Manufacturing & Prototyping

Serrating Nozzle Surfaces for Complete Transfer of Droplets

A method of ensuring the complete transfer of liquid droplets from nozzles in microfluidic devices to nearby surfaces involves relatively simple geometric modification of the nozzle surfaces. The method is especially applicable to nozzles in print heads and similar devices required to dispense liquid droplets having precise volumes. Examples of such devices include heads for soft printing of ink on paper and heads for depositing droplets of deoxyribonucleic acid (DNA) or protein solutions on glass plates to form microarrays of spots for analysis.

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Triaxial Swirl Injector Element for Liquid-Fueled Engines

The design is amenable to low-cost production.A triaxial injector is a single bi-propellant injection element located at the center of the injector body. The injector element consists of three nested, hydraulic swirl injectors. A small portion of the total fuel is injected through the central hydraulic injector, all of the oxidizer is injected through the middle concentric hydraulic swirl injector, and the balance of the fuel is injected through an outer concentric injection system. The configuration has been shown to provide good flame stabilization and the desired fuel-rich wall boundary condition.

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Coaxial Propellant Injectors With Faceplate Annulus Control

These injectors are simpler and less expensive, relative to prior coaxial injectors.An improved design concept for coaxial propellant injectors for a rocket engine (or perhaps for a non-rocket combustion chamber) offers advantages of greater robustness, less complexity, fewer parts, lower cost, and less bulk, relative to prior injectors of equivalent functionality. This design concept is particularly well suited to small, tight-tolerance injectors, for which prior designs are not suitable because the practical implementation of those designs entails very high costs and difficulty in adhering to the tolerances.

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Adaptable Diffraction Gratings With Wavefront Transformation

Better resolution and aberration control are possible with a dynamic refractive grating.Diffraction gratings are optical components with regular patterns of grooves, which angularly disperse incoming light by wavelength. Traditional diffraction gratings have static planar, concave, or convex surfaces. However, if they could be made so that they can change the surface curvature at will, then they would be able to focus on particular segments, self-calibrate, or perform fine adjustments.

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Brushless DC Rotary Motor Improves Efficiency in Fuel Cell Applications

Design uses thin- walled stator to achieve high power density. The designers and manufacturers of fuel cells are continually striving to improve the efficiency of their products. A design challenge facing the engineer relates to reducing the power demands of the many electrical systems that support fuel cell operation. Blowers, compressors, and pumps are necessary for fuel pump operation, but are considered parasitic electrical loads. Since they require power from the fuel cell itself they impact overall system efficiency. To be truly effective in fuel cell applications, the motors used to drive the pumps must be lightweight, compact, and as efficient as possible in order to provide more energy for the intended application.

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Preparation of Regular Specimens for Atom Probes

Single- or multiple-tip specimens can readily be prepared. A method of preparation of specimens of non-electropolishable materials for analysis by atom probes is being developed as a superior alternative to a prior method. In comparison with the prior method, the present method involves less processing time. Also, whereas the prior method yields irregularly shaped and sized specimens, the present developmental method offers the potential to prepare specimens of regular shape and size.

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Wheel Design Verified With FEA Software

This paper examines an aluminum wheel design used with a run-flat tire called an extended mobility technology (EMT) tire, which can be safely driven without air for at least 80 km (50 miles). The setup of the finite element model of the wheel is discussed in detail, along with a parametric study of the inflation pressures and resulting stresses to verify that existing wheel designs could maintain the safety benefit of controlled handling and braking, even when the tire goes flat.

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