Sunday, April 29, 2007

Asian Paradise Flycatcher

The Asian Paradise Flycatcher, also known as the Common Paradise Flycatcher, is a medium-sized passerine bird. It was before classified with the Old World flycatcher family Muscicapidae, but the paradise flycatchers, monarch flycatchers and Australasian fantails are now usually grouped with the drongos in the family Dicruridae, which has most of its members in Australasia and steamy southern Asia.

The Asian Paradise Flycatcher breeds from Turkistan to Manchuria. It is migratory, wintering in steamy Asia. There are occupant populations further south, for example in southern India and Sri Lanka, so both visiting migrants and the locally breeding subspecies occur in these areas in winter.
This species is usually found in thick forests and other well-wooded habitats. Three or four eggs are laid in a cup nest in a tree.
The adult male Asian Paradise Flycatcher is about 20 cm long, but the long tail bunting double this. It has a black crested head, chestnut upperparts and pale grey underpants.
By their second year, the males of the migratory Indian race T. p. paradise begin to obtain white feathers. By the third year, the male plumage is completely white, other than the black head. Males of the sedentary Sri Lankan race T. p. Ceylonese’s are always chestnut.
The female of all races resembles the old joke male, but has a grey throat, smaller crest and lacks the tail streamers.

Monday, April 23, 2007

Brown Thrasher

The Brown Thrasher is a common type of thrasher, part of a family of New World birds that includes New World catbirds and mockingbirds.The Brown Thrasher is, as the name suggests, mostly brown or reddish-brown on top of, with a white breast and throat streaked with brown, and two white bars on each wing. It has a long tail, and its beak is also relatively large and somewhat curved. Adults average about 29 cm (11.5 in) in length.
It is difficult to see all this however, as the bird is a retiring type that prefers thickets and heavy brush, often searching for food in dry leaves on the ground. In fact, it is more probable to be heard than seen, not only because of the rattling of leaves, but also because of its call, a sharp lip-smacking type sound. This bird is omnivorous, eating insects, berries, nuts and seeds, as well as earthworms, snails and sometimes lizards.Its breeding variety includes the United States and Canada east of the Rocky Mountains. It is a partial migrant, with northern birds wintering in the southern USA, where it occurs all through the year. There is a single British record of this unlikely transatlantic vagrant.The female lays 3 to 5 eggs in a twiggy nest lined with grass. The nest is built in a dense shrub or low in a tree. Both parents incubate and feed the young. These
birds raise two, rarely three, broods in a year. The male sings a series of short recurring melodious phrases from an open perch to defend his territory and is also very aggressive in defending the nest.Although this bird is widespread and still common, it has declined in numbers in some areas due to loss of suitable habitat.The Brown Thrasher is the official state bird of Georgia, and the inspiration for the name of Atlanta's National Hockey League team, the Atlanta Thrashers.

Wednesday, April 18, 2007

Street racing

Street racing is a form of auto racing that takes place on public roads, either through normal traffic or during empty hours of traffic, often inside the industrial areas of cities. It is illegal, as such driving is prohibited by many traffic regulations. Law enforcement officers attempt to stop these races, but because of the frequency of them, most of the time, the racers also are not caught or they get away. Speeds in an illegal street race can reach over 180 miles per hour and crashes can and do occur.

Monday, April 09, 2007

Transistor

The transistor is a solid state semiconductor device which can be used for amplification, switching, voltage stabilization, signal modulation and many other functions. It acts as a variable valve which, based on its input current (BJT) or input voltage (FET), allows a precise amount of current to flow through it from the circuit's voltage supply.
In essence, a transistor have three terminals. A current or voltage applied through/across two terminals controls a larger current through the other terminal and the common terminal. In analog circuits, transistors are used in amplifiers. Analog circuits comprise audio amplifiers, stabilised power supplies and radio frequency amplifiers. In digital circuits, transistors function basically as electrical switches. Digital circuits include logic gates, RAM (random access memory) and microprocessors.
Transistor was also the common name in the sixties for a transistor radio, a portable radio that used transistors (rather than vacuum tubes) as its active electronic components. This is still one of the dictionary definitions of transistor.

Thursday, April 05, 2007

Artistamp

Artistamp refers to a postage stamp-like artform. It is like to a Cinderella stamp, in that it is not valid for postage, but it differs from a forgery or a bogus stamp in that (typically) no intention is made to fool any post office or collector of stamps. The artistamp is intended to be a miniature artform which can depict or commemorate any subject its creator chooses.
Techniques for the creation of artistamps may or may not comprise perforating the boundaries of the piece to more resemble a (water-activated) stamp, as well as applying gum to the reverse side of the paper. (Self-adhesive artistamps have also been made, however, and indeed artistamps have been issued in practically every format in which postage stamps have been—including souvenir sheets, and perhaps more.) Whole sheets of such stamps are often made at one time. The artwork can be hand-drawn or painted, lithographed or offset-printed, photographed, xeroxed, rubber stamped, or even output by computer-driven printer.

Sunday, April 01, 2007

Rail transport

A railroad or railway is a guided means of land transport, intended to be used by trains, for transporting both passengers and freight. It consists of two parallel rails, usually made of steel, and wooden or concrete sleepers or ties that hold the rails precisely at the proper distance from each other. See Rail tracks
Rail transport is one of the most energy well-organized means of mechanised land transport known. The rails give very smooth and hard surfaces on which the wheels of the train may roll with a minimum of friction. This is more comfortable and saves energy. Trains also have a small frontal area in relation to the load they are carrying, which cuts down on air resistance and thus energy usage. In all, under the right circumstances, a train needs 50-70% less energy to transport a given tonnage of freight, than by road. Furthermore, together with the sleepers the rails share out the weight of the train evenly, allowing significantly greater loads per axle/wheel than in road transport.
Rail transport is also one of the safest modes of transport, and also makes a very efficient use of space: a double tracked rail line can carry more passengers or freight in a given amount of time, than a four-laned road.