A method and apparatus for allowing a customer to purchase or otherwise receive a benefit during a first transaction that will be redeemed by the customer or provided to the customer at a later time or during a future transaction for the purchase, rental, lease, etc. Measurement of current through the membrane addresses ion channels through the membrane at the location illuminated by the light source. The method may include introducing a cement composition into the subterranean formation, wherein the cement composition comprises cement, a nano-particle, latex, and water. A transmission and a phase are altered in a 2D simulation based on this first size until a shape dependent transmission and a shape dependent phase allow the 2D simulation to substantially match the 3D simulation.