Magazine

A family of fluorescent dye molecules has been developed for use in "on-off" fluorescence detection of specific chemicals. By themselves, these molecules do not fluoresce. However, when exposed to certain chemical analytes in liquid or vapor forms, they do fluoresce (see figure). These...

A new membrane composite material that combines an organosilica proton conductor with perfluorinated Nafion material to achieve good proton conductivity and high-temperature performance for membranes used for fuel cells in stationary, transportation, and portable applications has...

Optical delay lines of a proposed type would be made from rods of such dielectric materials as calcium fluoride, fused silica, or sapphire. These would offer advantages over prior optical delay lines, as summarized below.

Artificial neural networks comprising spiking neurons of a novel type have been conceived as improved pattern- analysis and pattern- recognition computational systems. These neurons are represented by a mathematical model denoted the state- variable model (SVM), which among other things, exploits a...

Symmetrical phase-only filtering (SPOF) can be exploited to obtain substantial improvements in the results of data processing in particle- image velocimetry (PIV). In comparison with traditional PIV data processing, SPOF PIV data processing yields narrower and larger amplitude correlation...

A document discusses overcoming efficient optical coupling to high orbital momentum modes by slightly bending the taper dispersive element. This little shape distortion is not enough to scramble the modes, but it allows the use of regular, free-beam prism coupling, fiber coupling, or planar...

A report discusses the ability to control the attitude and translation degrees-of-freedom of a solar sail vehicle by changing its center of gravity. A movement of the spacecraft's center of mass causes solar- pressure force to apply a torque to the vehicle. At the compact core of the...

Silicon carbide-based position sensors INPROX Technology Corp. Boston, MA 617-573-5158 www.inproxtechnology.com INPROX Technology Corp. (ITC) has entered into a Space Act Agreement (SAA) with NASA’s John H. Glenn Research Center in Ohio to develop advanced silicon carbide (SiC)- based...

Finite element modeling and analysis Dynamic Concepts Huntsville, AL 256-922-9888 www.dynamic-concepts.com NASA tasked Dynamic Concepts (DCI) with assessing the structural dynamics of the rollout process, whereby the space shuttle orbiter, external tank, and solid rocket booster...

The KEYENCE PX Series rugged photoelectric sensors from Keyence Corp. of America, Woodcliff Lake, NJ, feature an IP-69K environmental rating for highpressure (1,400 psi) applications at temperatures to 176°F. They feature stainless steel casings, sensor heads backfilled with epoxy under vacuum conditions, and...

A method of topographical mapping of a local solid surface within the range of motion of a robot arm is based on detection of contact between the surface and the end effector (the fixture or tool at the tip of the robot arm). The method was conceived to enable mapping of local...

Simulation Tool for ASCTA Microsensor Network Architecture (STAMiNA) ["ASCTA" denotes the Advanced Sensors Collaborative Technology Alliance.] is a computer program for evaluating conceptual sensor networks deployed over terrain to provide military situational awareness. This or a similar program is...

It has been proposed to place laser or radio transponders at suitably chosen locations on the Moon to increase the accuracy achievable using the Global Positioning System (GPS) or other satellite-based positioning system. The accuracy of GPS position measurements depends on the accuracy of...