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LISTENING SCRIPTS

Part I. Materials science and machine tools

Unit 1. Mechanical Engineering

CD Tape-1. MECHANICAL ENGINEERS ALSO DESIGN TOOLS

Interviewer: Different fields of engineering often overlap. Which engineering disciplines are more closely related to mechanical engineering?

Engineer 1: There are a number of fields, including electrical engineering, civil engineering, industrial engineering, systems engineering, aerospace engineering, and nuclear engineering.

Interviewer: How would you define mechanical engineering? That is, what is the nature of the work?

Engineer 2: As mechanical engineers, we research, develop, design, manufacture, and test all sorts of tools, machines, engines, and other mechanical devices. I should mention that mechanical engineers also design tools that other engineers need for their work.

Interviewer: What are the basic theoretical subjects that a mechanical engineer has to be conversant with?

Engineer 3: There are many things… I would say that the basic areas of knowledge are dynamics, statics, solid mechanics, strength of materials, fluid dynamics, thermodynamics, heat transfer, kinematics, mechatronics…

Interviewer: What sort of things do mechanical engineers actually make?

Engineer 4: Well, the list is almost endless. Mechanical engineers make machines for producing power — things like electric generators, steam or gas turbines — and different types of internal combustion engines. They also make machines that use power — things like air conditioning and refrigeration equipment, machine tools, elevators and escalators, even robots…

Part II. Metals

Unit 4. Steel

CD Tape-2. SHAPE MEMORY ALLOYS

Shape memory alloys have many applications, but before I give some examples, what exactly is a shape memory alloy?

Essentially it’s a metal which can be deformed when cold and will remember its original shape when heated. The particular alloy we are using here in the lab is nickel titanium.

We can see one application here in a conventional piston. When the piston is cold, the SMA coil or spring contracts and so the piston doesn’t move. Heat causes it to expand and consequently the piston moves up. The advantage is that the device can work without any mechanical power, just from the heat which is supplied by the engine itself.

Let’s look at some other applications. Over here, we have a domestic coffee machine. We’ve fitted a valve controlled by an SMA actuator. When the coffee machine reaches a certain temperature, the SMA actuator opens the valve and so the water is dumped onto the coffee. Again the system works without any additional power — electrical or mechanical — just the heat of the steam given off as the water heats up.

One more application — this time for the motor industry. We’re experimenting with a spring device which expands when it cools. The device will be fitted to the cooling fan. In cold weather the spring expands and this makes the fan close down, and thus helps to warm up the car. In warm weather, the spring contracts and therefore causes the fan to operate and a result helps to cool down the car. Again a system using no external or additional power source. Right, are there any other questions?

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Part III. Plastics

Unit 2. Types of plastics (Part I)

CD Tape-3. THE HISTORY AND PROPERTIES OF PLASTICS

A=Antonia, F=Fatima

A: I think that this assignment on the history and properties of plastics should be quite interesting.

F: Yeah, I’m looking at the British Plastics Federation website that is www.bpf.co.uk, it’s got some good stuff about the history of plastics. You know plastics can be used to produce almost anything nowadays.

A: Yes. Just look at your toothbrush, these files, the table lamp, the street lights outside, even the white lines on the road; they’re all made of plastic.

F: It says here that the first plastic was made of cellulose in the mid-eighteen hundreds and was used to make billiard balls! That was a great step forward in the world of science. Apparently, people were worried that there weren’t enough elephants to provide ivory for making billiard balls so they had to find a substitute. The first balls were made of coated celluloid.

A: Celluloid is the plastic made from cellulose, isn’t it?

F: Yes, and cellulose comes from plants. The problem was that this can be explosive. The inventor liked to tell stories of the early balls exploding when they were hit hard! Imagine that!

A: I found a book in the college library called Plastics, and it says that another problem with the early plastics such as celluloid was that you couldn’t make things to a high standard of quality. Apparently, it wasn’t until they started using petroleum and natural gas in the midnineteen hundreds that plastics production was really able to take off!

