- •1. Sort the fuels and energy sources below in the correct category.
- •2. Match these different power plants to their descriptions.
- •3. Read the text and answer the questions. Use these questions as a plan to retell the text.
- •4. Complete the word families in the table below.
- •5. Choose the correct form of the Infinitive.
- •6. Translate into English. Mind the syntactical functions of the Infinitive.
- •7. Study the diagram below of a portable generator. Answer these questions using the
- •8. Read the text to check as many of the answers as you can. You will not find complete
- •9. Study this text on the four-stroke cycle. Then label each stroke correctly in Fig. 2
- •11. Translate the sentences. Pay attention to the use of the Complex Object.
- •12. Use the correct form of the Infinitive in brackets. Translate the sentences. Pay attention to the use of the Complex Subject.
- •13. Listen to a phone call between a journalist, Colin Maitland, and the public relations officer of the company elec, Maria Berger. Complete the journalist’s notes.
- •14. Read what people say about different fuels and energy sources. Which paragraph is
- •15. Say which of the above statements you agree with. Use phrases below.
- •16. Work with a partner. How do you rate these different types of power plant on a scale
- •19. Find equivalents of the following phrases in the texts “Electricity Generation” and “Portable Generator”. Then use these phrases to make your own sentences.
- •20. Translate the text from Russian into English.
- •21. Translate the text from English into Russian.
21. Translate the text from English into Russian.
Thermionic Generators
Thermionic generators produce electrical power by using electrons emitted from the surface of a material heated to a high temperature. These generators share with thermoelectric devices the characteristic that the working fluid is electrons; they differ in that the heated electrons are emitted into a vacuum rather than into a solid. Because of the high potential difference between the interior and exterior of a solid, i.e., the "work function", thermionic generators must operate at high temperatures. Their output voltage is correspondingly higher than thermoelectric converters, ranging from 0.5 to 3 volts.
Although still in early stages of development, thermionic generators offer promise as a power source for both military and commercial applications. First, however, materials with a high heat of vaporization combined with a low work function must be found. These materials must be capable of operating for long periods of time at temperatures up to 4,500 degrees F.
At present, the thermionic generator is a concept that promises to open up new areas in power generation at high-operating temperature. For military applications where compactness, light weight, simplicity, and high efficiency are required, this device offers promise for practical use.