Friday, September 9, 2011

Monday, March 21, 2011

How Nuclear Power Works

Japan Earthquake and Tsunami Image Gallery


Photo by DigitalGlobe via Getty Images
Satellite view of the Fukushima-Daichii nuclear power plant on March 16, 2011, after an 8.9 magnitude earthquake and tsunami set in motion a chain of disastrous events at the facility. See more pictures of the aftermath of Japan's earthquake and Tsunami.
The nuclear power plant stands on the border between humanity's greatest hopes and its deepest fears for the future.

On one hand, atomic energy offers a clean energy alternative that frees us from the shackles of fossil fuel dependence. On the other, it summons images of disaster: quake-ruptured Japanese power plants belching radioactive steam, the dead zone surrounding Chernobyl's concrete sarcophagus.

But what happens inside a nuclear power plant to bring such marvel and misery into being? Imagine following a volt of electricity back through the wall socket, all the way through miles of power lines to the nuclear reactor that generated it. You'd encounter the generator that produces the spark and the turbine that turns it. Next, you'd find the jet of steam that turns the turbine and finally the radioactive uranium bundle that heats water into steam. Welcome to the nuclear reactor core.

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The water in the reactor also serves as a coolant for the radioactive material, preventing it from overheating and melting down. In March 2011, viewers around the world became well acquainted with this reality as Japanese citizens fled by the tens of thousands from the area surrounding the Fukushima-Daiichi nuclear facility after the most powerful earthquake on record and the ensuing tsunami inflicted serious damage on the plant and several of its reactor units. Among other events, water drained from the reactor core, which in turn made it impossible to control core temperatures. This resulted in overheating and a partial nuclear meltdown [source: NPR].

As of March 1, 2011, there were 443 operating nuclear power reactors spread across the planet in 47 different countries [source: WNA]. In 2009 alone, atomic energy accounted for 14 percent of the world's electrical production. Break that down to the individual country and the percentage skyrockets as high as 76.2 percent for Lithuania and 75.2 for France [source: NEI]. In the United States, 104 nuclear power plants supply 20 percent of the electricity overall, with some states benefiting more than others.

In this article, we'll look at just how a nuclear reactor functions inside a power plant, as well as the atomic reaction that releases all that crucial heat.
source - http://www.howstuffworks.com

Wednesday, January 19, 2011

What is Bluetooth dial-up networking (DUN)

Bluetooth dial-up networking (DUN) is a wireless internet technology that refers to connecting to the internet using a Bluetooth enabled cell phone as a modem. Bluetooth DUN offers a low band alternative where there are no local hotspots to provide high speed wireless internet access. Bluetooth is a wireless protocol that allows for wireless communication to take place in a Personal Area Network (PAN). It makes use of the frequency hopping spread spectrum to transmit data over short distances from fixed or mobile devices. It is mainly used to exchange information between mobile phones, digital cameras, laptops, printers and many more.
Bluetooth DUN Bluetooth DUN


For you to make use of Bluetooth DUN, you will need a Bluetooth enabled laptop, a Bluetooth DUN capable device such as a mobile phone, a broadband access subscription and supporting drivers for your Bluetooth DUN capable phone. You may need to verify that your laptop indeed has Bluetooth. If your laptop is not Bluetooth enabled, you could make use of a Bluetooth USB adapter or configure it first to allow for Bluetooth connectivity. You may also need to install a Bluetooth program. You then need to use this software to scan for Bluetooth devices. The laptop should be able to recognize all Bluetooth enabled devices within its perimeter. A broadband access subscription is obtained from your Internet Service Provider who also provides you with a username and password that you will use to set up the Bluetooth DUN. A dial-up access phone number is also required. If using a cell phone, the phone must also be Bluetooth enabled.

Once the cell phone is turned on, the laptop should be able to detect it as well as all other devices within its range. Once the cell phone is discovered, depending on your operating System, you will be shown various options to choose from. All you need to do is to look for the dial-up networking available service and select it. Once you have found the service, your Bluetooth adaptor software will allow you to create a dial-up connection. However, it is important to note that not all Bluetooth adaptor software will allow you to create a dial-up and the software you choose is therefore very important for this stage. This scenario has popularly termed the whole process as the Bluetooth dial-up networking hack. The phone may require that you accept or decline the connection request and may sometimes need you to key in a security code. The phone and the laptop will then be paired and a connection formed. The connection is now complete.

Advantages of Bluetooth DUN

1. Can be used as a modem when no other means of connecting to the internet is available.

2. Bluetooth DUN makes use of Bluetooth technology meaning that it benefits from all the advantages that Bluetooth offers such as the fact that Bluetooth does not require direct line of sight connection.

3. Bluetooth DUN can be used on several Operating Systems including Windows XP, Linux and Mac OS