Abstract: A constant density heat exchanger and method of operating are provided. The constant density heat exchanger includes a housing extending between a first end and a second end and defining a chamber having an inlet and an outlet. A first plate is positioned at the first end of the housing and rotatable about an axis of rotation such that the first plate selectively allows a working fluid to flow into the inlet of the chamber. A second plate is positioned at the second end of the housing and rotatable about the axis of rotation such that the second plate selectively allows the working fluid to flow out of the outlet of the chamber. The first plate and the second plate are rotatable about the axis of rotation so as to hold a volume of the working fluid at constant density as a heat source imparts thermal energy thereto.

Abstract: A mounting device may include a top plate including a cone-shaped center portion, a flange coupled to the cone-shaped center portion, a number of apertures defined in the flange, and a number of fasteners engaged with the apertures to couple the top plate to a surface of a structure. The flange seals a bottom side of the top plate to the surface of the structure. The flange includes a seal coupled to the bottom of the flange. The cone-shaped center portion has a convex paraboloid shape. The flange includes at least one surface that is parallel to a surface of the structure, and a transition between the cone-shaped center portion and the flange forms an angle. The top plate has a diameter sufficient to displace a load greater than 50 pounds over the surface of the structure.

Abstract: A vehicle detection system warns snowmobilers of other approaching vehicles with potential risk of collision. To better prevent accidents, the system calculates collision risks and warns the rider based on level of risk. When riding in groups, a member can press a stop request button to ask the group to slow down. When a member exits the group, everyone in the group will receive a message, alerts or indication with the update. The vehicle detection system utilizes Bluetooth® low energy (BLE), LoRaWAN® technologies and/or global positioning system technologies and is designed to detect other devices in the region and use acquired information to calculate proximity and risk of collision.

Abstract: A weapon is capable of firing cased telescoped (CT) ammunition rounds. The weapon includes a barrel, a chamber member that defines a chamber configured to hold a CT round for firing from the weapon, a non-rotating carrier body, and linkage. The linkage is constructed and arranged to move the chamber member (i) from a firing position in which the chamber member is aligned with the barrel for firing the CT round to an ejection/loading position in which the chamber member is not aligned with the barrel for ejecting a spent CT round and receiving a next CT round in response to the non-rotating carrier body moving away from the barrel, and (ii) from the ejection/loading position to the firing position in response to the non-rotating carrier body moving toward the barrel.

Abstract: Disclosed herein are recombinant spider silk compositions formed from a stable powder as it hydrates, cleanses, defends, detoxifies, mattifies, and/or exfoliates the skin, among other uses.

Abstract: A monolithic heat exchanger body for inputting heat to a closed-cycle engine includes heating walls and heat sink, such as heat transfer regions. The heating walls are configured and arranged in an array of spirals or spiral arcs relative to a longitudinal axis of an inlet plenum. Adjacent portions of the heating walls respectively define corresponding heating fluid pathways fluidly communicating with the inlet plenum. At least a portion of the heat sink is disposed about at least a portion of the monolithic heat exchanger body. The heat sink includes working-fluid bodies including working-fluid pathways that have a heat transfer relationship with the heating fluid pathways. Respective ones of the heat transfer regions have a heat transfer relationship with a corresponding semiannular portion of the heating fluid pathways. Respective ones of the heat transfer regions include working-fluid pathways fluidly communicating between a heat input region and a heat extraction region.

Abstract: In embodiments, an additive manufacturing apparatus comprises a chassis assembly and a skin at least partially covering the chassis assembly. The chassis assembly comprises a lower chassis section secured to a low voltage chassis section; an upper environmental chassis section secured to and extending over the low voltage chassis section and the lower chassis section; a high voltage chassis section secured to the upper environmental chassis section and the lower chassis section; and a build receptacle carriage adjustably coupled to the lower chassis section. The skin comprises first and second doors providing access to the low voltage chassis section and the high voltage chassis section; a rear panel providing access to the upper environmental chassis section; a top panel covering a top of the upper environmental chassis section; and at least one hinged door providing access to the lower chassis section.

