July 2005

Briefs : Electronics & Computers
Hexagonal and Pentagonal Fractal Multiband Antennas

Multiband dipole antennas based on hexagonal and pentagonal fractals have been analyzed by computational simulations and functionally demonstrated in experiments on prototypes. These antennas are capable of multiband or wideband operation because they are subdivided into progressively smaller...

Briefs : Electronics & Computers
Power Divider for Waveforms Rich in Harmonics

A method for dividing the power of an electronic signal rich in harmonics involves the use of an improved divider topology. A divider designed with this topology could be used, for example, to propagate a square-wave signal in an amplifier designed with a push-pull configuration to enable the...

Briefs : Electronics & Computers
High-Power Fiber Lasers Using Photonic Band Gap Materials

High-power fiber lasers (HPFLs) would be made from photonic band gap (PBG) materials, according to the proposal. Such lasers would be scalable in the sense that a large number of fiber lasers could be arranged in an array or bundle and then operated in phase locked condition to generate a...

Briefs : Electronics & Computers
Circuit Indicates That Voice-Recording Disks Are Nearly Full

A remote alarm circuit provides visible and audible signals to indicate that there is little unused space left on magnetic and optical tracks on disks used to record voice signals in a group of three multichannel voice recorders. In the particular application for which the remote alarm...

Briefs : Electronics & Computers
Quantifying Traversability of Terrain for a Mobile Robot

A document presents an updated discussion on a method of autonomous navigation for a robotic vehicle navigating across rough terrain. The method at an earlier stage of development was described in “Navigating a Mobile Robot Across Terrain Using Fuzzy Logic” (NPO-21199), NASA Tech...

Briefs : Electronics & Computers
Software-Reconfigurable Processors for Spacecraft

A report presents an overview of an architecture for a software-reconfigurable network data processor for a spacecraft engaged in scientific exploration. When executed on suitable electronic hardware, the software performs the functions of a physical layer (in effect, acts as a software radio in...

Briefs : Electronics & Computers
SCB Quantum Computers Using iSWAP and 1-Qubit Rotations

Units of superconducting circuitry that exploit the concept of the single-Cooper-pair box (SCB) have been built and are undergoing testing as prototypes of logic gates that could, in principle, constitute building blocks of clocked quantum computers. These units utilize quantized charge...

Briefs : Semiconductors & ICs
Multifunctional Logic Gate Controlled by Supply Voltage

The figure is a schematic diagram of a complementary metal oxide/semiconductor (CMOS) electronic circuit that functions as a NAND gate at a power-supply potential (Vdd) of 3.3 V and as NOR gate for Vdd = 1.8 V. In the intermediate Vdd range of 1.8 to 3.3 V,...

Briefs : Semiconductors & ICs
Multifunctional Logic Gate Controlled by Temperature

The figure is a schematic diagram of a complementary metal oxide/semiconductor (CMOS) electronic circuit that has been designed to function as a NAND gate at a temperature between 0 and 80 °C and as a NOR gate at temperatures from 120 to 200 °C. In the intermediate temperature range of 80 to...

Briefs : Mechanical & Fluid Systems
Variable-Pressure Washer

The variable-pressure washer (VPW) is a proposed device that is so named because (1) it would play the role similar to that played by an ordinary washer, except that (2) the clamping pressure applied by it would vary with either circumferential or radial position. In a typical contemplated application, the radially...

Briefs : Mechanical & Fluid Systems
Rotating Desk for Collaboration by Two Computer Programmers

A special-purpose desk has been designed to facilitate collaboration by two computer programmers sharing one desktop computer or computer terminal. The impetus for the design is a trend toward what is known in the software industry as extreme programming — an approach intended to...

Briefs : Software
Selecting Data From a Star Catalog

MCDUMP is a computer program that selects data from the SKYMAP SKY2000 Master Star Catalog — a database about 150 MB in size, stored on a computer hard drive.

Briefs : Software
Update on Rover Sequencing and Visualization Program

The Rover Sequencing and Visualization Program (RSVP) has been updated. RSVP was reported in "Rover Sequencing and Visualization Program" (NPO-30845), NASA Tech Briefs, Vol. 29, No. 4 (April 2005), page 38. To recapitulate: The Rover Sequencing and Visualization Program (RSVP) is the software...

Briefs : Software
CSAM Metrology Software Tool

CSAM Metrology Software Tool (CMeST) is a computer program for analysis of false-color CSAM images of plastic-encapsulated microcircuits. ("CSAM" signifies C-mode scanning acoustic microscopy.) The colors in the images indicate areas of delamination within the plastic packages. Heretofore, the images have been...

