Recent IELTS Reading Actual test 78

You should spend about 20 minutes on Questions 1-13 which are based on Reading Passage 1 below.

History of Refrigeration

A

The term refrigeration refers to cooling an area or substance below the environmental temperature, the process of removing heat. Mechanical refrigeration uses the evaporation of a liquid refrigerant to absorb heat. The refrigerant goes through a cycle so that it can be reused, the main cycles are vapour-compression, absorption, steam-jet or steam-ejector, and air. Maryland farmer Thomas Moore first introduced the term Refrigerator in 1803, the appliance we know today first appeared in the 20th century.

B

Prior to mechanical refrigeration systems, people found different ways of preserving their food. Some people preferred to use cooling systems of ice or snow found either locally or brought down from mountains and sometimes stored in cellars. Using those techniques meant that diets would have consisted of very little fresh food or fruits and vegetables, but mostly of bread, cheese and salted meats. Milk and cheeses were difficult to keep fresh, they were usually stored in a cellar or window box, but despite those methods, they could not prevent rapid spoilage. People were more than ready for a better system of preserving food. Later on, it was discovered that adding chemicals like sodium nitrate or potassium nitrate to water caused the temperature to fall. Cooling wine with this technique was first recorded in 1550, as was the term “to refrigerate”. Cooling drinks became very popular by 1600 in Europe, especially in Spain, Italy and France. Instead of cooling water at night, people used a new technique; rotating long-necked bottles in water which held dissolved saltpeter. The solution was used to create very low temperatures and even to make ice. By the end of the 17th century, iced drinks including frozen juices and liquors were very popular in French society.

C

A demand for ice soon became very strong. Consumer demand for fresh food, especially produces, led to diet reform between 1830 and the Civil War, fueled by the dramatic growth of cities and the improvement in economic status of the general populace. And as cities grew, so did the distance between the consumer and the source of the food. In 1799, ice was first shipped commercially out of Canal Street in New York City to Charleston, South Carolina. The attempt was a failure as there was very little ice left when the shipment arrived. Frederick Tudor and Nathaniel Wyeth of New England saw the great potential that existed for the ice business and revolutionized the industry with their efforts in the first half of the 1800s. Tudor, who was known as the “Ice King”, was more focused on shipping ice to tropical climates. To ensure his product would arrive safely, he experimented with different insulating materials and built icehouses that decreased melting losses from 66 percent to less than 8 percent. Wyeth developed a method of cheaply and quickly cutting uniform blocks of ice that transformed the ice industry. He made speed handling techniques in storage, transportation and distribution possible, with less waste.

D

Eventually, it became clear that the ice being scraped was not all clean and was causing health problems. It was becoming an increasingly difficult task to find clean sources of natural ice and by the 1890s, pollution and sewage dumping had made the job seem even more impossible. The first signs were noticed in the brewing industry, and then the meatpacking and dairy industries became seriously affected. Some sort of clean, mechanical refrigeration was desperately needed.

E

Many inventive men were involved in the eventual creation of the refrigerator, through different discoveries that each built on the next. Dr William Cullen, a Scotsman, was the first to study the evaporation of liquids in a vacuum in 1720. He later demonstrated the first known artificial refrigeration at the University of Glasgow in 1748 by letting ethyl ether boil into a partial vacuum.

Olvier Evans, an American inventor, designed the first refrigeration machine to use vapor instead of liquid in 1805. Although he did not actually build it, an American physician named John Gorrie, produced one very similar to Evans’ in 1842 to cool the patients with yellow fever in a Florida hospital. His basic principle is still the most often used in refrigerators today. He found the best way to cool the air was by compressing a gas, then cooling it by sending it through radiating coils, and then expanding it to lower the temperature even more. Evans was granted the first U.S. patent for _mechanical refrigeration_ in 1851 after giving up his medical practice to focus on his experimentation with ice making.

