unit 2 Flashcards
how do pneumatics work
compressed air/gas is used to create movement eg mechanical drills
how do hydraulics work
made of two pistons connected by a liquid-filled pipe. If one piston is pushed, the force is transmitted through the liquid and the other piston moves. Hydraulic brakes on cars work like this.
how does kinetic pumped storage work
hydroelectric power provides a controllable supply
to top up the National Grid power supply at peak times when more electricity is needed. A kinetic-pumped storage system works by having two reservoirs and a hydroelectric dam system.
so a kinetic-pump plant will pump the water from a lower reservoir up to a higher reservoir, where the water remains. When there is a sudden need for more electricity (spike) during the daytime, the dam is opened and the water from the top reservoir passes through pipes, spinning turbines to quickly produce the electricity needed.
how does kinetic pumped storage work
hydroelectric power provides a controllable supply
eg resevoirs
example of modern material
graphene - 200x stronger than steel
developed from lead
light, strong, flexible, conductor
used in vehicles, planes, and racquets
nano materials -tiny particles are woven into fibres to solve problems. Deodorant in sports socks, antibacterials in wound dressings
LCD - The liquid crystals are between a liquid and solid state. When charge is applied to each liquid crystal, the shape changes to either block light or let light through. This ensures text or images display on the LCD.
smart material definition
reacts to an external stimulus by changing their characteristics and or properties
thermochromic pigments - fever strips, novelty goods, room thermometers
photochromic pigment - UV light reacts with photosensitive particles - prescription sunglasses
self healing concrete - cracks enlarge over time nad water rusts steel frameworks - when water seeps in, bacteria feed, producing calcium carbonate
types of reinforced plastic
carbon fibre reinforced plastic - CRP
glass reinforced plastic - GRP
uses of CRP
sports equipment and helmets
uses of GRP
boat hulls, sports equipment
CRP process
- apply release agent to mould
- apply 1st resin coat
- apply woven carbon fibre
- repeat to desired thickness
- seal in a vacuum bag and heat
- release, trim and finish
GRP process
1.apply a release agent to mould
2. apply a gel coat
3. apply glass fibre matting
4. repeat until desired thickness
5. clamp and leave to cure
6. release, trim, finish
what tasks or events happen within a system
input -> process -> output
such as steering, navigation
what is open loop and close loop difference
open loop does NOT make decisions based on feedback
closed loop relies on feedback to make a decision
open loop
input -> process -> output
timer set -> heating -> toast
closed loop
ellitical - start and finish
parallellogram - input/output
diamond - decision
rectangle - process
is this is correct signal? -> output or go back
