Abstract: A method of cooling a gas turbine engine case assembly includes moving a fan air valve that is operatively connected to a pre-cooler having a bypass inlet that is configured to receive bypass air that bypasses a gas turbine engine core to facilitate a provision of bypass air through a fan air valve inlet to the bypass inlet to a first open position, in response to a core compartment temperature being greater than a target core compartment temperature. The method further includes bleeding the bypass air through a bypass outlet of the pre-cooler into a core compartment.

Abstract: A method of cooling a gas turbine engine case assembly includes moving a fan air valve that is operatively connected to a pre-cooler having a bypass inlet that is configured to receive bypass air that bypasses a gas turbine engine core to facilitate a provision of bypass air through a fan air valve inlet to the bypass inlet to a first open position, in response to a core compartment temperature being greater than a target core compartment temperature. The method further includes bleeding the bypass air through a bypass outlet of the pre-cooler into a core compartment.

Abstract: A method of cooling a gas turbine engine case assembly includes moving a fan air valve that is operatively connected to a precooler having a bypass inlet that is configured to receive bypass air that bypasses a gas turbine engine core to facilitate a provision of bypass air through a fan air valve inlet to the bypass inlet to a first open position, in response to a core compartment temperature being greater than a target core compartment temperature. The method further includes bleeding the bypass air through a bypass outlet of the precooler into a core compartment.

Abstract: A method of cooling a gas turbine engine case assembly includes moving a fan air valve that is operatively connected to a pre-cooler having a bypass inlet that is configured to receive bypass air that bypasses a gas turbine engine core to facilitate a provision of bypass air through a fan air valve inlet to the bypass inlet to a first open position, in response to a core compartment temperature being greater than a target core compartment temperature. The method further includes bleeding the bypass air through a bypass outlet of the pre-cooler into a core compartment.

Abstract: A gas turbine engine includes a compressor section, a combustor in fluid communication with the compressor section, a turbine section in fluid communication with the combustor, and a bleed system that is configured to receive bleed air from the compressor section. The bleed system includes a first inlet duct coupled to an upstream location of the compressor section and a second inlet duct coupled to a downstream location of the compressor section. The first inlet duct and the second inlet duct merge into a common duct.

Abstract: The invention relates to methods for measuring unconjugated molecules, e.g. antibodies, in a mixture that also includes conjugated molecules, e.g. antibodies.

Abstract: A new method for immobilization of small molecules on solid supports via a macromolecular spacer has been developed. A protein or another macromolecule is first immobilized in an aqueous medium, and the solid support is than washed with an organic solvent. The small molecule is coupled in an organic medium, followed by organic medium washes. The new solid phases are useful for affinity purifications, immunoassays and other binding assays, and for selection of binders by panning procedures.

Abstract: Novel non-competitive assay techniques have been developed which not only improve sensitivity, but also are convenient and less susceptible to interfering factors. They are compatible with existing instruments and can be run in one or more test tubes. The analyte is reacted with labeled specific binder, after which the mixture is reacted with (1) an insoluble material attached to an analyte derivative and (2) a solid phase carrying a binder. The solid phase is then separated, and the label attached to the solid phase is measured. Variations of the procedure include the use of a reversible bridge for attaching the insoluble material to the analyte mimic and the conduct of the assay in various porous media, such as paper, chromatographic and electrophoretic media, and dipsticks.

Abstract: A novel non-competitive immunoassay technique has been developed which not only improves sensitivity, but also is convenient and less susceptible to interfering factors. It is compatible with existing instruments and is an assay that can be run in one test tube. The analyte is reacted with labeled specific binder, after which the mixture is reacted with (1) an insoluble material attached to an analyte derivative and (2) a solid phase carrying a binder. The solid phase is then separated, and the label attached to the solid phase is measured.

Abstract: This invention relates to methods that have been found useful in reducing non-specific binding in immunochemical assays, via methods that can be implemented much faster than those used by Ishikawa. The techniques include the use of a lipophilic bridge, such as a liposome, or the elution of the antigen-antibody complex from the solid phase by the use of an anti-idiotypic antibody or an antibody, or the use of a heterologous reversible bridge.

Abstract: A control system including a valve for controlling the flow of fuel to a burner, a resistive heater element connected between first and second terminals and disposed for igniting fuel emanating from the burner, an isolation transformer comprising a heater secondary winding connected to the first and second terminals so as to provide heating current to the heater element, and an electrode spaced from the heater element in a zone occupied by flame emanating from the burner. Also included is a start-up circuit for opening the valve to provide fuel to the burner for ignition by the heater element and a flame sensing circuit comprising an ac source, coupling means connecting the ac source means between the electrode and one of the first and second terminals with the secondary winding connected to the first and second terminals, and a detector circuit for detecting the flow between the electrode and the heater element of current conducted by flame in the zone.

