PLASTICS AND TEXTILES VOCABULARY

-Packaging:Embalaje
-Plastics:Plásticos
-Molecules:Moléculas
-Natural plastics:Plásticos naturales
-Obtained:Adquirido
-Sources:Fuentes
-Synthetic plastics:Plásticos sintéticos
-Compounds:Compuestos
-Polymerisation:Polimerización
-Fillers:Rellenos
-Enhance:Mejorar
-Additives:Adicionales
-Rigid:Rígido
-Resistant:Resistente
-Insulators:Aislantes
-Ductile:Dúctil
-Malleable:Maleable
-Light:Ligero
-Impermeable:Impermeable
-Recyclable:Reciclable
-Chemical recycling:Reciclaje químico
-Mechanical recycling:Reciclaje mecánico
-Energy recovery:Recuperación de energía
-Non-biodegradable plastic:Plástico no biodegradable
-Biodegradable plastic:Plástico biodegradable
-Thermoplastics:Termoplásticos
-Soften:Ablandar
-Thermosetting plastics:Plásticos termoestables
-Elastomers:Elastómeros

-Polyethylene terephthalate:Tereftalato de polietileno
-High-density polyethylene:Polietileno de alta densidad

-Polyvinyl chloride:Cloruro de polivinilo
-Low-density polyethylene:Polietileno de baja densidad
-Polypropylene:Polipropileno
-Polystyrene:Poliestireno       
-Moulded:Moldeado
-Expanded:Expandido   
-Methacrylate:Metacrilato       
-Teflon:Teflón
-Cellophane:Celofán    
-Nylon:Nylon      

-Polyurethane:Poliuretano
-Bakelite:Baquelita
-Melamine:Melamina
-Polyester resins:Resinas de poliéster        
-Natural rubber:Caucho natural

-Synthetic rubber:Caucho sintético
-Neoprene:Neopreno
-Extrusion:Extrusión
-Calendering:Calandrado
-Vacuum forming:Formación de vacío
-Moulding:Moldura
-Thermoplastic:Termoplástico

-Moulds:Moldes
-Thermosetting:Termoestable
-Measuring:Medición
-Marking:Calificación
-Cutting:Corte
-Drilling:Perforación
-Filing and sanding:File y lijado
-Joining:Unión
-Carpenter's square:Escuadra del carpintero
-Ruler:Regla
-Measuring tape:Cinta métrica
-Protractor:Transportador
-Scissors:Tijeras
-Utility knife:Cuchillo de uso
-Hacksaw:Sierra
-Jigsaw:Rompecabezas
-Punch:Perforadora
-Hot wire cutter:Cortador de cables
-Drill:Taladro
-Bit:Barra de metal
-Tap and handle:Manija
-File:Lija
-Sandpaper:Papel de lija
-Belt sander:Lijadora de banda
-Orbital sander:Lijadora orbital
-Bolts, nuts and washers:Tornillos, tuercas y arandelas
-Threaded:Enhebrado

-Adhesives:Adhesivos
-Two-part resins:Resinas de dos partes
-Acrylic cement:Cemento acrílico
-Contact adhesives:Adhesivos de contacto
-Soldering:Soldadura
-Heat sealer:Sellador de calor
-Hot air welder:Soldador de aire caliente
-Natural:Natural
-Synthetic:Sintético
-Wool:Lana
-Silk:Seda
-Cotton:Algodón
-Esparto:Esparto
-Linen:Lino
-Bamboo:Bambú
-Metallic fibres:Fibras metálicas

BASIC DEVICES MADE WITH ELECTRONIC COMPONENTS

1.Timers
It is a device that operates for a certain period of time and then shuts itself off automatically:


-At first, the LED is off,since there is no current flowing through the base. When we push the button, current flows through the base , and the transistor is activated, and the LED turns on. The capacitor also begins to charge itself.


-When we release the button, the LED continues to produce ligh for some time, using current from the capacitor.

2.Integrated circuits
They consist of miniature electronic components.

