Abstract: This invention is directed to applying thermal barrier coating systems to hardware having passageways in the walls connecting apertures in the surface to a gas supply for film cooling. An inert gas, such as argon, is discharged through the apertures during the application of the thermal barrier coating system by plasma spraying. This flow of inert gas reduces both blocking of the holes and base metal oxidation during the coating operation.

Abstract: A laminated structural device has the ability to change shape, position and resonant frequency without using discrete motive components. The laminate (10) may be a combination of layers (14,16) of a piezoelectrically active, non-conductive matrix material as shown in FIG. 1. A power source (22) selectively places various levels of charge an electrically conductive filaments (18,20) imbedded in the respective layers to produce various configurations shown in FIGS. 2 to 5 in a predetermined manner. The layers may be electrically conductive having imbedded piezoelectrically active filaments. A combination of layers of electrically conductive material may be laminated to layers of piezoelectrically active material.

Abstract: An improved R.F. transmitting tube for the 20 GHz to 500 GHz range comprises a gyrotron (10) and a multistage depressed collector (11) as shown in FIG. 1. A winding (19) provides a magnetic field which acts on spent, spinning or orbiting electrons changing their motion to substantially forward linear motion in a downstream direction.The spent electrons then pass through a focusser (18) into the collector (11). Nearly all of the electrons injected into the collector will remain within an imaginary envelope designated by dashed lines 8 and 9 as they travel forward toward the end collector plate (26). The apertures in the collector plates (22-25) are at least as large in diameter as the envelope (8,9) at any particular axial position.FIG. 2 illustrates magnetic field strength from the cathode (13) of FIG. 1 to the collector entrance in focusser 18.

Abstract: This invention is concerned with an improved plating process for covering a substrate with a black metal oxide film. The invention is particularly directed to making a heating panel for a solar collector.A compound is electrodeposited from an aqueous solution containing cobalt metal salts onto a metal substrate. This compound is converted during plating into a black, highly absorbing oxide coating which contains hydrated oxides. This is achieved by the inclusion of an oxidizing agent in the plating bath.The inclusion of an oxidizing agent in the plating bath is contrary to standard electroplating practice. The hydrated oxides are converted to oxides by treatment in a hot bath, such as boiling water. An oxidizing agent may be added to the hot liquid treating bath.

Abstract: The method of the invention employs ferromagnetic or ferrimagnetic elements, preferably of rare-earth based material, for example gadolinium, and preferably employs a regenerator. The steps of the method comprise controlling the temperature and applied magnetic field of the element to cause the state of the element as represented on a temperature-magnetic entropy diagram repeatedly to traverse a loop. The loop may have a first portion of concurrent substantially isothermal or constant temperature and increasing applied magnetic field, a second portion of lowering temperature and constant applied magnetic field, a third portion of isothermal and decreasing applied magnetic field, and a fourth portion of increasing temperature and constant applied magnetic field. Other loops may be four-sided, with, for example, two isotherms and two adiabats (constant entropy portions).

Abstract: The object of the invention is to provide more effective film cooling to protect a wall surface from a hot fluid which impinges on or flows along the surface. A film of cooling fluid having increased area is provided by changing the direction of a stream of cooling fluid through an angle of from 135.degree. to 165.degree. before injecting it through the wall into the hot flowing gas.As shown in FIG. 1, cooling fluid is injected from an orifice (16) through a wall (10) into a hot flowing gas (11) at an angle (20) to form a cooling fluid film (12). Cooling fluid is supplied to the orifice (16) from a cooling fluid source (13) via a turbulence control passageway (14) having a curved portion (18) between two straight portions (17 and 19).The angle (24) through which the direction of the cooling fluid is turned results in less mixing of the cooling fluid with the hot gas (11), thereby substantially increasing the length of the film (12) in a downstream direction.FIGS.

Abstract: Zirconium carbide is used as a catalyst in a REDOX cell for the oxidation of chromous ions to chromic ions and for the reduction of chromic ions to chromous ions. The zirconium carbide is coated on an inert electronically conductive electrode which is present in the anode fluid of the cell.