Abstract: A system includes a supply receptacle defining one or more supply receptacle sidewalls and an upwardly-facing receptacle opening, a piston positioned at least partially within the supply receptacle, where the piston, the upwardly-facing receptacle opening, and the one or more supply receptacle sidewalls at least partially define an interior space of the supply receptacle, and the piston is positionable between an extended position, in which the interior space has an extended volume, and a retracted position, in which the interior space has a retracted volume that is greater than the extended volume, and a dosing hopper positioned above and in selective communication with the interior space of the supply receptacle, where the dosing hopper is structurally configured to deliver build material to the interior space.

Abstract: An engine body may include a piston body comprising a piston chamber and a regenerator body comprising a regenerator conduit. An engine body may include a working-fluid heat exchanger body comprising a plurality of working-fluid pathways fluidly communicating between the piston chamber and the regenerator conduit. Additionally, or alternatively, an engine body may include a heater body comprising a plurality of heating fluid pathways and the plurality of working-fluid pathways. The heating fluid pathways may have a heat transfer relationship with the working fluid pathways. The working-fluid pathways may fluidly communicate between the piston chamber and the regenerator conduit. The engine body may include a monolithic body defined at least in part by the piston body, the regenerator body, and the working-fluid heat exchanger body, and/or defined at least in part by the piston body, the regenerator body, and the heater body.

Abstract: A constant density heat exchanger and system for energy conversion is provided. The constant density heat exchanger includes a housing extending between a first end and a second end and defining a chamber having an inlet and an outlet. A first flow control device is positioned at the inlet of the chamber and movable between an open position in which a working fluid is permitted into the chamber and a closed position in which the working fluid is prevented from entering the chamber. A second flow control device is positioned at the outlet of the chamber and movable between an open position in which the working fluid is permitted to exit the chamber and a closed position in which the working fluid is prevented from exiting the chamber. A heat exchange fluid imparts thermal energy to the volume of working fluid as the first flow control device and the second flow control device hold the volume of working fluid at constant density within the chamber.

Abstract: A method of manufacturing a green body part comprises depositing a layer of a powder on a working surface; and selectively depositing a binder solution comprising a thermoplastic binder, a fluorescent material, and a binder medium into the layer of powder in a pattern representative of a structure of a layer of the green body part. The thermoplastic binder comprises one or more polymer strands dissolved in a solvent medium having an average molecular weight from greater than or equal to 7,000 g/mol to less than or equal to 100,000 g/mol. Binder solutions comprising fluorescent material and green body parts adhered together using the same are also disclosed.

Abstract: A piston apparatus includes a plurality of piston assemblies respectively having a first piston body and a first piston disposed within a first volume defined by the first piston body, a second piston body and a second piston disposed within a second volume defined by the second piston body, and a connection member coupled to the first piston and the second piston. The first and second volume respectively include an expansion chamber and a compression chamber defined by opposite sides of the corresponding piston. The respective expansion chambers fluidly communicate with a corresponding compression chamber of another one of the piston assemblies. The first volume of a first piston assembly fluidly communicates with the first volume and the second volume of a second piston assembly, and the first volume of a third piston assembly fluidly communicate with the first volume and the second volume of the second piston assembly.

Abstract: An energy conversion apparatus may include an engine assembly, such as a monolithic engine assembly. The engine assembly may include a first monolithic body segment and a plurality of second monolithic body segments directly coupled or directly couplable to the first monolithic body segment. The first monolithic body segment may define a combustion chamber and a recirculation pathway in fluid communication with the combustion chamber. The recirculation pathway may be configured to recirculate combustion gas through the combustion chamber. The plurality of second monolithic body segments may respectively define at least a portion of a piston chamber and a plurality of working-fluid pathways fluidly communicating with the piston chamber.

