- published: 11 Jul 2014
- views: 181443
Koma or KOMA can refer to:
Radio is the transmission of signals through free space by electromagnetic waves with frequencies significantly below visible light, in the radio frequency range, from about 3 kHz to 300 GHz. These waves are called radio waves. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space.
Information, such as sound, is carried by systematically changing (modulating) some property of the radiated waves, such as their amplitude, frequency, phase, or pulse width. When radio waves strike an electrical conductor, the oscillating fields induce an alternating current in the conductor. The information in the waves can be extracted and transformed back into its original form.
The etymology of "radio" or "radiotelegraphy" reveals that it was called "wireless telegraphy," which was shortened to "wireless" in Britain. The prefix radio- in the sense of wireless transmission, was first recorded in the word radioconductor, a description provided by the French physicist Édouard Branly in 1897. It is based on the verb to radiate (in Latin "radius" means "spoke of a wheel, beam of light, ray").
Slavery is a system under which people are treated as property to be bought and sold, and are forced to work. Slaves can be held against their will from the time of their capture, purchase or birth, and deprived of the right to leave, to refuse to work, or to demand compensation. Historically, slavery was institutionally recognized by many societies; in more recent times slavery has been outlawed in most societies but continues through the practices of debt bondage, indentured servitude, serfdom, domestic servants kept in captivity, certain adoptions in which children are forced to work as slaves, child soldiers, and forced marriage.
Slavery predates written records and has existed in many cultures. The number of slaves today is higher than at any point in history, remaining as high as 12 million to 27 million, Most are debt slaves, largely in South Asia, who are under debt bondage incurred by lenders, sometimes even for generations.Human trafficking is primarily used for forcing women and children into sex industries.