Text e. Surface treatments of light alloys

Other than ferrous materials, the most widely used metals in race engines are aluminium and titanium. Magnesium comes some way down the pecking order (неофициальная иерархия), this having something to do with rules that deem magnesium not good for racing, although production engine manufacturers are very keen on it. The most common surface treatments applied to aluminium alloys are the anodising processes of which there is a great variety. Many of these are simply to improve the surface appearance of the material, and such thin-oxide films can be successfully dyed to produce some quite attractive coloured parts. Where race engines are used over long periods between rebuilds, thin anodised films can offer a very useful degree of corrosion resistance compared to untreated parts.

Thicker anodised surface treatments, called hard anodising, are rarely coloured but are more functional in bringing real improvements to the surface which go beyond corrosion resistance and improved aesthetics. The thicker oxidised layer allows aluminium parts to be used in more aggressive surface contact applications. By replacing a soft aluminium surface with one of aluminium oxide, which is much harder, problems such as cold welding (сварка) of aluminium to parts that are in contact with it can be eliminated (исключать, устранять). One common use of the process in race engines is on piston ring grooves (канавка поршневого кольца) to prevent ‘ring sticking’ (залипание, залегание компрессионного кольца, пригорание поршневых колец). Hard anodising processes can cause a significant decrease in endurance limit for aluminium alloys, although the percentage decrease depends both on the particular grade of aluminium and the hard anodising method being used. The porous nature of the thick anodised film allows it to be further treated with polymer materials such as PTFE (политетрафторэтилен, т.е. тефлон), giving a low coefficient of friction.

Anodising processes are also applicable to titanium, with thin oxides providing a degree of corrosion resistance and some attractive 'interference colour’ effects without the need to resort to dyed films. The anodising of titanium can help to prevent the serious problem of galling (задир, наволакивание металла, истирание), where surface seizure can result in sliding contacts under very low speeds and pressures. It finds particular use on special-purpose titanium studs (винт, болт, шпилька, штырь, цапфа) and threaded (thread – резьба) components for this reason.

Source: http://www.ret-monitor.com/articles/pdf/surface-treatments.pdf pages 47-48 Symbols: 2 133

ПР

Digital Signal Processing 1 (dsp)

Digital signal processing is one of the most powerful technologies that shape science and engineering in the twenty-first century. Revolutionary changes have already been made in a many fields: communications, medicine, radar and sonar², music reproduction, oil prospecting, etc. Each of these areas has developed a deep DSP technology, with its own algorithms, mathematics³, and specialized techniques⁴. This combination of breadth and depth makes it impossible for any one individual to master all of the DSP technology that has been developed.

Digital Signal Processing is distinguished from other areas in computer science by the unique type of data it uses: signals. In most cases, these signals originate as sensory data from the real world: seismic vibrations, visual images, sound waves, etc. DSP is the mathematics, the algorithms, and the techniques used to manipulate these signals after they have been converted into a digital form.

The roots of DSP are in the 1960s and 1970s when digital computers first became available. Computers were expensive at that time, and DSP was limited to only a few applications. The first efforts were made in four key areas:

1. radar and sonar, where national security was at risk;

2. oil exploration, where large amounts of money could be made;

3. space exploration, where the data are irreplaceable⁵;

4. and medical imaging, where lives could be saved.

The personal computer revolution of the 1980s and 1990s caused new applications of DSP. Besides being used in military and government areas, DSP was suddenly offered by the commercial marketplace. Anyone who thought they could make money in the rapidly expanding field became suddenly a DSP vendor⁶. DSP reached the public in such products as: mobile telephones, compact disc players, and electronic voice mail.

Today, DSP is a basic skill⁷ needed by scientists and engineers in many fields. As an analogy, DSP can be compared to a previous technological revolution: electronics. In the field of electrical engineering nearly every scientist and engineer has some skill in basic circuit design. Without it, they would be lost in the technological world. DSP has the same future. (1862p.s)

Vocabulary

1. Digital Signal Processing – цифровая обработка сигнала

2. Sonar – гидролокация

3. mathematics – зд. математические символы

4. techniques – методы

5. irreplaceable – незаменимые

6. a vendor – продавец, торговец

7. skill – умение

I. Answer the question:

What bind of data does DSP manipulate?

1. Radiation coming from space.

2. Data used in military and government spheres.

3. Signals which originate in nature.

4. Sensory images produced by computers.

II. Decide which statement matches the text:

1. DSP is limited to only a few applications at present.

2. DSP does not have any commercial application.

3. DSP is one of the leading technologies of the nearest future.

4. DSP can never reach public.

III. Decide which statement does not match the text:

1. Any person is capable of gaining command of DSP.

2. DSP has altered a lot of spheres of science and technology.

3. DSP is vital in the matters of national defense.

4. DSP has been widely used in information technology since the 1980s.

IV. Decide which definitions match the following terms:

1. oil prospecting a) symbols used to write formulas

2. digital signal processing b) geological search of oil and gas fields

3. circuit design c) an area of electronics dealing with

production of integral circuits

4. mathematics d) turning sensory signals into a digital form

V. Fill in the gaps with the words from the list below:

skill, techniques, irreplaceable, mathematics, DSP, a vendor

1. The new device has proved __________________in our research programme.

2. We use a set of specialized __________________in our research.

3. Basie computer literacy is probably the main_________________ required in this activity.

4. _____________________ is a universal language used by scientists and engineers in the rapidly developing area of digitization.

5. _____________________ has originated as purely scientific technology, but it is widely offered by commercial market nowadays.

6. He has made his way up to the top manager of a well- known retail company, but he started his career as a street ___________________.