Chapter 2-Energy, Materials, Sytems And Devices(Part 1) Flashcards
How does turbines and generators work?
- Fossil fuels burned to create heat
- The heat super heats Water
- Resulting steam used to rotate turbines
- Rotating turbine turns a generator on
- Generator converts mechanical energy from turbine into electrical energy
Examples of finite resources
- Coal
- Gas
- Oil
What is Shale?
- A sedimentary rock
- Contains a rich source of petroleum and natural gas
Explain how fracking works
- Process of extracting gas from shale
- Drilling a well down into the Earth’s crust
- Sending high pressure water+ chemical mixture into the rock to release trapped gas
- Gad travels up the drilled shaft and collected at the well head
What Kinds of Damage dies fracking do on the environment?
- Releases gases and toxic particles into water tables
- Could cause earth tremors
What are renewable energy sources?
Energy that comes form the planet’s non-finite resources
Advantages of using wind turbines
- Cheap
- Produce power in winter months when demand is higher
- Renewable
Disadvantages of using Wind turbines
- Expensive to make
- Loud
- Migrating birds could die
Explain passive solar technology
Positing a building to gain heat from the sun
Explain active solar technology
- Using photovoltaic cells
- Converting solar energy into electrical energy
- Light photos hit the PV cell, allows electrons to flow creating an electrical current
Advantages of solar energy
- Low maintenance
- Clean energy
- Relatively low cost
Disadvantages of solar energy
- Quite brittle
- Seasonal fluctuations
- No power generated at night
Explain how tidal energy works
Relies on the movement of water to turn turbines which drive the generators that produce electricity
One benefit and one disadvantage of tidal energy
- More predictable and generally more consistent
- Environment were machinery needs to be located- conditions are harsh-makes maintenance difficult
Explain hydroelectric power (HEP)
- Process of using a dam to channel water through turbines that are used to turn generators
- Most Efficient during periods of heavy rainfall
How is biofuel and biomass created?
- Made from organic matter which is burned to generate power
- Can also make biodiesel
Advantages of biomass
- Seen as carbon neutral as they absorb CO2
- Can replace crops very quickly
Disadvantages of biomass
- Can contribute to food shortages in developing countries
Examples of biomass fuels
- Food from farm waste
- Compost
- Wood chips
Explain how nuclear power works
- Nuclear reaction happens inside the reactor vessel
- Makes a lot of heat which superheated water
- Generates power by driving turbines and generators
What is fission?
The process in which uranium atoms are split and produce heat
Disadvantages of nuclear power
- Very expensive to build reactor
- Waste product from reaction is radioactive
- Waste usually stored underground
Mechanical power is stored by…..
- Compression
- Tension
- Motion
Chemical energy is stored by…….
- Batteries
- Gases
- Solid fuel(coal, oil etc.)
- Food
What is pneumatics?
Another form of compression to store gas or air under pressure
Benefits of using pneumatics
- Accurate
- Efficient
- Relatively low maintenance
What is hydraulics?
The gas in pneumatic system can be swapped for a liquid, most commonly oil ( this type of movement is known as hydraulics)
Where are hydraulics commonly used?
- Car breaking systems
- Lifting gear ( Truck+Fork lifts)
What do both pneumatic and hydraulics need?
- Both need compression in order for systems to operate
- Usually delivered by a pump called a compressor
How does a pump build up pressure in pneumatic and hydraulic systems?
When the pressure in the tank falls below minimum, the compressor will automatically turn on and build the pressure back up to the maximum level
What kind of objects have kinetic energy?
An object in motion
What kind of energy has potential energy?
Objects not in motion
How is potential energy converted to kinetic energy?
When some force acts on the object to set it in motion
Ways to store potential energy
- Springs
- Balloons
- Elastic bands
What is the purpose of a flywheel?
- It’s a way to store kinetic energy
- Can provide continuous energy
What can be stored in batteries?
- Electrical power
- Batteries contain electrochemicals that react with each other to produce electricity
How many volts does 1 battery cell carry?
- Approx 1.5v
What is miniaturisation?
When you manufacture smaller mechanical or electrical products to help save finite materials
Describe an Alkaline battery
- Have higher capacity for their size
- Contains dense manganese oxide
- Uses less space but provides the same power
- Hold their charge very well
Advantages of rechargeable batteries
- Can be charged many hundreds of times
- Reduces quantity of resources needed
- Reduces amount of batteries disposed
Why do batteries need to be disposed correctly?
