The present disclosure relates to a plasma reactor for plasma-based gas conversion comprising a pin electrode extending along a longitudinal axis from a first end to a second end, an opposing electrode opposing a discharge tip of the 10 pin electrode, a plasma chamber for confining a glow discharge plasma, and an electrically-insulating body that comprises an inner bore extending along the longitudinal axis from a bore entrance to a bore exit. The second end of the pin electrode comprises a discharge tip. The pin electrode penetrates the inner bore from the bore entrance and extends at least partly through the inner bore and a15 radial wall of a portion of the inner bore located between the second end of the pin electrode and the opposing electrode, is radially delimiting the plasma chamber. The plasma reactor is further configured for varying an electrode separation distance between the discharge tip of the pin electrode and the opposing electrode.

A continuous nanoparticle processing system includes a continuous flow path between an inlet and an outlet. The system has at least one sensor positioned to generate a signal indicative of a quality attribute of nanoparticles within the flow path, at least one actuator coupled to the flow path; and a controller operatively coupled to the sensor and the actuator and configured to, during operation, adjust the actuator in response to the signal to maintain the quality attribute of the nanoparticles within a target range while the nanoparticles traverse the flow path. A computer program product is disclosed.

The method can include receiving a baseline signal curve, operating a thermal reactor, measuring a signal, optionally determining a state (e.g., state of health) of the thermal reactor, and controlling the thermal reactor based on the signal. The method can include receiving (e.g., determining, measuring, etc.) a resistance-temperature and/or resistance-time curve; operating a thermal reactor comprising resistively heating a porous catalytic element; measuring an electrical signal (e.g., resistance, current, voltage, etc.) of the thermal reactor; optionally inferring a temperature of the thermal reactor based on the electrical signal and the resistance-temperature; and controlling the thermal reactor based on the electrical signal. The system can include one or more of a reaction module (e.g., an electrical coupler or electrode and catalytic element, etc.), inlet and outlet valves, power source, electrical feedthroughs (e.g., leads, supports, etc.), sensors, and computing system (e.g. controller).