New developments in aluminum welding.
Aluminum welding, examining internal defects such as porosity and metallurgical changes in heat effected zone
METAL-METAL BONDING↗
SEARCH · Engineering Papers
Results for “effective changes”
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.
Estimated surface motions of the earth's core.
Frozen field estimation of surface flow of earth core and effects of secular change resulting from flow pattern nonuniformity
SECULAR PERTURBATION↗
Flight investigation to determine the effect of longitudinal characteristics on low-speed instrument operation
Variable-stability helicopter flight tests under instrument flight rules to determine effects of gross changes in longitudinal static stability for V/STOL handling qualities
Di Carlo, D. J.↗
Muscle training and blood flow
Isometric and isotonic exercises conducted to determine effects on muscle changes and blood flow
Carlson, L. D.↗
Contourograph display system for monitoring electrocardiograms
Electrocardiogram is displayed as a contourogram on the cathode ray tube of a variable-persistence oscilloscope. Each cycle is stacked below its predecessors giving a three dimensional effect. A major change in the signal is apparent as a change in the contourogram pattern.
Golden, D. P., Jr.↗
Design of two-dimensional sharp-edged-throat supersonic nozzle with boundary-layer correction
Computer program accounts for effective nozzle geometry changes due to boundary layer displacement thickness. Program input and output are discussed.
Goldman, L. J.↗
Universal inverted flexure
Flexure block fabricated from single piece of material minimizes effect of temperature changes and prevents overstressing of the flexing element.
Hadland, W. O.↗
Three-meter telescope study
A means is presented whereby the effect of various changes in the most important parameters of a three meter aperature space astronomy telescope can be evaluated to determine design trends and to optimize the optical design configuration. Methods are defined for evaluating the theoretical optical performance of axisymmetric, centrally obscured telescopes based upon the intended astronomy research usage. A series of design parameter variations is presented to determine the optimum telescope configuration. The design optimum requires very fast primary mirrors, so the study also examines the current state of the art in fabricating large, fast primary mirrors. The conclusion is that a 3-meter primary mirror having a focal ratio as low as f/2 is feasible using currently established techniques.
Wissinger, A.↗
Instabilities in uranium plasma and the gas-core nuclear rocket engine
The nonlinear evolution of unstable sound waves in a uranium plasma has been calculated using a multiple time-scale asymptotic expansion scheme. The fluid equations used include the fission power density, radiation diffusion, and the effects of the changing degree of ionization of the uranium atoms. The nonlinear growth of unstable waves is shown to be limited by mode coupling to shorter wavelength waves which are damped by radiation diffusion. This mechanism limits the wave pressure fluctuations to values of order delta P/P approximates 0.00001 in the plasma of a typical gas-core nuclear rocket engine. The instability is thus not expected to present a control problem for this engine.
Tidman, D. A.↗
Advanced study of video signal processing in low signal to noise environments
A generalized mathematical and computer model of the revised Apollo television system was developed and used to determine spectral compatibility with the overall Apollo communication system. In particular the effects of the change to commercial television format from slow-scan black and white on the principal telemetering subcarriers was analyzed. Experimental data was obtained from MSC telemetry division confirming the analytical results.
Garden, F.↗
Study of Spray Disintegration in Accelerating Flow Fields
An analytical and experimental investigation was conducted to perform "proof of principlem experiments to establish the effects of propellant combustion gas velocity on propella'nt atomization characteristics. The propellants were gaseous oxygen (GOX) and Shell Wax 270. The fuel was thus the same fluid used in earlier primary cold-flow atomization studies using the frozen wax method. Experiments were conducted over a range in L* (30 to 160 inches) at two contraction ratios (2 and 6). Characteristic exhaust velocity (c*) efficiencies varied from SO to 90 percent. The hot fire experimental performance characteristics at a contraction ratio of 6.0 in conjunction with analytical predictions from the drovlet heat-up version of the Distributed Energy Release (DER) combustion computer proDam showed that the apparent initial dropsize compared well with cold-flow predictions (if adjusted for the gas velocity effects). The results also compared very well with the trend in perfomnce as predicted with the model. significant propellant wall impingement at the contraction ratio of 2.0 precluded complete evaluation of the effect of gross changes in combustion gas velocity on spray dropsize.
