Abstract: A smooth, oblique-angled endface fracture of an optical fiber 39 useful in low reflectance, low insertion loss mechanical splices is achieved by creating tensile stress in the fiber and scoring the fiber at an angle to its longitudinal axis. Tension may be applied by bending the fiber with a flexible platen 16 to which it is affixed, and the scoring may be accomplished by scribing the fiber surface with a sharp point or impressing a notch into the fiber with a blade 28.

Abstract: Methods are described for the low temperature preparation of the spinel LiMn.sub.2 O.sub.4 and layered LiCoO.sub.2 phases which are intercalable compounds of interest for use in lithium secondary batteries. These phases can be prepared in bulk or thick film form at temperatures less than 400.degree. C. using acetate precursors.

Abstract: A technique for the preparation of an oriented thin film polydiacetylene suitable for use in channel waveguides involves depositing an alignment polymer upon a substrate, rubbing the surface thereof to effect orientation, depositing the polydiacetylene thereon and heating to a temperature just below the melting point thereof.

Abstract: A lithium metal free non-aqueous secondary battery including a carbon anode and a lithium manganese oxide cathode is described. In operation, lithium from the lithium manganese oxide positive electrode intercalates with the carbon negative electrode and in this manner lithium ions are rocked back and forth during charge-discharge cycling. Lithium manganese oxide of the formula Li.sub.2 Mn.sub.2 O.sub.4 may also be used as the cathode and this material may be prepared by a novel technique which involves reacting LiMn.sub.2 O.sub.4 with lithium iodide at low temperatures (150.degree. C.), or alternatively by refluxing LiMn.sub.2 O.sub.4 in an acetonitrile solution of lithium iodide.

Abstract: A film of linear organosilsesquioxane polymer, or "ladder" organosiloxane, coated upon the surface of a LiMn.sub.2 O.sub.4 secondary battery electrode 19 and cured to a glassy layer is subjected to plasma oxidation to remove pendant organic groups comprising the coated polymer. The resulting ultrathin silica separator layer 17 is replete with minute pores which take up and retain by capillarity a typical LiClO.sub.4 electrolyte solution. A counter-electrode 15 placed in intimate contact with the silica electrolyte element completes a secondary battery structure 10 in which lithium ions readily migrate through the electrolyte during repeated discharge/charge cycles without loss of element integrity or efficacy.

Abstract: An electrolyte resistant to oxidation normally resulting from high voltage charging of a secondary battery comprising a Li.sub.1+x Mn.sub.2 O.sub.4 intercalation positive electrode comprises a 0.5M to 2M solution of LiPF.sub.6 dissolved in a mixture of non-aqeuous dimethylcarbonate (DMC) and ethylene carbonate (EC) solvents wherein said solvents are present in a weight percent ratio range from about 95 DMC:5 EC to 20 DMC:80 EC.

Abstract: A non-volatile memory element based upon a thin epitaxial film of manganese aluminum upon a III-V semiconductor is described. The film is stable at elevated temperatures required for III-V semiconductor device processing, so permitting the monolithic integration of non-volatile memory elements with III-V semiconductor electronic and photonic devices.

Abstract: A system for time-stamping a digital document, for example any alphanumeric, video, audio, or pictorial data, protects the secrecy of the document text and provides a tamper-proof time seal establishing an author's claim to the temporal existence of the document. Initially, the document may be condensed to a single number by means of a one-way hash function, thereby fixing a unique representation of the document text. The document representation is transmitted to an outside agency where the current time is added to form a receipt. The agency then certifies the receipt by adding and hashing the receipt data with the current record catenate certificate which itself is a number obtained as a result of the sequential hashing of each prior receipt with the extant catenate certificate. The certified receipt bearing the time data and the catenate certificate number is then returned to the author as evidence of the document's existence.

Abstract: Method is described for the low temperature preparation of the spinel LiMn.sub.2 O.sub.4 phase which is an intercalable compound of interest for use in lithium secondary batteries. This phase can be prepared in bulk or thick film form at temperatures less than 400.degree. C. using acetate precursors.

Abstract: A system for time-stamping a digital document, including for example text, video, audio, or pictorial data, protects the secrecy of the document text and provides a tamper-proof time seal establishing an author's claim to the temporal existence of the document. Initially, the author reduces the document to a number by means of a one-way hash function, thereby fixing a unique representation of the document text. In one embodiment of the invention the number is then transmitted to an outside agency where the current time is added to form a receipt which is certified by the agency using a public key signature procedure before being returned to the author as evidence of the document's existence. In later proof of such existence, the certificate is authenticated by means of the agency's public key to reveal the receipt which comprises the hash of the alleged document along with the time seal that only the agency could have signed into the certificate.

Abstract: A smooth, oblique-angled endface fracture of an optical fiber 20 useful in low reflectance, low insertion loss mechanical splices is achieved by tensioning the fiber while it is in contact with the abrupt edge 23 of an anvil 22 and applying a shearing force to the fiber at a point closely offset from the anvil edge and in a direction substantially perpendicular to the longitudinal axis of the fiber.

