Методика работы со словарем

Е.Н. ЧЕРНЫШОВА

АНГЛИЙСКИЙ ЯЗЫК

МЕТОДИЧЕСКИЕ УКАЗАНИЯ

ДЛЯ ВЫПОЛНЕНИЯ КОНТРОЛЬНЫХ РАБОT

ЭТТМК-ЭНЕРГЕТИКИ

Бузулук 2011

ВВЕДЕНИЕ

Изучаемый вами в нашем институте иностранный язык является обязательным общеобразовательным предметом. Цель обучения иностранному языку в БГТИ на заочном факультете – овладение навыками чтения специальной литературы средней трудности с минимальным использованием словаря.

Студенты заочного факультета изучают иностранный язык на 1, 2 курсах (4 семестра). В конце каждого семестра проводится зачет, в конце четвертого семестра – экзамен. Зачеты по семестрам и экзаменам проводятся в сессию по экзаменационным билетам.

До зачета (экзамена) студенты должны получить отметку о сдаче необходимого материала по семинару, дополнительному чтению и контрольной работе. Содержание этих видов работы излагается ниже в данных методических указаниях и разъясняется преподавателем на установочных занятиях.

Основная форма работы студента-заочника – самостоятельная подготовка без повседневного контроля преподавателя. Заниматься иностранным языком необходимо регулярно с первых же дней учебы. Рабочие записи по урокам желательно вести в общей тетради; сохранив эти записи вы сможете более результативно подготовиться к итоговому экзамену по английскому языку.

Подготовка к семинарскому занятию

В каждом семестре до экзаменационного зачета (экзамена) проводятся групповые семинарские занятия (межсессионные и сессионные).

К семинарскому занятию необходимо подготовить материал уроков 1, 2, 3 соответствующего семестра:

а) изучить грамматический материалсеместра (задание 1 в каждом из трёх уроков);

б) выполнить письменные упражнения (задание 2в каждом из трёх уроков семестра); студенту необходимо записать и само упражнение по-английски и его перевод на русском языке, подчеркивая изучаемые явления иностранного языка;

в) выполнить задания к поурочным текстам (задание 3каждого из уроков семестра);

г) выучить соответствующий семестру лексический минимум;

студенты, не получившие отметку о сдаче материала по семинару, к зачету (экзамену) не допускаются.

Выполнение и оформление контрольных работ

1. Прежде, чем приступить к выполнению контрольной работы, следует изучить теоретический материал и выполнить письменные упражнения к урокам семинара каждого семестра.

2. Контрольные работы выполняются в отдельной тетради. На тетради пишутся фамилия, инициалы и адрес студента, указывается факультет, курс, номер группы и номер контрольной работы.

3. Задания надо выполнять аккуратно и полностью, в той последовательности, как они даны в контрольной работе. Писать синими чернилами четким, понятным почерком. Нумеровать каждое предложение. Контрольные работы, не правильно оформленные или выполненные небрежно или не полностью, возвращаются студенту для переделки.

4. Необходимо оставлять в тетради широкие (около ¼ листа) поля для замечаний рецензента.

5. Английский текст надо писать на левой странице, а перевод – на правой странице на уровне соответствующих английских предложений. условия заданий необходимо выписывать.

6. выполнив контрольную работу, внимательно просмотрите ее сами, проверяя:

а) нет ли пропущенных заданий или отдельных предложений в упражнениях;

б) нет ли орфографических ошибок в английских предложениях и орфографических и пунктуационных ошибок в русском тексте;

в) соответствует ли стиль вашего перевода юридической терминологии.

Только после тщательной самопроверки отправляйте работу на рецензию.

7. Выполненную контрольную работу студент должен выслать в институт для проверки и рецензирования в сроки, установленные учебным планом семестра.

8. Получив проверенную контрольную работу, проанализируйте замечания рецензента и сделайте работу над ошибками:

а) выпишите правильно английские слова, в которых допущены орфографические ошибки;

б) повторите рекомендуемый рецензентом грамматический материал и выполните письменно тренировочные упражнения, если они указаны в рецензии;

в) исходя из контекста и с помощью словаря, установите значения слов, переведенных неверно;

г) напишите правильные варианты перевода предложений; избегайте исправлений в проверочной контрольной работе.

9. Собеседование с преподавателем по контрольной работе проводится устно.На собеседовании нужно представить контрольную работу с

положительной рецензий, письменную работу над ошибками и словарик к английским предложениям и тексту.

На собеседовании проверяются знания всего грамматического материала контрольной работы, особенно тех разделов, в которых были допущены ошибки. Студенты, не получившие зачет по контрольной работе, не допускаются к зачету (экзамену).

Работа с текстами для дополнительного чтения

В каждом семестре студент также сдает материал по дополнительному чтению. Цель работы над текстами по дополнительному чтению - развитие навыков информационного чтения, т.е. чтения ради правильного понимания основных положений текста и положений, их подтверждающих.

При подготовке студент должен отработать чтение и перевод текстов из материала соответствующего семестра. В индивидуальный словарик следует выписывать важные для понимания текста слова им выражения.Прежде всего, необходимо выписывать слова правовой тематики. Записывать слова в словарик следует в их исходной форме, т.е. существительные – в единственном числе, глаголы – в форме инфинитива, прилагательные и наречия – в положительной степени. Для удобства рекомендуется отмечать номера абзацев, к которым относятся выписанные слова, это поможет вам пользоваться своим словарем во время собеседования по тексту с преподавателем.