Abstract: The ventricular catheter 10 of the present invention comprises a multiplicity of inlet microtubules 12. Each microtubule has both a large opening 16 at its inlet end and a multiplicity of microscopic openings 18 along its lateral surfaces.The microtubules are perforated by a new and novel ion beam sputter etch technique. The holes are etched in each microtubule by directing an ion beam 20 through an electro formed metal mesh mask 28 producing perforations having diameters ranging from about 14 microns to about 150 microns.This combination of a multiplicity of fluoropolymer microtubes, the numerous small holes provided in the lateral surfaces of the tubes, and the hydra-like distribution of the tubes provide a new and novel catheter. This structure assures a reliable means for shunting cerebrospinal fluid from the cerebral ventricles to selected areas of the body.

Abstract: This invention is directed to improving the thermal shock resistance of a ceramic layer. The invention is particularly directed to an improved abradable lining (16) that is deposited on a shroud (14) forming a gas-path seal in turbomachinery.Improved thermal shock resistance of a shroud is effected through the deliberate introduction of "benign" cracks. These are microcracks which will not propagate appreciably upon exposure to the thermal shock environment in which a turbine seal must function.Laser surface fusion treatment is used to introduce these microcracks. The ceramic surface is laser scanned to form a continuous dense layer as shown in FIG. 2. As this layer cools and solidifies, shrinkage results in the formation of a very fine crack network.The presence of this deliberately introduced fine crack network precludes the formation of a catastrophic crack during thermal shock exposure.

Abstract: A heat transparent high intensity solar cell has improved efficiency.A surface of each solar cell (10,16,22) has a plurality of grooves (12,14,18,20,24). Each groove has a vertical face (26,30) and a slanted face (28,32) that is covered by a reflecting metal (34,36).Light rays (38,40) are reflected from the slanted face through the vertical face where they traverse a photovoltaic junction (60). As the light rays travel to the slanted face of an adjacent groove, they again traverse the junction. The underside of the reflecting coating directs the light rays toward the opposite surface of solar cell as they traverse the junction again. When the light rays travel through the solar cell and reach the saw toothed grooves on the under side, the process of reflection and repeatedly traversing the junction again takes place. The light rays ultimately emerge from the solar cell as shown in FIG. 4.

Abstract: This invention is concerned with reducing the operating temperature and increasing the output of a solar cell.A solar cell (10) constructed in accordance with the invention carries electrodes (22) in a grid finger pattern on its back surface (12). These electrodes are sintered at the proper temperature to provide good ohmic contact.After sintering, a reflective material (24) is deposited on the back surface by vacuum evaporation. Thus, the application of the back surface reflector is separate from the back contact formation.Back surface reflectors formed in conjunction with separate grid finger configuration back contacts are more effective than those formed by full back metallization of the reflector material.

Abstract: This invention is directed to a method of joining the surfaces of two metal structures in a mechanical bond. The joining process can be performed in either art or vacuum. The metal surfaces of the structures 10 and 12 that are to be bonded are exposed to an ion beam 14 together with a target 18 of low sputtering yield material. This material deposits on the surfaces and creates sites of sputter resistance which evolve into peaks 20 of a cone like surface microstructure. The textured metal surfaces are arranged in face to face relationship and compressed together with plastic deformation which mechanically interlocks the cone 22. A large interface area is produced which minimizes thermal and electrical losses. Also, no electrical power or heat is required during metal joining.

Abstract: According to the invention a metal oxide coating is plated onto a metal substrate at the cathode from an acid solution which contains an oxidizing agent. The process is particularly useful for producing solar panels.Conventional plating at the cathode avoids the presence of oxidizing agents. Coatings made in accordance with the invention are stable both at high temperatures and while under the influence of high photon flux in the visible range.

Abstract: A specially textured surface of pyrolytic graphite exhibits extremely low yields of secondary electrons and reduced numbers of reflected primary electrons after impingement of high energy primary electrons.An ion flux having an energy between 500 eV and 1000 eV and a current density between 1.0 mA/cm.sup.2 and 6.0 mA/cm.sup.2 produces surface roughening or texturing which is in the form of needles or spines.Such textured surfaces are especially useful as anode collector plates in high efficiency electron tube devices.

