Abstract: Systems and methods are provided to enable a partial migration of applications from one database system to another without modifying the applications. In embodiments, a proxy server is configured to monitor the application's usage of a current database, and generate a migration plan to partially migrate database objects used by the application to a different type of database. An object may be selected for migration based on its usage level or its portability. After the partial migration, the proxy server may remain in place as a request router to route the application's requests to the two databases. In embodiments, the migration system may forward queries to both databases and compare the query results received from the two. Based on the comparison results, the migration system may programmatically determine adjustments to its query handling configuration settings.

Abstract: Airfoils for gas turbine engines are provided. In one embodiment, an airfoil formed from a ceramic matrix composite material includes opposite pressure and suction sides extending radially along a span and defining an outer surface of the airfoil. The airfoil also includes opposite leading and trailing edges extending radially along the span. The pressure and suction sides extend axially between the leading and trailing edges. The leading edge defines a forward end of the airfoil, and the trailing edge defining an aft end of the airfoil. Further, the airfoil includes a trailing edge portion defined adjacent the trailing edge at the aft end of the airfoil; a plenum defined within the airfoil forward of the trailing edge portion; and a cooling passage defined within the trailing edge portion proximate the suction side. Methods for forming airfoils for gas turbine engines also are provided.

Abstract: Airfoils for gas turbine engines are provided. In one embodiment, an airfoil formed from a ceramic matrix composite material includes opposite pressure and suction sides extending radially along a span and defining an outer surface of the airfoil. The airfoil also includes opposite leading and trailing edges extending radially along the span. The pressure and suction sides extend axially between the leading and trailing edges. The leading edge defines a forward end of the airfoil, and the trailing edge defining an aft end of the airfoil. Further, the airfoil includes a trailing edge portion defined adjacent the trailing edge at the aft end of the airfoil; a plenum defined within the airfoil forward of the trailing edge portion; and a cooling passage defined within the trailing edge portion proximate the suction side. Methods for forming airfoils for gas turbine engines also are provided.

Abstract: Airfoils for gas turbine engines are provided. In one embodiment, an airfoil formed from a ceramic matrix composite material includes opposite pressure and suction sides extending radially along a span and defining an outer surface of the airfoil. The airfoil also includes opposite leading and trailing edges extending radially along the span. The pressure and suction sides extend axially between the leading and trailing edges. The leading edge defines a forward end of the airfoil, and the trailing edge defining an aft end of the airfoil. Further, the airfoil includes a trailing edge portion defined adjacent the trailing edge at the aft end of the airfoil; a plenum defined within the airfoil forward of the trailing edge portion; and a cooling passage defined within the trailing edge portion proximate the suction side. Methods for forming airfoils for gas turbine engines also are provided.

Abstract: A modular pump platform includes a pump head module, a pump motor module, an electronics module and a separable tray. The pump motor module includes a pump motor having a rotary output removably coupled to a crank shaft of the pump head, the pump motor being one of multiple types of pump motors, and the pump motor module being detachably connected to the pump head module. The electronics module includes an electronic control circuit configured to control operation of the pump motor, the electronic control circuit being one of multiple types of electronic control circuits corresponding to the types of pump motors. Each of the pump head module, the pump motor module and the electronics module is detachably connected to the separable tray. At least the pump motor module is interchangeable with another pump motor module comprising a pump motor of another type.

Abstract: Parts of a pump head of a scroll pump facilitate an assembly process in which the stationary and orbiting scroll blades of the pump are angularly aligned or synchronized with one another. A metallic bellows of the pump head provides a primary means of synchronizing the stationary and orbiting scroll blades. The assembly process may be carried out using a fixture configured to be mountable to an assemblage including the bellows and the orbiting plate scroll. The fixture has a reference feature, and the orbiting plate scroll or the frame has another reference feature that can be aligned with the reference feature of the fixture, in the circumferential direction of the bellows, during the course of the assembly process.

