Saturday, September 29, 2007


Animals are a main set of organisms, classified as the empire Metazoa. In general they are multi­cellular, receptive to their surroundings, and provide for by consuming other organisms or parts of them. Their body plan becomes fixed when they develop, generally early on in their growth as embryos, though some feel a process of metamorphosis later on.

The word "animal" comes from the Latin word animal, of which Metazoa is the plural, and is resulting from anima, sense vital breath or soul. In each day colloquial usage, the word regularly refers to non-human animals. The biological meaning of the word refers to all members of the empire Animalia. Therefore, as the word "animal" is used in a biological circumstance, humans are included.

Monday, September 24, 2007


Lithography is a technique for printing on a smooth surface. It can be used to print text or artwork onto paper or another appropriate material. It can also refer to photolithography, a microfabrication method used to construct integrated circuits and microelectromechanical systems. Lithography works because of the revulsion of oil and water.Lithography was invented by Alois Senefelder in 1798.

Lithography is a printing method that uses chemical processes to make an image. For instance, the positive part of an image would be a hydrophobic chemical, while the negative image would be water. Thus, when the plate is introduced to a companionable ink and water mixture, the ink will adhere to the positive image and the water will clean the negative image. This allows for a comparatively flat print plate which allows for much longer runs than the older physical methods of imaging (e.g., embossing or engraving). current high-volume lithography is used to make posters, books, newspapers, packaging, credit cards, decorated CDs – just about any smooth, mass-produced item with print on it.

Monday, September 17, 2007

Propeller aircraft

Smaller and older propeller aircraft make use of reciprocating internal combustion engines that turns a propeller to create force. They are quieter than jet aircraft, but they fly at lower speeds, and have lower load capacity compared to similar sized jet powered aircraft. However, they are considerably cheaper and much more cost-effective than jets, and are usually the best option for people who need to transport a few passengers and/or small amounts of cargo. They are also the aircraft of choice for pilots who wish to own an aircraft.Turboprop aircraft are a intermediate point between propeller and jet: they use a turbine engine similar to a jet to turn propellers. These aircraft are popular with traveler and regional airlines, as they tend to be more economical on shorter journeys.