Abstract: This invention is concerned with providing improved surface texturing for adhesive bonding, metal bonding, substrate plating, decal substrate preparation, and biomedical implant applications. The invention is particularly concerned with epoxy bonding to polymers that typically exhibit low adhesion and bonding metals to a desired thickness to a polymer substrate.The surface 12 to be bonded is first dusted in a controlled fashion to produce a disbursed layer of fine mesh particles 14 which serve as masks. The surface texture is produced by impinging gas ions on the masked surface. The textured surface takes the form of pillars or cones.The bonding material, such as a liquid epoxy, flows between the pillars which results in a bond having increased strength. For bonding metals a thin film of metal is vapor or sputter deposited onto the textured surface. Electroplating or electroless plating is then used to increase the metal thickness to the desired amount.

Abstract: A high voltage multijunction solar cell is provided wherein a plurality of discrete voltage generating regions or unit cells are formed in a single generally planar semiconductor body (12). The unit cells comprise a doped regions (20, 22) of opposite conductivity type separated by a gap or undiffused region (24). Metal contacts (26) connect adjacent cells together in series so that the output voltages of the individual cells are additive. In some embodiments, doped field regions (14) separated by gap (16) overlie the unit cells but the cells may be formed in both faces of the wafer (FIG. 2).

Abstract: NiCrAl alloys are improved by the addition of zirconium. These alloys are in the .beta. or .gamma./.gamma.'+.beta. region of the ternary system.Zirconium is added in a very low amount between 0.06 and 0.20 weight percent. There is a narrow optimum zirconium level at the low value of 0.13 weight percent.Maximum resistance to cyclic oxidation is achieved when the zirconium addition is at the optimum value.

Abstract: Clearance control means is provided for a gas turbine engine. In one embodiment relating to compressor blade clearance, means is provided for developing a first signal representative of the actual compressor casing temperature, a second signal representative of compressor inlet gas temperature, and a third signal representative of compressor speed. Schedule means is provided for receiving the gas temperature and compressor speed signals and developing a schedule output signal. The schedule output signal is representative of a reference casing temperature at which a predetermined compressor blade stabilized clearance is provided. Means is provided for comparing the actual compressor casing temperature signal and the reference casing temperature signal and developing a clearance control signal representative of the difference therebetween.

Abstract: This invention is concerned with improving adhesion, friction and wear properties of sputtered refractory coatings on substrates of materials that form stable nitrides.Each substrate (10) is placed directly below a titanium carbide target (16) of a commercial radiofrequency diode apparatus (14) in a vacuum chamber (26). Nitrogen is bled into the system through a nozzle (30) resulting in a small partial pressure of about 0.5% to 2.5% during the first two minutes of deposition. The flow of nitrogen is then stopped, and the sputtering ambient is reduced to pure argon through a nozzle (28) without interrupting the sputtering process.When nitrogen is deliberately introduced during the crucial interface formation, some of the titanium at the interface reacts to form titanium nitride while the metal of the substrate also forms the nitride. These two nitrides atomically mixed together in the interfacial region (38) act to more strongly bond the growing titanium carbide coating (12) as it forms on the substrate (10).

Abstract: This invention is concerned with a seal having a high temperature abradable lining material encircling the tips of turbine blades in turbomachinery. The invention is particularly directed to maintaining the minimum operating clearances between the blade tips and the lining of a high pressure turbine.A low temperature easily decomposable material, such as a polymer, in powder form is blended with a high temperature oxidation resistant metal powder. The two materials are simultaneously deposited on a substrate formed by the turbine casing. Alternately, the polymerpowder may be added to the metal powder during plasma spraying.A ceramic layer is then deposited directly onto the metal-polymer composite. The polymer additive mixed with the metal is then completely volatilized to provide a porous layer between the ceramic layer and the substrate.Thermal stresses are reduced by virtue of the resulting porous structure which affords a cushion effect.