May 2005

Briefs : Medical
Satellite-Derived Management Zones

The term “satellite-derived management zones” (SAMZ) denotes agricultural management zones that are subdivisions of large fields and that are derived from images of the fields acquired by instruments aboard Earth orbiting satellites during approximately the past 15 years. “SAMZ” also denotes the...

Briefs : Test & Measurement
Simultaneous Conoscopic Holography and Raman Spectroscopy

A new instrument was developed for chemical characterization of surfaces that combines the analytical power of Raman spectroscopy with the three-dimensional topographic information provided by conoscopic holography. The figure schematically depicts the proposed hybrid instrument. The...

Briefs : Physical Sciences
Vacuum Attachment for XRF Scanner

Vacuum apparatuses have been developed for increasing the range of elements that can be identified by use of x-ray fluorescent (XRF) scanners of the type mentioned in the two immediately preceding articles. As a consequence of the underlying physical principles, in the presence of air, such an XRF scanner is...

Briefs : Physical Sciences
Identifying Objects via Encased X-Ray-Fluorescent Materials — the Bar Code Inside

Systems for identifying objects by means of x-ray fluorescence (XRF) of encased labeling elements have been developed. The XRF spectra of objects so labeled would be analogous to the external bar code labels now used to track objects in everyday commerce. In...

Briefs : Physical Sciences
Digital Equivalent Data System for XRF Labeling of Objects

A digital equivalent data system (DEDS) is a system for identifying objects by means of the x-ray fluorescence (XRF) spectra of labeling elements that are encased in or deposited on the objects. As such, a DEDS is a revolutionary new major subsystem of an XRF system. A DEDS embodies the...

Briefs : Electronics & Computers
Improvements of ModalMax High-Fidelity Piezoelectric Audio Device
ModalMax audio speakers have been enhanced by innovative means of tailoring the vibration response of thin piezoelectric plates to produce a high-fidelity audio response. The ModalMax audio speakers are 1 mm in thickness.
Briefs : Electronics & Computers
Long-Range Emergency Preemption of Traffic Lights

A forwarding system could prove beneficial as an addition to an electronic communication and control system that automatically modifies the switching of traffic lights to give priority to emergency vehicles. A system to which the forwarding system could be added could be any of a variety of...

Briefs : Electronics & Computers
High-Efficiency Microwave Power Amplifier

A high-efficiency power amplifier that operates in the S band (frequencies of the order of a few gigahertz) utilizes transistors operating under class-D bias and excitation conditions. Class-D operation has been utilized at lower frequencies, but, until now, has not been exploited in the S band.

Briefs : Manufacturing & Prototyping
Race Car Manufacturer Uses Finite Element Analysis to Simulate Chassis Performance

The monocoque chassis of a Formula 1 race car is a sandwich structure, made of high-performance carbon-epoxy composite face sheets and an aluminum or aramidic honeycomb core. High-modulus and high-strength composites, with aerospace-class toughened epoxy resins,...

Briefs : Information Technology
Applying Standard Interfaces to a Process-Control Language
A method of applying open-operating-system standard interfaces to the NASA User Interface Language (UIL) has been devised.
Briefs : Information Technology
Adaptive Filtering Using Recurrent Neural Networks

A method for adaptive (or, optionally, nonadaptive) filtering has been developed for estimating the states of complex process systems (e.g., chemical plants, factories, or manufacturing processes at some level of abstraction) from time series of measurements of system inputs and outputs. The...

Briefs : Materials
Multifunctional Deployment Hinges Rigidified by Ultraviolet

Multifunctional hinges have been developed for deploying and electrically connecting panels comprising planar arrays of thin-film solar photovoltaic cells. In the original intended application of these hinges, the panels would be facets of a 32-sided (and approximately spherical)...

Briefs : Mechanical & Fluid Systems
Ultrasonic/Sonic Jackhammer

An ultrasonic/sonic jackhammer (USJ) is the latest in a series of related devices, the first of which were reported in “Ultrasonic/Sonic Drill/Corers With Integrated Sensors” (NPO-20856), NASA Tech Briefs, Vol. 25, No. 1 (January 2003), page 38. Each of these devices cuts into a brittle material by means of...

Briefs : Mechanical & Fluid Systems

The term “vortobots” denotes proposed swimming robots that would have dimensions as small as micrometers or even nanometers and that would move in swarms through fluids by generating and exploiting vortices in a cooperative manner. Vortobots were conceived as means of exploring confined or otherwise inaccessible fluid environments:...

Briefs : Mechanical & Fluid Systems
Two SMA-Actuated Miniature Mechanisms

The figures depict two miniature mechanisms actuated by strips made of shape-memory alloy (SMA). A typical SMA is a nickel-titanium alloy known by the trade name “Flexinol” or “Nitinol.” In preparation for a typical application, a suitably sized and shaped piece of an SMA is deformed by a...