При контроле готовности по дополнительному чтению студент должен прочитать указанные ему в ходе опроса предложения из текста, перевести их с помощью своего рукописного словарика, ответить на вопросы преподавателя по тексту, найти абзац, в котором излагается та или иная мысль, по возможности изложить основные положения текста на английском языке. Пользоваться письменным переводом во время ответа запрещается.

Методика работы со словарем

Все слова в англо-русском словаре расположены в порядке английского алфавита. Для того чтобы успешно пользоваться словарем и быстро находить слово, надо:

1. Твердо знать английский алфавитв порядке расположения его букв. Для начала можно рекомендовать написать алфавит на вертикальную полоску бумаги и иметь ее перед глазами при работе со словарем.

2. Уметь находить исходную форму слова.При отыскании слова нужно учесть, что словарь дает слова в исходных формах, тогда как в тексте они встречаются большей частью в производных формах. К наиболее употребительным формам относятся:

- Множественное число существительных.

- Степени сравнения прилагательных.

- Третье лицо единственного числа глаголов.

- 2 и 3 формы глаголов (правильных и неправильных).

- Глагольная форма с окончанием –ing.

- Формы, образованные с помощью аффиксации (префиксов и суффиксов).

3. Уметь определять части речи,к которым принадлежит слово. В английском языке по форме слова, в большинстве случаев, нельзя определить, какой частью речи оно является. Так, для слова “work”словарь указывает: 1. n– работа, труд, pl.строительные работы, механизм, мастерские; 2. v – работать, быть в движении, управлять, заставлять работать, решать, обрабатывать.

Различные грамматические значения слов обозначаются посредством служебных слов, т.е. артиклей, предлогов, а также определяются местом, занимаемым словом в предложении, т.е. в зависимости от функции слова в предложении.

Части речи помечаются в словаре арабскими цифрами и условными обозначениями. Наиболее употребительные значения:

n (noun) –существительное

pron (pronoun) –местоимение

a (adjective) –прилагательное

v (verb) –глагол

adv (adverb) –наречие

prep (preposition) –предлог

cj (conjunction) –союз

pl (plural) –множественное число

pp– причастие 2

Полный список сокращений обычно приводится в начале словаря.

4. Правильно выбрать лексический материал.После того, как выяснилось, какой частью речи является искомое слово, необходимо отыскать в словаре нужный русский эквивалент. Задача осложняется тем, что большинство английских слов многозначно. Так, для существительного stateсловарь дает следующие значения: 1) состояние; 2) строение, структура; 3) положение, ранг; 4) государство; 5) штат. Из всех значений, приведенных в словаре для данной части речи, следует выбрать наиболее подходящее, исходя из контекста, а не останавливаться на первом попавшемся значении. В первую очередь следует обратить внимание на техническое значение слова.

Консультации

Студент может обращаться к закрепленному за группой преподавателю со всеми вопросами, возникающими у него в процессе работы над иностранным языком. Еженедельные индивидуальные и групповые консульта-

ции проводятся всеми преподавателями английского языка по расписанию деканата заочного факультета.Если студент не имеет возможности посещать их, то может обратиться к преподавателю письменно и получить консультацию по любым аспектам языка.

Адрес электронной почты преподавателя иностранных языков: chern58@mail.ru

СЕМЕСТР

Задание на семестр

1. Подготовить грамматический и лексический материал к семинару (задание № 1),выполнить письменно упражнения (задание № 2)к каждому из трех уроков, подготовить чтение и перевод текстов к каждому из этих уроков (задание № 3).Выучить лексический минимум.

2. Выполнить письменно контрольную работу № 1.

3. Подготовить чтение и перевод текстов к 1 семестру из пособия по дополнительному чтению.

THE NATURE OF THE ATOM

All the prime movers, natural and man-made, which, humanity has harnessed to

ease its burden of labour and raise its standard of living are, in fact, attempts at

utilizing the energy of the sun: it sustains organic life on earth with its light and heat,it makes the water circulate between the heavens and the sea, it creates the wind, and it has filled for us a vast storehouse of coal and oil, the mineral deposits from old ages of vegetation. What our inventors did when they built power-producing engines was to change one form of energy–such as the heat of burning coal – into another, the mechanical energy of rotating wheels or the light of an electric lamp. They could not create energy from nothing; they could only release it by some chemical process. This means that although the molecules, or combinations of atoms, may break up and form new combinations, the atoms themselves remain intact and unchanged.

There is one source of energy, however, which owes nothing to the heat and

light of the sun; nor can it be harnessed by a chemical process. It is the energy of theatomic nucleus.

The term 'atom', coined by the Greek philosopher Democritus about 2,500

years ago, is rather misleading. It means 'the indivisible', and it is a relic from the

times when people believed that all matter consisted of very small particles which

were Unchangeable and indivisible, and that each element had its own special kind

of particles. Only the medieval alchemists hoped that they could, by some magic,

change the particles of one element into those of another – lead, for instance, into

gold.

Today we know that atoms are neither unchangeable nor indivisable. The story

of research into the nature of the atom has been told many times. It may be sufficient to recall that Marie and Pierre Curie, by their discovery of radium, in 1898, made the whole theory of the indivisible atom crumble, because here was an element which disintegrated and sent out rays, consisting of particles much smaller than the atom. Another discovery, made three years earlier, seemed to point in the same direction: that of the X-rays by Professor Wilhelm Konrad Rontgen at the University of Bavaria. Using a cathode-ray tube, he found that the radiation emanating from it was able to penetrate thin matter like wood and human flesh, but was stopped by thicker objects such as pieces of metal and bones. It was only later that the nature of these mysterious rays was discovered: particles of negative electricity, called electrons, turn into electro-magnetic waves, of the same kind as light but of shorter wave-length and therefore invisible, when they strike a material object such as a metal shield in the cathode-ray tube.

