Abstract: A method for passively shimming a magnet having a magnetic field with an inhomogeneity and having N possible passive shim locations. The magnetic field is mapped. A function is defined related to the mapped field as affected by N shim variables of positive shim strength and M shim variables of negative shim strength. A computer optimization code is run which calculates the positive strengths of the N shim variables and the negative strengths of the M shim variables which minimizes the defined function. Positive strengths of passive shims are added to the magnet corresponding to the calculated positive strengths of the N shim variables and positive strengths of passive shims are removed from the magnet corresponding to the calculated negative strengths of the M shim variables.

Abstract: A planar magnetic resonance imaging (MRI) magnet having a superconductive coil assembly including a toroidal-shaped coil housing which surrounds a bore, has a longitudinal axis, and contains at least three concentric, annular-shaped superconductive coils coaxially aligned with the axis. The coils produce a magnetic resonance imaging volume having a center located outside the bore. Preferably, the bore is generally completely filled with magnetic material, and the magnetic resonance imaging volume is located completely outside the bore which provides for improved patient and physician access during MRI-guided biopsy as well as during MRI imaging.

Abstract: A superconducting field winding assemblage for an electrical machine, such as a rotary generator or a linear motor. The field winding assemblage includes at least two pole assemblies. Each pole assembly has a direction of motion, a solid core, a superconductive coil assembly generally surrounding the solid core, and a first cooling conduit. The superconductive coil assembly has a generally longitudinally extending axis positioned generally perpendicular to the direction of motion and has an epoxy-impregnated, generally racetrack-shaped superconductive coil having a minor axis positioned generally parallel to the direction of motion. The first cooling tube contains a gaseous cryogen (such as gaseous helium) and is positioned to be in thermal contact with the superconductive coil.

Abstract: A gas-path leakage seal for generally sealing a gas-path leakage-gap between spaced-apart first and second members of a gas turbine (such as first and second segments of a gas turbine combustor casing). The seal includes a generally imperforate foil-layer assemblage which is generally impervious to gas, is located in the leakage-gap, is spaced apart from the first member, and has a first foil layer. The seal also includes a cloth-layer assemblage contacting the first member and having a first cloth layer generally enclosing and generally enclosingly-contacting the foil-layer assemblage. The first foil layer is made from a metal, ceramic, and/or polymer. The first cloth layer is made from metal, ceramic, and/or polymer fibers. The foil assemblage provides for sealing and flexibility, and the cloth assemblage provides for wear resistance and flexibility. The seal accommodates different surface shapes, assembly misalignment, vibration, and differential thermal growth of the gas turbine members.

Abstract: A transmission for driving an agitator in a washing machine includes a housing, an input shaft for being driven by a motor, and an output shaft for driving the agitator. The input shaft includes a crank disposed in the housing, and the output shaft includes a pinion disposed in the housing adjacent to the crank. A yoke is slidably mounted in the housing between the crank and pinion, and includes a rack operatively engaging the pinion along a pitchline, and a slot having a slot axis disposed perpendicularly to the pitchline which receives therein a slider rotatably joined to the crank. Rotation of the crank sinusoidally reciprocates the rack as the slider reciprocates in the slot, and reciprocation of the rack sinusoidally oscillates the pinion for driving the output shaft with minimum peak torque and drive power.

Abstract: A lightweight, impact-resistant gas turbine blade, such as an aircraft engine fan blade, includes attached-together first-metal and second-composite segments together defining an airfoil portion. The first segment includes entirely the suction side, leading edge, and trailing edge from the blade root to the blade tip and further includes partially the pressure side near the leading and trailing edges from the blade root to the blade tip. The second segment includes partially the pressure side from near the leading edge to near the trailing edge from the blade root to near the blade tip.

Abstract: An apparatus and method are provided for calibrating a densitometer based sensor for measuring the linear density of the shot particles passing through a shot peening system to ensure that mass flow rate readings and shot velocity readings calculated therefrom are accurate. The apparatus comprises a probe having a plurality of randomly distributed particles configured to have a linear density substantially equal to the linear density of shot which the sensor should experience during operation of the shot peening system at desired parameters.

Abstract: A superconductive magnet has a superconductive coil surrounded by a thermal shield surrounded by a vacuum enclosure. The thermal shield has one and preferably several flexible layers of thermally conductive material. A first flexible blanket of multi-layer thermal insulation surrounds the thermal shield within the vacuum enclosure, and a second such flexible blanket surrounds the superconductive coil within the thermal shield. A cryocooler coldhead has a first stage in thermal contact with each of the flexible layers of the thermal shield. At least most of the weight of the thermal shield is supported by the flexible blankets.

Abstract: A superconductive-magnet electrical circuit includes a superconductive-coil assemblage having first, second, third, and fourth coil portions sequentially coupled together in series. A bipolar current-bypass electrical-circuit element (such as a pair of diodes opposingly coupled together in parallel) has:an impedance less than generally one-thousandth that of the coil portions; a first terminal coupled in parallel with the first and second coil portions; and a second terminal coupled in parallel with the third and fourth coil portions. A localized quench in one coil portion is quickly shared with the other coil portions to reduce damage from the quench. A resistor has a lead coupled in parallel with the second and third coil portions to limit quench voltages.

Abstract: A method for making an electrical coil such as a superconductive switch or an energy dump resistor. The midportion of a coil wire, whose ends are wound around two supply spools, is looped around a radially-extending pin on a shaft. The shaft is turned in one direction and the coil wire is guided such that segments are paid out from the first supply spool and sections are paid out from the second supply spool, such segments and sections being wound from the middle to a corresponding end, then being wound from the corresponding end to the middle where they are crossed over, and then being wound from the middle to the other associated end. A stratum of electrical insulation is positioned, at the appropriate time, on the second segment and second section, and, in the case of the switch, an electrical heater is positioned, at the appropriate time, on the first segment and first section.

