Laptop

A laptop or notebook (in English: laptop or notebook) is a mobile or portable personal computer, usually weighs between 1 and 3 kg. Laptop computers are able to perform most of the tasks performed by desktop computers, also called "tower" with similar capacity and with the advantage of reduced weight and size; it also joined with the ability to operate for a specified period without being connected to a power grid.

The word laptop translated into Castilian means: lap (lap) and top (above) that is, a computer that can rest on the legs.

The first laptop was considered as the Epson HX-20 developed in 1981, from which the great benefits for the work of scientists, soldiers, businessmen, and other professionals, who saw the advantage of being able to take with them were observed your computer with all the information they need from one place to another.

The Osborne 1 came to the commercial market in April 1981 in the format currently distinguishes them, but then they were extremely limited, even for the technology of the time.

In 1995, with the arrival of Windows 95, selling laptops it increased significantly, and now exceeds the sales of desktops.

In the third quarter of 2008, sales of laptops for the first time exceeded those of desktop computers, according to research firm

Radio Communications

Radio communications is regulated by the International Telecommunication Union (ITU) has established a radio regulations in which we read the following definition:

Radio waves or radio waves "electromagnetic waves of frequencies arbitrarily lower than 300 GHz, propagated in space without artificial guide"; they are between 9 kHz and 300 GHz which corresponds to wavelengths of 33 km 1 mm1.
Frequency waves below 9 kHz are radio waves, but are not regulated.

Waves above 300 GHz are classified into the infrared waves as the technology associated with their use is currently optical and not electrical type, though this border is artificial because there is no difference in nature between radio waves , light and other electromagnetic waves waves (eg microwave, radar, etc.).

Many regulations concerning frequency sharing for different uses, some uses or exposure of workers to certain electromagnetic fields, via européenne2 regulations.