Tuesday, July 31, 2007

Headphones

Headphones are a pair of small loudspeakers, or less commonly a single speaker, with a way of holding them close to a user's ears and a means of linking them to a stereophonic or monophonic audio-frequency signal source such as an audio amplifier, radio, etc. In the context of telecommunication, the term headset is used to describe a combination of
Headphone and microphone used for two-way communication, for example with a telephone.

Sunday, July 22, 2007

Metal

In chemistry, a metal is a ingredient that readily loses electrons to form positive ions and has metallic bonds between metal atoms. Metals form ionic bonds with non-metals. They are sometimes described as a web of positive ions surrounded by a cloud of delocalized electrons. The metals are one of the three groups of elements as eminent by their ionization and bonding properties, along with the metalloids and nonmetals. On the periodic table, a diagonal line drawn from boron separates the metals from the nonmetals. Most elements on this line are metalloids, sometimes called semi-metals; elements to the lower left are metals; elements to the upper right are nonmetals.

Friday, July 13, 2007

Vegetable

Vegetable is a culinary term which usually refers to an edible part of a plant. The definition is traditional rather than scientific and is somewhat capricious and subjective. All parts of herbaceous plants eaten as food by humans, entire or in part, are normally considered vegetables. Mushrooms, though belonging to the biological realm fungi, are also commonly considered vegetables. In general, vegetables are thought of as being savory, and not sweet, even though there are many exceptions. Nuts, grains, herbs, spices and culinary fruits (see below) are usually not considered vegetables.

Sunday, July 08, 2007

Extranet

An extranet is a personal network that uses Internet protocols, network connectivity, and possibly the public telecommunication system to securely share part of an organization's information or operations with suppliers, vendors, partners, customers or other businesses. An extranet can be viewed as part of a company's Intranet that is extended to users outside the company. It has also been described as a "state of mind" in which the Internet is professed as a way to do business with other companies as well as to sell products to customers.

Sunday, July 01, 2007

Lopping

Lopping, also known as tree lopping and topping, is the practice of cutting trunks and branches of a tree in an effort to contain the tree's size or shape. Lopping is differentiated from other styles of pruning by where the cuts are made. When a tree is lopped, the cuts are made internodally, or not at branch unions and collars at the correct angles, leaving a piece of protruding timber that is called a stub.
Lopping in many cases is careful an inappropriate pruning method for amenity trees. The lopped stubs may regrow adventitious epicormic shoots which are bonded only to the bark. These epicormic shoots can grow dynamically and, unless regularly pruned off, may outgrow the original height and spread of the tree. Further, the ends of the lopped stubs are exposed to pathogens which may enter and infect the tree.
In orchards, fruit trees are often lopped to encourage regrowth and to keep a smaller tree for ease of picking fruit. The pruning regime in orchards is more intended and the productivity of each tree is an important factor. In an orchard, though, the natural longevity of a tree is often compromised in favor of its output in fruiting. Orchard trees are also carefully monitored and treated with fungicides and insecticides to minimise losses.

Tuesday, June 26, 2007

Superscalar

A superscalar CPU architecture implements a form of parallelism called Instruction-level parallelism within a solitary processor. It thereby allows faster CPU throughput than would otherwise be possible at the same clock rate. A superscalar architecture executes more than one instruction during a single pipeline stage by pre-fetching several instructions and at the same time dispatching them to redundant functional units on the processor.

History

Seymour Cray's CDC 6600 from 1965 is often mentioned as the first superscalar plan. The Intel i960CA and the AMD 29000-series 29050 microprocessors were the first commercial single-chip superscalar microprocessors. RISC CPUs like these brought the superscalar idea to micro computers because the RISC design results in a simple core, allowing straightforward instruction send off and the inclusion of multiple functional units on a single CPU in the inhibited design rules of the time. This was the reason that RISC designs were faster than CISC designs through the 1980s and into the 1990s.

