Showing papers by "General Electric published in 1995"

Superconducting open-configuration MR imaging system for image-guided therapy.

Abstract: PURPOSE: To develop a superconducting magnetic resonance (MR) imager that provides direct access to the patient and permits interactive MR-guided interventional procedures. MATERIALS AND METHODS: A 0.5-T superconducting magnet that allows a region of vertical access to the patient was designed and constructed. This magnet was integrated with newly designed shielded gradient coils, flexible surface coils, and nonmagnetic displays and with position-monitoring probes and device-tracking instrumentation. RESULTS: The magnet homogeneity was 12.3 ppm, and the gradient field was linear to within 1% over an imaging region 30 cm in diameter. The signal-to-noise ratio was 10% higher than in a comparable 0.5-T superconducting imager. Images were obtained in several anatomic regions with use of routine pulse sequences. Interactive image plane selection and near real-time imaging, with use of fast gradient-recalled echo sequences, were demonstrated at a rate of one image every 1.5 seconds. CONCLUSION: MR-guided interv...

System and method for performing risk and credit analysis of financial service applications

Abstract: The present invention discloses a method and system for performing risk and credit analysis of financial service applications with a neural network. The neural network imitates and perfects a credit manager's evaluation and decision process to control loss and guide business expansion. In particular, the neural network screens applications to control loss and to find directions where business volume can increase with a minimum increase in loss. Initially, data variables are pre-processed and applied to the neural network. The neural network in the present invention is optimized by a non-iterative regression process, as opposed to the computationally intensive back propagation algorithm.

Display system for enhancing visualization of body structures during medical procedures

Abstract: An interactive display system superimposes images of internal structures on a semi-transparent screen through which a surgeon views a patient during a medical procedure. The superimposed image is derived from image data obtained with an imaging system. An invasive device is also tracked and displayed on the semi-transparent screen. A ray extending through the invasive device can also be displayed which shows the intended path of the invasive device. The image is registered with the surgeon's view of the patient and displayed in real-time during a medical procedure. This allows the surgeon to view internal and external structures, the relation between them, the proposed path of the invasive device, and adjust the procedure accordingly. A second embodiment employs stereoscopic viewing methods to provide three-dimensional representations of the radiological images superimposed on the semi-transparent screen through which the surgeon views the patient.

Imaging of interventional devices during medical procedures

Abstract: A tracking system monitors the position of a device within a subject and superimposes a graphic symbol on a diagnostic image of the subject. Registration of the tracked location with the diagnostic image is maintained in the presence of subject motion by monitoring subject motion and adjusting the display to compensate for subject motion. Motion monitoring can be performed with ultrasonic, optical or mechanical methods. The display can be adjusted by modifying the displayed location of the device or it can be adjusted by translating, rotating or distorting the diagnostic image.

Mobile tracking units employing motion sensors for reducing power consumption

Abstract: A mobile tracking unit capable of operating in a power-starved environment for a vehicle tracking system includes a navigation set for generating data corresponding to a respective vehicle position. The navigation set is periodically energized at a selected activation rate FG while the vehicle is moving to generate the vehicle position data. The tracking unit includes an electromagnetic emitter which is capable of transmitting the vehicle position data and which is periodically energized at a selected activation rate FEM while the vehicle is moving to transmit at least the vehicle position data. A motion sensor is employed for generating data indicative of vehicle motion. A tracking unit controller receives the vehicle motion data and controls the navigation set and the emitter based upon the vehicle motion data so that when the vehicle is stationary, each of activation rates FG and FEM can be respectively decreased by a predetermined factor, thus reducing the overall power consumption of the tracking unit. The tracking unit controller is further designed to return to activation rates FG and FEM upon the motion sensor sensing renewed vehicle motion, thus avoiding loss of vehicle position data during times of renewed vehicle motion.

