Abstract: An etching process for patterning cermet thin film resistors includes the provision of a layer of molybdenum over the cermet layer to provide a good adherent surface for a photoresist layer subsequently deposited thereon. After the photoresist and molybdenum layers are patterned in separate steps, the cermet is preferentially etched with hot phosphoric acid to produce the desired cermet resistance pattern.

Abstract: A work part resting on a work support is clamped to the work support by means of a self-aligning work holding clamp having a pair of clamp members which are pivotally mounted and operated by actuating means acting between the members in such a way that the members automatically align themselves with the work part during closure of their jaws against the part to effect clamping of the part to the support without exerting on the part a force tending to move the part relative to the support in the direction of jaw movement. The clamp jaws may be spring biased to open position and to a predetermined position relative to the support.

Abstract: A wire mesh structure, primarily for space applications, characterized by its lightweight, its compact stowage and deployment capability, and its ability to maintain its shape under widely varying thermal conditions. The structure has a frame supporting a wire mesh including wires which are terminally secured to the frame and constitute the primary structural elements of the mesh. These structural wires are preformed to a spring-like configuration which renders the wires resiliently compliant with a low spring rate in the endwise direction and are stretched to produce a predetermined tension preload in the wires when the mesh is installed on the supporting frame. This preload retains the mesh in a taut condition under widely varying thermal conditions and thereby prevents the formation of slack in the mesh which would allow out-of-plane displacement of the mesh.

Abstract: A work part is compared to a master part, to measure the deviation, if any, between the parts, using a comparison gaging instrument having a master gaging probe with a fixed master engaging tip and a work gaging probe with an axially floating work engaging tip.

Abstract: Coal is catalytically reacted with steam to produce hydrogen. Various Group I metal salts such as K.sub.2 CO.sub.3, Na.sub.2 CO.sub.3 and borax are used as catalysts. These catalysts are stabilized with fluoride containing salts such as CaF.sub.2 to thereby extend their life. Alternatively, NaF was found to be a thermally stable catalyst for the reaction.

Abstract: A process for the in-situ recovery of hydrocarbon, carbon monoxide, and hydrogen values and associated minerals from subsurface oil shale deposits is provided by forming a gas-tight retort chamber and injecting it with a hot, pressurized gas followed by a solvent extraction and finally a combustion of the hydrocarbon residue. In order to conduct the process, the shale formation must be beneath a gas impermeable geological structure which will form a gas-tight chamber upon leaching of the water soluble minerals.

Abstract: A redundancy switching system particularly suitable for transponders of the type used in spacecraft. A plurality of elements such as amplifiers is selectively connectable to a similar plurality of terminals such as input or output ports by switches. For each amplifier there is provided one switch and the switches are interconnected to form a closed loop. The switches may have three or four-port configuration and may be double-pole or triple-pole transfer switches, wafer switches, waveguide transfer switches or the like. In another form of the invention each element is connected to one output port by a switch and additional redundant elements are cross-connected to each other by extra switches so that failed elements can be replaced by standby elements.

Abstract: A process for the in-situ recovery of hydrocarbon, carbon monoxide, and hydrogen values and associated minerals from subsurface oil shale deposits is provided by forming a gas-tight retort chamber and injecting it with various process gases which are pressure cycled over a predetermined period of time. This pressure cycling increases the extraction efficiency by improving the recovery of material contained in blind cracks in the underground formation, and by provising an independent means of controlling the thermal gradients induced in the deposit.

Abstract: An impulser for percussively loading a structure to generate stress waves in the structure by driving a hammer into impact relation with the structure and generating an electrical signal in timed relation to the impact. The impulser may embody means, such as suction cups, for firmly attaching the impulser to the structure and an anvil which is interposed between the hammer and structure and spring loaded against the structure for transmitting the hammer impact to the structure without damaging the structure.