Abstract: A flying vehicle has wheels for highways, and a body and an engine. The body, engine and load define a center of mass (CG). Shrouded fans are located about the CG so as to produce, in conjunction with air jet redirection apparatus, the torques required to assume various attitudes. In one embodiment, an upper shrouded fan, with a diameter no greater than eight feet, produces an air jet, centered above the CG, for lifting the body. A second shrouded fan, smaller than the first, produces an air jet for lift, centered below the center of mass, on the longitudinal axis of the vehicle, forward of the CG. Third and fourth paired shrouded fans produce air jets for lift, centered below the CG, on either side of the longitudinal axis of the vehicle, toward the rear of the body. The paired second and third fans have equal diameters, no greater than half of the diameter of the upper fan, to keep the total width eight feet.

Abstract: An optical sensor is described comprising a first optical fiber and a first reflective member. The first optical fiber has a first predetermined length of graded-index multimode optical fiber attached to its end. The first reflective member and the first optical fiber are arranged such that a gap is formed between the unattached end of the graded-index multimode optical fiber and the first reflective member. Also described is a rugged sensor design incorporating the first optical fiber and first reflective sensor as well as a method for providing the predetermined length of graded-index multimode fiber at the end of the first optical fiber. Finally, a readout system for an optical sensor is also described which comprises two optical paths differing in length by an amount equal to an optical path distance in the optical sensor. The readout system also comprises an optical source having a wavelength differing from that of the optical sensor, a modulator and a controller.

Abstract: An optical memory material includes a two-photon storage component which can be written from a first to a second state in response to WRITE light, mixed with a signal component which fluoresces by one-photon absorption only at the written locations in response to READ light. The storage material may be a fulgide. The memory material may also include a frequency upconversion material to aid writing. Writing is performed by a spatial light modulator (SLM) with a dynamic focussing system, for concentrating sufficient power at WRITE locations for nonlinear two-photon absorption. Crosstalk is avoided during simultaneous writing in some embodiments, by spacing the individual WRITE beams apart by an integer number of inter-beam spacings, so that non-adjacent datels are written simultaneously in a "paragraph," and the non-written areas are written at a different time with different paragraphs.

Abstract: A perfusion balloon catheter (10), as for angioplasty by dilatation, has the balloon (30) formed so that, when inflated within a vas or coronary artery, one or more channels (40) are provided for the flow of bodily fluids or blood past the inflated balloon. In one embodiment, the balloon has a toroidal shape which defines a central open channel. In order to avoid closure of the central channel when the balloon inflation pressure is increased to distend the vas within which it is placed, a portion (44) of the balloon is made from a relatively elastic membrane, and the portion of the balloon (244) adjacent the channel (40) is made from a relatively less elastic material, or a rigid material, whereby additional pressure does not cause channel closure.

Abstract: A method for fabricating a hard faced fan blade containment system for turbofan aircraft engines, and the product resulting from that method. The product combines a hard facing material, a high strength fiber and an elastomeric binder to form a fan blade containment system which is lightweight and effectively retains fan blade fragments. The method consists of lightly bonding layers of high strength fibers together with a small amount of elastomeric binder so that they work in unison as a composite to contain a failed fan blade rather than as individual layers which are subject to sequential failure. In addition, a hard material such as ceramic or heat treated steel is encapsulated in an elastomer and bonded to the impact face of the containment system to blunt sharp edges of failed blade fragments and to spread the impact energy of the blade fragments over a larger area of the high strength fiber backing.

Abstract: An acoustic catheter reduces transmission losses and unwanted heating of the transmission member by driving the catheter a rotary motor. The catheter includes an elongated body and a shaft extending longitudinally therethrough. The shaft is adapted for coupling to a rotary motor. A rotary-to-axial motion converter is coupled to the shaft at distal end of the catheter, for converting rotary shaft motion into axial acoustic motion. In one embodiment, the rotary-to-axial motion converter includes a swash plate driven by the shaft. The swash plate defines a surface which, at an angularly fixed reference point, moves axially in response to the rotary motion of the swash plate. A follower bears on the swash plate, for moving axially in response to axial motion of the follower. The follower includes a projection bearing on the swash plate and a spring urging the follower toward the swash plate. In one embodiment, the swash plate has a sinusoidal surface, while another embodiment has notches cut into the surface.

