GGCCSSEE SScciieennccee RReevviieeww Volume 13Number 1September 2002

CyborgsThe next step in evolution?

EDITORIAL TEAM

Nigel CollinsKing Charles I School,

Kidderminster

David MooreSt Edward’s School, Oxford

David SangAuthor and editor

Jane TaylorSutton Coldfield Grammar

School for Girls

Editorial telephone01562 753964

ADVISORY PANEL

Eric AlboneClifton Scientific Trust

Tessa CarrickFounder Editor, CATALYST

David ChaundyFounder Editor, CATALYST

Peter FinegoldThe Wellcome Trust

Roland JacksonScience Museum

Chantelle JayBiotechnology and Biological

Sciences Research Council

Peter JonesScience Features, BBC

David KneeCREST Awards

Ted ListerRoyal Society of Chemistry

Founder Editor, CATALYST

Ken MannionSheffield Hallam University

Andrew MorrisonParticle Physics and

Astronomy Research Council

Jill NelsonBritish Association

Silvia NewtonCheshunt School

and Association for Science Education

Toru OkanoThe Rikkyo School in England

John RhymerBishop’s Wood Environmental

Education Centre

Julian SuttonTorquay Boys’

Grammar School

Nigel ThomasThe Royal Society

Plastics: an insoluble problemDavid Moore 1Improve your gradeRevision 4Hearing the world around usDamian Murphy 6Try thisInvestigating sound 9A life in scienceKevin Warwick 10Where have all the skylarksgone?Chris Mead 12For debatePigeons or peregrines? Should predators be preserved? 16Places to visitEarth Centre 18Your futureChemical engineering 20Chemical plant 22The front cover shows Arnold Schwarzenegger as theTerminator (Hemdale Film Corp/RGA). See pages10–11.

© PHILIP ALLANUPDATES 2002ISSN 0958-3629

Publishing Editor: Jane Buekett.

Artwork: Gary Kilpatrick.

Reproduction by DeMontfort Repro, Leicester.

Printed by Raithby,Lawrence and Company,

Leicester.

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EditorialWelcome to issue 1!

Welcome to the first issue in a new

volume of CATALYST. Some of you will

be starting out on your GCSE science course;

for others, your second year is beginning

and the end of the course is just coming into

view. Whichever applies to you, we hope

that CATALYST will be an interesting and use-

ful companion along the way.

Each issue of CATALYST includes several

articles on aspects of science which are rel-

evant to your course — look for the GCSE

key words box near the start of the article.

These articles should help to reinforce the

ideas you are studying. At the same time,

they will help you to learn about the fron-

tiers of science — many are written by prac-

tising scientists describing the research they

are involved with at present.

What else will you find in CATALYST?

• In each issue Improve Your Grade sug-

gests ways in which you can improve your

revision techniques, make effective notes

or write better exam answers.

• Your Future describes an area of scien-

tific work which might be a possible

career for you.

• Scientists do experiments, so most issues

include one to try.

• A Life in Science looks at the work of a

particular scientist — useful in under-

standing how ideas in science have

developed.

Lastly, we try to include a puzzle in each

issue. These are just for fun, but if you

enjoy getting to grips with a good puzzle,

that could mean you would make a good

scientist. Scientists spend a lot of their time

struggling with quite tricky puzzles — and

there are no answers at the back to help

them on their way.

Enjoy your CATALYST!

David Sang

1September 2002

Imagine the Time Team excavating a site at sometime in the future. What will they make of largeholes in the ground which have been filled with

tonnes of plastic before being covered with soil?Unlike discarded metal washing machines, wastepaper and cardboard, plastic does not decomposeonce it has been thrown away. What can be done tochange this, how can we recycle plastics, and can wemake plastics that dissolve?

PLASTICS WHICH WASH AWAY

To start at the end, yes, plastics which will dissolvein water have been known for quite some years.They are used in hospitals to make laundry bags.Panels within the bag are made of dissolving plastic.Soiled sheets and clothes can be put in the bag andthe whole bag placed in a washing machine withouthandling the dirty laundry again. Once the hot wateris in the machine the plastic dissolves and simplywashes away, leaving the clothes and sheets free tobe washed. How does this happen?

The plastic is made from chains of polymer calledpoly(ethenol) which has OH groups on every othercarbon of the polymer chain (Figure 1). These canform a special type of bond, called a hydrogen bond,with water, and so dissolve. Table 1 shows how thepercentage of OH groups affects the dissolving prop-erties of this type of plastic. Some shops now offerthese ecologically-friendly plastic bags in an attemptto reduce the litter problem caused by waste plastics.

DAVIDMOORE

As part of your GCSE course you will be

looking at plastics and their uses — but have

you wondered what happens to them once

they are discarded?

GCSE key wordsPolymer

Polyethene

PlasticsAn insoluble problem

OH OH OH

Figure 1 The structure of poly(ethenol).

OH groups (%) Solubility in waterBelow 90 Soluble in cold water90–96 Soluble in warm water97–98 Soluble in hot water99–100 Insoluble

Table 1 Relationship between percentage of OHgroups on alternate carbons of the polymer chain,and solubility of the plastic

Top: Plastic bagscause a serious litterproblem becausethey blow aboutand do notdecompose.

Above: Plasticbottles forrecycling.

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WHERE DID PLASTICS FIRST COME FROM?

Polyethene — the main material from which plasticbags are made — was first invented in 1933 by EricFawcett and Reginald Gibbon who worked for ICIin Cheshire. Polyethene was discovered accidentally.Both men were trying to make a totally differentcompound, but kept obtaining a white waxy solid.At first they couldn’t find anything to do with it andso it remained a curiosity. However it was found tobe both chemically and electrically inert and so wasused in the Second World War to shield the circuitryin radar apparatus from stray electrical fields. It wasalso used as a protective sheath to prevent waterattacking undersea cables.

The first polyethene produced melted just abovethe boiling point of water. It wasn’t until 1953 thata German chemist, Karl Ziegler, refined the manu-facturing process to produce high-density polyethene(see Box 1), which was far more stable to heat andvery durable.

Nowadays the starting materials for plastics man-ufacture come from the petrochemical industry. Theethene is obtained from distillation and cracking inoil refineries. Most plastics can be readily moulded,are chemically inert, have good strength propertiesand, weight for weight, are both more flexible andstronger than steel.

CAN WE RECYCLE PLASTICS?

To a limited extent, yes, we can. If you look at thebottom of a plastic drinks bottle you will find anembossed triangle with a number in it. The number,which varies between 1 and 7, tells you what plasticthe item is made from (see Table 2).

2 Catalyst

A normalhousehold can use

more than 1000carrier bags a year.

Britain’s annualplastic bagmountain

weighs over 145 000 tonnes.

l See how manyof the different

types of plastic inTable 2 you canfind around the

home. Sort themand work out

whether there areany relationships

between theircode number andthe use to which

they are put.

BOX 1

Polymers (or plastics) are long molecules made up ofchains of carbon atoms. These polymers are made byjoining many thousands of small molecules — calledmonomers — together:

A + A + A + A + A… → A−A−A−A−A…Polymers which are soft and springy and will

regain their original shape after being stretched arecalled elastomers. Polymers which remain deformedafter being stretched are called plastics while thosewhich can be made into strong thin threads arecalled fibres.

