Wednesday, May 20, 2009

Video Teleconferencing Technology

Video Teleconferencing technology is a new technology that has been invented to give a cutting edge to your business! The Video teleconferencing technology allows two or more persons, present at different locations to interact with each other for business purposes (with the help of audio and video transmissions). The video conferencing technology is gaining huge popularity day by day because it can be used for a variety of purpose such as teaching lessons, conducting meeting and seminars!

The teleconferencing technology allows data to come in your system through phone lines and internet connections. The video teleconference system includes the following components: video input, video output, audio input, audio output and data transfer. The core technology that a video teleconference system uses is the digital compression of the audio and video streams in real time. It has been found that compression rates of up to 1:500 can be achieved in this system.

The resulting digital stream of 1s and 0s is further subdivided into labeled packets, which are thereby transmitted through a digital network of some or other kind. In order to receive the compressed bits of information, you need to have a system in place which can handle the bandwidth required for the conference. It is quite easy to set up a system for receiving the information and most of the people generally use their computers since much of the information required to be saved or shared during the conference can be stored here.

In order to send some image or data from your system, you need to have a web cam or video camera. Simple web cams are quite cheap and easy to install but you may get an expensive video recorder installed if you want very good quality video conferencing. Simple web cams do not have the bandwidth to transfer information at a high quality which you may be able get with more costly equipment. However, expensive video cams are not required everywhere, so you can get away with them.

Video teleconferencing is a very effective technology and is helping lots of companies to stay abreast with the latest knowledge and projects. The use of video teleconferencing technology is helping the smaller companies to stay competitive with the larger ones and also helps them to lower their overhead and keep their costs down, which can even benefit the consumer by keeping prices from rising!

So, you can see that video teleconferencing technology is very profitable to the companies and its' popularity is increasing day by day. I hope that more inventions like this continue to happen and ease our lives!

Wednesday, May 13, 2009

Hydrogen Fuel Cell

The hydrogen fuel cell works on the basis of electrolysis process. It generates electricity with fuel on the anode side and the oxidant on the cathode side and they react in the presence of electrolyte. The reactants which are the input flows into the cells and the reactant products flow out of it while the electrolyte remains inside it. The hydrogen fuel cell is just like the water fuel cell which was a failure. However the hydrogen fuel cell is a success. The fuel cells can run continuously if the input is maintained properly.

Hence the hydrogen fuel cell is just like the petrol engine and I must tell you that it works fine as well. However the fuel cells are different from the electrolytic cells as they consume the reactant from the external source, which requires a thermodynamically open system. Many combinations of the fuel and the oxidants are possible. For example the hydrogen cell uses the hydrogen as the fuel and oxygen as the oxidant. The other combinations are hydrocarbon and alcohol as well as chlorine and chlorine dioxide.

The fuel cell works with the help of electrolysis. Up till now you must have understood the use of reactant as well as oxidants. However you will have to understand one more thing and that is catalysis. The fuel cell works with the help of catalysis which helps in separating the electrons and protons. Now you must know that the electric current flows in the direction opposite to the flow of the electron. I must say that the electron flow is maintained with the help of catalysis which separates the electron and proton and hence the electrons start moving in one direction and hence the electricity is generated.

A typical hydrogen fuel cell produces about 0.6 to 0.7 volts of voltage. However this cell does not obey the ohms law. You must know that according to Ohms law the voltage is directly proportional to the current. However this is not the case with the hydrogen fuel cell. In case of the hydrogen fuel cell the voltage is found to go o decreasing as the current starts increasing.

The reason behind the decrease in the voltage is because of the facts that are as follows:
  1. Activation loss
  2. Ohmic loss: (due to the resistance of the cell components and interconnect.)
  3. Mass transport loss (due to the depletion of the reactants at the catalyst site.)
Hence it is a general observation that the hydrogen fuel cell do not obeys Ohms law. In fact all the electrolytic cells do not obey the ohms law and hence hydrogen fuel cell which is also a kind of electrolytic cell does not obey the ohms law.