In 1820 Michael Faraday, a Londoner, first liquefied ammonia to cause cooling. Ferdinand Carre of France developed the first ammonia/water refrigeration machine in 1859. Carl von Linde was also very influential in the creation of refrigeration. In 1873 he designed the first practical and portable compressor refrigeration machine in Munich and in 1876 he began using an ammonia cycle rather than the methyl ether he used in his earlier models. Linde later developed a new method (Linde technique) for the liquefaction of large quantities of air in 1894. The meatpacking industry in Chicago was the next to adopt mechanical refrigeration nearly a decade later.

F

Beginning in the 1840s, refrigerated cars were used to transport milk and butter. By 1860, refrigerated transport was limited to mostly seafood and dairy products. The refrigerated railroad car was patented by J.B. Sutherland of Detroit, Michigan in 1867. He designed an insulated car with ice bunkers in each end. Air came in on the top, passed through the bunkers, and circulated through the car by gravity, controlled by the use of hanging flaps that created differences in air temperature. There were different car designs based upon the type of cargo, whether meat or fruit. The first refrigerated car to carry fresh fruit was built in 1867 by Parker Earle of Illinois, who shipped strawberries on the Illinois Central Railroad. Each chest contained 100 pounds of ice and 200 quarts of strawberries. It was until 1949 that a refrigeration system made its way into the trucking industry by way of a roof-mounted cooling device, patented by Fred Jones.

G

Refrigerators that were built in the late 1800s to 1929 used the toxic gases; methyl chloride, ammonia and sulphur dioxide as refrigerants. There were numerous fatal accidents that occurred in the 1920s when methyl chloride leaked out of refrigerators. After the terrible incidents, three American companies began researching less dangerous methods of refrigeration. That research leads to the discovery of chlorofluorocarbons (Freon), which quickly became the standard used in compressor refrigerators. Freon was safer for those nearby but was later discovered in 1973 by Prof. James Lovelock, to be harmful to the ozone layer. To prevent further damage, new developments were made, such as Hydrofluorocarbons which have no known effect on the ozone layer. Chlorofluorocarbons are no longer used; they are outlawed in several places, making refrigeration far safer today than it has ever been.

Use the information in the passage to match the people (listed A-E) with opinions or deeds below.

Write the appropriate letter A-E in boxes 1-4 on your answer sheet.

A 1799

B 1803

C 1840

D 1949

E 1973

You should spend about 20 minutes on Questions 14-26 which are based on Reading Passage 2 below.

Renewable Energy

An insight into the progress in renewable energy research

A

The race is on for the ultimate goal of renewable energy: electricity production at prices that are competitive with coal-fired power stations, but without coal’s pollution. Some new technologies are aiming to be the first to push coal from its position as Australia’s chief source of electricity.

B

At the moment the front-runner in renewable energy is wind technology. According to Peter Bergin of Australian Hydro, one of Australia’s leading wind energy companies, there have been no dramatic changes in windmill design for many years, but the cumulative effects of numerous small improvements have had a major impact on cost. ‘We’re reaping the benefits of 30 years of research in Europe, without have to make the same mistakes that they did,’ Mr Bergin says.

C

Electricity can be produced from coal at around 4 cents per kilowatt-hour, but only if the environmental costs are ignored. ‘Australia has the second cheapest electricity in the world, and this makes it difficult for renewable to compete,’ says Richard Hunter of the Australian Ecogeneration Association (AEA). Nevertheless, the AEA reports: ‘The production cost of a kilowatt-hour of wind power is one-fifth of what it was 20 years ago,’ or around 7 cents per kilowatt-hour.

D

Australian Hydro has dozens of wind monitoring stations across Australia as part of its aim to become Australia’s pre-eminent renewable energy company. Despite all these developments, wind power remains one of the few forms of alternative energy where Australia is nowhere near the global cutting edge, mostly just replicating European designs.

E

While wind may currently lead the way, some consider a number of technologies under development have more potential. In several cases, Australia is at the forefront of global research in the area. Some of them are very site-specific, ensuring that they may never become dominant market players. On the other hand, these newer developments are capable of providing more reliable power, avoiding the major criticism of windmills – the need for back-up on a calm day.