These and other phenomena and discoveries around the turn of the century

were deeply disturbing for the physicists, and they saw that the whole traditional

concept of the structure of matter had to be completely revised More than that: the

borderline between matter and energy seemed to disappear. When, as early as 1905,Albert Einstein published his Special Theory of Relativity, in which he declared that matter could be converted into energy– very little matter into very great energy –there was a storm of protest in the scientific world. But little by little the evidence that he was right accumulated, and within a few years an entirely new picture of the atom emerged from the studies and laboratories of scientists in many countries. From that evidence Lord Rutherford, the New Zealand-born scientist, and his young Danish assistant, Niels Bohr, developed by 1911 their revolutionary theory of what the atom was really like.

That picture of the atom has since been elaborated and filled in with more

details. It is not yet complete; but its essential features are known to be correct otherwise there would be no atomic bombs, which few people would regret, or

nuclear power stations.

Broadly speaking, the atom is a miniature solar system, with a 'sun', the nucleus, and a number of 'planets', the electrons, revolving around it. All the matter of the atom is concentrated in the nucleus: there are protons, particles with a positive electric charge, neutrons, particles without a charge, and some other particles whose hole and nature is still being investigated. The electrons, which have next to no mass and weight, are negatively charged; in fact, they are the carriers of electricity in all bour electric wires and appliances.

Normally there are as many positive protons in the nucleus as there are

electrons revolving around it, so that their charges cancel each other out and the atomas a whole is electrically neutral. But if for some reason an atom loses a proton or an electron or two, its electrical balance is disturbed, it becomes negatively or positively charged and is called an ion.

The atoms of all the elements contain the same kind of particles; what

distinguishes them from each other is merely the number of particles – of protons in the nucleus and of electrons revolving around it. Hydrogen, for instance, being the lightest and simplest element, has only one of each; uranium, the heaviest element occurring in Nature, has 92. So all you have to do to change one element into another is either to knock some protons and a corresponding number of electrons off each atom, or add them; in fact, this process is going on in Nature all the time.

Theoretically, we could change lead into gold, as the alchemists dreamed of doing, by removing three protons and electrons from a few billion lead atoms, which have of each, then we would get gold atoms with 79 protons and electron each. However, the knocking-off process would be much more expensive than the gold we would get.

The neutrons, which are present in the atoms of many elements, are of

particular importance in the utilization of atomic energy. Most elements are mixtures of ordinary atoms and so-called isotopes: the isotope atoms have more, or fewer,neutrons than the ordinary atoms. An isotope differs from the ordinary form of the element only in weight, but chemically it behaves in exactly the same way. Water, for instance, is a mixture of ordinary molecules of hydrogen and oxygen atoms and of 'heavy' ones. The heavy hydrogen atom has an extra neutron in its nucleus.

Uranium, on the other hand, has an jsotope whose nucleus contains fewer neutrons

than the ordinary element. This isotope – atomic weight: 235; atomic weight of

ordinary uranium: 238 – has a very special significance in nuclear physics because it is, like many other heavy-element isotopes, 'unstable'.

What does this mean? Nothing else but the phenomenon which the Curies

discovered in radium. An unstable nucleus is one that is likely to break up into the

nucleus of another element. Professor Otto Hahn found in Berlin in 1938 that when

uranium atoms are bombarded with neutrons they split up in a process which he

called 'fission' (a term used in biology for the way in which some cells divide to form new ones). The 92 protons of the uranium nucleus split up into barium, which has 56,and krypton, a gas with 26 protons. Frederic Joliot-Curie, the son-in-law of Marie Curie, proved some months later that in this fission process some neutrons from the uranium nucleus were liberated; they flew off, and some struck other nuclei, which intern broke up, liberating still more neutrons. Enrico Fermi, an Italian who had gone to America to escape life under fascism, developed the theory of what would happen if a sufficiently large piece of unstable uranium broke up in this way – there would be a’ chain reaction': the free neutrons would be bombarding the nuclei with such intensity that in no time at all the whole lump of uranium would disintegrate. But it would nut just turn quietly into barium and krypton as in Berlin laboratory experiment. There were now two smaller nuclei, no longer held together as before but pushed apart by electric repulsion, and flying off at great speed, with neutrons shooting about in all directions. And such sudden display of energy–for movement is energy – would, according to Einstein's famous Mass-Energy equation, correspond to some loss of mass. If the two parts of a nucleus which has undergone fission could be put together again, their combined mass would be smaller than that of the original nucleus. What has become of the missing bits? They have turned into pure energy – into movement, into heat.

This was the theory that led, within the short space of four years, to the first

atom bombs. On Monday, 6 August 1945, while cheerful crowds in England enjoyed their first holiday after the end of the war in Europe, one such bomb was dropped on the town of Hiroshima in Japan. It killed or injured nearly 200,000 people. Three days later another bomb was dropped on Nagasaki, with 65,000 victims. The centuries of both cities were completely destroyed.