Abstract: A Thin film electrode for a rechargeable (secondary) battery is prepared by electron beam deposition of LiMn.sub.2 O.sub.4, LiCoO.sub.2, or LiNiO.sub.2 on a smooth, amorphous substrate surface and in situ annealing of the deposited lithium composition at a temperature below about 500.degree. C. The amorphous nature of the substrate surface prevents epitaxial growth or ordered orientation of the minute composition crystallites thus formed. The finely granular structure of the resulting electrode thin film presents abundant surface area that enables a 4V battery to provide current densities in the range of 500 microamps/cm.sup.2. The low annealing temperature enables formation of the electrode structure and subsequent battery assembly directly upon semiconductor devices and integrated circuitry.

Abstract: A rheological device suitable for measuring the rate of polymerization of ultraviolet sensitive polymers includes a part of open-ended cylindrical fixtures having removable quartz windows at one end. The upper fixture is adapted with a window which permits light to enter and impinge upon the surface of an elliptically-shaped mirror. Curing is monitored by measuring the elastic and viscous moduli during polymerization.

Abstract: In a solid-electrolyte fuel cell of the type described in U.S. Pat. No. 4,863,813 a permeable catalytic electrode in contact with the solid electrolyte is ordinarily exposed to a mixture comprising an oxidizer and a hydrogen-containing fuel. To increase the fuel efficiency of the cell, the permeable electrode is patterned and coated with a material that is permeable to the fuel but relatively impermeable to the oxidizer. The oxidizer enters the electrolyte through channels where the surface of the electrolyte is not covered by the patterned and coated electrode.

Abstract: A method for the passivation of superconductive rare earth cuprates involves depositing thereon a thin film of an amorphous or diamond-like carbon film of a thickness ranging from 100 .ANG. to 10 microns. The cuprate film may be in the as-deposited form, so necessitating a subsequent annealing step to convert the film to a superconducting phase and to remove the carbon.

Abstract: A class of intermetallic compound contact materials for III-V semiconductors is obtained by depositing successively and concurrently a thin film of a transition metal and a Group III metal upon the semiconductor and annealing the resultant structure, so resulting in the formation of a monocrystalline intermetallic contact. The contacts are stable at temperatures ranging from 600.degree.-900.degree. C. and may be fabricated by conventional vacuum deposition.

Abstract: A reactive gas detection system provides early warning of gas emissions that often occur in developing fire conditions in environments such as telephone system central offices where halogenated substances, for example polyvinyl chloride wire insulation and brominated fire retardant materials, are prevalent. Multiple microbalance detectors (122) comprising quartz crystal oscillators coated with a layer of zinc or zinc compound are distributed about a premises and the rate of change of crystal oscillation frequency is cyclically monitored by a frequency counter (130) under control of a data processor (112). The detectors are specifically reactive to the halogen acid gases emitted during pyrolysis of the noted substances and exhibit a significant differential frequency change in the presence one or more of these gases well in advance of the outbreak of flame, smoke, or other normally detectable combustion products.

Abstract: Rapid restoration of a telecommunication path between network nodes after an interrupting network link failure utilizes a distributed system of selective flooding for dynamically reconfiguring the internodal path in a manner which will ensure the most economical use of intermediate links. A help message transmitted from one of the terminating nodes to each contiguous neighboring node requests use of the uncommitted bandwidth of each respective link. This wave of messages is propagated selectively, along paths having maximum available bandwidth and least number of links, through the network by each successive receiving node until the help message reaches the other terminating node of the failed link. An acknowledgement message returned to the initial terminating node via propagation links offering the maximum bandwidth establishes a reconfigured path providing the greatest bandwidth recovery.

Abstract: A class of intermetallic compound contact materials for III-V semiconductors is obtained by depositing successively and concurrently a thin film of a transition metal and a Group III metal upon the semiconductor and annealing the resultant structure, so resulting in the formation of a monocrystalline intermetallic contact. The contacts are stable at temperatures ranging from 600-900.degree. C. and may be fabricated by conventional vacuum deposition.

Abstract: A solid electrolyte fuel cell capable of operating with a mixture of an oxidizer and a fuel includes a permeable catalytic electrode and an impermeable catalytic electrode separated by an electron insulating, ion conducting, gas permeable solid electrolyte. The device produces charge flow in an external circuit when the permeable electrode is exposed to a mixture including an oxidizer and a fuel such as hydrogen, methane or methanol.The solid electrolyte can be a hydrated aluminum oxide, primarily of the pseudoboehmite structure and either electrode can be Pt or Pd. The solid electrolyte can be produced by exposing a bulk aluminum surface or a deposited layer of aluminum to water or water vapor or by exposing an anodically oxidized layer of aluminum oxide to water or water vapor. The device is produced in thin film form and can be produced by techniques compatible with thin film device fabrication.