Abstract: A laboratory gas burner and control apparatus including a burner assembly made from electrically conductive material and adapted for positioning on a counter. Defined by the burner is an inlet for connection to a gas source and an outlet for feeding gas to a flame. An electrically operated valve controls the flow of gas to the burner outlet and an igniter is energizable by a power supply to ignite gas emanating from the burner outlet. Associated with the igniter is an activation circuit that produces either ignition periods during which the igniter is energized by the supply or non-ignition periods during which the igniter is deenergized. Initiation of each ignition period requires manipulation of a manual activation mechanism. Once ignited, the presence of flame at the burner outlet is detected by a flame sensing mechanism. A valve control circuit maintains the supply valve open only during either ignition periods or periods during which flame is detected by the sensing mechanism.

Abstract: A fuel burner control system including a valve for controlling the flow of fuel to a burner, a resistive heater element for igniting fuel, a power supply for supplying current to the heater element, a flame sensing circuit comprising an ac source for supplying ac voltage to the heater element, and a detector for producing an output signal only in response to the flow through the heating element of current rectified by the flame, a valve control circuit for maintaining the valve open in response to the output signal, and a coupling circuit interconnecting the heating element with both the power supply and the sensing circuit and adapted to prevent the flow of current therebetween. By utilizing a coupling circuit that prevents the flow of current between the power supply and the flame sensing circuit, the resistive heater element can be efficiently and alternately used both as a fuel igniting mechanism and as an electrode for deriving current rectified by flame at the burner.

Abstract: An electrical control system including a source of electrical power and an electrical load coupled together by a power switch having alternate circuit open and circuit closed conditions. A closure means activates the power switch to a circuit closed condition to produce power transmission between the source and the load in response to a closure signal produced by a condition responsive control circuit. Connected in series with the power switch is a protective switch also activated from a circuit open to a circuit closed condition in response to the closure signal. A sensing circuit produces a fault signal in response to a closed condition of the power switch and a simultaneous circuit open condition of the protective switch.

Abstract: The invention is a fuel burner system including an electrical control circuit for initiating fuel flow to a burner in response to a call-for-heat from a condition responsive sensor, and an electrical ignitor for igniting the fuel emanating from the burner. Combustion or purging air is directed to the burner by a fan, the integrity of which is monitored by a sensor circuit that produces a fault signal in response to rotation of the fan at any speed in a given range of speeds. An inhibit circuit inhibits the control circuit to prevent opening of a fuel supply valve in response to the presence of the fault signal. Fan rotation at speeds either above or below a predetermined normal range indicates a malfunction and results in the fault signal that prevents the initiation of fuel flow and a try for ignition.

Abstract: A fuel burner control system including a valve for controlling the flow of fuel to a burner, a resistive heater element for igniting fuel, a power supply for supplying current to the heater element, a flame sensing circuit comprising an ac source for supplying ac voltage to the heater element, and a detector for producing an output signal only in response to the flow through the heating element of current rectified by the flame, a valve control circuit for maintaining the valve open in response to the output signal, and a coupling circuit interconnecting the heating element with both the power supply and the sensing circuit and adapted to prevent the flow of current therebetween. By utilizing a coupling circuit that prevents the flow of current between the power supply and the flame sensing circuit, the resistive heater element can be efficiently and alternately used both as a fuel igniting mechanism and as an electrode for deriving current rectified by flame at the burner.

Abstract: A burner control system including a valve for controlling the flow of fuel to a burner, a flame sensor for producing a flame signal in response to the presence of flame at the burner, a start-up circuit for producing a start-up signal, a control circuit for opening the valve to establish fuel flow in response to either the flame or start-up signal, and a timing capacitor first delays the generation of the start-up signal while charging during a predetermined purge period after energization of the start-up circuit and then terminates the start-up signal while discharging during a predetermined ignition period. A monostable electronic switch produces the start-up signal in response to the charge level on the timing capacitor and a valve initiator for opening the valve is powered by energy discharged by the timing capacitor during the ignition period.

Abstract: Disclosed herein is a fuel burner control system with a purge timer having a current responsive control relay that is energized into an active state only by a given minimum input current level but can be maintained in that active state by a substantially lesser input current level. After connection to an electrical supply an activating circuit supplies the given input current level to the control relay only after a predetermined purge time period established by an electrical timer, after which a hold circuit supplies the lesser input current level maintaining the relay in its active state. A blower dissipates any residual fuel vapor in the vicinity of the burner during the purge period and only after its conclusion is fuel flow initiated and ignition attempted in response to contact closures effected in the relay's active state.