Abstract: A method for operating a superconductive magnet having a superconductor. The magnet is ramped to generally the design current. After that, the magnet is brought to an annealing temperature which is above the operating temperature and below the critical temperature. After that, the magnet is shimmed at a shimming temperature which is at least as cold as the annealing temperature. After that, the magnet is used, at the operating temperature, for a predetermined purpose, such as MRI imaging for medical diagnosis. Preferably, the superconductor has less than twenty-five superconductive filaments.

Abstract: A lightweight, impact-resistant gas turbine blade, such as an aircraft engine fan blade, has a metal solid section, composite or structural/syntactic foam segments, and metal solid spars all attached together to define an airfoil portion. The solid section includes the leading edge, blade tip, and trailing edge. The segments together are bounded in part by the solid section near the leading edge, blade tip, and trailing edge. The solid spars separate and are attached to the segments.

Abstract: A nondestructive evaluation method is described for ultrasonic evaluation and detection of features in polycrystalline materials, such as grain orientation (e.g. texturing) or grain boundary orientation. The method may, for example, be employed to detect diffusion bonds that contain undesirable planar grain boundary arrays. The method utilizes time of flight statistics gathered from reflections associated with incident ultrasonic signals directed into a plurality of locations within the material.

Abstract: A superconductive-magnet electrical circuit for protecting a superconductive magnet from damage during a quench in the superconductive magnet coil assemblage. A first circuit portion detects the quench. A pilot superconductive switch has its superconductive wire portion superconductively coupled in series with the coil assemblage and has its resistive heater portion, which is activated by the first circuit portion, located near the superconductive wire portion. A second circuit portion (such as a resistive heater or an energy dump resistor) quench protects the coil assemblage and is triggered by the superconductive wire portion switching from the superconductive to the resistive mode.

Abstract: A method for passively shimming an open magnet having a magnetic field with an inhomogeneity including an amount of positive 2, 0 Legendre polynomial harmonics. The magnetic field is mapped and the amount of positive 2, 0 Legendre polynomial harmonics of the mapped magnetic field is determined. An adjusted magnetic field is defined equal to the mapped magnetic field minus a nonzero portion of the determined amount of positive 2, 0 Legendre polynomial harmonics. A computer shim code is run which calculates adding shims to reduce the inhomogeneity of the adjusted magnetic field. Shims are added to the open magnet as calculated from the running of the computer shim code.

Abstract: An active noise control subassembly for reducing noise caused by a source (such as an aircraft engine) independent of the subassembly. A noise radiating panel is bendably vibratable to generate a panel noise canceling at least a portion of the source noise. A piezoceramic actuator plate is connected to the panel. A back plate is spaced apart from the first plate and the panel with the panel positioned between the source noise and the back plate. A pair of spaced-apart side walls each generally abut the panel and the back plate so as to generally enclose a back cavity. A mechanism is provided for varying the panel resonating frequency by varying the state of the back cavity (such as by varying its fluid pressure and/or volume) while the panel is undergoing bending vibrations.

Abstract: A gas turbine subassembly having a stator, a rotor, and an annular brush seal which is attached to the stator and whose free end is in line-to-line contact with a first circumferential portion of the rotor's outside surface during a first rotation/load state (such as a full-speed/full-load state of a power-plant gas-turbine rotor). A longitudinally-adjoining second circumferential portion (such as a groove) has a smaller diameter than that of the first circumferential portion. The rotor and stator together undergo a predetermined differential thermal movement when the rotor transitions to a second rotation/load state (such as a turning-gear/no-load state). During such movement, the free end of the brush seal moves radially inward and longitudinally across the second portion, preferably without any contact, to minimize or eliminate brush seal wear.

Abstract: A closed magnetic resonance imaging (MRI) magnet has a single superconductive coil assembly including a toroidal-shaped coil housing containing a pair of superconductive main coils and at least one additional superconductive main coil. A pair of generally-non-permanently-magnetized ferromagnetic rings is spaced radially inward and apart from the superconductive main coils. The ferromagnetic rings allow the design of a shorter MRI magnet because the ferromagnetic rings overcome the gross magnetic field distortions in the imaging volume of the magnet (created by removing some of the additional longitudinally-outermost superconductive main coils, otherwise used in the magnet, to make the magnet shorter) to produce a magnetic field of high uniformity within the imaging volume.

Abstract: An active noise control subassembly array for reducing noise caused by a source (such as an aircraft engine). A pair of subassemblies each has a piezoceramic-driven noise radiating panel to generate a panel noise canceling at least some of the source noise. A front plate is spaced apart from the panel and has a sound exit port. A first pair of spaced-apart side walls each generally abuts the panel and the front plate so as to generally enclose a front cavity to define a resonator. A back plate is spaced apart from the panel by a second pair of side walls. The pair of subassemblies are spaced apart to create a space between their adjacent side walls. A third subassembly is similar to the pair of subassemblies but may have a different resonant frequency and is positioned such that the back plates of the subassembly pair serve as the front plate of the third subassembly with the space between the subassembly pair serving as the sound exit port of the third subassembly.

Abstract: A gas-path leakage seal for generally sealing a gas-path leakage-gap between spaced-apart first and second members of a gas turbine (such as combustor casing segments). The seal includes a cloth-layer assemblage positioned in the leakage-gap. The cloth-layer assemblage includes a metallic, woven cloth layer having a first group of generally equal-diameter warp wires and a second group of generally equal-diameter weft wires. Adjacent wires of one of the first and second groups of wires are spaced apart by a center-to-center distance equal to generally between four and ten times the diameter of the wires of the other of the first and second groups of wires.