F: Yes, it says here that using petroleum and natural gas led to the development of so many different plastics: polyethylene, nylon, polyester, and they’ve all got different properties so you can always find one that’s suitable for your product.

A: Exactly! They’re really versatile. Today, the plastics industry is mainly based on oil so we can produce household and industrial items cheaply. But we are running out of oil, what are we going to do then?

F: Recycle! On this website, www.chemsoc.org there are loads of facts about plastics. Today manufacturers have the technology to produce things such as rubbish bins, plastic sacks, and even clothes from recycled plastic and I’m sure we’ll be able to extend this range of goods soon. I’m sure we’ll be recycling large quantities of plastic in the future. But we’ll have to find good systems for collecting plastic for recycling. That’s not very effective at the moment.

A: We’ll also have to find alternative raw materials for producing new plastic. There are already new technologies available which allow us to use other raw materials.

F: Yeah, look! I’ve just found in www.wordcentric.org that companies are now able to make bioplastics from the starch in wheat, and even oranges! Some manufacturers are already producing things like food wrapping from these bioplastics.

A: I think they are still expensive to produce, so more research will have to be done to allow us to produce these plastics more cheaply. But I’m sure that these will be important for the future for plastics.

Part IV. Automobile

Unit 5. Driver, Vehicle, and Road

CD Tape-4. THE MOST UNPOPULAR MEN IN LONDON

It’s half past eight in the morning and John Punch is starting his day’s work. Before he finishes, he and his mate, Dave Wilson, will be shouted at, argued with and sworn at. But that’s all in a day’s work for two of the most unpopular men in London. For John and Dave are a

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tow-away team. With their blue and white lorry they lift cars that have been illegally parked and take them away to the car pound.

Like most European cities London wasn’t built for cars, but every day millions of motorists enter the city and look for somewhere to park. But there simply isn’t enough parking space and so about half a million vehicles a day are parked where they shouldn’t be. On double yellow lines, on bends, on crossings, or just double parked. If one of these vehicles is seen by a traffic warden or a police officer a yellow sticker is placed on a windscreen. Any car with a yellow sticker can be towed away by any tow-away team that finds it and they don’t waste their time.

Within three minutes the vehicles are lifted onto the lorry and it’s on their way to the pound. If the owner arrives before the car has been lifted they are allowed to drive it away. But once it’s off the ground it’s too late. As John explains:

“Oh, no. Once we’ve lifted the car, we won’t put it down again. Well, if it’s a pregnant woman or a mother with lots of kids the car might be dropped. But we probably take it round the corner first so nobody would say. But normally we won’t put it down. Once it’s off the ground it’s off to the pound”.

At the pound a fee of £101 must be paid to get the car back again. And there is another £12 for every day that the car is left in the pound. And motorists don’t like that at all. Here is John again.

“People get very annoyed if they see us when we’re lifting their car. Most of them shout and scream at us and call us names. Other scribes the sob stories. You won’t believe some of them. One woman came out of the flower shop with a big bunch of roses. She told us that her old cramped mother was dying and her last wish was to see some red roses. Then we looked at the car and at roses and it said: “Happy anniversary, darling”.

And a lot of motorists try bribery. But it won’t work.

“No we never accept the bribe. It won’t be worth it. We’d lose our job immediately if anyone found out. A fifty clod bribes is no good if you lose your job for it”.

The tow-away men tell of one motorist who offered over one thousand pounds to a team. The police found that the car was full of drugs.

How do the tow-away men feel about being so unpopular?

“It’s used to upset me when I first started but now I don’t hip at this. Anyway we think we’re doing an important job. Cars shouldn’t be parked on bends and places like there. It’s dangerous. We’re that cases where far engines couldn’t get further emergencies because cars have been double-parked.

No, without us London would just stop and even more people would be annoyed then”.

