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

8.5 Dynamic Memory with Reservation — 8.5.1 General Features

Dynamic memory is essential for managing dynamic structures like lists, trees, and graphs. It's heavily used in object-oriented programming, where each object resides in the heap.

Key heap operations include allocation (e.g., malloc in C, new in C++) and deallocation (e.g., free in C, delete in C++). These operations are handled by a dedicated library that manages dynamic memory.

Allocation involves assigning a memory block of a specific size. Deallocation frees a memory block, allowing its reuse for future allocations. Effective heap management requires techniques to optimize space usage and the execution time of allocation and deallocation operations.

8.5.2 Fixed-Length Blocks

In this... Continue reading "Dynamic Memory Management: Strategies and Techniques" »

Storage Units: Definition and Types

Item 10: Storage units are those that can permanently store data or programs. They allow modification and re-saving of data for later retrieval. Central microcomputer equipment always includes a hard disk drive and a CD drive. The IDE interface for hard disks and CD/DVD drives is the most commonly used. Motherboards typically have two connectors to connect up to four devices. The SCI interface, used in professional equipment, is currently seeing less use due to the steady growth in flash drive storage capacity.

Physical and Logical Structure of Storage

Storage structure is divided into two parts:

• Physical Structure: This refers to how the storage medium is divided and corresponds to where the information is

Materiais Téxtiles

Os materiais téxtiles poden ser naturais ou sintéticos. As fibras naturais extráense de materias primas de orixe animal, vexetal ou mineral.

Fibras de Orixe Natural

Orixe Vexetal

Algodón: Provén do froito da planta do mesmo nome, da familia das malváceas. Aínda que a súa cor natural é branca, pode tinguirse de moitas cores. É elástico e flexible, bo illante térmico, resistente aos ácidos, lixeiro e permeable.

Liño: Obtense do talo da planta do mesmo nome, da familia das lináceas. A súa cor natural é branca ou castaña. É suave, flexible, bo condutor térmico e resistente ao cloro e á lixivia.

Esparto: Extráese das follas dunha planta herbácea. É moi resistente e tenaz. Emprégase na industria do calzado,... Continue reading "Propiedades e Aplicacións de Materiais Naturais e Sintéticos" »

KE-Jetronic Fuel Injection System

KE-Jetronic combines K-Jetronic and electronic control. It features an electrohydraulic flow injection system that adapts to engine operating states, enriching or leaning the fuel mixture as needed. Unlike some systems, it does not have a warming phase regulator. Key components include an engine temperature probe, a throttle butterfly switch, and a potentiometer within the flowmeter that determines the position of the plate probe.

L-Jetronic Fuel Injection System

L-Jetronic is a fully electronic system, characterized by intermittent and simultaneous fuel injection. Fuel volume is measured by a paddle-tube flowmeter. Fuel is metered by electromagnetic injectors. This system does not use a fuel distributor/doser.... Continue reading "Automotive Fuel Injection Systems: KE-Jetronic to MONO-MOTRONIC" »

ISDN: A digital network from start to finish, which allows integration of multiple services into a single access.
Network Terminal: It is a device that converts the 2 wires that come in 4 needed to communicate.
Access Basic: Contains 2 B channels (64 kbps data rate) and D (signaling speed 16 kbps).
Primary Access: 2048 kbps speeds. The entrance to the building is through radio links, fiber optic... Sometimes the B channel is called H.
Terminal Adapter (TA): Devices to work with old equipment (faxes) in an ISDN installation.
Doorman: In the installation of 1 keeper, 4 wires are needed to connect the housing with the street, or 3 if we combine the negative. To select the call, the plant must send a signal, for example, by the common negative.... Continue reading "Understanding ISDN: Key Components and Functionality" »

Home Utility Systems: Water, Gas, and Communications

These elements are responsible for the distribution and supply of water, energy, and communications throughout a home.

Water Supply and Distribution

The Water Cycle in a Home

The cycle involves sourcing from nature, followed by purification, and finally, consumption.

Domestic Water Network

This is the internal network that supplies hot and cold water to all necessary points in the house.

Key Components of the Water Network

• Valves: Open and close the passage of water in the pipes.
• Tanks/Reservoirs: Store a certain amount of water to prevent supply shortages.
• Faucets: Regulate the flow of water.
• Heaters: Supply Domestic Hot Water (DHW).
• Sanitary Fixtures: Used for personal hygiene and facilitate cleaning

Why are trials? 1) Identify properties of materials and determine their possible use 2) Quality control in manufacturing processes 3) Determine previous history and composition of materials 4) Establishing the causes of failure of the material in service 5) Study of new types of materials

Uniaxial tensile test: Performed with a standard specimen, a constant-load vellocidad and is a destructive test.

Hooke's law (elastic): ? _n = ? _n E · [MPa = 10 ⁶ N / m ² = kg / mm ^2]

E _{ceramic>metal} E> E _Polymer E ? ? ? ? ? Tfusion F _bond

Poisson's ratio: v =-? _lateral / _longitudinal ?

Yield strength: ? _and ? = 0.2 -> Polymers (? ? Max + min) / 2

Tensile strength (Rt): max. Rated voltage that supports the tensile specimen

Resistance to fracture:

DC Machine Types

Field or Parallel Shunt

• Field winding with many turns
• Small wire cross-section
• High resistance
• High inductance
• Field current is 1 to 4% of Inom

Field Series

• Low resistance
• Large cross-section
• Few turns
• Low inductance

Compound or Series and Parallel

• Part of the field is in series
• Low resistance
• Large cross-section
• Coils with few turns
• Low inductance

Independent Excitation

• Used for servo applications
• Auxiliary fields for weak-field switching
• Interpolate and is connected in series with armature
• Instability at high speeds
• Field-stabilizer used in shunting engines, connected in series with the armature

Control System

A control system is a device or group of devices used to control the operation of one or more electric machines.

Types of Diagrams

Connection

Electronic Communication Processes

In electronic communication, information in a signal moves from one device to another. Along the way, signals undergo a series of processes, including:

• Noise: The information signal gets mixed with other unwanted signals produced by highly diverse sources.
• Attenuation: This is the loss of energy a signal suffers as it propagates through a medium. This is resolved using amplifiers, repeaters, or signal regenerators at the transmitter and receiver.
• Signal Collision: A medium can be shared by several signals, but if they coincide, they collide and interfere with each other.

Denoising with Balanced Cables

This method consists of two conductors, where each carries the same signal but with opposite polarity to the other.... Continue reading "Signal Integrity in Guided Transmission Media" »

Technology, Materials, and Processes

Technology seeks to meet human needs by creating artificial objects. It involves the study of materials, technical skills, and work organization.

Materials are consumed in a process. They are used once and then depleted.

Tools are not consumed in a process. They can be used repeatedly and experience little to no depletion.

Inventing is creating an object for the first time.

Innovating is improving an object that already exists.

Discovering is finding something that existed but was previously unknown.

Craftsmanship involves creating objects with few or many people. These objects are unique because they are handmade with limited tools and tend to be expensive.

Industry involves many people, resulting in identical... Continue reading "Technology, Materials, and Processes: A Comprehensive Look" »