Abstract: The present invention provides a helper cell for expressing an infectious, replication defective, alphavirus particle in an alphavirus-permissive cell. The helper cell includes (a) a first helper RNA encoding (i) at least one alphavirus structural protein, and (ii) not encoding at least one alphavirus structural protein; and (b) a second helper RNA separate from the first helper RNA, the second helper RNA (i) not encoding the alphavirus structural protein encoded by the first helper RNA, and (ii) encoding the at least alphavirus one structural protein not encoded by the first helper RNA, such that all of the alphavirus structural proteins assemble together into alphavirus particles in the cell. Preferably, the helper cell also includes a replicon RNA encoding an alphavirus packaging sequence and an inserted heterogeneous RNA.

Abstract: A method and apparatus are disclosed for coupling a multimode laser to a multimode fiber using a multimode tapered structure. The disclosed multimode tapered structure accepts an optical beam having a highly elliptical beam shape and converts the optical beam for acceptance by the circular multimode optical fiber. According to one aspect of the invention, the multimode tapered structure has a tapered form having an elliptical cross section at one end to match the rectangular laser aperture, and a circular cross section at the other end to match the fiber core. The disclosed multimode tapered structure is tapered from a smaller dimension at the input end that matches the dimension of the multimode light source to a larger dimension at the output end that matches the circular core of the multimode fiber. Depending on the selection of the numerical aperture and the length of the multimode tapered structure, coupling efficiencies up to 98 percent may be achieved with the present invention.

Abstract: The present invention provides a helper cell for expressing an infectious, replication defective, alphavirus particle in an alphavirus-permissive cell. The helper cell includes (a) a first helper RNA encoding (i) at least one alphavirus structural protein, and (ii) not encoding at least one alphavirus structural protein; and (b) a second helper RNA separate from the first helper RNA, the second helper RNA (i) not encoding the alphavirus structural protein encoded by the first helper RNA, and (ii) encoding the at least one alphavirus structural protein not encoded by the first helper RNA. Preferably, the helper cell is co-transfected with a replicon RNA encoding an alphavirus packaging segment and an inserted heterogeneous RNA, such that all of the alphavirus structural proteins assemble together into alphavirus particles in the cell, with said replicon RNA packaged therein.

Abstract: The present invention provides a helper cell for expressing an infectious, replication defective, alphavirus particle in an alphavirus-permissive cell. The helper cell includes (a) a first helper RNA encoding (i) at least one alphavirus structural protein, and (ii) not encoding at least one alphavirus structural protein; and (b) a second helper RNA separate from the first helper RNA, the second helper RNA (i) not encoding the alphavirus structural protein encoded by the first helper RNA, and (ii) encoding the at least alphavirus one structural protein not encoded by the first helper RNA, such that all of the alphavirus structural proteins assemble together into alphavirus particles in the cell. Preferably, the helper cell also includes a replicon RNA encoding an alphavirus packaging sequence and an inserted heterogeneous RNA.

Abstract: The present invention provides a helper cell for expressing an infectious, replication defective, alphavirus particle in an alphavirus-permissive cell. The helper cell includes (a) a first helper RNA encoding (i) at least one alphavirus structural protein, and (ii) not encoding at least one alphavirus structural protein; and (b) a second helper RNA separate from the first helper RNA, the second helper RNA (i) not encoding the alphavirus structural protein encoded by the first helper RNA, and (ii) encoding the at least one alphavirus structural protein not encoded by the first helper RNA. Preferably, the helper cell is co-transfected with a replicon RNA encoding an alphavirus packaging segment and an inserted heterogeneous RNA, such that all of the alphavirus structural proteins assemble together into alphavirus particles in the cell, with said replicon RNA packaged therein.

Abstract: The present invention provides a helper cell for expressing an infectious, replication defective, alphavirus particle in an alphavirus-permissive cell. The helper cell includes (a) a first helper RNA encoding (i) at least one alphavirus structural protein, and (ii) not encoding at least one alphavirus structural protein; and (b) a second helper RNA separate from the first helper RNA, the second helper RNA (i) not encoding the alphavirus structural protein encoded by the first helper RNA, and (ii) encoding the at least alphavirus one structural protein not encoded by the first helper RNA, such that all of the alphavirus structural proteins assemble together into alphavirus particles in the cell. Preferably, the helper cell also includes a replicon RNA encoding an alphavirus packaging sequence and an inserted heterogeneous RNA.