High-density polyethene is made up of longchains of carbon atoms. These chains are notbranched, so they can lie close to each other. Thisallows strong interactions to occur between thechains and the polymer becomes strong and tough.Low-density polyethene is made up of branchedchains which cannot lie close to each other. Theforces between chains are therefore weaker and thepolymer is more flexible and not tough.

Table 2 Recycling numbers

Number

7OTHER

6PS

7

5PP

6

4LDPE

5

3V

2HDPE

3

1PETE

2

Plastic

Polyethylene terephthalate

High-density polyethene

Polychloroethene (PVC)

Low-density polyethene

Polypropene

Polystyrene

Other

Uses

Drinks bottles, water bottles, vinegar bottles, medicine containers, backing forphotography film

Containers for laundry/dishwashing detergent, fabric softeners, bleach, milk,shampoo, conditioner, motor oil. Newer bullet-proof vests, various toys

Pipes, shower curtains, meat wraps, cooking oil bottles, shrink wrap, clearmedical tubing, coffee containers

Wrapping films, grocery bags, sandwich bags

Tupperware®, syrup bottles, yogurt tubs, outdoor carpet

Coffee cups, disposable cutlery and cups (clear and coloured), bakery shells,meat trays, ‘cheap’ hubcaps, packing peanuts, insulation

Products labelled ‘other’ are made of any combination of 1–6 or another, lesscommonly used, plastic

The triangle on the bottom of a plastic bottle tellsyou what it is made of (see Table 2).

l The Irishgovernment hasintroduced a taxon plastic carrierbags (about 9p abag). How much

would your familyspend a year onbags if we had

such a tax here?

3September 2002

An average carrierbag will hold morethan 10 kg of foodwithout breaking.

99% of all carrierbags are usedtwice: once to putshopping in andthen to putrubbish in, beforebeing thrownaway.

l Take a bag withyou when you goshopping and tryto avoid collectingany more carrierbags. See howdifficult it is!

Above: How manyof the differenttypes of plastic inTable 2 can youspot here?

The main problem with recycling is that in a batchof household waste there may be plastics with manydifferent numbers. A bottle top may be made from adifferent plastic to the bottle itself. An article of cloth-ing may be made from mixtures of many types ofpolymer fibre, each with its own properties to enablethe clothing to function properly. The difficulty comeswith separating all the plastics into their differenttypes before or after they are collected — some plasticsmay not even have a recycling number on them.

Councils that do separate plastics from otherhousehold waste often leave them mixed — oncecleaned and re-melted they produce a low-qualityplastic which may be used for packaging purposes.Plastic has to be heated carefully during recycling tostop it decomposing and releasing carbon particlesthat would contaminate and weaken it.

ARE THERE ALTERNATIVES TO PLASTICS?

Yes, there are many, but they may not have all thedesired properties of a plastic. Extruded cellulose is

now commonly used as a packaging material forfragile objects, but if it gets wet the cellulose softensand the structure collapses to a paste. A strongcomposite of laminated wood and reclaimed plastichas been made using a special chemical called a graftcopolymer to join the two together. In the pastobjects made from fusing together wood and plastichave often failed to last. This is because plastics areessentially oily substances while wood consists ofwater-loving molecules, and the two don’t easilycoexist.

PLASTIC, PLASTIC, EVERYWHERE

Plastic carrier bags were first introduced into shopsin 1968 and are now found all over the world —quite literally! In some of the poorest countries theyare a status symbol and are re-used many times. Butwhen it comes to litter they are a major problembecause they tend to last for ever. They weigh solittle that they blow about and are both a visualeyesore and a hazard to wildlife.

Perhaps we should be more like the Swedish, whohave large resources of wood and tend to use farmore paper bags than plastic ones. Surprisingly thisis also true of Americans who tend to use the poten-tially more fragile paper sack instead of the plasticcarrier bag. Even if the paper of the bag is not recy-cled, at least it will decompose once it is in theground — unlike plastic.

It is up to all of us to try and cut down on the useof plastic, in particular plastic bags, or in the futurewe will be submerged in a sea of plastic. The alter-natives are out there — it is up to us to use them.

David Moore teaches chemistry at St Edward’sSchool in Oxford and is an editor of CATALYST.

A woman in the market in Minsk, Belarus, sellingWestern carrier bags to shoppers.

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We want to help you with your exams.During the year Improve Your Gradewill help you improve your revision

techniques, show you how to make effective notesand help you write better exam answers. Some ofyou have mocks coming up, so in this issue we arelooking at revision and learning.

QWhen should I start revision?

AYou might not need help with this, but manypeople find it difficult to overcome the psycho-logical barrier and actually start revising. Theymake revision timetables, finish off bits of home-work which aren’t due for a week, tidy some deskspace, sharpen their pencils and so on. Of coursethese are all good things to do, but they do put offthe evil moment. If you find you are brushingyour teeth before you open your physics notesstop procrastinating and get on with it. Doregular small amounts of revision interspersedwith your normal work in the weeks before theexams. It’s never too late to do some revision, butit can be too early.

Q What do you mean by ‘it’s too early to do revision’?

A Make sure you know the difference betweenlearning and revision. Revision refreshes andreminds you of what you already know — it isn’tlearning things for the first time. It should bedone just before your exams and shouldn’t takevery long. Learning is what takes the time. Areyou waiting to learn your topics until just beforethe exams? If so you are making your lifedifficult. You must do your learning well in

advance and leave the time in the weeks beforeexams for true revision and learning the mostrecent work.

Q When is the best time to learn the topics?

A You learn all the time — obviously you are learn-ing while you are in lessons and when you doyour homework. You also need to set asideregular amounts of time during the week to learnthe topics you have recently studied. It needn’t bea long session, but remember that every activityyou do helps you to learn. The more you have tothink about and do things the more likely you areto remember them. For example, you tend toremember practical activities that you did your-self better than those you watched your teachersdo or read about in books.

Break down the module of work into sub-sec-tions. Figure 1 is a spider diagram showing howa biology module on control and coordinationcan be broken down into smaller sections. Setaside small amounts of time for learning eachsub-section as you go along — ideally shortlyafter the block of lessons on that topic. By thetime you get to the end-of-module test you willalready have learnt most of the work and needonly learn the last bit and revise the rest.

Q What can I do to help my learning?

A First of all, don’t be lazy when doing homework.If, for example, the homework is ‘read page 73and answer questions 1, 3 and 4’ don’t just readthe questions and scan the page for the lines cov-ering the answers. Read the page properly — itgives a context for the information in the answersand that will help them to stick.