                             

ELECTRONICS III

Transistors
They are basic components of electrical circuits. They are made from semiconductor materials and have three electrodes: the base, the collector and the emitter.
There are two types of transistor: NPN and PNP.

• When no electrons are flowing through the base, it is in cut off.
• When many electrons are flowing through the base, it is in saturation.
• When the flow of electrons through the base is between the cut off and saturation levels, it is in the active region.

ELECTRONICS II

-Capacitors
They can store electrical energy from a battery and then use it to power a light bulb until the charge is totally depleted. This is measured in farads.

-Diodes

They are electronic components made from semiconductor materials. A diode has two electrodes: an anode and a cathode.

A LED only gives off light when an electric current flows through it.

ELECTRONICS I

-Fixed resistance or resistor
It opposes the flow of electric currents. Its value is indicated by this code of colours and numbers:

-Variable resistance or potentiometer

Its value can be adjusted between zero and the maximum value specified by the manufacturer.

-Resistance that depends on a physical factor

• Resistance that depends on temperatura is called termistor. There are two types: negative and positive.
• LDR: resistance that varies according to the amount of light received.

ELECTROMAGNETIC CONTROL SYSTEMS

An electromagnetic control system activates the various parts of a machine, at the right moment and for the right amount of time, ensuring that the machine functions properly.


-Cam switch controller: the shape of a cam allows us to control the moment and duration of an activity.

-Limit switches: the switch is activated when the float rises to a certain level. When the wáter level goes down, the switch returns to its original position and the pump turns on again.

There are two types of limit switch: normally closed and normally open.

ELECTROMAGNETIC MECHANISMS

1.Electromagnetic generators
They transform mechanical energy into electricity. Generators that produce direct current are called dynamos, and those that produce alternating current are called alternators.


-Dynamo: consists of a magnet and a rotary coil, that have, at the end, two semi-circular conductors, wich form the commutator.

-Alternator: is almost identical to a dynamo, except for the commutator, wich consists of two metallic rings connected to carbón brushes.

2.Electric motors
Is a device that can transform electrical energy into movement.

3.Relays

Is an electromagnetic component that works as a switch. When electricity passes through the coil, it acts like a magnet.

EFFECTS OF ELECTRIC CURRENT

1.Heat
The energy that an electric current produces as heat is called Joule Effect. It is exprssed by the following formula:              E = I(square) x R x t


2.Light
There are various ways that electricity can be used to produced light:

• Incandescent bulbs.When an electric current passes throughthe metallic filament of a light bulb, it produces light.

• Fluorescent tubes. When an electric current passes through the filament, electrons are emitted into the inert gas.

• Light-emitting diodes (LED). When electricity is applied to the LED, the electrons and holes cross over into the active layer, where they combine and produce photons, or particles of light.

3.Electromagnetic effect

Michael Faraday discovered that electricity could be generated by using a magnet and an electrical conductor. This principle allows us to build dynamos and alternators.

4.Sound
We can transform electric current into sound by using electromechanical devices, such as bells and buzzers. Some of these devices are based on the piezoelectric effect.

TYPES OF CURRENT

1.Direct current
We have direct current when the electrons always flow in the same direction with the same current.


2.Alternating current
In this case, the flow of electrons changes direction 50 times every second. In addition, the electric current is not always the same.

The variation of any electrical parameter over a period of time is an electric signal.


The average power of alternating current is equal to the direct current that is needed to produce the same effect. In this case of an alternating sinusoidal current, the average power would be as follow:

V(ef)=V(max)/square root of 2

Alternating current can be increased or decreased by a transformer(V1/V2=n1/n2).

TYPES OF CIRCUITS

1.Series circuit

Two or more elements form a series circuit when the output of one element provides the input for the next element.

To calculate the total resistance of a series circuit, we add the resistance values of each load:

R=R1+R2+R3...

2.Parallel circuit 

In a parallel circuit, the various components share the same input and output.

The equivalent resistance of this type of circuit would be:

1/R=1/R1+1/R2+1/R3...

