Download unit 2 classification

UNIT 2
CLASSIFICATION
Vocabulary
• Materials: countable vs uncountable nouns
(i.e. general vs specific)
• Revision of names of materials
• (WORD FORMATION: NOUNS from VB)
Grammar and functions
• Expressing classification
• AS, HOW and LIKE
• Introduction to connectors
CLASSIFICATION OF MATERIALS
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ACCORDING TO THE STATE OF MATTER
SOLIDS, e.g. COPPER
GASES, e.g. CARBON DIOXIDE
DIVIDE MATERIALS INTO METALS AND NONMETALS
DEPENDING ON WHETHER THEY ARE PURE
METALS
ALLOYS, e.g BRONZE
METALS CAN BE CLASSIFIED INTO
IRON AND ALL OF ITS ALLOYS
LEAD, GOLD OR MERCURY
CLASSIFICATION OF MATERIALS
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CERAMICS, PLASTICS, COMPOSITES, RUBBER
PLASTICS, …, CAN BE DIVIDED INTO
THEIR MOLECULAR STRUCTURE CHANGES
AS MANY TIMES AS NEEDED
ELECTRICAL CONDUCTIVITY
CONDUCTORS, INSULATORS AND SEMICONDUCTORS
THEY PERMIT AN ELECTRIC CURRENT TO FLOW
MOST METALS
LIKE CARBON OR SALT WATER
PLASTICS AND CERAMICS ARE INSULATORS
SILICON
ACT AS CONDUCTORS OR INSULATORS
IN MANY DIFFERENT WAYS
CLASSIFYING
GENERAL CLASS
is/are
may be
can be
could be
Includes
Contains
consists of
is made up of
is formed by
is composed of
comprises
classified
divided
grouped
arranged
categorized
classified
categorized
classed
grouped
into
divisions
groups
types
classes
categories
as
solids, liquids or gases
CLASSIFYING
SPECIFIC ITEM
is
classed
classified
categorized
is put into
falls into
belongs to
is
as
GENERAL CLASS
the class / category of
GENERAL CLASS
an example (type, kind, form ....) of GENERAL CLASS
IN many / different / various WAYS
CLASSIFYING
Basis of the classification
according to
on the basis of
based on
depending on
criteria
characteristics
the following
features
properties
whether (+ CLAUSE)
COMPLETE THE TABLE
Engineering materials
metals
ferrous
COMPLETE THE TABLE
Engineering materials
non-metals
metals
non-ferrous
lead
gold
ferrous
ceramics
plastics
mercury
thermosets
iron
iron alloys
thermoplastics
HOW / AS / LIKE
HOW
• CÓMO (indirect question) (e.g. He told me how to do it)
• LO + ADJ/ADV (e.g. Tell me how fast the car runs)
LIKE
• Adjective = IGUAL o SEMEJANTE (opposite :“unlike”)
(e.g. Like poles repel and unlike poles attract)
• COMO = PARECIDO A, IGUAL (QUE) (if with vb = -ING)
(e.g. A computer is like a typewriter)
Plastics are composed of long chain-like molecules called polymers
• COMO = POR EJEMPLO (e.g.)
Some metals, like steel or brass, are alloys
Expressions
• TO BE LIKE = SER COMO (e.g. What is it like?)
• TO LOOK LIKE = SER PARECIDO A
(e.g. This object looks like a square box)
AS
AS as a PARTICLE
• Comparative : “as ... as”
(e.g. Thermoplastics can be heated as many times as required)
• In co-relation with THE SAME : “the same as”
(e.g. Rubber has the same properties as plastics)
• EN CALIDAD DE / COMO
(e.g. Oil is used as a fuel)
AS + SENTENCE (Subject + Vb)
• COMO :(e.g. As I was saying, magnetic fields cannot be seen)
• A MEDIDA QUE: (e.g. Steel becomes hard as it cools down)
• PUESTO QUE: Copper is widely used in wires as it is ductile
Expressions
• AS IF / AS THOUGH = COMO SI (+ subjunctive)
• SO AS TO = CON OBJETO DE, PARA (+ infinitive)
• AS FAR AS = EN CUANTO A , CON RESPECTO A
EXERCISE
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AS expected, the lecture began 2 hours late.
I am going to explain HOW electrolysis can be used AS a process to
coat objects with thin films of metals LIKE/SUCH AS chromium or gold.
Electroplating is LIKE painting an object but covering it with a metal.
We can observe HOW the needle moves AS we place the compass
near a coil.
A piece of iron can be used AS a magnet when it is magnetized.
Thermosets break down AS their temperature rises.
Some metals, LIKE/SUCH AS aluminium and copper, are pure metals.
I have never used a device LIKE this one before.
Semiconductors act AS conductors under certain conditions but AS
insulators under others.
Electrons are attracted by positively charged particles AS they have a
negative electric charge.
The boiler of a power plant works LIKE a big kettle.
