Abstract: A continuous HCl in-air indicator consists of a tube-like element with an inlet end through which a continuous stream of air, containing HCl, enters. The air flows downstream from the inlet end and exits the element's outlet end. Positioned between the element's inlet and outlet ends are first and second spaced apart photoelectric units, which are preferably positioned adjacent the inlet and outlet ends, respectively. Ammonia gas is injected into the air, flowing through the element, at a position between the two photoelectric units. The ammonia gas reacts with the HCl in the air to form ammonium chloride particles. The difference between the outputs of the two photoelectric units is an indication of the amount of HCl in the air stream.

Abstract: Trap densities in dielectric films can be determined by tunnel injection measurements when the film is incorporated in an insulated-gate field-effect transistor (IGFET). Under applied bias to the transistor gate, carriers (electrons or holes) tunnel into traps in the dielectric film. The resulting space charge tends to change channel conductance. By feeding back a signal from the source contact to the gate electrode, channel conductance is held constant, and by recording the gate voltage as a function of time, trap density can be determined as a function of distance from the dielectric-semiconductor interface. The process is repeated with the gate bias voltage at different levels in order to determine the energy distribution of traps as a function of distance from the interface.

Abstract: A gear head wrench particularly suited for use in applying torque to bolts without transferring torsional stresses to bolt-receiving structures. The wrench is characterized by a coupling including a socket, for connecting a bolt head with a torque multiplying gear-train, provided within a housing having an annulus concentrically related to the socket and adapted to be coupled with a spacer interposed between the bolt head and the juxtaposed surface of the bolt-receiving structure for applying a balancing counter-torque to the spacer as torque is applied to the bolt head whereby the bolt-receiving structure is substantially isolated from torsional stress. As a result of the foregoing, the operator of the wrench is substantially isolated from any forces which may be imposed.

Abstract: An improved heat transfer device particularly suited for use as an evaporator plate in a diffusion cloud chamber. The device is characterized by a pair of mutually spaced heat transfer plates, each being of a planar configuration, having a pair of opposed surfaces defining therebetween a heat pipe chamber. Within the heat pipe chamber, in contiguous relation with the pair of opposed surfaces, there is disposed a pair of heat pipe wicks supported in a mutually spaced relationship by a foraminous spacer of a planar configuration. A wick including a foraminous layer is contiguously related to the external surfaces of the heat transfer plates for uniformly wetting these surfaces.

Abstract: An atmosphere sampler includes a very thin filter element with straight-through holes on the order of 1.mu.. A sample of air with particles to be examined is driven by means of a pressurized low molecular weight gas, e.g., He to the filter element front side. A partial vacuum may be present at the back side of the filter element. The pressure differential across the filter element is just below the rupture point of the filter element. By admixing a low molecular weight gas as the carrier gas with the air sampler the velocity with which the air sample is driven to the filter element is maximized for the particular pressure differential across the filter element, so that at least some particles with diameters less than the hole diameter do not follow changes in the air stream line direction as it passes through the filter element holes and therefore the smaller diameter particles are deposited on the filter element. When using a filter element of plastic material of a thickness on the order of 10.mu.

Abstract: For use in a waveguide gas laser a capillary tube of glass or ceramic has an inner surface defining a longitudinal capillary opening through which the laser gas flows. At least a portion of the inner surface is corrugated with corrugations or channels with a periodicity .LAMBDA. where .LAMBDA. = 1/2.lambda., .lambda. being the laser gas wavelength. The tube includes a diffused region extending outwardly from the opening. The diffused region of a depth d on the order of 1.lambda. to 3.lambda. acts as a waveguide for the waves, with the corrugations producing distributed feedback. The evanescent component of the waves travelling in the diffused region interact with the laser gas in the opening, gaining energy therefrom, and thereby amplifying the waves travelling in the diffused region, which exit the diffused region, surrounding the opening, as a beam of wavelength .lambda..