When you are learning try the following activ-ities which involve you processing information. (1) Visit the school library with your exercisebook and a note pad. Find a book that isn’t yourtextbook, or a CD-ROM that covers your topic,read about your topic and check that your notesare accurate. Watch any animations. Make cribnotes of everything in your note pad. The cribnotes themselves aren’t important, but writingthem down is. The processing of information thatyou do while making the notes helps you remem-ber them. The fact that the information is pre-sented in a different way from your textbook alsohelps you remember. Some people find it easier toremember pictorial information than words.(2) Make a spider diagram of the topic and turn itinto a concept map by adding the links betweenwords (see Figure 3, and Improve Your Grade

4 Catalyst

IMPROVEyour grade Revision

Control and coordination

Nervous system

Animal hormones

Plant hormones

Response to light direction

Auxin

Rooting powder Fruit

ripening

Synapse

InsulinAdrenalin

Control of blood sugar

‘Fight or flight’

Control of fertility

Reflexes

Effect of drugs

Other hormones

Oestrogen and progesterone

Central nervous system

Structure of neurone

Figure 1 Spiderdiagram for controland coordination.

Control and coordination

Homeostasis

Action

Diabetes

InsulinKidney

Kidney tubule

ADH

UrineGlycogen

Adrenalin and glucagon

Endocrine glands

Adrenal gland

Anabolic steroids

Pancreas

Ovary

Testis

Blood sugar

Water content of blood

Animal hormones

Chemicals used to coordinate body activity

Regulates body processes

Slow,�long

lasting

Made by

Done in

AtLess

Stored in �liver as

Makes adrenalin

Abused by athletes

Makes insulin

Makes testosterone

Makes oestrogen and progesterone

Water reabsorbed into body

Except

Regulated within limits

Fail to regulate

Brings down level

Releases sugar from

storage

Glucose converted to

Promotes release

Regulated within limits

Adrenalin

indicates further links could be made

Figure 3 Part of aconcept map of controland coordination.

about making concept maps in CATALYST Vol. 11,No. 3). You will have to think about the relation-ships between the topics. Even better, work with afriend. As you argue about a diagram you have toformulate your ideas and turn your thoughts intospeech, which helps you remember.(3) Use study support clubs to straighten out dif-ficulties.

(4) Don’t waste time on random internetsearches — much of what you find will berubbish. Instead use guides to useful sites like theone in CATALYST Vol. 12, No. 2, GCSE Bitesizeand the National Curriculum website.

Jane Taylor teaches biology and is an editor of CATALYST.

5September 2002

14 October Week 2 If you work a fortnightly timetable

Monday Tuesday Wednesday Thursday Friday

Homework Maths English RE Maths Englishquestions essay, due Thur plan discussion questions poetry

Spanish Geog DT French DTvocab, notes coursework questions courseworktest next lesson

Business studies Science Business studies Science Geogcoursework write expt coursework revise read and plan

Tests Spanish tomorrow Biology test Mon.

Coursework Business studiesDT

Review Review Revise Review Revisecontrol of blood Spanish Treaty of Versailles control andsugar, adrenalin coordination

Figure 2 An example of a revision timetable.

Stereophonic sound has been around for over30 years, and multi-speaker techniques arenow commonplace in cinema sound systems,

home cinema and DVD systems. They give a more‘immersive’ feel to the sounds you hear. Your PCmay have surround-sound enhancements for gamesand other entertainment software. This ‘three-dimen-sional audio’ can also be produced using standardheadphones or stereo speakers together with precisemeasurements of the detailed physical characteristicsof a person’s head and ears.

For accurate surround-sound two things need tobe taken into account. First, the environment inwhich it is heard — a room, a corridor, the middleof a field — affects the quality of a sound, and weneed to be able to understand and recreate this.Second, our hearing system is designed to give usinformation about where a sound is coming from.This is a basic survival mechanism enabling us to runaway from sounds associated with danger (e.g. astampeding woolly mammoth, or an approachingfast car). Our sense of direction is very finely tuned,and for convincing surround-sound we need to knowmore about how our ears give us this directionalinformation.

IMPULSE RESPONSE OF A ROOM

The size, shape and materials of a room all play apart in the quality of any sound heard within it.Imagine a gun being fired inside a large room orhall. This short, sharp and very loud event causesvariations in the air pressure (known as compres-sions and rarefactions) that are transmitted throughthe air itself, spreading out into the room in everydirection — a sound wave.

Figure 1 shows how a sound wave travels across a room. When it strikes objects in the room, it is

6 Catalyst

DAMIANMURPHY Hearing the world around us

GCSE key wordsSound waves

Reflection

Diffraction

In your GCSE science course you will learn

about how sound waves are affected by their

surroundings as they travel. Engineers are

using this understanding to develop highly-

realistic sound systems for films, music systems

and computer games. The same ideas can help

people with eyesight and hearing problems.

Damian Murphy of York University describes

how this is done.

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partially absorbed and partially reflected. There mayalso be diffraction effects, where the sound bendsround an object or passes through a gap (such as anopen door), resulting in further spreading of the orig-inal sound wave. It is because of diffraction that wecan hear through an open door or window. Veryquickly (within 100 ms) the sound from our gunshothas spread through the room, having been reflected,absorbed and diffracted, resulting in a very complexand random pattern of sound.

MEASURING SOUND

The example of a gunshot sound is used because itcontains all the audio frequencies in which we areinterested at equal amplitudes. We can describe thecomplex way the room affects this sound using asingle measurement called the impulse response. Wemeasure the variation in air pressure using a micro-phone (or just by listening to the sound) at a point inthe room. We can examine how each frequency hasbeen changed by its interactions with the room.

The impulse response itself is not very interestingto listen to. It lasts anywhere between 0.1 and 10seconds depending on the size of the room and howreflective the surfaces are, and sounds like a clickwith a prolonged and decaying tail. This decaying

part of the impulse response is due to the reverbera-tion present in the room and is the characteristic‘hanging on’ quality of a sound that can be heardonce the sound source itself has become silent.Reverberation can, for example, be heard quiteclearly in an empty church. It is possible to take thisvery boring sound and combine it electronically withany other sound — for example, a piece of music.We can make the music sound as though it is comingfrom inside any particular space, as long as we knowthe impulse response of that environment.

The impulse response of a room can be measureddirectly, but for most applications it is more practicalto calculate an approximation using an acousticmodel. Figure 2 (above) shows how the acoustics of aroom can be modelled using a computer simulation.

7September 2002

Figure 2 A sound wave caused by the computer equivalent of a gunshotpropagating through a mesh structure that is designed to simulate a room.Notice the reflections at the boundaries and the diffraction effects in thepartitioned area, caused by gaps in the dividing wall. In the background is atypical room impulse response obtained from such a model.

l Most pop musicvocal recordingstake place in smallrooms or boothsyet the results wehear on a CD havea very differentacousticcharacteristic.What do theysound like? Whydo you think thisis?

Figure 1 (a) A sound wave spreads out into theroom. (b) It is partly reflected and partly absorbedby the walls. (c) It is diffracted as it passes through adoorway into the room beyond. (d) After a while,both rooms are filled with a random jumble of low-amplitude sound waves.

around us

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(a) (b) (c) (d)

Diffraction effects

Partition

Reflectionby wall

IMPULSE RESPONSE OF THE EAR

Just as the room around us affects the sounds wehear, so does the shape and structure of our head,but on a much smaller scale.

A sound coming to us from one side arrives at oneear slightly before the other and its amplitude is dif-ferent at each ear. Sound waves diffract around thehead, and undergo minute reflections in the pinnae(the fleshy parts of the outer ears). This alters the fre-quency content of the sound that reaches the ear-

drums and is how we know which direction thesound has come from.

