Certain embodiments of the present disclosure provide an acoustic inlet barrel of an engine. The acoustic inlet barrel may include an inner barrel configured to provide a boundary for directing airflow through the engine. The inner barrel may include an inner face sheet separated from an outer face sheet by an acoustic core. The inner barrel may include a plurality of elongated, non-circular perforations formed through the inner face sheet.

Provided is a machining apparatus capable of improving the positioning accuracy of a machining tool as compared to conventional machines. A machining apparatus 1 includes a rotating tool, a machining tool provided on an outer periphery of the rotating tool, and a spindle head adapted to rotatably support the rotating tool. The machining apparatus includes a driving portion configured to move the spindle head in a direction perpendicular to an axis of rotation R of the rotating tool, a position sensor configured to measure a position of the spindle head on a plane perpendicular to the axis of rotation R, and a control unit configured to control the driving portion so as to move the machining tool in a direction perpendicular to the axis of rotation R of the rotating tool on the basis of the position of the spindle head.

An apparatus for more effectively extracting energy resources from underground reservoirs and a method for manufacturing the same. The apparatus is a perforating gun that includes scallops shaped such that charges that are displaced from their original location nevertheless remain located below the scallop, which increases the effectiveness of displaced charges when detonated. In addition, the scallops are created using a method that enables the entire scallop to be of a uniform thickness, which also increases the effectiveness of charges detonated beneath the scallop.

Certain embodiments of the present disclosure provide an acoustic inlet barrel of an engine. The acoustic inlet barrel may include an inner barrel configured to provide a boundary for directing airflow through the engine. The inner barrel may include an inner face sheet separated from an outer face sheet by an acoustic core. The inner barrel may include a plurality of elongated, non-circular perforations formed through the inner face sheet.

Provided is a machining apparatus capable of improving the positioning accuracy of a machining tool as compared to conventional machines. A machining apparatus 1 includes a rotating tool, a machining tool provided on an outer periphery of the rotating tool, and a spindle head adapted to rotatably support the rotating tool. The machining apparatus includes a driving portion configured to move the spindle head in a direction perpendicular to an axis of rotation R of the rotating tool, a position sensor configured to measure a position of the spindle head on a plane perpendicular to the axis of rotation R, and a control unit configured to control the driving portion so as to move the machining tool in a direction perpendicular to the axis of rotation R of the rotating tool on the basis of the position of the spindle head.

Method and apparatus for adapting a Standard End Cap assembly of a perforating gun to function as a Tubing Conveyed Perforating end cap assembly of a perforating gun. The method includes inserting an inner end cap into an opening of a Standard End Cap, and positioning the inner end cap such that the inner end cap and Standard End Cap become interlocked without the need of a snap ring. The apparatus includes an inner end cap that may include anchors or receivers, and a Standard End Cap that may include anchors or receivers, such that the anchors in one component correspond to the receivers in the other component to facilitate the interlocking of the two components.