Abstract: The present invention provides for measurements of the principal strain magnitudes and directions, and maximum shear strain that occurs in a porous specimen, such as plastic, ceramic or porous metal, when it is loaded (or subjected to a load). In one embodiment the invention includes a capacitive delta extensometer arranged with six sensors in a three piece configuration, with each sensor of each pair spaced apart from each other by a predetermined angle, such as 120 degrees.

Abstract: Volume measuring apparatus is used in a closed space as in the case of volume measurement of liquid in a container placed on an orbit of an artificial satellite and permits the volume measurement in a state without mixture with gas, liquid, or solid. A volume measuring apparatus is an apparatus for measuring the volume of liquid or solid under microgravity, which has two or more containers coupled to each other by a pipe, a device for separating or fixing a gas phase, a liquid phase, or a solid phase, a pressure fluctuation source, a pressure signal receiver, a pressure gage, and a thermometer, wherein the separating or fixing device, the pressure fluctuation source, the pressure signal receiver, the pressure gage, and the thermometer are placed in the containers and wherein the pressure fluctuation source, the pressure signal receiver, the pressure gage, and the thermometer are connected to a signal analyzing unit.

Abstract: A membrane structure includes an airtight pressure-resistant gasbag and a shape maintaining mechanism which maintains the gasbag in a predetermined shape when the gasbag is in a fully inflated state. The gasbag includes a plurality of spindle-shaped gores of an airtight membrane material, adjacent gores joined together at edges, and a plurality of reinforcing ropes attached to joined sections of the edges, the reinforcing ropes extending along the edges, respectively. Each of the gores outwardly protrudes between two adjacent reinforcing ropes extending along the edges of the gore, respectively, without elongation of the airtight membrane material, when the gasbag is in the fully inflated state. Each protruding gore has a radius of curvature in a direction intersecting the two adjacent reinforcing ropes. The radius of curvature is smaller than a radius of the gasbag.

Abstract: An optical device having a semi-spherical or hemispherical field-of-view is provided. A conically-shaped piece of optical material has an annular surface satisfying Snell's Law for total internal reflection with respect to light passing through the piece and incident on the annular surface from within the piece.

Abstract: A pair of substantially opposed mating surfaces are joined to each other and sealed in place by means of an electrically-conductive member which is placed in proximity to the mating surfaces. The electrically-conductive member has at least one element secured thereto which is positioned to contact the mating surfaces, and which softens when the electrically-conductive member is heated by passing an electric current therethrough. The softened element conforms to the mating surfaces, and upon cooling of the softened element the mating surfaces are joined together in an effective seal. Of particular significance is an embodiment of the electrically-conductive member which is a gasket having an electrically-conductive gasket base and a pair of the elements secured to opposite sides of the gasket base. This embodiment is positioned between the opposed mating surfaces to be joined to each other.

Abstract: An arcade race game having interchangeable components allowing for the formation of various games. The object of the game is to hit a target causing actuation of the race progression indication device. The first player to reach a predetermined point activates a detection device which stops the game and signals the winner of the game. The game structure is preferably pre-wired to accommodate various games. The processor may also be programmed to accommodate various game formats.

Abstract: Distributed approach for determining a path connecting adjacent network nodes, for probabilistically or deterministically transporting an entity, with entity characteristic &mgr; from a source node to a destination node. Each node i is directly connected to an arbitrary number J(&mgr;) of nodes, labeled or numbered j=j1, j2, . . . , jJ(&mgr;). In a deterministic version, a J(&mgr;)-component baseline proportion vector p(i;&mgr;) is associated with node i. A J(&mgr;)-component applied proportion vector p*(i;&mgr;) is determined from p(i;&mgr;) to preclude an entity visiting a node more than once.

Abstract: A multi-gas sensor is provided which modulates a polarized light beam over a broadband of wavelengths between two alternating orthogonal polarization components. The two orthogonal polarization components of the polarization modulated beam are directed along two distinct optical paths. At least one optical path contains one or more spectral discrimination elements, with each spectral discrimination element having spectral absorption features of one or more gases of interest being measured. The two optical paths then intersect, and one orthogonal component of the intersected components is transmitted and the other orthogonal component is reflected. The combined polarization modulated beam is partitioned into one or more smaller spectral regions of interest where one or more gases of interest has an absorption band.

Abstract: A system and method uses a wireless tether comprising a transmitter and a receiver to alert a caregiver that an object or person has been left unattended. A detector senses the presence of the object, usually a child, located in a position such as a safety seat. The detector couples to the transmitter, which is located near the object. The transmitter transmits at least one wireless signal when the object is in the position. The receiver, which is remotely located from the transmitter, senses the at least one signal as long as the receiver is within a prescribed range of transmission. By performing a timing function, the receiver monitors the proximity of the caregiver, who maintains possession of the receiver, to the transmitter. The system communicates an alarm to the caregiver when the caregiver ventures outside the range of transmission without having removed the object/child from the position.

Abstract: A system and method for RF autotracking multiple antennas (preferably located on a spacecraft) to compensate for disturbances experienced by the antennas. The system and method estimate high frequency errors associated with all of the antennas. The high frequency errors may be estimated using a currently selected antenna and a high-pass filter. The high frequency errors may be estimated using a sensor mounted on the spacecraft, such as a gyro or star tracker, or may be estimated using information, such as planned thruster firings, for example, from a spacecraft attitude control system. Alternatively, the high frequency information may be estimated using any combination of data from these sources. Low frequency errors are estimated using measurements from each selected antenna. The algorithm implemented in the present invention explicitly accounts for the frequency content of each disturbance source.