Every person’s head affects sounds in its own waybecause we all have heads and outer ears of differentsizes and shapes.

If we measure the room impulse response at theentrance to the listener’s ears we can find out howsounds are affected by both the room and the lis-tener’s head and ears. It can be electronically com-bined with any audio source. A sound can then beplaced at any position in a three-dimensional virtualspace around the listener’s head, and reproducedusing only headphones (or stereo speakers) (seeFigure 3).

THE GOAL

Sound research can be valuable in producing aids forboth visually and hearing-impaired people, forexample:• improved hearing-aids;• audio guides for popular tourist attractions;• computer interfaces that translate visual informa-

tion into a virtual surround-sound space byplacing ‘audio icons’ around the listener’s head.

The ultimate scientific goal in surround-sound is toelectronically generate a complex three-dimensionalacoustic world that is indistinguishable from whatwe normally hear around us. As well as work withthe visually impaired, this technology has applica-tions in music composition, sound reproduction, art,architectural design, cinema, telecommunications,user-interface design, television and gaming enter-tainment. The result is accurate, exciting surround-sound effects.

Damian Murphy is in the Department of Electron-ics at the University of York.

8 Catalyst

Some owls haveone ear higherthan the other.

This is thought togive them a betterthree-dimensional

picture of thesounds aroundthem in a dark

wood.

l Next time yougo to the cinema,listen carefully to

the sound youhear around you.

What can you hearfrom each set ofspeakers? How

good is thesurround-sound

effect?

Figure 3 A mannequin and speaker used in themeasurement of the head-related impulse response.A dummy is often used because it stays still whenthe measurements are being made. In thebackground is a three-dimensional graph of themeasured head-related impulse responses showinghow frequencies vary with the direction of thesound, and also a model of the outer ear.

Damian Murphy with the mannequin head.

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9September 2002

Investigating sound

T R Yt h i s

Birds puzzleUse the words in the list to complete the wordsquare.Answers on page 15.

K

3-LETTER WORDS

AUKEMUJAY

OWL

4-LETTER WORDS COOTCROWDOVEDUCKHAWK

IBISKIWILARKRAILRHEASWANTERNWREN

5-LETTER WORDS BOOBYDIVERFINCHGOOSEHERONMACAWSTORKSWIFT

WADER

6-LETTER WORDS

CUCKOOFALCONGANNETGROUSEPLOVERPUFFIN

THRUSHTOUCANTURKEY

7-LETTER WORDS

OSTRICHPELICANPENGUIN

SWALLOWWARBLER

8-LETTER WORDS

NIGHTJARPARAKEETPHEASANT

9-LETTER WORDS

PARTRIDGESPOONBILL

10-LETTER WORDS

KINGFISHERWOODPECKER

Check out some of the ideas in ‘Hearing theworld around us’ (pages 6–8):

• Do your own impulse response test. Clap yourhands loudly, once, listen carefully and you willhear the impulse response of the room as yourhandclap reverberates and quickly dies away.

• You can hear an echo if it arrives at your ears atleast 100 ms after the original sound. What is theshortest length of room for us to hear a distinctecho from sound reflecting off the far wall (speedof sound in air = 330 m/s)?

• Why do people like singing in the shower? Thinkabout the physical properties of a typical bath-

room compared with those of a living room. Whateffect will they have on a person’s voice?

• We use the differences in timing and amplitude ofa sound at each of our ears (together with the position-dependent frequency characteristics) towork out where a sound is coming from. Whatother physical mechanism (apart from vision) dowe use to precisely locate a sound source?

• The fronts and backs of ears have very differentshapes. Why do you think this is? Accentuate thisdifference by cupping a hand round each of yourears. How do the sounds around you change asyou move your head around?

The array which was implanted in Kevin’s wristcontains 100 spikes with sensitive tips, each ofwhich make direct connections with nerve

fibres. This sophisticated implant allows a two-wayconnection to the nervous system. In one directionthe natural activity of nerves is detected, and in theother direction nerves can be activated by appliedelectrical pulses. Wires linked to the array have beentunneled up Kevin’s arm, and emerge through a skinpuncture 15 cm away from the array. These arejoined to a novel radio transmitter/receiver devicewhich links Kevin’s median nerve to a computer bymeans of a radio signal.

Such neural connections may lead to medical benefits for a large number of people. In particularthey might be used to assist movement in peoplewho have suffered spinal cord injury or limb ampu-tation.

PUSHING BACK THE FRONTIERS

Dr Kevin Warwick is Professor of Cybernetics at theUniversity of Reading where he carries out researchin artificial intelligence, control and robotics. Hisfavourite topic is pushing back the frontiers ofmachine intelligence.

10 Catalyst

Norbert Weinerfounded the field of

cybernetics in the1940s in the USA. He

believed that oneday ‘nervous

prostheses’ would bedeveloped which

would allow peoplewith spinal injuries to

control theirparalysed limbs using

signals detected intheir brain.

You may havewatched The Royal

Institution ChristmasLectures on

television. Kevinpresented them in

the year 2000, withthe title ‘Rise of the

Robots’.

A L I F Ein science

Kevin Warwick

On 14 March 2002, at 8.30 a.m., an operation

was carried out at the Radcliffe Infirmary,

Oxford to implant a microelectrode array onto

the median nerve in the arm of Professor Kevin

Warwick. The surgery, which lasted just over

2 hours, went very well and was declared a

success. It was the world’s first operation of

this type. But what of Kevin’s life before this?

How did he become the first cyborg — a

human and machine joined together? The array which was implanted in Kevin’s wrist.iC

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s

Kevin was inspired to start thinking objectivelyabout the human brain when he was a child and hisfather had a successful neural operation. ReadingH. G. Wells and watching Dr Who led him to thinkabout what might be possible using machines andscience.

Kevin began his career by joining British Telecom,where he worked for 6 years, the first 3 years as anapprentice. He learnt a lot of science by takingmotorcycles apart and trying to make them go fasterthan they should.

At 22 he took his first degree, a BSc in electricaland electronic engineering, at Aston University. Thiswas followed by a PhD and a research post at Impe-rial College, London. He subsequently held posi-tions at Oxford, Newcastle and Warwick universitiesbefore taking up the professorship at Reading in1988, at the age of 32. He is married and has twochildren.

THE FIRST CYBORG

In 1998 Kevin shocked the international scientificcommunity when he had his first implant — a siliconchip transponder in his left arm. The implanted chipemitted a unique identifying signal which allowed a

computer to monitor him as he moved through thehalls and offices of the Department of Cybernetics.He could operate doors and switch on lights, heatersand other computers without lifting a finger.

This article was written soon after the secondoperation. You can find updates about what hap-pened on Kevin’s website http://www.kevinwarwick.

com. There is more in Kevin’s latest book I, Cyborg,which was published in August by Century. Thisgives more details of his life and the events followingon from the implant last March.

