摘要:
A system and method are provided for monitoring performance capacity of a piezoelectric material that may form part of an actuator or sensor device. A switch is used to selectively electrically couple an inductor to the piezoelectric material to form an inductor-capacitor circuit. Resonance is induced in the inductor-capacitor circuit when the switch is operated to create the circuit. The resonance of the inductor-capacitor circuit is monitored with the frequency of the resonance being indicative of performance capacity of the device's piezoelectric material.
摘要:
Magnetic field response sensors designed as passive inductor-capacitor circuits produce magnetic field responses whose harmonic frequencies correspond to states of physical properties for which the sensors measure. Power to the sensing element is acquired using Faraday induction. A radio frequency antenna produces the time varying magnetic field used for powering the sensor, as well as receiving the magnetic field response of the sensor. An interrogation architecture for discerning changes in sensor's response frequency, resistance and amplitude is integral to the method thus enabling a variety of measurements. Multiple sensors can be interrogated using this method, thus eliminating the need to have a data acquisition channel dedicated to each sensor. The method does not require the sensors to be in proximity to any form of acquisition hardware. A vast array of sensors can be used as interchangeable parts in an overall sensing system.
摘要:
A self-contained avionics sensing and flight control system is provided for an unmanned aerial vehicle (UAV). The system includes sensors for sensing flight control parameters and surveillance parameters, and a Global Positioning System (GPS) receiver. Flight control parameters and location signals are processed to generate flight control signals. A Field Programmable Gate Array (FPGA) is configured to provide a look-up table storing sets of values with each set being associated with a servo mechanism mounted on the UAV and with each value in each set indicating a unique duty cycle for the servo mechanism associated therewith. Each value in each set is further indexed to a bit position indicative of a unique percentage of a maximum duty cycle for the servo mechanism associated therewith. The FPGA is further configured to provide a plurality of pulse width modulation (PWM) generators coupled to the look-up table. Each PWM generator is associated with and adapted to be coupled to one of the servo mechanisms.
摘要:
An optical assembly is formed by one or more piezoelectric fiber composite actuators having one or more optical fibers coupled thereto. The optical fiber(s) experiences strain when actuation voltage is applied to the actuator(s). Light passing through the optical fiber(s) is wavelength tuned by adjusting the actuation voltage.
摘要:
A hydraulic pump comprises (1) an outward ring (24), including demountable blocks (30) comprising piston cylinders (32), and an inward ring (21), comprising a ring cam (23), coupled through a drive shaft (8) to the blades of a turbine (4). To enable maintenance, the outward ring is decoupled from a torque limiting device (16, 17) and rotated relative to the inward ring. Demountable blocks are then removed from the outward ring using a crane (61) including a line (62) extending from above the centre of mass of the demountable block and including a resilient portion (66) so that although the crane supplies the majority of the force required to remove the demountable block, an operator provides some force, enabling the process to be controlled. The method is suitable for maintaining large hydraulic pumps in wind turbine nacelles (2).
摘要:
A method for manufacturing a semiconductor device includes providing a patterned hard-mask layer. The hard-mask layer is provided on an exposed surface of one or more layers to be patterned of a semiconductor intermediate product. The hard-mask layer covers the exposed surface in covered areas of the one or more layers to be patterned and does not cover the exposed surface in bared areas of the one or more layers to be patterned. One or more recesses are formed in the layers to be patterned by at least partially removing the layers to be patterned in the bared areas. The hard-mask layer is ten removed. After removing the hard-mask layer the recess is filled with a filling material.
摘要:
Transport brackets are welded onto the top surface of the mower deck, each transport bracket having vertical plates with holes extending transversely through the plates. Pins extend through at least one hole in the plates and are secured to a rear mounted hitch of a tractor. The mower deck may be lifted and transported in a raised position behind the tractor, and also may be pivoted to a position for servicing.
摘要:
A storage means provides sealed storage for contents. A closure means is fused to a container by application of an electromagnetic field providing a permanent and hermetic seal between the closure and the container. The closure further includes a removable panel to provide access to the contents of the container.
摘要:
A method of producing an alkyl ester. The method comprises providing an alcohol and a triglyceride or fatty acid. An expanding gas is dissolved into the alcohol to form a gas expanded solvent. The alcohol is reacted with the triglyceride or fatty acid in a single phase to produce the alkyl ester. The expanding gas may be a nonpolar expanding gas, such as carbon dioxide, methane, ethane, propane, butane, pentane, ethylene, propylene, butylene, pentene, isomers thereof, and mixtures thereof, which is dissolved into the alcohol. The gas expanded solvent may be maintained at a temperature below, at, or above a critical temperature of the expanding gas and at a pressure below, at, or above a critical pressure of the expanding gas.
摘要:
A boat docking system having supports, a boat lift and a roof, the roof covering the dock. A fixed cover disposed over the boat dock and beneath the roof, the fixed cover attached to the supports by support brackets. The fixed cover includes a tarp having a roof and walls defining a covered space into which the boat lift can raise the boat. The fixed cover reduces the need for hard to handle traditional boat covers that attach directly to the boat to keep dust, dirt and insects out of the boat during a period of storage.