Abstract: An apparatus and/or system for an acoustically stable combustion chamber includes a combustion chamber with a geometry predetermined to shape resonant acoustic modes. The geometry diminishes coupling between resonant acoustic modes and driving mechanisms at a head portion and enhances coupling between resonant acoustic modes and damping mechanisms at an aft portion while meeting a predetermined stability level. The geometry diverges radially outward in an aftward direction at a divergence angle (AD) relative to a longitudinal axis, a diameter at the diverging portion is greater than at the injector end. An injector coupled at the head portion includes injector ports in a coplanar arrangement. The configuration of the injector ports alters the speed of sound profile of the combustion, drawing resonant acoustic modes towards the aft portion where the speed of sound is lower. Methods for simulating, designing, and using the acoustically stable combustion chamber are disclosed.

Abstract: A method comprising performing simulations to determine energy transfer between the bulk fluid motion of gases through a combustion chamber and resonant acoustic modes of the combustion chamber using a simulation model. The method also comprises configuring one or more combustion chamber parameters for the simulation model to shape the resonant acoustic modes to diminish coupling between the resonant acoustic modes and driving mechanisms at a head portion of the combustion chamber and to enhance coupling between the resonant acoustic modes and damping mechanisms at an aft portion of the combustion chamber. The method further comprises determining whether the combustion chamber meets a predetermined performance level in response to determining that the combustion chamber meets a predetermined combustion stability level.

Abstract: Disclosed herein is an apparatus. The apparatus comprises an injector coupled to a head portion of a combustion chamber, the injector comprising a plurality of injector elements distributed away from an inner annulus and in an outer annulus. A geometry of combustion chamber comprises a body portion, an optional shoulder portion, and a throat portion. An inner wall of combustion chamber converges radially inward towards the throat. The plurality of injector elements in combination with the geometry of the combustion chamber are configured to confine a predetermined percentage of mass flow associated with combustion to a predetermined outer annulus of the chamber.

Abstract: Disclosed herein is an apparatus. The apparatus comprises an injector coupled to a head portion of a combustion chamber, the injector comprising a plurality of injector elements distributed away from an inner annulus and in an outer annulus. A geometry of combustion chamber comprises a body portion, an optional shoulder portion, and a throat portion. An inner wall of combustion chamber converges radially inward towards the throat. The plurality of injector elements in combination with the geometry of the combustion chamber are configured to confine a predetermined percentage of mass flow associated with combustion to a predetermined outer annulus of the chamber.

Abstract: A protective apparatus includes a gemstone and a foreign material encapsulated and physically isolated within an interior space of the gemstone. The gemstone is one of a precious gemstone or a semi-precious gemstone or a semi-precious stone.

Abstract: A protective apparatus includes a gemstone and a foreign material encapsulated and physically isolated within an interior space of the gemstone. The gemstone is one of a precious gemstone or a semi-precious gemstone or a semi-precious stone.

Abstract: Disclosed herein is an apparatus. The apparatus comprises an injector coupled to a head portion of a combustion chamber, the injector comprising a plurality of injector elements distributed away from an inner annulus and in an outer annulus. A geometry of combustion chamber comprises a body portion, an optional shoulder portion, and a throat portion. An inner wall of combustion chamber converges radially inward towards the throat. The plurality of injector elements in combination with the geometry of the combustion chamber are configured to confine a predetermined percentage of mass flow associated with combustion to a predetermined outer annulus of the chamber.

Abstract: A method comprising performing simulations to determine energy transfer between the bulk fluid motion of gases through a combustion chamber and resonant acoustic modes of the combustion chamber using a simulation model. The method also comprises configuring one or more combustion chamber parameters for the simulation model to shape the resonant acoustic modes to diminish coupling between the resonant acoustic modes and driving mechanisms at a head portion of the combustion chamber and to enhance coupling between the resonant acoustic modes and damping mechanisms at an aft portion of the combustion chamber. The method further comprises determining whether the combustion chamber meets a predetermined performance level in response to determining that the combustion chamber meets a predetermined combustion stability level.

Abstract: A method comprising performing simulations to determine energy transfer between bulk fluid motion of gases through a combustion chamber and resonant acoustic modes of the combustion chamber using a simulation model. The method also comprises configuring one or more combustion chamber parameters for the simulation model to shape the resonant acoustic modes to diminish coupling between the resonant acoustic modes and driving mechanisms at a head portion of the combustion chamber and to enhance coupling between the resonant acoustic modes and damping mechanisms at an aft portion of the combustion chamber. The method further comprises determining whether the combustion chamber meets a predetermined performance level in response to determining that the combustion chamber meets a predetermined combustion stability level.

Abstract: A protective apparatus includes a gemstone and a foreign material encapsulated and physically isolated within an interior space of the gemstone. The gemstone is one of a precious gemstone or a semi-precious gemstone or a semi-precious stone.

Abstract: A protective apparatus includes a gemstone and a foreign material encapsulated and physically isolated within an interior space of the gemstone. The gemstone is one of a precious gemstone or a semi-precious gemstone or a semi-precious stone.

Abstract: A protective apparatus includes a gemstone and a foreign material encapsulated and physically isolated within an interior space of the gemstone. The gemstone is one of a precious gemstone or a semi-precious gemstone or a semi-precious stone.

