Архитектура Аудит Военная наука Иностранные языки Медицина Металлургия Метрология
Образование Политология Производство Психология Стандартизация Технологии


Read and translate the international words.



Aero´plankton n, bac´terium/bac´teria (pl) n, spore n, ´urbanize v, com´ponent n, ´carcino´genic a, ef´fective a, ´sanitary a, hy´gienic a, ´modernize v, ´aerosol n, metallurgical a.

3. Learn all the meanings of the term carbohydrates and choose the appropriate translation in the sentences below.

carbohydrate(s) - хим.       углевод
  энерг . углеводороды
  мед.       углеводы; углеводный
  экол .     гидроокись углерода; карбогидрат

1. Carbohydrate engineering deals with selective purposive changes of carbohydrates or oligosaccharide bonds in a glyco-protein molecule.

2. Carbohydrate raw materials form the basis of modern power generation sector.

3. Sodium lactate (E270 /E325) belongs to the group of organic acids produced by fermentation of renewable carbohydrate raw materials. 4. Carbohydrate metabolism is vitally important for normal functioning of all higher animals. 5. The automobile exhaust gases contain a number of carbohydrates, including ethylene, methane, toluene and others. 6. Liquid and gaseous fossil fuels are mainly carbohydrates like natural gas and oil.

Study the following chart. Pay special attention to the Grammar forms of the verbs in bold.

1. If the depletion of the Earth’s resources goes on uncontrolled the world environment will change irreversibly. 2. They will install this refinery provided it is effective enough. 3. If we used it in time, we shouldn’t exceed MAC standards. 4. He would have done this work, if he had received these agents in time. 5. Were the sulphur melted and allowed to cool, it would form long monoclinic needles. 6. Had they been informed before, they should have prevented that emergency.

Translate these sentences and pay your attention to the Conditionals.

    1. Phosphoric acid behaves in certain respects as if it were a mixture of three different degrees of activity. 2. If no catalyst were employed in cracking, the process would be called thermal cracking. 3. If the gas were colourless, we shouldn’t notice its formation. 4. If two liquids had been mutually insoluble, neither one would have lowered the vapour pressure of the other. 5. If there was no order in the way atoms of difference elements to form molecules, it would be necessary to memorize one by one the formula of thousands of substances. 6. Were water allowed to run back into generator an explosion might result. 7. Had we been told earlier, we should have agreed, but now we can’t.

 


5. Match the word-combinations in A with the corresponding phrases in B:

A B
1. raw materials a. канцерогенные вещества
2. blast furnace gases b. выхлопные газы
3. paper manufacturing enterprises c. тонкодисперсная пыль
4. synthetic fibers d. газы доменной печи
5. thermal electric plants e. соединения, содержащие серу
6. low-grade coals f. синтетические волокна
7. sulphur-containing compounds g. низкосортные угли
8. finely dispersed dust h. предприятия, производящие бумагу
9. exhaust gases/fumes i. сырьё
10. carcinogenic substances j. теплоэлектростанция

Read and translate the following word combinations:

pollute the atmosphere with/by, grow in proportion to the population, be broken down into several groups, sulphur-containing compounds, is accompanied by the emission of, is not a threat to man, deadly poisonous, convenient means of transport

 

Read the text and express the main idea of every passage in one phrase.

SOURSES AND COMPOSITION OF ATMOSPHERIC

POLLUTANTS

Scientists distinguish between natural and artificial sources of atmospheric pollution.

Natural pollution of the atmosphere occurs when volcanoes erupt, rock is weathered, dust storms take place, forests fire and sea salt is washed ashore. The atmosphere always contains aeroplankton (bacteria, including those causing disease), fungi spores, plant pollen, etc.

Artificial pollution of the atmosphere is characteristic mostly of cities and industrial centers. Cities and suburbs contain numerous industrial enterprises, automobiles and heating system which pollute the atmosphere and negatively influence the local climate. It has been established that air pollution in urban areas grows in proportion to the population. Industry pollutes the atmosphere by emissions of harmful gases and industrial dust. Thermal electric plants, metallurgical and chemical plants, oil refineries, cement and other works are sources of air pollution.

For a long time the problem of air pollution in the cities was chiefly related to coal-burning in heating system which emitted smoke, ash and sulphurous gas (SO2). Large amounts of dust were emitted into the atmosphere by thermal electric plants using low-grade coals that yield large quantities of soot and a high percentage of sulphur-containing compounds (approx. 400 tons of sulphurous gas every day).

The chemical composition of emissions into the atmosphere depends on the kind of fuel, of raw materials, technology, etc. For example, blast furnace gas contains poisonous carbon monoxide, while the smoke of aluminium factories pollutes the atmosphere with fluoride compounds. Paper manufacturing enterprises emit soot, sulphurous anhydride, hydrogen sulfide and mercaptan into the air. The production of synthetic fibres (nylon, for example) is accompanied by the emission of toxic carbon disulfide (CS2) and hydrogen sulfide.