Part V. Robots and computers

Unit 1. Machines through the Ages

CD Tape-5. IT’S MY JOB

I = Interviewer, J = Jaako Ikonen

I: How did you get interested in technology?

J: I started making radio-controlled model boats at the age of 13. I: That’s how you got started?

J: That’s how I got started, yeah. I loved playing around with the electronics. I: Did you go on college at the end of school?

J: Yes, I went to college and did Mechanical engineering with one year of Electrical and electronic engineering.

I: What was your first job?

J: Designing and building automated manufacturing systems for a mobile phone company. They needed to automate because production was going through the roof, their old system simply could not produce enough phones.

I: I’m not clear about the distinction between mechanization and automation.

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J: Big difference. Mechanization is the old world of machines with no brains, they could do only one thing — like Henry Ford’s assembly lines. Automation means you are using a combination of software, of mechanical engineering, electronics, electrical engineering — that’s the mechatronics side of things. There’s intelligence built in. That’s why it’s called automation.

I: You then moved to your current job?

J: Yes. I’m Senior Manufacturing Systems Engineer for a large health care company. That means I’m responsible for developing all new processes and process automation for manufacturing our products.

I: What do you make?

J: One of the main products is blood glucose monitors for diabetics. It uses biosensors, which are coated in enzymes to measure the blood glucose levels in a drop of blood. Basically how much sugar there is in the blood.

I: Where does automation come in?

J: You can’t make these machines by hand. There can’t be any contamination, they have to be perfectly clean, and there can’t be any defects in the production. Peoples’ lives are involved so you cannot afford to be wrong. Also the volume is huge so only machines can achieve this.

I: Is it done by robots?

J: We use incredibly fast, vision-driven robots. They don’t simply pick up and place components blindly. They can see what they are doing, they can teach themselves, and they check every move they make to ensure there are no errors.

I: What qualities do you need to be successful in your field?

J: You must be innovative. You must be able to work across functions and be able to communicate with non-technical people.

I: Can you give me any examples of communicating with non-technical people?

J: I work in R&D and we have to constantly communicate with Marketing — they know what the customers want. We just have the ideas.

I: They seem to be great ideas. Thanks very much for your time. J: A pleasure, thank you.

Unit 3. Industrial Robots

CD Tape-6. PROBLEM SOLVING

I am going to tell you about the five sensors that our domestic robot vacuum cleaner contains. These sensors help it to navigate safely and to clean surfaces effectively.

The dimension sensors determine the size of the room. The robot cleaner sends an infrared signal in each direction in turn. These reflect from the walls and return to an infrared receiver. The processor calculates the dimensions of the room from the time taken for the signal to return.

Then there are object sensors — when the cleaner hits an object, such as a chair, the bumper, which goes right round the cleaner, is pressed in. This activates mechanical object sensors. These send signals to the processor which cause the cleaner to change direction to avoid the object.

There are also cliff sensors — under the cleaner there are infrared sensors directed downwards. If the time taken for the return infrared signal increases suddenly, the processor detects a ‘cliff’, for example, stairs or other sudden drops which the robot to reverse away from the cliff.

The wall sensors let the cleaner follow walls and go round objects closely but without touching them.

And finally, and most importantly, dirt sensors — these are acoustic impact sensors. When the cleaner raises a lot of dirt from a carpet or other surface, some of the dirt hits the metal place of the acoustic impact sensors. This causes vibration which the sensors detect. They pass a signal to the processor which causes the robot to clean the area again until there are no more vibrations — in other words, until the area is clean.

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Part VI. Graphs

Unit 2. Describing Graphs

CD Tape-7.deSCRIBING A PIE CHART

I’d like to show you a pie chart which represents the use of plastics by sector. If we take a look, we can see that the largest sector which uses plastic is the packaging industry. You will notice that over a third of all plastics are used here.