Nurick, W. H.↗
Instabilities in uranium plasma.
The nonlinear evolution of unstable sound waves in a uranium plasma has been calculated using a multiple time-scale asymptotic expansion scheme. The fluid equations used include the fission power density, radiation diffusion, and the effects of the changing degree of ionization of the uranium atoms. The nonlinear growth of unstable waves is shown to be limited by mode coupling to shorter wavelength waves which are damped by radiation diffusion. This mechanism limits the wave pressure fluctuations to values of order delta P/P equal to about .00001 in the plasma of a typical gas-core nuclear rocket engine. The instability is thus not expected to present a control problem for this engine.
Tidman, D. A.↗
Model atmospheres for cool supergiant stars.
The results of an exploratory grid of model atmospheres for cool giant stars are used to illustrate the effect of varying the chemical composition of the atmosphere. The effects of composition changes (depletion of C and O, enrichment of N, and increase in the ratio C/O), which might be expected from processing of the original material of a star through the CNO cycle of nuclear burning, are studied. The models also include the important CN opacity. They are illustrated by giving several representative T-P and T-tau diagrams, spectral energy curves, and column density tables of molecules.
Alexander, D. R.↗
Combined sun-acquisition and sun gate-sensor system for spacecraft attitude control
Arrangement combines acquisition and gate functions and reduces sensitivity so that attitude control is effective regardless of changes in solar intensity. There are five photoconductive detectors all electrically interconnected. Detectors are so positioned that, regardless of spacecraft orientation at any instant of interest, at least one detector is illuminated.
Schmidt, L. F.↗
Aerospace vehicle synthesis program
A modified version of the Aerospace Vehicle Synthesis Program (VSP) to simulate a space shuttle on the computer is presented. The effects of various changes such as payload weight, and orbital velocity can be determined along with minimum costs in vehicle design. The program logic, and weight estimating equations are discussed, and an example case of a solid propellant boosted, drop tank orbiter is included to indicate the type of results produced by the VSP.
Source record↗
Development and fabrication of a graphite polyimide box beam
The state-of-the-art of graphite/polyimide structures was evaluated and key design and fabrication issues to be considered in future hardware programs are defined. The fabrication and testing at 500 F of a graphite/polyimide center wing box beam using OV-10A aircraft criteria was accomplished. The baseline design of this box was developed in a series of studies of other advanced composite materials: glass/epoxy, boron/epoxy, and boron/polyimide. The use of this basic design permits ready comparison of the performance of graphite/polyimide with these materials. Modifications to the baseline composite design were made only in those areas effected by the change of materials. Processing studies of graphite fiber polyimide resins systems resulted in the selection of a Modmor II/Gemon L material.
Nadler, M. A.↗
Investigation of Atmospheric Effects in Image Transfer
Several computations on radiation emerging from the atmosphere for different aerosol models have been performed and the reflection matrix of a given surface was defined by incident light signature analyses. A two channel polarimeter is being constructed for measuring the Stokes parameters of reflected light. Surface albedo measurements were made in six wavelength ranges in the ultraviolet, visible, and near infrared spectral regions for six different vegetated surfaces, four soil surfaces, and two roadway surfaces. The effects of polarization changes on the intensity of projected images were studied by using a rotatable polarizer in front of an aerial camera lens.
Coulson, K. L.↗
Glaciation of northwestern Wyoming interpreted from ERTS-1
Analysis of ERTS Imagery has shown a number of alpine glacial features can be recognized and mapped successfully. Although the Wyoming mountains are generally regarded as the type locality for Rocky Mountain glaciation some areas have not been studied from a glacial standpoint because of inaccessibility or lack of topographic control. ERTS imagery provides an excellent base for this type of regional geomorphic study. A map of maximum extent of Wisconsin Ice, flow directions and major glacial features was compiled from interpretation of the ERTS imagery. Features which can be mapped are large moraines, outwash fans and terraces. Present-day glaciers and snowfields are easily discriminated and mapped. Glaciers and glacial deposits which serve as aquifers play a significant role in the hydrologic cycle and are important because of the increasing demand placed on our water resources. ERTS provides a quick and effective method for change detection and inventory of these vital resources.
Breckenridge, R. M.↗