History 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
Woodcut and Intaglio Printmaking Techniques
Woodcut
Fiber and very smooth, often used pieces of wood are holly and boxwood, especially from Turkey. This wood is harder than that used in the “straight” technique and thus is carved with a chisel (usually a metal tool). By using chisels, fine lines appear in the resulting picture as a white line drawing. This is opposite to the black line drawing of the woodcut in a row and thus, pictorial engravings can be achieved in the woodcut. Another advantage is that there is no size limit: in the “straight”
Read MoreCombinational & Sequential Systems, Circuits, Resistors, Capacitors
Difference Between Combinational and Sequential Systems
Combinational systems are characterized by their outputs, which depend only on the value of their inputs. In sequential systems, the values of the outputs at any given time depend not only on the inputs but also on the state in which they are.
Multiplexer
A multiplexer is a circuit that allows the selection of which of several input data lines should appear on a single output line. Its main application is to send data through a single output
Read MoreArchitectural Glossary: Terms and Definitions
Architectural Glossary
Common Terms and Definitions
B
Bolt: A bar made of wood or metal that slides into a socket and is used to fasten doors and gates.
C
Clash: A conflict, as between opposing or irreconcilable ideas.
Contractor: A company that agrees to furnish materials or perform services at a specified price, especially for construction work.
Cross-Section: A section formed by a plane cutting through an object, usually at right angles to an axis.
Cutaway: A model or diagram of an object with part of