Abstract: The present invention provides a helper cell for expressing an infectious, replication defective, alphavirus particle in an alphavirus-permissive cell. The helper cell includes (a) a first helper RNA encoding (i) at least one alphavirus structural protein, and (ii) not encoding at least one alphavirus structural protein; and (b) a second helper RNA separate from the first helper RNA, the second helper RNA (i) not encoding the alphavirus structural protein encoded by the first helper RNA, and (ii) encoding the at least one alphavirus structural protein not encoded by the first helper RNA. Preferably, the helper cell is co-transfected with a replicon RNA encoding an alphavirus packaging segment and an inserted heterogeneous RNA, such that all of the alphavirus structural proteins assemble together into alphavirus particles in the cell, with said replicon RNA packaged therein.

Abstract: The present invention provides a helper cell for expressing an infectious, replication defective, alphavirus particle in an alphavirus-permissive cell. The helper cell includes (a) a first helper RNA encoding (i) at least one alphavirus structural protein, and (ii) not encoding at least one alphavirus structural protein; and (b) a second helper RNA separate from the first helper RNA, the second helper RNA (i) not encoding the alphavirus structural protein encoded by the first helper RNA, and (ii) encoding the at least one alphavirus structural protein not encoded by the first helper RNA. Preferably, the helper cell is co-transfected with a replicon RNA encoding an alphavirus packaging segment and an inserted heterogeneous RNA, such that all of the alphavirus structural proteins assemble together into alphavirus particles in the cell, with said replicon RNA packaged therein.

Abstract: The present invention provides a helper cell for expressing an infectious, replication defective, alphavirus particle in an alphavirus-permissive cell. The helper cell includes (a) a first helper RNA encoding (i) at least one alphavirus structural protein, and (ii) not encoding at least one alphavirus structural protein; and (b) a second helper RNA separate from the first helper RNA, the second helper RNA (i) not encoding the alphavirus structural protein encoded by the first helper RNA, and (ii) encoding the at least alphavirus one structural protein not encoded by the first helper RNA, such that all of the alphavirus structural proteins assemble together into alphavirus particles in the cell. Preferably, the helper cell also includes a replicon RNA encoding an alphavirus packaging sequence and an inserted heterogeneous RNA.

Abstract: A receiver system and method of operation are used to tune a selected channel from an input spectrum. The receiver includes an up-converter which responds to a selection setting for up-converting the input spectrum, including the selected channel and an unwanted spectrum; a first diplexer for dissipating the energy of the unwanted spectrum in a manner to reduce distortion effects on the up-converter; a down-converter for down-converting the up-converted selected channel having associated upper and lower sidebands and an intermediate frequency component; and a second diplexer for dissipating the energy of the upper and lower sidebands of the down-converted selected channel in a manner to improve intermodulation of the down-converter.

Abstract: The present invention provides a helper cell for expressing an infectious, replication defective, alphavirus particle in an alphavirus-permissive cell. The helper cell includes (a) a first helper RNA encoding (i) at least one alphavirus structural protein, and (ii) not encoding at least one alphavirus structural protein; and (b) a second helper RNA separate from the first helper RNA, the second helper RNA (i) not encoding the alphavirus structural protein encoded by the first helper RNA, and (ii) encoding the at least alphavirus one structural protein not encoded by the first helper RNA, such that all of the alphavirus structural proteins assemble together into alphavirus particles in the cell. Preferably, the helper cell also includes a replicon RNA encoding an alphavirus packaging sequence and an inserted heterogeneous RNA.

Abstract: Air flow cooling systems are used to increase component life. The present air flow cooling system increases the component life, increases efficiencies and eliminated components. For example, the power source or gas turbine engine is used to cause a flow of air around and about electrical components which need cooling. A plurality of compartments insure the direction of a flow of cooling air around and along the electrical components and the compressor section of the gas turbine engine causes the air to flow around and along the electrical components.

Abstract: Past methods and apparatus for manufacturing a rotor assembly have been used to provide rotor assemblies for rotating electric machines. Many of these electric machines rotate at low speeds. The present method and apparatus for manufacturing a rotor assembly can be used to make a rotor assembly to be used at high speeds. The rotor assembly includes a shaft having a frustoconical mounting surface defined thereon and having a plurality of magnets attached to the frustoconical mounting surface. A cover having a frustoconical inner surface surrounds the magnets and compressively secures the magnets to the shaft. The compressive forces applied by the cover and the adhesive used to secure the magnets insuring that a positive contact pressure exists between the magnets and the shaft during operation of the electric machine.

