Abstract: An apparatus and method is provided to reduce interference resulting from activation of explosive devices. One type of interference is charge-to-charge interference, and another type of interference is pre-shock interference between a detonating cord and an explosive, such as a shaped charge. To reduce interference, one or more shock impeding elements are placed proximal one or more explosives to impede propagation of shock caused by detonation of the explosives. The shock impeding elements include a porous material, such as a porous liquid or solid. In another arrangement, a shock barrier may be positioned between a detonating cord and an explosive to reduce pre-shock interference. In yet another feature, an encapsulant may be provided around one or more shaped charges to enhance structural support for the shaped charges.

Abstract: Apparatus for measuring multiphase fluid flows comprising first and second sections each comprising a flow passage having means for making a dynamic pressure measurement on the multiphase fluid flow therethrough, the geometry of the first and second sections differing so as to affect a relationship between void fraction and velocity for the phases in a known manner. The difference in geometry between the two sections can be in the area of the flow passages or in the direction of flow relation to gravity. A method of measuring multiphase flows comprising the steps of:a) directing the flow through a first flow passage including means for making a dynamic pressure measurement;b) measuring a pressure drop across said means;c) directing the flow through a second flow passage including means for making a dynamic pressure measurement;d) measuring a pressure drop across said means; ande) calculating the composition and flow rates of the phases from the measured pressure drops.