A three-dimensional (3D) printer includes an ejector and a coil wrapped at least partially around the ejector. The 3D printer also includes a power source configured to transmit voltage pulses to the coil. The 3D printer also includes a computing system configured to cause the power source to transmit the voltage pulses to the coil in intermittent bursts. The voltage pulses in each burst occur at a burst frequency from about 60 Hz to about 2000 Hz. The coil causes a drop of printing material to be jetted through a nozzle of the ejector in response to each voltage pulse. The drops generated in response to the voltage pulses in each burst land at substantially a same location in a horizontal plane.

The invention includes apparatus and methods for instantiating precious metals in a nanoporous carbon powder.

The invention includes apparatus and methods for instantiating precious metals in a nanoporous carbon powder.

There are provided reactive metal powder in-flight heat treatment processes. For example, such processes comprise providing a reactive metal powder; and contacting the reactive metal powder with at least one additive gas while carrying out said in-flight heat treatment process, thereby obtaining a raw reactive metal powder.

There are provided reactive metal powder in-flight heat treatment processes. For example, such processes comprise providing a reactive metal powder; and contacting the reactive metal powder with at least one additive gas while carrying out said in-flight heat treatment process, thereby obtaining a raw reactive metal powder.

In an aspect, a method for making a metal-containing material comprises steps of: forming a metal-containing hydrogel from an aqueous precursor mixture using a photopolymerization; wherein the aqueous precursor mixture comprises water, one or more aqueous photosensitive binders, and one or more aqueous metal salts; and thermally treating the metal-containing hydrogel to form the metal-containing material; wherein the metal-containing hydrogel is exposed to a thermal-treatment atmosphere during the step of thermally treating; wherein a composition of the metal-containing material is at least partially determined by a composition of the thermal-treatment atmosphere during the thermally treating step.

In an aspect, a method for making a metal-containing material comprises steps of: forming a metal-containing hydrogel from an aqueous precursor mixture using a photopolymerization; wherein the aqueous precursor mixture comprises water, one or more aqueous photosensitive binders, and one or more aqueous metal salts; and thermally treating the metal-containing hydrogel to form the metal-containing material; wherein the metal-containing hydrogel is exposed to a thermal-treatment atmosphere during the step of thermally treating; wherein a composition of the metal-containing material is at least partially determined by a composition of the thermal-treatment atmosphere during the thermally treating step.

A method for producing fine copper particles includes producing fine copper particles having a coating film containing cuprous oxide on a surface by heating copper or a copper compound in a reducing flame formed by a burner. The fine copper particles are produced by adjusting a mixing ratio between a combustible gas and a combustion supporting gas which form the reducing flame such that a volume ratio of CO/CO.sub.2 is in a range of 1.5 to 2.4.

Reactor configurations may include one or more staged inlets and/or one or more staged outlets for gaseous and solid feedstocks. In one embodiment of the present disclosure, a reactor design for gas-solid reaction with one or more additional outlet for gas and/or solid phase is provided. In yet another embodiment, the design for a gas-solid reactor with one side inlet and two outlets for gas phase is described. In one embodiment, a reactor design with pairs of inlet and outlet for both gas and solid phase is provided. In another embodiment, a reactor design with one or more side inlets but only one outlet for gas phase is provided. In yet another embodiment, a reactor design with two inlets at the top/bottom of reactor and two side outlets for gaseous phase is described. In yet another embodiment, a reactor design with one or more side inlets and outlets for both gas and solid phases is provided.

The present invention relates to a method for manufacturing a needle-shaped or rod-shaped porous iron powder. Specifically, the present invention provides a method for manufacturing a needle-shaped or rod-shaped porous iron and a needle-shaped or rod-shaped porous iron powder manufactured thereby, the method comprising the steps of: preparing a ferrous chloride dehydrate by concentrating a ferrous chloride aqueous solution; solid-liquid separating the ferrous dichloride to prepare ferrous chloride dehydrate powder; oxidizing the ferrous chloride dehydrate powder; and reducing the oxidized ferrous chloride powder.