Abstract: In the examples provided herein, a system includes an electrochemical sensor having two electrodes inserted in a fluid to be tested, where an alternative current (AC) voltage is applied across the two electrodes; an electrochemical sensor having two electrodes inserted in a fluid to be tested, wherein an alternative current (AC) voltage across the two electrodes; and a frequency response analyzer to analyze the measured the electrical response across multiple frequencies. The system also includes a memory to store a baseline of the electrical response across multiple frequencies, and a processor to determine from the stored baseline and the measured electrical response whether the electrical response is outside a predetermined range.

Abstract: Examples of the present disclosure are directed toward methods and system for reducing surface roughness of a cured three-dimensional (3D) printed object using a localized heat source. An example method includes applying a liquid solvent to the cured 3D printed object and heating the cured 3D printed object with the liquid solvent applied thereto to a temperature below a melting point of the cured 3D printed object using a localized heat source to reduce a surface roughness of the cured 3D printed object as compared to the cured 3D printed object prior to the application of heat.

Abstract: In a three-dimensional printing method example, a liquid functional agent is selectively applied. The liquid functional agent includes an alloying agent. A metallic build material is applied. The liquid functional agent is selectively applied before the metallic build material, after the metallic build material, or both before and after the metallic build material. The liquid functional agent patterns the metallic build material to form a composite layer. At least some of the metallic build material is exposed to energy to melt the at least some of the metallic build material to form a layer. Upon contact or after energy exposure, the alloying agent and the build material alter a composition of the composite layer.

Abstract: A particulate build material for three-dimensional printing can include from about 80 wt % to about 99.5 wt % of a polyamide particles, and from about 0.5 w % to about 7.5 wt % of thermally conductive particles including cubic lattice structured particles of carbon, cubic lattice structured particles of boron and nitrogen, or a combination thereof.

Abstract: A three-dimensional printing kit can include a polymer build material and a fusing agent. The polymer build material can include from about 80 wt % to about 100 wt % polymeric particles. The fusing agent can include an aqueous liquid vehicle, an electromagnetic radiation absorber to absorb radiation energy and convert the radiation energy to heat, and an endothermic decomposition compound that can undergo thermal decomposition at a temperature ranging from about 60° C. to about 400° C.

Abstract: A transfer belt assembly includes a plurality of transfer belts. The transfer belt assembly is structured to move any of an increased number of shells, a very increased number of shells, or an extremely increased number of shells through said conversion press.

Abstract: A three-dimensional printing kit can include a polymeric build material and a fusing agent. The polymeric build material can include polymer particles having a D50 particle size from about 2 ?m to about 150 ?m. The fusing agent can include an aqueous liquid vehicle including water and an organic co-solvent, a radiation absorber to generate heat from absorbed electromagnetic radiation, and from about 2 wt % to about 15 wt % of a carbamide-containing compound.

Abstract: In a three-dimensional printing method example, a liquid functional agent is selectively applied. The liquid functional agent includes an alloying agent. A metallic build material is applied. The liquid functional agent is selectively applied before the metallic build material, after the metallic build material, or both before and after the metallic build material. The liquid functional agent patterns the metallic build material to form a composite layer. At least some of the metallic build material is exposed to energy to melt the at least some of the metallic build material to form a layer. Upon contact or after energy exposure, the alloying agent and the build material alter a composition of the composite layer.

Abstract: In a three-dimensional printing method example, a liquid functional agent is selectively applied. The liquid functional agent includes an alloying agent. A metallic build material is applied. The liquid functional agent is selectively applied before the metallic build material, after the metallic build material, or both before and after the metallic build material. The liquid functional agent patterns the metallic build material to form a composite layer. At least some of the metallic build material is exposed to energy to melt the at least some of the metallic build material to form a layer. Upon contact or after energy exposure, the alloying agent and the build material alter a composition of the composite layer.

Abstract: A three-dimensional printing kit can include a polymeric build material and a fusing agent. The polymeric build material can include polymer particles having a D50 particle size from about 2 ?m to about 150 ?m. The fusing agent can include an aqueous liquid vehicle including water and an organic co-solvent, a radiation absorber to generate heat from absorbed electromagnetic radiation, and from about 2 wt % to about 15 wt % of a carbamide-containing compound.

Abstract: A transfer belt assembly includes a plurality of transfer belts. The transfer belt assembly is structured to move any of an increased number of shells, a very increased number of shells, or an extremely increased number of shells through said conversion press.

Abstract: Some examples include an additive manufacturing build object including an electrical component and a build object body. The electrical component having a varying electrical resistivity within a resistivity range of 109 ohms per square to 105 ohms per square, the resistivity range obtained by an application and fusing of a fusing component of a printing agent and build material, the printing agent applied to the build material at a predetermined saturation dosage range corresponding to the resistivity range. The build object body having a second electrical resistivity obtained by an application and fusing of the fusing component of the printing agent and the build material, the printing agent applied at a dosage below the predetermined saturation dosage range, the build object body being electrically non-conductive.

Abstract: Some examples include an additive manufacturing method for controlling electrostatic discharge of a build object. The method includes receiving data related to a build object, the data including conductivity data, selectively depositing a first portion of a printing agent onto a build material layer in a pattern of an object layer of a build object, the printing agent being electrically conductive at a predetermined dosage, the first portion deposited at less than the predetermined dosage, selectively depositing a second portion of the printing agent onto the build material layer at an area of the pattern, the printing agent at the area deposited at or above the predetermined dosage, and applying fusing energy to form the object layer, the object layer of the build object including a shell formed at the area and a core, the shell being electrically conductive and the core being electrically non-conductive.

Abstract: A transfer belt assembly includes a plurality of transfer belts. The transfer belt assembly is structured to move any of an increased number of shells, a very increased number of shells, or an extremely increased number of shells through said conversion press.