A method for collapsing a microbubble includes applying stimulation to the microbubble during the gradual decrease of the its size. From the delay and loss measurements, analytic values for the voice quality impairment caused by delay and by network loss, respectively, are established. The foldable filter includes first and second frame sections connected by the hinge and pleated filter material that includes at least one pleat edge extending generally parallel to a hinge axis. In accordance with an embodiment, instead of or in addition to JMS, the system can use a distributed in-memory data grid, such as Oracle Coherence, to provide queuing functionality. Also, the negative liquid crystal that is not affected by the vertical electric field is used such that a mode change speed and response speed may be improved. The jet is injected into a draft tube mixer positioned in a fluid bed of hot coke particles suspended in steam and contained within a fluid coking reactor.