Abstract: A device is used for generating error signals for regulating the optical alignment of two lightwaves in connection with coherent heterodyne reception and comprises a receiver device (2, 3, 4) arranged focused opposite a front face at the end of a lightwave fiber (7) in order to make possible the transmission of the received information lightwave through the lightwave fiber (7) to an optical waveguide coupler (6), which is connected via a further lightwave fiber (13) with a local laser (12) and via two further lightwave fibers (8, 9) with respectively one detector (10, 11) for generating at least one error signal (Sr). A piezoelectric deflection unit (5) acts on this front face of the lightwave fiber (7) located in the focusing area of the receiving device.

Abstract: Polymer encapsulated metal oxide particles are prepared by combining a polyamide acid in a polar aprotic solvent with a metal alkoxide solution. The polymer was imidized and the metal oxide formed simultaneously in a refluxing organic solvent. The resulting polymer-metal oxide is an intimately mixed commingled blend, possessing synergistic properties of both the polymer and preceramic metal oxide. The encapsulated metal oxide particles have multiple uses including, being useful in the production of skin lubricating creams, weather resistant paints, as a filler for paper, making ultraviolet light stable filled printing ink, being extruded into fibers or ribbons, and coatings for fibers used in the production of composite structural panels.

Abstract: An apparatus and method for measuring strain of gratings written into an optical fiber. Optical radiation is transmitted over one or more contiguous predetermined wavelength ranges into a reference optical fiber network and an optical fiber network under test to produce a plurality of reference interference fringes and measurement interference fringes, respectively. The reference and measurement fringes are detected, and the reference fringes trigger the sampling of the measurement fringes. This results in the measurement fringes being sampled at 2&pgr; increments of the reference fringes. Each sampled measurement fringe of each wavelength sweep is transformed into a spatial domain waveform. The spatial domain waveforms are summed to form a summation spatial domain waveform that is used to determine location of each grating with respect to a reference reflector.

Abstract: An apparatus for measuring high frequency currents includes a non-ferrous core current probe that is coupled to a wide-band transimpedance amplifier. The current probe has a secondary winding with a winding resistance that is substantially smaller than the reactance of the winding. The sensitivity of the current probe is substantially flat over a wide band of frequencies. The apparatus is particularly useful for measuring exposure of humans to radio frequency currents.

Abstract: A propulsion system for a spacecraft includes a solar sail system and an electrodynamic tether system. The solar sail system is used to generate propulsion to propel the spacecraft through space using solar photons and the electrodynamic tether system is used to generate propulsion to steer the spacecraft into orbit and to perform orbital maneuvers around a planet using the planet's magnetic field. The electrodynamic tether system can also be used to generate power for the spacecraft using the planet's magnetic field.

Abstract: A patch filter element has an electrically-insulating substrate with an electrically conductive region on a first surface of said substrate, and a slot such as a crossed slot dividing the conductive region into a plurality of triangular sections. A mode coupling device, such as a cutout corner of a triangular section, induces orthogonal modes of vibration of an electromagnetic field about the plurality of sections. The ferroelectric oxide is disposed in the slot for adjusting a dielectric constant of the oxide in accordance with a bias voltage applied across the slot between adjacent ones of the sections for turning the patch filter element. Metallic walls may be constructed along edges of the slot for increased capacitance.

Abstract: A measuring device for providing data corresponding to a geometric configuration in space, in the form of a flexible, compliant, measurement member capable of bending in at least one degree of freedom and extending along a medial axis or plane. The member has spaced flexure sensors distributed at known locations on the member and separated by known sensor spacing intervals to provide flexure signals indicating the local state of flexure present at the locations. The member comprises a multiplicity of formed, i.e. shaped, fibers, these fibers including sensing fibers having sensing portions which provide the flexure sensors, the sensing portions of different fibers being located at differing distances along the member so as to be located at the sensor spacing intervals, the formed fibers being in mutually supporting relationship, as by continuous or repeated contact with each other. Such fibers may constitute most or all of the member.

Abstract: A distance tracking control system, for use with a working member such as a robotic head, includes a non-contact distance sensor for sensing a distance of the working member from a surface. An actuator is provided for making positional adjustments of the working member in response to changes in the distance sensed by the non-contact distance sensor. A controller is connected to the distance sensor and the actuator. The controller receives data from the non-contact distance sensor and then sends signals to the actuator to make positional adjustments of the working member.

Abstract: In addition to height data for objects being calculated from stereographic pair images photographed from a satellite, information on outlines is also extracted, and by integrating this height data with the stereographic pair images a three-dimensional database is generated including buildings or else using realistic texture.

Abstract: An optical unit (10) comprising a plurality of optical elements, a receiving structure (12) with a plurality of element supports (40, 41) for receiving the optical elements. The element supports (40, 41) are in the form of a plate or shell or tube, whose dimensions are greater than the dimensions of the optical elements to be received, and is connected to another element support. At least one element support (40, 41) comprises temperature elements (43-49) that can be heated and/or cooled. The optical unit (10) furthermore comprises a control unit for driving the temperature elements (43-49) in order to locally change the temperature of the at least one element support (40, 41) so as to influence in a controlled manner the shape of the at least one element support (40, 41).