Abstract: Hydrogenated boron-silicon alloy films having unexpected properties permitting in one embodiment the bonding together of metal and ceramic substrates by coating the surfaces to be bonded with the film mating the surfaces and heat treating the mated surfaces to expell hydrogen therefrom and to react to resulting boron-silicon alloy film with the substrates to form a liquid reaction product which forms a surface bond with the substrates or is at least partially absorbed in the substrates. In another embodiment, at least one surface of an intermetallic compound formed from elements selected from groups III and V of the periodic table is sealed against structural degradation by forming on the surface a solid boron-silicon-hydrogen alloy film. In still another embodiment, metal and organic resin substrates are protected against attack by water vapor, dissociated oxygen and molecular oxygen by forming a solid boron-silicon-hydrogen alloy film on the substrates.

Abstract: Hydrogenated boron-silicon alloy films having unexpected properties permitting in one embodiment the bonding together of metal and ceramic substrates by coating the surfaces to be bonded with the film mating the surfaces and heat treating the mated surfaces to expell hydrogen therefrom and to react to resulting boron-silicon alloy film with the substrates to form a liquid reaction product which forms a surface bond with the substrates or is at least partially absorbed in the substrates. In another embodiment, at least one surface of an intermetallic compound formed from elements selected from groups III and V of the periodic table is sealed against structural degradation by forming on the surface a solid boron-silicon-hydrogen alloy film. In still another embodiment, metal and organic resin substrates are protected against attack by water vapor, dissociated oxygen and molecular oxygen by forming a solid boron-silicon-hydrogen alloy film on the substrates.

Abstract: The present invention is directed to a vessel that is hull stabilized. The stability is achieved by the particular orientation of the lower hulls. In one embodiment the lower hulls are inclined to the calm water or design waterline.

Abstract: A method is described for selecting optical materials to use in designing color-corrected optical systems. Various dioptric, catadioptric and anamorphic optical systems are described, which use only two different types of optical materials to obtain precise axial color correction at three, four or five wavelengths (depending upon the particular optical materials), with only very small chromatic aberration occurring at wavelengths between the precisely color-corrected wavelengths. Examples of color-corrected lens systems comprising more than two glasses are also described.

Abstract: Mechanical stress applied to a crystal (10) by a procedure for forming a bond (13) between an electrical connector (12) and a metallized surface (11) of the crystal (10) is measured to obtain a quantitative indication of the quality of the bond (13). A beam of optical radiation generated by an illuminator (21) is divided by a first beamsplitter (22) into a first component and a second component. The power of the first component is measured by a first detector (23). The second component is circularly polarized by a circular polarizer (24), collimated by an imaging lens (25), and directed as an incident beam along an optical path through the crystal (10) to the metallized surface (11) in the vicinity of the bond (13). The metallized surface (11) reflects the incident beam back along the same optical path as a return beam.

Abstract: Hydrogenated boron-silicon alloy films having unexpected properties permitting in one embodiment the bonding together of metal and ceramic substrates by coating the surfaces to be bonded with the film mating the surfaces and heat treating the mated surfaces to expell hydrogen therefrom and to react to resulting boron-silicon alloy film with the substrates to form a liquid reaction product which forms a surface bond with the substrates or is at least partially absorbed in the substrates. In another embodiment, at least one surface of an intermetallic compound formed from elements selected from groups III and V of the periodic table is sealed against structural degradation by forming on the surface a solid boron-silicon-hydrogen alloy film. In still another embodimemt, metal amd organic resin substrates are protected against attack by water vapor, dissociated oxygen and molecular oxygen by forming a solid boron-silicon-hydrogen alloy film on the substrates.

Abstract: A catadioptric optical imaging system comprises a dioptric assembly (20) and a catoptric assembly (21), which are positioned with respect to each other to form an imaging system of long focal length. The dioptric assembly (20) comprises two confocal paraboloidal mirrors (22, 23) arranged to form a telescope of the Mersenne type. The catoptric assembly (21) comprises lens elements arranged in two groups, viz., a field group (25) and a relay group (26), which are coaxially disposed with respect to the dioptric assembly (20). Only two different optical materials, viz., calcium fluoride crystal and Hoya LAC7 glass, are used in making the lens elements of the dioptric assembly (20). The dioptric assembly (20) is color-corrected at five wavelengths and has only negligible secondary and higher-order spectra in a wavelength band extending from the ultraviolet region to the near infrared region of the optical spectrum.

