Briefs: Mechanical & Fluid Systems

A leak-free valve has been proposed as a more reliable, less expensive, adaptable alternative to a one-time-opening, pyrotechnically actuated valve (pyrovalve). In the original intended application, the pyrovalve...

Briefs: Mechanical & Fluid Systems

Pneumatic cushions have been proposed for protecting the afterbodies of two-body instrumented soil-penetrator projectiles. These cushions would be, essentially, doughnut-shaped...

Briefs: Mechanical & Fluid Systems

Work performed at Johnson Space Center has brought about a major improvement in the means for measuring the bending that occurs whenever stress is applied to a bolted joint. This major improvement...

Briefs: Manufacturing & Prototyping
Improvements in Rapid Prototyping

Several improvements have been proposed for the fabrication process known as "rapid prototyping." In this process, a model or prototype of a solid object is built up by controlled ejection of molten polymeric material through programmed orifices to form patterned layers. The second layer is deposited on top of...

Briefs: Physical Sciences

An electron-beam ionizer has been designed to deliver ions to the entrance apertures of nine miniature quadrupole mass spectrometers in an array. A similar electron-beam ionizer could also...

Briefs: Physical Sciences

A computer-controlled instrumentation system has been developed for use in measuring concentrations of various atomic species in the exhaust gases of a space-shuttle main engine on a...

Briefs: Physical Sciences

The figure presents additional information on the optics of the atomic-absorption-spectroscopy (AAS) system described in the preceding article. The optics include (1) a periscopic...

Briefs: Physical Sciences

A technique for ultrasonic characterization of plates has been extended to tubes and curved structures in general. In this technique, as explained in more detail below, one performs...

Briefs: Physical Sciences
Detecting Metal Ions by Voltammetry Using Diamond Electrodes

Experiments have demonstrated the feasibility of detecting multiple species of toxic metal ions and other ions of interest dissolved in water, by means of voltammetry with electrically conductive artificial diamond electrodes. Diamond is attractive as an electrode material because it...

Briefs: Information Technology

A preconditioning technique has been developed for numerical solution of the Helmholtz equation as applied to the steady-state propagation of sound in a semi-infinite,...

Briefs: Information Technology

A digital processing technique for separating two cochannel frequency-modulation (FM) signals involves a partial algebraic solution that gives the phases of the two signals to within...

Briefs: Materials
Tribological Characterization of Solid Surfaces

Reports labeled as chapters 2, 3, 4, 7, 8, 9, and 10 of a NASA technical memorandum that addresses topics in tribology have been compiled into a document that emphasizes those aspects of the subject matter that pertain to chemical-vapor-deposited (CVD) diamond and diamond-like films. The...

Briefs: Physical Sciences
Small Balloons for Local Aerial Exploration of Mars

A report proposes the use of lightweight balloon-borne instrumentation systems for exploration in the vicinity of a lander on the surface of Mars. Each system would comprise instrumentation with a mass of about 0.2 kg and a balloon with a mass of about 0.8 kg and volume of about 50...

Briefs: Mechanical & Fluid Systems
Using Electromagnetic Drag on Tethers To De-Orbit Spacecraft

Two papers propose the use of electrically conductive tethers to remove spent or dysfunctional spacecraft from orbit around the Earth in order to reduce the hazard of orbital debris. In comparison with onboard rockets, these tethers would be more cost-effective, more reliable, and...

Briefs: Physical Sciences

An optoelectronic apparatus and a technique for its operation have been developed to facilitate and accelerate the measurement of distances of the order of tens of feet to within...

Briefs: Electronics & Computers

A portable, battery-powered camera unit contains a programmable digital camera that is implemented on a single chip utilizing active-pixel-sensor (APS) technology, plus circuitry for...

Briefs: Materials

An improved method of accelerated testing reduces the time needed to analyze the abilities of zinc-rich primers to protect steel substrates against corrosion in a seacoast...

Briefs: Photonics/Optics

A developmental electro-optical system would enable remote real-time viewing of a scene through a multimode optical fiber, as though the fiber were a conventional image-transmitting optic...

Briefs: Photonics/Optics

Precise small apertures for a variety of optical applications can be formed in silicon-on-insulator (SOI) wafers by use of a photolithographic process developed specifically for the...

Briefs: Photonics/Optics

A method of processing phase measurements in an unequal-arm laser Michelson interferometer makes it possible to detect phase effects much smaller than the laser phase noise. In...

Briefs: Photonics/Optics

The figure depicts several aspects of a unique type of vertical-cavity surface-emitting lasers (VCSELs) that incorporate fiber Fabry-Perot (FFP) optical cavities. These lasers have been...

Briefs: Photonics/Optics

The size of a holographic data-storage system could be reduced by a proposed design modification that calls for replacement and repositioning of some optical components and the use of...

Briefs: Photonics/Optics

Monolithic semiconductor photodiodes that discriminate against infrared and visible light and that can be tailored to detect ultraviolet light in selected wavelength bands have been...

Briefs: Photonics/Optics

Pulse shepherding (defined below) can be exploited to impress synchronized amplitude-modulation pulses, with durations of the order of picoseconds, onto beams of light with...

Briefs: Photonics/Optics

A dynamic-light-scattering (DLS) method that reduces undesired contributions from multiply scattered photons has been invented. The method involves, among other things,...

Briefs: Photonics/Optics

Under a Phase 1 Small Business Technology Transfer (STTR) award of $99,000 with Goddard Space Flight Center, Advanced Optical Systems Inc. (AOS) has produced a 13.5-kg/m2 6-in.-diameter...

Briefs: Medical

Wearable sensor patches — miniature biotelemetric units — have been proposed for use in measuring temperature, heart rate, blood pressure, and possibly other physiological parameters....

Briefs: Physical Sciences

Figure 1 schematically depicts an experimental setup in which Rayleigh scattering from molecules of a flowing gas is used to measure the temperature and one component of the...

Briefs: Electronics & Computers
Integrated Optical Voltage-Measuring Apparatus

An integrated optical voltage-measuring apparatus based on a Mach-Zehnder interferometer has been designed and constructed. The main feature of this apparatus is that optical fibers link part of it to an optical sensor head placed at the source of the voltage to be measured, whether the source be a...

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