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

Effort

An effort (q) is the internal tension experienced by bodies subjected to an action or several forces.

• Traction: The forces trying to stretch the body over which they apply.
• Compression: The forces trying to crush or compress a body are opposite and act inside the body.
• Flexion: The forces trying to bend the element on which they are applied.
• Torsion: The forces trying to wring the item on which they act.
• Shear: The forces act like two blades of scissors.
• Buckling: It is a composite effort with compression and flexion.

Mechanisms

These are intended to transmit or transform forces and movements from a driving element to another element.

• Mechanisms of transmission of motion: Pass on to another point the motion produced by a driving element.
• Motion

Understanding Plastic Materials: Types and Applications

Thermoplastics: Properties and Common Uses

What are Thermoplastics?

Thermoplastics are composed of polymer chains that are weakly connected to each other. When thermoplastics are heated, they soften and can be molded into different shapes. Once they cool down, this process can be repeated as many times as needed, making them highly recyclable and versatile.

Key Types of Thermoplastics and Their Applications:

• Polyethylene Terephthalate (PET): Impermeable, transparent, and light.
  • Applications: Packaging for food, drinks, personal hygiene products, cosmetics, and cleaning products.
• High-Density Polyethylene (HDPE): Rigid and resistant.
  • Applications: Buckets, bottles, packaging for cleaning products,

parallel circuits

The Importance of Drawing in Civil Engineering

Drawing is a fundamental and very important subject in Civil Engineering. A civil engineer cannot be successful without knowing how to draw. It is the language of engineers. No amount of words can convey civil engineering information as accurately and efficiently as a drawing. An architect cannot describe the plan of a house to a builder unless they draw it. They can only give a general idea using words like "single-storied, three-bedroom house," etc., but without a drawing, there is no way to build the house. This language is the easiest in the world to learn and the most precise. An object can be drawn only in one way. As a corollary, an accurate and complete drawing of an object can represent...

When you need to make a motion transmission, you usually work directly with axes: We support a fixed, usually cylindrical axis, which serves as another element, such as a wheel or a pulley, to turn around. Tree: It's a bar, usually cylindrical, that transmits circular motion. Coupling: The element that allows joining two trees or two axes. Wheel Bearings: These are two completely smooth rim wheels that are in direct contact with one another for moving forward. Gearboxes: We have a minimum of two formed mechanisms, sprockets, constructed in such a way that matches the outgoing motion and transmits circular motion and power. Types of Gears: Cylindrical straight, helical, and bevel. A series of small items would not be possible without the proper...

Mechanical Movement Systems: Transmission and Transformation

This section details the fundamental mechanisms used to transmit or transform movement within mechanical systems.

Mechanisms of Movement Transmission

Transmission mechanisms transfer motion and power from a driving element to a driven element. These include:

• Direct Transmission: Elements are in direct contact (e.g., friction wheels, gears).
• Indirect Transmission: Uses flexible elements (e.g., belt or chain).
• Auxiliary Mechanisms: Clutches, brakes, and turn reversers (inverters).

Direct Transmission Components

Axis (Axle)

A fixed support element around which another component, such as a wheel, rotates.

Shaft

A rotating element that transmits circular motion and power.

Coupling

An element that allows

Programmable Logic Controllers (PLCs) Explained

A Programmable Logic Controller (PLC) is an electronic device capable of processing analog, digital, numeric, and alphanumeric information. It is designed to monitor real-time automated industrial processes. Basically, a PLC consists of a control unit, memory, and input/output modules. PLC manufacturers establish communication with external circuits. These circuits are constituted by sensors that send information from the industrial process to the PLC, and actuators that implement program orders.

Automation Approaches: Wired vs. Programmed

Wired Automation Limitations

Traditional wired automation presents several challenges:

• Requires large conduits and control panels.
• Lacks flexibility; variations do

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

Engineering and Construction Glossary

This glossary provides definitions for key terms used in engineering, construction, and design projects, including their Spanish translations where applicable.

Cross-section (Sección transversal)

A cross-section gives a cutaway view of the joint between two panels.

Note (Notas)

A note gives a brief description or a reference to another related drawing.

Plan (Plano)

A plan gives a view of the whole deck, from above.

Schematic (Esquemático)

A schematic gives a simplified representation of a network of air ducts.

Specification (Especificación)

A specification gives detailed written technical descriptions of a panel.

Amplified

Amplified: made greater.

Elevation (Elevación)

Elevation gives a view of all the panels, from...

STONE MATERIALS: Stone materials are often used for construction because they are strong, durable and very resistant to weather conditions.

1.1. Extracting and processing stone: Stone is extracted from natural deposits. Some types exist as large blocks, such as marble and granite from quarries, which must be cut into smaller pieces. Other materials, such as gravel and sand, are aggregates.

1.2. Natural stone: -Limestone is a porous sedimentary rock. It is often used for sculptures and buildings, as well as for breakwaters in ports. -Limestone is used to produce lime and cement.

-Marble is a hard rock. Marble is cool to the touch and well-known for its resistance to compression and extreme weather conditions. Marble comes in a variety of colors...