PEACEFUL ATOM

When the world had recovered from the shock of this unimaginable horror,

people everywhere asked the scientists how soon they could apply the immense

power of the fashioned nucleus to peaceful purposes. But this took much longer. It

was considerably easier to use the nuclear chain reaction for destruction than for the production of usable energy for homes and factories–to control it and release it in small doses. Many problems had to be solved; the main one was that of 'braking' the released neutrons efficiently so that the chain reaction would not get out of hand. The first atomic 'pile' or 'reactor', as the apparatus for the utilization of atomic energy is now called, had been Set up by Enrico Fermi on the football ground of the University of Chicago in 1942. It was a somewhat crude assembly, whose main purpose was to get experimental proof for the theory of chain reaction. Fermi scattered rods of uranium through a stack of graphite blocks, which acted as a brake for the neutrons – a 'moderator', to use the technical term. Fermi used natural uranium, which is a mixture of the stable U-238 and the unstable U-235 in a proportion of 140 : 1. Thus there was only slight radioactivity, i. e. breaking-up of nuclei. In order to control it, Fermi inserted some cadmium rods into the pile; this metal absorbs neutrons very readily, and by pushing the rods completely into the pile he could stop the chain reaction altogether.

Fermi's assembly is still the basic blueprint of today's nuclear reactors. Their

main parts are the fuel, the moderator, the control rods, and the cooling system. But the scientists and technicians have since developed a great many different types of reactors – some already in everyday use, others running experimentally in atomic research establishments or being built for special jobs and purposes of all kinds, from producing nuclear explosives for weapons to 'cooking' stable elements' so that they become unstable isotopes for use in medicine, industry, agriculture, and research.

Why do we speak of the atomic age as a new chapter in the history of

civilization, and why have the technologists made such great efforts to utilize the

energy of the split nucleus? For a long time the shadow of a future without sufficient fuel loomed over mankind. Coal has been mined at a steadily increasing pace which set in with the industrial Revolution, and some experts predicted that in Britain, for instance, an acute shortage of cheaply mined coal would set in after 1980. Oil is still to be found in plenty, but consumption has been increasing in leaps and bounds all over the world.

Atomic energy is produced in a different way. It is not generated by the

chemical process of combustion. It is released when nuclei undergo fission, and

although here» too, matter is used up, the amounts are small compared with the

energy produced. A few pounds of uranium 235 can be made to supply a medium sized town with all the electricity it needs during a whole year. True, our reserves of uranium are limited. But there is one reactor type, which in fact produces more

nuclear fuel than it uses! This type has a 'blanket' of thorium, one of the most common elements on earth, which is turned into the artificial radio-active element

plutonium when bombarded by neutrons. And there is good reason to hope that

before long1 we shall be able to produce energy from ordinary sea-water by another nuclear reaction called 'fusion'.

So there is little doubt that mankind's energy problems will be solved in the

near future, if they have not been solved already in principle. All we have to do is

build nuclear reactors and supply them with atomic fuel. But how do we turn it into

usable energy?

The 'classical' solution of this question, although it may soon be regarded as an

old-fashioned one, is to conduct the heat generated by the fission process out of the

reactor, make it boil water, and let the resulting steam drive turbines which, in their

turn, drive electric generators. It is a roundabout way, but it works well, although it is still rather expensive.

Britain's first two nuclear power stations were Calder Hall (opened in 1956)

and Chapel cross (1959), both of the same type. The reactor 'vessel' a giant steel

cylinder, contains a pile of pure graphite, the material from which pencil leads are

made. It has many hundreds of vertical or vertical and horizontal channels; in some of them the fuel – rods of uranium metal in magnesium alloy sheaths – are stacked, in the rest there are the control rods made of boron or cadmium; these can be pushed in and pulled out. A very thick concrete or steel wall around the reactor vessel–-the biological shield' – prevents the escape of radio-activity.

As soon as the control rods are pulled out the chain reaction begins; uranium

nuclei split up under neutron bombardment, and release more neutrons. These

neutrons bounce off the graphite atoms so that they shoot to and fro through the

reactor until they hit and split more uranium nuclei: the graphite acts as the moderator in this process, helping to keep the chain reaction going and preventing the 'capture’ of fast neutrons by the nuclei through slowing them down. The uranium rods get hot(up to 400° C, in Calder Halland Chapelcross), and this heat is removed by the coolant', carbon dioxide gas under pressure. It circulates through the reactor vessel in tubes entering at the bottom at 140° С and leaving it at the top at about 340° С The coolant gas, after leaving the 'core' of the reactor, is conducted to the heat exchangers. They are basically ordinary boilers in which water is turned into steam. The water is contained in steel pipes around which the hot coolant gas is blown. The resulting steam is directed into the turbines which rotate the electric generators. Calder Hall and Chapel cross have eight of them each, generating 180,000 and 140,000 kW respectively of electricity, which is fed into the national grid. If the chain reaction gets too fast and the reactor becomes too hot, the control

rods are lowered into the core automatically, thus slowing down the process; if pushed in completely they will stop it altogether.

Uranium as the fuel, graphite as the moderator, and carbon dioxide gas as the

coolant are only one possible combination. Some nuclear engineers believe that organic substances can be used asmo derators and coolant fluids, others that the fuel should be given the form of a ceramic. A good deal of research work is done with various types of homo geneousre actors, in which fuel, moderator, and coolant circulate as a single, fluid mixture.

Nuclear power is still in roughly the same early phase as steam power was at

the beginning of the nineteenth century, and it may not reach maturity until the end of our own century. By that time, however, we shall not only have fission but also

fusion as a basic energy-producing nuclear process.

