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A comment on US Employee in China Suffers Brain Injury in Case Recalling Cuba Sound 'Attack'. Parent comment

Re:US Employee in China Suffers Brain Injury in Case Recalli... by gruez on Wednesday May 23, 2018 @02:20PM (#17136600)
but if you have two 60db transmitters, the max you can produce (from my understanding) with constructive interference is 70db , since db is logarithmic. so does that mean the transmitters in question were already transmitting at 100+db?
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Re:US Employee in China Suffers Brain Injury in Case Recalli... by jimrandomh on Wednesday May 23, 2018 @03:01PM (#17137086)
Some ultrasound devices operate at power levels that would be dangerous by themselves if they were at a different frequency. Eg the article mentions "One advertised jammer emits 120-dB ultrasonic interference at a distance of 1 meter".
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Re:US Employee in China Suffers Brain Injury in Case Recalli... by jhpankow on Wednesday May 23, 2018 @02:43PM (#17136851)
2x 60dB is 63dB.
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Re:US Employee in China Suffers Brain Injury in Case Recalli... by basementcat on Wednesday May 23, 2018 @02:57PM (#17137032)
If the two sources are coherently phased up you can get 66 dB.
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Re:US Employee in China Suffers Brain Injury in Case Recalli... by gruez on Wednesday May 23, 2018 @02:54PM (#17137004)
yeah sorry, got apparent loudness and amplitude confused.
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Re:US Employee in China Suffers Brain Injury in Case Recalli... by jcims on Wednesday May 23, 2018 @05:02PM (#17138253)
While true, the energy delivered to the subject depends on the radiation pattern. A 100W light bulb can help you pick out clothes in the closet, a 100W laser can cut steel (sorta).
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Re:US Employee in China Suffers Brain Injury in Case Recalli... by fh973 on Thursday May 24, 2018 @02:23AM (#17141523)
A 100W laser cuts acrylic and wood, not steel. This is the power level of hobbyist laser cutters.
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Re:US Employee in China Suffers Brain Injury in Case Recalli... by jcims on Friday May 25, 2018 @05:54PM (#17158334)
That's in part why I said 'sorta', but Kern actually sells a 150w CO2 laser that they will support for metal cutting applications (2mm for mild steel).

I'll conveniently ignore the O2 assist for the sake of counterpoint. :)

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