The invention relates to an electrode material and a composite electrode including same. The tubular element has a proximal end and a distal end adapted to be inserted into a body cavity. The single space parking meter may read account information from the payment card using the card reader and receive an indication of the monetary value to load or reload onto the parking card. The character sequence is sent to a coprocessor. Also disclosed is a piezooptic device which includes a first element of porous crystalline material, a second element being attached to, or integrally formed with, the first element, and a light source, such that subjecting the first element to light originating from the light source results in a strain induced by the first element on the second element. The invention also includes optical methods for utilization within a deposition apparatus for assessing the alignment of a substrate within the apparatus andor for assessing the thickness of a layer of material deposited within the apparatus.