Tuesday, July 31, 2007
In telegraphy and telephony a lightning arrester is to be found where wires enter a structure, preventing harm to electronic instruments within and ensuring the protection of individuals near them. Lightning arresters, also called rush protector, are devices which are linked between each electrical conductor in a power and transportation systems and the earth. These provide a short circuit to the earth that is interrupted by a non-conductor over which lightning jumps. Its function is to limit the rise in voltage when a connections or power line is struck by lightning.
The non-conducting substance may consist of a semi-conducting material like silicon carbide or zinc oxide, or a spark gap. Primitive varieties of such flash gaps are simply open to the air, but more modern varieties are filled with dry gas and provided with a little amount of radioactive material to support the gas to ionize when the voltage across the gap reaches a particular level. Other designs of lightning arresters use a glow-discharge tube associated between the protected conductor and ground, or any one of a many of voltage-activated solid-state switches called varistors or MOV's.
Lightning arresters built for substation use are consisting of a porcelain tube several feet in length and several inches in diameter, impressive devices, fill with disks of zinc oxide. A safety port is full on the side of the device to vent the occasional internal explosion without shocking the porcelain cylinder.
Tuesday, July 24, 2007
Hardware is the general name that is used to express physical body of a technology.It can be apparatus such as keys, hinge, locks, latches, wire, handles, corners, shackles, plumbing supplies, tools, cutlery, utensils, and machine parts, mainly when they are made of metal. In the
In a looser logic, hardware can be a major military equipment, or electronic equipment, or computer equipment. On the other hand, people don't talk about computer stores as "hardware supplies".In vernacular context, the term refers to trophies and other physical representations of award. The term "hardware" is used to specifically mean material or tangible parts of the computer when used in the context of computer systems and when compared to non-physical software running on the computer. Example: the CPU
Tuesday, July 17, 2007
Cultural differences make any worldwide definition of love hard to establish. Expressions of love may incorporate the love for a soul or mind, the love of laws and organizations, love for a body, love for natural world, love of food, love of money, love for learning, love of power, love of fame, love for the respect of others, etc. Different people place varying degrees of importance on the types of love they be given. Love is basically an abstract concept, easier to know-how than to make clear. Because of the difficult and non figurative nature of love, discourse on love is commonly reduced to a thought-terminating cliché, and there are a number of general proverbs concerning love, from Virgil's "Love conquers all" to The Beatles' "All you need is love".
Sunday, July 08, 2007
In a computer CPU, an accumulator is a register in which intermediary arithmetic and logic results are stored. Without a register like an accumulator, it would be necessary to write the result of each calculation (addition, multiplication, shift, etc.) to main memory, possibly only to be read right back again for use in the next operation. Access to main memory is slower than access to a register like the accumulator because the technology used for the huge main memory is slower (but cheaper) than that used for a register.
The canonical example for accumulator use is adding a list of numbers. The accumulator is initially set to zero, then each number in spin is added to the value in the accumulator. Only when all numbers have been added is the result seized in the accumulator written to main memory or to another, non-accumulator, CPU register.
Tuesday, July 03, 2007
Abstract art is now usually understood to mean art that does not depict objects in the natural world, but instead uses colour and form in a non-representational way.In the very early 20th century, the term was more often used to describe art, such as Cubist and Futurist art, that depicts real forms in a simplified or rather reduced way—keeping only an allusion of the original natural subject. Such paintings were often claimed to capture amazing of the depicted objects' immutable intrinsic qualities rather than its external appearance. The more precise terms, "non-figurative art," "non-objective art," and "non-representational art" avoid any possible ambiguity.