Briefs: Physical Sciences
A project is underway in the Flight Loads Laboratory (FLL) at Dryden Flight Research Center to reduce the uncertainties in heat-flux measurements. The impetus for this project is...
Briefs: Photonics/Optics
A technique for projecting holographic images to make both still and moving three-dimensional displays is undergoing development. Unlike older techniques based on stereoscopy to give...
Briefs: Physical Sciences
An electrometer developed for measuring the triboelectric responses of soils on Mars is also potentially useful on Earth for identifying some materials via their triboelectric responses....
Briefs: Research Lab
Characteristics of Supercritical Transitional Mixing Layers
This report describes a study of threedimensional, temporal mixing layers between different fluids initially flowing at different velocities under supercritical conditions. The study involved direct numerical simulations by use of a validated mathematical model of high-pressurefluid...
Briefs: Physical Sciences
Infrared CO2 Sensor With Built-In Calibration Chambers
A proposed infrared CO2 sensor, operated in conjunction with suitable readout, data-processing, and control circuitry, could be calibrated repeatedly during operation to compensate for changes in sensor response induced by such phenomena as aging and changes in temperature. The...
Briefs: Physical Sciences
Solid-State Potentiometric CO Sensor
A solid-state sensor was developed that measures the concentrations of one or more gases of interest in a mixture of gases. This simple solid-state sensor produces a voltage signal that is sensitive to CO concentration from percent to ppm (parts per million) levels. It was intended originally for use in...
Briefs: Physical Sciences
Cold Flow Calorimeter
The cold flow calorimeter is an apparatus for measuring a possibly rapidly varying heat-transfer coefficient on a surface. The cold flow calorimeter includes (1) a small strain gauge bonded to a small, thin steel shim that is placed on the surface of interest and (2) a circuit that controls the electric power supplied to...
Briefs: Physical Sciences
A relatively inexpensive Sun sensor for determining the absolute heading of planetary rovers to within ± 3° using a monochrome charge-coupled device (CCD) camera is presented....
Briefs: Physical Sciences
An optical absorbance cell that offers a selection of multiple optical path lengths has been developed as part of a portable spectrometric instrument that measures absorption spectra of small...
Briefs: Research Lab
A mathematical model has been developed for use in analyzing the dynamics of an isothermal, non-chemically-reacting mixture of particles in a bubbling fluidized bed. Although the...
Briefs: Physical Sciences
High-throughput, non-imaging, secondary concentrating optics that utilize refraction and total internal reflection are undergoing development for use in conjunction with advanced...
Briefs: Physical Sciences
Improved electrochemical systems for generating ozone (in gaseous form and/or dissolved in water) have been invented for use in disinfection and in industrial processes in which the...
Briefs: Physical Sciences
Quantum Mechanics of Harmonic Oscillator in External Fields
A report presents a theoretical study of a harmonic oscillator in homogeneous or nonhomogeneous externally applied electric and/or gravitational fields. The standard quantum-mechanical formalism for a simple harmonic oscillator, starting with the Hamiltonian and the associated creation...
Briefs: Physical Sciences
Effect of Gravitation on Noninteracting Trapped Fermions
A report presents a theoretical study of the thermodynamics of an ultralow-temperature gas of fermions that interact with a gravitational field and with an externally imposed trapping potential but not with each other. The gravitational field is taken to define the z axis and the trapping...
Briefs: Physical Sciences
Solar Simulator for a Portable Solar-Absorptance Instrument
A special-purpose solar simulator includes (1) a tungsten lamp that serves as a gray-body radiator with a temperature of 3,200 K and (2) a mosaic of filters such that the filtered lamp output has the same normalized spectral irradiance as that of sunlight outside the atmosphere of the...
Briefs: Physical Sciences
A small, lightweight, low-power instrument, denoted a proton-transferreaction/ ion-mobility spectrometer (PTR-IMS) has been developed for detecting airborne organic compounds at...
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: Research Lab
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: Physical Sciences
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...
Briefs: Sensors/Data Acquisition
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: Physical Sciences
DNS of a Supercritical H₂/O₂ Mixing Layer
This report discusses direct numerical simulations (DNS) of a mixing layer between supercritical flows of oxygen and hydrogen. The governing conservation equations were those of fluctuation- dissipation (FD) theory, in which low-pressure typical transport properties (viscosity, diffusivity and...
Briefs: Physical Sciences
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...
Briefs: Physical Sciences
Thin-film devices that comprise heaters in combination with thermocouples have been developed for measuring flow velocities extremely close to solid surfaces, at several distances from...
Briefs: Physical Sciences
An improved formulation of equations of flow of a general gas mixture includes consistent boundary conditions that are applicable to real gases. An analysis of prior formulations,...
Briefs: Physical Sciences
Small instrumented, free-flying (unpowered) rotary aircraft have been proposed for use in gathering scientific data from hazardous or inaccessible terrain on remote planets as well as on Earth. These aircraft...
Briefs: Physical Sciences
A proposed improved balloon system for carrying scientific instruments in the stratosphere would include a lightweight, ambient-pressure helium balloon and a vented infrared...
Briefs: Physical Sciences
Direct methanol fuel cells that would function with aerosol feed (instead of all-gas or all-liquid feed) have been proposed. As explained below, aerosol feed would afford the advantages of liquid...
Briefs: Physical Sciences
A highly sensitive, low-power, low-noise multifunctional active-excitation spectral analyzer (MAESA) that would span the wavelength range of 0.5 to 2.5 µm and would operate near room...
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