Briefs: Physical Sciences
Weighted-Hyperbola Technique for Locating Pulsed Sources

The weighted-hyperbola technique is an iterative computational technique for processing data on the times of arrival of pulsed signals at more than four observing stations to determine location (in both space and time) of origin of the signals. (The location is overdetermined when data...

Briefs: Electronics & Computers

During the development and testing of signal processing systems, it is useful to generate test signals in the laboratory in order to quantify system parameters such as dynamic range,...

Briefs: Manufacturing & Prototyping

The need for improved investment castings at Marshall Space Flight Center's Rapid Prototyping Lab has led to the development of a simple machine for centrifugal investment casting of shells....

Briefs: Information Technology

Modified Taguchi techniques of robust design optimization are used in an innovative method of training artificial neural networks — for example the network shown in the figure. As...

Briefs: Manufacturing & Prototyping

A simple change in the design of tools used in manufacturing laminated-composite-material sandwich panels reduces the floor area needed to store the tools. To give meaning to a...

Briefs: Physical Sciences

The figure shows the basic optical configuration of an improved all-reflecting imaging spectrometer. This spectrometer would differ from older spectrometers in several respects, one...

Briefs: Information Technology
Software for Assessing Effects of Designs on Operations

The Operations Impact Assessor (OIA) computer program facilitates rapid assessment of the effects of designs of spacecraft on spacecraft-processing operations at a launch site. OIA is a user-friendly, object-oriented, artificial-intelligence application program that features model-based...

Briefs: Electronics & Computers
Process for Fabrication of Micro Fluidic Structures

Through an innovative microfabrication process, enclosed microstructures are created for "laboratory on a chip" applications, such as medical diagnostics. These microstructures include capillaries, tunnels, pipettes, reaction vessels, and cavities. Using only conventional lithographic...

Briefs: Robotics, Automation & Control

An analysis of empirical data on low-frequency oscillations in the inlet flow of a turbopump has led to the conclusion that these oscillations could be reduced or eliminated with...

Briefs: Materials

The alumina for making a suspension according to this concept must be in the form of a highly pure (preferably >99.99 percent) powder with a suitable particle-size distribution...

Briefs: Physical Sciences

A heat exchanger made largely from pieces of single-crystal silicon has been designed for use as a recuperator in a reverse-Brayton-cycle cryocooler. Its design is optimized for transferring...

Briefs: Electronics & Computers

The figure illustrates a lightweight composite-material dual-beam reflector antenna for the SeaWinds spaceborne scatterometer instrument, which operates in the Ku band and is designed to...

Briefs: Manufacturing & Prototyping

Processes for fabricating thin-film type-S thermocouples on metal and silicon nitride substrates (see figure) have been developed. (A type-S thermocouple comprises one leg made of platinum and...

Briefs: Information Technology

An improved method of analysis and design offers the potential to enhance the performances of adaptive feedforward tracking systems. The method can, in principle, make it possible to...

Briefs: Mechanical & Fluid Systems
Flexible Actuators for Small, Mobile, Special-Purpose Robots

A report discusses flexible microactuators for a proposed generation of small, mobile, special-purpose robots. Aspects of this topic were discussed in two previous articles in NASA Tech Briefs: "Thin-Film, Light-Energized Bimorph Micromechanical Actuators" (NPO-19607), Vol. 20, No. 8...

Briefs: Electronics & Computers

The sight-to-touch translator (ST3) is a conceptual electronic apparatus that would generate a tactile representation of visible objects in its vicinity. The ST3 would be worn by a blind...

Briefs: Software
Software for Tooth-Contact Analysis of Spiral Bevel Gears

The SBGTAPER computer program implements a method for design and generation of spiral bevel gears that feature tapered teeth with localized bearing contact and a low level of transmission errors. The influence of misalignment on transmission errors and shift of bearing contact were...

Briefs: Information Technology
Expressing Object-Oriented Concepts in Fortran 90

A methodology for object-oriented programming in Fortran 90 has been developed. The methodology provides for emulation of the most important object-oriented concepts of C++; namely, classes (including abstract data types, encapsulation, and function overloading), inheritance, and dynamic...

Briefs: Mechanical & Fluid Systems

The figure presents a simplified view of a shaft seal that provides a small flow of neutral buffer gas to prevent contact between different gases contained in two adjacent regions along the shaft. In the original application,...

Briefs: Electronics & Computers

Sensors made largely of commercially available optical and electronic components are being developed for use in measuring small horizontal displacements of payloads suspended below...

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: Mechanical & Fluid Systems

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: Electronics & Computers

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: Physical Sciences

The figure illustrates an apparatus for measuring heat-transfer and pressure-drop characteristics of porous plug specimens in oscillating flows. The apparatus is built around an...

Briefs: Materials
Testing Corrosion Prevention in Reinforced Concrete

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...

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