Tuesday, March 27, 2007

Mainframe computer

Mainframes are large and "expensive" computers used mainly by government institutions and large companies for mission critical applications, characteristically bulk data processing such as censuses, industry/consumer statistics, ERP, and financial transaction processing.
The term originated through the early 1970s with the introduction of smaller, less complex computers such as the DEC PDP-8 and PDP-11 series, which became known as minicomputers or just minis. The industry/users then coined the term "mainframe" to describe larger, earlier types (previously known simply as "computers").
Modern mainframe computers contain abilities not so much defined by their performance capabilities as by their high-quality internal engineering and resulting proven reliability, expensive but high-quality technical support, top-notch security, and strict backward compatibility for older software. These machines can and do run successfully for years with no interruption, with repairs taking place whilst they continue to run. Mainframe vendors offer such services as off-site redundancy — if a machine does break down, the vendor offers the option to run customers' applications on their own machines (often without users even noticing the change) whilst repairs go on.

Thursday, March 22, 2007


A polymer is a general term used to explain a substantially long molecule. This long molecule consists of structural units and repeating units strung together throughout chemical bonds. The process of converting these units to a polymer is called polymerization. These units are called monomers, which are characteristically small molecules of low molecular weight.
The monomers can be identical, or they can have one or more substituted chemical groups. These differences between monomers can have an effect on properties such as solubility, flexibility, or strength. In proteins, these differences can give the polymer the ability to preferentially adopt one conformation over another, as opposed to adopting a random coil (see self-assembly). Although most polymers are organic (based on carbon chains), there are also inorganic polymers, mainly based on a silicon backbone.
The term polymer covers a large, diverse group of molecules, including substances from proteins to high-strength kevlar fibres. A key feature that distinguishes polymers from other large molecules is the repetition of units of atoms (monomers) in their chains. This occurs during polymerization, in which many monomer molecules link to each other.

Friday, March 16, 2007


The Palace Pier (renamed Brighton Pier in 2000) opened in May 1899 and is still popular. It suffered a large fire on 4 February 2003 but the injure was limited and most of the pier was able to reopen the next day.
The even older West Pier, built in 1866, has been closed since 1975 awaiting renovation. The West Pier is one of only two Grade I listed piers in the UK, the other being Clevedon Pier. Plans to renovate the pier have been different by some local residents who claim that the future new onshore structures - which the renovators need to pay for the work on the pier - would obstruct their view of the sea. The restoration is also opposed by the owners of the Brighton Pier, who supposedly see its subsidised rebuilding, were it to happen, as unfair competition.
The West Pier incompletely collapsed on December 29, 2002 when a walkway connecting the concert hall and pavilion fell into the sea after being battered by storms. On January 20, 2003 a further collapse saw the destruction of the concert hall in the middle of the pier. On March 28, 2003 the pavilion at the end of the pier caught fire. Firefighters were unable to save the building from destruction because of the precarious state of the walkway. The cause of the fire remains unknown. On May 12, 2003, another fire broke out, intense most of what was left of the concert hall. Arson was supposed. On June 23, 2004 high winds caused the middle of the pier to completely collapse.
Despite all these setbacks, the owner of the site West Pier Trust remained obstinate they would soon begin full restoration work. Finally, in December 2004, the trust admitted defeat, after their plans were discarded by English Heritage and the Lottery Heritage Fund. They still hope to reconstruct the pier in some form, though restoration is no longer their goal.

Monday, March 12, 2007

Ice travel

Ice can also be an obstacle; for harbors near the poles, being ice-free is an significant advantage, ideally all-year round. Examples are Murmansk (Russia), Petsamo (Russia, formerly Finland) and Vardø (Norway). Harbors that are not ice-free are opened up using icebreakers.
Ice forming on roads is a unsafe winter hazard. Black ice is very difficult to see because it lacks the predictable glossy surface. Whenever there is freezing rain or snow that occurs at a temperature near the melting point, it is common for ice to build up on the windows of vehicles. Driving safely requires the removal of the ice build-up. Ice scrapers are tools designed to break the ice free and clear the windows, while removing the ice can be a long and labor-intensive process.
Far enough below the freezing point, a thin layer of ice crystals can form on the inside surface of windows. This frequently happens when a vehicle has been left alone after being driven for a while, but can happen while driving if the outside temperature is low enough. Moisture from the driver's breath is the source of water for the crystals. It is troublesome to take away this form of ice, so people often open their windows somewhat when the vehicle is parked in order to let the moisture dissipate, and it is now common for cars to have rear-window defrosters to combat the problem. A similar problem can happen in homes, which is one reason why many colder regions require double-pane windows for insulation.
When the outdoor temperature stays below freezing for comprehensive periods, very thick layers of ice can form on lakes and other bodies of water (although places with flowing water require much colder temperatures). The ice can become thick enough to drive onto with automobiles and trucks. Doing this safely requires a thickness of at least 30 centimeters (one foot).

Wednesday, March 07, 2007


A piano or pianoforte is a musical instrument classified as a keyboard, percussion, or string instrument, depending on the system of categorization used. The piano produces sound by striking steel strings with felt hammers that at once rebound allowing the string to continue vibrating at its resonant frequency. These vibrations are transmitted through the bridges to the soundboard, which amplifies them.
The piano is generally used in western music for solo performance, chamber music, and accompaniment. It is also very popular as an aid to composing and rehearsal. Even though not portable and often expensive, the piano's versatility and ubiquity has made it among the most familiar of musical instruments.
The word piano is a shortened form of the word pianoforte, which is seldom used except in formal language and resultant from the original Italian name for the instrument, gravicèmbalo col piano e forte (literally harpsichord with soft and loud). This refers to the capability of the piano to produce notes at different volumes depending on the amount of force used to press the keys.

Friday, March 02, 2007

Morello Cherry

The Sour Cherry or Morello Cherry, (Prunus cerasus) is a class of Prunus in the subgenus Cerasus (cherries), native to much of Europe and southwest Asia. It is closely related to the Wild Cherry (P. avium), also known as sweet cherry, but has a fruit which is more acidic, and so is useful mainly for culinary purposes.
The tree is smaller than the Wild Cherry, increasing up to 4-10 m tall, and has twiggy branches, whilst the crimson to black fruit is borne on shorter stalks.
Sour Cherries require comparable cultivation conditions to pears, that is, they prefer a rich, well-drained moist soil, although they demand more nitrogen and water than sweet cherries. Trees will do badly if waterlogged, but have larger tolerance of poor drainage than sweet varieties. As with sweet cherries, Morellos are usually cultivated by budding onto strong growing rootstocks, which produce trees too large for most gardens, although newer dwarfing rootstocks such as Colt and Gisella are now available. During spring, flowers should be sheltered, and trees weeded, mulched and sprayed with seaweed solution. This is also the time when any required pruning should be carried out (note that cherries should not be pruned during the dormant winter months). Morello cherry trees fruit on younger wood than sweet varieties, and thus can be pruned harder. They are usually grown as standards, but can be fan trained, cropping well even on cold walls, or grown as low bushes.