Abstract: A delay circuit includes a first network having an input and an output node, a second network having an input and an output, the input of the second network being coupled to the output node of the first network. The first network and the second network are configured such that: a glitch at the input to the first network having a length of approximately one-half of a standard glitch time or less does not cause the voltage at the output of the second network to cross a threshold, a glitch at the input to the first network having a length of between approximately one-half and two standard glitch times causes the voltage at the output of the second network to cross the threshold for less than the length of the glitch, and a glitch at the input to the first network having a length of greater than approximately two standard glitch times causes the voltage at the output of the second network to cross the threshold for approximately the time of the glitch.

Abstract: A Digital Video Quality (DVQ) apparatus and method that incorporate a model of human visual sensitivity to predict the visibility of artifacts. The DVQ method and apparatus are used for the evaluation of the visual quality of processed digital video sequences and for adaptively controlling the bit rate of the processed digital video sequences without compromising the visual quality. The DVQ apparatus minimizes the required amount of memory and computation. The input to the DVQ apparatus is a pair of color image sequences: an original (R) non-compressed sequence, and a processed (T) sequence. Both sequences (R) and (T) are sampled, cropped, and subjected to color transformations. The sequences are then subjected to blocking and discrete cosine transformation, and the results are transformed to local contrast. The next step is a time filtering operation which implements the human sensitivity to different time frequencies.

Abstract: When a crystalline nucleus generated from an under-cooled silicon droplet is grown up to a mono-crystalline silicon ball, a critical under-cooling &Dgr;Tcr is determined in response to a diameter d of the silicon droplet so as to satisfy the relationships of (d=5 mm, &Dgr;Tcr=100K), (d=3 mm, &Dgr;Tcr=120K) and (d=1 mm, &Dgr;Tcr=150K). A crystal grown up from the crystalline nucleus at an under-cooling &Dgr;T less than the critical under-cooling &Dgr;Tcr is a mono-crystalline silicon ball with high quality free from cracks or twins.

Abstract: A multi-purpose thermal insulation test apparatus is used for testing insulation materials, or other components. The test apparatus is a fluid boil-off calorimeter system for calibrated measurement of the apparent thermal conductivity (k-value) of a specimen material at a fixed vacuum level. The apparatus includes an inner vessel for receiving a fluid with a normal boiling point below ambient temperature, such as liquid nitrogen, enclosed within a vacuum chamber. A cold mass assembly, including the inner vessel and thermal guards, is suspended from the top of the vacuum chamber. Handling tools attach to the cold mass assembly for convenient manipulation of the assembly and for the installation or wrapping of insulation test materials. Liquid nitrogen is typically supplied to the inner vessel using a fill tube with funnel. A single port through the top of the vacuum chamber facilitates both filling and venting.

Abstract: A method is disclosed for growing high-quality low-defect crystal films heteroepitaxially on substrates that are different than the crystal films. The growth of the first two heteroepitaxial bilayers is performed on a first two-dimensional nucleate island before a second growth of two-dimensional nucleation is allowed to start. The method is particularly suited for the growth of 3C-SiC, 2H-AlN, or 2H-GaN on 6H-SiC, 4H-SiC, or silicon substrates.

Abstract: Electronic system for generating and controlling light effects on projectors utilizing arc lamps, composed of an electronic power unit provided with a transformer fed via transistors, the secondary circuit of the transformer being connected to the feed terminals of the lamp, within the secondary circuit of the transformer there being connected a component for withdrawing a proportion of the instantaneous current circulating through the secondary circuit to produce an electrical signal which is made available to a control block which also receives an electrical reference signal generated by a pulse generator, the control block being arranged to compare the two electrical signals and to set the transistors to a conducting or inhibiting state depending on the result of the comparison, the amplitude and frequency of the electrical reference signal being adjustable by the operator.

