Abstract: A method to remediate a release of one or more acidic materials, by supplying a powder composition comprising a polyacrylamide, and disposing that powder onto a liquid spill comprising one or more acidic materials.

Abstract: A method to remediate a release of one or more acidic materials, by supplying a powder composition comprising a polyacrylamide, and disposing that powder onto a liquid spill comprising one or more acidic materials.

Abstract: A control system for a multiphase induction motor includes microcontroller control means providing a variable frequency signal and deriving high side/low side phase signals from the variable frequency signal. Power is applied from an AC/DC converter to the motor by an output drive bridge with three pairs of high side/low side semiconductor switches, one pair for each phase. The high side and low side phase signals are applied through high side/low side driver means to control the switches and effectively apply a quasi-square waveform to the motor windings. The motor and the control system electronics are protected from excessive current levels by current sensing means. When the current exceeds a predetermined level, the microcontroller limits the power drawn by the motor by ramping down the variable frequency to lower the speed of the motor. In case the motor or control electronics overheat, a temperature sensor is monitored by the microcontroller to shutdown the motor.