Abstract: Spatially-separated heterodyne interferometer architecture is combined with monolithic glass construction techniques to provide a monolithic, spatially-separated, common-path interferometer. The monolithic interferometer includes multiple optical components bonded together into a monolithic structure. The bonded components provide both optics and structure for the interferometer, thereby producing a small, compact, and light-weight interferometry system. Beam splitters and combiners are provided on the interfaces between the optical components to direct and combine signal measurement, signal reference and local oscillator beams used in the interferometry system. The spatially-separated architecture reduces cyclic error values below those of polarization-separated interferometers. In addition, the monolithic architecture of the interferometer minimizes the impact of mechanical, thermal, and optical variations within the system.

Abstract: Embodiments of the present invention are directed to a simple apparatus and a convenient and accurate method of mounting the components to form an off-axis reflective optical apparatus such as a collimator. In one embodiment, an off-axis reflective optical apparatus comprises a mounting block having a ferrule holder support surface and an off-axis reflector support surface which is generally perpendicular to the ferrule holder support surface. An optical reflector is mounted on the off-axis reflector support surface and has a reflected beam centerline. The optical reflector has a conic reflective surface and a conic center. A ferrule holder is mounted on the ferrule holder support surface. The ferrule holder provides a ferrule for coupling to an optical fiber and orienting a fiber tip of the optical fiber along a fiber axis toward the optical reflector. The fiber axis is nonparallel to the reflected beam centerline.

Abstract: A thermally compensating lens mount (40) comprises an axially symmetric housing (42) that is formed from an inner layer of a first material (44) having a low coefficient of thermal expansion (CTE) to an outer layer of a second material (46) having a high CTE. The longitudinal cross-section of the housing (42) has a barrel shaped geometry along the symmetry axis (47) so that differential thermal expansion of the first and second materials (44, 46) decreases the length of the housing (42) along its axis of symmetry (47) by an amount determined by the CTEs of the inner and outer layers (44, 46), their thicknesses, and the geometry of the barrel shape.

Abstract: In an optical system comprising a pair of rigid (e.g., glass) lens elements 11 and 12 mounted coaxially within a hollow cylindrical housing 10 so as to define a gap therebetween, a liquid (which functions as a liquid lens element 13) is contained within the gap. The rigid lens elements 11 and 12 are bonded to corresponding interior surface portions of the cylindrical housing 10 by means of an adhesive material that also functions as a sealant to prevent leakage of liquid from the gap. The adhesive sealant material preferably consists of a fluorosilicone sealant marketed by Dow Corning Corporation of Midland, Mich. under the trademark DOW CORNING X5-8738.

Abstract: In an optical system comprising a pair of rigid (e.g., glass) lens elements 11 and 12 mounted coaxially within a hollow cylindrical housing 10 so as to define a gap therebetween, a liquid (which functions as a liquid lens element 13) is contained within the gap. The rigid lens elements 11 and 12 are bonded to corresponding interior surface portions of the cylindrical housing 10 by means of an adhesive material that also functions as a sealant to prevent leakage of liquid from the gap. The adhesive sealant material preferably consists of a fluorosilicone sealant marketed by Dow Corning Corporation of Midland, Mich. under the trademark DOW CORNING X5-8738.

Abstract: A PTC heater assembly comprises at least one PTC heater surrounded by an envelope of high thermal conductivity, thus greatly increasing the power output of the heater under operating conditions. In a preferred assembly a strip heater, comprising (i) an elongate strip of a conductive polymer PTC composition, (ii) electrodes embedded in said strip, and (iii) an insulating jacket, is sandwiched between a pair of metal, e.g. aluminum, sheets.

Abstract: Apparatus for heating and filtering diesel fuel in which incoming diesel fuel is passed in a heat-exchange relationship with already heated and filtered diesel fuel, is further heated by either an electric heater or by other means, is passed through a filter, and then is passed in a regenerative heat-exchange relationship with the incoming diesel fuel.

