A method for sputtering a thin film protective layer with improved durability is disclosed. A sting is iterated to produce a compression sequence relative to an alphabet having symbols associated with the string. A differential ultrasonic waveguide cure monitoring probe in direct contact with the material to be cured and providing in situ monitoring of the cure process to enable assessment of the degree of cure or cure level in a non-cure related signal variances independent calibrated response manner. The sealing surfaces of the venting plug body are molded by a single plate such that no mold parting line results along the sealing surfaces, while the coupling structure is molded by plurality of mold components such that a mold parting line results in the vicinity of the coupling structure. The nonvolatile memory device is configured to access a first physical sector corresponding to the physical address, and, when a data delete command is provided from the host to the memory controller to delete first data that is stored in the first physical sector, the memory controller delays an erase andor merge operation for the first physical sector in which the first data is stored. The method further comprises delivering a microbubble therapeutic compound from the ultrasound catheter to the vascular occlusion during a first treatment phase.