Introduction:
The daily use of electronic equipments are known as consumer electronics and includes TV, telephone, DVD, CD, PC, laptop etc. These equipments are manufactured throughout the world. With the advancement in electronic engineering at a continuous pace, a number of new variety electronics items flood into the market every year and the cost the existing products reduces continuously and it is one of the biggest advantage of consumer electronics industry.
Electronic waste is one of the problems associated with these electronic item and many manufacturers are now planning to deal with these waste.
Semiconductor:
All electronic devices use semiconductors and without these semiconductors none of the electronic device is complete. Semiconductor behaves like an insulator at absolute zero (-273 degree centigrade) and can be distinguished from conductor that at this temperature the outermost filled electron energy band is completely filled in a semiconductor compare to the conductor in which the band is partially filled.
At room temperature semiconductor show a very small electrical conductivity much lower than that of conductor.
Doping in semiconductor:
Most common semiconductors used for electronic devices are silicon and germanium. Although some other conductors such as iridium phosphide, gallium arsenide and mercury cadmium telluride are also used.
A pure semiconductor also known as intrinsic semiconductor, when doped with electron rich element e.g. arsenic or electron deficient element e.g. boron in very small quantity, its conductivity increases and the resultant conductor is known as extrinsic conductor. My doping arsenic (electron rich) and boron (electron deficient) in silicon, we get n-type (negative type) and p-type (positive type) semiconductor devices.
We may create a p-n junction by doping different element in different region of semiconductor and the device is known as diode. Similarly we can create p-n-p or n-p-n junctions and the device is known as triodes.
Electronic Devices
(a) Television:
It is a device by which we can receive moving pictures and sounds over a distance. The whole transmission and receiver systems require the following inputs.
1.Camera for live images or flying spot scanner for transmission of films and sound source.
2.Transmitters for transmitting both images and sounds.
3.Receiver systems for receiving these signals.
4.Display device, which is either CRT, Rear projection, LCD or plasma. To display the signal in the forms of images and sounds.
(b) Telephone:
It is the device for communicating by which two persons can send and receive sound signals over a distance. The system requires the following inputs.
1.The telephone equipment, which converts sound signals to electrical signals and electrical signals to sound signals.
2.Central exchange from where the subscribers are interconnected.
3.Wiring for connecting all the subscribers.
(c) Calculators:
It is a device used for carry out various mathematical calculations. The input required for calculator are as given below.
1.Power source (battery or solar panel).
2.Display device (LED or LCD)
3.Keypad containing all functions and numbers.
4.All electronic circuit devices.
Electronic Waste:
These are the waste electronic devices and if properly utilized may be valuable secondary raw material source for various electronic equipments and if thrown out may act as toxic due to presence of various toxic materials including lead, mercury, cadmium, arsenic etc. uncontrolled burning of these materials may also cause environmental problems.
Electronic waste is sometimes illegally sent to other countries for processing. However, due to complexity and difficulties in recycling, e-waste will remain an issue for the coming days.
Monthly Archive for March, 2010
In a move towards creating a suitable environment for secure electronic transactions, the Sultanate of Oman has issued the e-Transactions Law formalised by the Royal Decree 69/2008.
This is the first law for legalising electronic transactions in Oman which can be defined as any contract, agreement or communication in this regard to be fully or partially implemented by electronic means as electronic messages.
The formulation of this law begins a new era for Oman, where a truly e-enabled society evolves in the realisation of the digital society of Sultanate. It is a major milestone in the implementation of the national IT strategy by the Information Technology Authority (ITA) of Oman.
The e-transactions law consists of nine sections and combines 54 articles, developed and refined over a period of three years. ITA along with a few other government entities and a private law firm have compiled this law based on studies about the United Nations Commission on International Trade Law (UNCITRAL), Organisation for Economic Cooperation and Development (OECD) guidelines on the Protection of Privacy and Trans-border Flows of Personal Data, and e-laws of several countries like the USA, Europe, France, Ireland, Malaysia and Tunisia.