Today automobiles are the primary sources of atmospheric pollution. The number of automobiles is rapidly increasing in all industrial countries. There are more than 400 million motor vehicles in the world today. It is estimated that one car burns up the amount of fresh air needed for 100 adults to breathe. At the same time it emits the same amount of fumes into the atmosphere. Besides, urban runoff of pollutants washes off impervious surfaces (roads, parking lots, and rooftops) during rain storms.

It was stated that the automobile exhaust gas is a complex mixture of many components. But their diversity may be broken down into several groups.

The first group includes non-toxic substances: nitrogen, oxygen, hydrogen and water vapour. Carbon dioxide (C02) may also be included in this group as it is not a threat to man.

The second group includes carbon monoxide (CO), a very toxic gas introduced in large quantities (up to 12 per cent).

The third group consists of the nitrogen monoxide (NO) and dioxide (NO2), also very toxic.

The fourth, the most numerous group of substances consists of the hydrocarbons, including ethylene, acetylene, methane, propane, toluene and others.

The fifth group is made up of the aldehydes, mostly the very toxic formaldehyde (formalin).

Finally, the sixth group is soot emitted by Diesel engines. It has the capacity to adsorb the carcinogenic substances contained in exhaust fumes.

City air is polluted not only with exhaust fumes but also the products of their oxidization, often much more toxic than the initial substance. One of them is epoxide (ethane oxide), which is deadly poisonous in large concentrations.

8. Answer the questions to the text:

1. What sources of atmospheric pollution do ecologists distinguish?

2. What kind of pollution is typical for urban areas and industrial centers?

3. What does the chemical composition of emissions depend on?

4. What kind of manufacturing enterprises pose the greatest danger to ecological situation?

5. Why are exhausts considered to be a complex mixture?

6. Is soot emitted by diesel engines dangerous for health?

7. Why are the oxidization products of exhausts greatly concerned about by both medical workers and environmental chemists?




9. Generalize each group of the words by one term or notion:

1) bacteria, fungi spores, microbes;

2) formaldehyde, nitrogen monoxide, carbon disulfide;

3) chemical factories, oil refineries, automobiles;

4)  exhaust fumes, smoke, harmful gases, industrial dust;

5) methane, propane, toluene.

10. a) Read, understand and title the text.

b) Comment the figures given in the text.

c) Find the phrases explaining the mechanism of “greenhouse effect”.

d) Explain why carbon dioxide is extremely important for life.

Since most of human activities has been closely linked with industries the amount of carbon dioxide in the atmosphere of the Earth has increased from 290 parts per million to slightly more than 330 parts per million. Perhaps a fourth of the total increase has come within the past decades. By the year 2020, if present trends continue, the amount of carbon dioxide in the atmosphere could approach twice the current value. Until recently the increase was commonly attributed to the burning of fossil fuels.

“The Earth's surface and the clouds absorb visible and invisible radiation from the sun and re-emit much of the energy as infrared back to atmosphere. Certain substances in the atmosphere, chiefly cloud droplets and water vapor, but also carbon dioxide, methane, nitrous oxide, sulfur hexafluoride, and chlorofluorocarbons, absorb this infrared, and re-radiate it in all directions including back to the Earth”.

Carbon dioxide is only a trace gas in the atmosphere of the Earth as it presents at a concentration of about 0.03 per cent by volume. Nevertheless, it plays possibly a critical role in controlling the climate of the Earth because it absorbs radiant energy at infrared wavelengths. Heat trapped in this way has a large potential for altering the world climate substantially. Thus, the greenhouse effect keeps the atmosphere and surface much warmer than if the infrared absorbers were absent from the atmosphere.

And quite apart from possible effects on the climate, carbon dioxide in the atmosphere also plays a critical part as the source of carbon that is fixed in green plants by photosynthesis and therefore provides the basis for all plant and animal life.

Thus, mankind therefore faces a historic dilemma. The human activities that are increasing the carbon dioxide content of the atmosphere promise to bring a general warming of the climate over the next several decades. Although one can be certain neither of the way and rate the climate will change nor of the precise mechanisms that will be involved, however, the results of a steadily rising amount of carbon dioxide in the atmosphere will almost certainly be destabilizing.

/Earth as an infrared emitter /http://en.wikipedia.org/







Последнее изменение этой страницы: 2019-04-01; Просмотров: 229; Нарушение авторского права страницы


lektsia.com 2007 - 2022 год. Все материалы представленные на сайте исключительно с целью ознакомления читателями и не преследуют коммерческих целей или нарушение авторских прав! (0.015 с.) Главная | Обратная связь