Kevin has published over 350 research papers andhis paperback In the Mind of the Machine (pub-lished by Arrow in 1998) warns of a future in whichmachines will be more intelligent than humans. Hehas been awarded higher doctorates by both Imper-ial College and the Czech Academy of Sciences,Prague and has been described by Gillian Andersonof the X-Files as Britain’s leading prophet of therobot age.

11September 2002

Three of the Seven Dwarfs, a group of small robotsdesigned by Kevin and his team. Their electronicsmimic aspects of the human nervous system.

BOX 1 A MULTIDISCIPLINARY TEAM

The team working with Kevin has come togetherfrom different branches of cybernetics and neuro-surgery. Kevin Warwick specialises in artificialintelligence and robotics and Brian Andrews in biomedical engineering, neural prostheses andspinal injuries in the Department of Cybernetics atthe University of Reading. Peter Teddy has a longinvolvement with neural implants and is the Head ofNeurosurgery at the Radcliffe Infirmary in Oxford.

These three principal investigators lead a largeteam of surgeons and researchers including BrianGardner, Ali Jamous, Amjad Shad and Mark Gassonof the world famous National Spinal Injuries Centre(NSIC)-Stoke Mandeville Hospital.

Array connection to median nerve

Implant site

Fixed connector

Exit from skin

Radio signal

Detachable radio transceiver module

l Apart fromKevin’s own site,you can find outmore aboutcybernetics and theSeven Dwarfs at hisdepartment’s site:http://www.cyber.rdg.ac.uk/

l Longer articleshe has writtenrecently are at:http://www.wired.com/wired/archive/8.02/warwick.htmlandhttp://www.guardian.co.uk/Archive/Article/0,4273,3954989,00.html

Figure 1 Diagramshowing how theimplant works.

The implantsurgery inprogress.

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12 Catalyst

If you eat a packet of M&Ms you see the numberleft in the packet declining — and if you like par-ticular colours best those are likely to disappear

quicker! Measuring populations of birds in Britain isa bit more complicated. Birds move around duringthe year — some spend the winter in Africa — andlosses through death may be completely offset bynew birds hatching and growing up.

To get up-to-date figures, large numbers of volun-teer birdwatchers go out in the summer every yearand count the birds on over 2000 randomly-selectedplots in all sorts of habitats throughout the country.Each plot is 1 km2 of the National Grid.

COUNTING BIRDS

Every year the counts are made by the same peopleusing the same method at the same sites. They walk2 km in a straight line recording everything they seeor hear, once during the first half of the breedingseason and again during the second half. The resultsare compiled by the British Trust for Ornithology(BTO) and compared with those from the same sitethe previous year, to give an overall percentagechange from year to year (Box 1). If the change from

year to year is small or there are small numbers ofrecords it may not be statistically significant — inother words it could have happened by chance —but many are significant.

This Breeding Bird Survey (BBS) has been operat-ing since 1994 and has shown that, of 96 differentspecies with records from at least 30 plots, more (35species) had increased significantly than haddecreased (23 species).

The BBS replaced an earlier survey (Common BirdsCensus or CBC) that was more limited, covering

CHRIS MEAD

GCSE key wordsPopulation

Pesticides

Human impact onthe environment

Data collectionand analysis

BOX 1 COMPARING YEARS

The BTO surveys are designed to compare popula-tions from different years. One year is chosen as thebenchmark and given an index value of 100; allother years are indexed on that year. If 1998 was theindex year, with 500 birds and, in the same plots,there were 450 birds the next year (1999), the indexvalue for 1999 would be 90. If the number recordedin 1968 was 1000, the index value for that yearwould be 200, giving a percentage decrease from1968 to 1999 of 90/200 × 100 = 45%. Table 1 showsthese percentage changes.

Living things can act as biological indicators of problems in the way we are managing our

environment. Skylarks and other birds are disappearing from our farmland. How do we know

that this has happened, why have they declined and what can we do to encourage them back?

Chris Mead from the British Trust for Ornithology has some of the answers, which will be useful

when you look at human impacts on the environment in your GCSE science course.

Where have all the skylarks gone?

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fewer sample sites and species from fewer habitats.However, it had data across more than 35 years.

RESULTS

Table 1 shows all species where the populationhalved between 1968 and 1998. The percentagechange in the index is shown for this period for theCBC and for the BBS for the whole of the UK for1994–2000.

You can see detailed results for other species onthe British Trust for Ornithology website athttp://www.bto.org/birdtrends/ Other species are alsogiving great cause for concern. For instance the

lapwing population (also known as peewit, greenplover and a host of dialect names) in England fell by49% between 1987 and 1998.

There are several species where the reasons fordecline seem to be clear (see the boxes on this pageand overleaf), but detailed research needs to be doneto find out exactly why this has happened.

HOW AND WHY HAVE BIRDS DISAPPEARED?

Finding out that bird numbers have declined is onlythe first part of the detective work. Why has it hap-pened? What can we do to get them back?

13September 2002

GREY PARTRIDGE

The chicks must be able to find insects, like sawflylarvae, if they are to survive their first fortnight.These insects have become much rarer in the last 40 years. Chicks may also be killed by chilling in wetsummers, of which we have had many.

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100200300400500600700800

19701974

19781982

19861990

19941998

2002

Index (1998=100)

Year

Species Habitat* CBC change 1968–1998 (%) BBS change 1994–2000 (%)Tree sparrow F, W −95 +25Lesser redpoll S −90 +8**Grey partridge F −83 −22Corn bunting F −83 −35Spotted flycatcherS W, F −79 −21Tree pipitS W −77 +12**Woodcock W −70 Not calculatedStarling F −70 −5**Turtle doveS F −69 −24Willow tit S, W, F −66 −54Marsh tit S, W, F −66 +45Song thrush F, W, S −60 +12Linnet S, F −59 −6**WhitethroatS S, F −57 +26Yellowhammer F, S −54 −12 Skylark F −53 −8Bullfinch F, S −50 −25S Summer migrants.

* Major habitats are F = farmland, W = woodland and S = scrub.

** These figures are not statistically significant.

Table 1 Change in CBC index for selected species

Left: The greypartridge is foundon farmland andmoorland.C

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The governmentnow includes birdpopulations in the‘Feelgood Factor’indices publishedeach year.

In the long term questions like this can only beanswered by tackling far-reaching problems to dowith the countryside and the working of agriculture.

Many of the species listed in Table 1 live infarmland — some (like grey partridge and skylark)in the open fields, but most of them in and aroundhedges. Changes in agriculture over the past 40years have meant that fields have been drained,hedges removed, crops planted in autumn ratherthan spring and new pesticides introduced tocontrol insects, weeds and diseases. This reduces thenumber of animal species in the area. Pasture land ismown more frequently and is treated with muchgreater quantities of fertiliser, reducing the variety

of plants growing in it. Crop yields have beenincreased by these measures but little attention hasbeen given to the needs of wildlife.

FARMERS PROTECTING BIRDS

The European Union’s Common Agricultural Policyhas recently been changed and farmers will now bepaid to adopt practices that help wildlife and theenvironment. These include:• reducing the amounts of fertilisers and pesticides

used;• leaving 6-metre uncultivated strips round the edges

of fields for wildlife;

14 Catalyst

SONG THRUSH

Survival studies show that the young birds are morelikely to die, some time between fledging and thenext breeding season. Breeding season researchshows that there are fewer breeding attempts thanthere used to be, possibly because summers aredrier. In the last few years damp summers have ledto a slight recovery.

