Abstract: A valved conduit including a bioprosthetic valve, such as a heart valve, and a tubular conduit sealed with a bioresorbable material. The bioprosthetic heart valve includes prosthetic tissue that has been treated such that the tissue may be stored dry for extended periods without degradation of functionality of the valve. The bioprosthetic heart valve may have separate bovine pericardial leaflets or a whole porcine valve. The sealed conduit includes a tubular matrix impregnated with a bioresorbable medium such as gelatin or collagen. The valved conduit is stored dry in packaging in which a desiccant pouch is supplied having a capacity for absorbing moisture within the packaging limited to avoid drying the bioprosthetic tissue out beyond a point where its ability to function in the bioprosthetic heart valve is compromised. The heart valve may be sewn within the sealed conduit or coupled thereto with a snap-fit connection.

Abstract: A method and system of providing users with session-specific layouts during access of an application based on contextual data. The system identifies contextual data for each application access session and associates the contextual data with a particular in-app activity. The in-app activity corresponds to a task that is typically performed by the first user when the specific contextual data is detected. The contextual data can include location data, time and date data, and device type data.

Abstract: According to one implementation of the present disclosure, a method for determining airspeed for an unpowered vehicle is disclosed. The method includes: determining first and second body-fixed load factor measurements; determining a body Z-force coefficient based on an angle-of-attack parameter; and determining an airspeed value based on the second body-fixed load factor measurement and the body Z-force coefficient.

Abstract: One embodiment is an apparatus for inhibiting accidental contact by a human with a tail rotor connected to an empennage of an aircraft. The apparatus includes an inverted V-tail connected to an empennage of the aircraft forward of the tail rotor, the inverted V-tail stabilizer comprising a first V-tail stabilizer on a side of the empennage to which the tail rotor is connected and a second V-tail stabilizer on a side of the empennage opposite the side of the empennage to which the tail rotor is connected; and a shroud bar having a first end connected to an outboard end of the first V-tail stabilizer and a second end opposite the first end connected to the empennage aft of the tail rotor, wherein a horizontal distance from the shroud bar to the tail rotor is greater than a length of an arm of the human.

Abstract: According to one implementation of the present disclosure, a method for formation flight is disclosed. The method includes: during flight, arranging for a first aircraft to fly into a proximity range of a second aircraft; and determining first aircraft positioning based on power consumption data of the first aircraft, where the first aircraft positioning corresponds to power-reducing formation flight of the first aircraft.

Abstract: According to one implementation of the present disclosure, a method for determining angle-of-attack for an unpowered vehicle is disclosed. The method includes: determining a monotonic portion of a look-up curve of an angle-of-attack operating plot; during flight, determining, by an accelerometer disposed on the unpowered vehicle, first and second accelerometer outputs, where the first and second accelerometer outputs correspond to first and second body-fixed load factor measurements, respectively; determining an operating point on the monotonic portion by applying a quotient of the first and second accelerometer outputs to the angle-of-attack operating plot; and determining an angle-of-attack parameter corresponding to the determined operating point.

Abstract: One embodiment is an aircraft including a main body, a plurality of propulsion assemblies, and a plurality of hinges, wherein each of the plurality of propulsion assemblies is rotatably coupled to the main body using a hinge from the plurality of hinges. In an example, the aircraft includes four motor support arms and each motor support arm rotatably couples a specific propulsion assembly to a specific corresponding hinge on the main body of the aircraft and increases a span of the aircraft when the aircraft is in the flight configuration and reduces the footprint of the aircraft when the aircraft is in a storage configuration.

Abstract: A soft actuator, comprising: a deformable member having a base stiffness; one or more electroadhesive (EA) clutches, the one or more EA clutches being in mechanical communication with the deformable member, and the one or more EA clutches being configured to, when actuated, give rise to a region of relative stiffness within the actuator that is greater than the base stiffness. A method, comprising: in a soft actuator, actuating one or more EA clutches in mechanical communication with a deformable member having a base stiffness, the actuating being performed so as to give rise to one or more regions of relative stiffness within the soft actuator that is greater than the base stiffness; and effecting a bending force within the deformable member such that the deformable member attains a shape, the shape at least partially defined by the actuated one or more EA clutches.

Abstract: An example non-transitory machine-readable medium includes instructions to capture a first image of a scene that includes light emitted by a display device, change a brightness of the display device, capture a second image of the scene while the brightness of the display device is changed, train a machine-learning model with the first image and the second image to provide a filter to reduce glare, and apply the machine-learning model to a third image captured of the scene to reduce glare in the third image, which is different from the first and second images.

Abstract: A technique facilitates tracking and assessing a fatigue life of a tubing string utilizing, for example, estimation of cycles to failure when used in a wellbore operation. The technique may comprise initially determining a fatigue life of a tubing string. Additionally, the technique comprises utilizing a sensing device, e.g. a magnetic flux leakage (MFL) device, to monitor the tubing string. When an anomaly, e.g. a new defect, is detected by the sensing device, a new fatigue life of the tubing string is determined based on the change. The new fatigue life may be used to estimate a fatigue life in terms of cycles to failure.

Abstract: An unmanned rotorcraft includes an airframe, rotor blades that are coupled to the airframe for rotation therewith, a propulsion unit having a propeller, and an actuator that is coupled to the airframe and adapted to temporarily reorient the propulsion unit such that an axis of the propeller moves out of alignment with an axis of the rotor blades. Rotation of the propeller causes counter-rotation of the airframe and rotor blades. The rotor blades and blades of the propeller are adapted to deploy from collapsed positions when flight of the rotorcraft is initiated. A method of operation by the rotorcraft includes, when it is determined that a current heading does not correspond to a determined flight path, causing the actuator to temporarily reorient the propulsion unit in accordance with an angular orientation of the actuator relative to the current heading.

