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Author Question: For the electronic motor drive shown, the purpose of the controller is to alter the frequency of the ... (Read 152 times) |
The modern decimal position system was the invention of the Hindus (around 800 AD), involving the placing of numerals to indicate their value (units, tens, hundreds, and so on).
More than 2,500 barbiturates have been synthesized. At the height of their popularity, about 50 were marketed for human use.
The Centers for Disease Control and Prevention has released reports detailing the deaths of infants (younger than 1 year of age) who died after being given cold and cough medications. This underscores the importance of educating parents that children younger than 2 years of age should never be given over-the-counter cold and cough medications without consulting their physicians.
When Gabriel Fahrenheit invented the first mercury thermometer, he called "zero degrees" the lowest temperature he was able to attain with a mixture of ice and salt. For the upper point of his scale, he used 96°, which he measured as normal human body temperature (we know it to be 98.6° today because of more accurate thermometers).
The most destructive flu epidemic of all times in recorded history occurred in 1918, with approximately 20 million deaths worldwide.