Notes, summaries, assignments, exams, and exercises for Technology for Baccalaureate

Material Science Timeline

• 1769: Discovery of the steam engine (Watt)
• 1831: Discovery of the dynamo (Faraday)
• 1913: Popularization of stainless steel
• 1950: Discovery of silicones and first use in aircraft
• 1960: Perfection of silicon crystals (almost perfect purity)
• 1962: Discovery of the nickel and titanium alloy
• 1971: Presentation of soft contact lenses (Bausch & Lomb)
• 1983: First mobile phone
• 1991: First Web page

Second Industrial Revolution Key Points

• New production systems improve accelerated production.
• Amendment to the way we produce at all levels.
• Minimization of production costs.

Plastics: An Overview

Plastics are characterized by their plasticity, a property that allows them to be easily molded into the most convenient shapes. Their history began...

Gustave Eiffel — The Eiffel Tower

Work: Eiffel Tower
Author: Gustave Eiffel
Location: Paris
Date: 1887–1889

I. Meaning and Function

In 1887, Gustave Eiffel was commissioned to build an iron tower for the Exposition Universelle to be held in Paris. The tower, at 300 m, whose function is to show its own structural elements, became a symbol of modernity.

Constructive Elements

Constructive elements are prevalent in the Eiffel Tower: the assembly of iron pieces, the methods by which the metal expands and contracts, and the stress calculations. Because it is an open structure, it conveys a sense of lightness that does not correspond to its actual weight.

The four feet at the base, connected by arched structures, recall the origins of the iron bridge...

General Documentation

• Name: Tassel House
• Author: Victor Horta
• Date: 1892 - 1893
• Style: Art Nouveau
• Location: Brussels
• Material: Stone, iron, glass, ceramic, and wood
• Construction System: Industrial materials

Formal Analysis

We are in a formal analysis of the Tassel House floor plan, which is narrow, elongated, and almost rectangular, consisting of three floors. The distribution of the floors is determined by the staircase that starts in the lobby and the rooms that are placed on either side of a corridor. The support elements are fine iron columns that allow for the bypass of load-bearing walls. These columns are decorated in the capital with great imagination and creativity. As for the supported elements, apart from the roof, of note are the iron beams...

Plastics and Polymers

Polymers are synthetic materials created through chemical reactions by human intervention. Additives are included if you want to improve their properties. The main characteristics of plastics are corrosion resistance, thermal insulation, and acoustic and electrical insulation.

Raw Materials Used in Manufacture

In the early nineteenth century: Animal raw materials (silk, milk casein) and plant materials (latex and cellulose) were employed.

Up to approx. 1930: Coal tar was used.

Today: Oil and natural gas are used occasionally.

Common Plastic Additives

To obtain specific properties, certain additives should be added depending on what you look for: colorants, antistatic agents, conductive materials, or stabilizers.

Types of Plastic

Applications of the Freewheel Mechanism

The freewheel mechanism is utilized in rear-wheel bicycles and automobile starters. It transmits motion from the starter to the engine; once the engine reaches a higher speed than the starter, it uncouples to prevent damage.

Ratchet Mechanisms: Definition and Types

A ratchet is a mechanism designed to allow rotation in one direction while preventing it in the other. They are classified as:

• Reversible: The direction of blocking can be changed.
• Non-reversible: Blocks in only one direction.
• Configuration: Can be external or internal.

Description of the Welding Arc

An electrode is connected to a transformer cable. When the electrode is brought close to the parts to be joined, an arc jumps, melting both the electrode...

Introduction to Pneumatics

Pneumatics studies the behavior of air compressed by mechanical pressure and its effects. The fundamental formulas include pressure, P = F / S (where P is pressure, F is force, and S is surface area), and flow rate, Q = V / t in m³/s (where Q is flow rate, V is volume, and t is time). A pneumatic circuit is a device consisting of a set of interconnected elements through which compressed air can circulate.

Pneumatic Circuit Components

A standard pneumatic system with a compressor includes the following essential components:

• Compressor: Increases the atmospheric air pressure up to 6 to 7 bars.
• Auxiliary engine: Communicates the rotary motion of the shaft to the compressor.
• Refrigerator: Diminishes the air temperature at

Classification and Types of Plastics

Thermoplastics: These materials can be molded easily when heated.
Thermosets: Once set, these materials do not regain their molded shape even when reheated.
Elastomers: These are materials characterized by an elastic structure.

Common Plastic Families and Applications

• PC (Polycarbonate): Used in cameras, windows, and helmets.
• PVC (Polyvinyl Chloride): Used for pipes, windows, vinyl, cable sheathing, and syringes.
• PP (Polypropylene): Found in bags, bottles, and small appliances.
• PE (Polyethylene): Used for boxes, toys, bottles, pipes, and bags.
• PMMA (Acrylic): Used in car light covers, bathroom accessories, glasses, and glazing for boats and planes.
• PS (Polystyrene): Used for car interiors, tapes, ribbons, and

Main Characteristics of Machines

Power operation. All machines are supplied with an energy source to function, either by connection to the electric current, battery, combustion of fuel, or using air pressure. Machines transform and transmit energy through mechanisms and internal circuits; apparatuses transform the transmitted or received energy to produce effects. Machines are recognized by the effects of their operation: movement, heat, delivery of images, etc.

Parts of a Machine

Structure. The structure is constituted by the fixed parts of machines; it is the framework on which the rest of the pieces are based.

Mechanisms. Mechanisms are the mobile parts of machines such as toothed wheels, levers, pulleys, rollers, and similar elements.

Circuits.

Products and Services Defined

Goods

Goods are all products that have measurable physical characteristics.

Services

Services are intangible and immaterial products.

Economic Sectors of Companies

Primary Sector Companies

These companies are engaged in activities directly related to the land, such as: agriculture, mining, fisheries, and livestock.

Secondary Sector Companies

These are companies that transform, modify, and process raw materials to create the final product.

Tertiary Sector Companies

These companies offer customer services, including:

• Trade
• Transport
• Banking
• Other services

Company Ownership and Legal Forms

Public Company

A public company is managed and directed by government institutions.

Private Company

A private company is managed and directed by a...

Features: Mechanical resistance, a larger amount of carbon, increased hardness and strength. The most resistant are the beam, shaft, and power transmission systems. Softer elements are used for cold applications and should be addressed. In alloy steels, other factors can yield the best resultant mechanical or chemical properties. Stainless steel incorporates chrome, offering high resistance to corrosion.

Non-ferrous Alloys

• Bronze: An alloy of copper with tin. It is resistant to copper and does not corrode, possessing mechanical properties similar to steel.
• Brass: Formed with copper and zinc. This alloy offers higher hardness and ductility than pure copper.
• Duralumin: Aluminum alloys with other metals. The most common are copper, magnesium, manganese,