Abstract: A nozzle for delivering a laser beam to a workpiece under water includes a hollow plenum having an axially spaced apart inlet and outlet, with a gas port disposed therebetween. The laser beam is delivered through the inlet and outlet toward a localized melting zone on the workpiece. A pressurized cover gas is delivered into the gas port for discharge through the outlet to cover the melting zone. The outlet is sized to discharge the gas as a jet for opposing pressure of the water to locally exclude the water at the melting zone.

Abstract: Ultrasound imaging of biological tissue using synthetic transmit focusing is performed by forming a combined echo signal at a target range from two transmit events: one with the focal point located at a depth less than the target range depth and the other with the focal point located at a depth greater than the target range depth. In the target range segment lying between the two focal points, the two echo signals are combined by applying weighting factors that are determined as a function of the target range location along the range segment defined by the two transmit focal points. A first weighting factor applied to a first echo signal derived from a first transmit focused at a first focal point has a maximum (i.e., unity) at the first focal point and decreases with increasing distance from the first focal point (decreasing to zero at the second focal point).

Abstract: A volumetric data set having a high intensity, dominant structure, near smaller, less intense structures is smoothed and segmented to separate the dominant structure. The dominant structure is masked out to result in the smaller, less intense structures which are displayed. For example, dominant structures such as the blood pool in atria, ventricles, and the aorta of a 3D angiography data set is segmented and removed from the data set using mathematical morphology operations to result in an enhanced data set. The enhanced data set is displayed by conventional means such as a maximum intensity projection (MIP) at different views to yield images of coronary arteries.

Abstract: A steam turbine having a shaft and a first (e.g., high-pressure) turbine section. A first embodiment also includes a first bearing longitudinally spaced apart from the first turbine section and further includes a first brush-seal assembly, having bristles, longitudinally positioned between the first turbine section and the first bearing and radially positioned proximate the shaft. The steam turbine is devoid of any backup seal to the bristles. In a second embodiment, a second brush seal assembly is positioned between the first and second (e.g., intermediate-pressure) turbine sections which lack any intervening bearing.

Abstract: Signal-to-noise ratio in synthetic transmit aperture imaging is significantly increased by encoding the transmit signals in orthogonal complementary codes for multiple point sources to be transmitted simultaneously. A number N of elements of a transducer array are simultaneously activated to transmit unfocused ultrasound waves during each one of N transmit events. For each transmit event, a different set of N code sequences is applied by a controller to N pulsers for the transducers to drive the transducers. The imaging depth is divided into several zones and code lengths are employed which increase with depth. A Hadamard construct of the orthogonal complementary sets, which requires only 2N correlations for decoding, is used.

Abstract: An optical element surface monitoring system includes an optical beam shaper and an optical sensor. The optical beam shaper directs an input beam of light from a laser source onto a surface portion of an optical element. The optical sensor receives a reflected beam of light from the optical element, derived from the input beam of light. The power of the reflected beam of light is monitored for an unexpected dropoff as an indicator of damage to the surface portion.

Abstract: Rotor temperature in induction motors is estimated without the need for any direct temperature sensors, by using only computer calculations based on data readily available in the motor control center. Thus for any given motor, it is generally possible to predetermine a relationship between rotor temperature and rotor resistance, so that by determining rotor resistance, rotor temperature can be calculated. Rotor resistance, in turn, can be calculated from measured information relating motor slip and motor torque. Any of several methods can be employed for determining torque and slip. Temperature estimation can be obtained by use of equivalent circuit methods, and additional relationships can be obtained from a simplified equivalent circuit.

Abstract: A superconductive magnet includes a superconductive coil assembly having a cryogenic vessel, a thermal shield enclosing the cryogenic vessel, and a vacuum enclosure enclosing the thermal shield. The cryogenic vessel, thermal shield and vacuum vessel have annular shells radially spaced apart from one another with reference to a common longitudinal axis and coaxially aligned with the common longitudinal axis. The magnet also includes a tube suspension assembly having a plurality of tubes located between respective ones of the cryogenic vessel, thermal shield and vacuum enclosure. The tubes are axially overlapped and are interconnected with one another and with the cryogenic vessel, thermal shield and vacuum enclosure. One tube has an end forming a sliding joint with the cryogenic vessel that allows both radial and axial movement of the cryogenic vessel relative to the thermal shield and vacuum enclosure during cooldown of the cryogenic vessel from ambient to cryogenic temperatures.

Abstract: A hybrid seal segment and a rotary machine (such as a steam or gas turbine) containing such hybrid seal segment. The machine has a rotor, a stator casing, and the hybrid seal segment. The annular hybrid seal segment has a circumferentially-extending channel between axially-spaced-apart first and second labyrinth-seal segments which are attached to a radially-outwardly located mounting block which is circumferentially offset from the labyrinth-seal segments. A brush-seal segment is positioned in the channel.

Abstract: A gas oven comprises at least a first burner element disposed within an oven cavity of the gas oven. A first control valve is disposed within a gas line connected to the burner element and to a gas source. The control valve controls gas flow to the burner element. A first temperature sensor is positioned so as to detect temperature about the burner element. A controller is electrically coupled to the temperature sensor and to the control valve wherein the controller ensures successful ignition of the burner element by monitoring the temperature signals generated from the temperature sensor to determine if the temperature signals increase a rate that is greater than a predetermined.

Abstract: A direct sequence spread spectrum receiver samples an incoming signal and stores the sample in memory. Power is then inhibited to the tuner of the receiver to minimize power consumption. The signal sample may be read from memory when necessary to process the signal without further signal acquisition. Power to other receiver sections may be selectively controlled to minimize power consumption. Such a receiver is useful in global positioning satellite (GPS) signal processing where the receiver has a limited power supply.

