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 : Materials
Evaluation of Additives to PFPEs in Boundary Lubrication

A report describes experiments on the wear-reducing performances of six additives to perfluoropolyether (PFPE)-based fluids in the boundary-lubrication regime. The additives were a phosphate, a thiophosphate, a β-diketone, a benzothiazole, an amide/thiol, and a sulfite. Each additive was...

Briefs : Mechanical & Fluid Systems
Electromagnetic Smart Washer for Detecting Bolthole Cracking

Engineers have designed a new device, called the Smart Washer, that can electromagnetically detect bolthole cracks in metal structures. The device is a metal washer that contains a wire coil embedded onto the bottom surface of the washer. An alternating current drives this coil and...

Briefs : Mechanical & Fluid Systems
Deflection of Circular Membrane Under Differential Pressure

Equations have been derived to fill a gap in previously published standard collections of stress-and-strain formulas: These are equations for deflection of a thin circular membrane that is clamped rigidly around its periphery and subjected to differential pressure. Related equations...

Briefs : Electronics & Computers
Exploiting Brillouin Scattering in Analog Signal Processing

Stimulated Brillouin Scattering (SBS) in optical fibers can be exploited to obtain frequency conversion with amplification and frequency-selective amplification in photonic signal-transmission and signal-processing systems. SBS has been found to be particularly useful in photonic...

Briefs : Electronics & Computers
Impedance-Based Cable Tester

The figure illustrates the major functional blocks of an impedance-based cable-testing apparatus that can locate an open or short circuit in a cable. There is no need to disconnect the cable from all other equipment in preparation for a test – an advantage in a system in which cable connections are located in...

Briefs : Electronics & Computers
Low-Frequency Signal-Pickup Cable Tester

A cable-testing apparatus has been designed for use in detecting a short or open circuit in a cable, subject to a special frequency requirement as explained in the next paragraph. This cable tester is based on the injection of a signal at one end of the cable and the use of a pickup coil placed adjacent...

Briefs : Materials
Improved Nonlinear Mathematical Model of Viscoelasticity

An improved nonlinear mathematical model is being developed for use in predicting the complex, time-varying stress-and-strain behaviors of viscoelastic materials. The development of this model is prompted by (1) the lack of success of older constitutive mathematical models that contain...

Briefs : Materials
Computation of Progressive Fracture in a Bolted Laminate

A method of computational simulation of progressive fracture in composite-material (matrix/fiber) structural components has been developed. This method does not involve stress-intensity factors or fracture toughnesses. Instead, it involves consideration of the mechanics of the composite...

Briefs : Electronics & Computers
Computing Limiting Voltages vs. Temperatures for Ni/Cd Cells

Curves of limiting voltage (V) as a function of temperature (T) for nickel/cadmium cells and batteries can be computed by use of a mathematical cell model based on first principles. Such curves ("V/T curves" for short) are needed as guides to rapid full charging without overcharging....

Briefs : Electronics & Computers
Lightning Detection and Ranging System

The Lightning Detection and Ranging (LDAR) system is a network of lightning-monitoring stations at Kennedy Space Center. The LDAR system contains equipment for measuring and indicating the three-dimensional locations and times of lightning flashes that have occurred within distances up to tens of...

Briefs : Robotics, Automation & Control
Making Fuels Onboard for Power Bursts in Exploratory Robots

In-situ resource utilization (ISRU) equipment would be incorporated into remotely controlled exploratory robots, according to a proposal, to generate fuels and oxidizers to extend operational ranges and to provide occasional bursts of power for actions like drilling into the ground,...

Briefs : Mechanical & Fluid Systems
Rigid, Insulating Support for Cryogenic Component

A structure provides rigid support for a cryogenic component but transmits minimal heat. The structure includes two beams of Invar (or equivalent low-thermal expansion iron/nickel alloy) that are held in alignment, without touching each other, by pretensioned strands of KevIar® (or...

Briefs : Materials
Regenerable Foam Suppressor

A foam suppressor removes soap and other foaming agents from a stream of wastewater that is being treated electrolytically. This wastewater is a combination of laundry, hygiene, and urine wastewater. It is desirable to prevent foaming because foaming reduces, by about 15 percent, the efficiency of electrooxidation of...

Briefs : Photonics/Optics
Microburst Automatic Detection (MAD™)

The portable, easily expandable Microburst Automatic Detection (MAD) system can dramatically improve aviation safety. Mimicking the reasoning of a human observer on the lookout for weather hazards, MAD assesses such hazards quickly while avoiding human weaknesses such as fatigue. Timely alerts to pilots...

Briefs : Electronics & Computers
In-Process Monitoring and Analysis of Thermal-Spray Processes Using Machine Vision

The LaserStrobe Optical Probe is an advanced laser-augmented video-imaging system that observes and measures particle behavior in the harsh environment of a plasma-spray chamber. The need for a reliable diagnostic and feedback control system during thermal-spray...

