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Briefs: Physical Sciences
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 model...
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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...
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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 the...
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 the...
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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. In...
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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...
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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 and...
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
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...
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Briefs: Medical
The efficiencies and thus the brightnesses of flat-panel projectors based on liquid-crystal devices (LCDs) and digital mirror devices (DMDs) would be increased by the combination of a...
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Briefs: Materials
Since its invention in 1948, the transistor has revolutionized everyday life. The electronics revolution is based on miniaturization of transistors; smaller transistors are faster, and...
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Briefs: Aerospace
NASA’s F-15B #836 is a two-seat version of the F-15, which is a high-performance, supersonic, all-weather fighter airplane. The F-15B is used as a test-bed aircraft for a wide variety of...
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Briefs: Medical
An improved method of sterilizing petri-dish spreaders and a spreader design to implement the method have been developed. In comparison with the conventional methods of sterilizing...
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Briefs: Medical
Quantifying Microbial Diversity Through Dilution/Extinction
A method of relatively easily, rapidly, and inexpensively quantifying the structural diversity of a multiple-species community of micro-organisms is based on the rate of extinction of phenotypic traits across a dilution gradient of a sample of the community. In this context, the concept of...
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 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...
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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: Materials
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 be...
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: Materials
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...
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Briefs: Photonics/Optics
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 these...
Briefs: Medical
An x-ray photogrammetric technique for minimally invasive measurement of displacements in muscles, limbs, and organs is undergoing development. This technique could be alternative or...
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Briefs: Medical
The figure depicts the Biomass Production System (BPS), which is an advanced system that provides controlled conditions for growing, manipulating, sampling, and harvesting plants in...
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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 the...
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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,...
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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...
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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...
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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...
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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 thermal...

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