Abstract: Dental or endodontic instruments such as drills, files, rasps, broaches, reamers, and the like are arranged to allow radiation of electromagnetic energy into a man-made or natural cavity in the tooth under treatment. The energy may be in the form of microwave or radio-frequency (RF) radiation. The energy raises the temperature of the surrounding tooth material, which tends to disinfect the material as a direct consequence of the temperature. Also, if a disinfectant material is additionally introduced into the tooth cavity, the temperature of the disinfectant material itself may be raised, which enhances its activity. In the particular application to the removal of degenerated pulp, the instrument may be introduced, and electrical or electromagnetic power applied to coagulate the pulp about the instrument, allowing more complete removal of the pulp. The dental instrument may be used with an RF energy delivery system for application of particular amounts of energy per unit time (power).

Abstract: An apparatus for reducing acoustic radiation from an enclosure containing a fluid includes one or more vibration sensors in communication with surfaces of the enclosure. The vibration sensors feed signals corresponding to detected vibrations in the surface to a radiation filter. The radiation filter assigns weights to the signals and generates a summation signal which is then input to a control unit, with the summation signal ideally representing only those vibrations that will actually radiate from the enclosure. The control unit uses a reference signal and the summation signal to calculate a cancellation waveform to offset the cause of the detected vibrations. The cancellation signal is input to a fluid displacement unit which applies pressure oscillations to the fluid corresponding to the cancellation waveform.

Abstract: Each of the acoustic transducers (elements) of an array has a maximum dimension of less than .lambda.. They are located at the vertices of a regular polyhedron, which may be an icosahedron (12 elements), or a dodecahedron (20 elements). This placement effectively locates the elements on the surface of a sphere with diameter selected to provide an interelement spacing of .lambda./3 to 2.lambda./3. The signals are delayed for phasing to form directive "beams." A second array includes elements located at the vertices of a smaller polyhedron centered at the same point and included within the first array, and operated at a higher frequency than the outermost array. In order to reduce the effects of shadowing, the locations of the transducers of the smaller included array are selected to lie on radials passing through the centroids of the faces of the polygon defining the larger array.

Abstract: In accordance with the invention, a fishhook includes a shank portion and a curved hook portion. The hook portion includes a point at its end remote from the shank, and defines a cavity adjacent the point. The opening of the cavity faces the shank. A movable barb is affixed for movement between a retracted position, in which the barb is substantially contained within the cavity, and an extended position, in which at least a portion of the barb protrudes. A spring arrangement urges the barb toward its protruding position. In one embodiment of the invention, a hinge pin is affixed to the hook portion adjacent the point, and transfixes the movable barb for rotary motion between the retracted and protruding positions. The spring arrangement is a leaf spring affixed to an edge of the barb. A stop is provided to prevent excessive rotary motion.

Abstract: A fault tolerant communication arrangement, for switching parallel N-bit information among a plurality of stations, includes an M-bit crossbar switch, where M is greater than N by a number S of supernumerary or spare bit paths. At each station, an interface unit monitors for errors, and when an error is identified to a bit in the transmission path, routes the defective bit to one of the spare bit paths. All stations reroute data from the defective bit path to the same spare bit path. Error coding information is generated at the transmitting interface unit, and transmitted over some of the supernumerary bit paths, and when the number of defective bit paths reduces the number of available supernumerary bit paths to zero, the bit intensity of the error coding is reduced, to free additional supernumerary paths. In a system in which some of the stations include memory, a failure of a memory bit at a particular address is, in effect, a failure of that bit in an overall transmission path.

Abstract: A short horn antenna (10) adapted for array use includes a rectangular waveguide with broad upper (12) and lower (14) walls and narrow side walls (16, 18), defining a radiating aperture (20) and a feed end closed off by a shorting plate (22). A stepped upper ridge (26) has a slot (50) adjacent the shorting plate, and a shorter stepped lower ridge (46) has a corresponding slot. An unbalanced transmission line (75) extends through the shorting wall, and the smaller conductor (76) extends into the waveguide as an electric probe (60). The probe includes a first portion (64), extending parallel to the waveguide axis (8) and into the slot in the upper ridge. The probe (60) also includes a second portion (66) extending at an angle (90.degree.) relative to the first portion (64) of the probe (60).

Abstract: A process and apparatus for making high purity aluminum nitride from organometallic aluminum, such as an alkylaluminum compound. A gaseous alkylaluminum compound and gaseous ammonia are introduced into a heated reaction zone where the gases are mixed and high purity aluminum nitride is produced. The high purity aluminum nitride is collected in the form of a powder or deposited as a thick, dense layer on an appropriate substrate mounted in the reaction chamber. A carrier gas such as hydrogen gas, may be used to conduct the alkylaluminum compound from a suitable reservoir containing liquid alkylaluminum compound to the reaction chamber. A preferred alkylaluminum compound is triethylaluminum.

