Metod_англ.мова_

6.The relationship between man and nature …. one of the major problems facing civilization today (become, has become, became).

7.The future plant … more controllable (will be, are, to be)

8.A highly … heavy industry is the first essential for the build-up of an …. economy (developing, developed, develop / advanced, advancing, advance).

9. Engineering in our country is not an industry but a complex …. of a hundred of ….industries such as machine-tool manufacture, automobile construction, instrumentmaking and power engineering (consisted, was consisted, consisting / interlinking, will link, interlinked).

10. Numerically … machines …. on microprocessors and microcomputers are being introduced on a large scale (controlling, controlled, was controlling / are based, base, based).

V Translate the following word-combinations from English into Ukrainian:

1.electrical copper

2.pure copper

3.annealed copper

4.chromium copper

5.casting copper

6.sheet copper

7.native copper

8.high-conductivity copper

9.Bessemer copper

10.tough-pitch copper

VI Give summary of the text and be ready to speak on the topic.

Use of Non-ferrous Metals in Precision Presswork and Tooling

Non-ferrous metals are those metals which does not contain iron. They are not magnetic and are usually more resistant to corrosion than ferrous metals. Most commonly used non-ferrous metals are aluminum, copper, brass, lead, tin, gilding metal and zinc. Aluminium is a widely used non ferrous metal. It is grayish-white in colour, soft and malleable. This non ferrous metal is conductive to heat and electricity. It is corrosion resistant. Aluminium can be welded but this is difficult. Special processes need to be adopted in order to weld it properly. Due to its light weight, it is used in the manufacturing of aircrafts and boats. Its other uses are window frames, saucepans, packaging and insulation, pistons and cranks.

Aluminium alloys (Duraluminium) is composed of aluminium, copper and manganese. Its also ductile, malleable, work hardens. It is used in the manufacturing of aircrafts and vehicle parts.

Copper is another very important pure non ferrous metal. It’s red in colour, tough and ductile. It is a very good electrical conductor and offers great resistance to corrosion. Copper can work hard or cold but it needs frequent annealing. Copper is mostly used in the manufacturing of electric wires, cables and conductors. Its other uses

are water and central heating pipes and cylinders, printed circuit boards and manufacturing of special roofs.

Brass. Another important non ferrous metal is brass which is not a pure metal but combination of Copper and Zinc. It contains 65% copper and 35% zinc. This nonferrous metal is very corrosive, yellow in colour, tarnishes very easily. It is harder than copper and it’s a good electrical conductor.

Lead is a pure and an important non-ferrous metal. It is the heaviest common metal. The other characteristics are its softness, malleability and brightness. It has resistant to corrosion. Its uses are different than other non ferrous metals. It is used in protection against X-ray machine, paints, roof coverings, flashings etc.

Zinc is also a pure and an important non-ferrous metal. A layer of oxide protects it from corrosion. It is bluish-white in colour and easily worked. It is used to makes brass by mixing and processing with copper. It is used as coating layer for steel tanks, buckets.

Tin is a pure non-ferrous metal. It is white in colour, soft and corrosion resistant. It is used in tinplate and making bronze.

Gilding metal. This non-ferrous metal comprises of 85% copper and 15% zinc. It is corrosion resistant, golden in colour and enamels well. Its uses are beaten metalwork and artificial jewellery manufacturing.

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: )

Grammar: Tense Forms in Passive. Modals (Review).

Read the text and translate it in writing.

Problem of engineering materials

Each year several thousand mechanisms, instruments and devices of various kinds are introduced into production.

The complexity and precision of modern machines and mechanisms have increased so rapidly that the technological servicing of their designing and production is a very complicated problem. Their quality and reliability depend upon many scientific disciplines, among them the science of materials. This might well be called the age of materials science.

It is very important that specialists should have information on the properties of materials subjected to most severe conditions of temperature, loading, corrosion, etc.

The rate of our progress in such different fields as space research, nuclear power engineering, in such technologies as laser and plasma technologies, powder metallurgy, self-spreading high-temperature synthesis, and others would be impossible without a

complete knowledge of the properties of various engineering materials, without the development of new materials and old materials with new properties.

