The invention is a discharge electrode in an electrostatic precipitator having a power supply connected to at least one collection electrode and a flow of gas across the collection electrode. A base station control device controls each base station. In a method according to the invention, a biological object is imaged by emitting an unfocussed ultrasonic energy wave front, reflecting at least a portion of the ultrasonic energy wave front from the object, altering a direction of the ultrasonic energy, detecting that energy, and using the detected energy to create an image of the object. Fabrics in the second section are not compressed and are not joined other than to prevent slippage of the fabrics relative to one another. This externally supplied power allows the required cooling capacity thermal electric cooling modules to be used to significantly lower the ambient air temperature.