As you can see, the building and construction sector is the second biggest, using 23 per cent. You will notice that together with packaging, more than half of all plastics consumption is in these two sectors. Take a look at the electrical and electronics industry, which consumes eight per cent, and you will see that the same figure applies to the furniture and houseware sector, as well as the transport sector. Agriculture accounts for slightly less plastics consumption, seven percent.

At the opposite end of the scale from packaging, you can see that the smallest sector is the footwear sector, using only one per cent. Both the medical and mechanical engineering sectors use slightly more plastic than footwear — two per cent, while the toys and sports sector accounts for one per cent more than this.

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Glossary of Engineering Terms and Abbreviations

The definitions in this glossary refer to words only as they are used in this tutorial. The meanings of certain words will vary according to context. As the texts in this tutorial are authentic and come from a variety of sources, some inconsistency in hyphenation and spelling is inevitable.

Abbreviations used in the texts kg/m3= kilogram per cubic meter kph = kilometers per hour

MN/m2 = meganewton per square meter psi = pound on square inch

Brit = Britain

Us = United States

Fig. = figure

n = noun v = verb

adj = adjective adv = adverb para = paragraph

phrv = phrasal verb pl = plural

A

acceleration n — a vehicle's capacity to gain speed

adhesion n — the action or process of adhering to a surface or object

alloy n — a metal made by combining two or more metallic elements, especially to give greater strength or resistance to corrosion

alkali n — a compound with particular chemical properties including turning litmus blue and neutralizing or effervescing with acids; typically, a caustic or corrosive substance of this kind such as lime or soda

anneal v — heat (metal or glass) and allow it to cool slowly, in order to remove internal stresses

automation n — the use or introduction of automatic equipment in a manufacturing or other process or facility automobile n (Us) — a road vehicle, typically with four wheels, powered by an internal combustion engine or electric motor and able to carry a small number of people

B

bar n — a long rigid piece of wood, metal, or similar material

bar chart n — a graph which uses parallel rectangular shapes to represent changes in the size, value, or rate of something or to compare the amount of something relating to a number of different countries or groups bearing n — a support, guide, or locating piece for a rotating or reciprocating mechanical part

bend v — shape or force (something straight) into a curve or angle billet n — a small bar of metal for further processing

body n — the main section of a motor vehicle or aircraft

brake n, v — a device for slowing or stopping a moving vehicle, typically by applying pressure to the wheels; to make a moving vehicle slow down or stop by using a brake

breach n — a crack, break, or rupture brittle adj — hard but liable to break easily bug n — a mistake in a computer system

C

cam n — a specially profiled part which is fitted to a rotating shaft to produce linear motion

capacitor n — a device used to store an electric charge, consisting of one or more pairs of conductors separated by an insulator

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car n — also see motorcar, automobile — a self-propelled road vehicle designed to carry passengers, esp. one with four wheels that is powered by an internal-combustion engine

cast v — shape (metal or other material) by pouring it into a mould while molten

cellulose n — a polysaccharide consisting of long unbranched chains of linked glucose units: the main constituent of plant cell walls and used in making paper, rayon, and film

chassis n — the base frame of a car, carriage, or other wheeled vehicle

chisel n — a hand tool for working wood, consisting of a flat steel blade with a cutting edge attached to a handle of wood, plastic, etc.

chuck n — a device for holding a workpiece in a lathe or a tool in a drill, typically having three or four jaws that move radially in and out

circuit n — a system of electrical conductors and components forming an electrical circuit circumference n — the enclosing boundary of a curved geometric figure, especially a circle

clamp n — a mechanical device with movable jaws with which an object can be secured to a bench or with which two objects may be secured together

clutch n — a mechanism for connecting and disconnecting an engine and the transmission system in a vehicle, or the working parts of any machine

coating n — a thin layer or covering of something

combustion chamber n — an enclosed space in which combustion takes place, especially in an engine or furnace

composition n — the nature of something's ingredients or constituents; the way in which a whole or mixture is made up