Abstract: A method is described for selecting optical materials to use in designing color-corrected optical systems. Various dioptric, catadioptric and anamorphic optical systems are described, which use only two different types of optical materials to obtain precise axial color correction at three, four or five wavelengths (depending upon the particular optical materials), with only very small chromatic aberration occurring at wavelengths between the precisely color-corrected wavelengths. Examples of color-corrected lens systems comprising more than two glasses are also described.

Abstract: A method is described for selecting optical materials to use in designing color-corrected optical systems. Various dioptric, catadioptric and anamorphic optical systems are described, which use only two different types of optical materials to obtain precise axial color correction at three, four or five wavelengths (depending upon the particular optical materials), with only very small chromatic aberration occurring at wavelengths between the precisely color-corrected wavelengths. Examples of color-corrected lens systems comprising more than two glasses are also described.

Abstract: A probe (10) inductively couples radio-frequency electromagnetic energy into a test piece that is made of a multi-ply graphite-epoxy composite material whose fiber volume, ply count and/or thickness are to be measured. The probe (10) and the test piece form a system characterized by an electrical impedance vector, whose magnitude and phase are determined by the composition of the test piece. A frequency synthesizer (16) drives a compensating circuit (15), which applies the output of the frequency synthesizer (16) to the probe (10). The waveform and frequency of the frequency synthesizer (16) are selected to optimize the amount of energy coupled from the probe (10) into the test piece.

Abstract: A method is described for selecting optical materials to use in designing color-corrected optical systems. Various dioptric, catadioptric and anamorphic optical systems are described, which use only two different types of optical materials to obtain precise axial color correction at three, four or five wavelengths (depending upon the particular optical materials), with only very small chromatic aberration occurring at wavelengths between the precisely color-corrected wavelengths. Examples of color-corrected lens systems comprising more than two glasses are also described.

Abstract: An apparatus (10) for dispensing struts (11 and 12) for use by an astronaut in erecting a truss structure in extraterrestrial space comprises a frame to which a platform (16) is attached. The astronaut anchors himself to the platform (16) while erecting the truss structure. Pairs of retainer assemblies for securing opposite ends of struts of different lengths, i.e., the pair of retainer assemblies (22 and 23) for the struts (11), and the pair of retainer assemblies (22' and 23') for the struts (12), are also attached to the frame. One retainer assembly (22 or 22') from each pair is positioned within the astronaut's reach when he is anchored to the platform (16), and the other retainer assembly (23 or 23') from each pair is positioned remote from the astronaut's reach. Each of the remote retainer assemblies (23 and 23') comprises a plurality of spring-loaded receptacles (41) for receiving one end of the corresponding struts (11 or 12).

Abstract: A catadioptric optical imaging system comprises a dioptric assembly (20) and a catoptric assembly (21), which are positioned with respect to each other to form an imaging system of long focal length. The dioptric assembly (20) comprises two confocal paraboloidal mirrors (22, 23) arranged to form a telescope of the Mersenne type. The catoptric assembly (21) comprises lens elements arranged in two groups, viz., a field group (25) and a relay group (26), which are coaxially disposed with respect to the dioptric assembly (20). Only two different optical materials, viz., calcium fluoride crystal and Hoya LAC7 glass, are used in making the lens elements of the dioptric assembly (20). The dioptric assembly (20) is color-corrected at five wavelengths and has only negligible secondary and higher-order spectra in a wavelength band extending from the ultraviolet region to the near infrared region of the optical spectrum.

