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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.

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At least 937 records · Page 52
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

A survey of mass analyzers

With the increasing applications of mass spectrometry technology to diverse services areas, a need has developed for a consolidated survey of the essential characteristics and features of the various instruments and techniques. This report is one approach to satisfying this need. Information has been collected and consolidated into a format which includes for each approach: (1) a general technique description, (2) instrument features information, and (3) a summary of pertinent advantages and disadvantages. With this information, the potential mass spectrometer user should be able to more efficiently select the most appropriate instrument.

Moore, W. W., Jr.↗
NASA NTRS1973

An initial step: A demonstration project

To initiate the transition into a clean and diverse energy environment independent of fossil-based fuels, the rapid development of a subsonic, hydrogen-fueled aircraft is recommended. Tables are presented on characteristics of synthetic fuels, comparisions with JP-4 and gasoline, comparison of nitric oxide emissions from hydrocarbon and hydrogen fuels vs. final flame temperature, and sensitivity limits of LH2 detectors.

Source record↗
NASA NTRS1973

Synthetic oils

Synthetic lubricants are discussed by chemical class and their general strengths and weaknesses in terms of lubrication properties are analyzed. Comparative ratings are given for 14 chemical classes and are used as a guide for lubricant selection. The effects of chemical structure on the properties of the lubricant are described with special emphasis on thermal stability. The diversity of synthetic lubricants which is provided by the wide range of properties permits many applications, some of which are reported.

Hatton, R. E.↗
NASA NTRS1973

Geomorphology subprogram: Geomorphological map of Occidental region of Bolivia, utilizing ERTS imagery

The author has identified the following significant results. Due to the receipt of ERTS-1 imagery, Bolivia will have for the first time a geomorphological map at a scale of 1:100,000. Now the researcher and the student will be able to compare the distribution of the existing shapes of the country, which have been modelled by diverse processes, factors, and agents. This geomorphological information will be very useful in its application to mining, especially alluvial beds, engineering work, and other geological studies. This map is divided into ten geomorphological units which coincide with the geostructural units of the western region of the country.

Brockmann, C. E.↗
NASA NTRS1973

Study of data collection platform concepts: Data collection system user requirements

The overall purpose of the survey was to provide real world data on user requirements. The intent was to assess data collection system user requirements by questioning actual potential users rather than speculating on requirements. The end results of the survey are baseline requirements models for both a data collection platform and a data collection system. These models were derived from the survey results. The real value of these models lies in the fact that they are based on actual user requirements as delineated in the survey questionnaires. Some users desire data collection platforms of small size and light weight. These sizes and weights are beyond the present state of the art. Also, the survey provided a wealth of information on the nature and constituency of the data collection user community as well as information on user applications for data collection systems. Finally, the data sheds light on the generalized platform concept. That is, the diversity of user requirements shown in the data indicates the difficulty that can be anticipated in attempting to implement such a concept.

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NASA NTRS1973

Responses to rotating linear acceleration vectors considered in relation to a model of the otolith organs

Human subjects were exposed to a linear acceleration vector that rotated in the transverse plane of the skull without angular counterrotation. Lateral eye movements showed a sinusoidal change in slow phase velocity and an asymmetry or bias in the same direction as vector rotation. A model is developed that attributes the oculomotor response to otolithic mechanisms. It is suggested that the bias component is the manifestation of torsion of the statoconial plaque relative to the base of the utricular macula and that the sinusoidal component represents the translational oscillation of the statoconia. The model subsumes a hypothetical neural mechanism which allows x- and y-axis accelerations to be resolved. Derivation of equations of motion for the statoconial plaque in torsion and translation, which take into account forces acting in shear and normal to the macula, yield estimates of bias and sinusoidal components that are in qualitative agreement with the diverse experimental findings.

Benson, A. J.↗
NASA NTRS1974

Millimeter wavelength propagation studies

The investigations conducted for the Millimeter Wavelength Propagation Studies during the period December, 1966, to June 1974 are reported. These efforts included the preparation for the ATS-5 Millimeter Wavelength Propagation Experiment and the subsequent data acquisition and data analysis. The emphasis of the OSU participation in this experiment was placed on the determination of reliability improvement resulting from the use of space diversity on a millimeter wavelength earth-space communication link. Related measurements included the determination of the correlation between radiometric temperature and attenuation along the earth-space propagation path. Along with this experimental effort a theoretical model was developed for the prediction of attenuation statistics on single and spatially separated earth space propagation paths. A High Resolution Radar/Radiometer System and Low Resolution Radar System were developed and implemented for the study of intense rain cells in preparation for the ATS-6 Millimeter Wavelength Propagation Experiment.