The theory of nuclear fusion was discovered in the early 1930's – years before

that of fission – by John Cockeroft at the Cavendish Laboratory, Cambridge, where

he worked under Lord Rutherford. Here they built a simple machine, which looked

more like a couple of stove-pipes than an atom-smashing tool, for shooting

electrically speed-up protons at the nuclei of light elements, such as lithium. The

result was that the lithium nuclei turned into nuclei of helium. This was strange; forhelium is heavier than lithium. Somehow the helium atoms must have been formed not only by splitting but by subsequent accumulation of protons and neutrons. It was only later that it dawned on the physicists that some such process is responsible for the way in which the stars, including our own sun, produce their tremendous energy.

Today we know that in the sun light elements – mainly hydrogen –are turned

into heavier ones, such as helium. This 'thermo-nuclear' process of fusion, as it is

called, takes place at fantastically high temperatures (in the centre of the sun the

temperature is believed to be about 15 million degrees Centrigrade). The heat fuses

the nuclei, which would normally repel each other because they have the same

(positive) electrical charge; heat means violent movement of particles, in other words: energy. Thus the hydrogen nuclei bump into each other and combine to form helium nuclei, with a simultaneous release of energy. As in nuclear fission, some mass is converted into energy in the fusion process, but the sun can keep up its rate of loss of mass – five million tons per second – for some thousands of million years. This process is only possible where light elements are concerned; hydrogen, the lightest of them, has the smallest electrical charge, and therefore the repellent force of its nuclei can be more easily overcome than that of heavier elements. If there was any chance at all of producing nuclear energy from fusion – this was a point about which scientists agreed – it could only be done by using hydrogen: in short, by emulating on earth the process that makes the sun shine.

Again, as in the case of atomic fission, this was first achieved in the form of a

weapon, the hydrogen bomb. Even the testing of this weapon has proved to be highly dangerous because it contaminates the atmosphere all over the world with radioactive 'fall-out' isotopes which can produce cancer of the bone and blood. No one doubts that a nuclear war fought with fission and fusion bombs would mean the suicide of mankind. As these lines are being written many scientists in at least half a dozen countries are busy trying to find a system to tame the energy of the H-bomb for peaceful use, but no decisive 'break-through' has been achieved. It may, however ,come at any moment. In August 1957 British physicists working with their terminus clear device called '2eta' believed they had succeeded, but this turned out to be a mistake. Still, the scientists' efforts towards that goal are all based on the same basic principle, and some time somewhere another Zeta will achieve the 'break-through'. In these experiments the heavy hydrogen isotope deuterium – which has an extra neutron in its nucleus – plays the decisive part. At very high temperatures the protons are detached from the electrons revolving around them, and the neutrons fly off at great speed, thus providing extra energy, i. e. heat, as the protons melt together to form new nuclei. There are many difficult problems to overcome before the thermo-nuclear power station based on this process can become a reality, but that of fuel supply is the least of them: the oceans of the earth are practically inexhaustible source of deuterium, and its extraction from sea water is neither complicated nor expensive. One gallon of sea water may be sufficient to yield as much energy as 100 gallons of petrol, and a bucketful containing one-fifth of a gram of deuterium could keep a five-room house warm for a whole year. The real trouble starts when we attempt to produce the very high temperature required to achieve thermo-nuclear fusion. Up to 1950, the highest temperature ever produced in a laboratory was 30,000° Centigrade. All the Zeta-type assemblies, therefore, are machines designed to reach temperatures of many millions of degrees for heating deuterium gas. This is done electrically. When an electric current is passed through a gas it sets up an electric discharge in it, with a corresponding rise in temperature. A hollow vessel – either ring-shaped or tube-shaped, and usually made of aluminium – is partly encircled by a huge electromagnet which produces the field that heats up the deuterium inside. But if the hot gas touched the walls of the vessel they would melt, and the gas would cool down; therefore, it must be kept in the centre. This is done by another intense magnetic field around the gas, usually by winding an electrically charged cable around the vessel. In this way the gas, which tries to resist that 'pinch effect', is prevented from behaving about like an angry snake as soon as the current is switched on and the temperature rises .Zeta, the British assembly which was originally built at the atomic research establishment, had a ring-shaped form; the 'pyrotfon1, set up at the University of California, was designed as a linear tube with a special 'mirror' effect: the magnetic field was made much stronger at either end so that the 'plasma', as the gas in the machine is usually called, assumed the shape of a sausage – thick in the middle and pinched at the ends. This arrangement had the effect of a magnetic mirror; the particles racing around in the plasma were reflected back from both ends into thecentre, which increased the temperature and also the probability of the particles bumping into each other to achieve fusion. Another American fusion research instrument did away with the magnetic coils, and used a layer of accelerated electrons instead for the production of the necessary magnetic field .When one of the scientists' teams working with these machines achieves genuine fusion – a temperature of up to 500 million degrees Centigrade may be needed to start a thermonuclear process which can maintain itself–the question of how a thermo-nuclear power station could work will become topical. As in conventional power station, coal-fired or atomic, the heat could be used to produce steam for the turbo-generators. But by that time there may be a better and more direct way of turning heat or radio-activity into electricity.

There are several basic systems of doing this. One, called the 'thermionic

converter', uses the principle of the cathode-ray tube in which electrons, particles of negative electricity, are given off by a hot strip of metal, the cathode, in a vacuum. The heat necessary to produce this effect could be that generated in a nuclear reactor; the greater the temperature difference between the cathode, or 'emitter', and the anode, or 'collector', the greater will be the yield of electrons and therefore of electric current. There is, at least theoretically, no reason why a nuclear power station should not be operating on this principle once the technological problems have been solved.

