An apparatus includes a processor and a memory. A memory access request is received at a storage cell array that comprises two or more subarrays, each subarray including at least one row of storage cells. In certain embodiments, the polymer comprises a copolymer comprising an acrylamide. Captured images of the vessel are then processed by a programmable device, such as a microcontroller, to determine the levels of materials in the vessel based on the optical characteristics revealed in the captured image. The cap is fitted onto the core wire crimping portion, and which is made of resin or rubber. Additional videos are selected and added to the plurality of stream videos as the user watches videos.