Imaging of interventional devices in a non-stationary subject

Abstract: A tracking system monitors the position of a device within a subject and superimposes a graphic symbol on a diagnostic image of the subject. Registration of the tracked location with the diagnostic image is maintained in the presence of subject motion by monitoring subject motion and adjusting the display to compensate for subject motion. Motion monitoring can be performed with ultrasonic, optical or mechanical methods. The display can be adjusted by modifying the displayed location of the device or it can be adjusted by translating, rotating or distorting the diagnostic image.

Magnetic resonance devices suitable for both tracking and imaging

Abstract: A novel RF coil attached to an invasive device, such as a catheter, is used to detect magnetic resonance (MR) signals for monitoring the position of the device within a subject and for the acquisition of high-resolution magnetic resonance images of the tissue surrounding the device. The novel coil is sensitive to a small volume of MR active tissue during tracking procedures, but is sensitive to a larger volume during imaging procedures. During tracking, the MR signals are detected in the presence of magnetic field gradients and thus have frequencies which are substantially proportional to the location of the coil along the direction of the applied gradient. Signals are detected responsive to applied magnetic gradients to determine the position of the coil in several dimensions. The position of the novel coil, and hence the device, as determined by the tracking system is superimposed upon independently acquired medical diagnostic images. Magnetic Resonance images of the tissue surrounding the novel coil can be obtained by detecting the MR response signals from the novel coil using gradient-recalled, spin-echo or other MR imaging sequences.

Intermolecular vibrational coherence in molecular liquids

Abstract: The femtosecond optical heterodyne detected optical Kerr effect/Raman-induced Kerr effect (OHD OKE/RIKE) is described in detail with emphasis on the utility for investigating the intermolecular spectra and dynamics of liquids. The femtosecond dynamics of the liquids CS2, benzene and CCI4 are addressed through a combination of conventional time-domain kinetic and Fourier-transform analyses, and the physical origin of the intermolecular intensity is addressed for each. The distinctions between the excitation mechanisms of the femtosecond OKE/RIKE and other continuous-wave and picosecond Raman techniques are described. The distinctions between the dephasing mechanisms of intramolecular and intermolecular vibrational modes are discussed.

Automatically positioned focussed energy system guided by medical imaging

Abstract: An automatically positioned focussed energy transducer system facilitates medical procedures by allowing a physician to interactively view the position the focal point of a focussed energy transducer superimposed upon a medical image and computer generated model of internal structures of a patient. A tracking device tracks the position and orientation of the ultrasound transducer. A medical imaging system creates an image of internal structures of the patient near the location of the energy transducer. A general purpose computer either receives a model of internal structures constructed in advance, or employs a medical imaging device to create the model. The general purpose computer displays selected surfaces of the model in an orientation and view which coincides with the medical image acquired. A superposition device receives the position and orientation of the ultrasound transducer from the tracking device and superimposes a symbol on the images corresponding to the position of the energy transducer relative to the patient. The physician then selects an internal structure to be destroyed which the general purpose computer determines the locations which the focal point must scan in order to destroy the structure. An actuator, coupled to the general purpose computer causes the focal point of the energy transducer to scan these locations which the physician adjusts the intensity of energy provided to the focal point by an input device.

Layered minerals and compositions comprising the same

Abstract: Novel silicate minerals that have undergone a cation exhange with at least one heteroaromatic cation comprising a positively charged organo-substituted heteroatom and/or at least one positively charged heteroatom not part of an aromatic ring with at least one bond having a bond order greater than one and compositions comprising the same are described.

Investigation of the performance of the General Electric Advance positron emission tomograph in 3D mode

Abstract: Performance measurements of the General Electric Advance Positron Emission Tomograph operating with the septa retracted (3D mode) have been made. All reconstructions were done with the GE Advance 3D package. Performance tests were carried out with: the NEMA phantoms; a 3D Hoffman phantom; a Data Spectrum torso phantom with lung and cardiac inserts; and the "Utah" 3D evaluation phantom. Data collected included: transaxial and axial resolution, uniformity, recovery coefficients, count rate performance, dead time accuracy, and effect of scatter correction.