Atomic as well as conventional power stations may be made much more

efficient by the gas-blast system of generating electricity. It is based on the fact that a blast of very hot gas (at least 2,000° Centigrade), which could be produced by a fission or fusion reactor, becomes an electrical conductor and generates current when moving through the poles of a powerful magnet. American and British research laboratories are working on this scheme, but the principal problem is that of finding materials which can withstand such temperatures for any length of time. Another system – which might be better suited for smaller, mobile electricity producing units – is based on a discovery recorded already by the Curies around 1900, but neglected by scientists for nearly half a century. That was the observation that radio-activity could produce electricity directly in certain materials. When, after the Second World War, cheap radio-active sources–isotopes–became available the idea was taken up at last. The first, somewhat crude 'atomic battery', as it was called, was produced in 1954 by a research team in the laboratories of the Radio Corporation of America: a little box containing a thin wafer of the isotope, strontium 90 – one of the dangerous elements in radio-active 'fall-out' after H-bomb tests; it bombarded with its particles a semi-conductor crystal, an adaptation of the transistor. The current generated in the crystal by the radio-active emanation of the strontium was strong enough to produce a buzzing noise in an earphone. Isotopes for direct generation of electricity will be available in growing quantities as the utilization of atomic energy spreads to more and more countries. One of the major problems connected with nuclear power stations is the safe disposal of radio-active waste; burying it, or dumping it into the sea, is not everywhere the best means of getting rid of it. But when devices such as atomic batteries are mass-produced they will require great quantities of radio-active 'waste' products; they must ,of course, be made absolutely safe for everyday use.

How can we tell if we are the target of radio-active emanation? It is invisible

and inaudible, and we cannot feel it – unless and until we have received too much of it and become ill. But there is a vital tool in our nuclear age, the Geiger counter in its manifold forms, which measures radio-activity accurately. Invented by Hans Geiger,a German physicist and one of Lord Rutherford's close collaborators, in the 1920's, it is an ingenious instrument which can make any type of radiation, whether in the form of particles or of electro-magnetic waves, visible and audible.

The Geiger counter consists of a metal cylinder filled with gas at low pressure;

two electrodes – one being the cylinder itself, the other a fine wire stretched along its centre – are maintained at a large potential difference, usually about 1,000– 1,500volts, but no spark is allowed to pass between them. Only when some subatomic particle or unit of electro-magnetic radiation pierces the thin metal of the cylinder and produces ionization (i. e. when the gas atoms become electrically charged), there is a sudden discharge between the electrodes, and the potential drops for the fraction of a second. This can be made either visible on a dial, or audible in a pair of head phones. Frequently, simple counting devices such as telephone counters are attached to the tube to register the number of incoming particles. Geiger counters are being made and adapted for all kinds of purposes–light ones for uranium prospecting; built-in types for atomic power stations and research establishments; counters with warning signals for factory workers who have to handle radio-active matter and whose hands and clothes have to be checked; counters which can test human breath for traces of radon gas, and so on.

Finally, a new source of energy could be created by 'depositing' the heat of a

nuclear explosion deep underground and using it – just as volcanic heat is used in

some parts of the world – for the production of power. It has been estimated that an

atomic blast 3,000 feet underground in a suitable geological formation would produce about 8,000 million kilowatt hours of electrical energy at a cost of 0.04 d. (less than-cent) per kilowatt. In short, the peaceful uses of atomic energy are vast and tempting -but we must stop squandering it on weapons of mass annihilation.

ТЕКСТЫ ДЛЯ ЧТЕНИЯ

SOLAR ENERGY

We know that all the energy mankind has ever used comes from the sun, with

the exception of nuclear energy. If we took all the world's reserves of coal, oil, and

natural gas and burnt them up at the same rate at which we receive the sun's energy,our whole supply would last less than three days. Yet we are only now beginning to

use that vast and almost inexhaustible source of energy in the sky directly.The most primitive device for catching and trapping the heat of the sun is the

gardener's greenhouse. Its modern off-spring is the solar water-heater, usually a coil of pipes placed in a shallow box on the roof of a house, embedded in black concrete black accepts the sun rays more easily, white reflects them) and covered with a glass pane. The water circulating in the pipes is heated by the sun and then pumped into a hot-water tank from which the household takes its supply. In Florida alone, more than50,000 homes get their hot water in this way, and in Israel it has become general practice to install solar water-heaters in new rural houses.

A more complicated but also more efficient device is the heat pump. It is, in

fact, a refrigerator in reverse. It picks up as much heat as it can get either from the

atmosphere, the soil, or from water (a river jar a lake); this amount of heat, which is of course rather small in winter, is made to act on a liquid with a very low boiling point so that it changes into a gas. The gas is then compressed by means of a pump and goes into a condenser coil, where it changes back to a liquid, thus setting its heat free; this can be made to heat the house or to provide hot water. Many heat pumps can be switched to reverse action so that they cool the air in summer. Various types of 'solar houses' have been designed by engineers and architects ,especially in America, where many thousands of them have been built. In these houses, some medium is used to store the heat of the sun and release it gradually as required. Water is a good medium for the purpose, but Glauber's salt (hydrated sodium sulphate) is even more efficient. It melts at a temperature of 90° F., taking in a large amount of heat which it releases again when it turns back into crystals. Twenty tons of the salt in the cellar of the solar house have been found to be sufficient to keep the rooms comfortably warm in winter–with heat collected in the summer!