Saturday, June 23, 2007

Tide

Tides are the cyclic rising and falling of Earth's ocean surface caused by the tidal forces of the Moon and the sun acting on the oceans. Tides cause changes in the depth of the marine and estuarine water bodies and produce oscillating currents known as tidal streams, making prediction of tides important for coastal navigation. The strip of seashore that is submerged at high tide and exposed at low tide, the intertidal zone, is an important ecological product of ocean tides
The changing tide produced at a given location is the result of the changing positions of the Moon and Sun relative to the Earth coupled with the effects of Earth rotation and the local bathymetry.Sea level measured by coastal tide gauges may also be strongly affected by wind. More generally, tidal phenomena can occur in other systems besides the ocean, whenever a gravitational field that varies in time and space is present

Sunday, June 17, 2007

Industrial metal

Industrial metal is a musical genre which draws elements from industrial music and heavy metal music. Industrial metal music is typically centered around metal guitar riffs and industrial synthesizer/sequencer lines, heavily distorted, very low pitched guitars, as well as harsh vocals, but in some instances can have clean vocals. This term is used quite loosely, telling everything from industrial bands sampling metal riffs to heavy metal groups augmented with sequencers. Industrial metal encompasses industrial subgenres such as aggro-industrial and coldwave and often overlaps some elements of nu-metal and post-punk.
It is difficult to distinguish many industrial metal artists and industrial rock because both genres leave much room for ingenuity and creativity. By convention, all industrial metal artists may be more vaguely described as industrial rock as well, but not all industrial rock artists are properly described as industrial metal. The general rule of thumb is the speed and "crunchiness" of the guitars. If the guitars are fast and heavily distorted, it is likely industrial metal.

Monday, June 11, 2007

USB Drives

USB drives mean Universal Serial Bus. USB flash drives also known as USB drives, key drives, pen drives or thumb drives. USB drives are NAND-type flash memory data storage devices incorporated with a USB interface. They are typically small, lightweight, detachable and rewritable. As of April 2007, memory capacities for USB Flash Drives currently are sold from 32 megabytes up to 64 gigabytes .Capacity is limited only by current flash memory densities, although cost per megabyte may increase quickly at higher capacities due to the expensive components.

USB flash drives offer possible advantages over other portable storage devices, particularly the floppy disk. They are more compact, generally faster, hold more data, and are more consistent than floppy disks. These types of drives use the USB mass storage standard, supported natively by recent operating systems such as Linux, Mac OS X, UNIX, and Windows.

Wednesday, June 06, 2007

Prawn

Prawns are shrimp-like crustaceans, belonging to the sub-order Dendrobranchiata .Prawns are illustrious from the superficially similar shrimp by the gill structure which is branching in prawns, but is lamellar in shrimp. The sister taxon to Dendrobranchiata is Pleocyemata, which contains all the true shrimp, crabs, lobsters, etc.
In various forms of English, the name "prawn" is often applied to shrimp as well, generally the larger species, such as Leander serratus. In the United States, according to the 1911 Encyclopedia, the word "prawn" usually indicates a freshwater shrimp or prawn. In Middle English, the word "prawn" is recorded as prayne or prane; no cognate form can be found in any other language. It has often been connected to the Latin perna, a ham-shaped shellfish, but this is due to an old scholarly error that linked perna and parnocchie with prawne-fishes or shrimps. In fact, the Old Italian perna and pernocchia meant a shellfish that yielded nacre, or mother-of-pearl.

Sunday, May 27, 2007

Uses for chain

Exact uses for chain include: Bicycle chain, chain that transfers power from the wheel to the
drive-wheel of a bicycle thus propelling it Chain drive, the main feature which differentiated the safety bicycle Chain gun, type of machine gun that utilizes a chain, driven by an external power source, to actuate the mechanism rather than using recoil Chain pumps, type of water pump where an endless chain has positioned on it circular discs Chain-linked Lewis, lifting device made from two curved steel legs Chainsaw, portable mechanical, motorized saw Curb chain, used on curb bits when riding a horse Keychain, a small chain that connects a small item to a key ring Lead shank, used on difficult horses that are misbehaving O-ring chain,

a specialized type of roller chain Roller chain, the type of chain most commonly used for transmission of mechanical power on bicycles, motorcycles, and in industrial and agricultural .machinery Snow chains, used to improve traction in snow Timing chain, used to regulate the valve and ignition timing on an internal combustion engine Ball and chain, phrase that can refer to either the actual restraint device that was used to slow down prisoners, or a derogatory description of a person's significant other Bicycle lock, lockable chain.

Saturday, May 19, 2007

Content Management System

A Content Management System is a software system intended for content management. This includes computer files, image media, audio files, electronic documents and web content. The idea behind a Content Management System is to make these files available inter-office, as well as over the web. A Content Management System would most often be used as archival as well. Many companies use a Content Management System to store files in a non-proprietary form. Companies using a Content Management System file share with ease, as most systems use server based software, even further broadening file availability. As shown below, many Content Management Systems include a feature for Web Content, and some have a feature for a "workflow process."

