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 : Physical Sciences
New Technique Improves Cirrus Cloud Characterization

A new technique for retrieving cirrus properties from radiometric measurements at submillimeter wavelengths has been developed. The technique can accurately measure the amount of ice present in cirrus clouds, determine the median crystal size, and constrain crystal shape. The retrieval...

Briefs : Information Technology
Maximum-Likelihood Template Matching

An improved algorithm for detecting gray-scale and binary templates in digitized images has been devised. The greatest difference between this algorithm and prior template-detecting algorithms stems from the measure used to determine the quality or degree of match between a template and given portion of an...

Briefs : Information Technology
Fast Algorithms and Circuits for Quantum Wavelet Transforms

Fast algorithms and the first complete and efficient circuits for implementing two quantum wavelet transforms have been developed in theory. The significance of this development within the overall development of quantum computing is the following: In principle, the algorithms and...

Briefs : Physical Sciences
Study of Inertial and Gravitational Masses of a Boson

A report presents a theoretical study of the relationship between the inertial mass (mi) and gravitational mass (mg) of a self-interacting neutral scalar boson in a heat bath. The question of whether these masses differ arises in modern physics. In quantum field theory, the mass of a particle...

Briefs : Physical Sciences
Metal/Dielectric Color Filters for Flat Panel Displays

A report expands on the proposal described in “Low-Absorption Color Filters for Flat Panel Display Devices” (NPO-20435) NASA Tech Briefs, Vol. 23, No. 12 (December 1999), page 34. To recapitulate: The dye pixel color filters in a conventional liquid-crystal or other display device would...

Briefs : Physical Sciences
Multiphase-Flow Model of Fluidized-Bed Pyrolysis of Biomass

A report presents additional information about the subject matter of “Model of Pyrolysis of Biomass in a Fluidized- Bed Reactor” (NPO-20708) NASA Tech Briefs, Vol. 25, No. 6 (June 2001), page 59. The model is built on equations for the dynamics of three components — gas, sand, and...

Briefs : Electronics & Computers
Vision-Only Operator Interface for a Robotic Manipulator

A system of electronic hardware and software has been developed as an experimental prototype of a visual interface between a human operator and a possibly remote one-arm anthropomorphic robotic manipulator. The system is denoted, more specifically, as a visiononly operator interface to...

Briefs : Software
Software for Geometric Calibration of Video Cameras

A software library and set of programs largely automate the geometric calibration of video cameras. Developed especially for robotic vision systems, this software generates the information needed to determine the three-dimensional (3D) positions of objects that appear in two- dimensional (2D)...

Briefs : Mechanical & Fluid Systems
Motor Drive for Multiple Horizontally Rotating Bioreactors

The figure depicts a mechanism that is capable of simultaneously rotating as many as six disposable bioreactor chambers about horizontal axes. The particular bioreactor chambers for which this mechanism is designed are high-aspect-ratio vessels (HARVs), which are round cylindrical...

Briefs : Mechanical & Fluid Systems
Tip Fences for Reduction of Lift- Generated Airframe Noise

Tip fences have been invented to reduce the noise generated in the airflows about the high-lift systems (the flaps and slats) of airplane wings. Tip fences also afford an important secondary benefit by increasing lift-todrag ratios.

Briefs : Photonics/Optics
Crystalline Organic Films for Optical Applications

Cells that contain thin, single-crystal films of photoresponsive organic materials [e.g., meta-nitroaniline (m-NA)] have been invented for use as nonlinear optics and especially as second-harmonic generators. In comparison with crystals of potassium dihydrogen phosphate (KDP) that have been...

Briefs : Photonics/Optics
Optoelectronic Oscillator With Low Acceleration Sensitivity

An optoelectronic oscillator with a nominal operating frequency of 11.763 GHz has been designed and constructed to demonstrate a technique for reducing the sensitivity of the operating frequency to acceleration. Optoelectronic oscillators in general exhibit low sensitivity to...

Briefs : Photonics/Optics
Apparatus Measures X-Ray Diffraction and Fluorescence

The figure depicts an apparatus for measuring x-ray diffraction (XRD) and/or x-ray fluorescence (XRF) in a specimen of material. The specimen could be, for example, a standard XRD powder sample of a mineral, the elemental composition of which one seeks to identify. It is common practice to...

Briefs : Photonics/Optics
Fluorescent Dyes for Two-Photon Microscopy

A proposed program of research would be oriented toward the development of fluorescent dyes for use in two-photon microscopy. Two-photon microscopy and its predecessor, one-photon microscopy, are variants of fluorescence microscopy, which has become a major technology for biological and physical...

Briefs : Photonics/Optics
Critical Composition Buffering for Growing InxGa1-xAs on InP

A method of growing lattice-mismatched InxGa1-xAs epitaxial layers on InP substrates using intermediate buffer layers of InAsyP1-yhas been invented to improve the performance of...