Abstract: A method comprising performing simulations to determine energy transfer between bulk fluid motion of gases through a combustion chamber and resonant acoustic modes of the combustion chamber using a simulation model. The method also comprises configuring one or more combustion chamber parameters for the simulation model to shape the resonant acoustic modes to diminish coupling between the resonant acoustic modes and driving mechanisms at a head portion of the combustion chamber and to enhance coupling between the resonant acoustic modes and damping mechanisms at an aft portion of the combustion chamber. The method further comprises determining whether the combustion chamber meets a predetermined performance level in response to determining that the combustion chamber meets a predetermined combustion stability level.

Abstract: Disclosed herein are polyurethane elastomers and shaped articles prepared therefrom comprising charge-control agents to provide electrical conductivity to the elastomers, thereby allowing for their use in electrophotographic processes. The elastomers comprise a polyisocyanate prepolymer, a polyether prepolymer, and a hardener mixture comprised of at least one additional polyol and a charge-control agent. When used in an electrophotographic process, the elastomers are capable of exhibiting resistivities of less than 6×109 ohm-cm for 600,000 images or more.

Abstract: A method and system for deploying a spacecraft into a target orbit includes the use of controllable aerodynamic surfaces that can be deployed to facilitate a change in the inclination angle of the trajectory of the spacecraft. In a typical embodiment, the spacecraft includes an orbit transfer vehicle containing the aerodynamic structure, and a satellite that is to be placed into the target orbit. The spacecraft is launched to a higher-energy orbit than the target orbit, and the energy released by traveling to the target orbit is used to change the inclination angle. After entering a transfer orbit that includes a passage through the upper limits of the earth's atmosphere, the orbit transfer vehicle deploys the aerodynamic structure, and controls the aerodynamic surfaces of the structure to induce lift forces that alter its inclination angle each time the vehicle enters the atmosphere.

Abstract: The excess space and weight capacity of a conventional launch vehicle for a high-energy orbit, such as GEO, is used to deploy satellites to a low-energy orbit, such as LEO. In a preferred embodiment, an orbit-transfer vehicle provides the navigation, propulsion, and control systems required to transport a payload satellite from a high-energy-transfer orbit, such as GTO, to a predetermined low-energy orbit. Upon entering the low-energy orbit, the payload satellite is released from the orbit-transfer vehicle. To reduce the fuel requirements for this deployment via the orbit-transfer vehicle, a preferred embodiment includes aerobraking to bring the satellite into a low-earth orbit.

Abstract: An orbit-transfer vehicle provides the navigation, propulsion, and control systems required to transport a payload satellite from a geosynchronous-transfer orbit (GTO) to a predetermined low-earth orbit (LEO). Upon entering low-earth orbit, the payload satellite is deployed from the orbit-transfer vehicle. To reduce the cost and complexity of the payload satellite, the orbit-transfer vehicle is configured to provide common functional services, such as communications and power regulation, to the payload satellite during the transport, and/or after deployment. To reduce the fuel requirements for this deployment via the orbit-transfer vehicle, a preferred embodiment includes aerobraking to bring the satellite into a low-earth orbit.

Abstract: The excess space and weight capacity that is typical of a launch of large satellites to high-energy orbits, such as a geosynchronous orbit, is used to deploy small satellites at a substantially lower-energy orbit, such as a low-earth orbit. An orbit-transfer vehicle provides the navigation, propulsion, and control systems required to transport a payload satellite from a geosynchronous-transfer orbit (GTO) to a predetermined low-earth orbit (LEO). Depending upon the particular configuration, upon achieving the low-earth orbit, the orbit transfer vehicle either releases the payload satellite, or remains attached to the payload satellite to provide support services, such as power, communications, and navigation, to the payload satellite. To reduce the fuel requirements for this deployment via the orbit-transfer vehicle, the orbit-transfer vehicle employs aerobraking to bring the satellite into a low-earth orbit.

Abstract: The excess space and weight capacity of a conventional launch vehicle for a high-energy orbit, such as GEO, is used to deploy satellites to a low-energy orbit, such as LEO. In a preferred embodiment, an orbit-transfer vehicle provides the navigation, propulsion, and control systems required to transport a payload satellite from a high-energy-transfer orbit, such as GTO, to a predetermined low-energy orbit. Upon entering the low-energy orbit, the payload satellite is released from the orbit-transfer vehicle. To reduce the fuel requirements for this deployment via the orbit-transfer vehicle, a preferred embodiment includes aerobraking to bring the satellite into a low-earth orbit.

Abstract: The excess space and weight capacity that is typical of a launch of large satellites to high-energy orbits, such as a geosynchronous orbit, is used to deploy small satellites at a substantially lower-energy orbit, such as a low-earth orbit. An orbit-transfer vehicle provides the navigation, propulsion, and control systems required to transport a payload satellite from a geosynchronous-transfer orbit (GTO) to a predetermined low-earth orbit (LEO). Depending upon the particular configuration, upon achieving the low-earth orbit, the orbit transfer vehicle either releases the payload satellite, or remains attached to the payload satellite to provide support services, such as power, communications, and navigation, to the payload satellite. To reduce the fuel requirements for this deployment via the orbit-transfer vehicle, the orbit-transfer vehicle employs aerobraking to bring the satellite into a low-earth orbit.