Translate the sentences. Pay attention to the words in italics. Condensate evaporation pressure tolerance

Condensate evaporation pressure tolerance

Commercial equipment precision surface

Coating emission plasma substrate

Cleaning drying piston sputtering

Chamber division glow discharge solvent

Brand distillation flexible separation

Arc discovery film recovery

Apparatus degassing fermentation purity

Application create extraction pump out

Words to be remembered.

ДОКУМЕНТОВ

УЧЕБНЫХ И НАУЧНО-ИССЛЕДОВАТЕЛЬСКИХ

ПОРЯДОК ОФОРМЛЕНИЯ

Редактор Е.Ф. Сережкина

Св. план, 2007

Подписано в печать 06.07.2007

Формат 60´84 1/16. Бум. офс. № 2. Офс. печ.

Усл. печ. л. 3,7. Уч.-изд. л. 4,12. Т. 300 экз. Заказ 339. Цена свободная

___________________________________________________________

Национальный аэрокосмический университет им. Н.Е. Жуковского

«Харьковский авиационный институт»

61070, Харьков-70, ул. Чкалова, 17

http://www.khai.edu

Издательский центр «ХАИ»

61070, Харьков-70, ул. Чкалова, 17

[email protected]

1. In science vacuum is a space in which there is no matter (substance, gases).

2. A perfect vacuum is unobtainable and the term describes a gas at a very low pressure.

3. The vacuum in this system deteriorates (разряжать).

4. After you wash the windows you can vacuum.

5. His death left a vacuum in her life.

6. Plasma in biology is the same as blood plasma. In physics, plasma is a high temperature gas of charged particles (electrons and ions).

7. The discoverycreated great surprise and interest.

8. The river forms a division between the old and new parts of the city.

9. Equipment is the set of things needed for a particular activity.

10. Piston is moved up and down by means of pressure.

11. He had to drive slowly over the uneven surface of the road.

12. The new discovery had a number of industrial applications.

13. These gas containers will burst at high pressures.

14. The air by the sea is pure and healthy.

15. This machine was built to a tolerance of 0.01 millimeters.

16. “Flexible ” means easily bent without breaking, or easily changed to suit new conditions.

17. Evaporation is the process by which a substance changes from a liquidto avapor.

Self-study Activity

3. Read the introductory text “Vacuum”. Use the dictionary.

Vacuum. A total perfect, vacuum would be a space from which all matter has been removed. This includes solids, liquids and gases (including air). It would be a space that contains “nothing”. Since there is no method or device that can remove all matter from an enclosed space, a perfect vacuum is unknown and has only theoretical meaning. It was once thought that a perfect vacuum might exist in outer space. Now scientist know that the apparently empty space between the stars contain a large mass of gas, which is mostly hydrogen.

An incomplete, or partial vacuum can be created with vacuum pumps. When a very high percentage of gas is removed from a space, it is called a high vacuum and is equal to a very low pressure. Partial vacuums are common. The vacuum bottle has a partial vacuum between double walls. The vacuum keeps liquids near their original temperatures by preventing heat conduction. A partial vacuum must be created in the cylinder of an automobile engine in order to form the air-gas mixture essential to combustion. The vacuum cleaner, vacuum coffee maker, and suction plunger depend upon partial vacuums for their operation. Electric-light bulbs have air removed so that the hot filament will not burn up in the oxygen in the air. The piston movement of a lift pump creates vacuum, allowing water to rise.

Industry has developed many profitable vacuum processes. Liquids under vacuum boil at a temperature lower than the normal boiling temperature. This fact has been useful to food and pharmaceutical manufacturers. Solutions of milk, sugar and fruit and vegetable juices are concentrated under vacuum. This permits the water to boil off at a low temperature and prevents scorching of the product. Vitamins and antibiotics are processed under vacuum to avoid chemical changes that would occur at higher temperatures.

In 1906 evacuated glass tube (вакуумированная стеклянная лампа) was built that could increase the power of an electric signal by many times the original amount. It introduced the age of electronic communicating that gave us radio, television, radar. Vacuum tubes perform vital tasks in the operation of photoelectric cells, electron microscopes, and hundreds of other types of electronic equipment.

The scientists’ interest on vacuum is constant. The case is that in a very high vacuum almost all gas molecules have been removed from an enclosed space. A particle passing through it moves a relatively long distance before colliding with another particle. A physicist can control and study a single particle without interference. He uses electrical and magnetic fields to guide a stream of electrons or neutrons to a particular target. The cyclotrons in nuclear laboratories are simply machines for speeding particles around a carefully planned route in a vacuum. Such studies provide results that help scientists to solve the mystery of molecular structure. The history of progress in the study of vacuum is also the history of vacuum-pump design.

4. Read text A carefully paying attention to the words in bold type.

A. History of PVD Coatings

The term physical vapor deposition, PVD seems to have been originally termed by the authors C.F. Powel, J.H. Oxley in their 1966 book “Vapor Deposition.” However, PVD processes were invented much earlier. The vapor source may be from a solid or liquid surface (physical vapor deposition – PVD) or from chemical vapor deposition – CVD. The history of PVD is closely associated with the development of vacuum technology, the discovery of electricity and magnetism and the understanding of gaseous chemistry.

The first piston type vacuum pump was invented by Otto von Guericke to pump water out of mines as far back as 1640. He called the pumps “air pumps”. But the first person to use the vacuum pump to be able to form a glow discharge (plasma) in a vacuum tube was Michael Faraday. In 1838 he used brass electrodes and a vacuum of approximately
2 Torr. Torr [(named after Evangelista Torr (icelli)] is a unit of pressure, being the pressure necessary to support a column of mercury, one millimeter high at 0 °C and standard gravity (сила тяжести) equal to 1333.2 microbars. (Turn to page 106 for further information).

In 1852 W.R. Grove was the first to study what became known as “sputtering” although others had observed the effect while studying glow discharges. Grove used a tip of wire as the coating source and sputtered a deposit onto a highly polished silver surface held close to the wire at a pressure of about O.5 Torr. He noted a coating on the silver surface when it was made the anode and the wire the cathode of an electrical circuit.

In 1858 Professor A.W. Wright of Yale University published a paper in the American Journal of Science and Arts on the use of an “electrical deposition apparatus ” that he used to create mirrors. This form of deposition may have been arc evaporation based, rather than sputtering. T. Edison’s patent application for vacuum coating equipment differed from A. Wright’s. Edison successfully argued that his invention was a continuous (непрерывная) arc whereas Wright’s process was pulsed (импульсная) arc. Edison could therefore be said to be the first person to make commercial (промышленный, технический) use of sputtering.

The term CVD chemical vapor deposition was introduced later.

Now everything is coated with CVD, and masking is almost impossible. It is known that vacuum coatings offer more flexibility. It has a large potential for growth particularly in decorative business. Much depends on how fast designers and engineers will be educated in the field; and on pushing down prices.

All PVD processes can be separated into three stages: 1) Emission from a vapor source; 2) Vapor transport in a vacuum; 3) Condensation on the substrate.

Comprehension Check – 1

Дата добавления: 2014-12-26