- They contain toxic electrochemicals
- Contain some metals that are harmful to the environment
- If disposed incorrectly chemicals could potentially end up in rivers and soil and cause harm to wildlife
What are corn starch polymers made from?+ Features about them
- Vegetable starches
- They are fully biodegradable
- Cannot be recycled as they decompose easily
Polylactic acid
PLA
- It’s a corn starch polymer
Appearance- smooth/textured finish
Characteristics- Widely used in 3D printers/Easily moulded
Uses- Bottles, Pens, Disposable food and drink containers
Polyhdroxy butyrate
pHB
Bio pool
- It’s a corn starch polymer
Appearance- Smooth or textured finish/easily coloured
Characteristics- Stable,stiff,Quite brittle
Uses- Bottles, Pots, Disposable food containers
Flexible MDF
Medium Density Fibreboard
Appearance-Light brown/cut on one side and smooth on the other
Characteristics- Flexible in one direction along the cut groove, easily shaped into natural curves
Uses- Modern furniture, Interior walls
Titanium
- This metal is usually alloyed with other metals to enhance its properties
- Pure titanium does not react with the human body
Appearance- Light grey/ can be polished to a mirror finish
Characteristics- High strength to weight ratio, anti- corrosive
Uses- Jewellery, Medical uses such as joints, Spacecrafts
Fibre optics
- Allows digital information to travel as a pulse of light along thin glass strands at very high speeds
Appearance- Clear glass fibre core covered with strengthening fibres
Characteristics- Flexile cable that transfers digital data at extremely fast speeds
Uses- Endoscopic cameras ( used to investigate human body), Data transfer cables
Graphene
Appearance- Ultra thin layer of graphite, one Aton thick
Characteristics- conductive, transparent, lightweight, incredibly strong
Uses- Medical industry, Electronic industry, Energy industry
Liquid Crystal display
LCD
- It’s a laminated material of 2 layers of glass with a liquid Crystal core
-2 versions monochrome and full colour - Monochrome- Appear dark when when voltage is applied
- Full colour- offer full screen images
Characteristics- Low power consumption, sharp images
Uses- Watches, clocks, TV screens
What are nano-materials?
- A nanometer is 1 billionth of a metre
Uses- Surface coating, computer chips, clothing(to absorb sweat)
How can a metal be made into foam?
By injecting gas into the metal when it’s in a liquid state
Metal foams
Appearance- Closed or open cell structure, same colour as base metal
Characteristics- Strong, lightweight, very porous, conductive, good sound absorption
Uses- Impact absorption in vehicle, soundproofing
What is Polymorph?
It’s a non-toxic and fully biodegradable polymer that comes in small plastic granules
Ploycaprolactone
PCL
Appearance- translucent pellet that can be hand shaped
Characteristics- Easily mouldable and re-mouldable, fully biodegradable
Uses- Hand shaped artefacts, Prototyping, Jewellery
Stimulus- Heat
Teflon
- A polymer
- Also called PTFE
- Unreactive
Uses- Non stick pan, Clothing and pipes
What is a smart material?
A material that changes its properties in response to a change in it’s environment
Thermochromic pigments
Stimulus: Heat
Appearance- it’s a powder that’s added to materials
Characteristics- colour of pigment changes depending on temp
Uses- children’s cutlery, flexible thermometers, clothing
Photochromic pigments
Stimulus: UV light
Appearance- pigment added to variety of materials
Characteristics- longer it is exposed to UV, the darker it becomes until it reaches maximum
Uses- Sunglasses, beach products, paints
What is nitinol made up of?
- It is an alloy of nickel and titanium
- It is the most commonly used SMA
- Can also be used as a muscle wire-used in dental braces
Shape memory alloys
SMA
Stimulus: Heat or electricity
Appearance- Mid grey metal varying thickness also available in sheets
Characteristics- can be deformed and will return to memory shape when reheated to 70 degrees
Uses- Dental braces, Frames for glasses
Give 2 examples of materials that can respond to stress fractures and repair themselves
Self healing polymers
Bio-concrete
How does a self healing polymer work?
- They contain microencapsulated resin based adhesives
- Used when stress fractures are caused
- Resin fills cracks and hardens
Quantum Tunnelling Composite
QTC
Stimulus: Pressure
- Has the ability to be a conductor or an insulator
- More pressure the conductive the material becomes
Uses- Wearable technology, Speed controllers
Piezoelectric material
Stimulus: Movement, stress or electricity
- Produces and electrical voltage when squeezed or put under pressure
- Quartz is a natural piezoelectric material
Uses- Mobile phone speakers, Gas lighter ignition spark
Litmus paper
Stimulus:PH - Changes colour depending on PH level of a substance - Turns red in acid - Turns blue in alkaline Uses- Soil testing, Swimming pools