Abstract: A resistance strip heater includes a pair of elongated, mutually parallel electrical conductors or buses lying on a dielectric substrate. Each bus includes a conductive region extending toward the other conductor, and the locations of the conductive regions of the two buses alternate along the lengths thereof. An elongated resistance arrangement has its axis of elongation parallel to the buses, is physically supported between the buses, and is electrically connected to mutually adjacent ones of the conductive regions, so that the resistance arrangement is electrically connected across the buses. In a particular embodiment of the invention, the resistance arrangement is a plurality of elongated chip resistors arranged in an array. The substrate may be a polyimide sheet, and a corresponding cover sheet may be used. The strip heater can be cut virtually anywhere along its length without affecting its operability.

Abstract: An antenna subject to standoff sidelobe barrage jamming exhibits a null in its sidelobe structure at a selectable elevation angle for all azimuth angles of interest. The null can be set to the elevation angles corresponding to the angle of the standoff jammers. The null is generated with the aid of an interferometer associated with each column of the antenna array. The interferometer produces a pattern having a plurality of lobes. The interferometer pattern is phased and amplitude adjusted relative to the antenna pattern of its associated column line array so that subtraction of the patterns causes one or more sidelobe of the antenna pattern to be at least partially canceled. An azimuth beamformer combines the elevation patterns of a plurality of column arrays, each connected to its own interferometer, to produce a pencil beam with a sidelobe structure exhibiting a null at the particular elevation angle.

Abstract: A method and apparatus for masking the presence and content of data transmissions includes a mobile transmitter which encodes the data by means of a pseudorandom spreading (PRS) code having a chip rate, and which transmits it at a carrier frequency. A masking transmitter remote from the mobile transmitter encodes a carrier at the same frequency with a second PRS sequence having the same chip rate, and transmits it at a power level higher than the power level of the mobile transmitter. A signal interceptor cannot separate the mobile and masking station carriers on a frequency basis. The relatively low-power mobile station PRS signal is difficult to detect in the presence of the high-power masking station code. The intended receiver (master station) receives an ensemble signal which is principally masking station signal. The master station regenerates the known masking station PRS code and subtracts it from the ensemble signal to leave a residue signal which contains the data-bearing mobile station PRS signal.

Abstract: A Kalman filter, for a dynamic system having a number N of different states and another number M of observational components, uses a fixed rectangular systolic array of N.times.(N+1) parallel data processing elements for a regular filter, and uses an array of (N+2).times.(N+3) processing elements for a fault-tolerant filter; the processing elements in either configuration are connected in a four-nearest-neighbors network. Each processor is capable of carrying out a commanded one of a plurality of different vector-data operations sets during each of eight passes through the array. The systolic array operates on the matrices in a pipeline manner, so that each pass through the processor array feeds the result back into the array to begin the next computation.

Abstract: A shape memory alloy (SMA) actuator predeformed in tension actuates a separation device mechanism. A segmented nut, which engages a threaded bolt to be held and released, is held together by a nut retainer that is movable with respect to the nut and is affixed to the SMA element. The SMA element is heated by an electrical resistance heater to cause it to return to its undeformed state, thereby moving the retainer relative to the nut segments. When the retainer disengages from the segments, the segments are free to move outwardly thereby releasing the bolt or other item. Ones of the shape memory alloy actuator have a plurality of parallelly arranged SMA elements, every other one of which is predeformed in compression and intermediate ones of which are predeformed in tension.

Abstract: A high-throughput bidirectional data communication channel is formed of a pipelined plurality M of stages, connected to the input/output (I/O) port of each of the pair of devices using the channel, and configured to allow interruptibility of data transmission by either device connected to the channel; either device may be sender or receiver and transmission of data may be interrupted by either device for any number of cycles and resumed without loss or duplication of data at the receiver. The channel uses pipelining to achieve longer distance parallel transmission of N plural data bits, while maintaining the maximum high speed throughput. The channel, and its associated data transfer protocol, supports bidirectional transmission of data between the two sourcing/terminating devices with maximum throughput being achieved by transmitting a word of parallel data during every clock cycle.

Abstract: A urinary catheter and system includes a catheter with a drain lumen which is coated with oligodynamic metal and preferably arranged with a coating of a more noble metal for creating an iontophoretic galvanic couple, which drives antimicrobial ions into solution. The exterior of the catheter is also coated in a similar manner to inhibit microbes migrating toward the bladder along the outer surface of the catheter. The system includes a flow rate control device which may be a one-way valve, a filter or both. A collection bag is coupled to the control device. The interconnecting hoses, the flow rate control device(s) and the collection bag are also coated on the interior with oligodynamic metal, preferably silver, and also with a more noble metal, preferably platinum.