F

One such development uses hot, dry rocks. Deep beneath South Australia, radiation from elements contained in granite heats the rocks. Layers of insulating sedimentation raise the temperatures in some location to 250° centigrade. An Australian firm, Geoenergy, is proposing to pump water 3.5 kilometres into the earth, where it will travel through tiny fissures in the granite, heating up as it goes until it escapes as steam through another drilled hole.

G

No greenhouse gases are produced, but the system needs some additional features if it is to be environmentally friendly. Dr Prue Chopra, a geophysicist at the Australian National University and one of the founders of Geoenergy, note that the steam will bring with it radon gas, along through a heat exchanger and then sent back underground for another cycle. Technically speaking, hot dry rocks are not a renewable source of energy. However, the Australian source is so large it could supply the entire country’s needs for thousands of years at current rates of consumption.

H

Two other proposals for very different ways to harness sun and wind energy have surfaced recently. Progress continues with Australian company EnviroPower’s plans for Australia’s first solar chimney near Mildura, in Victoria. Under this scheme, a tall tower will draw hot air from a greenhouse built to cover the surrounding 5 km². As the air rises, it will drive a turbine* to produce electricity. The solar tower combines three very old technologies – the chimney, the turbine and the greenhouse – to produce something quite new. It is this reliance on proven engineering principles that led Enviropower’s CEO, Richard Davies, to state: There is no doubt this technology will work, none at all.’

I

This year, Enviropower recognized that the quality of sunlight in the Mildura district will require a substantially larger collecting area than was previously thought. However, spokesperson kay Firth says that a new location closer to Mildura will enable Enviropower to balance the increased costs with extra revenue. Besides saving in transmission costs, the new site ‘will mean increased revenue from tourism and use of power for telecommunications. We’ll also be able to use the outer 500 metres for agribusiness.’ Wind speeds closer to the tower will be too high for farming.

J

Another Australian company, Wavetech, is achieving success with ways of harvesting the energy in waves. Wavetech’s invention uses a curved surface to push waves into a chamber, where the flowing water column pushes air back and forth through a turbine. Wavetech was created when Dr Tim Devine offered the idea to the world leader in wave generator manufacturers, who rather surprisingly rejected it. Dr Devine responded by establishing Wavetech and making a number of other improvements to generator design. Wavetech claims that, at appropriate sites, ‘the cost of electricity produced with our technology should be below 4 cents per kilowatt-hour.

K

The diversity of forms of greenhouse – friendly energy under development in Australia is remarkable. However, support on a national level is disappointing. According to Richard Hunter of the AEA, ‘Australia has huge potential for wind, sun and wave technology. We should really be at the forefront, but the reality is we are a long way behind.’

Do the following statements agree with the information given in Reading Passage 2?

In boxes 14-20 on your answer sheet, write

TRUE if the statement agrees with the information

FALSE if the statement contradicts the information

NOT GIVEN if there is no information on this

You should spend about 20 minutes on Questions 27-40 which are based on Reading Passage 3 below.

THE GAP of INGENUITY 2

A

Ingenuity, as I define it here, consists not only of ideas for new technologies like a computer or drought-resistant crops but, more fundamentally, of ideas for better institutions and social arrangements, like efficient markets and competent governments.

B

How much and what kinds of ingenuity a society requires depends on a range of factors, including the society’s goals and the circumstances within which it must achieve those goals – – whether it has a young population or an aging one, an abundance of natural resources or a scarcity of them, an easy climate or a punishing one, whatever the case may be.

C

How much and what kinds of ingenuity a society supplies also depends on many factors, such as the nature of human inventiveness and understanding, the rewards an economy gives to the producers of useful knowledge, and the strength of political opposition to social and institutional reforms.

D

A good supply of the right kind of ingenuity is essential, but it isn’t, of course, enough by itself. We know that the creation of wealth, for example, depends not only on an adequate supply of useful ideas but also on the availability of other, more conventional factors of production, like capital and labor. Similarly, prosperity, stability and justice usually depend on the resolution, or at least the containment, of major political struggles over wealth and power. Yet within our economies ingenuity often supplants labor, and growth in the stock of physical plant is usually accompanied by growth in the stock of ingenuity. And in our political systems, we need great ingenuity to set up institutions that successfully manage struggles over wealth and power. Clearly, our economic and -political processes are intimately entangled with the production and use of ingenuity.

