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power plants that burn coal, natural gas or oil, no fuel would be required. The
environmental effects of geothermal power are “markedly lower” than either fossil
fuels or nuclear power. And unlike wind and solar systems, a geothermal plant works
night and day.
This environmental advantage is due to low emissions and the small overall
footprint of the entire geothermal system, which results because energy capture and
extraction is contained entirely underground, and the surface equipment needed for
conversion to electricity is relatively compact.
It’s not an easy objective, though. It costs a lot of money to drill wells in large
part because explorers need to drill deep into the earth, often 5,000 feet or more
below the earth’s surface. Meeting water requirements for geothermal plants may be
an issue, particularly in arid regions.
Further, the water that is used to create electricity must be kept separate from
drinking water supplies to prevent contamination. Additionally, the potential for
seismic risk from fluid injection needs to be carefully monitored. The cumulative
effect of all those obstacles has led skeptics to conclude that geothermal energy will
remain a nominal power source.
Peggy Daniels Becker, Alternative Energy
2. Make a presentation on one of the alternative sources of energy
successfully used in the world.
61
UNIT ELEVEN
1. Read the first paragraph of the article. What kind of material are
engineers from Stanford University working on?
2. Read the whole article and mark the statements as true (T) or false (F).
a) The resulting transistors are less than a centimeter thick._______
b) Organic transistors prove to be more efficient than their silicon
analogues._______
c) It takes just a little more than two months for the transistor to disappear in a
human organism._______
d) Being harmful for a patient, silver wires are not used in making medical
electronics. _____
e) There is no need in conducting any further tests to create working
devices.___
f) Beta-carotene (the molecule that gives cucumbers their colour) might, act
as a semiconductor._________
A desirable solution
Biodegradable electronics for medical devices take a step closer
The idea of creating biodegradable electronics for implantation
into the human body has been around for a couple of decades, but no one
has yet managed to do it. However, Zhenan Bao and Christopher
Bettinger, who are chemical engineers at Stanford University, have just
made a start. They have created transistors from a sulphur-containing hydrocarbon
called thiophene, a polyester called polylactide co-glycolide (PLGA, for short) and
polyvinyl alcohol (PVA). All of these chemicals are approved by America’s Food
and Drug Administration for human use.
62
To make their transistors, Dr Bao and Dr Bettinger chopped sheets of PLGA
into 1 cm squares and deposited thin silver contacts on to them. They then coated the
PLGA with thiophene, which acts as a semiconductor, interspersed with PVA, which
acts as an insulator. The result is a flexible transistor a few millimetres thick.
Such organic transistors are not as efficient and powerful as silicon transistors,
nor are they anything like as small. But they can be manufactured cheaply. More to
the point, they break down slowly in warm, salty conditions of the sort found in the
body. In laboratory tests intended to mimic the body’s interior, they disappeared after
70 days, leaving behind only the wires - which, being made of silver, are not toxic.
To create working devices it will be necessary to double-check that the other
ingredients are not toxic, too, despite their FDA clearance, and also to make the other
components of electrical circuits, such as capacitors and resistors, in a similar way.
Dr Bao is also investigating other compounds with potential uses in this area, such as
beta-carotene (the molecule that gives carrots their colour), which she thinks might,
like thiophene, act as a semiconductor. If she succeeds, it should be possible to devise
electrical control circuits for instruments such as drug-delivery devices that could be
implanted and then left alone to do their thing for a month or two before vanishing.
The Economist
3. Look at the italicized words and word combinations and explain what
they mean in your own words.
4. Speak on the technology of making a biodegradable transistor. Use the
words and word combinations from the box.
biodegradable electronics
sulphur-containing
hydrocarbon
polyester
to chop
to deposit
63
silver contact
to coat
semiconductor
to intersperse
insulator
transistor
5. Translate the article from Russian into English.
Химия - это наука о строении и превращении веществ. Условно, химию
можно разделить на две основных группы. Неорганическая химия изучает
свойства и реакции неорганических веществ. Органическая химия исследует
взаимодействие органических веществ, построенных на основе углеродной
цепочки. Химия может изучать вещества и реакции, протекающие внутри
живого организма. Этим занимается биохимия, а также молекулярная биология.
Так как химия занимается изучением строения и свойств веществ, то она очень
тесно пересекается с физикой. Несколько разделов химии можно также
рассматривать как разделы физики: квантовая химия, и физическая химия.
Аналитическая химия занимается анализом различных химических веществ с
целью установить структуру исследуемого вещества.
http://sci-lib.com/chemistry
64
SELF-ASSESSMENT XI
1. Translate the article using a dictionary.
Greener tyres
Using biomass and bugs to create synthetic rubber
Oil does not just provide the fuel that powers the internal-combustion engines
in cars. Its by-products are also the basis of many of the materials, such as plastics,
from which cars are made. One of these petroleum by-products is isoprene. This is
used to make the synthetic rubber in car tyres. About a billion tyres are made every
year - each one requiring about 26 litres of oil. Now a way has been found to make
greener tyres by using genetically modified bugs to produce isoprene biologically.
The work is being carried out by Genencor, an industrial biotech company
based in California, in collaboration with Goodyear, one of the world’s biggest
tyremakers. In the laboratory Genencor has produced enough of what it calls
BioIsoprene for Goodyear to build and successfully test prototype tyres made with
the new material. Genencor is now completing a dedicated pilot factory which will be
used to develop a mass-production process, which could be operating commercially
around 2015.
Isoprene is a monomer, which is a substance whose molecules can be linked
together chemically to form a polymer. Latex, a material obtained from rubber trees,
is a natural polymer of isoprene. Isoprene can also be artificially polymerised to make
synthetic rubber. Tyres are made of a combination of natural and synthetic rubber to
provide the grip and endurance required by carmakers. Typically around a quarter of
each tyre is made from isoprene derived from petrochemicals, and about 60% of
worldwide isoprene production is used by tyremakers. The rest goes into making
other products, including glues, disposable nappies and surgical gloves.
65
Genencor used a genetically modified form of E-coli, a favourite species of
bacteria in microbial genetics, to produce BioIsoprene. By splicing in genes from
other bugs, the company was able to engineer synthetic metabolic pathways - ones
that do not exist in nature - that enable the bacteria to produce isoprene from the
sugars found in plant materials such as sugar cane, corn cobs and switch grass.
The Economist
2. Write an essay to support the statement: “Chemistry is a science of
wonders”.
66
1. The Economist
2. http://sci-lib.com/chemistry
3. Peggy Daniels Becker, Alternative Energy
4. The New York Times
5. Mail Online
6. The Telegraph
7. Sanjay K. Mazumdar, Ph.D. COMPOSITES MANUFACTURING
8. http://anomalia.kulichki.ru/text6/189.htm
9. Practical Grammar. John Hughes and Ceri Jones. 2011 Heinle, Cengage
Learning.
10. http://promdesigns.ru/
СПИСОК ЛИТЕРАТУРЫ
11. http://znaeteli.ru/stati/interesnye-matematicheskie-fakty/
12. http://www.wood pellets.com/cgbin/cms/index.cgi?ext=content&pid
13. Use of English. Examination Practice. Virginia Evans. Express Publishing
2012.
14. Oxford Advanced Learner’s Dictionary.8 th edition .Sally Wehmeir. Oxford
University Press.
67
Учебное издание
Пономарева Светлана Александровна
Малинина Диана Александровна
YOUR MAJESTY SCIENCE
Редактор Р.А. Черникова
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