Notes, summaries, assignments, exams, and problems for Technology

1. Plastic Materials: Polymers and monomers.

2. Thermoplastics: Softened by heating and can be melted multiple times.

• Polyethylene (PE): Bags, bottles, containers.
• Polystyrene: Packaging, heat insulation.
• Polyvinyl Chloride: High-resistant pipes, cables.
• Polypropylene: Model and dye resistant, toys.
• Polyethylene Terephthalate (PET): Recyclable, transparent dye, bottles.
• Teflon: Resistant to chemicals and high temperatures, used in frying pans.
• Polycarbonate: Resistant to impact and heat.

Thermosets: Form permanent networks.

• Melamine: Withstands high temperatures and chemicals, used in wooden boards.
• Bakelite: Hard and brittle dark plastic, used for handles of kitchen utensils.
• Polyester Resins: Rigid and brittle, strengthened with fiberglass for swimming

My Favorite Website

The website that I usually visit is NewPCT1. The page is full of text links. The appearance of this page is good, tidy, nice, and easy to use. The site map is well-organized because it divides the content into sections, and it is only necessary to choose the one that you wish to view. The search option arranges content by series, movies, programs, games, and music. Inside each of these sections, you have many subcategories to choose from. It is very comfortable to navigate this website. It has many links, but all are positioned in such a way that it is easy to use.

Unit 11: Networking Fundamentals

• File Server: A file server provides a central storage area for data files.
• Bridge: A bridge is a hardware and software combination

List of Essential ICT Services

1. List the services that must be provided in the new ICT and indicates which are mandatory and which are optional. Solution:

• Service radio and television (RTV): capture, adapt and distribute radio and television signals that reach the building, so they can be interpreted by the user receivers.
• Telephone service available to the public (STDP): providing access to telephone and data transmission through the basic telephone network (TB) or integrated services digital network (ISDN).
• Service broadband telecommunications: to provide access to telecommunications services broadband (television, data, etc.), cable (TBA) or a wireless (SAI), promoting the development of the Digital Home.

2. Description of the Common Area of

Q1. Synchronous

1. Asynchronous
2. Isochronous
3. None of the above

Q2. Full Duplex

1. Half Duplex
2. Simplex
3. All of the above

Q3. Modulation

1. De-modulation
2. Multiplexing
3. De-multiplexing

Q4. TDM

1. WDM
2. CDM
3. All of the above

Q5. FDM

1. TDM
2. WDM
3. CDM

Q6. Electrical

1. Light
2. Electromagnetic
3. All of the above

Q7. Less Susceptible

1. More Susceptible
2. Not Susceptible
3. None of the above

Q8. Fiber Optic

1. Twisted Pair Cable
2. Coaxial Cable
3. Both B & C

Q9. Reflected

1. Refracted
2. Travelling along the boundary
3. None of the above

Q10. Digital

1. Analogue
2. Both A & B
3. None of the above

Q11. Phase and in Amplitude

1. Phase and Frequency
2. Amplitude and Frequency
3. All of the above

Q12. Increased Unused Slots

1. Decrease the Unused Slots (Maybe)
2. Eliminating Unused Slots
3. Do Not Deal with Unused Slots

Q13. Mathematical Formula

1. Analogue Signal
2. Digital Signal
3. Any

Transformers

Alternating current can be increased or decreased by a transformer. This allows us to transfer electrical energy at very high voltages and over hundreds of kilometers, without losing any of the energy as heat. Transformers consist of two windings made of copper wire. If we apply an alternating current to one of them, it will produce a certain voltage in the other.

Electromagnetic Effects

He noticed that electricity could be generated by using a magnet and an electrical conductor. This principle allows us to build dynamos and alternators.

Effects of Electric Current: Heat

The movement of electrons through an electrical cable is both slow and disorderly. The electrons often collide, increasing the temperature of the cable itself.

Light

For... Continue reading "Understanding Transformers, Electromagnetic Effects, and Electrical Current" »

Industrial Transformations

Understanding Computer Networks

A computer network is a set of computers connected to each other, enabling them to share resources and exchange information. They can share printers, files, folders, and Internet connections.

Ethernet Classification

The two common types of Ethernet networks are 100Base-T and 1000Base-T.

The number indicates the transmission speed in Megabits per second: 100Mbps and 1000Mbps, respectively.

The letter 'T' indicates the type of cable used to transmit data. The cable consists of twisted pairs of copper wire with RJ45 connectors at each end. These cables are used to connect the network.

Types of Cables

• Twisted Pair UTP: 8 copper wires twisted together in 4 pairs with an RJ45 connector at the end.
• STP: A safer cable for transmitting

Wood

Pith: the middle part of the trunk

Heartwood: hardest and darkest, best part for woodwork

Sapwood: recent growth used for more artistic woodwork

Bark: exterior layer, protects the plant from outside attacks

Cambium: thin transparent layer of live cells

Hardwood

Beech: used in furniture and floors because it bends and is easily shaped

Oak: used in parquet floors, boats, etc.

Mahogany: used in joinery, musical instruments, etc.

Softwood

Pine: used in electrical posts, boats, etc.

Silver fir: used in building, carpentry, etc.

White poplar: used in frames, paper, etc.

Engineered Wood

Plywood: formed by gluing together thin sheets with synthetic resins

Chipboard: made with wood shavings and chips which are glued together

Fibreboard: fibers come from grinding

Carpentry

Scanning Tunneling Microscopy (STM) and Atomic Force Microscopy (AFM)

Scanning Tunneling Microscopy (STM)

Scanning Tunneling Microscopy (STM) is an instrument used for imaging surfaces at the atomic level, revealing the topography of conductive specimens. It measures tunneling current and can be used in air, water, and various gas environments, at temperatures ranging from near zero Kelvin to a few hundred degrees Celsius. STM operates in two modes: constant interaction mode and constant height mode.

Advantages of STM

• High resolution, not limited by diffraction
• Small sample size
• Can modify samples to create small structures
• Does not require a partial vacuum

Disadvantages of STM

• Difficult to determine detailed shapes
• Slow scanning speed
• Small image sizes
• Not