Complete the sentences with the words below. Explain the function of each device
Module 11
Lesson 4
In what fields are superconductors most widely used?
1________________ 2___________________________ 3__________________________
Work in pairs or small groups. Read the text and brainstorm some ideas for possible uses of superconductivity in the near future
Applications of superconductivity
What's so good about superconductivity? Yes, you can make little bits of ceramics float if you make them really cold, but what else can you do? Imagine if we could make a material that was superconducting at room temperature. Our computers would work faster because they'd allow electric currents to flow more easily. We could make powerful electromagnets that turned electricity into magnetism without wasting anything like as much energy. That would mean electric appliances in our homes and offices would waste much less power. We could also make "Maglev" (magnetic levitation) trains that would float on rails using linear motors and get us around with a fraction of the power used by current locomotives. Engineers are already trying to use superconductors in all these ways, but if they could find a really high-temperature superconductor (one that worked at about 0–20°C (32–68°F or 273–293K), their job would be an awful lot easier!
Called superconductivity this discovery remained without practical applications for decades.
But nowadays superconductors are already used in many fields: electricity, medical applications, electronics and even trains. They are used in laboratories, especially in particle accelerators, in astrophysics in ultrasensitive magnetic detectors called SQUIDs and in superconducting coils to produce very strong magnetic fields.
However, they need to be cooled to very low temperatures, and this fact restricts their use in our everyday life. But new applications are already operational in laboratories and will be able to spread to our cities and our homes if the cooling process becomes less expensive or, better, if we discover superconducting materials that do not require any cooling. If this happens, we can expect an actual revolution in energies and environment on the one side and transportation and computer science on the other.
When you have finished, compare your ideas with your group, or the rest of the class.
Which were the most popular ideas? Have a group vote on the best idea of all.
Find someone who…
|
|
|
1 generated the most ideas
2 suggested the most practical ideas
3 had the most ambitious ideas
4 resisted new ideas
5 is good at improvising and coming up with new ideas
55. Work in pairs. Student A: Read the facts and figures about applications of superconductivity.
Student B: Read your version of the facts and figures on page 25
Ask your partner questions to complete the missing information in your text.
Student A:
1 One of the biggest successes in the recent past is the production of a flexible yttrium-barium-copper-oxide tape, created in ________(when?).
2 Electricity has become an essential energy source in our modern lives. However, today’s power cables can only carry limited currents _________(why?). A network of ________(what?) would solve this problem because 1000 times more electric current can flow through them: smaller cables with more currents.
3 Superconductors can also be used to make a device known as superconducting quantum interference device (SQUID). This is incredibly sensitive to small magnetic fields so that it can detect the magnetic fields from the heart (10 -10) and even the brain (10-13 Tesla). For comparison, the Earth’s magnetic field is about 10 -4 Tesla. As a result, SQUIDs are used in medical diagnostics on the brain.
4 A use of large and powerful superconducting electromagnets is in a possible future energy source known as nuclear fusion. An international fusion energy project, known as the International Thermonuclear Experimental Reactor (ITER) is currently being built in the south of France that will use large superconducting magnets and is due for completion in 2017.
Complete the sentences with the words below. Explain the function of each device
The magnetic resonance imaging current limiters squid magnetometers filter(s)
1__________ ________enable very accurate measurement of magnetic field.
2 Superconducting circuits can be built so as to efficiently protect an electrical plant from supply accidents (high voltage, short-circuit). These_______ _________react very quickly, guarantee an optimum protection of the plant and automatically reset when the accident is over.
|
|
|
3 _________ ________ __________ devices that have become mainstays of modern diagnostic medicine have been the best-known important practical application of the advances in superconductivity made in the second half of the 20th century.
4 A _________ is an electronic circuit that selects some frequencies and blocks all the others. This kind of circuit is used in radio sets, for instance, to select the radio station we want to listen to. _________made of superconducting materials are more efficient than regular _______. They are used in relay antennas for cell phones and enable to pick up a signal at further distances from the antenna, hence increasing the range of the antenna.
These ___________could also be used in telecommunication satellites.
57. Use the prompts to complete the sentences
1 Floating Maglev trains would be much more practical if superconductors / work/ high/ temperature.
2 In theory, high-temperature superconductors could improve all existing electronics.
By replacing copper with superconductors / energy/waste/useless/ heat/
3 Accelerators guide particles and accelerate them using /magnetic /field/ strong
4 Materials exhibiting superconductivity basically allow for the passing of electrical current through them without opposing /resistance/ electrons/flow
5 Until the discovery of high –temperature superconductors, the use of superconductors required … (rare and expensive) or … (very explosive)
6 If superconductors with critical temperature above room temperature are ever found, technology/drastically/alter.
58. Watch the video IFW-Dresden Superconducting Maglev Train Models and answer the questions
Useful notes
passionate fan – страстный поклонник
friction - трение
evaporate - испарять(ся)
humidity – влажность
shim - тонкая прокладка
conventional material – обычный материал
transition temperature – температура, при которой материал становится сверхпроводящим
|
|
|
magnetic flux – магнитный поток, магнитные силовые линии
maintain – поддерживать, сохранять
cease – прекращать, переставать
1 Does the train use any motor?
2 The train really steams. What evaporates inside the model steam engine?
3 What is the core of this magnetic levitation train?
4 What is the rail made of?
5 What determines the distance between the rail and train?
6 What happens with the superconducting material when the liquid nitrogen is evaporated?
7 Can the distance between the rail and locomotive be varied?
8 What is this impressive experiment designed for?
59. Watch the video again* and choose the correct alternative
1 The superconductor is brought into a certain distance of a few millimeters above the magnetic rail and is cooled down in this position using liquid nitrogen/ using liquid helium
2 To get the superconducting train in motion one has to give it an initial impulse by hand. Due to the friction/ the lack of friction the steam engine goes round and round until the liquid nitrogen is evaporated and the material warms up.
3 The train really steams but it’s not water evaporates inside the model steam engine but liquid nitrogen so cold that humidity condenses on it /that the temperature drops to zero.
4 Reaching the specific transition temperature the superconductor traps the magnetic flux of the outer field. Now we can remove the shim of a certain thickness which determines the distance/
which protects the material from the magnetic flux.
5 The superconductor is fixed at this distance and can only move along the magnetic rail even when turning upside down but the effect lasts only aslongasthe superconducting state in thematerial appears/ the superconducting state in the material is maintained.
6 Above the so called transition temperature superconductors are no longer affected by magneticfields and a locomotive goes round and round /drops back to the rail due to the effects of gravity.
|
|
|
7Then it’s time to refill the liquid in order to recool the superconductor below zero/ its transition temperature.
8 The train looks like a toy for playful physicists but it could soon become reality for technicians/it is designed to test superconducting materials.
* If necessary
Дата добавления: 2018-05-13; просмотров: 498; Мы поможем в написании вашей работы! |
Мы поможем в написании ваших работ!