Tech Briefs

A comprehensive library of technical briefs from engineering experts at NASA and major government, university, and commercial laboratories covering all aspects of innovations in electronics, software, photonics, imaging, motion control, automation, sensors, test, materials, manufacturing, mechanical, and mechatronics.

Briefs : Mechanical & Fluid Systems
Composite-Fuselage Concept for Greater Crashworthiness

A continuing program of research is directed toward the development of crashworthy composite-material fuselages for small aircraft. These fuselages are required not only to withstand flight loads and exhibit the required aerodynamic characteristics, but also to protect occupants during...

Briefs : Physical Sciences
SINDA/FLUINT Augmented To Represent Condensable Species

The Systems Improved Numerical Differencing Analyzer/Fluid Integrator (SINDA/FLUINT) software system has been upgraded by addition of a capability for simulating fluid mixtures that include condensable vapors. SINDA/FLUINT is the NASA standard software system for computational simulation...

Briefs : Electronics & Computers
Video-Based Active Alignment System

An optoelectronic system senses rotational and translational misalignment between two objects. The system might be used in such diverse applications as aligning construction equipment, mating parts of prefabricated buildings, and aligning vehicles for docking. It could replace more-expensive alignment systems...

Briefs : Physical Sciences
Telescope/Camera Systems Based on Inflation-Deployed Optics

A report proposes the development of spaceborne telescope/camera systems that would be lightweight, relatively inexpensive alternatives to current systems based on glass mirrors. In a system of the proposed type, the primary reflector (typically a paraboloid several meters in diameter)...

Briefs : Physical Sciences
Two-Spacecraft Laser Tracking for Detecting Gravitational Waves

A paper proposes a method of mutual coherent laser tracking of two spacecraft for detecting gravitational radiation. Each spacecraft would transmit a laser beam to, and receive a similar laser beam from, the other spacecraft. Each spacecraft would also coherently transpond a laser...

Briefs : Physical Sciences
Breathing Apparatus Stores Cold Supercritical Air

The supercritical air mobility pack (SCAMP) is a prototype self-contained breathing apparatus designed for use in rescue and fire-fighting operations (see figure). The SCAMP is based on the storage of air at supercritical pressure in a temperature range slightly above that of liquid air. Like...

Briefs : Photonics/Optics
Improved Optical Sensor for Monitoring Dissolved Oxygen

An optical sensor for measuring the partial pressure of dissolved oxygen in water is based on the effect of oxygen quenching on the fluorescence lifetime of an optically excited ruthenium complex immobilized in a recently developed polymer. In the operation of this sensor, the fluorescence...

Briefs : Photonics/Optics
Miniature, Rugged Infrared Spectrometer

The figure shows a first-phase prototype of a miniature, rugged long-wavelength infrared (LWIR) spectrometer that incorporates recent advances in the design and fabrication of microelectronic and integrated optical devices. Initial development efforts have been directed toward the intended use of the...

Briefs : Electronics & Computers
Sensor Webs

Sensor webs are developmental collections of sensor pods that could be scattered over land or water areas or other regions of interest to gather data on spatial and temporal patterns of relatively slowly changing physical, chemical, or biological phenomena in those regions. Each sensor pod would be a node in a data-gathering/...

Briefs : Electronics & Computers
Microplasmic Coating Shows High Resistance to Wear, Heat and Corrosion

The process of anodizing, or controlled oxidation, of aluminum and aluminum alloys is more than seven decades old. The primary intent of anodizing aluminum and aluminum-alloy parts is to protect the highly reactive surface against corrosion in aqueous environments, such as...

Briefs : Electronics & Computers
Inflatable Reflectarray Antennas

A type of reflectarray antenna now undergoing development is based on the concept of a reflector membrane that is stretched flat by attaching it to an inflatable frame (see figure). Antennas of this type are meant to serve as lightweight, compactly stowable, reliable alternatives to conventional antennas with...

Briefs : Software
Software Library for Parallel Adaptive Mesh Refinement

A software library has been developed for use in parallel adaptive refinement of unstructured (irregular) meshes and grids in parallel scientific and engineering computing. This library can be used in finite-difference, finite-volume, and finite-element application programs that use...

Briefs : Manufacturing & Prototyping
Modified Wire Tie

A common self-locking plastic wire tie has been modified (see figure) to enable the installer to snap off excess tie material after installation, without need for a cutting tool and without creating a potentially hazardous sharp end. A typical unmodified wire tie of this type is available in any of a variety of sizes and is...

Briefs : Motion Control
Vibratory Accelerometer and Gyroscope

A device that measures both translational acceleration and rotation exploits the dynamics of a vibratory structure that resembles a clover leaf. This device is related to other vibratory accelerometers and vibratory gyroscopes in which vibrations in suitably shaped structures are excited electrostatically...

Briefs : Software
Configuration Management of Software for Designing HSCT4.0

A report discusses the development of a highly complex system of distributed-computing, multidisciplinary design-optimization software, called "CJOpt," for use in research on model 4 of the High-Speed Civil Transport (HSCT) airplane (HSCT4.0). The emphasis in the report is on the...