Abstract: A turbine assembly comprises a plurality of rotating blade portions in a spaced relation with a stationery shroud. The rotating blade portions comprise a root section, a tip portion and an airfoil. The tip portion has a pressure side wall and a suction side wall. A number of flow discouragers are disposed on the blade tip portion. In one embodiment, the flow discouragers extend circumferentially from the pressure side wall to the suction side wall so as to be aligned generally parallel to the direction of rotation. In an alternative embodiment, the flow discouragers extend circumferentially from the pressure side wall to the suction side wall so as to be aligned at an angle in the range between about 0.degree. to about 60.degree. with respect to a reference axis aligned generally parallel to the direction of rotation.

Abstract: A direct sequence spread spectrum architecture permits low power consumption during a synchronization phase of data reception by allowing the receiver to be turned off during most of the acquisition phase of reception, or by using a parallel correlator to keep acquisition time short. The architecture is particularly suitable for global positioning satellite (GPS) signal processing and permits multiple satellite codes and multiple Doppler bins to be searched either sequentially, without requiring the receiver to be turned on during the search process. The receiver output baseband data is sampled and stored over a time interval sufficient to achieve acquisition and synchronization for any one code division multiple access (CDMA) signal at any specific Doppler shift. This sample is digitally recorded and re-played from memory as many times as may be required to acquire and synchronize each desired CDMA signal. To keep processing energy consumption low, an analog (capacitor-based) cross-correlator is used.

Abstract: A permanent magnet motor employing sets of divided magnets on the surface of the rotor enables stator current to be used to control the net flux in the stator teeth, yoke and airgap. Each set of divided magnets circumscribes a respective portion of an arc of 360.degree. about the center of the rotor and is made up of a subset of a number of successive south (S) magnet polarities and a subset of an of successive north (N) magnet polarities arranged such that each subset about the 360.degree. arc is of opposite polarity to the adjacent subset at either side. This enables terminal voltage to be kept constant as speed increases, but with less current than in the case of conventional surface magnet motors.

Abstract: A method of hygroscopic optical material fabrication comprising the steps of cutting a hygroscopic optical material to generate an optical substrate of appropriate dimensions and polishing the hygroscopic optical material for appropriate surface figure or surface quality. The cutting and polishing of the hygroscopic optical material is completed while the hygroscopic optical material is isolated from aqueous contamination so as to maintain or increase the damage threshold of the hygroscopic optical material.

Abstract: A noise reducing clip device includes a clip body and a fulcrum-defining element. The clip body receives a washing machine wash tub wall and a fastener to secure the tub wall to the clip body and attach the clip body and tub wall therewith to a support leg disposed adjacent to the tub wall. The fulcrum-defining element is formed on and protrudes outwardly from the clip body for spacing the clip body from the support leg and providing only contact of the support leg with the fulcrum-defining element about which contact the support leg may undergo twisting and rocking motion induced by operation of a washing machine motor without imparting such motion to the tub wall via the clip body.

Abstract: A method for laser shock peening a target surface generates laser pulses from a cavity dumping oscillator having an optically-pumped laser and directs the pulses against the target. A first technique uses pulses having rectangular cross section. A second technique passes each generated pulse two or more times through the same optical amplifier before directing the pulse against the target. A third technique drives the laser with a time pulse of electric current having a rectangular shape. A reflective laser beam homogenizer uses two abutting mirrors to split a laser beam into two equal halves and then uses an odd number of additional mirrors to reflect each half first behind and then to the opposite one of the two mirrors to be reflected back as a beam having interchanged halves.

Abstract: An apparatus for applying heat to a rotatable workpiece is disclosed. A rotating lathe is provided for mounting a workpiece, for example a quartz tube, thereto so as to enable rotation of the workpiece. At least one translatable burner is coupled to a fuel source and an oxygen source for producing a flame. The burner is directed such that flame impinges upon the workpiece mounted on the rotating lathe. A first pulse control valve is coupled to and positioned between the translatable burner and the fuel source. A second pulse control valve is coupled to and positioned between the translatable burners and the oxygen course. The first and second pulse control valves are pulsed at a predetermined frequency to prevent the formation of a steady thermal boundary layer about the workpiece to improve the rate of heat transfer between the flame and the workpiece.

Abstract: A self-powered axial current sensor for generating a signal which accurately represents current in a power line includes, in one embodiment, a housing having a bus bar opening of substantially rectangular shape extending longitudinally therethrough. The housing also includes current sensor core retaining walls which define a current sensor region, and a cover base wall which defines, with one of the retaining walls, a power core region. A current sensor core and coil are located in the current sensor region and are positioned proximate the bus bar opening. The current sensor core and coil also are substantially symmetrical with respect to the center axis of the bus bar opening. The current sensor further includes a power core and a power coil located in the power core region and positioned substantially symmetrically with respect to the center axis of bus bar opening.

Abstract: A direct sequence spread spectrum receiver samples an incoming signal and stores the sample in memory. The signal sample is read from memory as necessary to process the signal without further signal acquisition. The correlator calculates an inner product by simultaneously correlating each bit of the sample with a corresponding bit of a replica signal. If the inner product does not exceed a threshold value the correlator calculates another inner product between the same signal sample and another replica signal. This occurs until all available signals are identified. In one embodiment, memory is segmented and each segment is read by a separate correlator allowing faster identification of one signal or multiple signals to be acquired simultaneously. Such a receiver is useful in global positioning satellite (GPS) signal processing where the incoming signal contains several satellite transmissions encoded with CDMA encoding.