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

Essential Passive and Active Electronic Components

Resistors: Current Control and Sensing

Fixed resistors act as current limiters and are used to protect other components that cannot handle very high current. Resistor applications include:

• Fixed Resistors: Used for current limiting and voltage division.
• Potentiometers (Variable Resistors): Can vary resistance, making them useful as voltage regulators and power controls.
• Dependent Resistors (Sensors): Allow use as sensors in automatic systems (e.g., LDRs, Thermistors).

Capacitors: Charge Storage and Filtering

Capacitors are passive components designed to store electric charge. The main characteristic of a capacitor is its capacitance (C), representing the amount of electric charge (Q) it is capable... Continue reading "Essential Electronic Components and Circuit Prototyping Techniques" »

Hard Drives: Types and Fundamentals

The two most common types of hard drives are IDE (Integrated Drive Electronics) and SATA (Serial Advanced Technology Attachment).

Physical Structure of Hard Drives

Hard drives serve as the primary mass storage unit of a computer. They typically contain multiple platters stacked on a central spindle, completely isolated from the outside environment. At the bottom of the hard disk is a circuit board (or controller card) that receives commands from the system controller. This board also ensures that the spindle maintains a constant rotational speed and manages when the unit reads from or writes to the disk. Modern disks commonly reach speeds of 7200 RPM (revolutions per minute).

A group of read/write heads, mounted... Continue reading "Computer Hard Drives: Types, Structure, and Setup" »

Service-Oriented Architecture (SOA) Explained

Service-Oriented Architecture (SOA) is not a specific software or framework. Instead, it is a methodology and a pattern for designing systems where components and service providers interact.

Advantages of SOA

• Software Reuse

  Complex routines needed by multiple systems within a company can be developed as web services, promoting reuse.

• Increased Productivity

  Connecting to an existing web service is often faster than building the entire required functionality for a new system.

• Greater Agility

  With the assurance of no duplicate code across the system, system maintenance becomes significantly faster.

• Interoperability

  This enables seamless information exchange between systems written in different programming languages.

Mechanical Properties of Materials

• Elasticity: The ability of a material to recover its original shape after deformation.
• Plasticity: The ability of a material to retain its deformed shape after the applied load is removed.
• Ductility: The ability of a material to be stretched into thin wires or threads without fracturing.
• Malleability: The ability of a material to be hammered or pressed into thin sheets without fracturing.
• Hardness: The resistance of a material to scratching, indentation, or abrasion.
• Fragility: The tendency of a material to break with little or no plastic deformation; lack of toughness.
• Toughness: The ability of a material to absorb energy and deform plastically before fracturing.
• Fatigue: The progressive and localized structural

Aluminum

Alumina Reduction Process

The reduction of alumina is a process conducted in steel cells, where carbon blocks act as anodes.

Aluminum Alloys

Aluminum is alloyed with elements such as copper, zinc, magnesium, manganese, and silicon to enhance its properties.

Aluminum Applications

Aluminum is widely used due to its unique properties:

• Reduced Density

  Ideal for aerospace, automotive, and railway industries due to its lightweight nature.

• Good Electrical Conductivity

  Utilized as conduits in high-voltage overhead power lines.

• Corrosion Resistance

  Used for manufacturing tanks for substances like acetic acid and beer.

• High Reflectivity

  In powder form, it's used for making reflective paints due to its high reflectivity.

• Oxygen Affinity

  Acts as a reducing agent

Classification of Consumption Sites

Consumption sites are primarily classified as:

• Residential or Commercial: Buildings intended for living or business purposes.
• Office: Buildings specifically designed for office use.
• Industry-Specific: Facilities tailored to the needs of a particular industry.
• Industrial Concentration: Areas designated for a cluster of industries.

Load Forecasting

Load forecasting considerations for different building types:

• Housing: Residential buildings.
• General Services: Common areas and shared facilities.
• Shops and Offices: Commercial spaces and office buildings.
• Garages: Parking facilities.

Degree of Electrification

• Basic Electrification: Designed to meet primary usage needs, allowing for common household equipment (5750 W).
• High Electrification:

Development and Implementation of Demolition

1. Dismantling of industrial equipment.
2. Demolition or removal of bodies and covered ledges.
3. Demolition or removal of the deck.
4. Demolition of elements at each plant: interior partition walls, curtain walls, and cargo.
5. Demolition of structural elements: forged with beams, reinforced concrete slabs (one-direction, two-directions), beams, brackets, domes.

Types of Demolition

According to Procedure

1. Element by element.
2. With collapse.
3. Mixed or combined.

According to Media

1. Manual.
2. Mechanical.
3. Thermal.
4. By explosives.

Design of a Sanitation Network

• If the network is public: Mixed.
• If two networks (wastewater and stormwater): Separator system.

Basic Sanitation Network Requirements

1. Dispose of water seal to prevent the passage of air.

Types of Ferrous Metals

Ferrous metals are primarily industrial iron, steel, and cast iron.

Industrial Iron

Industrial iron has a low carbon content and inadequate mechanical characteristics, making it rarely used in industries.

Steel

Steels are ductile and malleable. Mechanical strength, hardness, and brittleness increase with carbon content, while weldability decreases with the percentage of carbon. Steel is also prone to rust. There are two main types of steels: carbon steels (those with low content of other elements) and alloy steels (containing other elements).

Various elements communicate a range of properties to steel. These include sulfur, cobalt, chromium, manganese, molybdenum, nickel, lead, silicon, vanadium, and tungsten.

Cast Iron

Casting... Continue reading "Ferrous Metals: Types, Properties, and Steelmaking Processes" »

Machines and Energy

Machines use energy to perform useful work.

Fossil Fuels

Fossil fuels, such as coal, oil, and natural gas, can be burned to release heat energy.

Nuclear Fuel

Nuclear fuel, including uranium and radioactive materials like plutonium, can undergo fission reactions to produce electricity.

Renewable Energy

Renewable energy sources were the first to be used historically, powering machines such as mills.

Water Wheel

A water wheel utilizes the energy of flowing water through a system of blades. It has various applications, such as grinding wheat to make flour.

• Wheels running low: These are the simplest type, with the bottom submerged. The force of the water current moves the wheel.
• Current average: This type of wheel is used when the current

Rigid Couplings

Rigid couplings are used when trees are on the same axis and do not change their position. There are several types:

• Flange Couplings: These are based on placing two flanges on the ends of the shafts so that when tightening the screws, the flanges are joined together.
• Clamp Couplings: These use a tapered internal conical piece that is compressed when tightening the screws, pressing the two pieces together.

Mobile Couplings

Mobile couplings are designed to accommodate some degree of misalignment or movement between shafts.

• Couplings with Gaskets: These absorb minor irregularities through elastic rotation and allow for very little misalignment.
• Universal or Cardan Joints: These transmit motion between two non-aligned trees.
• Homokinetic