"Workflow" is the idea of moving an electronic document along for either approval, or for adding content. Some Content Management Systems will simply facilitate this process with email notification, and automated routing. This is ideally a mutual creation of documents. A Content Management System facilitates the organization, control, and publication of a large body of documents and other content, such as images and multimedia resources.

Monday, May 14, 2007

Biography

Biography is a type of literature and further forms of media such as film, based on the written accounts of individual lives. While a biography may focus on a subject of fiction or non-fiction, the term is frequently in reference to non-fiction. Pat Shipman however, says "I think a good biographer has to write fiction some of the time to make apparent a significant event in someone's life." This is sometimes debated. As opposed to a profile or curriculum vitae, a biography develops a complex analysis of personality, highlighting different aspects of it and including intimate details of experiences. A biography is more than a list of distant facts like birth, education, work, relationships and death. It also delves into the emotions of experiencing such events.

Ancient Greeks developed the biographical tradition which we have inherited, although until the 5th century AD, when the word 'biographia' first appears, in Damascus' Life of Isodorus, biographical pieces were called simply "lives" . It is quite likely that the Greeks were drawing on a pre-existing eastern tradition; certainly Herodotus' Histories contains more exhaustive biographical information on Persian kings and subjects than on anyone else, implying he had a Persian source for it.

Wednesday, May 09, 2007

History of bridges

The initial bridges were spans made of made of wood logs or planks and eventually stones, using a easy support and crossbeam arrangement. Most of these early bridges were very poorly built and could not often support heavy weights. It was this insufficiency which led to the development of better bridges. The arch was first used by the Roman Empire for bridges and aqueducts, some of which still situate today. These arch based bridges could stand in circumstances that would previously have swept any bridge away. An example is the Alcantara Bridge, built over the river Tagus.
Earlier bridges would have been swept away by the strong current. The Romans also used cement, which reduced the difference of strength found in natural stone. One type of cement, called pozzolana, consisted of water, lime, sand, and volcanic rock. Brick and mortar bridges were built after the Roman era, as the skill for cement was lost then later rediscovered. Rope bridges, a simple type of suspension bridge, were used by the Inca civilization in the Andes Mountains of South America, just prior to European colonization in the 1500s.During the 18th century there were many innovations in the design of timber bridges by Hans Ulrich, Johannes Grubenmann, and others. The first engineering book on building bridges was written by Hubert Gautier in 1716.

With the Industrial Revolution in the 19th century, truss systems of shaped iron were developed for larger bridges, but iron did not have the tensile strength to support large loads. With the advent of steel, which has a high tensile strength, much larger bridges were built, many using the ideas of Gustave Eiffel.

Friday, April 27, 2007

Biography

Biography (from the Greek words bios meaning "life", and graph in meaning "write") is a type of literature and further forms of media such as film, based on the written accounts of individual lives. While a biography may focus on a subject of fiction or non-fiction, the term is frequently in reference to non-fiction. Pat Shipman however, says "I think a good biographer has to write fiction some of the time to make apparent a significant event in someone's life." This is sometimes debated. As opposed to a profile or curriculum vitae, a biography develops a complex analysis of personality, highlighting different aspects of it and including intimate details of experiences. A biography is more than a list of distant facts like birth, education, work, relationships and death. It also delves into the emotions of experiencing such events.

Ancient Greeks developed the biographical tradition which we have inherited, although until the 5th century AD, when the word 'biographic' first appears, in Damascus' Life of Isodorus, biographical pieces were called simply "lives" ("bioi"). It is quite likely that the Greeks were drawing on a pre-existing eastern tradition; certainly Herodotus' Histories contains more exhaustive biographical information on Persian kings and subjects than on anyone else, implying he had a Persian source for it.

Tuesday, April 24, 2007

Groundwater

100 Groundwater is water flowing within aquifers below the water table. Within aquifers, the water flows through the pore spaces in unconsolidated sediments and the fractures of rocks. Groundwater is recharged from, and ultimately flows to, the surface naturally; natural discharge often occurs at springs and seeps and can form oases or swamps. Groundwater is also often withdrawn for agricultural, municipal and industrial use through man-made wells. The study of the giving out and movement of groundwater is hydrogeology.


Relative groundwater travel times, click to view full size Groundwater can be a long-term 'reservoir' of the natural water cycle, as opposed to short-term water reservoirs like the atmosphere and fresh surface water. The figure shows how deep groundwater can take a very long time to complete its natural cycle. Groundwater is naturally replenished by surface water from precipitation, streams, and rivers when this recharge reaches the water table. It is estimated that the volume of groundwater is fifty times that of surface freshwater; the icecaps and glaciers are the only larger reservoir of fresh water on earth.

