Briefs: Physical Sciences
A method that includes the use of modified equations of state has been developed to enable noniterative, efficient computation of the thermodynamic behaviors of gases and liquids at...
Briefs: Materials
The figure schematically illustrates an apparatus and process in which a continuous tow of silicon carbide fibers is coated and infiltrated with a polymer/silicon slurry. A compact of such...
Briefs: Manufacturing & Prototyping
An improved process has been devised for making closed channels (e.g., coolant channels) in a heat-exchanger liner or a similar metal object. The process involves the following steps:...
Briefs: Materials
The figure illustrates one of several related pin-puller mechanisms that harness the recovery characteristics of a shape-memory alloy (SMA). Like some other SMA-actuated mechanisms...
Briefs: Electronics & Computers
Three coplanar-stripline circuits have been designed to perform coupling and filtering functions in microwave systems. These circuits could be incorporated into feed networks for microwave...
Briefs: Photonics/Optics
Data signals can be transmitted via the same optical fibers that are used to transmit power from base stations to remote stations containing sensors and associated circuitry. [A prototype...
Briefs: Materials
An accelerated-testing method has been developed for evaluating the effectiveness of various measures taken to prevent the corrosion of steel reinforcing bars ("rebars") cast into concrete. Such measures can include chemical admixtures incorporated into the concrete, coatings, penetrants,...
Briefs: Medical
A compact fiber-optic probe has been found to be useful for noncontact diagnosis of interior parts of eyes. The probe was originally developed for performing...
Briefs: Photonics/Optics
A great increase in the effectiveness of fiber optic systems is possible with a device that allows for simultaneous two-way signalling of multiple data streams on a single optical fiber....
Briefs: Physical Sciences
A generalized mathematical model has been devised for use in analyzing the pyrolysis of arbitrarily specified (but typical) biomass feedstocks at atmospheric pressure. The model represents...
Briefs: Mechanical & Fluid Systems
A brief report summarizes the design of the lightweight, high-torque wheel drive of a small robotic vehicle used to explore the surface of Mars. Planetary gearing was selected for compactness and high torque capability. The input stages were fitted with ball bearings to survive the cold (down to -100 °C) Martian...
Briefs: Electronics & Computers
An improved motor controller provides a circuit that will allow a motor to run at full speed while traveling from point A to point B, and still be able to obtain the desired damping...
Briefs: Motion Control
The tunable external cavity diode laser is an important new tool used to evaluate and test the latest fiber-optic components and building blocks of modern telecommunications systems. A key factor...
Briefs: Materials
A technique of gentle, highly selective gas-phase etching of silicon has been devised to enable the fabrication of microelectromechanical devices integrated with electronic circuits. For example,...
Briefs: Materials
Thermal-insulation blankets developed for use aboard the space shuttle can be adapted to a racing car to protect the driver against excessive cockpit heating. [Also see an earlier article...
Briefs: Electronics & Computers
A signaling-and-detection scheme has been proposed for use in conjunction with the remote-monitoring concept described in "Beacon Monitoring Would Reduce Interactions With Remote Systems" (NPO-19706), NASA Tech Briefs, Vol. 21, No. 5 (May 1997), page 54. To recapitulate: A remote system (a...
Briefs: Robotics, Automation & Control
A prototype manipulator system that includes two different arms has been tentatively selected for use on a semiautonomous robotic vehicle called Rocky 7 (see figure). [A previous version of this vehicle...
Briefs: Physical Sciences
The Automated Window Inspection Device (AWID) is a prototype apparatus for computer-controlled, noncontact inspection of windows, with reproducible positioning and electronic recording of data on the...
Briefs: Photonics/Optics
A proposed electro-optical image-processing system would enable remote viewing of an object through a multimode optical fiber, as though the fiber were a conventional image-transmitting optic like a lens...
Briefs: Mechanical & Fluid Systems
Rigid, guyed masts of a proposed type for supporting meteorological instruments would be designed to withstand considerably stronger winds than those conventionally used. The proposed fairings...
Briefs: Physical Sciences
A mathematical model of a special class of solid/fluid chemical reactions has been developed for use in analyzing the pyrolysis of particles of cellulose, wood, and similar biomass materials....
Briefs: Physical Sciences
A mathematical model has been developed for use in assessing the performances of direct-contact pyrolysis reactors used to convert particles of raw biomass materials (usually small wood...
Briefs: Physical Sciences
A highly sensitive micromachined accelerometer that is intended to be exposed to very small accelerations during operation incorporates features for protection against much larger...
Briefs: Information Technology
The Schedule and Cost Risk Analysis Modeling System (SCRAM) computer program identifies important sources of schedule and cost risks in an operational process. The related Process Analysis and Improvement Support System (PASS) program assists in the overall analysis and improvement of an operational...
Briefs: Electronics & Computers
An operator interface is undergoing development along with other subsystems of a robot that would assist in caring for elderly and disabled patients. This development has been initiated in...
Briefs: Information Technology
Decision-support software based on discrete-event simulation (DES) has been undergoing development for use in planning and scheduling work in the Orbiter Processing Facility (OPF) at Kennedy Space Center. The software is also suitable for adaptation to similar use in other facilities...
Briefs: Physical Sciences
A report presents an evaluation of eight mathematical models of the evaporation of liquid droplets — models that are used in the numerical simulation of a variety of gas/liquid flows, including cooling sprays, burning liquid-fuel sprays, fire-suppression sprays, and air/fuel-premixing...
Briefs: Software
The Dynamics Algorithms for Real-Time Simulation (DARTS) computer program solves the equations of motion of tree-topology, flexible, and/or multibody mechanical systems as diverse as molecules, mechanisms, robots, spacecraft, and ground vehicles. It has proven to be particularly useful for...
Briefs: Electronics & Computers
Hybrid high-temperature-superconductor (HTS)/semiconductor planar oscillator circuits that operate at a frequency of 8.4 GHz have been developed. In the original intended application, one...