Abstract: The polyesters of this invention are derived from a Diels-Alder cyclopolymerization of a photochemically generated bisdiene with dienophiles, such as di(acrylates), tri(acrylates), di(methacrylates), tri(methacrylates) and mixtures thereof with mono(methacrylates) or mono(acrylate) end-caps. Irradiation of one or more diketones produces two distinct hydroxy o-quinodimethane (photoenol) intermediates. These intermediates are trapped via a Diels-Alder cycloaddition with appropriate dienophiles, e.g., di(acrylates) to give the corresponding in polyesters quantitative yields. When di(acrylates), tri(acrylates) and di and tri(methacrylates) or mixtures thereof with monoacrylate end-caps are used as the dienophile, the resulting polyesters have glass transition temperatures (Tg) as high as 200° C. Polyesters films can be prepared by ultraviolet irradiation of high solids content varnishes of the monomers in a small amount of solvent, e.g., cyclohexanone, dimethyl formamide, N-methylpyrollidone and the like.

Abstract: The present invention provides systems for growing two or three dimensional mammalian cells within a culture medium facilitated by an electromagnetic field, and preferably, a time varying electromagnetic field. The cells and culture medium are contained within a fixed or rotating culture vessel, and the electromagnetic field is emitted from at least one electrode. In one embodiment, the electrode is spaced from the vessel. The invention further provides methods to promote neural tissue regeneration by means of culturing the neural cells in the claimed system. In one embodiment, neuronal cells are grown within longitudinally extending tissue strands extending axially along and within electrodes comprising electrically conductive channels or guides through which a time varying electrical current is conducted, the conductive channels being positioned within a culture medium.

Abstract: Systems and methods for processing light from multiple fields (48, 54, 55) of view without excessive machinery for scanning optical elements. In an exemplary embodiment of the invention, multiple holographic optical elements (41, 42, 43, 44, 45), integrated on a common film (4), diffract and project light from respective fields of view.

Abstract: A method and system provide physiological feedback for a patient and/or physician. At least one physiological effect experienced by a body part of a patient is measured non-invasively. A three-dimensional graphics model serving as an analogous representation of the body part is altered in accordance with the measurements. A binocular image signal representative of the three-dimensional graphics model so-altered is displayed for the patient and/or physician in a virtual reality enviromnent.

Abstract: Systems and methods that employ a phase change material to provide thermal control of electric propulsion devices (thrusters). A spacecraft is configured to have an electric propulsion thruster. The electric propulsion thruster is surrounded with a phase change material. Suitable phase change materials include high-density polyethylene (HDPE), waxes, paraffin materials, and eutectic salts. The spacecraft is launched into orbit. The electric propulsion thruster is fired for a predetermined period of time. Heat generated by the electric propulsion thruster is absorbed and stored in the phase change material while the thruster is firing. The stored heat is dissipated into space after the thruster has stopped firing.

Abstract: A loop heat pipe cooling system for use on a spacecraft. The loop heat pipe cooling system has loop heat pipes routed from internally facing surfaces of one or more internally located equipment panels to externally located radiator panels. Heat is collected at evaporator ends of each loop heat pipe and transported to condenser ends of the respective loop heat pipe. The condenser ends of the loop heat pipes may either be embedded within the radiator panel or externally mounted and coupled to the radiator panel using a loop heat pipe condensing flange. Fixed conductance heat pipes may also be used in any or all of the internal panels and radiator panels in order to collect and distribute heat loads to and from the loop heat pipes.

Abstract: A waveguide slot array antenna system, for use with a communications system 30 disposed on a satellite. The waveguide slot array antenna system comprises a feed waveguide having an input port and multiple output ports, a waveguide slot array having a plurality of slots formed therein that is coupled to the feed waveguide, and a waveguide lens disposed adjacent to the waveguide slot array. The phase of each contributing radiating waveguide is controlled to achieve radiation pattern shaping. Inner dimensions of the rectangular waveguides are designed to provide a phase velocity inside each waveguide that results in the appropriate radiated phase at the output of the waveguides. The phase radiated by each rectangular waveguide is determined by design, and the radiation pattern that results from the combined contributions of the array can be shaped to produce a complex radiation contour.

