Renewable Energy

Geothermal Energy
The word geothermal comes from the Greek words geo meaning (earth) and therme meaning (heat). With breaking down the word Geothermal we can understand that geothermal energy is heat from within the earth. We can use the steam and hot water produced inside the earth to heat buildings or generate electricity. Geothermal energy is a renewable energy source because the water is replenished by rainfall and the heat is continuously produced inside the earth.
For more info:
http://www.eia.doe.gov/kids/energyfacts/sources/renewable/geothermal.html
Video Link:
http://www.howstuffworks.com/geothermal-energy.htm


Solar Power
Solar panels are devices that collect the energy from the sun light or rays, and convert it into useful energy. These types of devices are the best for the environment because the methods of consuming energy has no reprecussions. There are two types of solar panels, a photovoltaic module and a solar thermal collector.
A photovoltaic module is a device that consist of an assembly of connected solar cells that collect the sun's rays and convert it into clean, consumable energy. The actual material that the solar cells consist of are waffer-based monocrystaline silicon. The way it works is that the energy that is collected is stored into a battery for later use, dispelling the stereotype of "lights out" when it comes to night time.
A solar thermal collector is somewhat similar to a photovoltaic module, except the cells in consist of sole purpose is to collect the sun's light in order to produce heat to heat water and create energy. The way this device work is that the sun's light is collected and becomes heat, therefore heating water to steam for a turbine connected to a electric generator.

For more info:
http://www.solarpanelinfo.com/
Video Link:
http://www.howstuffworks.com/search.php?terms=solar+power&gallery=1&media=video

Computer Viruses

A computer virus is a computer program that can copy itself and infect a computer without the permission or knowledge of the owner. The term "virus" is also commonly but erroneously used to refer to other types of malware, adware, and spyware programs that do not have the reproductive ability. A true virus can only spread from one computer to another (in some form of executable code) when its host is taken to the target computer; for instance because a user sent it over a network or the Internet, or carried it on a removable medium such as a floppy disk, CD, DVD, or USB drive. Viruses can increase their chances of spreading to other computers by infecting files on a network file system or a file system that is accessed by another computer.
The term "computer virus" is sometimes used as a catch-all phrase to include all types of malware. Malware includes computer viruses, worms, trojan horses, most rootkits, spyware, dishonest adware, crimeware, and other malicious and unwanted software), including true viruses. Viruses are sometimes confused with computer worms and Trojan horses, which are technically different. A worm can exploit security vulnerabilities to spread itself to other computers without needing to be transferred as part of a host, and a Trojan horse is a program that appears harmless but has a hidden agenda. Worms and Trojans, like viruses, may cause harm to either a computer system's hosted data, functional performance, or networking throughput, when they are executed. Some viruses and other malware have symptoms noticeable to the computer user, but many are surreptitious.

For more info:
http://www.howstuffworks.com/virus.htm
Video Link:
http://www.howstuffworks.com/virus.htm





Mp3 player Technology
Unlike earlier forms of music players that required moving parts to read encoded data on a tape or CD, MP3 players use solid-state memory. An MP3 player is no more than a data-storage device with an embedded software application that allows users to transfer MP3 files to the player. MP3 players also include utilities for copying music from the radio, CDs, radio or Web sites and the ability to organize and create custom lists of songs in the order you want to hear them. This list of songs is called a playlist.The MP3 player is the convergence of many technologies. Alone, none of its components are revolutionary, but together they create an unprecedented consumer product.
In the inside of a Rio MP3 player. You can see the LCD panel, several large chips (the microprocessor, DSP chip and I/O controller), the amplifier and the buttons.
The player plugs into your computer's USB port, FireWire port or parallel port to transfer data. USB-based players transfer data many times faster than those that use the parallel port. The MP3 files are saved in the player's memory.
Memory types include:
Internal Flash memory
CompactFlash cards
SmartMedia cards
Memory Stick
Internal microdriv
With the exception of the last one, these are all types of solid-state memory. The advantage to solid-state memory is that there are no moving parts, which means better reliability and no skips in the music. MP3 players that contain tiny hard disk drives can store 10 to 150 times more than Flash memory devices can.The microprocessor is the brains of the player. It monitors user input through the playback controls, displays information about the current song on the LCD panel and sends directions to the DSP chip that tells it exactly how to process the audio.
In addition to storing music, the MP3 player must play music and allow the user to hear the songs played.

To do this, the player:
Pulls the song from its memory.
Decompresses the MP3 encoding, through DPS, via an algorithm or formula.
Runs the decompressed bytes through a digital-to-analog converter into sound waves.
Amplifies the analog signal, allowing the song to be heard.
All of the portable MP3 players are battery-powered. Most use a rechargeable internal lithium battery and last for approximately 10 to 28 hours on a single charge. Many of the players also have AC adapters so they can be plugged into a normal electrical outlet, and some even offer DC adapters for use in a car.

For more info:
http://en.wikipedia.org/wiki/MP3
Video Link:
http://electronics.howstuffworks.com/mp3-player.htm