Briefs : Materials
Update on SiC Fiber/[MoSi₂-Matrix/Si₃N₄ Particle] Composites

A report presents updated information on the developments described in "MoSi2-Based Composite Materials for Aircraft Engines" (LEW-16617),NASA Tech Briefs, Vol. 22, No. 9 (September 1998), page 62. To recapitulate: Hybrid composites of (1) SiC-based fibers within (2)...

Briefs : Motion Control
Proper Orthogonal Decomposition in Optimal Control of Fluids

A methodology proposed for actively controlling flows involves the use of proper orthogonal decomposition (POD) to derive computational models of reduced order. The methodology could be particularly useful for controlling flows of gases and liquids in real time.

Briefs : Physical Sciences
Mathematical Modeling of Two-Phase Flow With Evaporation

A mathematical model constructed within a theoretical framework applicable to direct numerical simulation (DNS) predicts the behavior of evaporating liquid drops entrained in a turbulent shear layer.

Briefs : Mechanical & Fluid Systems
Computational Test Cases for a Rectangular Supercritical Wing

A report describes wind-tunnel experiments on a rectangular supercritical wing and presents test cases that have been selected from the archived sets of experimental data for comparison with computational fluid dynamics (CFD) predictions. In the experiments, the wing was driven in...

Briefs : Electronics & Computers
Data-Acquisition System Takes 8-Bit Samples at 1 GHz

A unique data-acquisition system converts analog input voltages to 8-bit digital data at a rate as high as 109 samples per second (1 GHz), stores the data, and makes the data available for further processing. The system is compact, is highly resistant to ionizing radiation,...

Briefs : Materials
Cheaper Polymeric Electrolyte Membranes for Fuel Cells

Proton-conductive (solid-electrolyte) membranes made from sulfonated poly(phenylether sulfone), plus membrane/electrode assemblies containing these membranes, have been developed for use in methanol fuel cells. These membranes offer two important advantages over traditional fuel-cell...

Briefs : Motion Control
Noncontact Hall-Effect Position Sensor for Harsh Environments

Spectrol has produced an innovative design for a three-terminal voltage output device that integrates a Hall-effect sensor and a patented magnetic circuit to convert radial motion into a voltage-output signal. Standard electrical angles are at 60, 75, 90, 105, 120, 135, and 150...

Briefs : Electronics & Computers
Third-Generation Data-Acquisition System Now in Operation

Dryden Flight Research Center's Flight Loads Laboratory (FLL) was constructed in 1964 for use in performing combined mechanical and thermal tests of structural components and complete flight vehicles. The FLL is also used to calibrate and evaluate flight-loads instrumentation under the...

Briefs : Information Technology
Software for Managing Distributed Real-Time Data

An all-software data server has been invented to enable any set of connected application programs to create or gain access to live data streams. (As used here, "connected" signifies running on either the same computer or on different computers and communicating via the Internet, an intranet, or...

Briefs : Electronics & Computers
Filtering To Increase Effective Yields of Image Sensor

The addition of special-purpose signal-processing circuitry has been proposed to overcome some of the deleterious effects of hardware faults in integrated-circuit image sensors of active-pixel-sensor (APS) type and possibly of other types. The mathematical basis of the method is median...

Briefs : Medical
Whole-Blood-Staining Device

A whole-blood-staining device provides a means of (1) staining white blood cells by use of monoclonal antibodies conjugated to various fluorochromes, followed by (2) lysing and fixing of the cells by use of a commercial reagent that has been diluted according to NASA safety standards. More stable than whole blood,...

Briefs : Robotics, Automation & Control
Device Assists Actuation of a Joint in a Pressure Suit

An electromechanical device implements a unique method of actuating a fabric joint in an inflatable structure  in particular, the joint in an astronaut's pressure suit. The method is based on the principle that power from an external source can be applied to a non-constant-volume joint in...

Briefs : Physical Sciences
EPRI of Distributions of Free Radicals in Polyimide Samples

A report describes experiments in which electron paramagnetic resonance imaging (EPRI) was used to determine one-dimensional spatial distributions of free radicals in two plate specimens of PMR-15 polyimide. One specimen had been postcured at a temperature of 315 °C in nitrogen, then...

Briefs : Software
On-Line System Provides Accurate Ephemeris and Related Data

The Horizons On-Line Ephemeris and Data System ("Horizons" for short) is a computer program that provides data on the locations, motions, and dynamical parameters of solar-system objects, including the Sun, nine planets, 61 natural satellites, more than 16,000 comets and asteroids, and...

Briefs : Information Technology
Strategies for Optimal Placement of Sensors and Actuators

A paper presents a survey of sensor- and actuator-placement problems from various applications that involve a wide range of engineering disciplines. "Smart" structures that contain sensors (e.g., microphones or strain sensors) and actuators (e.g., loudspeakers or piezoelectric actuators)...

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