A deep and versatile knowledge of the properties of engineering materials would not only be needed by engineers and engineer-designers to prevent machine breakage, failure of structures, but such knowledge would be also necessary in order that these materials should be used most economically. It is a fact that some materials are available in insufficient quantities and the more effective use of new substitute materials should be made.

Modern industry requires materials capable of working in diverse conditions. Research establishments are in constant search of such materials, for example, studying optical strength with the help of a laser beam, testing building materials for thermal shock, etc. They have developed many alloys, ceramics or plastics reinforced with metal, glass, etc. Such materials find application in all spheres of technology, science and in everyday life.

It was only at the beginning of this century that research began in the physics of strength of materials, and the materials science appeared. The problem of properties of materials is hidden deep in the mysteries of atomic and molecular structure, and it took a long time before they could be mastered. The materials science has led to the development of many new materials having better engineering properties.

Answer the fallowing questions:

1.What quality and reliability of engineering products depend upon?

2.Why is it necessary for an engineer to know the properties of materials?

3.What can happen if the properties of materials are not taken into account by the designer?

4.What engineering materials have been developed by modern materials science?

5.What scientific achievements help materials science?

IV Choose the right variant from the given in brackets.

1. Research in strength of materials ... in our country by many scientists (to be conducted, is conducted, were conducted).

2. Every engineer ... the properties of engineering materials (had to know, could know, should know).

3. ... take into account such characteristics of engineering materials as strength, stiffness, ductility, elasticity, fatigue resistance and corrosion resistance (will, should, must).

4.These conditions ... taken into account in the design of such constructions as gas and steam turbines for ships, rockets, jet engines and various equipment for atomic power station (is, should be, shall be).

5.He ... to finish this design as soon as possible (could, must, had).

6.Free – of waste production ... developed to harmonize the relationship between man and nature (have to be, w re, must be).

7.Transistors ... of small germanium crystals (is made, have made, are made).

8.Laser energy ... transformed practically without loss into many familiar forms of energy (are, is, were).

9.The particles called molecules cannot ... without changing the nature of the substance (be divided, was divided, are divided).

10.The high-silica glasses can ... red and water quenched without cracking (be heat, be heated, be to heat).

V Translate the following word combinations from English into Ukrainian:

1.impact strength

2.weld strength

3.compression strength

4.tensile strength

5.torsion strength

6.fatigue strength

7.shear strength

8.creep strength

9.crack strength

10.high-temperature strength

VI Give summary of the text and be ready to speak on the topic.

History of Mechanical Engineering

The history of mechanical engineering can be traced directly to the ancient world, to the designers and inventors of the first mechanisms which were powered by human or animal labour, water or wind energy, or a combination of these.

Although many of the mechanisms had a purely peaceful application, such as for flight, irrigation or building, the word "engineer" originally meant "military engineer" because it was derived from the term "engines of war". These were machines such as catapults, floating bridges and assault towers. The invention of the steam engine in the latter part of the 18th century provided a key source of power for the Industrial Revolution and gave enormous impetus to the development of machinery of all types.

As a result, a new major classification of engineering dealing with tools and machines, namely mechanical engineering, received formal recognition in 1847.

Today's mechanical engineer is heavily involved in the development and use of new materials and technologies, especially in computer aided engineering. A rapidly growing field for mechanical engineers is environmental control, comprising the development of machines and processes that will produce fewer pollutants, as well as the development of new equipment and techniques to reduce or remove existing pollution. Although mechanical engineers may occasionally work alone on a small project, they are working on large projects, cooperating with specialists from other areas.

In almost every sphere of modern life, from the air-conditioned office or home to the modern industrial plant or mode of transport, one sees the work of mechanical engineers who continue to develop and apply new knowledge and technology to improve the quality of life for society as a whole.

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: ) II

Grammar: Tense Forms in Passive. Modals (Review).

I Read the text and translate it in writing.

Knowledge of the Properties of Engineering Materials is Very Important.

An airliner crashes into a mountain, a train is wrecked, a bridge fails, and the loss of life and the cost of destruction may sometimes be the responsibility of the engineer. To avoid these possibilities, engineers must not only know how to determine the stresses and deformations in structures and machines under a variety of possible loading conditions, but they should also know how well the selected material of construction is to resist the loading.