Another interesting medium is gravel, incorporated in the walls of the house,

which it keeps warm on sunless days; by means of a small ventilator, hot air from a

heat collector on the roof is circulated through the gravel, which releases its

accumulated heat at an even rate.

These efforts at utilizing the heat of the sun show that the engineers are well

aware of the great possibilities of solar heating but also of its limitations. Many

countries, especially in what we call the moderate zones (to say nothing of the cold

regions), do not enjoy enough sunshine to make a solar house worth building, while the tropical zones have no use for extra heat. There, however, cooking by solar energy is becoming more and more important in everyday life.

India has a very limited supply of fuel – its main source for the home is dried

cow dung, which of course would be much better employed in fertilizing the soil. But India has an abundance of sunshine. As early as the 1880's, an Englishman working in India suggested the introduction of a cheap solar cooker, but until fairly recently no really efficient device suitable for mass production had been invented. The Indian National Physical Laboratory and one of the United Nations agencies eventually developed solar cookers, which are being used in creasingly in Indian homes. One type uses a reflecting mirror and a pressure cooker, another has four flat mirrors and an insulated heat-collecting box filled with Glauber's salt crystals, which continue to release heat when the sun has already set.

In the Sudan and East Africa a simple type of solar cooker has become fairly

popular. It consists of a concave aluminum reflector 4,25 feet across, mounted on an upright iron rod; the concentrated rays of the sun fall on the pot or pan placed on a wire-mesh holder which is attached to the reflector.

Another very important device is the solar 'still' for the distillation of fresh

water from salt water, usually working on the principle of a salt-water container

covered by a sloping glass roof; as the heat of the sun evaporates the water, the

vapor condenses in droplets on the glass roof from where they trickle down into a

fresh-water collector. The equally valuable salt is left behind in the saltwater

container. Solar furnaces are still very much in the experimental stage. French scientists are operating them in their research station in the Pyrenees; they are very large – one has a flat reflecting mirror made up of 516 panes and covering an area of 43 feet square and a 31-foot by 33-foot parabolic mirror at a distance of 80 feet. The heat produced by this arrangement is sufficient to melt 130 lb, of iron per hour. The Russians have built an enormous 'helio-boiler', consisting of an 80-foot tower surrounded by twenty-three concentric railway tracks; bogeys move around on these tracks, each carrying a 10-foot by 16-foot reflector to concentrate the sun's rays on to a boiler in the tower. It is claimed that this machine produces enough superheated team for a turbo generator with 1,000 kW output.

The most efficient way of generating electricity from sunlight, however, seemst o be the 'solar battery'. The first of this type was demonstrated in 1954 by a team of

scientists from the American Bell Laboratories. It operated with semi-conductor

crystals similar to those used in transistors either of germanium or of silicon. When

sunlight strikes such a crystal, an electric current is generated. A Bell battery of 40

silicon cells was able to produce a 12-volt current. Since its first demonstration, the

solar battery has been extensively developed and has taken part in one of Man's

greatest adventures – the sending of satellites and rocket vehicles into space. Solar

batteries, as well as the already mentioned atomic batteries, are very suitable for

powering the transmitters in space vehicles because of their long life.

Eventually, solar batteries may be developed to provide all the low-voltage

current needed in a house. Their theoretical top efficiency is 22 per cent,

corresponding to the generation of about 200 watts per square yard of the silicon

surface .French scientists have designed a solar lamp. It is about as big as a small

suitcase; at the top it has a collector panel consisting of a few dozen photo-sensitive silicon cells, and the solar energy which they collect is stored in a small accumulator The underside of the 'suitcase' consists of a fluorescent tube. During day-time the device is put out in the sun, and in the evening it is taken indoors and the lamp switched on. Depending on the time the collector has been exposed to the sun the lamp will then shine for a few hours. Instead of semiconductors the solar battery can also use thermocouples. Here the problem is that of keeping one end of the thermocouple wires cool while the other is heated by the sun – otherwise there will be no current .In the 1950' s, the Solar Energy Committee of the British National Physical Laboratory made a suggestion which could help to provide tropical regions with perpetual energy: the planting of quick-growing forest wood such as eucalyptus, and its continuous combustion in medium-size power stations. A few square miles of eucalyptus forest would yield enough wood to fire the boilers of the power station for ever because the wood would grow as fast as it is used up. Electricity from eucalyptus may not be the most efficient system of turning the energy of the sun into power, but it shows the ingenuity of our scientists in finding new ways and means to provide mankind with more and more energy; and that means: to raise its standard of living. In the old days, the stage of civilization reached by a nation used to be measured in pounds of soap per head a year; today it is the amount of horsepower or kilowatt-hours available to everybody which indicates the degree of civilization.

Now we have the technical means of generating enough energy to raise the

standard of living to a decent level all over the world, and it is our noblest task for the rest of this century to do it.

SOLAR LIGHT BY NIGHT

Most people living in towns consider it a usual thing that streets are lit at night.

But street lights need a power supply (источник энергии) therefore distant areas

with no source of electricity remain in darkness until the sun comes up again.

