Briefs : Physical Sciences
Optical Fourier-Plane Analysis of Suspended Particles

Optical Fourier-plane analysis may prove useful for obtaining statistical data on the densities, sizes, shapes, indices of refraction, and perhaps other properties of particles (particularly, biological cells) suspended in liquids. This concept could potentially be the basis of a new class of...

Briefs : Physical Sciences
Preparing High-Quality Micrographic Samples of Oil Paintings

A technique similar to that of metallography has been devised for preparing cross-sectional micrographic specimens from small samples cut from oil paintings. Art experts at the Cleveland Museum of Art use the technique in their efforts to determine painters’ methods and to verify the...

Briefs : Physical Sciences
Pyrolytic-Graphite Gauges for Measuring Large Heat Fluxes

Gauges made of slugs of pyrolytic graphite with thermocouples em- bedded in them have been invented for use in measuring large, short-duration heat fluxes in hot, highly corrosive environments. These gauges were originally intended for use in combustion chambers of rocket engines; they...

Briefs : Physical Sciences
Wind and Mountain Wave Observations From a Flight Test of a Solar-Powered Airplane

In support of NASA’s Environmental Research Aircraft and Sensor Technology (ERAST) program, flight tests of the Pathfinder solar-electric-powered, remotely piloted aircraft (RPA) were conducted at the Navy’s Pacific Missile Range Facility (PMRF), Barking...

Briefs : Physical Sciences
Electrostatic Systems Keep Dust Off Surfaces

Electrostatic dust- collection systems that comprise wire grids connected to lightweight, low-power high-voltage sources have been invented for preventing the accumulation of dust on surfaces. Intended originally for use in keeping spacecraft solar panels free of dust, these systems could also be used...

Briefs : Materials
Research on Life-Prediction Methods for MMCs— Phase I

A report describes the completed first phase of a NASA/industry cooperative program of research on metal-matrix composites (MMCs) as lightweight, strong, high- temperature-resistant materials for use in future aircraft engines. The first phase of the research included assessment of life-...

Briefs : Information Technology
Wavelet-Based Time-Varying Models of Pilots in Control Loops

A report presents a study of the use of wavelet-based mathematical models to quantify the responses of humans in control loops. The report begins with a review of the traditional representation of manual control responses by use of transfer functions derived from Fourier transforms,...

Briefs : Photonics/Optics
Spectral Region for Laser Isotope Measurements of Gases

A mid-infrared wave-number range has been identified as being useful for laser measurements of CO and CO2 gases that contain various combinations of isotopes of C and O. The isotopic species are 12C16O (common CO), 13C16O,...

Briefs : Photonics/Optics
Reflective Variants of Miniature Microscope Without Lenses

The figure schematically depicts two proposed alternative versions of an instrument that amounts, in effect, to a compact, lightweight optoelectronic microscope that contains no lenses and generates a magnified video image of a specimen. The instrument was described in "Miniature...

Briefs : Photonics/Optics
Fiber-Coupled Microsphere Laser at Wavelength of 1.55 µm

The figure depicts the laboratory setup of an optical-fiber-coupled microsphere laser with an output in the 1.55-µm wavelength band used in some communication systems. This laser offers the obvious advantages of compactness and simplicity. In addition, as consequences of the high...

Briefs : Photonics/Optics
Multiple-Pump Lasers

A conceptually simple, effective scheme for reliable, high-power pumping of neodymium:yttrium aluminum garnet (Nd:YAG) lasers (and perhaps also other solid-state lasers) has been devised. Heretofore, it has been common practice to pump a Nd:YAG crystal by use of a single diode laser. However, diode lasers are not reliable...

Briefs : Electronics & Computers
“Morphing” in Evolutionary Synthesis of Electronic Circuits

A method of automated evolutionary synthesis of electronic circuits has been augmented by a concept called “morphing through fuzzy topologies.” Previous versions of the method provided for the evaluation of “crisp” topologies were precisely specified by open/closed (on/off)...

Briefs : Electronics & Computers
Miniature Fuel Cells for Small, Portable Electronic Devices

Miniature fuel cells in a “flat-pack” configuration are being developed as alternatives to recharge- able batteries in cellular telephones, laptop computers, and other small, portable electronic devices. These fuel cells exploit the electrochemical oxidation of organic fuel (usually...

Briefs : Materials
Internal-Combustion Engines With Ringless Carbon Pistons

Internal-combustion engines would be constructed with cylinders and ringless pistons made of lightweight carbon/carbon composite materials, according to a proposal. This proposal is a logical extension of previous research that showed that engines that contain carbon/carbon pistons with...

Briefs : Electronics & Computers
Mixtrinsic Evolutionary Synthesis of Electronic Circuits

A method of automated synthesis of analog and/or digital electronic circuits involves evolution in both software simulations and hardware. Heretofore, the evolutionary auto- mated synthesis of electronic circuits has been accomplished by use of either software simulations or hardware, but...