SEARCH · Search NASA
Results for “wood development”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Design of test specimens and procedures for generating material properties of Douglas fir/epoxy laminated wood composite material: With the generation of baseline data at two environmental conditions
In support of the design of wind turbine generator airfoils/blades utilizing Douglas Fir/West System Epoxy laminated composite material, a program was undertaken to define pertinent material properties utilizing small scale test specimens. Task 1 was the development of suitable monotonic tension, compression, short beam shear and full reversed cyclic specimen designs and the companion grips and testing procedures. Task 2 was the generation of the material properties at two environmental conditions utilizing the specimens and procedures developed in Task 1. The monotonic specimens and procedures generated results which compare favorably with other investigators while the cyclic results appear somewhat conservative. Adding moisture and heat or scarf joints degraded the monotonic performance but had a more nebulus effect with cyclic loading.
Dynamic delta method for trace gas analysis
Method has been developed in which measurements are made only over viscous flow range, eliminating fractionation before the molecular leak and problems due to surface elution.
Developing mass spectrometric techniques for boundary layer measurement in hypersonic high enthalpy test facilities
Thermodynamic flow properties of gases in the boundary layer or the flowfield have been mainly deduced from pressures and temperatures measured on a model. However, further progress with respect to an understanding of these properties requires a more complete characterization of the layer including determination of the gas composition and chemistry. Most attempts to measure boundary layer chemistry involve the employment of a mass spectrometer and an associated gas sampling system. The three major limiting factors which must be addressed for species measurement in aerothermodynamic investigations on models at reentry stream velocities, are gas sampling effects, instrument limitations, and problems with data acquisition. The present investigation is concerned with a concentrated effort to quantitatively identify and correct for instrument and sampling system effects, and to develop a miniaturized high performance mass spectrometer for on-model real-time analysis of the boundary layer and its associated atmosphere.
Caleras in the solar system
Caldera-topped volcanoes are the largest volcanic edifices on a planet, and represent relatively long term development of near surface magma chambers. The types, geometries, numbers, and distributions of calderas on the Earth, Mars, Venus, and Io are compared.
Experience, problems, and subtleties of electrostatic discharge at JPL
Approaches used to control electrostatic discharge (ESD) at the JPL are discussed. ESD control problems generally occur in the following: (1) wrist straps; (2) outer garments that preclude the generation of static charge; and (3) materials, items, techniques, or processes permitting the development of a static charge. Consideration is given to the cleaning of antistatic materials, outside contracts, vapor degreasing, and electrostatically charged electrical cables.
Telescope simulators for Hubble - An overview of optical designs
This paper briefly describes optical design of the Hubble Space Telescope (HST) and overviews three optical design simulators for HST which have been proposed for use as verification tools to characterize the performance of second-generation instruments during ground testing. These simulators are: the Refractive Aberrated Simulator developed at Ball Aerospace, the Optical Simulator developed at Laboratoire Astronomie Spatiale, and the Jet Propulsion Laboratory Stimulus. Relative advantages and disadvantages of each optical configuration are discussed.
Combined 2-micron Dial and Doppler Lidar: Application to the Atmosphere of Earth or Mars
A concept is explored for combining the Doppler and DIAL techniques into a single, multifunctional instrument. Wind, CO2 concentration, and aerosol density can all be measured. Technology to build this instrument is described, including the demonstration of a prototype lidar. Applications are described for use in the Earth science. The atmosphere of Mars can also be studied, and results from a recently-developed simulation model of performance in the Martian atmosphere are presented.
The Origin of the EUV Late Phase: A Case Study of the C8.8 Flare on 2010 May 5
Since the launch of NASA's Solar Dynamics Observatory on 2010 February 11, the Extreme ultraviolet Variability Experiment (EVE) has observed numerous flares. One interesting feature observed by EVE is that a subset of flares exhibit an additional enhancement of the 2-3 million K emission several hours after the flares soft X-ray emission. From the Atmospheric Imaging Assembly (AIA) images, we observe that this secondary emission, dubbed the EUV late phase, occurs in the same active region as the flare but not in the same coronal loops. Here, we examine the C8.8 flare that occurred on 2010 May 5 as a case study of EUV late phase flares. In addition to presenting detailed observations from both AIA and EVE, we develop a physical model of this flare and test it using the Enthalpy Based Thermal Evolution of Loops (EBTEL) model.
Wrap-rib antenna concept development overview
The wrap rib antenna design of a parabolic reflector large space antenna is discussed. Cost estimates, design/mission compatibility, deployment sequence, ground based tests, and fabrication are discussed.
