An acoustic barrier that achieves excellent noise insulating properties, and is relatively thin and relatively light in weight includes a flexible thermoplastic barrier layer having a plurality of apertures defining a latticed structure which includes apertures for pass-through components and non-pass-through apertures. A flying disc is disposed adjacent to the first charge of PBX-9407. The ACDC power converter also includes a switching resonant stage which is directly coupled to the output of the input rectifier stage. During periods of natural aspiration the ejector pump can be by-passed to reduce flow impedance. In one or more embodiments, the enclosure includes cam driven mounting clamps that allow the enclosure to be quickly and easily secured to a table top or other mounting surface. or higher without substantially letting the solvent out of the reaction system.