Integrated cranking inverter and boost converter for a series hybrid drive system

Abstract: An electric continuously variable drive system includes an ac motor, an alternator for supplying electrical power to the ac motor via a rectifier and an inverter, a heat engine for driving the alternator, an energy storage device for providing electrical energy to the electric continuously variable drive system, and a combination cranking inverter and boost converter. The combination cranking inverter and boost converter is coupled in series between the alternator and the energy storage device and coupled substantially in parallel with the rectifier in a series hybrid drive.

Turbine stator vane segments having combined air and steam cooling circuits

Abstract: Turbine stator vane segments have inner and outer walls with vanes extending therebetween. The inner and outer walls are compartmentalized and have impingement plates. Steam flowing into the outer wall passes through the impingement plate for impingement cooling of the outer wall surface. The spent impingement steam flows into cavities of the vane having inserts for impingement cooling the walls of the vane. The steam passes into the inner wall and through the impingement plate for impingement cooling of the inner wall surface and for return through return cavities having inserts for impingement cooling of the vane surfaces. The trailing edge is air-cooled.

Method for making a double-wall airfoil

Abstract: A method for making double-wall airfoil for applications such as the blades and vanes of gas turbine engines by depositing an airfoil skin over an inner support wall which is separately formed and contains channels filled by a channel filling means. The channel filling means is removed thereby forming integral channels within the double-wall for circulating a cooling gas adjacent to the airfoil skin. The airfoil skin deposited may be a metal alloy skin or a microlaminate structure, including microlaminate composite structures.

Laser shock peening for gas turbine engine vane repair

Abstract: A wide gap braze repair, particularly for a gas turbine engine vane or a component in the hot section of the engine. The repair is characterized by a braze filled void in a damaged area of the component, a laser shock peened surface over the repaired area of the braze filled void, and a region of deep compressive residual stresses imparted by laser shock peening (LSP) extending from the laser shock peened surface into the repair.

Double-wall airfoil

Abstract: A double-wall airfoil for applications such as the blades and vanes of gas turbine engines. The double-wall comprises an outer airfoil skin and an inner support wall that are metallurgically bonded to one another. The double-wall contains integral channels for passage of cooling air adjacent to the airfoil skin. Airfoil skin may be a metal alloy skin or a microlaminate structure, including microlaminate composite structures. Microlaminate composites typically have a lower density than that of the material used for the airfoil support wall, and a simplified internal geometry which promote weight reductions in the airfoils and increases in engine operating efficiency.

Fabrication and structures of two-sided molded circuit modules with flexible interconnect layers

Abstract: First and second flexible interconnect structures are provided and each includes a flexible interconnect layer and a chip with a surface having chip pads attached to the flexible interconnect layer. Molding material is inserted between the flexible interconnect layers for encapsulating the respective chips. Vias in the flexible interconnect layers are formed to extend to selected chip pads, and a pattern of electrical conductors is applied which extends over the flexible interconnect layers and into the vias to couple selected ones of the chip pads.

Closed circuit steam cooled bucket

Abstract: In a gas turbine bucket having a shank portion, a radial tip portion and an airfoil having leading and trailing edges and pressure and suction surfaces, and an internal fluid cooling circuit, an improvement wherein the internal fluid cooling circuit has a serpentine configuration including plural radial outflow passages and plural radial inflow passages. The radial outflow passages, in one example, are shaped to have aspect ratios of about 3.3 to 1 and Buoyancy Numbers of 0.80. A method of determining a configuration for steam cooling passages for a bucket stage in a gas turbine is also provided which includes, in one example, the steps of: a) determining combustion gas inlet temperature and mass flow rate of combustion gases passing through the gas turbine stage; b) taking into account Coriolis and buoyancy secondary flow effects in the steam coolant caused by rotation of the bucket stage; and c) configuring the radial outflow coolant passages to have a size and shape sufficient to produce aspect ratios of about 3.3 to 1 and Buoyancy Numbers in the radial outflow passages of 0.80.

