1. Describing processes:
UNIT 7
Vocabulary
Conventional Power Plants:
Thermal power plant
Nuclear power plant
Grammar and functions
ORAL PRACTICE
Describing processes:
Important expressions
ALLOW/CAUSE/PREVENT (U5 p60)
Active vs. Passive
Revision of vb tenses (regular & irregular vbs)
Revision of grammar structures

2. DESCRIBING PROCESSES IMPORTANT EXPRESSIONS (U10 p122) COMMON VERBS
Use of the PASSIVE
To carry out / develop a process
The process takes place / occurs / happens
This ALLOWS / CAUSES it TO occur (U5)
This PREVENTS it FROM occurring (U5)
The process RESULTS IN the generation of electricity (U5)
The process CONVERTS/TRANSFORMS/CHANGES INTO !! BECOMES N/Ad SEQUENCE of STEPS: First, Then, Finally. Before/After this. During, As
METHOD (U6) (HOW?)
PASSIVE + BY = por
by means of ... / (by) using ... / With the help of ... Through … mediante, por medio de, con ….
One method for /way of ... (+ verb –ING) .... is to ....
PURPOSE (U6) (WHAT FOR?)
In order to, so as to, to + INF = Para + Inf
So that + sentence (S+Vb) = para QUE

3. CAUSE/PERMIT/PREVENT (U5 p60)
CAUSE: TO CAUSE + OBJ + TO INFINITIVE
TO MAKE + OBJ + BASE FORM OF THE VERB
hacer que + frase
PERMIT: TO PERMIT + OBJECT + TO INFINITIVE
TO ALLOW + OBJECT + TO INFINITIVE
TO ENABLE + OBJECT + TO INFINITIVE
TO LET + OBJECT + BASE FORM OF THE VERB
permitir que + frase
PREVENT: TO PREVENT + OBJECT + FROM + -ING
TO AVOID + OBJECT + FROM + -ING
TO STOP + OBJECT + FROM + -ING
TO KEEP + OBJECT + FROM + -ING
impedir que + frase

4. EXERCISE CAUSE/ALLOW/PREVENT (U5p60)
The recommendation of various alternatives can permit the company to determine which one is best for the particular situation.
Chemical degradation is a process in which additives cause plastic to crumble away.
The composite fibers prevent some kinds of brittle materials from cracking.
Known as rapid solidification, the process causes the atoms to freeze in place before they can align in a crystalline lattice.
Lighter and more heat tolerant than metals, ceramics permit the engine to run hotter, and therefore more efficiently.
When ceramic is unable to bend, a strong impact will cause it to crack.
Stress ceramics prevent the crystalline planes from deforming.
Superconductors permit electrons to flow indefinitely.
Carbon dioxide permits the infrared rays to pass through the atmosphere but prevents them from leaving again.
Insulators prevent electrons from flowing through them.

5. TRANSLATION p 81
GREAT/LARGE AMOUNTS OF ELECTRICITY CANNOT BE GENERATED UNLESS ) a coil rotates in a magnetic field
that IS DONE BY MEANS OF/WITH A TURBINE (that is) connected to a generator
The turbine converts the kinetic or thermal energy of a flowing fluid INTO useful rotational energy
A generator contains the stator, WHICH IS THE MAGNET and a rotor, WHICH IS THE COIL
WHEN/AS THE ROTOR TURNS the wires cut the lines of force in the magnetic field of the stator
PRODUCING AN ALTERNATING CURRENT
The enormous size of modern generators and the speed AT WHICH the rotor can turn mean that electric power of very high voltage can be produced
AS MUCH AS HALF A MILLION VOLTS can be transmitted over high voltage lines to substations
IN WHICH THE VOLTAGE IS REDUCED WITH / BY ( BY MEANS OF) / BY USING TRANSFORMERS

6. TRANSLATION p 82 The rotor is turned BY/ BY MEANS OF / WITH a turbine,
a huge machine (that is ) moved by water or STEAM IN POWER PLANTS
ACCORDING TO/DEPENDING ON THE SOURCE OF ENERGY (that is) USED to move the turbine
By far, the most important sources of power are those (sources) (which are) produced by THE CHEMICAL ENERGY OF/FROM FOSSIL FUELS, LIKE/SUCH AS OIL OR COAL , nuclear energy and the potential energy of waterfalls.
Fossil-fueled power plants contain a boiler WHICH WORKS LIKE a big kettle.
AFTER BEING HEATED (UP) TO A CERTAIN TEMPERATURE, the steam is passed through small holes, increasing the speed of the water molecules
The fast moving molecules hit the blades of the turbine and MAKE IT (THEM) TURN / CAUSE THEM TO TURN.

