There is provided a tube connector for connecting between a fluid sampling tube and a fluid analyzer, the tube connector includes an end face adapted to identify the tube connector, said end face comprising a reflecting surface having one or more reflective regions adapted to reflect light at a predetermined range of wavelengths. When placed in a subterranean well having at least one casing string, cement sheaths with linear thermal-expansion coefficients similar to that of the casing will be subjected to lower compressive and tensile stresses during downhole-temperature changes. The execution context identifies operations executed by the computing device, signal strength, and other data describing the associated time period. The robot includes a pad sensor to sense a feature on the pad and to generate a signal based on the feature, which is defined in part by a cutout on the card backing. Recovery of data on the primary volume based on the local secondary volume is conducted when necessary by applying the journal logs to the old data without suspending the synchronous mode between the primary and remote secondary volumes. Such a structure can be realized, for example, by changing a thickness of a transparent electrode which is a lower electrode of the element.