With new appliances now offered by several British firms, many distant places

could be lit with solar-powered street lights. It may seem strange that the lamps can use the power of the sun which shines by day when the lamps are needed at night, but they work by using energy accumulated during the day from a solar panel. The solar panel produces electricity which charges (заряжать) a battery. When the sun goes down, the battery power is then used for lighting. Each lamp has its own panel so the system can be used for one individual light or a number of them. In the south of Saudi Arabia a motorway tunnel miles from any power supply is lit day and night by solar-powered devices. The solar panels provide power during the day and charge batteries which accumulate enough power to light the tunnel at night. The generation of electricity by batteries is still expensive but the advantage of sun-powered lamps is that they can bring light to areas distant from any other power ;supply.

There is one more advantage of solar power: not only it is unlimited, but also

its use does not pollute the environment. That is why it is very important to develop

devices which make it possible to transform solar power into mechanical or electric

forms of power.

ENERGY

In the language of science energy is the ability to do work. There are various

forms of energy, such as heat, mechanical, electrical, chemical, atomic and so on.

One might also mention the two kinds of mechanical energy–potential and kinetic,

potential energy being the energy of position while kinetic energy is the energy of

motion.

It is well known that one form of energy can be changed into another. A

waterfall may serve as an example. Water falling from its raised position, energy

changes from potential to kinetic energy. The energy of falling water is generally

used to turn the turbines of hydroelectric stations. The turbines in their turn drive the

electric generators, the latter producing electric energy. Thus, the mechanical energy

of falling water is turned into electric energy. The electric energy, in its turn, may be

transformed into any other necessary form.

When an object loses its potential energy, that energy is turned into kinetic

energy. Thus, in the above-mentioned example when water is falling from its raised

position, it certainly loses its potential energy, that energy changing into kinetic

energy.

We have already seen that energy of some kind must be employed to generate

the electric current. Generally speaking, the "sources of energy usually employed to

produce current are either chemical as in the battery, or mechanical, as in the

electromagnetic generator. Chemical sources of current having a limited application,

the great quantities of electric energy generated today come from various forms of

mechanical energy.

The rising standards of modern civilization and growing industrial application of

the electric current result in an increasing need of energy. Every year we need more

and more energy. We need it to do a lot of useful things that are done by electricity.

However, the energy sources of the world are decreasing while the energy needs of

the world are increasing. These needs will continue to grow as more motors and

melted metals are used in industry and more electric current is employed in everyday

life. As a result, it is necessary to find new sources of energy.

The sun is an unlimited source of energy. However, at present, only a little part

of solar energy is being used j directly. How can we employ solar energy directly

to produce useful energy? This is a question which has interested scientists and

inventors for a long time. Lavoisier and other great scientists of the past melted

metals with the help of solar furnaces. Today, solar furnaces illustrate just one of th

numerous ways to harness the sun. Using semiconductors, scientists, for example,

have transformed solar energy into electric energy.

ATOMIC ENERGY

A man trying to see a single atom is like a man trying to see a single drop of

water in the sea while he is flying high above it. He will see the sea made up of a

great many drops of water but he certainly will not be able to see a single drop. By

the way, there are so many atoms in the drop of water that if one could count one

atom a second, day and night, it would take one hundred milliard years. But that is

certainly impossible.

Man has, however, learned the secret of the atom. He has learned to split atoms

in order to get great quantities of energy. At present, coal is one of the most important

fuel and our basic source of energy. It is quite possible that some day coal and other

fuel may be replaced by atomic energy. Atomic energy replacing the present sources

of energy, the latter will find various new applications.

The nuclear reactor is one of the most reliable "furnaces" producing atomic

energy. Being used to produce energy, the reactor produces it in the form of heat. In

other words, atoms splitting in the reactor, heat is developed. Gas, water, melted

metals, and some other liquids circulating through the reactor carry that heat away.

The heat may be carried to pipes of the steam generator containing water. The

resulting steam drives a turbine, the turbine in its turn driving an electric generator.

So we see that a nuclear power-station is like any other power-station but the familiar

coal-burning furnace is replaced by a nuclear one, that is the reactor supplies energy

to the turbines. By the way, a ton of uranium (nuclear fuel) can give us as much

energy as 2.5 to 3 million tons of coal.

The first industrial nuclear power-station in the world was constructed in

Obninsk not far from Moscow in 1954. It is of high capacity and has already been

working for many years. One may mention here that the station in question was put

into operation two years earlier than the British one and three and a half years earlier

than the American nuclear power-stations.

A number of nuclear power-stations have been put into operation since 1954.

The Beloyarskaya nuclear power-station named after academician Kurchatov may

serve as an example of the peaceful use of atomic energy in the USSR.

Soviet scientists and engineers achieved a nuclear superheating of steam directly

in the reactor itself before steam is carried into the turbine. It is certainly an important

contribution to nuclear engineering achieved for the first time in the world.

We might mention here another important achievement, that is, the first nuclear

installation where thermal energy generated in the reactor is transformed directly into

electrical energy.

Speaking of the peaceful use of atomic energy it is also necessary to mention

our nuclear ice-breakers. "Lenin" is the world's first ice-breaker with a nuclear

installation. Its machine installation is of a steam turbine type, the steam being

produced by three reactors and six steam generators. This ice-breaker was followed

by many others.

The importance of atomic energy will grow still more when fast neutron reactors

are used on a large scale. These reactors can produce much more secondary nuclear

fuel than the fuel they consume.

MAGNETISM

In studying the electric current, we observe the following relation between

magnetism and the electric current: on the one hand magnetism is produced by the

current and on the other hand the current is produced from magnetism.

Magnetism is mentioned in the oldest writings of man. Romans, for example,

knew that an object looking like a small dark stone had the property of attracting iron.

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