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 : Electronics & Computers
Computer System for Collection of Quality-Assurance Data

The Paperless Procedure System (PPS) is a computer-based, semiautomated electronic system for collection and management of quality-assurance data in a large organization. The original version of PPS was designed for use by Kennedy Space Center personnel engaged in inspection tasks during...

Briefs : Electronics & Computers
Overview of Tapered-Slot Antennas

A document presents a comprehensive overview of the technology of tapered-slot antennas and arrays of such antennas. The fundamental operation of tapered-slot antennas is not yet fully understood, and, for lack of established design rules, the designs of these antennas have been based primarily on empirical...

Briefs : Materials
Fiber-Reinforced-Plastic/Concrete Structural Members

Improved concrete structural members such as columns, piers, and piles can be manufactured by incorporating fiber-reinforced-plastic (FRP) exterior shells and FRP interior submembers. The FRP components impart greater compressive, flexural and shear strengths and ductility to a concrete...

Briefs : Materials
Creep-Resistant Ceramic Composite for High-Temperature Use

A low-density, creep-resistant ceramic composite material has been developed as a prototype of such materials for use at high temperatures in the next generation of aircraft engines. The material consists of Nextel (or equivalent) ceramic fibers in a matrix that is, itself, a composite...

Briefs : Materials
Nearly Isotropic Resin-Transfer-Molded Composites

Nearly isotropic matrix/fiber composite materials can be made quickly and at relatively low cost by resin-transfer molding. The fiber components of these materials are fine, loosely woven, three-dimensional preforms; the matrix components are epoxy or polycyanate resins. With proper tooling,...

Briefs : Mechanical & Fluid Systems
Bidirectional Operating Actuator (BOA)

A generic actuator has been designed to amplify the piezoelectric effect. The Bidirectional Operating Actuator (BOA) amplifies the stroke of a piezoelectric element and reorients it through a kinematic linkage.

Briefs : Electronics & Computers
Automated Vision System Inspects a Large Surface

The figure schematically illustrates an automated electronic vision system that operates in conjunction with a scanning robot to inspect a large surface for damage. In the original application for which the system was developed, the surface comprises the panels of the space shuttle thermal...

Briefs : Robotics, Automation & Control
Micromachined Monopropellant Thrusters

A report proposes monopropellant microthrusters for a new generation of miniature spacecraft with mission lifetimes stretching into years. These thrusters would include micromachined nozzle/chamber assemblies containing microvalves, designed according to emerging concepts of microelectromechanical systems...

Briefs : Electronics & Computers
Control System for Steerable, Rooftop-Mounted Antenna

An excerpt from JPL Document D-12104 presents additional information on the control system of a steerable microwave antenna that is mounted on the roof of a land vehicle and used to communicate with a geostationary satellite. The antenna and control system were described previously in...

Briefs : Electronics & Computers
Fabrication of Arrays of Large Step-Free Regions on Si(100)

When a silicon wafer is cut from an ingot, it is essentially impossible to align the cut perfectly with the crystal structure. Therefore the surface contour of the wafer will be a flat plane on which terraces consisting of additional atomic layers will be scattered. An atomic step will...

Briefs : Materials
Iron-Containing Carbon Materials Made From Graphite Fluoride

Experiments have shown that carbon-based materials containing pure metallic iron, alloys of iron, halides of iron, and/or oxides of iron can be synthesized from precursors of general composition CFx, denoted loosely as graphite fluoride. Typical samples of the product...

Briefs : Electronics & Computers
Reflective Coating System for High-Temperature Vacuum Use

A substrate of nickel coated with a thin layer of silver and further coated with a thin protective layer of silicon dioxide has been found to constitute an optically reflective substrate/coating system that is suitable for use at high temperature in vacuum. This system was developed...

Briefs : Electronics & Computers
Extracting Misalignments of Layers in Microfabricated Devices

Two closely related methods of optical inspection and computation yield data on misalignments between critical features in different layers of microfabricated devices. Examples of such devices containing features in different layers that are required to be aligned with each other...

Briefs : Electronics & Computers
Optoelectronic Oscillators Based on Brillouin Scattering

An improved type of optoelectronic oscillator is based on Brillouin amplification. An oscillator of this type converts light energy into an electro-optical oscillation, typically at a frequency of several gigahertz. It offers several advantages over other electro-optical and over...

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...

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