Tuesday, July 31, 2007

Electrostatic

A thin, electrostatic ally charged diaphragm, is suspended between two perforated metal plates. The electrical sound signal is applied to the electrodes creating an electrical field; depending on the polarity of this field, the membrane is drawn towards one of the plates. Air is forced through the perforations; combined with a continuously changing electrical signal oscillating the membrane, a sound wave is generated.

Sunday, July 22, 2007

Web portal

A Web portal is a site that functions as a point of admittance to information on the World Wide Web. Portals present information from diverse sources in a united way. Popular portals are MSN, Yahoo, and AOL. Aside from the search engine standard, web portals offer other services such as news, stock prices, infotainment and various other features. Portals provide a way for enterprises to provide a steady look and feel with access control and procedures for multiple applications, which otherwise would have been different entities altogether.

Friday, July 13, 2007

Pollarding

Pollarding is a woodland management method of hopeful lateral branches by cutting off a tree stem or minor branches two metres or so above ground level. The tree is given a year to regrow, after the first cutting, but once begun, pollarding requires annual maintenance by pruning. This will ultimately result in somewhat expanded (or swollen) nodes topping the tree trunk with multiple new side and top shoots growing from it.A tree that has been pollarded is known as a pollard. A tree which has not been pollarded is called a maiden or maiden tree; which also refers to the fact that pollarding is usually first undertaken when the tree is quite young. Pollarding older trees typically result in the death of the tree. Pollarding is sometimes abused in attempts to curb the growth of older or taller trees. However, when performed properly it is useful in the practice of arboriculture for tree management.

Sunday, July 08, 2007

Deadheading

Deadheading is the act of removing spent flowers or flowerheads for aesthetics, to prolong bloom for up to several weeks or endorse rebloom, or to put off seeding.Deadheading is beneficial to most herbaceous ornamental plants. It can get better overall look of a plant, give a fresh new look to an otherwise finished or even distracting item, and can promote vegetative and root increase rather than seed production and help retain the plant's healthy appearance.

Sunday, July 01, 2007

Bean

Bean is a common name for large plant seeds of several genera of Fabaceae used for food or feed. They are also known as legumes.The term Bean at first referred to the seed of the broad bean, but was later broadened to include members of the genus Phaseolus such as the common bean or haricot and the runner bean and the related genus Vigna. The term is now applied in a general way to many other related plants such as soybeans, peas, lentils, kidney beans, vetches and lupins.Bean can be used as a near synonym of pulse, an edible legume, though the term "pulses" is usually reserved for leguminous crops harvested for their dry grain. Pulses frequently exclude crops mainly used for oil extraction (like soybean and peanut) or those used exclusively for sowing purposes (clover and alfalfa). Leguminous crops harvested green for food, such as snap beans, green peas etc, are classified as vegetable crops.In English usage 'beans' sometimes also refer to seeds or other organs of non leguminosae which bear a resemblance to the vegetable, for example coffee beans, castor beans and cocoa beans ,and vanilla beans .