An electronic circuit on a semiconductor substrate having isolated multiple gate field effect transistor circuit blocks is disclosed. The multiplicative AGC circuits attenuate acoustic signals having a constant background level without the loss of speech intelligibility. The differences between the anticipated and desired state changes may be weighted based upon a predetermined criteria, such as the importance of the respective states andor the weight to be attributed to outliers. In yet another aspect, the invention is a system for supplying a gas-liquid vapor to a process tank comprising: the apparatus of the present invention; gas supply means adapted to supply the gas to the tube; liquid supply means adapted to supply the liquid to the chamber; and gas-liquid transport means adapted to carry the gas-fluid vapor from the apparatus to the process tank. Responsive to identifying a predefined first customer type for the electronic-commerce order, the electronic-commerce order is transferred from the predetermined temporary readwrite cylinder to a selected cylinder within a set number of cylinders from the predetermined temporary readwrite cylinder. In one embodiment, the imaging gantry can translate, rotate andor tilt with respect to a support base, enabling imaging in multiple orientations, and can also rotate in-line with the support base to facilitate easy transport andor storage of the device.