Abstract: A system and method is described to precisely control the pressure in a sample chamber over a wide range of pressures. The system comprises a sample chamber connected to additional chambers via on-off valves. The volumes of these chambers are accurately pre-measured. The valves can be electronically controlled by a controller, such as a computer with a processor. Computer control of these valves to vary the pressures in the chambers to achieve a precise target pressure in the sample chamber is performed in a sequence of steps where the pressure in each chamber is calculated after each step, thereby eliminating the requirement of measuring the actual pressure in the chambers.

Abstract: The disclosure describes a method of producing iron nitride magnets using Zn-doped iron oxide precursors. The iron oxide precursors are reduced and nitrided to produce a powder containing iron nitride in the Fe16N2 phase. The inclusion of Zn in the iron oxide precursor enhances the magnetic properties of the iron nitride powder.

Abstract: The present invention employs Equal Channel Angular Extrusion (ECAE) to consolidate Fe16N2, Fe4N, Sm2Fe17Nx, either alone or in combination with other magnetic powders made from Nd2Fe14B, SmCo5, Sm2Co17, Sm2Fe17Nx and MnBi to prepare dense bodies at temperatures as low as room temperature or as high as 800° C., depending on the composition. When a soft magnetic material such as ?-Fe powder or Fe4N powder is mixed with a hard magnetic material such as Nd2Fe14B, SmCo5, Sm2Co17 or Sm2Fe17Nx or MnBi or FeCr alloys or a semi-hard material such as Fe16N2, exchange-coupled magnets are obtained. This is due to the fact that the current theory on exchange-coupling phenomena indicates that a nanocrystalline size of the soft magnetic material is a necessary condition for the promotion of exchange-coupling.

Abstract: A method of making iron nitride powder is provided. The method comprises the steps of: a) providing an iron-based starting material; b) reducing the starting material by heating the starting material in a fluidized bed reactor in the presence of a reducing agent; c) nitriding the material obtained from step (b) by contacting the material with a nitrogen source. Also provided is the iron nitride powder made by the above method.

Abstract: A method of making iron nitride powder is provided. The method comprises the steps of: a) providing an iron-based starting material; b) reducing the starting material by heating the starting material in a fluidized bed reactor in the presence of a reducing agent; c) nitriding the material obtained from step (b) by contacting the material with a nitrogen source. Also provided is the iron nitride powder made by the above method.

Abstract: A motor controller system (15a) for dc power source motors (10) which includes a sensor device (16) that operates to measure and generate a voltage signal from the motor current and the rate of change of said current, and a programmable input/output processor (12) which receives voltage signals as input from the motor current, dc power source (11) and/or motor (10) and compares on or more of these voltage signals to one or more control parameters. Based upon these comparisons, the processor (12) generates a pulse width modulation control signal, which triggers a switching mechanism (14) and related interrupt service routing to make adjustments to the operational parameters of the motor by periodic interruption of the motor current.

Abstract: A motor controller system (15a) for dc power source motors (10) which includes a sensor device (16) that operates to measure and generate a voltage signal from the motor current and the rate of change of said current, and a programmable input/output processor (12) which receives voltage signals as input from the motor current, dc power source (11) and/or motor (10) and compares on or more of these voltage signals to one or more control parameters. Based upon these comparisons, the processor (12) generates a pulse width modulation control signal, which triggers a switching mechanism (14) and related interrupt service routing to make adjustments to the operational parameters of the motor by periodic interruption of the motor current.

Abstract: A magnetic sweeper 20 is disclosed for capturing airborne particles which exhibit ferromagnetic behavior. The magnetic sweeper 20 uses a magnet(s) 43 having a magnetic field strength which captures particles coming within a predetermined distance of the magnet 43. A non-magnetic endless belt 31 is arranged about the magnet 43, wherein the particles are impinged against the belt 31 by the magnetic field lines of flux. This area is defined as a particle capturing first station. The belt 31 moves the captured particles further away from the magnet 43 to a second station. Located at the second station is a collector which includes a vacuum, a brush 41 and a particle flange. As will be appreciated by those skilled in the art, the magnetic field strength diminishes with distance from the magnet 43. Accordingly, after a certain distance from the magnet 43, the field strength drops to a point where the particles fall from the belt 31.