Abstract: An example of an ultraviolet (UV) light fusing agent for three-dimensional (3D) printing includes a vehicle and a multi-functional antioxidant and UV light absorber dispersed in the vehicle. The vehicle includes water and a water miscible or water soluble organic solvent. The multi-functional antioxidant and UV light absorber includes a metal oxide particle that is to absorb UV radiation having a wavelength within a range from about 330 nm to about 405 nm and a passivating agent complexed with at least a portion of a surface of the metal oxide.

Abstract: An example computing device comprises a memory to store control instructions, and a processor to: perform a first authentication of the control instructions using a first key; and in response to receipt of a command to enable a second authentication of the control instructions, add a second key to a one-time programmable portion of the memory, wherein the command is signed using the first key, the second key to perform a second authentication of the control instructions with the first key to perform the first authentication of the control instructions.

Abstract: Examples of methods are described herein. In some examples, a method includes determining a graph representation of a three-dimensional (3D) object. In some examples, the graph representation includes nodes and edges associated with the nodes. In some examples, each node includes a temperature profile attribute. In some examples, the method includes predicting, using a machine learning model, a deformation of the 3D object based on the graph representation.

Abstract: Examples of a three-dimensional (3D) printing kit include a particulate build material and a binder fluid. The particulate build material includes from about 80 wt % to 100 wt % metal particles based on a total weight of the particulate build material. In some examples, the binder fluid includes water, polymer particles in an amount ranging from about 1 wt % to about 40 wt % based on a total weight of the binder fluid, and a blocked polyisocyanate adhesion promoter in an amount ranging from about 0.05 wt % to about 5 wt % based on the total weight of the binder fluid. In some other examples, the binder fluid includes water and the polymer particles, and the 3D printing kit further includes an adhesion promoter fluid which includes water and the blocked polyisocyanate adhesion promoter.

Abstract: An example of a multi-fluid kit for three-dimensional (3D) printing kit includes a fusing agent and a build material reactive functional agent. The fusing agent includes water and an electromagnetic radiation absorber. The build material reactive functional agent includes a vehicle and trifluoroacetic anhydride. The multi-fluid kit may also be part of a 3D printing kit.

Abstract: A fluid ejection device may include a fluid ejection die including nozzles and fluid feed holes. Each nozzle may have a nozzle orifice formed in a top surface of the fluid ejection die. The fluid feed holes may be formed in a bottom surface of the fluid ejection die and fluidly connected to the nozzles. The fluid ejection device may include a molded panel into which the fluid ejection die is at least partially embedded, the molded panel having a fluid slot formed therethrough such that the fluid slot is fluidly connected to the fluid feed holes of the fluid ejection die, the molded panel formed with a mold chase and a release liner coupled to and at least partially covering an interior surface of the mold chase, the mold chase having a fluid slot feature corresponding to the fluid slot.

Abstract: Examples in accordance with the present disclosure are directed to a method including generating a negative fluid pressure between a fluid supply and a first port of a fluidic ejection device, and generating a positive fluid pressure between the fluid supply and a second port of the fluidic ejection device. The method further includes selectively activating a first priming pump connected to the first port in response to an indication that the first port is transitioning from an open state to a closed state, wherein the selective activation of the first priming pump causes the first port to remain in the open state and causes fluid within the fluidic ejection device to exit through the first port and to recirculate along a fluid flow path.

Abstract: Examples herein involve amplification and detection of nucleic acids using a microfluidic reaction chamber. An example apparatus includes a reaction-chamber circuit to process a reagent and a biologic sample for amplification of nucleic acids. The apparatus further includes a plurality of capillaries to pass the reagent and the biologic sample through the microfluidic reaction chamber. A valve control system may selectively control each of a plurality of valves to cause the reagent and the biologic sample to selectively move through the microfluidic reaction chamber for the amplification of the nucleic acids according to a particular timing sequence. In various examples, a trapping region disposed in the microfluidic reaction chamber secures the nucleic acids in the microfluidic reaction chamber for amplification using the reaction-chamber circuit.

Abstract: A method is described in which a difference in height is determined between a current position and a calibration position of a printhead of a printer. An alignment value for the printhead is then determined based on the difference.