In our daily lives we are constantly faced with the importance of finding suitable engineering materials. A complete knowledge of the properties of engineering materials would not only be required by engineers to prevent failure of structures and machines, but such knowledge would be also necessary in order that these materials should be made use of most economically. In recent years, the fact that some materials are available in insufficient quantities and the more effective use of new substitute materials required that a more thorough consideration of material properties be made. The science of engineering materials has led to the development of many alloys having much greater resistance to various loading conditions.

For many products made of nonmetallic materials such as, for example, the tremendous amount of things manufactured using plastics, a consideration of engineering properties might be very important. It is often required that we should get information on the properties of materials subjected to most severe conditions of temperature, corrosion, etc,

These conditions should be taken into account in the design of such constructions as gas and steam turbines for ships, rockets, jet engines, and various equipment for atomic power stations.

The development of materials required for the construction of the many machines, structures and products used in our modern civilization is provided by many kinds of engineers and scientists. In selecting the most suitable material and in the determination of the sizes of the required members, the designer might utilize the services of a materials engineer.

II Answer the following questions:

1.What should engineers know to avoid the possibilities of destruction of machines and constructions?

2.Why is a thorough consideration of material properties so important?

3.What are the achievements of engineering materials science?

4.What conditions should be taken into account in the design of different constructions and equipment?

5.What is the role of a materials engineer in the modern designing?

IV Choose the right variant from the given in brackets.

1.The problem of properties of materials ... in the mysteries of atomic and molecular structure, and it took a long time before they ... (is hidden up, hidden up, are hidden up/ will be mastered, could be mastered)

2.One ... to be careful when experimenting with inflammable materials (should, must, ought).

3.Careful attention ... be paid to the construction of this unit (ought, must, have to).

4.Every engineer ... know the properties of engineering materials (had, could, should).

5.The design of machine parts … upon the limiting conditions (must be based, must base, will be based).

6.The crystalline solids … chiefly in an elastic way by very small amounts (is compressed, was compressed, are compressed).

7.The crumbling through the external pressure of fluid … the structure of weaker materials, such as marble and sandstone (must destroy, can destroy, should destroy).

8.Environmental protection policies must … to the state level in all countries (be raised, raise, raised).

9.The document at the Vienna meeting … by heads of the delegations from 46 states (were signed, will be signed, was signed).

10.The conflict between man and nature … by fostering a scientific ecological education, encouraging all people to take an active part in nature protection (can avoid, can be avoided, can avoided).

V Translate the following word combinations from English into Ukrainian:

1.impact strength

2.weld strength

3.compression strength

4.tensile strength

5.torsion strength

6.fatigue strength

7.shear strength

8.creep strength

9.crack strength

10.high-temperature strength

VI Give summary of the text and be ready to speak on the topic.

Engineering Materials

Materials are substances from which something is composed or made from. Let us consider engineering materials used in building our material world: building construction, roads, bridges, irrigation systems, pipelines, machines, transportation equipment, electricity systems, tools, furniture, communication facilities, instrumentation, and various utilities and appliances both at home and in the office.

Materials are central to the growth, prosperity, security, and quality of human life. Throughout history, the development of human civilization has been closely tied to materials which have been produced and used in society. The levels of involvement have been designated according to the materials used. In early human civilization, people used materials existing in nature such as stones, wood and clay. This period became known as the "Stone Age". In time, techniques to produce materials having properties superior to those occurring naturally were discovered. With the Industrial Revolution, modern heavy industries were based largely on iron, steel and other metals,

and this became known as the "Metal Age". Only recently scientists have begun to study the relationships between the composition, structure and properties of materials. The knowledge of engineering materials has enabled us to design and create the numerous materials necessary to meet the needs of technological society.

Material scientists and engineers now have ability to tailor materials from the atomic scale to obtain desired properties. A new age in materials has been used to describe the revolutionary changes in materials science and engineering, as well as their impact on society. For example, advanced composites have been developed to combine the properties of high stiffness, strength, toughness and low density to meet special structural requirements. Surface treatments, including the development of various coatings and surface modification techniques, provide a combination of extreme hardness, wear, corrosion and high temperature resistance. Artificial layered structures offer limitless possibilities for creating new electronic and semiconductor devices. We now face exciting and dramatic changes in the materials world, giving our industries and society endless developmental opportunities.

5

: )

Grammar: Tense Forms in Active (Review)

I Read the text and translate it in writing.

