Thursday, April 24, 2008

Acoustic Neuroma

Also called: Acoustic neurilemoma, Acoustic neurinoma, Vestibular schwannoma

Acoustic neuroma is a non-cancerous tumor that develops on the nerve that connects the ear to the brain. The tumor usually grows slowly. As it grows, it presses against the hearing and balance nerves. At first, you may have no symptoms or mild symptoms. They can include

* Loss of hearing on one side
* Ringing in ears
* Dizziness and balance problems

Acoustic neuroma can be difficult to diagnose, because the symptoms are similar to those of middle ear problems. Ear exams, hearing tests and scans can show if you have it.

If the tumor stays small, you may only need to have it checked regularly. If you do need treatment, surgery and radiation are options. If the tumors affect both hearing nerves, it is often because of a genetic disorder called neurofibromatosis. The tumor can also eventually cause numbness or paralysis of the face. If it grows large enough, it can press against the brain, becoming life-threatening.

Wednesday, April 09, 2008

power

Mobile phones are generally obtaining power from batteries which can be recharged from mains power source. previously, the most common form of mobile phone batteries were nickel metal-hydride, as they have a low size and weight. Sometimes lithium-Ion batteries are used, as they are lighter and do not have the voltage depression that nickel metal-hydride batteries do. Many mobile phone manufacturers have now changed to using lithium-Polymer batteries as to oppose the older Lithium-Ion, the main advantages of this being even lower weight and the possibility to make the battery a shape other than strict cuboid. Mobile phone manufacturers have been experimenting with alternate power sources, including solar cells etc….

In addition to the battery, most cellphones require a small microchip, called a SIM Card, to operate.. Approximately the size of a one-cent postage stamp, the SIM Card is installed underneath the battery in the rear of the unit, and stores the phone's configuration data, and information about the phone itself, such as which calling plan the subscriber is using. When the subscriber removes the SIM Card, it can be re-inserted into another phone and used as normal this can be done easily..

Each SIM Card is activated by a unique numerical identifier ; once activated, that identifier is locked down and the card is permanently locked in to the activating network. Sim cards plays a major role in the mobile phones….