Briefs : Electronics & Computers
Real-Time-Programmable Reconfigurable-Vision Active-Pixel Sensors

Active-pixel integrated-circuit image sensors that can be programmed in real-time to effect artificial reconfigurable vision on demand have been developed and demonstrated. In imitation of a natural eye, the image sensor is designed to offer high resolution in a small region of...

Briefs : Mechanical & Fluid Systems
Instrumented Bolt Measures Bending Moments Within Itself

The Ultrabend bolt is a specially designed bolt instrumented with strain gauges (see figure) that are connected into twin Wheatstone-bridge circuits. The geometric arrangement of the strain gauges is such that by suitable electrical switching of the Wheatstone-bridge circuits, these...

Briefs : Physical Sciences
Tiger Fibers for Enhanced Optical Sensing of Volatiles

Improved fiber-optic transducers, denoted tiger fibers, have been proposed for sensing volatile compounds. Tiger fibers are so named because, as described below, their sensitive portions would be coated with periodically alternating stripes of different polymers, reminiscent of a tiger’s...

Briefs : Physical Sciences
Using Laser Diodes to Characterize Force and Pressure Sensors

A proposed method of characterizing microphones and other pressure and force sensors would exploit the temporally varying forces of impingement of amplitude-modulated light beams from inexpensive laser diodes. What makes the method likely to be practical is the surprising fact that...

Briefs : Mechanical & Fluid Systems
Improved Piezoelectrically Actuated Microvalve

Figure 1. The Previous Version of the Valve, like the present version, was opened by applying a voltage that caused the piezoelectric actuator to contract slightly.Efforts are underway to implement an improved design of the device described in "Normally Closed, Piezoelectrically Actuated Microvalve"...

Briefs : Electronics & Computers
Improved Continuity and Short-Circuit Tester

A relatively simple test circuit immediately and automatically provides indications of (1) the continuity (or the lack thereof) of the wires of a two-wire cable, plus (2) a short circuit (if any) between the wires. In the case of a coaxial cable, one of the wires can be the shield, the other wire, or...

Briefs : Electronics & Computers
Automated Detection of Streaks in Rocket-Engine Plumes

A high-speed observer (HSO) system comprising a high-frame-rate digital video camera and a high-speed computer that processes the camera output has been developed for use in monitoring the exhaust plume of the space shuttle main engine (SSME) during tests. The HSO system is designed to...

Briefs : Information Technology
Software for Analyzing Root Causes of Process Anomalies

Root Cause Analysis (RoCA) is a computer program that assists analysts in understanding the root causes of process anomalies. As used here, “process anomalies” includes incidents that have caused, or that can potentially cause, injuries to personnel, damage to facilities, abnormal...

Briefs : Mechanical & Fluid Systems
Program Computes Pointing Corrections for a Radiotelescope

TLC is a computer program that determines corrections for radiotelescopepointing errors associated with tilts and elastic deformations. These errors occur because for rotation in azimuth, a radiotelescope is mounted on wheels that move on a circular track that deviates from perfect...

Briefs : Information Technology
Ex — Software for Numerical Computation in Native Oberon

“Ex” is the name of a library of software modules from which one can rapidly develop prototype or production versions of efficient numerical-computation application programs in the Native Oberon programming environment. Mathematical constructs that can be represented and processed by...

Briefs : Materials
Annealing for Tailoring Au/GaN Schottky-Barrier Height

Annealing has been found to be an effective means of tailoring the height of a Schottky barrier between gold and gallium nitride. This finding offers promise for the development of improved metal contacts on GaN semiconductors. Heretofore, the commercialization of GaN semiconductor devices...

Briefs : Materials
Ceramics Made From Wood

The term “ecoceramics” (a contraction of “environment-conscious ceramics”) denotes a class of ceramics made partly from wood-based products, which can include natural wood, sawdust, cardboard, and/ or paper. In addition to the environmental advantage of renewability of the carbonaceous ingredients, the concept of...

Briefs : Mechanical & Fluid Systems
Lightweight, Low-Backlash Robot Wrist With Epicyclic Drive

A unique lightweight wrist with three degrees of rotational freedom has been developed as a prototype of wrists for future anthropomorphic robots that would perform a variety of tasks on Earth and in outer space. The three degrees of freedom (two rolling, one bending) intersect at the...

Briefs : Mechanical & Fluid Systems
Ice-Melting Probe Using Steam and Jets of Hot Water

An improved probe has been proposed for burrowing vertically into ice for scientific exploration of polar icecaps, glaciers, and the like. The predecessor of the improved probe is a Philbert probe, which contains an electric heater to melt the ice in contact with it and thereby make it descend...

Briefs : Manufacturing & Prototyping
Two Techniques for Removing Core-Drill Debris

Two alternative techniques make it possible to remove core-drill debris more rapidly and efficiently than was previously possible. Either technique is a vast improvement over the prior art. For industries in which ultrasonic core drills are used, these two techniques are expected to result in savings...