compression n — the effect of forces which act to squash a structure

computer n -an electronic device which is capable of receiving information (data) in a particular form and of performing a sequence of operations in accordance with a predetermined but variable set of procedural instructions (program) to produce a result in the form of information or signals

consumption n — the amount of fuel or natural resources that is used or the act of using them

corrosion n — a process in which a solid, esp. a metal, is eaten away and changed by a chemical action, as in the oxidation of iron in the presence of water by an electrolytic process

corrosion-resistant adj — describes a material which can be used in environments where long term strength or appearance is important

creep n — the gradual deformation of a plastic solid under stress

crevice corrosion n — corrosion in cracks or crevices in pipes carrying liquids cutter n — a tool that is used for cutting through something

D

data n — a series of observations, measurements, or facts; information

decompose v — break down (organic matter) or (of organic matter) to be broken down physically and chemically by bacterial or fungal action; rot

density n — the quantity of mass per unit volume of a substance dependable adj — trustworthy and reliable

detect v — discover or identify the presence or existence of

dimension n — a measurable extent of a particular kind, such as length, breadth, depth, or height die n — a device for cutting or moulding metal into a particular shape

diesel engine n — an internal combustion engine in which oil is burnt by very hot air

differential n — a gear allowing a vehicle's driven wheels to revolve at different speeds in cornering

disc n — an information storage device for a computer in the shape of a round flat plate which can be rotated to give access to all parts of the surface

dismantle v — separate a machine or structure into different parts download v — copy (data) from one computer system to another or to a disk

drawplate n — a plate used to reduce the diameter of wire by drawing it through conical holes ductile adj — (of a metal) able to be drawn out into a thin wire

E

edge n — the outside limit of an object, area, or surface

efficiency n — the quality or state of being efficient; competence; effectiveness

elastic limit n — the point at which a material will no longer return to its original shape after tensile forces are released

eliminate v — completely remove or get rid of (something)

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engine n — any machine designed to convert energy, esp. heat energy, into mechanical work environment n — the surroundings or conditions in which a person, animal, or plant lives or operates error n — a mistake or inaccuracy

escalator n — moving stairs

exhaust n — waste gases or air expelled from an engine, turbine, or other machine in the course of its operation

F

fabric n — cloth produced by weaving or knitting textile fibres

faceplate n — a perforated circular metal plate that can be attached to the headstock of a lathe in order to hold flat or irregularly shaped workpieces

facility n — space or equipment necessary for doing something

factory n — a building or group of buildings where goods are manufactured or assembled chiefly by machine failure n — the act or an instance of failing

fatigue n — weakness in metal or other materials caused by repeated variations of stress

feedback n — information about reactions to a product, a person's performance of a task, etc. which is used as a basis for improvement

fender n — the part of a car body that surrounds the wheels

fibre n — a natural or synthetic filament that may be spun into yarn, such as cotton or nylon

file n — a tool with a roughened surface or surfaces, typically of steel, used for smoothing or shaping a hard material

film n — a thin flexible strip of plastic

final drive n — the last part of the transmission system in a motor vehicle flat adj — having a broad level surface but little height or depth; shallow flaw n — a mistake or shortcoming

flax n — a plant with blue flowers. Its stem is used for making thread, rope, and cloth, and its seeds are used for making linseed oil

flex v — bend or become bent

fluid n — a substance that has no fixed shape and yields easily to external pressure; a gas or a liquid

flywheel n — a heavy revolving wheel in a machine which is used to increase the machine's momentum and thereby provide greater stability or a reserve of available power

fibreglass n — plastic strengthened with short, thin threads of glass

foam n — a mass of small bubbles formed on or in liquid, typically by agitation or fermentation fracture n — the cracking or breaking of a hard object or material

fuel n — any substance burned as a source of heat or power, such as coal or petrol

