Abstract: A method and apparatus are provided which are especially useful for leak testing seams such as an end closure or joint in an article. The test does not require an enclosed pressurized volume within the article or joint section to be leak checked. A flexible impervious membrane is disposed over an area of the seamed surfaces to be leak checked and sealed around the outer edges. A preselected vacuum is applied through an opening in the membrane to evacuate the area between the membrane and the surface being leak checked to essentially collapse the membrane to conform to the article surface or joined adjacent surfaces. A pressure differential is concentrated at the seam bounded by the membrane and only the seam experiences a pressure differential as air or helium molecules are drawn into the vacuum system through a leak in the seam. A helium detector may be placed in a vacuum exhaust line from the membrane to detect the helium.

Abstract: Oxide compositions containing niobium pentoxide and an oxide selected from the group consisting of hafnia, titania, and zirconia have electrical conductivity characteristics which vary greatly depending on the oxygen content.

Abstract: Graphite is joined to graphite by employing both fine molybdenum powder as the brazing material and an annealing step that together produce a virtually metal-free joint exhibiting properties similar to those found in the parent graphite. Molybdenum powder is placed between the faying surfaces of two graphite parts and melted to form molybdenum carbide. The joint area is thereafter subjected to an annealing operation which diffuses the carbide away from the joint and into the graphite parts. Graphite dissolved by the dispersed molybdenum carbide precipitates into the joint area, replacing the molybdenum carbide to provide a joint of virtually graphite.

Abstract: 1.

Abstract: An improved method for treating metal-loaded resin microspheres is described which comprises heating a metal-loaded resin charge in an inert atmosphere at a pre-carbide-forming temperature under such conditions as to produce a microsphere composition having sufficient carbon as to create a substantially continuous carbon matrix and a metal-carbide or an oxide-carbide mixture as a dispersed phase(s) during carbide-forming conditions, and then heating the thus treated charge to a carbide-forming temperature.

Abstract: A remotely operable sampler is provided for obtaining variable percentage samples of nuclear fuel particles and the like for analyses. The sampler has a rotating cup for a sample collection chamber designed so that the effective size of the sample inlet opening to the cup varies with rotational speed. Samples of a desired size are withdrawn from a flowing stream of particles without a deterrent to the flow of remaining particles.

Abstract: This invention is an improved electronic alarm relay for monitoring the current drawn by an AC motor or other electrical load. The circuit is designed to measure the load with high accuracy and to have excellent alarm repeatability. Chattering and arcing of the relay contacts are minimal. The operator can adjust the set point easily and can re-set both the high and the low alarm points by means of one simple adjustment. The relay includes means for generating a signal voltage proportional to the motor current. In a preferred form of the invention a first operational amplifier is provided to generate a first constant reference voltage which is higher than a preselected value of the signal voltage. A second operational amplifier is provided to generate a second constant reference voltage which is lower than the aforementioned preselected value of the signal voltage.

Abstract: An electrical connector is provided for coupling high current capacity electrical conductors such as copper busses or the like. The connector is arranged in a "sandwiched" configuration in which a conductor plate contacts the busses along major surfaces thereof clamped between two stainless steel backing plates. The conductor plate is provided with a plurality of contact buttons affixed therein in a spaced array such that the caps of the buttons extend above the conductor plate surface to contact the busses. When clamping bolts provided through openings in the sandwiched arrangement are tightened, Belleville springs provided under the rim of each button cap are compressed and resiliently force the caps into contact with the busses' contacting surfaces to maintain a predetermined electrical contact area provided by the button cap tops. The contact area does not change with changing thermal or mechanical stresses applied to the coupled conductors.