Friday, April 27, 2007

Microprocessor

A microprocessor is a programmable component. It incorporates the functions of a central processing unit (CPU) on a single semi conducting integrated circuit (IC). The microprocessor was born by dipping the word size of the CPU from 32 bits to 4 bits, so that the transistors of its logic circuits would vigorous onto a single part. One or more microprocessors typically serve up as the CPU in a computer system, embedded system, or handheld device.

Microprocessors made probable the beginning of the microcomputer in the mid-1970s. Before this period, electronic CPUs were typically made from massive distinct switching devices (and later small-scale integrated circuits) containing the equivalent of only a few transistors. By integrating the processor onto one or a very few large-scale integrated circuit packages (containing the equivalent of thousands or millions of discrete transistors), the cost of processor power was greatly reduced. Since the dawn of the IC in the mid-1970s, the microprocessor has become the most rampant implementation of the CPU, nearly completely replacing all other forms. See History of computing hardware for pre-electronic and early electronic computers.

Tuesday, April 24, 2007

Purely Way

Purely Way is a section of the A23 trunk road in Corydon, London and has given its name to the out-of-town shopping area alongside it with a catchments area covering most of South London. It was designed as a bypass for Corydon and was opened in April 1925. In 1932 Purely Way became the first road in the United Kingdom to be lit with sodium lights.

Industry History

The IKEA chimneysCroydon Airport is located on Purely Way.

The opening of Purely Way attracted industry to the area and it became the main industrial area of Corydon. Industry attracted to the area included Redwing Aircraft Ltd, Trojan Ltd (car manufacturers) and Tizer Ltd. There were also several metal companies including Standard Steel Co, Corydon Foundry Ltd, Metal Propellers Ltd and Southern Foundries Ltd.

Corydon 'B' Power Station was built in the late 1940s and opened in 1950. It shut down in 1984, was demolished in 1991 and an IKEA store was opened on the site. The large chimneys of the power station were retained and remain a local pointer.

Wednesday, April 18, 2007

Videophone

A videophone is a telephone which is able of both audio and video duplex transmission.AT&T conducted experiments and demonstrations of a "Picturephone" product and service in the early 1960s. Among the first manufacturers of commercially viable videophones was Toshiba.Videotelephony is frequently used in large corporate setups, and are supported by systems such as Cisco CallManager. Other companies such as Tandberg, Radvision, and Polycom also offer similar solutions. Videoconferencing has usually been limited to the h.323 protocol (notably Cisco's SCCP implementation is an exception), however newly a shift towards SIP implementations is seen. In accordance with the adoption of SIP telephony for home users, videotelephony is also slowly becoming available to home users.Another protocol using videophones is H.324; this allows videophones to work in regular phone lines, since the bandwidth is limited by the phone line. The quality is about fifteen Frames per second. This type of videophone is generally used because of the affordable price.Today the principles, if not the precise mechanisms of a videophone are employed by thousands of users world-wide in the form of webcam conferences using cheaply available webcams and microphones employed using software over the internet.

Monday, April 09, 2007

Willamette River

100 The Willamette River is a tributary of the Columbia River, approximately 240 mi long, in northwestern Oregon in the United States. Flowing northward between the Coastal Range and Cascade Range, the river and its tributaries form a basin called the Willamette Valley containing the largest inhabitants centers of Oregon, including Portland, which sits along both sides of the river near its mouth on the Columbia. Its lush valley is fed by prolific precipitation on the western side of the Cascades, forming one of the most productive agricultural regions of North America that was the destination for many if not most of the emigrants along the Oregon Trail. The river was an important transportation route throughout much of the early history of the state, furnishing a means of conveying the vast timber and agricultural resources of the state to the outside world.

Description

The Willamette rises in three separate forks in the mountains south and southeast of Eugene, at the southern end of the Willamette Valley. The Middle Fork and North Fork raise on the western side of the Cascades between Three Sisters south to Diamond Peak, with the Middle Fork in receipt of the North Fork northwest of Oakridge and flowing northwest from side to side the mountains to the southern end of the Willamette Valley. The Coast Fork rises in the lower mountains south of Cottage Grove, flowing north to join the Middle Fork 2 mi southeast of Eugene.

From Eugene, the joint river flows NNW across the plain of the southern Willamette Valley to Corvallis, and then follows a zigzag course past Albany and around the isolated hills in the central valley, passing west of downtown Salem. From Salem it flows north in a roundabout course across the northwest plain of the valley, reaching the hills at Newberg, where it turns sharply ENE along the hills, passing through an opening in the hills at Oregon City, the position of the Falls of the Willamette and the head of navigation. From Oregon City it flows northwest, past Lake Oswego and Milwaukie on the south edge of Portland, then passing between east and west Portland, where it is spanned by a series of urban bridges. Downstream of downtown Portland it flows northwest through the industrial port area of Portland Harbor, then splitting into two channels around Sauvie Island, both of which hook around to enter the Columbia from the west, with the main channel entering on the north edge of Portland and the smaller Multnomah Channel entering just about 15 mi NNW at St.Helens.

Monday, April 02, 2007

Ultraviolet

Ultraviolet radiation is electromagnetic radiation of a wavelength shorter than that of the able to be seen region, but longer than that of soft X-rays. It can be subdivided into near UV and tremendous or vacuum UV.

When allowing for the effects of UV radiation on human health and the surroundings, the range of UV wavelengths is often subdivided into UVA, also called Long Wave or "black light"; UVB, also called Medium Wave; and UVC, also called Short Wave or "germicidal". See 1 E-7 m for a list of objects of similar sizes.

In photolithography, in laser technology, etc., the term cavernous ultraviolet or DUV refers to wavelengths below 300nm.

The name means "beyond violet", violet being the color of the unswerving wavelengths of able to be seen light. Some of the UV wavelengths are colloquially called black light, as it is imperceptible to the human eye. Some animals, including birds, reptiles, and insects such as bees, can see into the near ultraviolet. Many fruits, flowers, and seeds situate out more strongly from the background in ultraviolet wavelengths as compared to human color vision. Many birds have patterns in their plumage that are imperceptible at usual wavelengths but seen in ultraviolet, and the urine of some animals is much easier to spot with ultraviolet.

The Sun emits ultraviolet radiation in the UVA, UVB, and UVC bands, but because of amalgamation in the atmosphere's ozone layer, 99% of the ultraviolet radiation that reaches the Earth's surface is UVA.
Ordinary glass is see-through to UVA but is opaque to shorter wavelengths. Silica or quartz glass, depending on quality, can be see-through even to vacuum UV wavelengths.

The onset of vacuum UV, 200 nm, is defined by the fact that normal air is opaque below this wavelength. This opacity is due to the strong amalgamation of light of these wavelengths by oxygen in the air. Pure nitrogen is see-through to wavelengths in the range of about 150–200 nm. This has wide practical significance now that semiconductor manufacturing processes are using wavelengths shorter than 200 nm. By working in oxygen-free gas, the apparatus does not have to be built to withstand the pressure differences necessary to work in a vacuum. Some other scientific instruments, such as circular dichroism spectrometers, are also normally nitrogen purged and operate in this spectral region.