Briefs : Mechanical & Fluid Systems
Piezo-Operated Shutter Mechanism Moves 1.5 cm

The figure shows parts of a shutter mechanism designed to satisfy a number of requirements specific to its original intended application as a component of an atomic clock to be flown in outer space. The mechanism may also be suitable for use in laboratory and industrial vacuum systems on Earth for...

Briefs : Mechanical & Fluid Systems
Temperature-Controlled Clamping and Releasing Mechanism

A report describes the development of a mechanism that automatically clamps upon warming and releases upon cooling between temperature limits of ~180 K and ~293 K.

Briefs : Mechanical & Fluid Systems
Fastener Starter

The Fastener Starter is a creative solution to prevent the loss of small fasteners during their installation. This is the only currently available tool that can firmly grip and hold a single screw, bolt, nut, washer, spacer, or any combination of these parts. Other commercially available fastener starters are unable to...

Briefs : Semiconductors & ICs
HEMT Frequency Doubler With Output at 300 GHz

An active frequency doubler in the form of an InP-based monolithic microwave integrated circuit (MMIC) containing a high electron mobility transistor (HEMT) has been demonstrated in operation at output frequencies in the vicinity of 300 GHz. This is the highest frequency HEMT doubler reported to...

Briefs : Semiconductors & ICs
Single-Chip FPGA Azimuth Pre-Filter for SAR

A field-programmable gate array (FPGA) on a single lightweight, low power integrated-circuit chip has been developed to implement an azimuth pre-filter (AzPF) for a synthetic-aperture radar (SAR) system. The AzPF is needed to enable more efficient use of data-transmission and data-processing resources:...

Briefs : Semiconductors & ICs
Alumina or Semiconductor Ribbon Waveguides at 30 to 1,000 GHz

Ribbon waveguides made of alumina or of semiconductors (Si, InP, or GaAs) have been proposed as low-loss transmission lines for coupling electronic components and circuits that operate at frequencies from 30 to 1,000 GHz. In addition to low losses (and a concomitant ability to...

Briefs : Software
Electronic Router

Electronic Router (E-Router) is an application program for routing documents among the cognizant individuals in a government agency or other organization. E-Router supplants a prior system in which paper documents were routed physically in packages by use of paper slips, packages could be lost, routing times were unacceptably...

Briefs : Software
Centralized Planning for Multiple Exploratory Robots

A computer program automatically generates plans for a group of robotic vehicles (rovers) engaged in geological exploration of terrain. The program rapidly generates multiple command sequences that can be executed simultaneously by the rovers. Starting from a set of high-level goals, the...

Briefs : Software
Predicting Flows of Rarefied Gases
DSMC Analysis Code (DAC) is a flexible, highly automated, easy-to-use computer program for predicting flows of rarefied gases — especially flows of upper-atmospheric, propulsion, and vented gases impinging on spacecraft surfaces. DAC implements the direct simulation Monte Carlo (DSMC) method, which is widely...
Briefs : Software
Software Would Largely Automate Design of Kalman Filter
Embedded Navigation Filter Automatic Designer (ENFAD) is a computer program being developed to automate the most difficult tasks in designing embedded software to implement a Kalman filter in a navigation system. The most difficult tasks are selection of error states of the filter and tuning...
Briefs : Software
Autonomous Navigation by a Mobile Robot
ROAMAN is a computer program for autonomous navigation of a mobile robot on a long (as much as hundreds of meters) traversal of terrain. Developed for use aboard a robotic vehicle (rover) exploring the surface of a remote planet, ROAMAN could also be adapted to similar use on terrestrial mobile robots. ROAMAN...
Briefs : Physical Sciences
Spectral Beam Combining Architecture for Diode Laser Bars

A new Spectral Beam Combining (SBC) architecture is currently being developed to address the limitations diode laser bars in applications requiring high output power and excellent beam quality. The architecture features an external resonant cavity with a dispersive element to...

Briefs : Physical Sciences
Vibrating Optical Fibers To Make Laser Speckle Disappear

In optical systems in which laser illumination is delivered via multimode optical fibers, laser speckle can be rendered incoherent by a simple but highly effective technique. The need to eliminate speckle arises because speckle can make it difficult to observe edges and other sharp...

Briefs : Physical Sciences
Adding GaAs Monolayers to InAs Quantum-Dot Lasers on (001) InP

In a modification of the basic configuration of InAs quantum-dot semiconductor lasers on (001)lnP substrate, a thin layer (typically 1 to 2 monolayer thick) of GaAs is incorporated into the active region. This modification enhances laser performance: In particular, whereas it has...

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