Caffeine Information. Caffeine is naturally found in cocoa beans, coffee beans and tea and is synthetically produced for use in certain medications and in beverages. This substance is a stimulant drug that quickly enters the bloodstream and affects the brain.
Frequency Range Chart. The radio spectrum refers to the section of the electromagnetic spectrum that holds all possible radio frequencies ranging from 3 kHz to 300 GHz.Radio frequency is used for radio communication technology, wireless networks and telecommunication systems.he radio spectrum refers to the section of the electromagnetic spectrum that holds all possible radio frequencies ranging from 3 kHz to 300 GHz. Radio frequency is used for radio communication technology, wireless networks and telecommunication systems.
Hearing range describes the range of frequencies that can be heard by humans or other animals, though it can also refer to the range of levels. The human range is commonly given as 20 to 20,000 Hz, though there is considerable variation between individuals, especially at high frequencies, and a gradual loss of sensitivity to higher frequencies with age is considered normal. Sensitivity also varies with frequency, as shown by equal-loudness contours. Routine investigation for hearing loss usually