Abstract: A system is provided for structural load assessment of an aircraft. An approximator may receive parameters related to a ground or flight event and calculate the resulting response load on the aircraft using a machine learning algorithm and a structural dynamics model of the aircraft. An analysis engine may compare the calculated response load to a corresponding design load for determining the structural severity of the ground or flight event on the aircraft. A maintenance engine may then automatically perform or trigger a maintenance activity for the aircraft in instances in which the structural severity of the ground or flight event causes a limit exceedance state of the aircraft or at least one structural element thereof.

Abstract: A dolly apparatus for door installation transports and facilitates the installation of multiple doors. The apparatus includes a frame. A plurality of wheels is coupled to and extends rearwardly from the frame. A support bracket is coupled to the frame and is configured to support a door thereon. A first guide member is coupled to and extends forwardly from the frame. The first guide member forms a first slot configured to receive a non-hinged side of the door therein. A pair of arms is coupled to the frame. The arms are positioned in spaced parallel relationship relative to each other and extend forwardly from the frame. A plurality of casters is provided and each is configured to contact a ground surface. One of the casters is coupled a first one of the arms. One of the casters is coupled to a second one of the arms.

Abstract: A method for diagnosing the health of a transducer may include transmitting a signal to a transducer to cause the transducer to transmit a stress wave into an object being monitored, wherein the signal has a predetermined frequency range or bandwidth. The method may also include receiving response data for the transducer and transforming the response data to data representative of an impedance curve of impedance versus frequency for the predetermined frequency range. The method may further include extracting selected parameters from the impedance curve to diagnose the health of the transducer.

Abstract: A method for diagnosing the health of a transducer may include transmitting a signal to a transducer to cause the transducer to transmit a stress wave into an object being monitored, wherein the signal has a predetermined frequency range or bandwidth. The method may also include receiving response data for the transducer and transforming the response data to data representative of an impedance curve of impedance versus frequency for the predetermined frequency range. The method may further include extracting selected parameters from the impedance curve to diagnose the health of the transducer.

Abstract: A method and system for detecting a hard landing or other high load event of an aircraft are disclosed. A heuristic algorithm may be used to estimate loads experienced by the aircraft during landing. The heuristic algorithm may use flight parameters and/or measured sensor information to estimate the loads. The heuristic algorithm may be trained by means of analytical loads predictions and/or test measurements. The heuristic algorithm may be updated during operation. This invention may potentially reduce the number of unnecessary structural inspections, and may also limit the scope of any such required inspections.

Abstract: A noise reduction system for use with an exhaust nozzle associated with a jet engine of an aircraft. The noise reduction system employs a plurality of flow-altering components disposed circumferentially about a lip portion of an exhaust nozzle. In one preferred form the flow-altering components each comprise piezoelectric transduction layers. The flow-altering components are caused to move in an oscillating manner by an AC signal applied thereto such that they move into and out of the exhaust gas emitted from the exhaust nozzle to achieve a desired degree of intermixing of the exhaust flow with the flow adjacent the exhaust nozzle. This produces a reduction in the noise generated by the jet engine. The noise reduction can be utilized during takeoff conditions of an aircraft.

Abstract: A piezoelectric device connected to a vibration source converts vibration energy to electrical current. A plurality of pairs of oppositely polarized piezoelectric wafers deflect to produce an electrical current. Each pair of wafers are arranged back-to-back and electrically joined together. The plurality of pairs of wafers are each connected to a set of micro-machined parts. Each pair of wafers form a bimorph, configured as a cantilevered beam attached to a set of parts to form an element. Each cantilevered beam has a mass weighted first end and is fixedly attached to one or more flexible sheaths on a second end. A plurality of elements form a cell unit. A plurality of cell units form an array. The electrical current produced varies by the number of elements per cell unit, and/or with the number of cell units per array.

Abstract: An energy harvesting device is provided. The energy harvesting device includes structural members covered with piezoelectric material resonating at different primary frequencies. As the structure to which the energy harvesting device is secured vibrates over a range of frequencies, more than one member resonates or is close to resonance. As such, multiple members work simultaneously to create electrical energy.

Abstract: A molded plastic container and closure is provided with a double lock, the top lock being formed by the container rim and a protrusion on the inside of the closure channel. The bottom lock is formed by a segmented flange on the container sidewall and a second annular protrusion on the inside of the closure skirt. A zig-zag tear line allows the second lock to be removed thereby to create alternating areas of greater and lesser clearance between the newly formed skirt edge and a second, lower flange on the container sidewall.

Abstract: A noise reduction system for use with an exhaust nozzle associated with a jet engine of an aircraft. The noise reduction system employs a plurality of flow-altering components disposed circumferentially about a lip portion of an exhaust nozzle. In one preferred form the flow-altering components each comprise piezoelectric transduction layers. The flow-altering components are caused to move in an oscillating manner by an AC signal applied thereto such that they move into and out of the exhaust gas emitted from the exhaust nozzle to achieve a desired degree of intermixing of the exhaust flow with the flow adjacent the exhaust nozzle. This produces a reduction in the noise generated by the jet engine. The noise reduction can be utilized during takeoff conditions of an aircraft.

