Notes, summaries, assignments, exams, and exercises for Technology for Secondary education

Nick Srnicek on Data and 21st-Century Systems

In this chapter, Nick Srnicek examines the raw material central to the system focus in the 21st century: data. Srnicek demystifies the critique of data collection as a mere monitoring method.

On the one hand, he warns that caution should be exercised regarding the belief that data collection and analysis is an automated and uncomplicated process. On the other hand, he lists the processes that make them profitable. The real problem for capitalist companies was that old business models were not well designed to extract and use data. A different business model was needed, and platforms emerged.

Platforms became an efficient way to monopolize, extract, analyze, and use the increasing amounts of data being...

Feasible (Factible)

Possible to do. Example: With the extra resources, the scheme now seems feasible.

Forklift (Máquina elevadora)

A small vehicle with two strong metal bars on the front, used for lifting heavy goods.

Full-scale Drawing (Dibujo a gran escala)

A drawing where the dimensions are the same as the real size of the object.

General Arrangement Drawing (Plano de disposición general)

Shows the layout of an entire assembly or structure, but does not provide details of smaller individual components.

Grid D14 (Cuadrícula D14)

In the designs of large structures, a grid is often superimposed on plan drawings to allow elements and installations to be located relative to the gridlines.

High Bay Warehouse (Almacén alto)

A tall warehouse, approximately

I. Types of Fibres

There are two types of fibres:

• Natural fibres: Obtained from natural sources (e.g., cotton, silk, wool).
• Synthetic fibres: Man-made fibres (e.g., rayon, nylon, acrylic).

II. Understanding Polymers

A synthetic fibre is a chain of small units of chemical substances joined together. Many such single units combine to form a single unit called a polymer. The term polymer means "made of many units joined together."

III. Types of Synthetic Fibres

• Rayon: Synthesized from wood pulp. It resembles silk, so it is also known as artificial silk. Rayon can be dyed in different colours and is much cheaper than silk.
• Nylon: The first commercially synthesized fibre. It is made from coal, water, and air. Nylon is very strong and its fabric resembles

Gears: Basic Concepts

1. What are gears and what are they used for?

They are mechanical elements designed to transmit turning movements.

2. What does it mean when two gears "engage"?

It means their teeth fit into those of another similar wheel.

3. What are the two main characteristics of gears? How are they represented?

The two main characteristics are the number of teeth (Z) and the rotational speed (N).

4. What happens if two gears have a different number of teeth? And if they have the same number?

• If they have a different number of teeth, the smaller gear rotates faster than the larger gear.
• If they have the same number of teeth, they rotate at the same speed.

5. In a pair of gears, what role does the motor gear have? And the output gear?

• The motor

Internet and Connectivity

• Wireless network: A network where users can access the internet without using any cables.
• To go online: To use the internet.
• Wi-Fi hotspots: A public place where you can access the internet.
• To surf the web: To look through websites, searching for something you need, or simply for entertainment.
• Download (podcasts): To save a copy of a file from the internet to your own device.
• To browse websites: To search for websites.
• To access websites/email: To visit websites or email.
• To navigate a website: To find what you need on a website.
• Social media: Media used to interact with other people.
• Send an attachment: Send an email with an added file.

Hardware and Software Basics

• Large screen: A big-sized monitor.
• Gadget: An advanced piece

Fossil Fuel Power Stations

Fossil fuels, such as coal, oil, and natural gas, are used to heat water in a boiler. Steam from the boiler turns a turbine, which is connected to the rotor of a generator. The generator produces electricity, which is transported by a network of high voltage power lines. After that, the steam goes to a condenser where it cools and becomes liquid water again. Finally, the water is pumped back to the boiler.

Combined Cycle Power Stations

Electricity is generated in two systems. In the first, natural gas is burned with compressed air. This produces superheated gases which turn a turbine to generate electricity. In the second, the hot gases from the first system are used to produce steam in a heat recovery boiler. Then the...

Mechanism Classification

Mechanisms can be classified based on their function:

• Transmission of Motion:
  • Linear transmission (lever, pulley)
  • Rotatory transmission (gears and belt drive)
• Transformation of Motion:
  • Rotatory-linear (wheel, crank)
  • Reciprocating rotatory-linear (cam, crank and rod)
• Motion Control:
  • Direction control (ratchet and freewheel)
  • Speed reduction (brake)
• Energy Accumulation:
  • Absorption/dissipation (spring)
• Connection:
  • Linkage (clutch)
  • Support (plain bearing)

Energy and Work in Mechanisms

Mechanisms seem to increase force, but they cannot create energy on their own. All mechanisms produce the same amount of work that is done to them, including energy that is lost to friction and heat. If a mechanism increases force, it must decrease motion....

Understanding Materials: Plastics and Building Essentials

Plastics: Properties, Types, and Applications

Plastics are versatile, man-made materials, predominantly derived from oil. The fundamental process of creating a polymer is known as polymerization. Plastics are broadly categorized into two main types:

• Thermoplastics
• Thermosetting Plastics

Thermoplastics Explained

Thermoplastics can be repeatedly heated, molded, and reshaped. A unique characteristic of thermoplastics is their plastic memory, meaning each time they are heated, they tend to return to their original shape.

Thermosetting Plastics Explained

Thermosetting plastics are generally strong and highly resistant to heat. They undergo a permanent chemical change upon initial heating to a sufficiently...

Engine Ignition Timing Setup

Commissioning an engine's power system involves precisely timing the spark plug ignition within each cylinder. This ensures the spark plugs ignite the fuel-air mixture at the precise moment for optimal combustion.

1. Breaker Contact Adjustment

Since the adjustment of the breaker contacts directly influences the ignition point, this operation must be performed first. Use feeler gauges inserted between the contacts to set their maximum separation. This separation should be approximately 0.30 to 0.40 mm.

2. Positioning Piston 1 for Ignition

Once the breaker contact separation is adjusted, proceed to position cylinder #1's piston at the end of its compression stroke and the beginning of its power stroke (ignition point)....