Notes, abstracts, papers, exams and problems of Technology

Teen Room Essentials

Furniture

• Chest of drawers: A piece of furniture with drawers in which you keep things such as clothes.
• Cushion: A bag made of cloth, plastic, or leather that is filled with soft material, often has an attractive cover, and is used especially on chairs for sitting or leaning on.
• Duvet: A quilt, often with a removable cover; comforter.
• Wardrobe: A tall cupboard in which you hang your clothes.

Room Atmosphere

• Dimly-lit: Describing the way a room is lit when there's only a small amount of light.
• Restful: Used to describe something that produces a feeling of being calm and relaxed.

Social Dynamics

• Alter: To change, or to make someone or something change.
• Compromise: The act of agreeing to something that is not exactly what you want in

Properties of Metals

PROPERTIES OF METALS: good electrical, thermal and acoustic conductors; ductile and malleable; tough; they melt at high temperatures, expand when the temperature rises and contract when it cools; some are magnetic; rust when they come into contact with air and oxygen (not all); can be recycled and reused, some are toxic for the environment.

Ferrous Metals

FERROUS METALS: main component is iron.

PURE IRON: greyish white colour, good magnetic properties. Disadvantages: only melts at high temperature, difficult to machine, fragile and brittle. Uses: rarely used, used in electronics and electrical components. CAST IRON: very hard and resistant. Uses: machine parts, casing for engines, stands for machines, pistons, street lamps,... Continue reading "Properties of Metals and Ferrous vs. Non-Ferrous Metals" »

Function Definition

A function definition in C++ consists of the statements that constitute a function. It includes:

• Name: The identifier of the function.
• Parameter List: Variables enclosed in parentheses that hold values passed to the function.
• Body: Statements within curly braces that perform the function's task.
• Return Type: The data type of the value the function returns (e.g., int, double, void if no value is returned).

Function Header

The function header declares the function. It consists of:

• Return Type
• Name
• Parameter List

For example: void evenOrOdd(int num). Note that there is no semicolon at the end of the header.

Function Return Type

• If a function returns a value, the return type must be specified (e.g., int main()).
• If a function doesn't return

Circulator

A nonreciprocal device, means transfer function cannot be calculated inverse (output to input). The characteristic of this device depends on which direction the applied signal. It is based on magnetic ferrite and uses a ferrite core.

MW Semiconductor Devices

• Diodes: can be used for detecting MW signals. (Until the 1960s).
• -Schottky pin diodes are passive. Varactor, tunnel are active diodes. Gun impatt, trapatt. You can't use diodes with wires because this wire becomes inductive and stops MW signal. Connect diode chips with wire bonds (without connectors.)
• Schottky barrier diode: there are no minority carriers, so there is no delay (only majority). The operation speed is high, so it can be used in MW applications as a detector.

Cutoff Frequency

Home Automation and Telecommunication

Home Automation

Home Automation refers to the use of computer and information technology to control a home. This includes various aspects such as:

• HVAC (Heating, Ventilation, and Air Conditioning): Controls the temperature and air quality in your home.
• Lighting: Allows you to control lights remotely and automate lighting schedules.
• Intercom: Enables communication within the home or with visitors at the door.
• Smart Window: Windows that can be automatically tinted or adjusted for optimal energy efficiency.
• Video Door Phone System: Allows you to see and communicate with visitors at your door remotely.
• Socket: Smart sockets that can be controlled remotely and monitor energy usage.
• TV Set: Integration with smart TVs

¡Escribe tu texto aquí!the gears or sprockets are mechnical elements designed to trasmite turning movements 

parallel circuits

• Rock wool• Glass wool

Divided according to material density to: – very light products (density < 50 kg/m3); – light (density from 50 kg/m3 to 200 kg/m3 ); – heavy (density From 200 kg/m3 to 400 kg/m3 ).

According to compressibility (material affected by 2 kPa load) into: – Soft (compresses more than 30 %); – half rigid (compresses from 6 to 30 %); – Rigid (compresses not more than 6 %).

according to usage for constructions into: – general purpose: • not Withstanding loads (light carcass type) • Withstanding loads (molded concrete Floors) in constructions – outer walls; – flat roofs.

Raw material type is chosen depending on resistance to temperature (basalt wool from 1000ºC, dolomite wool 650ºC, glass 550ºC), fiber... Continue reading "Air law" »

Mechanisms

A mechanism is a group of elements that transmit and transform forces and movements from a motive (or driver) element to a receptor (or driven) element. Mechanisms allow us to perform operations more easily and with less effort.

Classification of Mechanisms

• Movement Transmission Mechanisms
  • Linear Transmission (e.g., pulleys, levers)
  • Circular Transmission (e.g., friction wheels, pulleys and belts, gears, chain drives)
• Movement Transformation Mechanisms (e.g., rack and pinion, handle-winch, crank-connecting rod, cam and eccentric)

Lever

A lever is a rigid bar that pivots around a fixed point called a fulcrum. It is used to amplify force, allowing a larger force to be overcome with a smaller effort. However, to achieve this force multiplication,... Continue reading "Mechanisms: Levers, Pulleys, Gears, and More" »