An ultrasound imaging system includes a transducer array, with an array of transducer elements that transmits an ultrasound signal and receives a set of echoes generated in response to the ultrasound signal traversing a flowing structure. This reduces the amount of adsorbent required in the beds for a given feed rate while continuing to provide product at an acceptable product purity, and has the desirable effect of reducing the capital cost of the process equipment required for a given volumetric production rate. Another arrangement is disclosed for holding collector to emitter voltage constant for intermediate transistors resulting in improved gain accuracy and linearity. A resilient, elastic strip or band may be positioned between the hair blow dryer outlet and the concentrator nozzle attachment inlet. The focal-length value determined by this procedure, resulting in a good fit between the analytical curve and the experimental data, is equal to half the radius of curvature of the micromechanical mirror.