Thursday, March 27, 2008
Inkjet Printer
Inkjet printers are a type of computer printer that operates by propelling minute droplets of liquid ink onto paper. They are the most general type of computer printer for the general consumer due to their low cost, high quality of output, capability of printing in vivid color, and ease of use
In the personal and small business computer market, inkjet printers presently predominate. Inkjets are usually cheap, quiet, reasonably fast, and many models can produce high quality output. Like most modern technologies, the present-day inkjet has built on the progress made by many earlier versions. Among many contributors, Epson, Hewlett-Packard and Canon can claim a substantial share of credit for the growth of the modern inkjet. In the worldwide consumer market, four manufacturers account for the majority of inkjet printer sales: Canon, Hewlett-Packard, Epson, and Lexmark.
Monday, March 10, 2008
Lithography
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, March 03, 2008
Metal
In chemistry, a metal is an constituent that readily loses electrons to form positive ions and has metallic bonds between metal atoms. Metals form ionic bonds with non-metals. They are sometimes described as a web of positive ions surrounded by a cloud of delocalized electrons. The metals are one of the three groups of elements as eminent by their ionization and bonding properties, along with the metalloids and nonmetals. On the periodic table, a diagonal line drawn from boron separates the metals from the nonmetals. Most elements on this line are metalloids, sometimes called semi-metals; elements to the lower left are metals; elements to the upper right are nonmetals.
A modern definition of metals is that they have overlapping conveyance bands and valence bands in their electronic structure. This definition opens up the category for metallic polymers and other organic metals, which have been prepared by researchers and employed in high-tech devices. These synthetic materials often have the characteristic silvery-grey reflectiveness of elemental metals.