Abstract: A rough vacuum pump system includes a primary vacuum pump and a secondary vacuum pump. The primary vacuum pump is an oil-free positive displacement pump, and has an inlet opening, an outlet opening, a compression stage between the inlet and outlet openings, and an intermediate gas passageway that connects to a gas flow path running through the compression stage. The secondary vacuum pump is connected to the intermediate gas passageway of the primary vacuum pump. The compression ratio of the primary and secondary vacuum pumps operating in combination is greater than that of the compression ratio of either of the primary and secondary vacuum pumps operating individually. A vacuum apparatus includes a tracer gas detector connected to an inlet of the primary vacuum pump.

Abstract: A vacuum pump isolation (VPI) valve is interposed between a vacuum pump and a vacuum chamber. During normal operation of the vacuum pump, the VPI valve is open, allowing fluid communication between the vacuum pump and the vacuum chamber. When the vacuum pump becomes non-operational such as by losing power, the VPI valve closes, thereby isolating the vacuum chamber from the vacuum pump. The closing of the VPI valve is driven by the exhaust gas pressure of the vacuum pump. The VPI valve becomes exposed to the exhaust gas pressure by the opening of a pilot valve, which may occur as a result of the vacuum pump ceasing to operate. By this configuration, the VPI valve is hermetic and does not require ambient air for its operation.

Abstract: A scroll pump has a tip seal between an axial end of the scroll blade of one of stationary and orbiting plate scrolls of the pump and the plate of the other of the stationary plate and orbiting plate scrolls. The scroll pump may have a ballast gas supply system and use the operation of the ballast gas supply system to assess the condition of the tip seal. Alternatively, the scroll pump may have two pressure sensors that sense pressure at two locations spaced along a compression mechanism of the pump to assess the condition of the tip seal.

Abstract: Airfoils for gas turbine engines are provided. In one embodiment, an airfoil formed from a ceramic matrix composite material includes opposite pressure and suction sides extending radially along a span and defining an outer surface of the airfoil. The airfoil also includes opposite leading and trailing edges extending radially along the span. The pressure and suction sides extend axially between the leading and trailing edges. The leading edge defines a forward end of the airfoil, and the trailing edge defining an aft end of the airfoil. Further, the airfoil includes a trailing edge portion defined adjacent the trailing edge at the aft end of the airfoil; a plenum defined within the airfoil forward of the trailing edge portion; and a cooling passage defined within the trailing edge portion proximate the suction side. Methods for forming airfoils for gas turbine engines also are provided.

Abstract: A filament assembly includes a core and a filament. At least a central portion of the filament is disposed on the core. At least the central portion may be straight or may have a high-resistance configuration such as one in which the filament follows a path that changes direction. A thermionically emissive layer may be disposed on the core so as to encapsulate at least the central portion. The filament assembly may be utilized in any application requiring the production of electrons.

Abstract: A vacuum scroll pump has a frame, a stationary plate scroll fixed to the frame, an orbiting plate scroll, an eccentric drive mechanism for driving the orbiting plate scroll, and counterbalancing features by which axial loads produced on the eccentric drive mechanism are offset. Scroll blades of the stationary and orbiting plate scrolls are nested to define pockets which constitute a compression stage between opposing front sides of plates of the stationary and orbiting plate scrolls. The counterbalancing features include an axial counterbalancing chamber defined at a back side of the plate of the orbiting plate scroll, i.e., opposite the side at which the compression stage is provided, and a mechanism by which an intermediate one of the pockets can be placed in communication with the counterbalancing chamber through the plate of the orbiting plate scroll.

Abstract: A rough vacuum pump system includes a primary vacuum pump and a secondary vacuum pump. The primary vacuum pump is an oil-free positive displacement pump, and has an inlet opening, an outlet opening, a compression stage between the inlet and outlet openings, and an intermediate gas passageway that connects to a gas flow path running through the compression stage. The secondary vacuum pump is connected to the intermediate gas passageway of the primary vacuum pump. The compression ratio of the primary and secondary vacuum pumps operating in combination is greater than that of the compression ratio of either of the primary and secondary vacuum pumps operating individually. A vacuum apparatus includes a tracer gas detector connected to an inlet of the primary vacuum pump.

