Abstract: An apparatus for perforating a subterranean formation comprises a first perforating gun (33b) having a box end (112) having a nose, a second perforating gun (33a) having a pin end (118) having a shoulder (124); and an alignment assembly. The alignment assembly includes internal threads formed on the box end, external threads formed on the pin end, and an alignment member (120) positioned between the box end nose and the pin end shoulder. The internal threads and the external threads are specified to form an angular alignment between the first perforating gun and the second perforating gun within a first specified angular tolerance. The alignment member has at least one characteristic selected to vary the angular alignment within the first specified angular tolerance without degrading a locking force connecting the first perforating gun to the second perforating gun.

Abstract: An insulating layer (5) and a conductive seed layer (6) are applied to a substrate (1) in a simple process. A photo resist with palladium chloride are provided in a bath for electrophoretic deposition onto the substrate. The photo resist is an insulator and the palladium chloride is a catalyst. The layer is heated with UV to cure it. The layer is plasma etched to expose more of the palladium chloride, which acts as a catalyst for electrodes plating of the conductive seed layer. A thicker conductive layer (7) is then electroplated onto the seed layer. These steps may be repeated for successive insulating and/or conductive layers.

Abstract: A process of forming a material such as a waveguide with at least two regions of differing refractive indices comprising the steps of: (a) providing an amount of a gelable composition comprising at least one gelable component in a desired form; (b) exposing the gelable composition to conditions which partially gel the gelable composition so that an amount of ungelled material remains; (c) exposing at least one discrete region of the partially gelled product of step (b) to conditions which induce more complete gelation of the partially gelled gelable composition so that more of the ungelled material is incorporated into the gel structure in the exposed regions than in non-exposed regions; and (d) removing material not incorporated in the gel structure at least from the non-exposed region. A second component may additionally be provided, the second component being selected to impart a higher or lower refractive index to that part of the material in which it is incorporated.