Data Center Security: A Comprehensive Guide
Data Center Security
Fire Safety
Dampers
Dampers at air vents and AC outputs shut down manually or automatically during fires, preventing the spread of fire, smoke, and fumes.
Fire Detectors
- Optical: Photoelectric technology generates a light beam. Smoke entering the detector obscures the beam, triggering the alarm.
- Ionic: Detect combustion particles. Smoke reduces air ionization, interrupting the current between electrodes and activating the alarm.
- Thermal: Trigger an alarm upon sudden temperature changes
Understanding Explosives: Types, Mechanisms, and Ignition
What is an Explosive?
An explosive is a material that undergoes rapid decomposition or oxidation when initiated by heat or electric shock. This process releases gaseous compounds that occupy a significantly larger volume than the original material. The rapid expansion displaces large volumes of air, creating a sonic boom due to the expansion rate exceeding the speed of sound.
Types of Explosives
High-Order Explosives
High-order explosives detonate. Detonation occurs only in high-order explosives and
Read MoreElectrical Cable Protection: Overcurrent, Overvoltage & Fault Detection
Protection Against Overcurrent and Overvoltage
The goal of protecting cables and limiting surge currents is to prevent them from exceeding their maximum allowable temperatures and to prevent potential fires.
Overloads
A facility or part of it is considered to be subject to an overload when, for some time, it is traversed by a current greater than the normal or assigned current, without any malfunction or failure in the installation. In short, the surge produces a reduction in the life of conductors.
Read MoreElectrical Installations in Homes and Buildings: A Comprehensive Guide
Electrical Installations in Homes and Buildings
Introduction
The increasing complexity of electrical installations in buildings requires professionals to consult regulations, standards, and manuals for practical application. This guide provides an overview of the main components of electrical installations in homes and buildings.
Parts of an Electrical Installation in a Home
The main parts include the service entrance, main panel, branch circuits, outlets, and fixtures. A sketch of a typical installation
Read MoreMaterials Science: A Comprehensive Guide
Alloys, Fluxes, and Steelmaking
What are the alloys and fluxes in the oven?
Fluxes remove slag, while ferroalloys improve steel properties.
Why can’t converters be added with pig iron and fluxes at the beginning?
Ferroalloys and fluxes would be removed with the initial slag.
What is the hottest part of the blast furnace where iron ore melts?
The bosh.
How is steel produced?
By blast furnace, furnace refining, and electric oven.
Blast Furnace Operation
Iron ore, fluxes, and coke are introduced. As they descend,
Read MoreHard Disk Drives and Storage Principles
Storage Principles
Magnetic Storage
Devices using this principle have a storage area consisting of many magnetic particles:
A particle oriented in one direction stores a logical 1, while another particle oriented in another direction stores a logical 0. These devices have read heads (a small coil of wire that when a current passes through it, creates a magnetic field that polarizes a point on the surface) and writing heads (the current in the coil comes from the own magnetic field of the magnetized
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