A subsea riser assembly connects two tubular members with axial movement of an outer sleeve. The superabsorbent polymer particles are separated from the solidified thermoplastic composition by using a supercritical fluid comprising carbon dioxide, propane, or mixtures thereof. The facility may then determine whether it is appropriate to deliver an advertisement to the user and select an advertisement for delivery. Hence, measuring such a characteristic of the active layer allows variations in the carrier occupancy of the quantum dots to be determined. A current in the write head is dynamically adjusted to compensate for variations in the components and environment by periodically measuring the writability of the drive and adjusting the write current such that the parameter stays within predetermined criteria. The device thus enables effecting a change in said electronic property that results in a detectable change in the optical response of the layer structure.