Briefs : Manufacturing & Prototyping
Solid Freeform Fabrication of Composite-Material Objects

Composite solid freeform fabrication (C-SFF) or composite layer manufacturing (CLM) is an automated process in which an advanced composite material (a matrix reinforced with continuous fibers) is formed into a freestanding, possibly complex, three-dimensional object. In CLM, there is no...

Briefs : Manufacturing & Prototyping
Improvements in Fabrication of Sand/Binder Cores for Casting

Three improvements have been devised for the cold-box process, which is a special molding process used to make sand/binder cores for casting hollow metal parts. These improvements are:

Briefs : Mechanical & Fluid Systems
Magnetically Attached Multifunction Maintenance Rover

A versatile mobile telerobot, denoted the magnetically attached multifunction maintenance rover (MAGMER), has been proposed for use in the inspection and maintenance of the surfaces of ships, tanks containing petrochemicals, and other large ferromagnetic structures. As its name suggests, this...

Briefs : Physical Sciences
Improved Electrolytic Hydrogen Peroxide Generator

An improved apparatus for the electrolytic generation of hydrogen peroxide dissolved in water has been developed. The apparatus is a prototype of H2O2 generators for the safe and effective sterilization of water, sterilization of equipment in contact with water, and other...

Briefs : Physical Sciences
Gauges for Highly Precise Metrology of a Compound Mirror

Three optical gauges have been developed for guiding the assembly and measuring precisely the reflecting surfaces of a compound mirror that comprises a corner-cube retroreflector glued in a hole on a flat mirror. In the specific application for which the gauges were developed, the compound...

Briefs : Physical Sciences
Verifying the Safety of a Radioactive Waste Container With Simulation Software

As part of decommissioning the U.S. Department of Energy (DOE) Hanford Site — an inactive nuclear facility in southeastern Washington — a contaminated apparatus called a glovebox (a steel isolation chamber with built-in gloves that allow personnel to remotely...

Briefs : Physical Sciences
Efficient Computational Model of Hysteresis

A recently developed mathematical model of the output (displacement) versus the input (applied voltage) of a piezoelectric transducer accounts for hysteresis. For the sake of computational speed, the model is kept simple by neglecting the dynamic behavior of the transducer. Hence, the model applies to...

Briefs : Physical Sciences
High Peak Power Fiber Amplifiers Operating at Eye-Safe Wavelengths

Recent advances in fiber technology have enabled a dramatic increase in the power delivered from fiber based amplifiers and lasers. This is particularly true at the 1060-nm wavelength where ytterbium (Yb)-doped fibers operate, with state-of-the-art peak powers now approaching 1...

Briefs : Physical Sciences
Improved Thermal Matching of Materials for Hermetic Optical Windows

A family of iron-nickel and ironnickel- cobalt alloys made using metal injection technology (MIT) has been designed to match the coefficient of thermal expansion (CTE) of select optical glass materials more closely than commonly available wrought alloys of similar composition....

Briefs : Physical Sciences
Thin-Film Resistance Heat-Flux Sensors

Thin-film heat-flux sensors of a proposed type would offer advantages over currently available thin-film heat flux sensors. Like a currently available thin-film heat-flux sensor, a sensor according to the proposal would be based on measurement of voltages related to the temperatures of thin metal films on...

Briefs : Materials
More About Arc-Welding Process for Making Carbon Nanotubes

A report presents additional information about the process reported in "Manufacturing High-Quality Carbon Nanotubes at Lower Cost"; (GSC-14601) NASA Tech Briefs, Vol. 28, No. 9 (September 2004), page 62. To recapitulate: High-quality batches of carbon nanotubes are produced at...

Briefs : Physical Sciences
Controlling Laser Spot Size in Outer Space

Three documents discuss a method of controlling the diameter of a laser beam projected from Earth to any altitude ranging from low orbit around the Earth to geosynchronous orbit. Such laser beams are under consideration as means of supplying power to orbiting spacecraft at levels of the order of tens...

Briefs : Electronics & Computers
Crane-Load Contact Sensor

An electronic instrument has been developed as a prototype of a portable crane-load contact sensor. Such a sensor could be helpful in an application in which the load rests on a base in a horizontal position determined by vertical alignment pins (see Figure 1). If the crane is not positioned to lift the load precisely...

Briefs : Information Technology
Ontology-Driven Information Integration

Ontology-driven information integration (ODII) is a method of computerized, automated sharing of information among specialists who have expertise in different domains and who are members of subdivisions of a large, complex enterprise (e.g., an engineering project, a government agency, or a business). In...

Briefs : Sensors/Data Acquisition
Optical Sensing of Combustion Instabilities in Gas Turbines

In a continuing program of research and development, a system has been demonstrated that makes high-speed measurements of thermal infrared radiance from gas-turbine engine exhaust streams. When a gas-turbine engine is operated under conditions that minimize the emission of pollutants,...