Home Random Page


CATEGORIES:

BiologyChemistryConstructionCultureEcologyEconomyElectronicsFinanceGeographyHistoryInformaticsLawMathematicsMechanicsMedicineOtherPedagogyPhilosophyPhysicsPolicyPsychologySociologySportTourism






Chapter XXIX

 

Chemical (источники) of an emf which (используются) for discharge only, thereby (превращая) chemical energy into electrical energy, (называются) primary cells. A simple primary cell consists of a containing jar (наполненный) with a solution of sulphuric acid as the

(электролит), a zinc plate and a cooper plate as ( электроды) . The most widely used primary cell of non-polarizing type is the Leclanche cell. It comprises a zinc and carbon electrode in a solution of ammonium chloride, often called sal ammoniac. The carbon (positive) electrode is packed in a (смесь) of manganese dioxide and carbon as a (деполяризатор).Also there are the storage cells. The distinction between an electric storage cell ( also called secondary cell or accumulator ) and a primary cell is that a storage cell after being discharged can be brought back to a full state of ( зарядка) by passing an ( электрический ток) through it. A lead storage cell consists of several negative and positive plates immersed in an electrolyte of (серная кислота) and (дистиллированная) water with a specific gravity of 1.08 to 1.21. The plates may be either of the Plante (formed) type or the Faure (pasted) type. There are two distinct types of (щелоч-ной) cells: the nickel-iron type and the nickel-cadmium type (the Russian type designations are ЖН и КН).

 

J. Revise the above texts and answer the following questions to them.

1. What is electrolysis?

2. What is the essence of Faraday’s first and second laws?

3. What is the form of a storage cell?

4. What does a lead storage cell consists of?

5. What is the construction of a simple primary cell?

6. What types of alkaline cells do you know?

K. Translate the following text from Russian into English, using new words.

 

 

K. Give the annotation of this text in Russian, learn all new words to improve your

vocabulary.

 

Incandescent (filament) lamps

 

Incandescent lamp was invented by Lodygin from Russia who demonstrated his invention in 1873, well before Edison. It consists of a filament which is highly refractory conductor mounted in a glass bulb. The filament is heated by the passage of an electric current through it to such a high temperature that it becomes incandescent and emits light.

To prevent rapid burning of the filament, the air is exhausted from the glass bulb, to form

a partial vacuum, hence the name vacuum lamp. Now incandescent lamps have filaments which are made of refractory metals such as osmium or tungsten. Heated to 2200 * C in vacuum lamps, the tungsten filament emits a brighter light, and consumes less energy. Such lamps have a very low luminous efficiency, only about 4 or 5 per cent of the electric energy consumed being converted to light, while the remainder is lost as heat.

Another group of lamps includes gaseous discharge lamps now widely used for decorative purposes, advertising, signs. These are mercury vapour, sodium vapour and neon lamps.

Another class of lamps embraces fluorescent lamps. It is a quartz tube filled with low-pressure mercury vapours. The inside of the tube is coated with a fluorescent powder, or phosphor, which converts the ultraviolet radiation of mercury discharge into visible light.



 

 

L. Make up your own reports on electrolysis, lamps, conductors, Joule’s law, Lodygin and

Edison. Get ready to discuss them with your group-mates.

Chapter XXIX

On the steamer that took them up the Western River Walter read incessantly, but at meal-times he endeavoured to make some kind of conversation. He talked to her as though she were a stranger with whom he happened to be making the journey, of indifferent things, from politeness, Kitty imagined, or because so he could render more marked the gulf that separated them.

In a flash of insight she had told Charlie that Walter had sent her to him with the threat of divorce as the alternative to her accompanying him to the stricken city in order that she might see for herself how indifferent, cowardly and selfish he was. It was true. It was a trick which accorded very well with his sardonic humour. He knew exactly what would happen and he had given her amah necessary instructions before her return. She had caught in his eyes a disdain which seemed to include her lover as well as herself. He said to himself, perhaps, that if he had been in Townsend's place nothing in the world would have hindered him from making any sacrifice to gratify her smallest whim. She knew that was true also. But then, when her eyes were opened, how could he make her do something which was so dangerous, and which he must know frightened her so terribly? At first she thought he was only playing with her, and till they actually started - no, later, till they left the river and took to the chairs for the journey across-country, she thought he would give that little laugh of his and tell her that she need not come. She had no inkling what was in his mind. He could not really desire her death. He had loved her so desperately. She knew what love was now and she remembered a thousand signs of his adoration. For him really, in the French phrase, she did make fine weather and foul. It was impossible that he did not love her still. Did you cease to love a person because you had been treated cruelly? She had not made him suffer as Charlie had made her suffer and yet, if Charlie made a sign, notwithstanding everything, even though she knew him now, she would abandon all the world had to offer and fly to his arms. Even though he had sacrificed her and cared nothing for her, even though he was callous and unkind, she loved him.

At first she thought that she had only to bide her time, and sooner or later Walter would forgive her. She had been too confident of her power over him to believe that it was gone for ever. Many waters could not quench love. He was weak if he loved her, and felt that love her he must. But now she was not quite sure. When in the evening he sat reading in the straight-backed black-wood chair of the inn with the light of a hurricane lamp on his face she was able to watch him at her ease. She lay on the pallet on which her bed presently would be set and she was in shadow. Those straight, regular features of his made his face look very severe. You could hardly believe that it was possible for them on occasion to be changed by so sweet a smile. He was able to read as calmly as though she were a thousand miles away; she saw him turn the pages and she saw his eyes move regularly as they travelled from line to line. He was not thinking of her. And when, the table being set and dinner brought in, he put aside his book and gave her a glance (not knowing how the light on his face threw into distinctness his expression), she was startled to see in his eyes a look of physical distaste. Yes, it startled her. Was it possible that his love had left him entirely? Was it possible that he really designed her death? It was absurd. That would be the act of a madman. It was odd, the little shiver that ran through her as the thought occurred to her that perhaps Walter was not quite sane.

 


Date: 2014-12-28; view: 786


<== previous page | next page ==>
PRIMARY CELLS. | Chapter XXX
doclecture.net - lectures - 2014-2024 year. Copyright infringement or personal data (0.006 sec.)