Abstract: An injection molded polyethylene paint can comprising the combination of a straight sided plastic container having a snap ring structure spin-welded to the upper peripheral edge thereof and a snap-on lid. The snap ring structure is of the reentrant design and provides an annular locking structure radially interior of a large volume depression. A snap-on lid has legs which fit over the annular structure and sealingly engage inward and outward exterior surfaces thereof. The lid further comprises a pry ring which lies within the large annular depression of the reentrant portion of the snap ring. A brush wiper ring may be provided integrally with the snap ring. All components are nestable and stackable; the containers are stackable with and without the snap ring.

Abstract: A molded plastic container and closure is provided with a double lock, the top lock being formed by the container rim and a protrusion on the inside of the closure channel. The bottom lock is formed by a segmented flange on the container sidewall and a second annular protrusion on the inside of the closure skirt. A zig-zag tear line allows the second lock to be removed thereby to create alternating areas of greater and lesser clearance between the newly formed skirt edge and a second, lower flange on the container sidewall.

Abstract: A coupling coefficient is a measure of the effectiveness with which a shape-changing material (or a device employing such a material) converts the energy in an imposed signal to useful mechanical energy. Device coupling coefficients are properties of the device and, although related to the material coupling coefficients, are generally different from them. This invention describes a class of devices wherein the apparent coupling coefficient can, in principle, approach 1.0, corresponding to perfect electromechanical energy conversion. The key feature of this class of devices is the use of destabilizing mechanical pre-loads to counter inherent stiffness. The approach is illustrated for piezoelectric and thermoelectrically actuated devices. The invention provides a way to simultaneously increase both displacement and force, distinguishing it from alternatives such as motion amplification, and allows transducer designers to achieve substantial performance gains for actuator and sensor devices.

Abstract: A piezoceramic vibration control device in which stiffness is established by a capacitor in shunt with piezoceramic element of the device. The device can be formed of a stack of piezoceramic elements bonded to one another and precompressed by a spring. A control system is arranged to tune the natural frequency of the vibration control device to a disturbance frequency or s primary structural response frequency by varying the capacitance of the capacitor.

Abstract: The reinforced catheter sensor probe for intravascular use includes an aramid strand that extends along the length of the electromagnetic conduits and is bonded thereto. A greater than ten fold increase in tensile strength is thereby achieved. Additionally, the inherent strength of flexibility of the reinforcing strand ensures that a positive interconnection with the distal end of the sensor probe is maintained in the event the sensor probe is subjected to loads that cause its relatively more fragile components to sever. A protective, strain relieving introducer catheter is also provided to substantially prevent kinking and breakage of the sensor probe where the introducer catheter bends.

Abstract: The calibration cuvette apparatus for storing and calibrating a chemical sensor in a tonometered solution includes an upper cuvette section and a lower cylindrical valve section for alternately sealing the cuvette section and admitting a gas mixture to the cuvette section. The upper cuvette section has relatively narrow diameter upper and lower ends on either side of a wide diameter middle portion. The cuvette section is adapted to receive the sensor and retain the sensor in a fluid bath in the cuvette section so that the chemical sensor portion is disposed approximately in the center of the wide middle portion of the cuvette section. The chamber formed within the cuvette section is thus shaped so as to maintain the sensor in a position in the fluid bath so that any gas bubbles within the chamber will not dry the sensor. A lower end portion of the cuvette section includes a gas communication inlet for introducing gas into said chamber to equilibrate the tonometered buffer solution.

Abstract: A fuel cell (10) system in which a nitrogen (N.sub.2) gas is used on the anode section (11) and a nitrogen/oxygen (N.sub.2 /O.sub.2) gaseous mix is used on the cathode section (12) to maintain the cathode at an acceptable voltage potential during adverse conditions occurring particularly during off-power conditions, for example, during power plant shutdown, start-up and hot holds. During power plant shutdown, the cathode section is purged with a gaseous mixture of, for example, one-half percent (0.5%) oxygen (O.sub.2) and ninety-nine and a half percent (99.5%) nitrogen (N.sub.2) supplied from an ejector (21) bleeding in air (24/28) into a high pressure stream (27) of nitrogen (N.sub.2) as the primary or majority gas. Thereafter the fuel gas in the fuel processor (31) and the anode section (11) is purged with nitrogen gas to prevent nickel (Ni) carbonyl from forming from the shift catalyst. A switched dummy electrical load (30) is used to bring the cathode potential down rapidly during the start of the purges.

Abstract: An apparatus to be attached onto the jaw of a human being to cause the jaw to continuously move between its open and closed position. The apparatus incluses a cam arrangement mounted in conjunction with the teeth of the jaw. The cam arrangement is to be continuously driven by a motor located exteriorly of the jaw to produce the continuous jaw movement.