Sunday, April 29, 2007

Biotechnology

Biological technology is technology based on biology, particularly when used in agriculture, food science, and medicine. Biotechnology means any technological application that uses biological systems, living organisms, or derivatives thereof, to construct or change products or processes for specific use.

Biotechnology combines disciplines like genetics, molecular biology, biochemistry, embryology and cell biology, which are in turn allied to practical disciplines like chemical engineering, information technology, and robotics.Biotechnology can also be defined as the exploitation of organisms to do practical things and to provide useful products.

One characteristic of biotechnology is the directed use of organisms for the manufacture of organic products (examples include beer and milk products). For another example, naturally present bacteria are utilized by the mining industry in bioleaching. Biotechnology is also used to recycle, treat waste, clean up sites infected by industrial activities (bioremediation), and produce biological weapons.

Monday, April 23, 2007

Solid us

100 A solid us was originally a gold coin issued by the Romans.
Julian solid us, ca. 361.It were introduced by Constantine I in the AD 309–10, and was used through the Byzantine Empire until the 10th century AD. The coin replaced the aurous as the main gold coin of the Roman Empire.

The name solid us had previously been used by Diocletian for the gold coin that he introduced, which is different from the solid us introduced by Constantine. The coin was struck at a theoretical value of 1/72 of a Roman pound. Solid were wider and thinner than the aurous, with the exception of some dumpy issues from the Byzantine Empire. The weight and fineness of the solid we remained relatively constant throughout its long production, with few exceptions. Fractions of the solid us known as surmises and tiramisus were also produced.


Aviates dermises, ca. 456.The word soldier is ultimately derived from solid us, referring to the solid with which soldiers were paid.

Thursday, April 19, 2007

"Wireless" factories and vacuum tubes

Marconi opened the world's first "wireless" factory in Hall Street, Chelmsford, England in 1898, employing around 50 people. Around 1900, Tesla opened the Wardenclyffe Tower facility and advertised services. By 1903, the tower structure neared completion. Various theories exist on how Tesla planned to achieve the goals of this wireless system. Tesla claimed that Wardenclyffe, as part of a World System of transmitters, would have permitted secure multichannel transceiving of information, universal navigation, time synchronization, and a global location system.The next great invention was the vacuum tube detector, invented by a team of Westinghouse engineers. On Christmas Eve, 1906, Reginald Fessenden ransmitted the first radio audio broadcast in history from Brant Rock, Massachusetts. Ships at sea heard a broadcast that included Fessenden playing O Holy Night on the violin and reading a passage from the Bible. The world's first radio news program was broadcast August 31, 1920 by station 8MK in Detroit, Michigan. The world's first regular wireless broadcasts for entertainment commenced in 1922 from the Marconi Research Centre at Writtle near Chelmsford, England.

Tuesday, April 10, 2007

History of the chair

The chair is of great antiquity, although for many centuries and indeed for thousands of years it was an article of state and self-respect rather than an article of normal use. “The chair” is still widely used as the emblem of authority in the House of Commons and in public meetings. It was not, in fact, until the 16th century that it became common anywhere. The chest, the bench and the stool were until then the ordinary seats of everyday life, and the number of chairs which have survived from an earlier date is exceedingly limited; most of such examples are of clerical or seigniorial origin. Our knowledge of the chairs of remote antiquity is derived almost entirely from monuments, sculpture and paintings. A few actual examples exist in the British Museum, in the Egyptian museum at Cairo, and elsewhere.

Egyptian chairs

In ancient Egypt chairs appear to have been of great richness and splendor. Fashioned of ebony and- ivory, or of stamped and gilded wood, they were covered with costly materials and supported upon representations of the legs of beasts or the figures of captives. An arm-chair in fine protection found in a tomb in the Valley of the Kings is astonishingly similar, even in small details, to that "Empire" style which followed Napoleon’s campaign in Egypt. The initial monuments of Nineveh represent a chair without a back but with tastefully carved legs ending in lions’ claws or bulls’ hoofs. Others are supported by figures in the nature of caryatides or by animals.

Greek and Roman chairs
The initial known form of Greek chair, going back to five or six centuries before Christ, had a back but stood straight up, front and back. On the fresco of the Parthenon Zeus occupies a square seat with a bar-back and thick turned legs; it is bejeweled with winged sphinxes and the feet of beasts. The characteristic Roman chairs were of marble, also adorned with sphinxes. The curule chair was initially very similar in form to the modern folding chair, but finally received a good deal of ornament. The most renowned of the very few chairs which have come down from a remote antiquity is the reputed chair of St. Peter in St Peter's Basilica at Rome. The wooden portions are much moldy, but it would appear to be Byzantine work of the 6th century, and to be really an ancient sedia gestatoria.

Friday, April 06, 2007

Goshawk

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

It is an extensive species all through the moderate parts of the northern hemisphere. In North America it is named as the Northern Goshawk. It is typically inhabitant, but birds from colder regions of north Asia and Canada journey south for the winter.


Goshawk in flight this species nests in trees, building a new nest each year. It hunts birds and mammals in woodland, relying on revelation as it flies from a perch or hedge-hops to catch its quarry ignorant. Animals as large as hares and Pheasant are taken. Its call is a ferocious screech. Many older goshawks reject to attack hares, if it was earlier seriously kicked by a hare which it tried to catch.

This bird is a raptor with short large wings and a long tail, both adaptations to maneuvering through trees. The male is blue-grey above and banned grey below, 49-56 cm long with a 93-105 cm wingspan. The much larger female is 58-64 cm long with a 108-127 cm wingspan, slate grey above grey below. The youthful is brown above and barred brown below. The flight is a characteristic "slow flap – slow flap – straight glide".

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

Monday, April 02, 2007

Airliner

Definition and description

An airliner is a great fixed-wing aircraft whose key function is for the carry of paying passenger. Airliners are typically operated by an airline company which owns or leases the aircraft.


An Airbus A340 airliner operated by Air Jamaica. The description of an airliner can differ from country to country, but typically, 20 or more traveler seats or an unfilled weight above 50,000 lb qualifies an aircraft as an airliner.

Passenger aircraft with fewer than 20 passenger places are called commuter aircraft or air taxis, depending on their size, engines and seating configurations.

While piston engines were common on prop liners like the Douglas DC-3 until the opening of the jet age, nearly all modern airliners are powered by turbine engines, either turbofans or turboprops, since they work resourcefully at much higher altitudes, are far more dependable than piston engines, and provide a ride with less shaking and noise for the passengers.

There may be variants of an airliner that are residential for moving freight or for luxury corporate use. Many airliners have also been adapted for government use as "VIP" transports and for various unarmed functions such as airborne, air ambulance, reconnaissance as well as the more obvious troop-carrying roles.