Usable groundwater is contained in aquifers, which are subterranean areas of permeable material that channel the groundwater's flow. Aquifers can be confined or unconfined. If a confined aquifer follows a downward grade from a recharge zone, groundwater can become pressurized as it flows. This can create artesian wells that flow freely without the need of a pump. The top of the upper unconfined aquifer is called the water table or paretic surface, where water pressure is equal to atmospheric pressure.

Wednesday, April 18, 2007

Mobile phone

A mobile phone or cell phone is an electronic telecommunications device. Most current mobile phones connect in its place to the network using a wireless radio wave transmission technology. These mobile phones communicate via a cellular network of base stations, which is in turn connected to the conventional telephone network. In the late 1970s and early 1980s the car phone was the only mobile phone available.In addition to the standard voice function of a telephone, a mobile phone can support many additional services such as SMS for text messaging, packet switching for access to the Internet, and MMS for sending and receiving photos and video.Some of the world's largest mobile phone manufacturers include Alcatel, Audiovox, Fujitsu, Kyocera, LG, Motorola, NEC, Nokia, Panasonic, Philips, Sagem, Samsung, Sanyo, Sharp, Siemens, SK Teletech, Sony Ericsson, and Toshiba.There are also specialist communication systems linked to, but distinct from mobile phones, such as satellite phones and Professional Mobile Radio. Mobile phones are also separate from cordless telephones, which generally operate only within a limited range of a specific base station.

Monday, April 09, 2007

Bonneville Dam

100 Bonneville Lock and Dam consists of a number of dam structures that together whole a span of the Columbia River between the US states of Oregon and Washington at River Mile 146.1. The dam is situated 40 miles east of Portland, Oregon, in what is now the Columbia River Gorge National Scenic Area. The main functions of Bonneville Lock and Dam are those of electrical power generation and river navigation. The dam was built and is managed by the US Army Corps of Engineers. Electrical power generated at Bonneville is spread by the Bonneville Power Administration. Bonneville Lock and Dam are named for Army Capt. Benjamin Bonneville, an early explorer endorsed with charting much of the Oregon Trail. The name is marked BAH-nee-vill.
History
The unusual structures: a lock and powerhouse constructed on the south side of Bradford Island and a spillway on the north side were built by the Army Corps of Engineers during the New Deal—started in 1933 and finished in 1937. Prior to this damming of the river, a set of locks that were opened in 1896 moved ships around Cascades Rapids, situated several miles upstream of Bonneville. Both the cascades and the old lock structure were submerged by Lake Bonneville, the tank that formed behind the dam. The original navigation lock at Bonneville was opened in 1938 and was, at that time, the biggest single-lift lock in the world.
Dimensions and statistics
Aerial view of spillway flanked by powerhouses, Bonneville Lock and Lake Bonneville beyond First Powerhouse – Constructed in 1933-37; 313 m long; 10 generators with an output capacity of 526,700 kW.
Spillway – Constructed 1933-37; 18 gates over a length of 442 m; maintains the reservoir usually 18 m above the river on the downstream side;
Second Powerhouse – Constructed 1974-81; 300.5 m long; 8 generators with a total generating capacity of 558,200 kW.
Bonneville Lock – Constructed in 1993 at a cost of $341 million; 26 m wide, 206 m long; transit time is approx. 30 minutes.
Lake Bonneville – 77 km long reservoir on the Columbia River created by Bonneville Dam; part of the Columbia-Snake Inland Waterway.

Monday, April 02, 2007

Goshawk

The Goshawk is a average large bird of prey in the family Accipitridae which also includes many other diurnal raptors such as eagles, buzzards and harriers.

It is a extensive species throughout the moderate parts of the northern hemisphere. In North America it is named as the Northern Goshawk. It is mostly resident, but birds from colder regions of north Asia and Canada wander south for the winter.


Goshawk in flight this kind nests in trees, building a new nest each year. It hunts birds and mammals in woodland, relying on surprise as it flies from a perch or hedge-hops to cruel circle its prey unaware. Animals as large as hares and Pheasant are taken. Its call is a ferocious shriek. Many older goshawks refuse to attack hares, if it was previously acutely kicked by a hare which it tried to catch.


In Eurasia, the male is confusable with a female Sparrow hawk, but is larger, much bulkier and has comparatively longer wings. In spring, he has a stunning roller-coaster display, and this is the best time to see this enigmatic forest bird.