Tuesday, November 20, 2007

Fuel Cells, The Future of Power

Electrical energy is today, one of the most essential sources of energy, and since the discovery of electrical generation, man has sought after different and more efficient ways of power generation. Today, one major way of electrical generation being researched on is with Fuel Cells. Fuel Cells promise to be an efficient source of electrical power, giving out pure water as the only byproduct.
But, who invented this Fuel Cell.? It was a Welsh scientist Sir William Robert Grove who put together the first cell, in 1843. His principle was based on the fact that just as when electricity is passed though water, the water splits up into hydrogen and oxygen, the reverse is also possible. This cell was called by Grove, a “gas voltaic battery”. Later it was renamed a Fuel Cell.
In simple terms, a fuel cell is a device that combines the two elements, Hydrogen (H2) and Oxygen (O2), which in turn produces electrical energy. Hydrogen and Oxygen combine to form pure water, which is the only byproduct. Since these cells need hydrogen as the primary “fuel”, they are also called a Hydrogen Cell.
The construction of a fuel cell is similar to that of an electrolytic battery. The only difference is it doesn’t store energy or “run down”. It produces its own energy as long as the necessary fuels (hydrogen and oxygen) are supplied. There are two electrodes, the anode (or the negative terminal) and the cathode (or the positive terminal), separated by a proton conducting polymer. This is basically an electric current insulator. Hydrogen is supplied to the anode, while oxygen is supplied to the cathode.
When hydrogen is supplied to the anode, there is a catalytic reaction, in which hydrogen breaks up into protons (positively charged particles) and electrons (negatively charged particles). The protons pass directly through the polymer to the cathode. On the other hand, the only path for electrons is the external circuit, hence current passes through it. At the cathode, oxygen reacts with the hydrogen protons to form water, either in vapor or liquid form, which is the by-product of the cell. This process continues as long as the fuel is supplied. Oxygen is usually drawn from the external atmosphere.
There are various types of fuel cells out there being researched on. Some of them are given below:
1. Polymer exchange membrane fuel cell (PEMFC):
These cells have a relatively low operating temperature of 600C to 800C, which means it takes less time to reach operating temperature and generate electricity. They are most likely to be used for transportation applications.
2. Solid oxide fuel cell (SOFC):
These are most suitable for large scale stationery generation. The operating temperatures of these cells range between 7000C to 10000C, which means that the material used is rather expensive. These are one of the most stable cells. Also, the heat generated could be used to produce steam to power steam turbines for power generation.
3. Alkaline fuel cell (AFC):
This is one of the oldest designs out there. AFC’s require absolutely pure fuel for functioning, or risk not functioning properly due to contamination. The building cost of these cells is very high.

But why use fuel cells? For a long time, numerous issues and concerns about pollution due to fossil fuels has risen. Fuel cells promise to be a relatively cleaner and less polluting option for power. Right from powering a small bulb, to an automobile, to an entire city, fuel cells provide a solution. In fact, Honda unveiled their first car completely powered by fuel cells, the Honda FCX Clarity (left). Also, fuel cells are very useful as power sources in remote locations, such as spacecraft, remote weather stations, etc. A fuel cell system running on hydrogen can be compact, lightweight and has no major moving parts. Because fuel cells have no moving parts, and do not involve combustion, they are a much more reliable and sturdy source of power. Hence, fuel cells promise a lot for the future.

Thursday, November 15, 2007

Technorati Profile

Apple's lil gem, the iPod Touch

The word iPod is referred to an mp3 player, just as Xerox to a photocopy. It’s the sheer cutting edge technology, together with sleek design that has earned the iPod that rank.
Apple’s newest iPod, the iPod Touch is in a class of its own. Featuring a 3.5 inch touch screen with multi-touch, Wi-Fi connectivity, and a range of other features, it is probably one of the best iPods out there yet.
In the box, along with the iPod Touch, comes the usual Quick Start guide and other booklets, the USB cable, the Earphones, the Dock Adapter. Apple has also included a small plastic stand and a polishing cloth.
The layout of the iPod is very neat. There are exactly two buttons on it – the Sleep/Wake button and the Home button. To the right hand top corner of the iPod, there is a small plastic cover, under which is the Wi-Fi antenna. All other functions are accessed by the touch screen.
The iPod touch features the addition of new features like the Safari web browser and YouTube, the option of adding contacts directly with the onscreen keyboard, clock features and a basic calculator, along with the basic Music, Photo and Video options. There is also an onscreen button to go directly to the iTunes online store.
Music is similar to that of the other iPods, giving you the option of browsing tracks by artists, albums, genres, etc. When turned horizontally, you can browse your music in cover-flow mode.
Video’s play exceptionally well and are more pleasing to view on this big screen than on the other iPods with 2.5 inch screens. You can even watch widescreen movies.
Photos’ are no longer unpleasant to view, with the Touch giving you the option of viewing photo’s in landscape mode as well. Also, with the zoom feature, you no longer need to squint and stare hard to view the little details.
Browsing the net with Safari is quite enjoyable. The onscreen keyboard is rather easy to use. And with the multi-touch function you can zoom into any part of the page you wish to view.
The YouTube feature lets you directly access YouTube. This is very convenient considering the amount of streaming media available on YouTube today.
There are quite a few settings available to adjust and customize your iPod for your usage.
At any time, while using any feature, pressing the home button gets you directly back to the home screen. The home button is a little hard to press though.
One thing disappointing about the iPod touch is the absence of the Notes feature. Also, the inclusion Google Maps feature would have been welcome, considering Wi-Fi is available.
In conclusion, the iPod Touch is a beautiful gadget, with a blend of cutting edge technology and beautiful design. Its well worth the money.