Solidification processing of high temperature intermetallic eutectic-based alloys

Abstract: This paper describes the role of solidification processing of high-temperature eutectic alloys in the development of high-temperature structural materials. Particular emphasis is placed on directional solidification of eutectic-based alloys using cold crucible Czochralski crystal growth. Alloys with melting temperatures up to 2250 °C were directionally solidified by this technique for study of the microstructure, phase equilibria and mechanical properties. The attributes and limitations of the Czochralski technique are compared with those of other methods for solidification of high-temperature alloys. The microstructures and fracture toughness data of directionally solidified in situ composites generated from NbSi and CrNb alloy systems are presented. Property enhancements that can be achieved by directional solidification of high-temperature materials are discussed.

Intelligent battery charger for electric drive system batteries

Abstract: A battery charger connected to a source of substantially constant voltage power includes a regulator for conditioning the power for application to a battery to be charged. Net discharge current from the battery is monitored, as a function of time, during a time period between recharge cycles, and data representative of the net discharge current as a function of time is stored and used to compute net ampere-hour discharge data. The discharge data establish a total recharge ampere-hours to be applied to the battery, which corresponds to the net amount of discharge ampere-hours. The battery charger also compensates the total recharge ampere-hours by an amount determined from the age of the battery, and tracks the number of occurrences of recharge of the battery and the accumulated ampere-hours for applying an equalizing charge to the battery after a predetermined number of recharge occurrences and accumulated ampere-hours since a last equalizing charge. The charger further responds to battery temperature for adjusting the recharge constant voltage profile. The battery state of charge is computed from the monitored net ampere-hours of discharge current, and displayed. The battery may be the propulsion battery for an electric vehicle or for a hybrid vehicle which includes a combustion engine-driven generator to charge the battery.

Gas-path leakage seal for a gas turbine

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.

Compressor rotor cooling system for a gas turbine

Abstract: In a gas turbine including a compressor having a bore and a rotor comprised of multiple stages extending between a first stage at a forward end of the compressor and a last stage at an aft end of the compressor, each stage including a rotor disk having a peripheral rim and multiple blades secured to the peripheral rim, a combustion system comprising a plurality of combustors utilizing discharge air from the compressor for combustion, and multiple turbine stages driven by combustion gases from the combustion system, the improvement comprising means for supplying cooling air at least to a peripheral rim of the last stage of the compressor.

Serial bus control for appliances

Abstract: A household appliance having a serial bus control system includes a system controller, a plurality of slave nodes, and a serial bus connector. Each slave node is a sensor, an actuator, or the like, that is coupled to the serial bus connector and is responsive to a particular slave node address code generated by a master communications module that is part of the system controller. The serial bus connector is a loop of conductor which is attached at each end of the loop to the master communication module, with the slave nodes coupled to the loop at intermediate positions along the loop. The master communications module includes an interrogation circuit for generating digital transmissions to one or more of said slave node address codes and a receiver circuit for receipt of digital transmissions from the slave nodes coupled to said serial bus connector. The system controller further includes a processor for receiving sensor signals from slave nodes addressed by the communications module and for generating respective control signals to govern operation of actuators coupled to the serial bus connector.

A method for manufacturing polycarbonate

Abstract: The present invention provides a method for manufacturing polycarbonate with excellent dwell stability (e.g., thermal stability and hue stability) during melting and molding, as well as with a low content of impurities. The present invention further relates to a method for manufacturing polycarbonate wherein the molten polycarbonate is filtered through a passivation treated metal filter.

Removable inner turbine shell with bucket tip clearance control

Abstract: A turbine includes a plurality of inner shell sections mounting first and second stage nozzle and shroud portions. The inner shell sections are pinned to an outer containment shell formed of sections to preclude circumferential movement of the inner shell relative to the outer shell and enable thermal expansion and contraction of the inner shell relative to the outer shell. Positive bucket tip clearance control is afforded by passing a thermal medium about the inner shell in heat transfer relation with the shrouds about the first and second stage bucket tips, the thermal medium being provided from a source of heating/cooling fluid independent of the turbine. Access is provided to the rotor and turbine buckets by removing the outer and inner shell sections.

