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

Mechanical Pump: Concept and Operation

The mechanical pump is the most used artificial lift method worldwide. This method consists of an underground pump with reciprocating action, which is supplied with power produced by a string of rebar. Energy comes from an electric motor or internal combustion engine, which mobilizes a unit area through a gear system and straps. The mechanical pump has its largest application in the global production of heavy and/or extra-heavy crudes, but is also used in the production of medium and light crudes.

Many theories explain the behavior of production wells by mechanical pumping. Some operators prefer to produce a coated pit open to the atmosphere and closed with the casing; this mechanism really depends on the... Continue reading "Mechanical Pumps: Concepts and Operation" »

Slag and pig iron pass through an LD converter for forming into steel ingots. Around this ring furnace, wind is extracted by hot air.

Operation of the Converter

The converter leans over the oven, and flux and sometimes cast iron scrap are added. It is then set to vertical, and a lance is lowered to inject oxygen into the molten metal. The impurities are burned. The converter leans out of the furnace, and the slag that floats on the steel is poured over the spoon. Alloys and carbon are added.

Obtaining Steel Through Scrap

To convert scrap steel, an electric oven is used. Its most important parts are:

• Electric transformer: Transforms alternating current to direct current and voltage to 900V.
• Arms of the electrodes: The electrodes can approach or move

Each face of the plate or disk surface is divided into a number of concentric rings, called tracks. The number of these tracks depends on the sensitivity of the mechanical parts inside the disk.

Each track is numbered from zero, increasing as we move towards the center of the disc.

Speaking of tracks also means talking about cylinders. The number of tracks per surface equals the number of cylinders. If the positioning arm is on a certain track, it is on the same track on all disks, and the set of all those tracks is called a cylinder.

The tracks are divided into sectors, which hold the same amount of data (512 bytes). However, these tracks do not always have the same number of sectors. This depends on the length of the track. For example, the... Continue reading "Hard Drive Structure: Tracks, Sectors, and Logical Organization" »

Essential Home Utilities: Installation and Maintenance

Water Systems

Facilities housing installations:

• Water: Cold water, hot water, and sewerage inside.
• Electrical: Lighting, electrical outlets, and other electrical needs.
• Gas: Kitchen, heater, and boiler.
• Heating: Radiators, heat pump, underfloor heating, and air conditioning.
• Other: Phone, antenna, elevator, electric doorman, alarm, and surge protection.

Drinking water is suitable for consumption and produces no alterations in the body.

The installation of water in a home consists of:

• The water supply network.
• The sewerage system for sewage and rainwater.

The water network is the plumbing system that allows the internal hot and cold water supply to all parts of the house where necessary. The network... Continue reading "Essential Home Utilities: Water, Gas, and Electrical Systems" »

Understanding Electric Circuits

An electric circuit is a path through which electrons flow. It typically consists of a generator, a wire conductor, a switch, and a receiver.

Electric Current

Electric current refers to the flow of electrons around a circuit.

Electrical Conductivity

Electrical conductivity depends on the atomic structure of each material:

• Conductors: Allow electric currents to pass through them. All metals are good conductors.
• Insulators: Do not allow electric currents to pass through them (e.g., wood, glass, plastic, air).
• Semiconductors: Have properties between conductors and insulators (e.g., silicon, germanium).

Electrical Resistance

Electrical resistance of a material is a measure of the degree to which the material opposes an electric... Continue reading "Understanding Electric Circuits: Components and Principles" »

Cable Testing Phase Continuity and Order

Checking Cable Continuity

To ensure cable continuity, form a loop bridging two phases at one end. Connect the other end to an isolation and tension meter. Test the continuity of the three possible loops, including one to neutral.

A high impedance reading indicates a discontinuity in the cable.

Verifying Phase Identification

To identify phases, ground one phase at one end of the wire. At the other end, connect an isolation meter between each conductor and ground, applying 500V successively. The lowest of the four measurements corresponds to the same conductor on both ends.

Dielectric Strength Test: Low Voltage Cable Insulation

The risk of damaging a new cable depends on the discharge time constant. Never discharge... Continue reading "Cable Testing and Maintenance: Ensuring Network Reliability" »

Metalworking Processes and Techniques

Casting Process

Casting consists of introducing molten metal into a container with an internal cavity called a mold. Molds can be manufactured from steel or foundry sand.

1. The metal is heated in an oven until it melts.
2. The liquid metal is poured inside the mold.
3. It is cooled until the metal solidifies.
4. The solidified part is removed from the mold.

Material Handling

These techniques are carried out with tools and machine tools using prefabricated materials such as bars, rods, plates, etc.

Marking Tools

• Punch
• Scriber
• Dividers

Cutting Techniques and Tools

• Sheet metal shears or snips
• Guillotine
• Press and die cut
• Hacksaw

Circular Saw

A machine tool mainly used for cutting large boards or plates. It can make straight and oblique... Continue reading "Metal Fabrication Methods" »

Structured Cabling in Multi-Story Buildings

The layout is somewhat complex when covering large areas, such as multi-story buildings. In this sense, we must consider the design constraints imposed by the Local Area Network (LAN) technology you wish to implement:

• Network traffic segmentation.
• Maximum length of each network segment.
• Presence of electromagnetic interference.
• Need for Virtual Local Area Networks (VLANs).
• Etc.

Apart from these constraints, the concept of structured cabling is simple:

• Route cables on each floor.
• Interconnect cables from each floor.

Horizontal Cabling: Floor Distribution System

All cables are concentrated in the **floor distribution cabinet** (also known as a **telecommunications closet**). This cabinet serves as a frame where... Continue reading "Structured Cabling Design for Large Buildings" »

6 º Terminal Operator

The 6th terminal operator is the most difficult to handle due to the variety of services offered, traffic channels, and call distribution. It has a greater number of function keys, other terminal extensions, and a large display that takes advantage of the exchange. It came with the PBX to manage the exchange well and has a higher cost than any other type of terminal. It did not exist in KTS systems.

7 º Architecture services of a PABX and block diagram

Services architecture in a private digital exchange:

Usual ports Specifications:

Basic System:

• Two gateways T.
• Two ports S.
• Two analog extension ports / b.
• Eight proprietary extension ports.

Through expansion units:

• A link port T.
• Three-port S.
• Four link ports a / b.

Units options:

• Intercom

Hydrogen Fuel: Pros and Cons

Evaluating the use of hydrogen produced from conventional sources reveals several advantages and disadvantages:

Advantages

• Clean energy vector: Its use does not directly emit greenhouse gases into the atmosphere.
• Synergies with Renewables: Partnerships with renewable energy sources (like wind) could create important synergies, helping manage intermittency.
• High Power-to-Weight Ratio: Hydrogen possesses the highest power-to-weight ratio among known fuels.
• Efficiency: The efficiency of processes involving hydrogen can be higher than those using other fuels.
• Safety Aspects: While requiring careful handling due to low ignition energy, it is non-toxic and disperses quickly if leaked. Flammability limits differ from other fuels.