Abstract: A novolak resin suitable for use as a light-sensitive photoresist or maskant is prepared by reaction of at least one cresol with an aldehyde or reactive ketone and an aromatic hydroxyl compound having an alkyl side chain of from 3-15 carbon atoms. The addition of a conventional photosensitive agent yields a composition evidencing superior characteristics as compared with prior art novolak photoresists and which requires less sensitizer than such prior art resists.

Abstract: Superior top coatings for PVC are polyesters, especially a polyester blend of a terpolymer of tetramethylene glycol reacted with terephthalic acid, isophthalic acid, and azelaic acid, and a copolymer of ethylene glycol reacted with terephthalic acid and sebasic acid.

Abstract: The wasteful discharge of heated or cooled room air in a ventilating system to which a number of fume hoods are connected is reduced by making it possible to turn off unused hoods without unduly unbalancing the system and by making it possible, when access windows are closed, to reduce the volume of air flow to below the required open window level. Unconditioned outside air is automatically fed into the system in an amount compensating for the reduction in air available from the hoods when they are shut off or when flow from them is reduced. Switches are provided on the hood windows to change hood damper openings automatically to increase air flow when access windows are open and reduce it when windows are closed.

Abstract: Apparatus for winding a coil by feeding wire from a wire guide to a rotating bobbin and for terminating the coil by orbiting the wire guide about terminals projecting from the bobbin is made more versatile by mounting the wire guide so that it can be rotated from a position in which it feeds wire in a direction perpendicular to the bobbin axis to a position in which it feeds wire in a direction parallel to the bobbin axis. This construction permits termination of the coils upon terminals projecting from the bobbin in a direction parallel to the bobbin axis as well as those perpendicular to the bobbin axis. Introducing an offset portion to the spindle upon which the bobbin is rotated permits the wire guide to be brought into a position in which it can wrap a terminal projecting parallel to the coil axis on the inner or spindle side of the bobbin.

Abstract: Polycrystalline and amorphous semiconductors can be annealed using a laser or electron beam to restore or obtain crystal order by epitaxial regrowth on a crystal substrate. When the annealing occurs by liquid phase epitaxy, the presence and lifetime of a molten state at the region being annealed can be used to control the annealing process. Various control mechanisms are described.

Abstract: Damaged semiconductor materials are annealed using localized short term energy deposition. In a specific embodiment gallium arsenide damaged during ion implantation is annealed by exposure to short laser pulses.

Abstract: Optical fibers are produced with improved cross sectional circularity. In the course of the fabrication process, the tubular preform from which the fibers are drawn, is collapsed under positive internal pressure. This removes most cross sectional noncircularities that may have developed during fabrication of the preform, and also ensures the collapse of the preform to a structure with circular cross section.

Abstract: Microbending loss is reduced and abrasion protection is afforded for optical fibers by relatively thick polymer coatings characterized in part by a preferred elastic tensile modulus and cold flow property. The coating process uses rapid cooling of a liquid application to promote rapid gelation or solidification and thus achieve uniform coating diameter without beading. Fibers so coated are formed into ribbon structures having definite center-to-center fiber spacing. Preparation of coated fibers or ribbon structures for splicing is achieved by solvent stripping of the coating.

Abstract: A method of fabricating gallium arsenide MOS devices with improved stoichiometric and electrical properties is disclosed. The device includes a gallium arsenide substrate overlaid with a native oxide and an aluminum oxide layer. The device is fabricated using a plasma oxidizing process.

Abstract: An enclosed fume hood having an access window with a vertically sliding sash is provided with an additional horizontally movable sash which closes off only a fraction of the open window space and thus reduces the volume of air required to be drawn through the window in order to maintain the requisite air velocity while still permitting complete access to the interior of the hood. Provision is also made to permit the horizontally movable sash to be easily removed, when necessary, to permit insertion into the hood of apparatus wider than the residual open window space.