Abstract: In some examples, a fluidic die includes an arrangement of fluidic elements to dispense a fluid, each fluidic element of the fluidic elements including a fluidic actuator and a fluid chamber. An array of fluid feed holes is arranged in a plurality of dimensions to communicate the fluid with the fluidic elements, where each of multiple fluid feed holes along a first dimension of the plurality of dimensions is distinct from multiple fluid feed holes along a second dimension of the plurality of dimensions. The fluidic die includes first circuit elements operable at a first power supply voltage, the first circuit elements interspersed in regions between the fluidic elements along different axes of the fluidic die.

Abstract: A fluidic die includes fluid-transfer elements, and a temperature sensor to monitor a temperature on the fluidic die. The fluidic die includes a trickle-warming circuit to warm fluid transferrable by the fluid-transfer elements, and a pulse-warming circuit to warm the fluid. A warming control circuit selectively activates the trickle-warming and pulse-warming circuits.

Abstract: A toner refill cartridge includes a body member in which a toner is contained and which includes a toner discharge port through which the toner is discharged: a driving power input portion rotatable by a driving power from outside the toner refill cartridge; an agitating member to agitate the toner while being rotated by a rotation power from the driving power input portion; and a discharge completion display module including a moving display portion to move in response to the rotation power from the driving power input portion, and a fixed display portion whose position is fixed with respect to the body member, the discharge completion display module to indicate whether the toner contained in the body member has been completely discharged, based on a position relationship of the moving display portion with respect to the fixed display portion.

Abstract: A fluid-ejection printhead includes a sparse array of fluid-ejection nozzles through which fluid is ejected onto dot rows parallel to a scan axis of the fluidejection printhead. The fluid is ejected by more than one fluid-ejection nozzle of the sparse array onto each dot row. The fluid-ejection printhead includes fluidejection element. Each element can correspond to a pair of the fluid-ejection nozzles through which the fluid is ejected onto a same dot row and include a corresponding pair of fluid-ejection actuators. Each element can instead correspond to one of the fluid-ejection nozzles and include one fluid-ejection actuator.

Abstract: The present disclosure describes multi-fluid kits for three-dimensional printing, materials kits for three-dimensional printing, and methods of making three-dimensional printed articles. In one example, a multi-fluid kit for three-dimensional printing can include a fusing agent and a pore-promoting agent. The fusing agent can include water and a radiation absorber. The radiation absorber can absorb radiation energy and convert the radiation energy to heat. The pore-promoting agent can include water and a water-soluble pore-promoting compound. The pore-promoting compound can chemically react at an elevated temperature to generate a gas.

Abstract: A multi-fluid kit for three-dimensional printing can include a fusing agent and a coloring agent. The fusing agent can include an electromagnetic radiation absorber in a first liquid vehicle. The electromagnetic radiation absorber can absorb radiation energy and can convert the radiation energy to heat. The coloring agent can include a magenta rhodamine dye and a fluorescence quenching iodide salt in a second liquid vehicle. A molar ratio of the magenta rhodamine dye to the fluorescence quenching iodide salt can range from about 1:1 to about 1:10.

Abstract: Examples of methods for model prediction are described herein. In some examples, a method includes predicting a compensated model. In some examples, the compensated model is predicted based on a three-dimensional (3D) object model. In some examples, a method includes predicting a deformed model. In some examples, the deformed mode is predicted based on the compensated model.

Abstract: Examples of methods are described. In some examples, a method includes determining a quantification of a spatial neighborhood of a voxel of a build volume. In some examples, the method includes predicting, using a machine learning model, a manufacturing powder degradation based on the quantification and a position of the voxel.

Abstract: Examples of methods are described. In some examples, a method includes determining objects corresponding to a manufacturing period of three dimensional (3D) printing. In some examples, the method includes packing build volumes based on the objects. In some examples, the method includes simulating manufacturing powder degradation based on the build volumes. In some examples, the method includes determining a quantity of manufacturing powder consumption based on the manufacturing powder degradation. In some examples, the method includes adjusting a manufacturing parameter based on the quantity of manufacturing powder consumption.