Tuesday, July 31, 2007

Headphones

Headphones are a pair of small loudspeakers, or less commonly a single speaker, with a way of holding them close to a user's ears and a means of linking them to a stereophonic or monophonic audio-frequency signal source such as an audio amplifier, radio, etc. In the context of telecommunication, the term headset is used to describe a combination of
Headphone and microphone used for two-way communication, for example with a telephone.

Sunday, July 22, 2007

Metal

In chemistry, a metal is a ingredient 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.

Friday, July 13, 2007

Vegetable

Vegetable is a culinary term which usually refers to an edible part of a plant. The definition is traditional rather than scientific and is somewhat capricious and subjective. All parts of herbaceous plants eaten as food by humans, entire or in part, are normally considered vegetables. Mushrooms, though belonging to the biological realm fungi, are also commonly considered vegetables. In general, vegetables are thought of as being savory, and not sweet, even though there are many exceptions. Nuts, grains, herbs, spices and culinary fruits (see below) are usually not considered vegetables.

Sunday, July 08, 2007

Extranet

An extranet is a personal network that uses Internet protocols, network connectivity, and possibly the public telecommunication system to securely share part of an organization's information or operations with suppliers, vendors, partners, customers or other businesses. An extranet can be viewed as part of a company's Intranet that is extended to users outside the company. It has also been described as a "state of mind" in which the Internet is professed as a way to do business with other companies as well as to sell products to customers.

Sunday, July 01, 2007

Lopping

Lopping, also known as tree lopping and topping, is the practice of cutting trunks and branches of a tree in an effort to contain the tree's size or shape. Lopping is differentiated from other styles of pruning by where the cuts are made. When a tree is lopped, the cuts are made internodally, or not at branch unions and collars at the correct angles, leaving a piece of protruding timber that is called a stub.
Lopping in many cases is careful an inappropriate pruning method for amenity trees. The lopped stubs may regrow adventitious epicormic shoots which are bonded only to the bark. These epicormic shoots can grow dynamically and, unless regularly pruned off, may outgrow the original height and spread of the tree. Further, the ends of the lopped stubs are exposed to pathogens which may enter and infect the tree.
In orchards, fruit trees are often lopped to encourage regrowth and to keep a smaller tree for ease of picking fruit. The pruning regime in orchards is more intended and the productivity of each tree is an important factor. In an orchard, though, the natural longevity of a tree is often compromised in favor of its output in fruiting. Orchard trees are also carefully monitored and treated with fungicides and insecticides to minimise losses.