Section 2 Flashcards
(51 cards)
Shale gas
natural gas trapped with in the earths crust rich in petroleum and natural gas
has to be extracted by controversial process fracking(drill hole, shoot chemical mixture to release gas)
it is harmful for the environment as it releases chemicsl and toxic particles into water table
nuclear power good and bad
produces very little co2 emissions
it is considered non finite by some as there is a very high uranium supply
it creates nuclear waste which has to be disposed of and can cause accidents
wind turbine good and bad
relatively cheap and clean
do not work with too much/low wind
they can harm wildlife and birds
people are against them as they destroy natural views
solar energy good and bad
N : only produce energy in they day time
produce less in the winter months
need to be cleaned and require space
tidal energy
movement of water generates electricity by spinning a turbine
G : it is more predictable and consistent than solar or wind
it has to be placed offshore in hard locations, making installation and maintenance expensive
HEP
hydroelectric power - large areas of land are flooded into reservoirs
N: high set up costs financially and environmentally. need to flood and destroy wildlife
G: reservoirs can become leisure sites and promote new wildlife and become nature reserves
water flow through turbine is easily controlled to meet power demand
biofuel
oil and starch producing crops are used to make fuels like biodiesel
G : stops food waste from being wasted and is carbon neutral
N: crops require high amounts of water, land and contribute to food shortages when used for fuel not feeding
pneumatics and hydraulics
transfer mechanical energy through compression of fluids
compression is delivered through a pimp called a compressor which creates pressure
pressure is measured in bar
flywheel
provides continuous energy when energy source is continuous
it evens out erratic energy supplies by storing it when demand is low
it acts as a generator and also motor(aka makes and stores energy as momentum then back to electrical)
it is put in a vacuum and on good bearing to make for frictionless environment
Batteries, how they have improved, types of batteries
1 or more cells together make a battery each cell is 1.5volts
batteries have become smaller in a process called miniaturisation and also more powerful
acid base- traditional type
alkaline cells - use dense paste materials so can be smaller
rechargeable- used for many modern technologies and reduce production costs
disposal of batteries
batteries must be disposed of correctly or otherwise if they enter a landfill they can contaminate soil and wildlife
they are shredded and recovered to be remade
corn starch polymers examples and G B
plastics made from cornstarch rather than petrochemicals
PLA - polyactic acid
PHB - polyhydroxybutate
G: biodégradable, so no effect on the environemtn and not derived from fossil fuel hydrocarbons so no co2 emissions
B: easily décompose so cannot be mixed with other thermoplastics in recycling or entire batch is invalid
Flexible MDF
(Medium Density
Fibreboard)
Made from wood pulp fibre with grooves cut which make it flexible for modern furniture which is curved
Titanium properties and uses
high strength to weight ratio, used in medical professions alot as it is unreactive and in spacecraft alloyed to have higher strength
Fibre Optics
wires that use lights emission to transfer data, infinite, faster but more expensive
Graphene
A single graphite layers which exhibits extremely higher strength compared to its thinness. To be used in electronic and biomedicine
LCD (liquid crystal display)
monochrome and full colour screens which use crystals with a voltage applied to them. Have to be backlit.
nanoparticles uses
nano-medicine computer circuits antibacterials cosmetics
Metal Foam
Lightweight and porous, but still retain properties of metals
Polymorph
biodegradable polymer which can be moulded at
62C and is useful for prototypes as it can be reheated and moulded
smart materials two example
materials that react to external stimuli which changes it properties
fhermocrhomic and photo chromic
can eventually lose ability to return to pre stimulus state
more examples of smart material
Nitinol- nickel titanium alloy used to make stent. Heat to 540 degree to program memory and then heat again to 70 to turn to programmed state
self healing materials - materials with micro encapsulated resin and bio concrete respond to fractures by seeping in and fixing them used for buildings
QTC(quantum tunnelling composite) - polymer that responds to pressure by becoming more conductive used for wearable technology
piezoelectric materials - a voltage is induced across material when stress is applied or vice versa. used for gas lighters
litmus paper - changes colour when in different pH levels, used for scientific testing
composite materials
two or more materials are joined together to create a material with desired characteristics from both
example of fibre resins
GRP - glass fibre matting covered with gel coat for high strength to weight
carbon fibre - cloth woven with this carbon crystalline filaments
high strength to weight ratio of fibre combines with hardwearing property of resin