Abstract: Electric machines are used to produce electrical energy or are driven by electrical energy. Such machines include a stator assembly and a rotor assembly rotationally positioned within the stator assembly. A gap is formed between the rotating element and the stationary element. To increase the life and efficiency of many electric machines, heat formed within the gap is carried away by passing a cooling media through the gap. The present electric machine includes a cooling system wherein the electric machine is positioned in an inlet plenum of a gas turbine engine. Compressed air from the gas turbine engine is used to cool the gap of the electric machine. An expansion turbine is attached to the rotor assembly upstream of the gap and has high pressure gap cooling air directed through the expansion turbine into the gap to cool the electric machine.

Abstract: An electric vacuum valve comprising a body including a chamber having a first passage adapted to be connected to a source of vacuum, a valve seat in the chamber, a bi-metallic disc associated with the valve seat and operable to close the first passage and a second passage to the exterior of said body. A PTC disc is positioned in the chamber adjacent the bi-metallic disc and includes a first terminal connected to one side thereof and extending exteriorly of the body and a second terminal connected to the other side thereof and extending externally of the body such that heat from the PTC disc functions to radiate toward the bi-metallic disc when power is applied to said terminals to cause the bi-metallic disc to seat against the valve seat and when power is terminated, the bi-metallic disc cools and moves away from the valve seat.

Abstract: The problems of high cost, high loss and incomplete distortion compensation are resolved in a distortion generating circuit which employs a nonlinear phase modulator (70, FIG. 7) and a linear phase shifter (71) as a means of generating selected distortion signal components. The circuit includes an output coupler (30) and an output coupler (31) interconnected by means of a pair of wavepaths (32, 33). The nonlinear phase modulator (70), which includes a nonlinear reactive element (37), is disposed in one of the wavepaths (32). The linear phase shifter (71) is included in the other wavepath (33). By the appropriate adjustment of the linear phase shift in wavepath (33) the entire gamut of distortion characteristics can be compensated. Distortion generating circuits of the type disclosed can be employed as either predistorters or as postdistorters to compensate for the nonlinearities in electromagnetic signal devices, such as amplifiers.

Abstract: A complementary distortion circuit for reducing the level of IM products in the output of a TWT amplifier. One embodiment of the invention includes a 3 db, 90.degree. coupler to divide the input signal into two components of equal amplitude but differing phase with an IM generator positioned in the path of each component. The IM generator may comprise non-linear phase modulators or non-linear amplitude modulators. The two components are then re-combined in a second, 3 db, 90.degree. coupler. The non-linear phase-modulators may comprise varactors and the non-linear amplitude modulators may comprise varistors. The unit is intended to operate in the microwave region.

Abstract: A headlamp delay device comprising a switch having spaced contacts, a switch contact member movable to successively engage the contacts at different positions and detent means for holding the contact member in each of the positions. A housing has a piston and diaphragm dividing the housing into two chambers. A passage associated with one of the said chambers for connection to a source of vacuum and an inlet is provided to the one chamber. An orifice is associated with the inlet to the chamber for connection to a source of pressure higher than that supplied through the vacuum. A spring yieldingly urges the piston means in a direction opposite to that which the vacuum tends to move the piston. A shaft extends through the housing through the piston means and is connected to the switch contact member.

Abstract: A delay valve comprising a housing including a side wall and opposed end walls and a plug in the housing cooperating with the side wall to define a first and second chamber. A check valve is provided in the plug permitting flow of air in one direction such that air may flow freely from the second through said check valve to the first chamber and is prevented from flowing from the first to the second chamber. The end walls of the housing have openings communicating with the exterior of the housing, and the plug has a peripheral portion that cooperates with the side wall of the housing to define a helical passage communicating with said first and second chambers.

Abstract: A butterfly valve comprising a body having a cylindrical passage and a diametral pivot pin and a butterfly valve plate fixed to the pivot pin. The plate is formed with a planar central portion at which the pin is connected to the plate. In assembly, the pin is first placed in position and then the valve plate is adjusted angularly and radially until the periphery of the plate is in sealing relation to the inner surface of the passage. The plate is then fastened to the pin by welding.