Abstract: Apparatus and method for heating liquids, e.g. diesel fuel, by means of a conductive polymer heater which does not have an insulating jacket, so that there is direct physical contact between the liquid and electrically conductive parts of the heater. This results in improved heat transfer to the liquid. The unjacketed heater comprises a pair of elongate spaced electrodes embedded in an elongated strip of a conductive polymer, such as cross-linked polyvinylidene fluoride, which exhibits PTC behavior. The heater is positioned in a container through which diesel fuel to be heated flows from an entry port to an exit port. The exterior surface of the polymer strip is exposed and is directly contacted by the flowing diesel fuel.

Abstract: A PTC heater assembly comprises at least one PTC heater surrounded by an envelope of high thermal conductivity, thus greatly increasing the power output of the heater under operating conditions. In a preferred assembly a strip heater, comprising (i) an elongate strip of a conductive polymer PTC composition, (ii) electrodes embedded in said strip, and (iii) an insulating jacket, is sandwiched between a pair of metal, e.g. aluminum, sheets.

Abstract: A method for heating diesel prior to filtration by passing the diesel fuel through a heating apparatus including a container having entry and exit ports for the fuel and an elongated electrical heater arranged in spaced apart coils within the container for directing the flow of fuel so that, as the fuel flows from the entry port to the exit port, it flows along an elongate curved path which follows the coils of the heater and which curved path preferably has a length at least eight times the straightline distance between the entry and exit ports. The electric heater is unjacketed and comprises a pair of elongate electrodes embedded in an elongate strip of a conductive polymer composition which exhibits PTC behavior. The exterior surface of the elongate polymer strip is exposed so that it is directly contacted by the diesel fuel flowing through the container.

Abstract: A PTC heater assembly comprises at least one PTC heater surrounded by an envelope of high thermal conductivity, thus greatly increasing the power output of the heater under operating conditions. In a preferred assembly a strip heater, comprising (i) an elongate strip of a conductive polymer PTC composition, (ii) electrodes embedded in said strip, and (iii) an insulating jacket, is sandwiched between a pair of metal, e.g. aluminum, sheets.

Abstract: Nuclear fuel rods are manufactured utilizing a graphite flour-pitch matrix formulation containing an additive. The matrix formulation has a decreased viscosity at fabrication temperatures which permits manufacture of the fuel rods with lower fabrication pressures. Also, the matrix formulation does not cause the fuel rod to adhere or bond to the fuel element during heat treatment of the fuel rod in the fuel element. The nuclear fuel rods are suitable for use in high temperature gas cooled nuclear reactors.

Abstract: Nuclear fuel rods are manufactured utilizing a graphite flour-pitch matrix formulation containing an additive. The matrix formulation has a decreased viscosity at fabrication temperatures which permits manufacture of the fuel rods with lower fabrication pressures. Also, the matrix formulation does not cause the fuel rod to adhere or bond to the fuel element during heat treatment of the fuel rod in the fuel element. The nuclear fuel rods are suitable for use in high temperature gas cooled nuclear reactors.

Abstract: Particulate nuclear fuel material, particulate carbon and pitch are combined with an additive which is effective to reduce the coke yield upon carbonization to mold a green fuel body. The additive may be polystyrene, a styrene-butadiene copolymer, an aromatic hydrocarbon having a molecular weight between about 75 and 300 or a saturated hydrocarbon polymer. The green fuel body is inserted in a complementary cavity within a porous nuclear fuel element body and heated in situ to decompose the pitch and additive, leaving a relatively close-fitting fuel body in the cavity.

Abstract: Particulate graphite having a particle size not greater than about 1500 microns is impregnated with a polymerizeable organic compound in liquid form. The impregnated particles are treated with a hot aqueous acid solution to at least begin the polymerization reaction and remove excess impregnant from the outer surface thereof. The treated particles are heated to complete the polymerization and then blended with particulate nuclear fuel. A nuclear fuel body is formed by joining the blend into a cohesive mass using a carbonaceous binder.

Abstract: Apparatus is described for producing microspherical particles. Also described is a method for operating said apparatus. A droplet generator dispenses uniform spherical droplets into a gelling column which is sealed at both ends to prevent entry of air thereinto. A gelling liquid and a gelling gas are provided in the column, and a further gas, which is of a density lower than that of the gelling gas, is introduced to the region above the gelling gas. At the interface between the gelling gas and the further gas, the gases are withdrawn from the gelling column.