G

gasoline n — petrol

gear n — (often gears) a toothed wheel that works with others to alter the relation between the speed of a driving mechanism (such as the engine of a vehicle) and the speed of the driven parts (the wheels)

gearbox n — a set of gears with its casing, especially in a motor vehicle; the transmission gradient n — an inclined part of a road or railway; a slope

grain n — a discrete particle or crystal in a metal, igneous rock, etc. , typically visible only when a surface is magnified

graph n — a diagram showing the relation between variable quantities, typically of two variables, each measured along one of a pair of axes at right angles

groove n — a long, narrow cut or depression in a hard material

H

hardening n — the act or process of becoming or making hard

hardware n — the machines, wiring, and other physical components of a computer or other electronic system head-on adj — with or involving the front of a vehicle

headstock n- the part of a machine that supports and transmits the drive to the chuck

hemp n — the fibre of the cannabis plant, extracted from the stem and used to make rope, strong fabrics, fiberboard, and paper

hood n — the bonnet of a motor vehicle

humidity n — the state or quality of being humid; a quantity representing the amount of water vapor in the atmosphere or in a gas

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O

obstacle n — a thing that blocks one's way or prevents or hinders progress orifice n — an opening, as of a pipe or tube

oscillate v — move or swing back and forth in a regular rhythm

output n — the power, energy, or other results supplied by a device or system oxide n — any compound of oxygen with another element

P

page n — a section of stored data, especially that which can be displayed on a screen at one time

peg n — a short pin or bolt, typically tapered at one end, that is used for securing something in place, hanging things on, or marking a position

pendulum n — a weight hung from a fixed point so that it can swing freely, especially a rod with a weight at the end that regulates the mechanism of a clock

performance n — the capabilities of a machine, product, or vehicle

petrol (gasoline) engine n — an internal-combustion engine that uses petrol as fuel

pie chart n — a type of graph in which a circle is divided into sectors that each represent a proportion of the whole piston n — a cylinder or metal disc that is part of an engine

pitting n — corrosion due to localized chemical reaction

plane n — a flat surface on which a straight line joining any two points on it would wholly lie

plasticizer n — a substance (typically a solvent) added to a synthetic resin to produce or promote plasticity and flexibility and to reduce brittleness

polyester n — a synthetic resin in which the polymer units are linked by ester groups, used chiefly to make synthetic textile fibres

polymerization n — the act or process of forming a polymer or copolymer, esp. a chemical reaction in which a polymer is formed

porosity n — the state or condition of being porous process v — operate on (data) by means of a program

propeller shaft n — a shaft transmitting power from an engine to a propeller or to the wheels of a motor vehicle property n — a quality, attribute, or distinctive feature of anything, esp. a characteristic attribute such as the density or strength of a material

punch v, n — press (a button or key on a machine); a device or machine for making holes in materials such as paper, leather, or metal

pump n — a mechanical device using suction or pressure to raise or move liquids, compress gases, or force air into inflatable objects such as tyres

R

raw material n — the basic material from which a product is made reciprocate v — move backward and forward in a straight line

recognize v — identify (someone or something) from having encountered them before; know again remotely adv — from a distance; without physical contact

rigid adj — unable to bend or be forced out of shape; not flexible

rivet n — a short metal pin or bolt for holding together two plates of metal, its headless end being beaten out or pressed down when in place

robot n — a machine capable of carrying out a complex series of actions automatically, especially one programmable by a computer; a machine resembling a human being and able to replicate certain human movements and functions automatically; a person who behaves in a mechanical or unemotional manner

rotate v — move or cause to move in a circle round an axis or centre

rubber n — a tough elastic polymeric substance made from the latex of a tropical plant or synthetically rupture v — break or burst suddenly

rusty adj — covered with, affected by, or consisting of rust which is a brown substance that forms on iron or steel when it comes into contact with water

S

saw n — a hand tool for cutting wood or other hard materials, typically with a long, thin serrated blade and operated using a backwards and forwards movement

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