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TURTLE DOVE

Many pairs are breeding better now than they usedto (average 0.8 chicks rather than 0.6 per attempt).However they are breeding once a year instead oftwice so each pair only rears 0.8 of a chick ratherthan 1.2.

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400

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350

SKYLARK

Skylarks nest on the ground. Many crops are nowsown in the autumn for harvesting early the follow-ing summer. Such crops are too thick for birds tobreed in during the spring. Skylarks feed on seedswhich they obtain from the soil in bare winter fields.The seed ‘bank’ in the soil has been much reducedby use of herbicides and so their winter survival hasfallen. Setting land aside from cultivation and plant-ing crops in spring will help them recover.

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Pasture is grazingland. Some

permanent pasturemay have been

grazed forcenturies and has

great biodiversity,with wild flowers

amongst the grass,and many insects.

Above: A nestingsong thrush.

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• providing uncultivated areas across big fields, toact as beetle banks;

• ‘setting-aside’ areas, usually whole fields, whichare left uncultivated for a season or longer.

All this will take several years to come into effect.Farmers can also join schemes run by DEFRA

(Department of the Environment, Farming andRural Affairs) which are trying to preserve thespecial feel of an area like the Yorkshire Dales orthe East Anglian Brecklands, or simply helpingwildlife in ordinary farmland. They include thingslike careful management of hedges, planting offarm woodlands and conservation of smallwetlands.

15September 2002

l Species byspecies accountsfor all of Britain’sbreeding birdsfrom Chris Mead’sbook can be foundat http://birdcare.com/bin/searchsonb

Many beetles areuseful on farms,preying on croppests. Beetle banksprovide a space forthem to reproduce.

BOX 2 HOW BIRD POPULATIONSMIGHT DECLINE

Think about a pair of birds which normally has threebroods of young each year with an average of twochicks each. On average, one of the adults and oneof the chicks survives to breed the next year. Try outthe maths of the following scenarios:(1) Adult mortality increases and, on average, only

0.9 adults survive.(2) Juvenile mortality increases and, on average,

only 0.8 chicks survive.(3) Nest survival decreases and only one chick per

nest survives to breed.(4) The breeding season shortens and only two

nesting attempts can be made.See how long it takes for the species to decline by50%.

STARLING

Adults and young birds seem to be able to survive aswell as ever but the nestlings are at risk because theyare fed on soil invertebrates, like leatherjackets,whose numbers have been reduced by pesticides.

19660

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Answers to Birds puzzle, page 9T O U C A N T T D T T T T T T P L O V E RU T T R T T G O O S E T L T T U T W T T TR T T O T T T T V T T T A T T F A L C O NK T T W O O D P E C K E R T T F T T T T TE T T T T T T T T T I T K I W I T O T T FY T T T P H E A S A N T T T T N T S T T IT T T T A T T T T T G T T T T T T T E R NW A D E R T T S W I F T T D I V E R T T CR T T T A T T T T T I T T U T T T I T T HE T T T K T T I B I S T T C T T T C T T TN T B T E T C T T T H A W K T N T H T G TT T O T E M U T T T E T A T T I T T T R TT C O O T T C T P A R T R I D G E T T O TT T B T T T K T E T T T B T T H T T T U TJ A Y T S P O O N B I L L T T T H R U S HT T T T W T O T G T T T E T T J T T T E TT T S W A N T T U T T T R H E A T T T T TT T T T L T T T I T T T T E T R A I L T TT T P E L I C A N T S T O R K T T T T T TT T T T O T T U T T T T T O T T T T T T TM A C A W T T K T T G A N N E T T T T T T

Answer: not very long(1)14 years(2)7 years(3)3 years (4)4 yearsThese are the kind of changes that we suspect arehappening to some species or other: try seeingwhat happens with other scenarios.

BTO surveys will be worth watching over thenext few years to see whether the decline in some ofthe farmland bird populations described in thisarticle is reversed by more wildlife-friendly farming.

Chris Mead worked for the British Trust forOrnithology for over 33 years. He was mainly con-cerned with bird-ringing and has marked over300 000 birds in Britain, Spain, Portugal, Italy,Senegal, Zimbabwe, Malaysia and Belize. He stillcarries on bird-ringing and writes and broadcastsabout birds.

Left: Starlings areoften found ingardens and urbanareas but theirnumbers aredeclining.

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One winter day in the garden I noticed a flat-tened spot in the snow circled by a puff ofgrey pigeon feathers. There were no paw

prints in the snow to give a clue about the predator.I was mystified, but my father-in-law was not.‘Hawk strike!’ he muttered. He should know —sparrowhawks and other raptors are regular visitorsto his South Yorkshire pigeon loft, and from time totime they stoop on his birds on exercise flights.

Raptors such as peregrine falcons and sparrow-hawks feed on garden songbirds, other wild birds,grouse and pigeons. Though many bird species are declining through loss of habitat (see ‘Wherehave all the skylarks gone?’ on pages 12–15), bird ofprey numbers are increasing as a result of conserva-tion. Flocks of racing pigeons could be a good foodsource for raptors facing increased competition for

sustenance. Racing-pigeon owners are angry aboutthe large number of pigeons they believe are lost toraptors and would like to introduce controls onraptor numbers.

CONSERVATION VIEW

Some birds of prey became very rare in the 1960s aschanges in agricultural practice reduced their num-bers. Increasing field size and changes in crops andcultivation techniques reduced the numbers of thesmall birds and mammals they predated. Pesticidesaccumulating through the predator food chaineventually reached concentrations that affectedtheir reproduction. Gamekeepers shot or trappedbirds believed to take pheasants and grouse rearedfor shooting. It seemed possible that a significantsection of our wildlife would completely disappear.

Legislation was introduced to protect particularbirds of prey — it became illegal to shoot them,damage the nests, take them from the wild for fal-conry, or to collect and trade in birds’ eggs. Pesti-cides such as DDT that had harmful effects in thefood chain were restricted. Bird conservation bodiesprotected breeding pairs and raised public awarenessfor the cause. Captive-bred birds like the red kitewere reintroduced to areas where they had died out.As a result birds on the edge of extinction, such asperegrine falcons, have increased to secure numbers.

16 Catalyst

A gamekeeper issomeone who

looks after youngbirds bred for

shooting in fieldsports. Preventing

predation is part ofthe job.

A raptor is a termto describe birds ofprey which pounce

on their prey.

Stoopingdescribes the waya falcon dives on

its prey fromabove.

F O Rd e b a t e

GCSE key wordsConservation

Human impact onthe environment

Accumulation

Predator

Should predators be preserved?Pigeons or peregrines?

Right: A champion racingpigeon. The lighter-colouredbirds seem to be morevulnerable to attack.

Below: A peregrine falcon.These birds were on the edgeof extinction before they wereprotected. Are they now toomuch of a threat?

