Abstract: A synchronous commutation DC-DC converter comprises a current detection transformer (51) for detecting currents (IQ1, IQ2) flowing through the primary circuit, first and second DC bias power sources (53, 54) generating bias voltages (VBS1, VBS2) larger than the voltage corresponding to the exciting current of a transformer (4), and first and second comparators (55, 57) for driving first and second commutation MOS-FETs (7, 8) when the detection voltage (VDT) of a current detection resistor (52) exceeds the bias voltages (VBS1, VBS2) of the first and second DC bias power sources (53, 54). Since each commutation MOS-FET (7, 8) in the secondary circuit is driven in synchronism with the currents (IQ1, IQ2) of the primary circuit from which the exciting current component of the transformer (4) is removed, it is possible to minimize switching loss of each commutation MOS-FET (7, 8) in the secondary circuit and enhance conversion efficiency of the synchronous commutation DC-DC converter.

Abstract: A system has a number of parallel flowpath segments between a compressor and an evaporator. One or more valves selectively block and unblock at least one of the segments to provide capacity control.

Abstract: The invention detects gas turbine bleed valve position discordances. The invention derives a modified exhaust gas temperature derivative as the predictive criteria in conjunction with a control logic to determine bleed valve position discordances that may indicate a mechanical failure in a valve, or in the control means for a valve.

Abstract: A spallation resistant metallic article comprising a metallic substrate, at least one ceramic thermal barrier coating comprising a zirconia base and at least one other element selected from the group consisting of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc, In, Y, Mo and C, rare earth oxides, scandium, and indium, and a ceramic bond coat located on at least a portion of the substrate and between the metallic substrate and the at least one ceramic thermal barrier coating wherein the ceramic bond coat is composed of yttria stabilized zirconia (YSZ).

Abstract: A method for casting a cooled component includes molding a sacrificial pattern. A plurality of holes are formed through the pattern. A shell is formed over the pattern including filling the holes. The pattern is destructively removed from the shell. A metallic material is cast in the shell. The shell is destructively removed.

Abstract: A gas turbine engine rotor stack may be engineered or reengineered to include one or more longitudinally outwardly concave spacers. The spacers may provide a longitudinal compression force that increases with rotational speed.

Abstract: A cooled cast part has an exterior surface. A cooling passageway system extends from at least one inlet port to a plurality of outlet ports. The passageway system includes a first passageway to at least a first of the outlets and surrounding at least one post. The system includes a second passageway to at least a second of the outlets passing through the at least one post.

Abstract: A method for forming a component for use in a gas turbine engine, such as a turbine vane construction is provided. The method broadly comprises the steps of: forming a first aerodynamic structure having a first platform with a leading edge and a trailing edge, and an edge with an airfoil suction side structure; forming a second aerodynamic structure having a second platform with a leading edge and a trailing edge, and an first edge with an airfoil pressure side structure; and joining the two structures together so that the airfoil suction side structure mates with the airfoil pressure side structure to form an airfoil.

Abstract: An acoustic resonator for use in an engine is provided. The acoustic resonator includes a cavity having a volume, an aperture, and a passage connecting the aperture and the cavity. The aperture has a profiled surface for delaying separation of fluid entering the passage and for reducing losses caused by fluid separation.

Abstract: A compressor has a housing assembly and at least one rotor held by the housing assembly for rotation about a rotor axis. The rotor has a first face and a first housing element has a second face in facing spaced-apart relation to the first face of the rotor. One or more spacer elements are positioned from the first housing element. The spacer elements are machined. A coating is applied over the first surface around the one or more spacer elements.

Abstract: An arrangement for reducing soybean losses in soybean headers, includes a plurality of retainers which may be engaged to a tray edge and each retainer comprises a plate having a substantially planar central portion ending at a lower end which is curved downwardly forming a rounded flange from which a portion providing two grooves is projected, and arranged at a slightly offset angle with respect to the central portion and the upper end of which is folded upwardly at an angle of approximately 45° from the central portion.

Abstract: The disclosure relates to an arrangement in hearing protection, in the form of an acoustic headset, comprising a first auditory cup (10), a second auditory cup (11) and a stirrup or headband (12) interconnecting the auditory cups (10, 11), a microphone (13) being provided for receiving ambient sound and an electronic control unit (15) actuable by means of a button set (14) being provided for transmitting sound from the microphone (13) and a radio unit (16) by the intermediary of loudspeakers (17) in the auditory cups (10, 11). The button set (14) comprises a plurality of associated buttons (18, 18?, 19, 19?, 20, 20?, 21, 22) arranged in groups, and each group of buttons being disposed, for actuation by the wearer's fingers, in a separate depression or recess (23, 24, 25, 26) in the first auditory cup (10).

Abstract: Close to its front inner corner, each side plate is provided with an extension extending transversely inwards under the central plate and carrying a pivot member adapted to co-operate with a coaxial complementary pivot member fixed under the central plate, and in that each side plate is mounted to pivot about an axis that is common to the two pivot members, which axis is substantially perpendicular to the top surface of the central plate and arranged such that, in the pivoted position, each side plate is stowed substantially under the central plate. The system further advantageously comprising a device for causing each side plate to pivot relative to the central plate while the central plate is pivoting.

Abstract: A porous crystalline composition having a molar composition as follows: YO2:m X2O3:n ZO, wherein Y is a tetravalent element selected from the group consisting of silicon, germanium, tin, titanium and combinations thereof, X is a trivalent element selected from the group consisting of aluminum, gallium, boron, iron and combinations thereof, Z is a divalent element selected from the group consisting of magnesium, zinc, cobalt, manganese, nickel and combinations thereof, m is between about 0 and about 0.5, n is between about 0 and about 0.5; and the composition has an x-ray diffraction pattern which distinguishes it from the materials. A process for making the composition, and a process using the composition to treat an organic compound are also provided.

Abstract: A yarn comprising natural bamboo fiber and the method for producing the same is disclosed, wherein said yarn is prepared by spinning natural bamboo fibers alone or in combination with other fibers in a blended ratio of natural bamboo fibers comprising 30 to 100% by weight and other fibers comprising 70 to 0% by weight.

Abstract: A mixed-mode semiconductor memory includes a memory bank array, an analog/digital converter, a digital/analog converter, a plurality of digital buses and a control unit. The memory bank array includes a plurality of memory banks that are each composed of a plurality of pieces of single port memory. The analog/digital converter converts an input analog signal into digital information to store data corresponding to the input analog signal in the memory of the memory bank. The digital/analog converter converts a designated memory address of the memory bank into an analog signal to output the memory address in analog signal output form. The plurality of digital buses transmits the address and the digital information. The control unit sets the analog/digital converter and the digital/analog converter to store and output the digital information and the analog information and supplying an address signal to the memory bank.

Abstract: A collapsible boat hull comprises a pair of bottom panels and a pair of side panels, connected by continuous hinges. Erection of the boat causes a fore portion of the bottom panels to curve upwards, and fore portions of the side panels to curve inwards. The boat also includes a V-shaped rear seat, which acts to transfer force and vibration from a rearwardly mounted outboard motor to the side walls of the boat.