Notes, summaries, assignments, exams, and exercises for Technology for University

• Columns

  • Architectural Columns: An elongated vertical piece, typically circular, that supports the structure's weight and may have decorative purposes.
  • Isolated or Exempt Column: A column separated from a wall or other vertical building element.
  • Attached Column: A column juxtaposed with a wall or other building element.
  • Embedded Column: A column partially embedded in a wall or other part of the construction.

• Column Types by Stem

  • Smooth Column: A column without stretch marks or decorations.
  • Ribbed or Fluted Column: A column with ornamental striations and grooves along its length.
  • Fasciculated Column: A column comprised of a series of thin stems, grouped as a bundle.
  • Clustered Column: A column with several stems sharing a common capital and base.

• Special

The Optical System in a Mechanical-Optical Comparator

In a mechanical-optical comparator, the optical system is crucial for magnifying small displacements of a plunger or measuring contact. It projects the result onto a screen, allowing for easy and precise reading. The system generally includes several key components:

• A light source
• A mirror or prism
• A pivoted lever system
• A lens system
• A graduated scale or screen

How the Optical Comparator Works

When the plunger makes contact with the workpiece, any small displacement resulting from dimensional variation is transferred through a mechanical linkage (such as a lever). This movement causes a mirror or prism attached to the linkage to tilt. A beam of light is reflected by the mirror through the lens...

Turbojet Engine Fundamentals

A turbojet engine, as outlined in the EASA Part-66 Module 15 (Gas Turbine Engines) syllabus, is the simplest form of aircraft gas turbine engine. It generates all of its thrust through the high-speed ejection of exhaust gases from its nozzle. It is one of four main turbine engine types studied in the EASA syllabus: turbojet, turbofan, turboprop, and turboshaft.

Fundamental Principle

The turbojet operates on the Brayton cycle, which involves continuous intake, compression, combustion, and expansion. Air is compressed, mixed with fuel, burned at nearly constant pressure, and expelled at high velocity to produce thrust. The reaction of this high-speed exhaust jet propels the aircraft forward.

Construction and Components

Per...

#useradd nombredeusuario :: para crear usuarios

#passwd :: nombredelusuario

#groupadd :: nombredelgrupo :: (forma normal)

#groupadd -g 600 nombredelgrupo :: (guid sobre 650)

#userdel nombredelusuario :: para deletear usuarios

#groupdelnombredelgrupo :: borrar el grupo

#usermod -G nombredelgrupo nombredeusuario :: para asignar usuario a grupo.

opcion 2: editar archivo /etc/group -> grupo:x:600:usuarioqueseagregara

#nano /etc/shadow :: para poder ver los usuarios y poder bloquearlos

#passwd -l nombredeusuario :: para bloquear usuario

#passwd -u nombredeusuario :: para desbloquear usuario

#sudo passwd :: para cambiar la contraseña de root

# tail /etc/passwd :: paraver informacion de usuarios

#su nombredelotrousuario :: para iniciar sesion como el usuario...

1. Refer to the exhibit. The network administrator needs to setup Switch1 for remote access from HostA. Theshow ip interface brief is issued on Router1 and the show interfaces trunk command is issued on theSwitch1 to verify the current status. The administrator applies the additional configuration shown in theexhibit to Switch1. However, the telnet from HostA fails. What additional commands need to be appliedto the switch?
Switch(config)# interface vlan 10
Switch(config-if)# ip address 10.1.1.250 255.255.255.0
Switch(config-if)# no shutdown
Switch(config-if)# ip default-gateway 10.1.10.254

2. Refer to the exhibit. On the basis of the configuration shown, how will an Ethernet frame on port GigabitEthernet0/1 be modified?
802.1Q encapsulation inserts

Essential Steps for ATX Power Supply Repair

1 .- If the fuse is blown, replace it before you start measuring other diodes or the bridge rectifier. The diodes conduct current in one direction only. If reversing the ohmmeter leads shows continuity in both directions, they are shorted and should be replaced. Never solder a wire instead of a fuse; this will cause the power supply to deteriorate further.

Testing Switching Line Transistors

2 .- Continue by desoldering and measuring the transistor switching line input. Most of them are NPN; remember that when measuring base-collector or base-emitter junctions, they should conduct in one direction only. If they show very low resistance, they should be replaced. In the majority of power supplies, including...

Critical Path Method (CPM) and Program Evaluation and Review Technique (PERT)

Activity Duration and Delays

If an activity's slack (MTIJ) equals zero, any delay in this activity will delay subsequent activities. However, activities can not delay the project if MTIJ is greater than zero.

Critical Path

The critical path is the longest path, which represents the minimum time necessary to complete the project. Activities on the critical path are called critical activities.

Activities with Uncertain Duration

When the duration of activities is not known with certainty, three estimates are used: optimistic (a_ij), realistic (m_ij), and pessimistic (b_ij). It is assumed that the duration of activities follows a beta distribution. Assuming t_ij are independent...

Memory Hierarchy: Faster, Smaller, Costlier

The computer memory hierarchy organizes storage based on speed, size, and cost, moving from the fastest (CPU internal) to the slowest (external storage):

• Registers: CPU internal (Fastest, Smallest)
• Cache: L1, L2, L3 (Fast)
• Main Memory: RAM (DRAM)
• Secondary Storage: HDD, SSD
• Tertiary Storage: Optical, Tape (Slowest, Largest)

What Is Cache Memory?

Cache memory is a small, high-speed memory located close to the CPU. It stores frequently accessed data and instructions so the processor doesn’t have to fetch them repeatedly from slower main memory (RAM).

Cache significantly reduces memory access time, thereby improving overall system performance.

Why Cache Outperforms Main Memory (RAM)

Cache memory achieves superior...

Solid Bulk Terminals

As the name implies, solid bulk terminals handle bulk cargo and are typically located near port entrances.

Design

These terminals don't require a continuous berth. The current trend is to construct them with a light working platform.

Goods

Solid bulk terminals handle various goods, categorized as follows:

• Primary Bulk Cargo: Iron ore, cereals, coal, bauxite, and phosphates.
• Secondary Bulk Cargo: Metals, minerals for construction (coke, cast iron, cement, magnesium ore, scrap), and other agricultural products.

Storage

Storage methods depend on the cargo type:

• Clean Bulk: Products for human or animal consumption (cereals, flour, animal feed) require specific handling and storage facilities.
• Dirty Bulk: Materials from mining and steel

Moulds for Casting

Mould made of ceramic material e.g. sand particles, bound together with a BINDER which may be:

• Clay: 90% sand, 8% clay, 2% water - green sand mould.
• Thermosetting resin system - coat sand with two or more reactants which cure to form a resin (typically 1 - 2 parts binder to 100 parts sand):
  • Curing begins immediately components are combined, for a period of time after initial mixing the sand is workable and flowable to allow filling of mould - No bake systems.
  • Phenolic - urethane no bake is most common.
  • Curing occurs upon application of heat – heat cured binder system.
  • Liquid thermosetting binder and a catalyst are mixed with dry sand. Upon heating the catalyst releases acid which induces a rapid cure in 10 – 15 s. Pattern is