3. Make word combinations from the following words. Translate them into Ukrainian.

Form, molecular, original, structure, shape, plastic, original, memory, dimensions, original.

4. Put the verbs in brackets either in Present Perfect or in Present Perfect Continuous Tense.

1. Thermoplastics just (to move back) toward their original shape.

2. These materials (to alter) their molecular structure since 2002.

3. Polymers (to assume) the deformed shape yet.

4. People (to use) plastics since 1980s.

5. Potential memory (to exist) in all thermoplastics since that moment.

6. Memory already (to be exploited) in several days.

7. The component just (to be deformed) at an elevated temperature.

5. Answer the following questions:

1. What is a plastic memory?

2. In what cases is this memory undesirable?

3. What phenomena does the change in mechanical properties of polymers result from?

4. List four ways of plastic memory exploitation.

Section 6

1. Read and translate the following text: fibres

Fibres are probably the oldest engineering materials used by man. Jute, flax, and hemp have been used for "engineered" products such as rope, cordage, nets, water hose, and containers since antiquity. Other plant and animal fibres have been used for felts, paper, brushes, and heavy structural cloth.

The fibre industry is clearly divided between natural fibres (from plant, animal, or mineral sources) and synthetic fibres. Many synthetic fibres have been developed specifically to replace natural fibres, because synthetics often behave more predictably and are usually more uniform in size.

For engineering purposes, glass, metallic, and organically derived synthetic fibres are most significant. Nylon is used for belting, nets, hose, rope, parachutes, webbing, ballistic cloths, and as reinforcement in tyres.

Metal fibres are used in high-strength, high-temperature, light weight composite materials for aerospace applications. Fibre composites improve the strength-to-weight ratio of base materials such as titanium and aluminium. Metal-fibre composites are used in turbine compressor blades, heavy-duty bearings, pressure vessels and spacecraft re-entry shields. Boron, carbon, graphite, and refractory oxide fibres are common materials used in high-strength fibre composites.

Glass fibers are probably the most common of all synthetic engineering fibers. These fibers are the finest of all fibers, typically 1 to 4 microns in diameter. Glass fibers are used for heat, sound, and electrical insulation; filters; reinforcements for thermoplastics and thermoset resins and for rubber (such as in tyres), fabrics; and fiber optics.

2. Find in the text English equivalents to the following words and word combinations:

волокно, джут, конопля, такелаж, шланг, фетр, синтетичні волокна, скло, ремені, тасьма, зміцнення, композитні матеріали, турбокомпресор, скловолокно, тепло, звуко та електроізоляція, нейлон, термопластик.

3. Make word combinations from the following words. Translate them into Ukrainian.

Animal, applications, bearings, natural, fibre, heavy-duty, thermoset, pressure, fibres, engineering, purposes, turbine, ratio, composite, insulation; materials, aerospace, strength-to-weight, industry, compressor, vessels, heat, fibres, resins.

4. Make up sentences from the following words and translate them.

1. Flax, have been use, jute, and hemp, for, such, as, “engineered”, products, rope, water hose, cordage, nets, since, antiquity.

2. Brushes, have been used, other, plant, fibers, and, animal, heavy, structural, and, close, paper, for, felts.

3. Synthetic, fibers, glass, common, fibers, of all, engineering, are, probably, the most.

5. Turn the following sentences from Direct Speech into Indirect Speech:

1. The scientist said: “Fibers have been already used as engineering materials for centuries”.

2. They declared: “The fiber industry is clearly divided between natural fibers and synthetic fibers”.

3. He declares: “For engineering purposes glass, metallic and organically derived synthetic fibers are the most significant”.

4. The engineer said: “Glass fibers are probably the most common of all synthetic engineering fibers”.

5. He said: “We used glass fibers for heat insulation”.