Briefs : Robotics, Automation & Control
Solar-Powered Aerobots With Power-Surge Capabilities

Advanced aerobots that would be powered by solar photovoltaic batteries and that would be capable of storing energy for occasional operation during short intervals at power levels far beyond those of the photovoltaic batteries have been proposed. Aerobots are robotic balloon-buoyed airborne...

Briefs : Physical Sciences
Combination of Cryotrapping and SPME for GC/MS Analysis

An improved process has been devised for acquiring and preparing trace amounts of airborne organic compounds for analysis by a gas chromatograph and mass spectrometer (GC/MS). A sample of air is passed through a cryotrap, where organic compounds and water vapor condense on the wall of a...

Briefs : Mechanical & Fluid Systems
Multichannel Ultrasonic-Bolt-Tension-Gauge System

An improved system for measuring tensions in multiple bolts is based on the usual measurement of the times of propagation of ultrasonic waves along the bolts, but the quantities measured and the method of processing the measurement data differ from those of conventional ultrasonic bolt-tension...

Briefs : Photonics/Optics
Autostereoscopic Displays for Scientific Visualization

Many types of scientific images and data are complex and are easier to interpret when observed in three dimensions. This is especially true for information presented visually in the form of multiparameter graphs and tables, as well as for images of physical events, such as turbulent flows....

Briefs : Physical Sciences
Measuring Velocity of Ice by SRI Using Ascending and Descending Passes

A method of satellite radar interferometry (SRI) enables the remote measurement of three-dimensional velocities of ice flow over large areas of glaciers. At present, ice-flow velocities are measured primarily in situ by use of the Global Positioning System (GPS) in a...

Briefs : Physical Sciences
Determining Characteristics of Wind-Borne Particles

A small, robust, lightweight, low-power-consumption instrumentation system has been proposed for determining the kinetic energies, masses, and other parameters of wind-borne particles. Originally intended for use in future exploration of Mars, the system might also prove useful on Earth for...

Briefs : Electronics & Computers
Computation of Characteristics of a Helical TWT Slow-Wave Circuit

A computational study has been performed to show that one can accurately compute the cold-test electromagnetic characteristics of the helical slow-wave circuit of a traveling-wave tube (TWT).

Briefs : Physical Sciences
Electrochemical Monitoring of Hydrazine in Air

An instrumentation system monitors ambient air to determine whether hydrazine vapor is present in sufficient concentration to be harmful to humans or equipment. The system can measure hydrazine concentrations as low as 10 parts per billion (ppb); this level of concentration is denoted the threshold...

Briefs : Physical Sciences
Electrostatic Dispersion of Fuel Drops To Reduce Soot

Electrostatic dispersion of drops of sprayed liquid fuel has been proposed as a technique for reducing the amount of soot formed during burning of the fuel. It is necessary to disperse fuel drops in order to reduce local concentrations of fuel-rich vapors, because such concentrations favor...

Briefs : Information Technology
System for Locating Objects of Interest in Image Data Bases

A trainable software system known as JARtool 2.0 has been developed to help scientists find localized objects of interest ("target objects") in image data bases. A human expert implicitly trains the system by using a graphical user interface (see figure) to circle all examples of the...

Briefs : Electronics & Computers
Glove Senses Angles of Finger Joints

A glove has been instrumented to sense the angles of finger joints via the electrical resistances of strips of an electrically conductive elastomer on the backs of the fingers, including the thumb (see figure). The conductive elastomer is a urethane-based synthetic rubber filled with conductive carbon...

Briefs : Photonics/Optics
Line-Focus Photovoltaic Module With Solid Secondary Optics

The figure illustrates aspects of a lightweight, relatively inexpensive solar photovoltaic module suitable for use on Earth or in outer space in conjunction with at least a single-axis Sun-tracking apparatus. The module contains line-focus primary Fresnel lenses that act in conjunction...

Briefs : Photonics/Optics
Endoscopic Shearography Inspection

An imaging method to detect flaws in composite pressure vessels used in the aerospace industry has been developed. Solid-rocket-motor casings and fuel or oxidizer tanks for liquid rocket motors can now be evaluated with the endoscopic shearography inspection device.

Briefs : Physical Sciences
Stereoscopic, Three-Dimensional PIV With Fuzzy Inference

An all-electronic digital particle-image velocimetry (PIV) system has been developed for use in measuring three-dimensional velocities at numerous points throughout a plane of interest in a supersonic flow. This system includes two high-resolution charge-coupled-device (CCD) video cameras...

Briefs : Electronics & Computers
Discriminator-Stabilized Superconductive/Ferroelectric Oscillator

An oscillator circuit that contains superconductive and ferroelectric resonator elements is undergoing development. This circuit is designed to serve as a frequency-locked local oscillator in a communication system in which digital data are conveyed via phase modulation on a...

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