Some new materials behave LIKE both solids and liquids.
AS tin is fairly weak, it is not used in structures.
Computers may change the order of some instructions SO AS TO
improve performance
CONNECTORS
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Copper is a good conductor, THEREFORE/THUS it is used
in wires.
2. Cast iron is not used to withstand impact loads
BECAUSE/AS/SINCE it is a brittle material.
3. Titanium is used for aircraft frames BECAUSE/AS/SINCE it
is light and strong.
4. Chromium resists corrosion THEREFORE it is added to
steels to make them rust proof.
5. Aluminium and iron are pure metals WHEREAS/WHILE
bronze and steel are alloys
6. Stainless steels have a high strength. HOWEVER, they are
expensive and difficult to machine.
7. Tin is used to coat other materials to protect them
BECAUSE/AS/SINCE it resists corrosion
8. Tin is expensive; THUS/THEREFORE the coats of tin are
very thin.
9. Nickel & chromium improve the properties of metals;
THEREFORE /AS A RESULT they are added to steel
10. Alloys, i.e. / THAT IS mixtures of materials,….
WORD FORMATION
NOUN from VERB
-ing -> English (e.g. building)
-tion/sion ->Latin (e.g. Explanation/emission)
-ment (e.g. management)
- er/or (object) (e.g. boiler/conductor)
- ure (e.g. mixture)
- ent/ant (e.g. content/coolant)
- nce (e.g. performance)
- age (e.g. drainage)
- al (e.g. disposal)
- y (e.g. discovery)
WORD FORMATION
1. EXPOSURE to GASEOUS fluorine.
2. IMPROVEMENTS … RESISTANCE
…FULLY … PITTING
3. DENSITY … its SUBSTITUTION ….
WEIGHT …HARMFUL … EMISSIONS
4. its STRENGTH … its ABILITY …
DEFORMATION …its RESISTANCE … to
DEFLECTION
5. COMPONENTS … CHEMICALLY ….
ENVIRONMENTALLY safer COOLANTS
… higher PRESSURES
WORD FORMATION: Aluminium
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ACTIVITY
ENGINEERING
DEVELOPMENT
APPLICATIONS
TOUGHNESS or DUCTILITY
FAILURE.
ACCEPTANCE
COMPONENTS
REFRIGERANTS or COOLANTS and PRESSURES
WORKABILITY and corrosion RESISTANCE
ABILITY
STRENGTH
TREATMENT
GRAMMAR REVISION
There are MANY (muchos) types of STEEL (acero) DEPENDING
ON/ON THE BASIS OF/ACCORDING TO (según) the
materials added to it.
For example, steel that contains VERY LITTLE (muy poco)
CARBON (carbono) is known AS (como) low carbon steel, and
it is very malleable.
HOWEVER (Sin embargo) steel with a higher carbon content
becomes LESS (menos) malleable, AS (ya que) carbon makes
it harder and THEREFORE (por lo tanto) more difficult TO
MOULD/SHAPE (de moldear), but ON THE OTHER HAND
(por otra parte) it can resist higher loads.
Other types of STEEL (acero) include some other materials,
LIKE/SUCH AS (como) chromium to make STAINLESS
STEEL (acero inoxidable).
THUS (Así pues), we can classify steel INTO (en) different groups
ACCORDING TO (según) the properties that we require and
HOW (cómo) the steel is manufactured.
THE PERIODIC TABLE
• First classification: METALS, SEMIMETALS, NON METALS
• USES
• Non-metals: Most are GASES Examples: OXYGEN and
NITROGEN in THE AIR
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Used in balloons because they are LIGHT GASES
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Low liquefaction point: HELIUM & HYDROGEN uses
PRODUCTION OF LOW TEMPERATURES (e.g.
SUPERCONDUCTING MAGNETS and REFRIGERATION
PURPOSES
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Reactive gases: e.g. CHLORINE and FLUORINE. Reactions
are sometimes a nuisance because they produce CORROSION
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Inert gases: eg ARGON Uses in INDUSTRY because OF THE
OPPOSITE REASON (THEY DO NOT CORRODE)
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For example, it is used to create an inert atmosphere for THE
PRODUCTION OF SPECIAL PLASTICS
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Argon is the cheapest INERT GASES
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Normal atmosphere produces OXIDATION-> critical
degradation of the material -> important if the plastic is to be used
for OPTICAL TRANSMISSION PURPOSES
VIDEO
• Not all non-metals are gases:
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CARBON: Diamond structure -> natural-> uses
JEWELLERY and ornament. Characteristic:
HARDNESS; Use in industry CUTTING VERY HARD
MATERIALS
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GRAPHITE : characteristic VERY SOFT eg. lead
pencils
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another property: CARBON ALSO
CONDUCTS ELECTRICITY eg. dry cell ->
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CARBON is used as one of the ELECTRODES
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Another example: in commercial electrolytic cells
USE OF GRAPHITE