Characterization of the Oxide Film Formed on Type 316 Stainless Steel in 288°C Water in Cyclic Normal and Hydrogen Water Chemistries

Abstract: Characteristics of the oxide film formed on type 316 (UNS S31600) stainless steel (SS) in 288°C water under cyclic normal water chemistry (NWC) and hydrogen water chemistry (HWC) condition...

Thick thermal barrier coating having grooves for enhanced strain tolerance

Abstract: A thermal barrier coating is provided which is adapted to be formed on an article subjected to a hostile thermal environment while subjected to thermally, mechanically and/or dynamically-induced stresses, such as a component of a gas turbine engine. The thermal barrier coating is composed of a bond layer that tenaciously adheres an insulative ceramic layer to the article. The bond layer is formed of a metallic oxidation-resistant material, and has an average surface roughness Ra of at least about 7.5 micrometers, while the ceramic layer is characterized by being segmented by at least two sets of grooves. The grooves have substantially uniform widths of about 100 to about 500 micrometers, with adjacent grooves of each set being spaced about 10 to about 250 millimeters apart. The grooves promote the resistance of the thermal barrier coating to spalling, and are selectively located in the ceramic layer in order to tailor the stress relaxation capability of the thermal barrier coating to the size, geometry and service environment of the article. A preferred method for forming the grooves involves a liquid jet technique by which a portion of the ceramic layer is abraded by a high pressure liquid stream.

High inlet mach combustor for gas turbine engine

Abstract: A combustor for a gas turbine engine is disclosed which is able to operate efficiently at inlet air flows having a high subsonic Mach Number. The combustor has an outer liner and an inner liner spaced therefrom, wherein a combustion chamber is defined therebetween. A dome inlet module is provided which is in flow communication with compressed air flow from a compressor upstream thereof. The dome inlet module has an outer member fixed to the outer liner and an inner member fixed to the inner liner, wherein a flow passage is defined by the outer and inner members for the compressed air flow to flow freely from a compressor to the combustion chamber. Fuel atomizers are then utilized to inject fuel into the flow passage so that the fuel is mixed with the compressed air stream to form a fuel/air mixture which enters the combustion chamber.

Protection of thermal barrier coating by a sacrificial surface coating

Abstract: A method for protecting thermal barrier coatings deposited on engine parts from the deleterious effects of environmental contaminants at high temperatures is given. The method uses a sacrificially consumed oxide coating with the thermal barrier coating, where the consumption of the oxide coating increases the melting temperature of a contaminant composition above the surface temperature of the thermal barrier coating, or increases the viscosity of the contaminant composition to prevent its infiltration into the thermal barrier coating.

Method of fabricating a self-aligned DMOS transistor device using SiC and spacers

Abstract: A method for fabricating a semiconductor device includes patterning a refractory dielectric layer over a semiconductor layer of a first conductivity type; conformally depositing a first spacer layer over the patterned refractory dielectric layer and the semiconductor layer; patterning the first spacer layer to leave a first spacer adjacent to an edge of the patterned refractory dielectric layer; implanting ions of a second conductivity type to form a base region in the semiconductor layer; conformally depositing a second spacer layer over the patterned refractory dielectric layer and the semiconductor layer; patterning the second spacer layer to leave a second spacer adjacent to an edge of the first spacer; implanting ions of the first conductivity type to form a source region in the base region; removing the first and second spacers; applying a gate insulator layer over at least a portion of the semiconductor layer; conformally depositing a gate electrode layer over the gate insulator layer and the semiconductor layer; and patterning the gate electrode layer to form a gate electrode portion adjacent to an edge of the patterned refractory dielectric layer. Preferably the step of conformally depositing the gate electrode layer includes depositing an electrically conductive layer having the same thickness as a combined width of the first and second spacers. In one embodiment the semiconductor layer includes silicon carbide, the patterned refractory dielectric layer includes silicon dioxide, the spacers include silicon nitride, and the gate electrode layer includes polysilicon.