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PIGEON-FANCIER’S VIEW

Numbers of many garden birds are declining dra-matically and increasing numbers of racing pigeonsare going missing during races and training flights,including experienced birds which are less likely toget lost. Pigeon owners blame raptors. When aperegrine falcon stoops on a flock of pigeons thebirds disperse in all directions to escape. The falconmay take one bird but others are lost as they fly offin different directions for some time, go to groundor take refuge in trees, perhaps staying overnight,short of food. Scared pigeons may take up withwild flocks of pigeons.

Racing pigeons are ringed with an identificationnumber, and pigeon fanciers claim that hundreds ofrings have been found in areas where raptors areestablished. Races passing through areas whereraptors have been successfully conserved are at highrisk. Where predators live near traditional racerelease points they are attracted by the circlingflocks of pigeons seeking direction. Pigeons strug-gle home with bloody feathers and torn fleshhaving survived raptor attacks, and pigeon ownersare as fond of their pigeons as you are of your pets.There is an economic loss too. Pigeons can be veryvaluable, changing hands for thousands of pounds,apart from the prize money.

What can the fancier do? Some are experiment-ing by using dark-coloured birds for better camou-flage. Some argue they should stop racing for twoseasons — if raptor numbers fall it suggests thatthey need pigeons to survive. There may be otherreasons for reduced pigeon numbers — perhapspigeon breeders selecting for speed and homingability have accidentally been breeding more stupidpigeons over the last few years, or maybe theincrease in electrical appliances and power cables isupsetting the birds’ magnetic navigation system.

17September 2002

One studyestimated that 50breeding pairs ofperegrines in theSouth Walesvalleys will killalmost 12 000racing pigeonseach year. Howcould an estimatelike this bechecked?

l If you find apigeon with a ring,or just the ring,contact the RoyalPigeon RacingAssociation athttp://www.rpra.org

l Visit the RSPBwebsitehttp://www.rspb.organd search for‘pigeons’; orSongBird Survival athttp://www.songbird-survival.org.uk fordiffering views onprotection of birdsof prey.

A racing pigeon killed by a raptor.

THE ISSUE

All over Europe projects are underway to encouragediversity and return species to the wild in regionswhere they have died out. In the Jura region ofFrance, captive-bred lynx are being released, whileelsewhere bears and wolves are protected. Returningwolves to the wild in Scotland has even been dis-cussed. But is this automatically ‘a good thing’? Avalid argument against the reintroduction of beaversin Scotland is that ecosystems have found a newbalance since they died out 300 years ago. Thisbalance would be disrupted if beavers were returned.

What about the balance in your locality: foxes,kestrels and grey squirrels thrive in our urban envi-ronments? Would you want to see it changed? Farmore species have died out and been replaced duringthe Earth’s history than are alive now: what is theevolutionary view? How would you feel if a preda-tor were introduced to your area and your petscouldn’t go out without the risk of being eaten?Farmers are also not keen to see the return of preda-tors and would require compensation for losses.

What do you think?

Jane Taylor teaches biology and is an editor of CATALYST.

Birds of prey living in places where races start are a particular threat.

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The Earth Centre opened in 1999, its construc-tion transforming the badly scarred andpolluted land that had been the site of two coal

mines. Its unusual buildings, exhibitions, demonstra-tions and lovely gardens invite visitors of all ages todiscover the idea and reality of enjoying a better qual-ity of life without harming other people or theenvironment.

Over the last 3 years the Earth Centre has wel-comed educational groups from all parts of the UK,as well as overseas parties from mainland Europeand North America. A science day here might seeyou doing any of the following:• investigating energy with a journey from fossil

fuels to renewable energy possibilities; • building and experimenting with our ‘solar buggies’;• expending some energy with your friends riding on

our seven-seater circular bike;• investigating our energy-efficient buildings and

devices;• looking at food chains and webs by actually build-

ing your own live food chain in a jar;• becoming a drop of water and experiencing the

water cycle in our ‘white knuckle’ simulator ride;• watching sewage being digested in our tropical

greenhouse and seeing how we reduce the problemof eutrophication with our ‘bio-fence’.

18 Catalyst

Many of the topics you study as part of your GCSE science course,

for example, global warming, acid rain or resource depletion,

tend to be presented as huge problems we as individuals are

powerless to do anything about. The Earth Centre near Doncaster

is a unique and imaginative hands-on visitor attraction which

demonstrates that we can do something.

P L A C E St o v i s i t

VISITING THE CENTRE

The Earth Centre is in South Yorkshire, betweenSheffield and Doncaster, at Conisbrough (see Figure1). It is signposted from the motorways if you aretravelling by car, or you can take on board the EarthCentre’s sustainability message and travel by localbus from Sheffield, Rotherham or Doncaster.

If you are walking or cycling the Trans-Penninetrail you will pass right by the centre, and if you areon a narrowboat holiday you can tie up at the EarthCentre’s wharf for a visit — although you must ringfirst for a mooring. The wharf is also used for tripsdown the River Don from the centre.

The centre holds cycle events from time to time,with some weird and wonderful bikes. Cycles areimportant in managing the centre — they are used bythe staff to get about and do things like emptying thebins.

Centre

Above: Our energy-efficient

conference centre.Right: Climbing is

one of the activitiesavailable at the

centre.

A DAY VISIT…

The centre is open between 10 a.m. and 4 p.m.,longer in the summer, with short tours availableduring the middle part of the day for an extrapayment. Tokens are needed to pay for some activi-ties and rides and these can be bought separately oras a package with the entrance fee. Activities includecanoeing, climbing, abseiling, zip-wiring, archery,team-building and mountain biking.

Admission charges are:Adults: £4.50Under 16s: £3.50Under 5s: freeFamily tickets are also available

…OR COME AND STAY

Because there is so much to do in one day, last yearthe centre introduced a residential package with adifference. Students stay in luxurious en-suite accom-modation, and experience workshops and the widerange of adventure activities listed above to create atruly dynamic experience. There is a well-equippedcomputer suite, and digital cameras are provided todocument your discoveries.

If you would like to find out more about the widerange of activities available at the Earth Centre, visithttp://www.earthcentre.org.uk

Steve Bowles is Education Manager at the EarthCentre. Before taking up this post he was Head ofScience at a secondary school.

19September 2002

Teachers canrequest a schools’pack bytelephoning thebookings team on01709 513944.

BOX 1

Sustainability is the main focus at the Earth Centre— at the heart of its construction as well as its activ-ities. This region of South Yorkshire was oncefamous for its steel industry, coal mining and metalsmelting so restoring the site involved land remedi-ation and reclamation. Soil was made using amixture of organic materials: sewage sludge, farmmanure, mushroom farming waste and other sortsof green manures. Recycled wood and steel wereused to build the structures.

Visitor wastes are recycled or composted. Thelandscape was designed to recreate natural habitatsthat encourage repopulation by native species of animals, such as the grey partridge (see page 13), andplants. The woodland is managed for sustainability.

Station

Doncaster

Rotherham

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Sheffield

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Figure 1 Map showing howto get to the Earth Centre.

Far left: The EarthCentre with theRiver Don in the foreground. Left: Natureworks.

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Chemical engineers help in the manufacture ofproducts and components of products thathave an impact on all our lives. They develop

the processes that create fuels to power our industry,homes and cars. They develop dyes and specialistfabrics for the clothes and shoes we wear.

