Stateful Packet Inspection is a dynamic packet filtering technique in which each data packet is assigned to a specific active session. The data packets are analyzed and the connection status is included in the decision. In this technique, which is used in firewalls, the data packets are analyzed during transmission on the switching layer (3rd layer of the OSI model) and stored in dynamic state … [Read more...]
How Packet Filter Works (iptables)
A packet filter, also known as a network filter, is an application or software that filters incoming and outgoing traffic on a computer network. This is usually to protect the network from attackers. Just as important as protection against external attackers is protection against unintentionally outgoing packets; This can make it more difficult, for example, for one's own computer to spread … [Read more...]
General Basics of Firewall
A firewall is a security system that protects a computer network or an individual computer from unwanted network access. More broadly, a firewall is also a sub-aspect of a security concept. Every firewall security system is based on a software component. Firewall software is designed to restrict network access based on the sender or destination and services used. It monitors the traffic passing … [Read more...]
Solar Cell Materials – An Overview
A solar cell (photovoltaic cell) is an electrical component that converts radiant energy, usually sunlight, directly into electrical energy. The application of the solar cell is photovoltaics, where it serves as a power source. The physical basis of the conversion is the photovoltaic effect, which is a special case of the internal photoelectric effect. There are many different cell types, which … [Read more...]
Construction of Solar (Photovoltaic) System
A photovoltaic system, also known as a PVA system or solar generator, is a solar power system in which part of the solar radiation is converted into electrical energy by means of solar cells. The typical direct type of energy conversion is called photovoltaics. In contrast, other solar power plants (e.g. solar thermal power plants) work via the intermediate steps of thermal energy and mechanical … [Read more...]
Technology Behind Supercapacitors
Supercapacitors, also known as ultracapacitors, are electrochemical capacitors and, as such, a further development of the Electric double-layer capacitor (EDLC). Compared to batteries of the same weight, supercapacitors have only about 10% of their energy density, but their power density is about ten to a hundred times greater. Supercapacitors can therefore be charged and discharged much … [Read more...]
Application of Resonant Circuit
An electrical resonant circuit is a resonant electrical circuit consisting of a coil and a capacitor that can perform electrical oscillations. The electric oscillating circuit is often compared to the harmonic oscillator of mechanics such as the spring pendulum or tuning fork. In this resonant circuit, energy is periodically exchanged between the magnetic field of the coil and the electric field … [Read more...]
Operation of Solar Inverters
Solar inverter refers to a special type of inverter that converts the DC voltage of the solar cells into alternating voltage and is optimized for operation with solar modules. This inverter is part of a photovoltaic system and has the task of feeding the electrical energy generated into the power grid. On the input side to the solar cells, there is usually a DC converter with a maximum power … [Read more...]
Application of Inverter
An inverter is an electrical device that converts direct current into alternating voltage. In addition to rectifiers, DC converters and converters, inverters form a subgroup of power converters. Depending on the application, inverters generate either a single-phase or multi-phase output current or a single- or multi-phase output voltage. The efficiency of semiconductor-based devices can reach up … [Read more...]
Required Professional Skills of a System Administrator
A system administrator or (informally) admin, sysadmin manages computer systems on the basis of broad access rights to the system. System administrators plan, install, configure, and maintain the information technology (IT) infrastructure of a company or other organizations. As operators, they carry out the manual activities required for the ongoing operation of the computer equipment. In many … [Read more...]
How to Install Apache and PHP on Ubuntu 22.04 Server
This guide is intended for operating a WordPress or similar PHP-MySQL-based application on a dedicated or cloud/VPS server with 12GB to 16 GB. You can use a server from any web host of your choice. We can suggest you use VPSDime OpenVZ instances for small to medium websites. 6GB RAM, 10Gbps connection instances will cost you $7.00/mo. If you need dedicated resources, then you can test their … [Read more...]