allowing it to solidify into the crystal. This process is called "doping".
In the classic crystalline semiconductors, electrons can have energies only within certain bands (i.e. ranges of levels of energy). Energetically, these bands are located between the energy of the ground state, the state in which electrons are tightly bound to the atomic nuclei of the material, and the free electron energy, the latter describing the energy required for an electron to escape entirely from the material.
СПИСОК ЛІТЕРАТУРИ :
A. Ashley. A Handbook of Technical Correspondence.-Oxford: University Press,1995.
Adrian Wallwork. Technician Options.- Oxford: University Press,2000.
Bondar Tamara. English Communication. ANNA MARIE: Центр навчальної літератури, 2004.
Michael Swan, Catherine Walter. How English Works.- Oxford: University Press,1998.
Priestly Barbara. British Qualification.-London, 1993.
Tribble Ch.Writing.- Oxford: University Press,2000.