Understanding Plastics: Types, Manufacturing, and Environmental Impact
Plastic is a synthetic material developed in the 20th century, derived from organic compounds like petroleum and other natural polymers through chemical reactions. These reactions create large molecules containing carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur. Plastics are versatile materials found in nearly all types of everyday objects. Many plastics share characteristics such as being electrical insulators, lightweight, and easy to work with.
Obtaining Plastics
Plastics are obtained
Read MoreUnderstanding Electronics: Semiconductors, Diodes, and Transistors
The Basics of Electronics
The fundamentals of electronic technology are closely related to the behavior of electrons and various phenomena. The field of electronics, divided into multiple disciplines, has experienced rapid development in this century. Electronics has played a crucial role in this advancement, starting with vacuum tubes, then diodes and transistors, and subsequently with integrated circuits and microprocessors.
Semiconductors
Semiconductors are materials with properties between those
Read MoreElectronics Components and Concepts Explained
Electronics Components and Concepts
Diode: Two-terminal device that conducts in only one direction.
Fuse: Protective device that breaks when current exceeds a maximum value.
LED: Electronic device that conducts current in one direction only and lights when it is conducting.
Resistor: Component made of material that opposes the flow of current and has some value of resistance.
Resistor Colour Code: Coding system of coloured stripes on a resistor to indicate its value and tolerance.
PLCC: A square IC package
Read MoreHistory and Impact of Tool Development
The First Tools
A tool is any device capable of multiplying the intensity or energy efficiency of the arm. The development of tools progressed through various stages:
- Stone carving (Australopithecus)
- Stone shaping (Homo habilis)
- Advanced stone tools (Homo erectus)
Homo sapiens revolutionized tool construction, using bone, wood, amber, and other materials to create needles, punches, harpoons, and scrapers.
Metals
Around 12,000 years ago, humans discovered how to cast metals from ore. The first metals
Read MoreElectrical Terms and Definitions: A-Z Glossary
Alternating Current (AC)
Alternating current (AC): Electric current that reverses its flow direction at constant intervals.
Ampere (A)
Ampere (A): The unit used to measure an electric current.
Circuit Breakers / Fuses
Circuit breakers / fuses: These devices are installed in the service panel of your home to limit the flow of current through a circuit. The rating of the breaker will determine its maximum flow.
Circuit Extensions
Circuit extensions: This is when you extend or add on to an existing circuit
Read MorePower Systems: Generation, Transmission, and Distribution
UNIT 1
Power Systems: Generation, Transmission, Distribution
Generation (1-30kV), Transmission (115-800kV), Distribution (2.4-69kV), Consumers (120/240V).
Generated power = Consumed power.
Base demand: Needed all the time (100%).
Intermediate demand: Constant for a long time.
Peak demand: Changing all the time.
Hydro Power (1)
P = 9.8 * q * h
- P (kW)
- q (flow rate)
- h (water head)
V = A * d
Time (t) = V / q
Hydro Power (2)
- Base power: 100MW
- Peak power: 60MW
Thermal Power (1)
η = (1 – T2 / T1)
- η = efficiency
- T1