REFRIGERATORS are the epitome of clunky technology: solid, reliable and just a little bit dull. They have not changed much over the past century, but then they have not needed to. They are based on a robust and effective idea--draw heat from the thing you want to cool by evaporating a liquid next to it, and then dump that heat by pumping the vapour elsewhere and condensing it. This method of pumping heat from one place to another served mankind well when refrigerators' main jobs were preserving food and, as air conditioners, cooling buildings. Today's high-tech world, however, demands high-tech refrigeration. Heat pumps are no longer up to the job. The search is on for something to replace them.
One set of candidates are known as paraelectric materials. These act like batteries when they undergo a temperature change: attach electrodes to them and they generate a current. This effect is used in infra-red cameras. An array of tiny pieces of paraelectric material can sense the heat radiated by, for example, a person, and the pattern of the array's electrical outputs can then be used to construct an image. But until recently no one had bothered much with the inverse of this process. That inverse exists, however. Apply an appropriate current to a paraelectric material and it will cool down.
Someone who is looking at this inverse effect is Alex Mischenko, of Cambridge University. Using commercially available paraelectric film, he and his colleagues have generated temperature drops five times bigger than any previously recorded. That may be enough to change the phenomenon from a laboratory curiosity to something with commercial applications.
As to what those applications might be, Dr Mischenko is still a little hazy. He has, nevertheless, set up a company to pursue them. He foresees putting his discovery to use in more efficient domestic fridges and air conditioners. The real money, though, may be in cooling computers.
Gadgets containing microprocessors have been getting hotter for a long time. One consequence of Moore's Law, which describes the doubling of the number of transistors on a chip every 18 months, is that the amount of heat produced doubles as well. In fact, it more than doubles, because besides increasing in number, the components are getting faster. Heat is released every time a logical operation is performed inside a microprocessor, so the faster the processor is, the more heat it generates. Doubling the frequency quadruples the heat output. And the frequency has doubled a lot. The first Pentium chips sold by Dr Moore's company, Intel, in 1993, ran at 60m cycles a second. The Pentium 4--the last "single-core" desktop processor--clocked up 3.2 billion cycles a second.
Complete each of the following statements with the scientist or company name from the box below.
Write the appropriate letters A-F in boxes 1-5 on your answer sheet.
D. Alex Mischenko
E. Ali Shakouri
F. Rama Venkatasubramanian
1. ...and his research group use paraelectric film available from the market to produce cooling.
2. ...sold microprocessors running at 60m cycles a second in 1993.
3. ...says that he has made refrigerators which can cool the hotspots of computer chips by 10℃.
4. ...claims to have made a refrigerator small enough to be built into a computer chip.
5. ...attempts to produce better cooling in personal computers by stirring up liquid with tiny jets to make sure maximum heat exchange.
Do the following statements agree with the information given in the reading passage?
In boxes 6-9 on your answer sheet write
TRUE if the statement is true according to the passage
FALSE if the statement is false according to the passage
NOT GIVEN if the information is not given in the passage
See Paragraph 3: ...Alex Mischenko, of Cambridge University. Using commercially available paraelectric film, he and his colleagues have generated temperature drops...
See Paragraph 5: The first Pentium chips sold by Dr Moore's company, Intel, in 1993, ran at 60m cycles a second.
See Paragraph 8: ...Rama Venkatasubramanian, of Nextreme Thermal Solutions in North Carolina, claims to have made thermoelectric refrigerators that can sit on the back of computer chips and cool hotspots by 10℃.
See Paragraph 8: Ali Shakouri, of the University of California, Santa Cruz, says his are even smaller梥o small that they can go inside the chip.
See Paragraph 9: To improve on this, IBM's research laboratory in Zurich is experimenting with tiny jets that stir the liquid up and thus make sure all of it eventually touches the outside of the channel--the part where the heat exchange takes place.