Abstract: A Kelly bar apparatus includes a plurality of concentric tubes in a telescoping arrangement having either a locking feature provided by a series of keys and notches that interlock selectively, or one or more blocking tabs that prevent complete telescopic extension of at least one of the tubes when the tubes and associated keys are in an unlocked position, or both. Related subterranean bore drilling systems and drilling methods are also described.

Abstract: An aircraft engine includes an aircraft engine controller configured to detect an actual peak exhaust gas temperature of a cylinder assembly. The aircraft engine controller detects an intersection between a first function representing a relationship between a set of rich exhaust gas temperature signals and a corresponding set of rich fuel-air ratio values and a second function representing a relationship between a set of lean exhaust gas temperature signals and a set of lean fuel-air ratio values. Based upon the intersection between the first and second functions, the engine controller detects an actual peak fuel-air ratio value for the cylinder assembly and can determine if a correction in the fuel-air ratio of a fuel-air mixture provided to the cylinder assembly is required. Accordingly, the engine controller provides each cylinder assembly of the aircraft engine with an accurate fuel-air mixture to allow for operation of the engine with optimal fuel economy.

Abstract: An aircraft engine includes an aircraft engine controller configured to detect an actual peak exhaust gas temperature of a cylinder assembly. The aircraft engine controller detects an intersection between a first function representing a relationship between a set of rich exhaust gas temperature signals and a corresponding set of rich fuel-air ratio values and a second function representing a relationship between a set of lean exhaust gas temperature signals and a set of lean fuel-air ratio values. Based upon the intersection between the first and second functions, the engine controller detects an actual peak fuel-air ratio value for the cylinder assembly and can determine if a correction in the fuel-air ratio of a fuel-air mixture provided to the cylinder assembly is required. Accordingly, the engine controller provides each cylinder assembly of the aircraft engine with an accurate fuel-air mixture to allow for operation of the engine with optimal fuel economy.

Abstract: A slide caliper assembly comprises a caliper including a shaft defining a gaging surface. A first jaw is coupled to and a second jaw is slidably coupled to the shaft. Each jaw defines a gaging surface. One of the jaws is adjustably pivotable relative to the shaft about a pivot axis coinciding with an intersection of the gaging surface of the shaft and another axis extending along the associated gaging surface of one of the jaws. A case houses the caliper, and has a plurality of side edge sections defining a periphery of the case. One side edge section and an adjacent side edge section form a non-right angle therebetween such that the shaft can abut the side edge section, the first jaw can abut an adjacent side edge section, and the second jaw can abut another adjacent side edge section for calibrating or demonstrating the use of the caliper.

Abstract: A slide caliper includes an elongated shaft defining a gaging surface for abutting against a first surface of an object to be measured. A first jaw is coupled to the shaft and defines a gaging surface for abutting against a second surface of the object. A second jaw is slidably coupled to the shaft and defines a gaging surface for abutting against a third surface or edge of the object. The second jaw along the shaft is adjustable between a first position where the gaging surfaces of the jaws generally abut each other to a second position where the gaging surfaces of the jaws are maximally spaced from each other. At least one of the jaws is adjustably pivotable relative to the shaft about a pivot axis coinciding with an intersection of the gaging surface of the shaft and another axis extending along the associated gaging surface of the pivotable jaw.

Abstract: Strongly exothermic, catalytically induced or promoted chemical reactions, e.g. the production of methane by the reaction of hydrogen with carbon oxides, are carried out by passing the reactants through an isothermically operated reactor in addition to an adiabatic reactor.

Abstract: Highly exothermic continuous chemical reactions such as the methanization of carbon oxides are cooled by indirect heat exchange with a liquid coolant such as water, thereby converting at least some of the liquid to a vapor such as steam. When the reaction temperature, because of operational difficulties or the like, exceeds the design temperature of the reaction, said vapor such as steam is passed into the reaction chamber. In this way, the reaction stream is cooled as well as diluted; in addition, since the vapor is preferably selected to be a reaction product, the extent and rate of the exothermic reaction are diminished.

Abstract: In a process for the production of olefins in two stages wherein, in the first stage, heavy petroleum fractions are hydrogenated in the presence of hydrogen and a hydrogenation catalyst and, in the second stage, the thus-hydrogenated fractions are subjected to thermal cracking the presence of steam, the improvement which comprises employing as the hydrogenation catalyst a zeolite of the faujasite structure combined with elements from Groups VIB, VIIB and VIII of the periodic table of the elements, wherein the alkali component of the zeolite is exchanged at least partially for ammonium, hydronium, alkaline earth and/or rare earth ions, and the elements are present in a metallic, ionic, oxidic and/or sulfidic form.