Abstract: A scroll pump isolates vibrations of a pump head/motor assembly of the pump from the exterior of the pump and thus, suppresses the production of airborne noise. The pump includes a sound-muffling enclosure surrounding the pump head/motor assembly, feet supporting the enclosure, and elastic vibration isolators. The pump head/motor assembly is fixed to the tops of the vibration isolators, and the sound-muffling enclosure is fixed to the vibration isolators at the bottoms of the isolators. The scroll pump also has a locking system by which motion of the pump head/motor assembly relative to the sound-muffling enclosure can be limited or prevented, and by which the sound-muffling enclosure can be hard-mounted to a support surface independently of the feet.

Abstract: A scroll pump has a tip seal between an axial end of the scroll blade of one of stationary and orbiting plate scrolls of the pump and the plate of the other of the stationary plate and orbiting plate scrolls. The scroll pump may have a ballast gas supply system and use the operation of the ballast gas supply system to assess the condition of the tip seal. Alternatively, the scroll pump may have two pressure sensors that sense pressure at two locations spaced along a compression mechanism of the pump to assess the condition of the tip seal.

Abstract: Parts of a pump head of a scroll pump facilitate an assembly process in which the stationary and orbiting scroll blades of the pump are angularly aligned or synchronized with one another. A metallic bellows of the pump head provides a primary means of synchronizing the stationary and orbiting scroll blades. The assembly process may be carried out using a fixture configured to be mountable to an assemblage including the bellows and the orbiting plate scroll. The fixture has a reference feature, and the orbiting plate scroll or the frame has another reference feature that can be aligned with the reference feature of the fixture, in the circumferential direction of the bellows, during the course of the assembly process.

Abstract: A scroll pump has a tip seal between an axial end of the scroll blade of one of stationary and orbiting plate scrolls of the pump and the plate of the other of the stationary plate and orbiting plate scrolls. The scroll pump may have a ballast gas supply system and use the operation of the ballast gas supply system to assess the condition of the tip seal. Alternatively, the scroll pump may have two pressure sensors that sense pressure at two locations spaced along a compression mechanism of the pump to assess the condition of the tip seal.

Abstract: Parts of a pump head of a scroll pump facilitate an assembly process in which the stationary and orbiting scroll blades of the pump are angularly aligned or synchronized with one another. A metallic bellows of the pump head provides a primary means of synchronizing the stationary and orbiting scroll blades. The assembly process may be carried out using a fixture configured to be mountable to an assemblage including the bellows and the orbiting plate scroll. The fixture has a reference feature, and the orbiting plate scroll or the frame has another reference feature that can be aligned with the reference feature of the fixture, in the circumferential direction of the bellows, during the course of the assembly process.

Abstract: A vacuum scroll pump has a frame, a stationary plate scroll fixed to the frame, an orbiting plate scroll, an eccentric drive mechanism for driving the orbiting plate scroll, and counterbalancing features by which axial loads produced on the eccentric drive mechanism are offset. Scroll blades of the stationary and orbiting plate scrolls are nested to define pockets which constitute a compression stage between opposing front sides of plates of the stationary and orbiting plate scrolls. The counterbalancing features include an axial counterbalancing chamber defined at a back side of the plate of the orbiting plate scroll, i.e., opposite the side at which the compression stage is provided, and a mechanism by which an intermediate one of the pockets can be placed in communication with the counterbalancing chamber through the plate of the orbiting plate scroll.

Abstract: A scroll pump facilitates the installation of a new tip seal between an axial end of the scroll blade of one of inner stationary and orbiting plate scrolls of the pump and the plate of the other of the inner stationary plate and orbiting plate scrolls. To this end, the orbiting plate scroll has a central portion and an outer peripheral portion extending around and seated on the central portion. The outer peripheral portion of the orbiting plate scroll is keyed to and/or fastened to the central portion such that the outer peripheral portion is not rotatable relative to the central portion and yet is axially removable from the central portion. The tip seal can be readily accessed and replaced by removing the outer peripheral portion of the orbiting scroll plate from the central portion.