7. VIDEO p 82: Coal PP (Utube 0-1:50)
Where is half of world’s electricity generated? By coal power plants
How many are there in the world? Close to 3,000 large coal PP
How this controversial yet indispensable PP works, i.e. how to convert the energy stored in the COAL to ELECTRICITY
To increase burning efficiency a POWDERED COAL and air MIXTURE enters the furnace
During the burning process the chemical energy stored in the coal is released as heat to create high temperatures inside the furnace.
This heat passes to the water inside the coils located in the furnace.
The hot water is then forced to move to the boiler where it evaporates and generates high-pressure steam.
The high-pressure steam is taken to the steam turbine
The energy inside the steam is converted into mechanical energy.
This mechanical energy is then transferred to the generator where it will be converted into electricity
The generated electricity is finally transferred to the grid through a transformer and is ready to be consumed by the public

8. ACTIVE vs PASSIVE p 84 Passive voice:
Typical in TECNICAL ENGLISH, particularly when describing processes.
The pyramids were built thousands of years ago.
The samples were analysed in the laboratory
The mixture is fed into the pulveriser.
NOTE:
- Some verbs have NO PASSIVE (intransitive, impersonal) =
e.g. RAIN, AGREE, APPEAR, ARRIVE, OCCUR, HAPPEN, BECOME, RISE, BELONG, CONSIST (of), DEPEND, EXIST, DIE, FALL, LIVE, WAIT, HAVE, modals (CAN, MAY, MUST)
Be careful with Spanish expression “se + vb”:
e.g. se lava las manos = he washes his hands;
Polos opuestos se atraen = unlike poles attract each other
The reaction spreads out very quickly
AGENT => BY (por) = The system was developed BY the engineers of the plant
if an object = BY / BY MEANS OF / USING / WITH / THROUGH
e.g. : The system was developed BY / BY MEANS OF / USING a new technique

9. PASSIVE VOICE p 84 Past Part of MAIN VERB. TO BE (changing verb) +
+ DEVELOPED
The system …..
PRESENT = IS
PRESENT CONT= IS BEING
PAST = WAS (WERE)
PRESENT PERFECT = HAS (HAVE) BEEN
PAST PERFECT = HAD BEEN
WITH MODAL VB = CAN/MUST BE
WILL / SHOULD = BE
GERUND = BEING
PAST PARTICIPLE = BEEN

10. NUCLEAR ENERGY 84-85
Nuclear energy is the energy (that is) RELEASED through the fission or fusion of atomic nuclei.
In the process (that is) KNOWN AS nuclear fusion two light atoms join together UNDER conditions of extreme HEAT and PRESSURE (at LEAST 50,000,000 degrees Celsius) until they merge, forming a new nucleus WHOSE mass is only slightly smaller THAN the total masses of the nuclei that FUSE together.
The opposite process is nuclear FISSION which MEANS “splitting apart” or “dividing”.
If either nuclear fusion or fission TAKES place quickly, the result is a sudden release of ENERGY but so far the only one THAT can BE SLOWED down and CONTROLLED is fission.

11. NUCLEAR ENERGY 84-85
However, only A FEW elements are suitable FOR use.
When one of THESE elements is STRUCK/STRIKEN by a free neutron, IT SPLITS / BREAKS/ IS BROKEN down INTO two lighter nuclei, WHICH fly apart AT high speeds, colliding WITH surrounding atoms.
This kinetic energy IS CONVERTED INTO heat.
AT the same time, two or three more neutrons ARE RELEASED and one of THEM enters the nucleus of a neighbouring atom, causing fission TO OCCUR again,….
The reaction SPREADS very quickly with more and more energy (that is) RELEASED.
This IS REFERRED to as A “chain” reaction because the splitting of each nucleus IS LINKED to another.