E

The past century’s countless incremental changes in our societies around the planet, in our technologies and our interactions with our surrounding natural environments, have accumulated to create a qualitatively new world. Because these changes have accumulated slowly, it’s often hard for us to recognize how profound and sweeping they’re. They include far larger and denser populations; much higher per capita consumption of natural resources; and far better and more widely available technologies for the movement of people, materials, and especially information.

F

In combination, these changes have sharply increased the density, intensity, and pace of our interactions with each other; they have greatly increased the burden we place on our natural environment; and they have helped shift power from national and international institutions to individuals and subgroups, such as political special interests and ethnic factions.

G

As a result, people in all walks of life—from our political and business leaders to all of us in our day-to-day— —must cope with much more complex, urgent, and often unpredictable circumstances. The management of our relationship with this new world requires immense and ever-increasing amounts of social and technical ingenuity. As we strive to maintain or increase our prosperity and improve the quality of our lives, we must make far more sophisticated decisions, and in less time, than ever before.

H

When we enhance the performance of any system, from our cars to the planers network of financial institutions, we tend to make it more complex. Many of the natural systems critical to our well-being, like the global climate and the oceans, are extraordinarily complex, to begin with. We often can’t predict or manage the behavior of complex systems with much precision, because they are often very sensitive to the smallest of changes and perturbations, and their behavior can flip from one mode to another suddenly and dramatically. In general, as the human-made and natural systems, we depend upon becoming more complex, and as our demands on them increase, the institutions and technologies we use to manage them must become more complex too, which further boosts our need for ingenuity.

I

The good news, though, is that the last century’s stunning changes in our societies and technologies have not just increased our need for ingenuity; they have also produced a huge increase in its supply. The growth and urbanization of human populations have combined with astonishing new communication and transportation technologies to expand interactions among people and produce larger, more integrated, and more efficient markets. These changes have, in turn, vastly accelerated the generation and delivery of useful ideas.

J

But—and this is the critical “but” we should not jump to the conclusion that the supply of ingenuity always Increases in lockstep with our ingenuity requirement: while it’s true that necessity is often the mother of invention, we can’t always rely on the right kind of ingenuity appearing when and where we need it. In many cases, the complexity and speed of operation of today’s vital economic, social, arid ecological systems exceed the human brain s grasp. Very few of us have more than a rudimentary understanding of how these systems work. They remain fraught with countless “unknown unknowns, which makes it hard to supply the ingenuity we need to solve problems associated with these systems.

K

In this book, explore a wide range of other factors that will limit our ability to supply the ingenuity required in the coming century. For example, many people believe that new communication technologies strengthen democracy and will make it easier to find solutions to our societies, collective problems, but the story is less clear than it seems. The crush of information in our everyday lives is shortening our attention span, limiting the time we have to reflect on critical matters of public policy, and making policy arguments more superficial.

L

Modem markets and science are an important part of the story of how we supply ingenuity. Markets are critically important because they give entrepreneurs an incentive to produce knowledge. As for science, although it seems to face no theoretical limits, at least in the foreseeable future, practical constraints often slow its progress. The cost of scientific research tends to increase as it delves deeper into nature. And science’s rate of advance depends on the characteristic of the natural phenomena it investigates, simply because some phenomena are intrinsically harder to understand than others, so the production of useful new knowledge in these areas can be very slow. Consequently, there is often a critical time lag between the recognition between a problem and the delivery of sufficient ingenuity, in the form of technologies, to solve that problem. Progress in the social sciences is especially slow, for reasons we don’t yet understand; but we desperately need better social scientific knowledge to build the sophisticated institutions today’s world demands.

Complete each sentence with the appropriate answer, A, B, C, or D.

Write the correct answer in boxes 27-30 on your answer sheet.

A depends on many factors including climate.

B depends on the management and solution of disputes.

C is not only of technological advance but more of institutional renovation.

D also depends on the availability of some traditional resources.