3.Combination circuit

A combination circuit has some elements connected in series and other elements connected in parallel.



ELECTRICAL QUANTITIES

1.Voltage or potential difference
The amount of energy that a generator can transfer to electrons depends on its voltage. This is measured in volts (V).
We use a voltmeter to measure voltage. This object must be connected in parallel to the element that we are checking.


2.Intensity or electric current
It is the charge or number of electrons that flow through the cross-section of a conductor every second. It is measured in amperes or amps (A).
We use an ammeter to measure electric current. It must be connected in series.


3.Electrical resistance
The resistance (R) of a material is equal to the voltage divided by the intensity of the electric current wich travels through the material. This is measured in ohms.


4.Electrical energy
It is is the tension that flows, in a certain time, in an electric current. We can calculate it with this formula: E=VxIxt. It is measured in joules (J).


5.Electric power
It is the amount of energy that it can transform over a certain amount of time. It is measured in watts (W) or kilowatts (kW).             P=VxI       E=Pxt




*In the points 1,2 and 3 we can use the Ohm`s Law to calculate it:    R=V/T

AN ELECTRIC CIRCUIT

An electric circuit is a pathway for the flow of electrons, that is called electric current.


-Parts of an electric circuit:

• Generators provide the energy that electrons need in order to move. Examples: cells and batteries.

 

• Loads are devices that transform electrical energy into other types of energy that we can use. Examples: light bulbs, motors, resistors and bells.



• Switching devices are used to direct and interrupt the flow of electric current. Examples: switches, push buttons and 3-way switches.

-Symbols in a diagram:

ELECTRIC POWER STATIONS THAT USE NON-RENEWABLE ENERGY SOURCES

1.Thermal power stations that use fossil fuels
Fossil fuels are used to heat water in a boiler. Steam from the boiler turns a turbine , wich is connected to the rotor of a generator. This produces electricity. After that, the steam goes to a condenser , where it cools and becomes liquid water again, wich is pumped back to the boiler.

2.Nuclear power stations

They work like a termal power station, but this use radioactive materials such as uranium.

-Advantages: productivity and profitability.

-Disadvantages: risks of nuclear accidents and management and storage of radioactive waste.



ELECTRICAL ENERGY

Electrical energy is a form of energy that is transported by an eléctrica current.


Electricity is very common for two reasons:
-It can be easily transformedinto other types of energy.
-It can be transported over long distances.


1.Electric power stations
A power station is a place where energy from natural resources is transformed into energy.
If the energy obtained is electricity, it is called an electric power station.


They use generators (alternators) to transform energy into electricity.

2.The transportation and distribution of electricity

• Raisin the voltage: it is raised to avoid the loss of energy as heat.
• High voltage lines:  are carefully planned and the lines are intalled on towers.
• Reducing the voltage: electrical substations are installed between high voltage lines and final consumers.
• Power is distributed: to homes, offices... The electric lines are usually suported by posts, and the voltage is reduced to very low ranges.

ENERGY SOURCES

Energy sources are natural resources that we can use to generate different forms of energy. Then we can transform that energy for various purposes.


We can classify energy sources into two general categories:

1.Non-renewable energy sources

Come from natural resources that are limited and can be exhausted. They include:

-Fossil fuels (oil, coal ...)

-Nuclear energy (radioactive materials)

2.Renewable energy sources

Come from natural resources that we cannot use up completly. These include: hydroelectric, solar, marine, geotermal and biomass resources.

ENERGY TRANSFORMATIONS

Energy can be transformed, but it cannot be created or destroyed. This is the principle of energy conservation. These are some examples:

ENERGY

Energy is the capacity of a body to perform transformations and do work.

1.Forms of energy:

2.Units of measurement for energy:

In the International System, energy is measured in joules. When energy takes the form of heat, we often express in calories.


3.Power
The power of a machine is the amount of work that it can do in a certain amount of time. We express this relationship as:       P=W/t
The relationship between input and output energy in any machine is expressed as its energy conversion efficiency:           Energy conversion efficiency(%)=(output/input)·100