Abstract: Cu-Ni-Sn alloys are of commercial interest in applications which involve shaping by mechanical working of an alloy as well as in casting applications. Disclosed is a method which is particularly beneficial for casting and forging applications, i.e. applications which involve only limited amounts of working or none at all. The disclosed method allows the production of a fine-grained structure in a Cu-Ni-Sn alloy by a thermal treatment which calls for maintaining the alloy at three specified distinct temperature levels for specified time periods. The resulting fine-grained alloy may undergo further processing as may be beneficial, e.g., to develop desired levels of strength and ductility.

Abstract: Members of a class of garnet compositions of particular crystallographic orientation are usefully incorporated in magnetic memory devices which depend for their operation on the positioning of single wall domains ("bubbles"). Such compositions, ordinarily in the form of a supported layer defining a (110) orientation, manifest high limiting bubble velocity, thereby making possible high record and retrieval rates. Compositions invariably contain some lanthanum in the dodecahedral site. Increased limiting velocity is attributed to in-plane anisotropy, in turn, dependent upon partial lanthanum occupation. Depending upon composition, required unique easy direction out of the plane may be as-grown, stress induced, or a combination. Appropriate garnet substrates of required lattice parameters are described.

Abstract: A flame retardant, flexible, solder resistant covercoat has been formulated based on dichloropropyl acrylate.

Abstract: Cu-Ni-Sn alloys are disclosed which are particularly suited to undergo shaping by machining such as drilling, and lathing. In addition to Cu, Ni, and Sn, these alloys contain specified small amounts of Te, Se, Pb, or MnS. When articles are formed by machining of alloys having such specified composition, clogging of the machining tool and overheating of workpiece and machining tool are effectively prevented.

Abstract: An optical fiber is drawn from an appropriate preform using a laser whose output power is varied periodically at a rate greater than ten times a second. A fiber drawn in this manner has periodic variations in diameter which enhance the mode conversion properties of the fiber and thereby reduce the pulse dispersion of a signal transmitted through the waveguide.

Abstract: Liquid-semiconductor photocells using chalcogenide semiconductors have been advanced recently to the point where they compete favorably with silicon devices for solar power conversion. However, in common with silicon devices, the semiconductor needs to be a single crystal. This fact makes solar power impractically expensive. According to this invention, the chalcogenide semiconductor is made by anodizing cadmium or bismuth in a sulfide, selenide or telluride electrolyte. The anodized element, when operated photovoltaically in an electrolyte similar to the anodizing solution, produces useful power conversion and is relatively inexpensive.

Abstract: A device is disclosed which is capable of amplifying optical signals. The absorptive and dispersive properties of a cavity-enclosed nonlinear medium are combined with the transmission properties of the cavity to yield an input-output characteristic curve that displays gain or bistability.

Abstract: The operating frequency of an IMPATT diode depends on the width of the depletion region formed during operation. The frequency of high efficiency GaAs IMPATT diodes comprising a non-uniformly doped depletion region contacted by a rectifying barrier can be more precisely fixed by forming a "clump" of charge at exactly the depth below the surface contacted by the rectifying barrier corresponding to the desired depletion region.

Abstract: An improved reinforced flexible printed wiring board is disclosed. The reinforcement in this printed wiring board is composed of a fabric woven from a yarn of plied continuous filaments of polyester and glass. The fabric is impregnated with an appropriate resin which is subsequently cured. This printed wiring board is found to have improved mechanical and thermal characteristics with little degradation in electrical properties.

Abstract: A technique for monitoring the drawdown zone of an optical fiber preform is disclosed. The technique involves detecting the caustic rays emanating from the drawdown zone. Analysis of these rays allows one to determine the geometric properties of both the drawdown zone and the resultant optical fiber. In addition, detailed information concerning the index of refraction distribution in the fiber may be obtained. The process is amenable to realtime applications during the drawing of an optical fiber.