The e-transactions law of Oman legalises the use of digital signatures in electronic commerce and communications through letters, emails, etc. Organisations wishing to introduce digital signatures for their use must be approved by the Information Technology Authority through a formal process.
Dr. Salim Al Ruzaiqi, CEO of Information Technology Authority (ITA) has pointed out that one of the main purpose of this law is to facilitate electronic transactions which are vital to e-government and e-commerce applications in Oman. In order to support such transactions, any contract, agreement or communication carried by electronic means as electronic messages is considered legally valid through this law. It regulates the transfer of electronic data and messages through various electronic channels such as the Internet and control changes made to data.
For creating the regulatory environment, the law has strict penalties for anyone misusing electronic systems, the applications and the data resident in them by punishing criminal acts using electronic systems and data like hacking into computer systems, unauthorised capture or tampering of data, etc.
ITA is saying that through this law it aims to consolidate public trust in the safe use of e-transaction, messages and records while assuring adequate protection for privacy of data of individuals involved in such e-transactions.
Promotion of this law sets up unified rules, regulations, and standards of authenticating electronic messages and records. By building trust and security, it will reinforce the development of the e-transaction at the national, Gulf, and Arabic domain by using the e-signature and e-transactions. The use of electronic signatures in electronic commerce set forth a common legal framework for electronic authentication over the Internet or other electronic media. It also will play a pivotal role in forming contracts, carrying out business; assisting people work together co-operatively and underpin many forms of electronic collaboration.
As a comprehensive law it gives credibility to electronic information sharing, while taking the issue of information and communication security to higher levels of authentication, integrity and privacy.
The law provides for encryption as a means to protect e-transactions in order to ensure confidentiality of information or data of the message, to verify the originator, and to prevent others from getting information or data messages so as not to reach the addressee or to corrupt them.
Government entities can now use electronic records and digital signatures in tendering systems; license request processing and taxation systems can also accept fees or any payments electronically.
Protection for adequate privacy in matters related to personal data held in computer systems and processes for enabling electronic transactions is assured by the new e-transactions law of Oman. The law rests the responsibility of protecting electronic systems and data on the entities that manage these electronic systems and the authorised entity that issues valid digital signatures.
The necessary regulations and decisions for the law, which will come into effect three months after its publication in the Government Gazette, would be issued by the Minister of Commerce and Industry.
To make a complete change over in the look of your back yard or front yard you could incorporate the use of rocks to make a vast difference to the entire landscaping. Placed in strategic places with plants and shrubs around it a rock can be a piece of artifact in your garden.
Different kinds of rocks
When you plan to add rocks to your landscaping don’t just think of the ordinary rocks you find lying around on a sandy beach or at the base of a mountain; you can get rocks in various shapes and sizes. Different stones with varying shades and colors are also available to enhance your rock garden, in the garden stores. Based on the size of your garden area and the landscaping plan that you have decided on, you can buy suitable rocks or stones to create a wonderful vision.
How to go about your rock garden
The scheme of the landscape is what will give the basis of placing your rocks around. Make the placement of rocks look natural and at the same time stand out and not get covered by foliage and plants that you place near it. It should blend in with the scenery and not look as though you have put it there to either cover up some area or just to make room for the rock. Look at the rocks in their natural terrain and see how they blend in with the rest of the scenery. Get a balanced and effective look with the placement of the rocks and not a crowded one.
Another aspect that you should pay attention to is the natural look of the layout. If you can take the trouble to bury part of the rock in the soil not only will it look more natural, it will also be firm in its location and not move around because of the weather conditions or people moving it around; this way it will seem that the rock was already there as part of the area. If you have a bigger rock you will have to bury it deeper than a small one. Visualize how a rock looks in its natural surroundings and bury it in the same way in your yard.
To bury a rock you would have to dig a pit that is as big as your rock in the ground which is about 4 to 6 inches deep and place your rock in it. The next step would be to put some soil around it and make it firmly embedded in the ground. This gives it a natural look and also keeps it firmly in place. Do this with all the rocks that you want to place around the yards.