Abstract: A constant density heat exchanger is provided. The constant density heat exchanger includes a housing extending between a first end and a second end and defining a chamber having an inlet and an outlet. A first flow control device is positioned at the inlet of the chamber and movable between an open position in which a working fluid is permitted into the chamber and a closed position in which the working fluid is prevented from entering the chamber. A second flow control device is positioned at the outlet of the chamber and movable between an open position in which the working fluid is permitted to exit the chamber and a closed position in which the working fluid is prevented from exiting the chamber. A heat exchange fluid imparts thermal energy to the volume of working fluid held at constant density within the chamber by the first and second control devices.

Abstract: A binder comprises a monomer and an initiator. The monomer comprises at least one of a difunctional monomer and a monofunctional monomer. A method of manufacturing a part includes depositing a layer of particulate material on a working surface; selectively applying a binder in at least one of an edge of the layer of particulate material and an infill pattern representative of a stress of the object; repeating the steps of depositing and selectively applying to form a plurality of layers of particulate material with the applied binder; and exposing the plurality of layers of particulate material with the applied binder to an excitation source to decompose the initiator and initiate polymerization of the monomer to thereby form the green body part.

Abstract: An irradiation device for additively manufacturing three-dimensional objects may include a beam generation device configured to generate an energy beam, an optical modulator including a micromirror array disposed downstream from the beam generation device, and a focusing lens assembly disposed downstream from the optical modulator. The micromirror array may include a plurality of micromirror elements configured to reflect a corresponding plurality of beam segment of the energy beam along a beam path incident upon the focusing lens assembly. The focusing lens assembly may include one or more lenses configured to focus the plurality of beam segments such that for respective ones of a plurality of modulation groups including a subset of micromirror elements, a corresponding subset of beam segments are focused to at least partially overlap with one another at a combination zone corresponding to the respective modulation group.

Abstract: Provided herein are mycelium materials and methods for production thereof. In some embodiments, a mycelium material includes: a cultivated mycelium material including one or more masses of branching hyphae, wherein the one or more masses of branching hyphae may be disrupted and/or a bonding agent may be combined with the cultivated mycelium material. Methods of producing a mycelium material are also provided.

Abstract: An irradiation device for additively manufacturing three-dimensional objects may include a beam generation device configured to generate an energy beam, an optical modulator including a micromirror array disposed downstream from the beam generation device, and a focusing lens assembly disposed downstream from the optical modulator. The micromirror array may include a plurality of micromirror elements configured to reflect a corresponding plurality of beam segment of the energy beam along a beam path incident upon the focusing lens assembly. The focusing lens assembly may include one or more lenses configured to focus the plurality of beam segments such that for respective ones of a plurality of modulation groups including a subset of micromirror elements, a corresponding subset of beam segments are focused to at least partially overlap with one another at a combination zone corresponding to the respective modulation group.

Abstract: An irradiation device for additively manufacturing three-dimensional objects may include a beam generation device configured to generate an energy beam, an optical modulator including a micromirror array disposed downstream from the beam generation device, and a focusing lens assembly disposed downstream from the optical modulator. The micromirror array may include a plurality of micromirror elements configured to reflect a corresponding plurality of beam segment of the energy beam along a beam path incident upon the focusing lens assembly. The focusing lens assembly may include one or more lenses configured to focus the plurality of beam segments such that for respective ones of a plurality of modulation groups including a subset of micromirror elements, a corresponding subset of beam segments are focused to at least partially overlap with one another at a combination zone corresponding to the respective modulation group.

Abstract: A piston apparatus may include a plurality of piston assemblies respectively having a first piston body and a first piston disposed within a first volume defined by the first piston body, a second piston body and a second piston disposed within a second volume defined by the second piston body, and a connection member coupled to the first piston and the second piston. The first and second volume may respectively include an expansion chamber and a compression chamber defined by opposite sides of the corresponding piston. The respective expansion chambers may fluidly communicate with a corresponding compression chamber of another one of the piston assemblies. The first volume of a first piston assembly may fluidly communicate with the first volume and the second volume of a second piston assembly, and the first volume of a third piston assembly may fluidly communicate with the first volume and the second volume of the second piston assembly.