Fielding An Amphibious UAV: Development, Results, and Lessons Learned
This report summarizes the work completed on the design and flight-testing of a small, unmanned, amphibious demonstrator aircraft that flies autonomously. The aircraft named ACAT (Autonomous Cargo Amphibious Transport) is intended to be a large cargo carrying unmanned aircraft that operates from water to avoid airspace and airfield conflict issues between manned and unmanned aircraft. To demonstrate the feasibility of this concept, a demonstrator ACAT was designed, built, and flown that has a six-foot wingspan and can fly autonomously from land or water airfield. The demonstrator was designed for a 1-hour duration and 1-mile telemetry range. A sizing code was used to design the smallest demonstrator UAV to achieve these goals. The final design was a six-foot wingspan, twin hull configuration that distributes the cargo weight across the span, reducing the wing structural weight. The demonstrator airframe was constructed from balsa wood, fiberglass, and plywood. A 4-stroke model airplane engine powered by methanol fuel was mounted in a pylon above the wing and powers the ACAT UAV. Initial flight tests from land and water were conducted under manual radio control and confirmed the amphibious capability of the design. Flight avionics that were developed by MLB for production UAVs were installed in the ACAT demonstrator. The flight software was also enhanced to permit autonomous takeoff and landing from water. A complete autonomous flight from ahard runway was successfully completed on July 5, 2001 and consisted of a take-off, rectangular flight pattern, and landing under complete computer control. A completely autonomous flight that featured a water takeoff and landing was completed on October 4, 2001. This report describes these activities in detail and highlights the challenges encountered and solved during the development of the ACAT demonstrator. hard runway was successfully completed on July 5, 2001 and consisted of a take-off, rectangular flight pattern, and landing under complete computer control. A completely autonomous flight that featured a water takeoff and landing was completed on October 4, 2001. This report describes these activities in detail and highlights the challenges encountered and solved during the development of the ACAT demonstrator.
Computer program TRACK performs transient and/or steady state thermal analysis with coupled fluid flow and heat conduction
Computer program called TRACK was developed by combining a transient fluid flow computer code and the existing modified TOSS heat conduction code to perform the computation.
Investigation of the reaction of 5Al-2.5Sn titanium with hydrogen at subzero temperature
An investigation of the effect of temperature on the surface hydriding reaction of 5Al-2.5Sn titanium exposed to hydrogen at 250 psig was made. The temperature range studied extended from 160 F to -160 F. Reaction conditions were controlled so as to expose a vacuum-cleaned, oxide-free alloy surface to an ultrapure hydrogen atmosphere. Reaction times up to 1458 hours were studied. The hydriding reaction was extremely sensitive to experimental variables and the reproducibility of reaction behavior was poor. However, it was demonstrated that the reaction proceeded quite rapidly at 160 F; as much as 1 mil surface hydriding being observed after exposure for 162 hours. The amount of hydriding appeared to decrease with decreasing temperature at 75 F, -36 F, and -76 F. No surface hydriding was detected either by vacuum fusion analysis or by metallographic examination after exposure for 1458 hours at -110 F or -160 F. Tensile properties were unaffected by surface hydriding of the severity developed in this program (up to 1 mil thick) as determined by slow strain rate testing of hydrided sheet tensile samples.
An investigation for the development of an integrated optical data preprocessor
The successful fabrication and demonstration of an integrated optical circuit designed to perform a parallel processing operation by utilizing holographic subtraction to simultaneously compare N analog signal voltages with N predetermined reference voltages is summarized. The device alleviates transmission, storage and processing loads of satellite data systems by performing, at the sensor site, some preprocessing of data taken by remote sensors. Major accomplishments in the fabrication of integrated optics components include: (1) fabrication of the first LiNbO3 waveguide geodesic lens; (2) development of techniques for polishing TIR mirrors on LiNbO3 waveguides; (3) fabrication of high efficiency metal-over-photoresist gratings for waveguide beam splitters; (4) demonstration of high S/N holographic subtraction using waveguide holograms; and (5) development of alignment techniques for fabrication of integrated optics circuits. Important developments made in integrated optics are the discovery and suggested use of holographic self-subtraction in LiNbO3, development of a mathematical description of the operating modes of the preprocessor, and the development of theories for diffraction efficiency and beam quality of two dimensional beam defined gratings.
Two-color holography concept (T-CHI)
The Material Processing in the Space Program of NASA-MSFC was active in developing numerous optical techniques for the characterization of fluids in the vicinity of various materials during crystallization and/or solidification. Two-color holographic interferometry demonstrates that temperature and concentration separation in transparent (T-CHI) model systems is possible. The experiments were performed for particular (succinonitrile) systems. Several solutions are possible in Microgravity Sciences and Applications (MSA) experiments on future Shuttle missions. The theory of the T-CHI concept is evaluated. Although particular cases are used for explanations, the concepts developed will be universal. A breadboard system design is also presented for ultimate fabrication and testing of theoretical findings. New developments in holography involving optical fibers and diode lasers are also incorporated.
Software risk management through independent verification and validation
Software project managers need tools to estimate and track project goals in a continuous fashion before, during, and after development of a system. In addition, they need an ability to compare the current project status with past project profiles to validate management intuition, identify problems, and then direct appropriate resources to the sources of problems. This paper describes a measurement-based approach to calculating the risk inherent in meeting project goals that leverages past project metrics and existing estimation and tracking models. We introduce the IV&V Goal/Questions/Metrics model, explain its use in the software development life cycle, and describe our attempts to validate the model through the reverse engineering of existing projects.
Progress in Valve Modeling at Stennis Space Center
Efforts to develop the capability to model values used in testing rocket engine components are documented. Cryogenic liquid and gas valves models are presented.
Computational Simulations and the Scientific Method
As scientific simulation software becomes more complicated, the scientific-software implementor's need for component tests from new model developers becomes more crucial. The community's ability to follow the basic premise of the Scientific Method requires independently repeatable experiments, and model innovators are in the best position to create these test fixtures. Scientific software developers also need to quickly judge the value of the new model, i.e., its cost-to-benefit ratio in terms of gains provided by the new model and implementation risks such as cost, time, and quality. This paper asks two questions. The first is whether other scientific software developers would find published component tests useful, and the second is whether model innovators think publishing test fixtures is a feasible approach.