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

Nickel Steels

Nickel steels are known for their stainless and electrical properties. Nickel increases the tensile strength, yield stress, elongation, and impact strength or resilience of steel, while simultaneously reducing the influence of heat expansion. Steels containing 10 to 15% nickel can be hardened even with slow cooling.

Chromium Steels

Chromium imparts hardness and deeper penetration of the temper, allowing for oil hardening. Steels with 1.15 to 1.30% carbon and 0.80 to 1% chromium are used for film production due to their hardness. Smaller-scale applications use steels with 0.3-0.4% carbon and 1% chromium.

Chrome-Nickel Steels

More commonly used than chromium steels alone, chrome-nickel steels are employed in various ratios. Examples... Continue reading "Alloy Steels: Properties and Applications" »

Simple Machines: Core Concepts and Skills

Conceptual Content

• Simple Machines: Basic mechanical devices.
• Units of Measurement: Conventional and unconventional measures.
• The Lever:
  • Elements: Support Point/Fulcrum (A), Power Point/Effort (P), and Resistance Point (R).
  • Lever Classes: First-Class, Second-Class, and Third-Class levers.
  • Law of the Lever: Principles governing ideal and real levers.
• The Inclined Plane:
  • Law of the Inclined Plane: Principles governing ideal and real inclined planes.
  • Concept of Angle: Understanding the angle of inclination.
• Measuring Instruments: Dynamometer, Ruler/Scale.

Procedural Skills

Research Abilities

• Observation and description of the parts of a lever.
• Classification of different types of levers according to their class.
• Identification,

Classification of Heating Hot Water Distribution System Function Adopted

Bitubular Distribution

It is characterized by the existence of two tubes, one for supply and a return, mounted in parallel. This ensures a uniform water temperature. The power of the radiators can be achieved by uprights or anillos.

Monotubular Distribution

The entire set of pipes and radiators is bound by a single distribution pipe for hot water to form a closed circuit. The water passes through all the radiators, decreasing in temperature as it moves towards the final radiator anillo.

Radiant Heating Systems

Radiant heating systems operate at temperatures between 25 to 35 ºC, radiating heat from the bottom up evenly.

Function of the Expansion Tank

What is the function of the

Water Seals

Purpose: To prevent foul odors from sanitation pipes while allowing easy passage of water carrying suspended solids.

Types:

• Boat siphon
• P-trap
• S-trap
• Bottle siphon

Drainage Pipe Flow

In a drainage pipe with free-flow regime, what is the relationship between the slope and unit head loss? The relationship is complex; however, a greater slope generally leads to faster flow, which can increase the risk of siphonage.

What is Siphonage?

Siphonage is a phenomenon that occurs during the discharge of a fixture, often called autosiphonage, due to the rapid flow. This typically happens when the discharge pipe is very long, has a small diameter, or is not vented.

Define and Describe a Siphon Pot

A device installed between plumbing fixtures and the main... Continue reading "Plumbing Drainage and Heating System Fundamentals" »

1. Purpose and Scope

The purpose of this instruction is to identify the requirements for electrical installations in furniture and related items. The requirements of this instruction apply to:

• Furniture of all kinds, including office furniture, desks, exhibitors, panels, and similar fixed or mobile items.
• Furniture, mirrors, and bathroom items in rooms containing a bath or shower.

The receivers used in these facilities must meet the requirements of applicable European Directives, as provided for in Article 6 of the Regulation for Low Voltage Electro. To this effect, any furniture marketed with mounted electrical equipment (e.g., lights, switches, socket bases, etc.) shall be considered a receiver.

2. Furniture Not Installed in Bathrooms

Included... Continue reading "Electrical Installation Requirements for Furniture" »

Timber Protection Systems

Felling Season

The sap inside the tree at the time of logging can serve as food for fungi and insects. Therefore, logging should occur when sap flow is lowest, typically during the winter.

Sap Removal

It is necessary to remove the sap from the wood vessels. This is done by washing the timber to dissolve starchy substances.

Sap removal can be achieved through:

• Water Washing (Leaching): This process takes 1 to 3 months.
• Steaming (Vaporization): This method is much faster. The high temperatures used also kill insects and fungi that may have developed in the tree.

Drying

Drying aims to eliminate moisture from the timber. Key objectives include:

• Stabilizing the wood dimensions.
• Preventing the growth and progression of fungi.

• Increasing

Hydraulic Power Unit Components & Functions

A hydraulic power unit is the assembly that provides power to the fluid to operate a hydraulic circuit. It typically consists of the following essential elements:

• Pump: Generates fluid flow.
• Tank: Stores hydraulic fluid.
• Relief Valve: Protects the system from overpressure.
• Actuator: Converts hydraulic energy into mechanical motion.
• Selector Valve: Directs fluid flow to different parts of the circuit.
• Anti-return Valve: Prevents backflow of fluid.

Mobile vs. Fixed Hydraulic Power Units

The distinction between mobile and fixed hydraulic power units lies primarily in their application and portability:

• Mobile Hydraulic Power Units: These systems are designed for applications where the power unit is not stationary.

Mechanical Motion Transformers

A. Rack and Pinion

This system uses a normal gear meshing with a gear of infinite radius (rack). The rack's teeth are trapezoidal, and the system's operation is reversible. Depending on which element is driving and which is fixed, we have:

• Pinion rotates, rack fixed: The pinion moves linearly. This is used in winches for manual carriage movement.
• Rack moves, pinion fixed: The pinion rotates. This has few current applications, formerly used in mechanical calculators.
• Pinion rotates in place: The rack moves linearly. This is used in drill presses, automobile steering, and automatic garage doors.

B. Screw-Nut

The most common application involves rotating the screw while preventing the nut from rotating, causing the nut... Continue reading "Mechanical Motion Transformers and Coupling Elements" »

What is an Aquifer and How Does it Relate to Hydrostatic Pressure?

An aquifer is a geological formation capable of storing and transmitting water through its pores and cracks, making it hydraulically usable. Aquifers are classified based on their hydrostatic pressure:

• Free Aquifer: The free surface of the water is below the ceiling of the aquifer, so it is at atmospheric pressure.
• Confined Aquifer: The water is above atmospheric pressure, filling all the pores. When the roof of the aquifer is pierced, the water rises to reach a hydrostatic equilibrium.
• Leaky Aquifer: A type of confined aquifer where the wall and/or ceiling are semipermeable, acting as an aquitard.

An aquitard is a geological formation that contains water but transmits it very slowly.... Continue reading "Aquifers, Hydrostatic Pressure, and Hydraulic Systems" »

Classification of Technical Drawings

Technical drawings, as defined by standards like UNE 1 to 166 - 1:1996, ISO 10209 - 1:92, or DIN 199, are classified into different types based on their representation, form, content, and purpose.

Technical Drawings by Representation

• Sketch: Freehand representations used for initial product development.
• Scale Drawing: Accurate representations drawn to scale, including all necessary technical details.

Technical Drawings by Form

• Original Drawing: The initial drawing, created manually or using CAD software, typically on transparent paper.
• Reproduction: A copy of the original drawing, produced through printing, photography, or blueprinting.

Technical Drawings by Content

• Assembly Drawing: A comprehensive drawing showing