Abstract: In a liquid-propellant management system for providing substantially gas-free liquid propellant to thrusters of a space vehicle, a storage tank (10) has an opening (11) through which liquid propellant is delivered via a line (13) to the thrusters. A trap (14) is secured within the tank (10) adjacent the opening (11). and an exit port (15) of the trap (14) is aligned with the opening (11) of the tank (10). A liner (16) is secured inside the trap(14) to define a volume between an interior surface portion of the trap (14) and the liner (16), which volume communicates via the exit port (15) and the opening (11) with the line (13). Liquid propellant enters into the trap (14) through an inlet window screen (27), and passes through porous windows (28) in the liner (16) into the volume between the trap (14) and the liner (16). Vanes (19) are secured to the exterior surface of the trap (14) and extend into the interior of the tank (14) and the liner (16).

Abstract: A polarizing cube beamsplitter, which is designed for infrared applications, comprises two 45.degree. prisms made of ZnSe. A first anti-reflection layer, which is a Herpin equivalent layer consisting of the triad of sublayers ZnS-ZnSe-Zns, is deposited onto the hypotenuse of a first one of the prisms. Then, a polarizing stack consisting of a plurality of pairs of thin-film layers of alternating high and low refractive indices is formed on the first anti-reflection layer. One layer in each pair of thin-film layers in the polarizing stack is a Herpin equivalent layer consisting of the triad of sub-layers Te-ZnSe-Te, and the other layer in each pair is a thin film of ZnSe. A layer of prism material ZnSe, which is thick enough to be optically polished, is then formed on the second anti-reflection layer. The hypotenuse of the second prism is likewise optically polished, and is pressed onto the optically polished layer of prism material to form a bond. The resulting beamsplitter is of cubic configuration.

Abstract: A lens doublet comprising a positive lens element made of calcium fluoride crystal and a negative lens element made of Schott infrared transmitting glass IRGN6 enables an object to be imaged at four wavelengths in the visible region, or at four wavelengths in the near-infrared region, or at five wavelengths in a band extending from the visible to the near-infrared region of the electromagnetic spectrum. The doublet has practically negligible secondary and higher-order spectra throughout these spectral regions.

Abstract: An aircraft having a rotatively driven blade cooperating with an electrochemical power system for operating an electric drive system. The blade provides cooling heat transfer relative to the lithium/peroxide fuel system effecting desirable separation of the lithium-hydroxide monohydrate in a suitable filter/plenum provided as a portion of the power system. In one form, the cooling is effected by disposing a heat transfer portion of the power system in the path of air flow generated by the propulsion blade of the aircraft. In another form, the cooling is effected by flowing the electrolyte through the propulsion blade. Molarity of the electrolyte is maintained by separating the precipitated lithium-hydroxide monohydrate in solid form in the filter/plenum and addition of replacement hydrogen/peroxide solution from the reservoir thereof.

Abstract: A compact antenna for an extra-atmospheric vehicle is sufficiently rugged to withstand the rigors of atmospheric re-entry, and is capable of transmitting and receiving radio-frequency signals with selectable polarizations over a broad frequency bandwidth.

Abstract: A method is described for selecting optical materials to use in designing color-corrected optical systems. Various dioptric, catadioptric and anamorphic optical systems are described, which use only two different types of optical materials to obtain precise axial color correction at three, four or five wavelengths (depending upon the particular optical materials), with only very small chromatic aberration occurring at wavelengths between the precisely color-corrected wavelengths. Examples of color-corrected lens systems comprising more than two glasses are also described.

Abstract: Three different embodiments are shown of a photographic objective comprising only six lens elements, which is made of three different optical glasses, and which is well-corrected for both monochromatic and chromatic aberrations and has only negligible secondary and higher-order spectra in a wavelength band extending from the visible to the near infrared regions of the electromagnetic spectrum. The photographic objective is also color-corrected at four widely separated wavelengths in that band. The first embodiment is optimized for a 200 mm focal length at a relative aperture of f/4 over a 12.degree. field of view. The second embodiment is optimized for a 200 mm focal length at a relative aperture of f/5 over a 20.degree. field of view. The third embodiment is optimized for a 200 mm focal length at a relative aperture of f/4 over a 12.degree. field of view.