12. NUCLEAR ENERGY 84-85
If this reaction IS UNCONTROLLED, the result is an atomic explosion like THAT (the explosion) (which was) CAUSED by the atomic bombs of Hiroshima and Nagasaki.
However, the reaction can BE SLOWED down and that is WHAT happens in a nuclear reactor or pile.
Here the highly fissile material IS SURROUNDED BY a substance that is non-fissile, FOR instance, graphite.
This material IS CALLED A moderator.
The neutrons LOSE some of THEIR energy through COLLIDING with the atoms of the moderator and no expansion IS PRODUCED .
by SLOWING down the speed of the free neutrons, IT makes it …. collide WITH the nucleus of a neighbouring atom to continue the chain REACTION

13. NUCLEAR ENERGY 84-85
The major advantage of nuclear energy is that it DOES NOT DEPEND ON any local factors.
A nuclear reactor, UNLIKE conventional power plants, DOES not have TO BE BUILT near a fossil-fuel source, nor does it depend ON a large flow of water WHICH may BE REDUCED during some seasons of the year.

14. VERBS (regular&irregular)
TO KNOW
KNEW KNOWN
TO SHOW
SHOWED SHOWN
TO LEAVE
LEFT LEFT
TO STRIKE
STRUCK STRUCK/STRIKEN
TO LET
LET LET
TO SEE
SAW SEEN
TO CUT
CUT CUT
TO LEAD
LED LED
TO TAKE
TOOK TAKEN
TO SPLIT
SPLIT SPLIT
TO WIND
WOUND WOUND
TO FEED
FED FED
TO SET
SET SET
TO DRIVE
DROVE DRIVEN
TO ALLOW
ALLOWED
TO FLOW
FLOWED

15. VERBS (regular&irregular)
TO DRAW
DREW DRAWN
TO SPREAD
SPREAD SPREAD
TO RAISE
RAISED
TO BUILD
BUILT BUILT
TO SPEND
SPENT SPENT
TO FIND
FOUND FOUND
TO MAKE
MADE MADE
TO SUPPLY
SUPPLIED
TO THROW
THREW THROWN
TO BURN
BURNT BURNT
TO RISE
ROSE RISEN
TO HOLD
HELD HELD
TO BREAK
BROKE BROKEN
TO PUT
PUT PUT
TO BRING
BROUGHT BROUGHT
TO GIVE
GAVE GIVEN

16. VIDEO p 86: Nuclear reactor
URANIUM
the exact SIZE that is USED in the fuel rods.
This TINY pellet CONTAINS more ENERGY than 6 car loads of coal.
We have 20 MILLION of these pellets INSIDE the reactor vessel.
We call it the CORE.
Around the core, of course, there is WATER.
WATER is used as a COOLANT.
Now, … another set of rods called the CONTROL RODS.
These rods actually control the NUCLEAR REACTION.
What happens is this: …. that is when it is ACTIVATED,
with them gone, the NUCLEAR FUEL sets up a CHAIN REACTION
that PRODUCES a tremendous AMOUNT of HEAT,
that BOILS the WATER,
that turns to STEAM,
that TURNS the TURBINE,
that turns the GENERATOR, that PRODUCES ELECTRICITY.

17. GRAMMAR REVISION p86: THE NUCLEAR REACTOR
… place IN which a fission NUCLEAR reaction TAKES place.
It contains …in THE form of rods to produce the appropriate result.
The reactor consists OF a fuel, a moderator and A cooling system.
An instrument …neutron WHICH strikes the nucleus of an atom of U-235.
The nucleus … which collide WITH other nuclei and split, and so on.
However, if no explosion occurs IT is because …is moderated BY a non-fissionable material such AS graphite or heavy water.
This absorbs most OF the free neutrons and prevents them FROM splitting too MANY nuclei too quickly.
The process releases great AMOUNTS of energy in the form of heat.
This heat ….produced can be USED to generate electric power.
As the fuel … during ITS use inside the reactor, when IT is taken …, IT is stored in the fuel pools, …, in general more THAN a year, before sending IT to the processing plant.

18. LISTENING p87: comparison of fuels
about different fuels and processes. We’ve been told that nuclear power is more efficient than conventional fossil fuels and we know that fossil fuels are limited.
-Conventional fossil fuels, i.e., oil, coal and gas, and nuclear fuels, i.e., uranium and plutonium.
-different nuclear reactors and different conventional processes.
-Say a bucket holds 10 kg
Let’s look at the 2 million Kw power station.
2 million kw make 2,000 megawatts
That’s nuclear fuel
which converts all the matter in this fuel into energy.
it may last 8 ½ years. In fact, ….. with the hydrogen fusion reactor.
Only two weeks
- The next process is a fast reactor. …. natural uranium.
After three days. Now let’s look at conventional fossil fuels, shall we? …. One hour?
-it will last 1/18th of a second. And the same goes with coal.
-In Europe, France, and then West Germany.