E-mail archiving is the process of systematically recording and saving copies of e-mail correspondence for records keeping and documentation purposes. Rationale for E-Mail Archiving From the legal standpoint, regulations governing records keeping and management have been around for years, with specific industries (e.g., lawyers, financial and credit institutions, medical facilities, etc.) being required to keep records for periods lasting from three to five years or more. The introduction and subsequent growth of internet-based communications has not changed the legal framework and requirements for these. At the same time, US courts Read More

Diffie-Hellman is an asymmetric cipher defined in U.S. Patent 4,200,770 in 1977, the same year that IBM’s algorithm was selected as the Data Encryption Standard. The Diffie-Hellman patent expired on 6 September, 1997. The Diffie-Hellman algorithm is named after its creators: Whitfield Diffie and Martin Hellman. ElGamal is a variant of Diffie-Hellman which was invented by Taher Elgamal.      

The hard drive found in most modern computers is large enough to hold a vast stockpile of files of various types. When transferring these files through uploads, email attachments, or by other means, however, the user may encounter file size limits. To counter this drawback, the user can take advantage of a number of file compression and file archiving programs that are able to compress files into a much smaller amount of virtual memory while maintaining the file structure and contents. The following is a list of file compression software. Read More

An Ethernet crossover cable can be used to directly connect two network devices through Ethernet. These can either be single computers or they can be networks. Ethernet crossover cables are commonly used for temporarily networking two devices in the absence of a network router, switch, or hub. The principle is the same, but the connection speeds and methods are different. The crossover cable’s function is to send and receive data. Ethernet crossover cables enable complex data transfers between computers, routers, and networks. Unlike standard Ethernet cables, the internal wiring of Read More

An amplifier uses a small input signal to create a large output signal, while minimizing distortion of the waveform. Amplifiers are used for both electrical and optical signals. Working of an Amplifier Modern amplifiers use solid-state electronics, although some are still made with vacuum tubes. A basic amplifier can be made with transistors, while complex amplifiers use other components, like op-amps, for feedback correction. To reduce the electrical noise, most amplifiers use toroidal transformers for their power supply. Features of an Amplifier The important features of an amplifier are its Read More

DNS (Domain Name System) servers are designed to allow networked devices such as computers, phones, and other servers to look up address records in DNS tables. The majority of DNS servers are configured to provide service to the organizations or people that own or pay service fees for the hardware. There are a number of public DNS servers that will provide DNS resolutions for requesting computers or people. The majority of these servers are purposely public; however, some become public due to misconfiguration or malicious behavior. These typically get fixed Read More

Potassium dichromate (K2Cr2O7) is an inorganic chemical reagent that is normally used as an oxidizer in industrial and laboratory applications. It is used to oxidize alcohols and convert primary alcohols to aldehydes and sometimes carboxylic acids. Unlike similar processes that use permanganate, only carboxylic acids result. The secondary alcohols are converted into ketones and no further oxidation is required. Potassium dichromate does not oxidize tertiary alcohols. The chemical is potentially harmful to human health and is a crystalline ionic solid that is a bright, red-orange color. Potassium Dichromate Uses When Read More

Vector images are a collection of individual objects rather than picture elements. A vector image can be composed of points that lines connect or nodes (control points) that Bezier curves connect. Vector Images: Advantages A mathematical equation defines each object inside a vector image. This means that vector images are not resolution dependent. Thus, each vector object is scalable and can generally be resized without any image quality loss. As such, vector images are ideal for graphics such as maps and company logos that often require scaling. However, it must Read More

MagLev Trains are trains that rely on magnets or magnetic force to run. There are different kinds of MagLev Trains that have been developed and they differ on the technology used to attract the magnetic force or magnets to make the train run or levitate. Each project is developing its own version of Magnetic levitation but the main difference rests on the way the magnetic field is generated. The German model and the Japanese HSST (High Speed Surface Transport) use Electromagnetic Suspension (EMS). China in its Shanghai Maglev uses German Read More

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