PRACTICAL SESSION CONTROLS It is compulsory to ATTEND & COMPLETE at least 4 Practical sessions, i.e. Doing the ORAL practice Answering VIDEO QUESTIONS (on paper) Taking the CONTROL TEST at the end of the sessions (PoliformaT -> examenes) PRACTICAL SESSIONS will ONLY be COMPLETE if you have OK in the VIDEO & CONTROL TEST & you have done the ORAL practice You can download the programme in a pendrive to complete your sessions You can DELIVER/COLLECT your papers from my office door pocket

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 p23 There are many different classifications for materials; thus ACCORDING TO THE STATE OF MATTER we find SOLIDS, like COPPER, liquids such as water and GASES, for example CARBON DIOXIDE A more interesting classification for engineers, however, is to divide materials INTO METALS AND NON-METALS We can classify metals DEPENDING ON whether THEY ARE PURE METALS, like aluminium, or ALLOYS for example BRONZE In addition, METALS CAN BE CLASSIFIED INTO ferrous and non ferrous metals. In the first category we may include IRON AND ALL OF ITS ALLOYS whereas LEAD, GOLD OR MERCURY fall into the group of non-ferrous metals.

CLASSIFICATION OF MATERIALS p23 With respect to non-metals, we can mention CERAMICS, PLASTICS, COMPOSITES, RUBBER and so on. PLASTICS on the other hand, CAN BE DIVIDED INTO thermoplastics and thermosets. The latter cannot be reheated as THEIR MOLECULAR STRUCTURE CHANGES whereas the former do not undergo changes when heated; therefore they can be reshaped AS MANY TIMES AS NEEDED On the basis of their ELECTRICAL CONDUCTIVITY a further classification of materials could be made into CONDUCTORS, INSULATORS AND SEMICONDUCTORS depending on how readily THEY PERMIT AN ELECTRIC CURRENT TO FLOW

CLASSIFICATION OF MATERIALS p23 MOST METALS are good conductors; however, there are also some non-metals which conduct well, LIKE CARBON OR SALT WATER On the other hand, PLASTICS AND CERAMICS ARE INSULATORS as they do not permit the flow of electricity. Examples of semiconductors are SILICON or germanium; these materials ACT AS CONDUCTORS OR INSULATORS depending on the impurities added to them. As we have seen, materials can be classified IN MANY DIFFERENT WAYS depending on the feature that we use as the basis of the classification.

CLASSIFYING p 25 GENERAL CLASS classifieddivisions dividedgroups groupedintotypes is/arearrangedclasses may becategorizedcategories can be could beclassified categorized classedassolids, liquids or gases grouped Includes Contains consists of is made up of is formed by is composed of comprises

CLASSIFYING p 25 SPECIFIC ITEM classed isclassifiedasGENERAL CLASS categorized is put into falls intothe class / category ofGENERAL CLASS belongs to isan example (type, kind, form....) of GENERAL CLASS INmany / different / various WAYS

CLASSIFYING p 25 Basis of the classification criteria according tocharacteristics on the basis of the following based on features depending onproperties whether (+ CLAUSE)

COMPLETE THE TABLE p 24 Engineering materials metals ferrous

COMPLETE THE TABLE p24 Engineering materials non-ferrous lead thermoplastics plastics non-metals metals ferrous ceramics goldmercury ironiron alloys thermosets

HOW / AS / LIKE p26 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/ How nice!) LIKE Adjective = IGUAL o SEMEJANTE (opposite :“unlike”) (e.g. Like poles repel and unlike poles attract) COMO = PARECIDO A, IGUAL (QUE) (+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?= DESCRIBING) TO LOOK LIKE = SER PARECIDO A (e.g. This object looks like a square box)

AS p26 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 As (it is) shown in the graph) 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/LONG AS = SIEMPRE Y CUANDO AS WELL AS = ASI COMO, Y TAMBIEN (addition)

EXERCISE p27 1.AS expected, the lecture began 2 hours late. 2.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. 3.Electroplating is LIKE painting an object but covering it with a metal. 4.We can observe HOW the needle moves AS we place the compass near a coil. 5.A piece of iron can be used AS a magnet when it is magnetized. 6.Thermosets break down AS their temperature rises. 7.Some metals, LIKE/SUCH AS aluminium and copper, are pure metals. 8.I have never used a device LIKE this one before. 9.Semiconductors act AS conductors under certain conditions but AS insulators under others. 10.Electrons are attracted by positively charged particles AS they have a negative electric charge. 11.The boiler of a power plant works LIKE a big kettle. 12.Some new materials behave LIKE both solids and liquids. 13.AS tin is fairly weak, it is not used in structures. 14.Computers may change the order of some instructions SO AS TO improve performance

CONNECTORS 1.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 ACTIVITY ENGINEERING DEVELOPMENT APPLICATIONS TOUGHNESS or DUCTILITY FAILURE. ACCEPTANCE COMPONENTS REFRIGERANTS or COOLANTS and PRESSURES WORKABILITY and corrosion RESISTANCE ABILITY STRENGTH TREATMENT

GRAMMAR REVISION p29 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 Used in balloons because they are LIGHT GASES Low liquefaction point: HELIUM & HYDROGEN uses PRODUCTION OF LOW TEMPERATURES (e.g. SUPERCONDUCTING MAGNETS and REFRIGERATION PURPOSES Reactive gases: e.g. CHLORINE and FLUORINE. Reactions are sometimes a nuisance because they produce CORROSION Inert gases: eg ARGON Uses in INDUSTRY because OF THE OPPOSITE REASON (THEY DO NOT CORRODE) For example, it is used to create an inert atmosphere for THE PRODUCTION OF SPECIAL PLASTICS Argon is the cheapest INERT GASES 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: CARBON: Diamond structure -> natural-> uses JEWELLERY and ornament. Characteristic: HARDNESS; Use in industry CUTTING VERY HARD MATERIALS GRAPHITE : characteristic VERY SOFT eg. lead pencils another property: CARBON ALSO CONDUCTS ELECTRICITY eg. dry cell -> CARBON is used as one of the ELECTRODES Another example: in commercial electrolytic cells USE OF GRAPHITE