Fifty years ago, Keldysh introduced an important idea. Treating both gases and solids on the same footing, he showed that strong-field ionization—valence-band to conduction-band transitions in ...

Harmonics of the 60 Hz power frequency has been around for a long time. It was observed on transmission systems in the early 1890s and was associated with voltage and current waveforms. As equipment ...

The power quality of electrical distribution systems has a drastic effect on power regulation and consumption. Power quality includes all aspects of events in the power system that deviate from normal ...

In electrical heating applications, resistive heaters are powered through phase angle-controlled SCR/triac circuits to vary the applied voltage/power to maintain the required temperature. Phase angle ...

NEW BERLIN, Wis. - "If you claimed that the sole purpose of a variable speed motor drive was to increase energy efficiency, it would be no exaggeration, of course," said Mike Olson, HVAC sales manager ...

Musical instruments and throats create different notes by making the air around them vibrate at particular frequencies (check out part one to find out how they do it). When you pluck the A string on a ...