Abstract: Accurate, reproducible results in the tensile testing of thin metal foils are obtained by a method which comprises before placing the test specimen in a tensile testing machine, working the side edges of the test specimen until the edges are parallel and flaw-free, aligning the work specimen between spaced grip end members, securing end portions of the aligned test specimen to the grip end members, each of said grip end members containing female member means in face-to-face relationship to each other. The female member means are located on either side of and perpendicular to the plane of the test specimen and couple with corresponding male member means secured to the jaws of the tensile testing machine.An aligning apparatus employed in the method of the invention comprises an alignment box having a longitudinal bottom wall and two upright side walls, first and second removable grip end members disposed at each end of said box and means for securing the grip end members within the box.

Abstract: A miniature transducer for sensing muscle displacement substantially consists of a curved beam of high elastic compliance connected at its ends to two prongs. The prongs have sharpened tips which are insertable into the muscle under observation. A sensitive strain gauge is bonded to the beam preferably at the point of greatest curvature. The strain gauge output is directly related to changes in the beam curvature. As the muscle under observation expands the spacing between the prongs increases which decreases the beam curvature. On the other hand, when the muscle contracts the prongs' spacing decreases, thereby increasing the beam curvature.

Abstract: An analog-to-digital converter, finding particular application in a multichannel pulse height analyzer, includes means for digitizing the analog input in two conversion steps. To digitize the input to 13 bits, a 7-bit digital to analog converter (DAC) with a 7-bit up-down counter is used. During the first conversion step which is a coarse conversion, the input, V.sub.I, is compared with the DAC output, V.sub.L and the 7-bits of the counter are set by successive approximation. Thereafter, after settling, the DAC output is driven twice toward V.sub.I. The output of an amplifier of a gain 2.sup.7 is stored after each change of the DAC in one of two storage and hold circuits, depending on the polarity of the amplifier output. Then, the content of the 7-bit counter is transferred to the 7 higher order bits of a 14-bit buffer counter. Then, the fine conversion step is performed by successive approximation.

Abstract: A perforated tube is housed in a chamber in which vacuum is drawn. An air jet is directed into one end of the tube and fiber bundles are fed into the jet which separates and dispenses individual fibers from the bundle, fluffs them, cleanses them of any particulate material, and carries them into the tube. The tube retains the fibers while fiber fragments, undesirably short fibers and particulate matter are drawn by the vacuum and resultant air flow out of the tube through its perforations to a suitable discharge.

Abstract: A flask having a threaded neck and a cap adapted for threaded engagement on the neck. A laminated disc between the cap and the neck forms a gas tight seal and the cap has a central opening that exposes a medial region of the disc. Piercing the disc through the opening are two electrodes, the inner ends of which contact the sample within the flask and the outer ends of which afford connection of test equipment thereto. Cylindric glass tubes are fitted over the external portion of the electrodes to provide physical support therefor; silicone rubber or the like serves to retain the glass cylinders in place and form a gas tight seal between the cylinders and the electrodes. Shrinkable tubing is shrunk over the glass tubes to afford further mechanical support and sealing. A final relatively large diameter shrinkable tube is shrunk over both electrodes and their associated glass cylinders.

Abstract: A method of diffusion bonding and fluxless brazing of aluminum containing components, including a method of preparing aluminum containing surfaces for such welding techniques wherein the aluminum surfaces are freed of any aluminum oxide coating and are coated with a polymeric sealer which can be thermally removed leaving essentially no residue, the polymeric sealer being removed in a substantially oxygen-free environment and the aluminum components then being brazed or diffusion bonded without the use of a flux to remove oxide coating.

Abstract: Mass spectrometry apparatus for analyzing the composition of moving microscopic particles includes a capacitor having a front electrode upon which the particles impinge, a back electrode, and a solid dielectric sandwiched between the front and back electrodes. In one embodiment, the electrodes and dielectric are arcuately shaped as concentric peripheral segments of different spheres having a common center and different radii. The front electrode and dielectric together have a thickness such that an impinging particle can penetrate them. The front electrode is negatively biased relative to the back electrode so that an impinging particle causes the front and back electrodes to become electrically connected to form a discharge spark between the electrodes. The discharge spark causes ejection from the front electrode of positive ions of elements in the impinging particle. An electric field is formed in front of the front electrode by a grid that is pervious to the particles and ions.