Electric Circuits

The concepts of electric charge and potential are also essential in the study of electric currents. When an extended conductor has different potentials at its ends, the free electrons of the conductor itself are caused to drift from one end to the other. In order for this flow to continue it is necessary that the potential difference be maintained by some electrical source such as an electrostatic generator, or, much more frequently, a battery or a direct-current generator. The wire and the electrical source together form an electric circuit, the electrons drifting around it as long as the conducting path is maintained. In effect such a flow of electrons constitutes an electric current.

Batteries and direct-current generators are sources of potential difference which urge the electrons around a circuit continually in one direction, producing a unidirectional current. For this reason such a source is said to have a fixed polarity, one terminal being called positive and the other negative. If it is desired to reverse the flow, then the terminals of the circuit must be reversed with respect to the source.

From the early days of electrical science, current has been regarded as a flow of electricity from the positive terminal to the negative terminal in the external circuit connected to a source. Now we know a current through a conductor to be actually a

movement of electrons, and since these have negative charges, they travel around the external circuit from the negative terminal to the positive terminal. The electron flow is, therefore, opposite to the conventional direction of current, making it necessary, in order to avoid confusion, to distinguish ore from the other by name.

II Answer the following questions:

1.What are essential in the study of electric current?

2.What do form an electric circuit?

3.What does constitute an electric current?

4.When must the terminals be reversed with respect to the source?

5.How is a current known in our days?

IV Choose the right variant from those given in brackets:

1.Atoms ... electrons which are negatively charged, protons which are positively charged and neutrons which have no charge. (contains, contain, contained)

2.Common sources of electricity ... batteries and power plants. (is, are, to be)

3.Electricity ... through transmission lines to houses, factories (to flow, flows, flowed)

4.Such free electrons ... always present in metals. (is, are, to be)

5.People always ... their surroundings (polluted, to pollute, were polluting)

6.A generator is a machine that ... mechanical energy into electrical energy. (converts, were converting, to convert)

7.These coils ... the magnetic lines of force. (to cut, cut, cuts)

8.Pollution ... streams, lakes unpleasant to swim in or to have a rest. (to make, makes, were making)

9.A typical commutator ... of commutator bars. (consists, to consist, consist)

10.Because series generators ... poor voltage regulation, only a few are in use (has, have, to have)

V Finish the following sentences according to the text:

1. ... are also essential in the study of electric currents. 2. In effect such a flow of electrons ... .

3. ... then the terminals of the circuit must be reversed with respect to the source.

4.When an extended conductor has different potentials at its ends ...

5.The electron flow is ...

6.The wire and the electrical source together ...

VI Give summary of the following text and be ready to speak on this topic.

There are a variety of amplifier designs that couple a class AB output stage with other more efficient techniques to achieve a higher efficiency with low distortion. These designs are common in large audio amplifiers, for instance, since the heatsinks and power transformers would be prohibitively large (and costly) without the increase in efficiency. The terms "class G" and "class H" are used interchangeably to refer to different designs, varying in definition from one manufacturer or paper to another.

Class G amplifiers are a more efficient version of class AB amplifiers, which use "rail switching" to decrease power consumption and increase efficiency. The amplifier has several power rails at different voltages, and switches between rails as the signal output approaches each. Thus the amp increases efficiency by reducing the wasted power at the output transistors.

5

: )I

Grammar: Tense Forms in Active (Review)

I Read the text and translate it in writing.

Electricity in Motion

When an electric charge is at rest, it is spoken of as static electricity, but when it is in motion, it is referred to as an electric current. In most cases, an electric current is described as a flow of electric charges along a conductor. Such is the case, for example, in the experiment of charging an electroscope from a distant point by means of a long copper wire and a charged rubber rod. This experiment is explained by stating that electrons already in the wire are pushed along toward the electroscope by the repulsion of electrons from behind.

To make an electric-current flow continuously along a wire, a continuous supply of electrons must be available at one end and a continuous supply of positive charges at the other. This is like the flow of water through a pipe; to obtain a continuous flow a continuous supply of water must be provided at one end and an opening for its escape into some receptacle at the other. The continuous supply of positive charges at one end of a wire offers a means of escape for the electrons. If this is not provided for, electrons will accumulate at the end of the wire, their repulsion back along the wire stopping the current flow.