Abstract: An equalizer that couples a dual-mode dielectric resonator to a planar transmission line, creating an all-pass network. Coupling is achieved using circular polarization of the electromagnetic field in the dielectric resonator. The all-pass, non-reciprocal network is realized by the use of circular polarized energy and an offset cross shaped, through transmission line.

Abstract: Changes in intracranial pressure can be measured dynamically and non-invasively by monitoring one or more cerebrospinal fluid pulsatile components. Pulsatile components such as systolic and diastolic blood pressures are partially transferred to the cerebrospinal fluid by way of blood vessels contained in the surrounding brain tissue and membrane. As intracranial pressure varies these cerebrospinal fluid pulsatile components also vary. Thus, intracranial pressure can be dynamically measured. Furthermore, use of acoustics allows the measurement to be completely non-invasive. In the preferred embodiment, phase comparison of a reflected acoustic signal to a reference signal using a constant frequency pulsed phase-locked-loop ultrasonic device allows the pulsatile components to be monitored. Calibrating the device by inducing a known change in intracranial pressure allows conversion to changes in intracranial pressure.

Abstract: An attitude control system comprising a controller and a noise screen device coupled to the controller. The controller is adapted to control an attitude of a vehicle carrying an actuator system that is adapted to pulse in metered bursts in order to generate a control torque to control the attitude of the vehicle in response to a control pulse. The noise screen device is adapted to generate a noise screen signal in response to the control pulse that is generated when an input attitude error signal exceeds a predetermined deadband attitude level. The noise screen signal comprises a decaying offset signal that when combined with the attitude error input signal results in a net attitude error input signal away from the predetermined deadband level to reduce further control pulse generation.

Abstract: A series of tuning brackets are mounted on the microwave waveguide manifold at positions between the input waveguide/filter couplings. These brackets constrain the manifold and are constructed with adjustment screws extending through the brackets and mechanically connected to the manifold. The movement of the adjustment screw will tend to deform the manifold dimensions resulting in a fine adjustment of the wavelength (&lgr;) of the multiplexer.

Abstract: The system for the optimization of inter-satellite links has a terminal comprising a multiplexer (1) which is connected to the output of a transmission unit (2) and has a subchannel input that is connected to an evaluation unit (3). The terminal also has a demultiplexer (5), which is connected to the input of a receiver unit (6) and has a subchannel output that is connected to an optimization unit (8). With the aid of an auxiliary channel established through the multiplexer and demultiplexer in addition to the transmission channel present for user-information data, it becomes possible to transmit operation-internal data pertaining to at least one continually measured parameter to the optimization unit of the opposite terminal via the evaluation unit (3).

Abstract: A real-time emissions reporting system includes an instrument module adapted to be detachably connected to the exhaust pipe of a combustion engine to provide for flow of exhaust gas therethrough. The instrument module includes a differential pressure probe which allows for determination of flow rate of the exhaust gas and a gas sampling tube for continuously feeding a sample of the exhaust gas to a gas analyzer or a mounting location for a non-sampling gas analyzer. In addition to the module, the emissions reporting system also includes an elastomeric boot for detachably connecting the module to the exhaust pipe of the combustion engine, a gas analyzer for receiving and analyzing gases sampled within the module and a computer for calculating pollutant mass flow rates based on concentrations detected by the gas analyzer and the detected flowrate of the exhaust gas. The system may also include a particulate matter detector with a second gas sampling tube feeding same mounted within the instrument module.

Abstract: A family of supersonic injectors for use on spaceplanes, rockets and missiles and the like is disclosed and claimed. Each injector maintains a specific constant (uniform) Mach number along its length when used while being minimally intrusive at significantly higher injectant pressure than combustor freestream total pressure. Each injector is substantially non-intrusive when it is not being used. The injectors may be used individually or in a group. Different orientations of the injectors in a group promotes greater penetration and mixing of fuel or oxidizer into a supersonic combustor. The injectors can be made from single piece of Aluminum, investment cast metal, or ceramic or they can be made from starboard and port blocks strapped together to accurately control the throat area. Each injector includes an elongated body having an opening which in cross section is an hour glass (venturi shaped) and the opening diverges in width and depth from the bow section to the stem section of the opening.