Abstract: A system can include a flight controller for an aircraft that includes an electric motor that drives blades with a variable pitch, where the flight controller receives a command to change a flight characteristic of the aircraft and creates a torque command and a revolutions per minute (RPM) command. The system can also include a propulsion assembly, where the propulsion assembly creates a current command based at least in part on the torque command and the RPM command, creates a blade pitch command based at least in part on the torque command and the RPM command, communicates the current command to the electric motor to change a mechanical output of the electric motor, and communicates the blade pitch command to blade actuators to control the pitch of the blades. The current command and the blade pitch command cause the blades of the aircraft to rotate at a predetermined RPM.

Abstract: A technique facilitates tracking and assessing a fatigue life of a tubing string utilizing, for example, estimation of cycles to failure when used in a wellbore operation. The technique may comprise initially determining a fatigue life of a tubing string. Additionally, the technique comprises utilizing a sensing device, e.g. a magnetic flux leakage (MFL) device, to monitor the tubing string. When an anomaly, e.g. a new defect, is detected by the sensing device, a new fatigue life of the tubing string is determined based on the change. The new fatigue life may be used to estimate a fatigue life in terms of cycles to failure.

Abstract: A tiltrotor aircraft has a vertical takeoff and landing flight mode and a forward flight mode. The aircraft includes an airframe having at least one wing. First and second oppositely disposed booms extend longitudinally from the at least one wing. Forward rotors are coupled to the forward ends of the booms and aft rotors are coupled to the aft ends of the booms. The forward rotors are reversibly tiltable between a vertical lift orientation, wherein the forward rotors are above the booms, and a forward thrust orientation, wherein the forward rotors are forward of the booms. The aft rotors are reversibly tiltable between a vertical lift orientation, wherein the aft rotors are below the booms, and a forward thrust orientation, wherein the aft rotors are aft of the booms.

Abstract: One embodiment is an aircraft including a fuselage; a wing connected to the fuselage; first and second booms connected to the wing on opposite sides of the fuselage; first and second forward propulsion systems attached to forward ends of the first and second booms; first and second aft propulsion systems fixedly attached proximate aft ends of the first and second booms; and first and second wing-mounted propulsion systems connected to outboard ends of wings; wherein the first and second wing-mounted propulsion systems are tiltable between a first position when the aircraft is in a hover mode and a second position when the aircraft is in a cruise mode.

Abstract: A method of autonomous flight path planning for a group of cooperating aircraft operating in formation includes: receiving information related to obstructions that interfere with an aircraft of the group continuing on a flight path; calculating a velocity obstacle for each obstruction; calculating a plurality of candidate velocities outside of the velocity obstacles; selecting a first velocity from the candidate velocities and operating a leader of the group at the first velocity; calculating, based upon keeping a follower aircraft in formation, a second velocity for the follower; determining whether the second velocity is inside one of the velocity obstacles; operating the follower at the second velocity when the second velocity is outside the velocity obstacles; and calculating a revised velocity that is outside of the velocity obstacles and operating the follower at the revised velocity when the second velocity is inside one of the velocity obstacles.

Abstract: A tiltrotor aircraft has a vertical takeoff and landing flight mode and a forward flight mode. The aircraft includes an airframe having at least one wing. First and second oppositely disposed booms extend longitudinally from the at least one wing. Forward rotors are coupled to the forward ends of the booms and aft rotors are coupled to the aft ends of the booms. The forward rotors are reversibly tiltable between a vertical lift orientation, wherein the forward rotors are above the booms, and a forward thrust orientation, wherein the forward rotors are forward of the booms. The aft rotors are reversibly tiltable between a vertical lift orientation, wherein the aft rotors are below the booms, and a forward thrust orientation, wherein the aft rotors are aft of the booms.

Abstract: A ducted-rotor aircraft may include a fuselage and first and second ducts that are coupled to the fuselage at respective first and second locations. The first location may be on a first side of a fuselage of the aircraft and spaced from a nominal yaw axis of the aircraft. The second location may be on an opposed second side of the fuselage and spaced from the nominal yaw axis. Each duct may include a rotor that is disposed in an opening that extends through the duct. Each rotor may include a plurality of blades. Each duct may further include a control vane that is mounted aft of the plurality of blades and that is pivotable about a vane axis that is oriented toward the nominal yaw axis.

Abstract: One embodiment is an aircraft including a main body, a plurality of propulsion assemblies, and a plurality of hinges, wherein each of the plurality of propulsion assemblies is rotatably coupled to the main body using a hinge from the plurality of hinges. In an example, the aircraft includes four motor support arms and each motor support arm rotatably couples a specific propulsion assembly to a specific corresponding hinge on the main body of the aircraft and increases a span of the aircraft when the aircraft is in the flight configuration and reduces the footprint of the aircraft when the aircraft is in a storage configuration.

Abstract: According to one implementation of the present disclosure, a method for determining airspeed for an unpowered vehicle is disclosed. The method includes: determining first and second body-fixed load factor measurements; determining a body Z-force coefficient based on an angle-of-attack parameter; and determining an airspeed value based on the second body-fixed load factor measurement and the body Z-force coefficient.