They even developed the process by whichmicrochips are made for mobile phones. These startlife as grains of sand, and chemicals, gas and goldhave to be added under the right conditions and atthe right time in the process to make the chip. Theproducts of chemical engineering are all around you.

SAVING LIVES

Usually we think of doctors, paramedics and nursesas the people who save lives, but chemical and bio-chemical engineers are also involved in developingthe drugs and treatments that modern medicinedepends upon. For example, they are currently

working on ways of growing replacement body partsfor transplant, including healthy bone marrow fortreating conditions such as non-Hodgkin’s lym-phoma and leukaemia, as well as advancing radiog-raphy treatments for cancer.

The case studies in Boxes 1 and 2 give an insightinto what a career in chemical engineering is like.

SKILLS AND INTERESTS

Chemical engineers often work as part of a team,and are required to have good social skills. Theyface stiff challenges that demand excellent problem-solving and analytical skills, plus a dose of imagina-tion. Chemical engineers are also highly IT-literate,as much of their work uses computers.

REWARDS

Chemical engineers earn, on average, more than similarly qualified accountants, chemists, softwareengineers and architects. In addition to the highfinancial rewards, chemical engineers are regarded as

20 Catalyst

Y O U Rf u t u r e

Chemical engineeringDo you have a mobile phone? Do you wear

trainers? Do you use hair wax or gel? All these

products depend on chemical engineering.

And here is something else that may surprise

you — chemical engineers also save lives.

BOX 1 SUSHIL ABRAHAM, LONZABIOLOGICS, NEW HAMPSHIRE, USA

Biotechnology is a really fast-growing sector that ismaking huge developments all the time. Choosingto study biochemical engineering was one of thebest decisions I ever made — it’s extremely dynamicand the job prospects are fantastic.

At the moment I’m working in the States forLonza Biologics. I develop processes that happen inthe laboratory into large-scale manufacturing. Thismeans working out what the processes are, andwhat machinery will be needed to achieve the fin-ished pharmaceutical product.

I deal with lots of people on a daily basis— every-one from scientists to suppliers, which keeps meup-to-date with the latest developments. I reallyenjoy being able to work in a team, which is just asimportant as being able to manage and superviseother staff.

My job is challenging and the rewards are excel-lent. I know that I’m contributing to society byproviding badly-needed drugs and treatment. Howmany other people get to see their project throughfrom start to finish?

ICh

emE

professional ‘high flyers’, and have the potential togain Chartered Chemical Engineer status.

HOW TO QUALIFY

The preferred route to becoming a chemical engineeris to gain a degree accredited by the Institution ofChemical Engineers. Ideally, you need to considerMEng chemical engineering degree programmes.

To be accepted on an accredited degree course,you will need good GCSE results and A-levels inmathematics and chemistry, with physics if you wantto study chemical engineering, or with biology to

study biochemical engineering. There are some alter-native routes and you should approach universitiesfor further information.

ONE DEGREE, MANY CAREERS

Chemical engineering is a well-respected degree thatopens many career paths. Many graduates areattracted by highly-paid jobs in the City and thebank HSBC is the biggest employer of chemical engi-neers. Employers appreciate that graduates of chem-ical engineering have analytical and problem-solvingskills that are second to none. Careers within chem-ical engineering are equally diverse — industries youcould work in include: food and drink, oil and gas,pharmaceuticals and tissue engineering.

FURTHER INFORMATION

http://www.whynotchemeng.com carries more infor-mation about chemical engineering and case studiesof real-life chemical engineers. It also links to thewebsites of all UK universities offering accreditedchemical engineering degree courses, and a sample ofmajor industrial employers.

Information packs are available from: The Insti-tution of Chemical Engineers, Davis Building,165–189 Railway Terrace, Rugby, CV21 3HQ, tel. 01788 578214.

Louise Robinson works for the Institute of Chemi-cal Engineers where she is Marketing Executive andProject Leader for whynotchemeng website.

21September 2002

An aspect ofchemicalengineering isfeatured on theback page — a rigwhich wasdesigned and builtpurely for teachingpurposes. If youwere to take thechemicalengineering courseat SurreyUniversity youwould learn byexperience on this rig.

BOX 2 PHIL SOUTHERDEN, BP CHEMICALS, LONDON, UK

When I was at school I had no firm idea about whatI wanted to do as a career so I chose chemical engi-neering to keep my options open.

I have worked both in the UK and abroad andhave constantly been faced with new developmentopportunities and challenges as I moved from pro-ject to project.

The highlight, so far, has been working as themain process engineer on a BP site in Indonesia to fitthe first large-scale operation of the next generationof catalyst to their existing plant, which was a greatsuccess.

My job involves travel, meeting people and givesme a huge amount of independence and responsi-bility.

The photographsshow students onchemicalengineering coursesgetting hands-onexperience ofmonitoringprocesses.

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Polishing filter

Heat exchanger

Main process filter Pump 1

Pump 2

Reactor vessel with heating coil and agitator

Product tank

Feed water

Waste carbon dioxide to scrubbing unit

Solid feed hopper NaCl, CaCl2,and NaHCO3

Immersion heater 1

Immersion heater 2

Heating vessel

This rig includes many features ofa larger-scale chemical works,

such as control of feed materials toreactions, a reactor vessel and allsorts of monitoring and controlsystems. It is used to train people atmany different levels, includingprospective chemical weaponsinspectors for the United Nations.

The rig itself produces a highly pure sodium ion solutionwhich could have applications in the electronics andpharmaceuticals industries, among others.

The feedstocks to the process are rock salt (solid sodiumchloride with a small percentage of calcium chloride

The reactor vessel.

All thereactions takeplace in thisheated reactorvessel. It has anagitator(stirrer) to aidmixing

Carbon dioxideis removed from the gasstream by the carbondioxidescrubber so it isnot released tothe atmosphere

The pump circulates theliquid exiting the reactorvessel

The finishedproduct collectsin the producttank

The heatingvessel containstwo electricheaters whichheat the watercirculatedaround thereactor vesselto control itstemperature

The solid feedhopper has ascrew feederwhich can beturned at dif-ferent speedsto control therate of solidfeed to theprocess

In the heatexchanger thefeed water ispreheatedusing heatfrom theproduct stream

The solid calcium carbonate thatprecipitates out is removed bythe main process filter

The rig.

Chemical plant

l Match the components in thediagram with the photograph of therig.

contaminant), sodium bicarbonate and water. These feedstocksreact together in the reactor vessel, according to the processchemistry below, and the precipitated contaminant is removedfrom the solution by filters. A high-quality sodium and chlorideion solution is produced.

PROCESS CHEMISTRY

The sodium bicarbonate thermallydecomposes:2NaHCO3(aq) →

Na2CO3(aq) + H2O(l) + CO2(g)

The sodium carbonate then reacts with thecalcium chloride contamination in the feed:Na2CO3(aq) + CaCl2(aq) →

2NaCl(aq) + CaCO3(s)

The solid calcium carbonate can then beremoved from the system by the filter,leaving a pure salt water solution asrequired.