Monday, April 28, 2008

Education System

Schooling occurs when group or a society or an individual sets up a curriculum to educate people, usually the young. Schooling can become systematic. Sometimes education systems can be used to promote doctrine or ethics as well as knowledge, and this can lead to abuse of the system.

Life-long or adult educations have become extensive in many countries. However, education is still seen by many as something aimed at children, and adult education is often branded as adult learning or ultimate learning.

Adult education takes on several forms, from formal class-based learning to self-directed learning. Lending libraries provide cheap informal access to books and other self-instructional materials. Many adults have also taken advantage of the rise in computer ownership and internet access to further their casual education.

Tuesday, April 22, 2008

Dot matrix printer

Unlike a typewriter or daisy wheel printer, letters are tired out of a dot matrix, and thus, varied fonts and random graphics can be produced. Because the printing involves mechanical pressure, these printers can create carbon copies and carbonless copies. A dot matrix printer or impact matrix printer refers to a type of computer printer with a print head that runs back and forth on the page and prints by impact, outstanding an ink-soaked cloth ribbon beside the paper, much like a typewriter.

Each dot is formed by a tiny metal rod, also called a "wire" or "pin", which uses the power of a tiny electromagnet or solenoid to drive it forward, either directly or through small levers .Facing the ribbon and the paper is a small guide plate (often made of an artificial jewel such as sapphire or garnet) pierced with hole to provide as guides for the pins. The moving portion of the printer is called the print head, and prints one line of text at a time.The majority dot matrix printers have a single vertical line of dot-making apparatus on their print heads; others have a few interleaved rows in order to improve dot density.

These machines can be highly durable, but eventually wear out. Ink invades the direct plate of the print head, causing grit to adhere to it; this grit slowly causes the channels in the guide plate to wear from circles into ovals or slots, providing less and less correct guidance to the printing wires. After about a million characters, even with tungsten blocks and titanium pawls, the printing becomes too unclear to read.

Deadheading

Deadheading is the act of removing spent flowers or flowerheads for aesthetics, to extend bloom for up to several weeks or endorse rebloom, or to put off seeding.Deadheading is valuable to most herbaceous ornamental plants. It can get improved 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.

Wednesday, April 16, 2008

Chain

A broad metal chain made of torus-shaped links. A metal chain with diamond fashioned link pins. Roller chains, a chain is a sequence of connected links, usually made of metal.
Chains are typically made in one of two styles, according to their intended use: Those designed for lifting, such as when used with a hoist, or for securing, such as with a bicycle lock, have links that are torus shaped, which makes the chain flexible in two dimensions. Those designed for transferring power in machines have links designed to mesh with the teeth of the gears of the machine, and are flexible in only one dimension. They are known as Roller chains. Chains can also be ornamental as jeweler.

Thursday, April 03, 2008

Bluetooth

Bluetooth is an industrial requirement for wireless personal area networks (PANs). Bluetooth provides a way to connect and swap information between devices such as mobile phones, laptops, PCs, printers, digital cameras, and video game consoles over a secure, globally unlicensed short-range radio frequency. The Bluetooth specifications are licensed and developed by the Bluetooth Special Interest Group.

Bluetooth is a radio standard and communications protocol mostly designed for low power consumption, with a short range based on low-cost transceiver microchips in each device. The devices use a radio communications system, so they do not have to be in line of view of each other, and can even be in other rooms, as long as the conservative transmission is powerful enough.