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Grammar: Complex Subject
The low temperature physics deals with various phenomena occurring at temperatures in the region of absolute zero (-273єC). The lowest temperature on Earth is known to have been registered in the Antarctic – about -80єC. Still lower temperatures are claimed to be found on other planets. On Saturn, for instance, it reaches –153, on Uranus –173, on Neptune –193. On Pluto – the planet most remote from the sun- the temperatures appear to be below –218C. Even this, however, is believed not to be the limit. A temperature of –273єC has been found to be possible in nature. In laboratory experiments scientists have achieved a temperature, which differs from absolute zero by 1/10,000 of a degree.
Having learnt to control heat, man has multiplied its potential many times over, learned to cut and melt metal and found many other useful applications for it. Cold is considered to be quite useful.
The study of different substances at low temperatures has revealed many interesting phenomena. One of the most amazing (surprising) was superconductivity –the complete loss of resistance to electrical current. This pro perty has been found in more than 20 metals. If an electric current is sent through a ring of cooled metal of this type, it will circulate for a very long time.
Superconductivity has long been the subject of pure theory and it seemed that it would never be possible to apply it in practice. However, instruments have been developed using this phenomenon.
Of particular interest are the superconductive alloys widely applied in the development of superconductive magnets, which make possible, with a small expenditure of power, to obtain permanent magnetic fields of scores and hundreds of thousands of oersteds 1 .
Of great interest are recent theoretical studies that indicate the possibility of developing superconductors retaining their properties at room and even higher temperatures. Their practical application could open up a new chapter in the use of electric power. It could multiply the efficiency of electrical machines and save billions of kilowatt hours in transmitting power over long distances.
N O T E S
1.oersted [¶:sted] —1. ерстед , 2.одиниця магнітного опору.
I. Translate these word combinations into Ukrainian:
temperature limit, limit temperature, liquid helium, solid helium, re sistance loss, metal conductivity, room temperature, cooling system, laboratory experiments, television transmitters, power transmission, wave oscillation, low temperature physics, low temperature use, long distance transmission, large temperature differe nces, limit temperature use, power plant construction, transmission line efficiency, electrical control systems, cosmic radio communication, complete resistance loss, scientific research work, instantaneous frequency variation
II. Translate the following words, paying attention to the meaning of the prefixes super-, over- :
superconductivity, superconductive, superconductors, superhard, superfluidity, supersonic, overload, overflow
III. Translate these word combinations, paying attention to different meanings of the following words:
body, solid, field, develop, fail, range, degree
the body of a man, the body of a car, the body of a meteor; a solid state of matter, a solid building, a solid argument; an electric field, an oil field, coal fields, diamond f ields; to develop science, to develop different theories, to develop existing motors, to develop natural resources, to fail in an exam, a complete failure, the failure of a motor; a range of 20 kilometers, a range of problems, wave range, a short range.
IV. Translate these word combinations:
remote control, to control heat, to find useful applications, to subject to high pressure, to subject to high temperature, to occur at temperatures, in the region of absolute zero, to reach out to absolute zero, to become solid at temperatures close to absolute zero (near to), to fill quickly, to fill slowly, a surprising property, an important property, to apply superconductivity in practice, to apply superconductive alloys, to apply superhard metals, to deal with different phenomena, to deal with different problems, this book deals with.
V. Find synonyms in the following sentences and write them out:
1. Let’s choose p articular substances for our experiments. 2. It is necessary to select special techniques in dealing with this phenomenon. 3. The new express train runs at a speed of 160 km.p.h. 4. This is a fast train. 5. Solid helium is obtained by cooling and simultan eously subjecting it to high pressure. 6. One can get solid helium by cooling and at the same time by subjecting it to high pressure.
VI. Answer these questions:
1. What does this article deal with 2. What phenomena does low temperature physics deal with 3. At what temperatures do these various phenomena occur 4. Do they occur at temperatures in the region of absolute zero or not 5. What lowest temperature on Earth has been registered in the Antarctic 6. Are still lower temperatures claimed to be found on other planets 7. What is the temperature on Saturn 8. How many degrees of cold does the temperature reach on Uranus 9. How many degrees of cold does the temperature reach on Neptune 10. How many degrees of cold does the temperature reach on Pluto 11. Is –218 °C believed to be the limit of cold 12. What temperature has been found to be possible in nature 13. What kind of temperat ure have scientists achieved in laboratory experiments 14. What has man learned to do with metal 15. What other applications has man found for metals 16. Is cold cons idered to be quite useful or not 17. What was the result of the study of different substances at low temperatures 18. What is superconductivity 19. In how many metals has superconductivity been found
Translate the text using a dictionary
Liquid helium surprises
1. All solid bodies become brittle while liquids and gases become solid at temperatures close to absolute zero. There is only one gas – helium which fails to solidify on cooling alone. Solid helium is obtained by cooling and simultaneously subjecting it to high pressure.
2. At temperatures near to absolute zero, liquid helium reveals a surprising property – sup er fluidity. This phenomenon, discovered by Pyotr Kapitza, defies all conventional concepts of physics. For instance, if liquid helium is poured into a vessel it immediately climbs up the internal walls of the vessel and overflows. On the contrary, if an empty cup is partially submerged in liquid helium, the latter quickly fills it to the level of the surrounding liquid.
3. The range of investigations into low temperature has grown and is certain to grow with the progress of physics. Low temperatures are now used in certain studies in nuclear physics, radio-physics, electronics, optics, chemistry and biology. Particularly wide application, however, has been found for them in diverse research into the physics of solids.
Give a short summary of the text
At ordinary temperatures hydrogen and oxygen, and some other potential propellants, for example fluorine, are gases and not until they are in a gaseous state do they undergo chemical reaction in the rocket engine. But in the gaseous form they have such low densities that it would require extremely large tanks to store them in the rocket vehicle. The storage of propellants in the gaseous form is thus completely impractical. It is for this reason that the substances men tioned above are stored as liquids at very low temperatures; they are consequently referred to as cryogenic propellants (from Kryos – ice cold in Greek).
In the liquid form, the densities are much greater than in the gaseous state, and consequently th e propellant tanks can be much smaller and less massive. This advantage is offset, however, by the low temperature required, so that liquid hydrogen, liquid fluorine, and liquid oxygen cannot be stored in the rocket tanks for long periods of time, nor can they be used without special precautions.
Such nonstorable, cryogenic propellants must be loaded into the tanks shortly before the rocket is launched.
Simultaneously compressing and cooling the gases to the required low temperature make the cryogenic liqui ds. They are then stored and transported, with moderate loss, in special vacuum-jacketed tanks. These containers are designed on the same principle as the familiar vacuum- bottles used to store hot or cold liquids in the home.
Here you can see the temperat ures at which a number of cryogenic liquids, of possible use as propellants, liquefy at ordinary atmospheric pressure. These temperatures represent the conventional boiling points of the various liquids. By increasing the pressure in the container the boi ling points can be raised to a certain extent, so that the liquid form can exist at somewhat higher temperatures. It can be seen, however, that the temperatures required to produce and store cryogenic propellants are extremely low by normal standards.
Boiling points of cryogenic propellants
єC єF Hydrogen
In order to avoid the problems associated with cryogenic propellants and to make rockets ready for launching at all times, storable liquid propellants have been developed.