Hodge, D. B.↗
NASA NTRS1974

Geologic interpretation of ERTS-1 satellite images for West Aswan Area, Egypt

ERTS-1 images of West Aswan area were interpreted in terms of geology, drainage, and structure. Twenty-two geological units were distinguished on ERTS-1 images in West Aswan area covering geological formations and erosional levels within some formations ranging from the Precambrian to the Quaternary. Apart from the distinction of Aswan monumental granite the investigated area shows very interesting exposures of sedimentary rocks ranging from the Cretaceous to the Quaternary. Of special interest is the delineation of the iron-ore member of the Nubian Sandstone and the phosphate-bearing formation. The tracing of the geological formations from south to north and the distinction of the varied geological units within the Pliocene and Quaternary, and the discussion on the origin of tufa are of particular significance. Also, the tracing on these images of major fractures and faults intercepting Aswan Dam Reservoir and their significance on the seepage and possible future development of diversion channels from reservoir is emphasized.

Elshazly, E. M.↗
NASA NTRS1974

Evaluation of remote sensing and automatic data techniques for characterization of wetlands

This investigation has been conducted in the Atchafalaya River Basin of South Central Louisiana. This is a humid area of heavily forested swamps with a large volume of flow mostly from a diversion of the lower Mississippi River. Techniques to obtain enlarged imagery from computer compatible tapes of ERTS data without photographic enlargement is explained and illustrated. Techniques of extraction of environmental information from single bands and multiband pattern recognition procedures are explained and evaluated. A comparison of pattern recognition classifications of the Atchafalaya Basin by aircraft multispectral scanner and ERTS MSS data is made. Data for this comparison were gathered within three weeks of each other in the winter of 1973. Scorecards of the accuracy of the classifications are presented. Recommendations are made concerning the utilization of each sensor platform to perform specific tasks of wetlands characterization.

Cartmill, R. H.↗
NASA NTRS1974

ESIAC: A data products system for ERTS imagery (time-lapse viewing and measuring)

An Electronic Satellite Image Analysis Console (ESIAC) has been developed for visual analysis and objective measurement of earth resources imagery. The system is being employed to process imagery for use by USGS investigators in several different disciplines studying dynamic hydrologic conditions. The ESIAC provides facilities for storing registered image sequences in a magnetic video disc memory for subsequent recall, enhancement, and animated display in monochrome or color. The unique feature of the system is the capability to time-lapse the ERTS imagery and/or analytic displays of the imagery. Data products have included quantitative measurements of distances and areas, brightness profiles, and movie loops of selected themes. The applications of these data products are identified and include such diverse problem areas as measurement of snowfield extent, sediment plumes from estuary dicharge, playa inventory, phreatophyte and other vegetation changes. A comparative ranking of the electronic system in terms of accuracy, cost effectiveness and data output shows it to be a viable means of data analysis.

Evans, W. E.↗
NASA NTRS1974

Fabrication technology: A compilation

A compilation is presented which supplies technical information on the assembly of diverse components into functional assemblies and subassemblies, as well as information on several fasteners and fastening techniques that join components, subassemblies, and complete assemblies to achieve a functional unit. Quick-disconnect fasteners are described, along with several devices and methods for attaching thermal insulators, and for joining and separating objects in the absence of gravity.

Source record↗
NASA NTRS1974

Pioneer Mars surface penetrator mission. Mission analysis and orbiter design

The Mars Surface Penetrator mission was designed to provide a capability for multiple and diverse subsurface science measurements at a low cost. Equipment required to adapt the Pioneer Venus spacecraft for the Mars mission is described showing minor modifications to hardware. Analysis and design topics which are similar and/or identical to the Pioneer Venus program are briefly discussed.

Source record↗
NASA NTRS1973

ATS-F Comsat Millimeter Wave Propagation Experiment

The ATS-F Comsat Millimeter Wave Propagation Experiment has been designed to gather statistical data on the attenuation caused by rain at millimeter wave frequencies. These data will be used to determine system design parameters for future communications satellite systems operating at frequencies above 10 GHz. The experiment has 39 ground terminals transmitting at 13.2 or 17.8 GHz to a transponder on board the ATS-F satellite. The transponder retransmits these signals at 4 GHz to a central earth terminal which records their amplitudes once each second. The data will be analyzed to provide probabilities of attenuation as functions of parameters such as rainfall, location, and time. These probabilities can then be used to determine the required power margins of millimeter wave communications systems. Techniques of overcoming severe attenuation such as site diversity and the use of a spot beam to increase the power level at selected locations will also be evaluated.

Westerlund, L. H.↗
NASA NTRS1973

Field-determined oscillations in the magnetosheath as possible source of medium-period, daytime micropulsations

Studies of the magnetosheath show it to be characterized by the variable occurrence of large amplitude, sometimes quasiperiodic, field oscillations at diverse distances inward from the bow shock, including the region in proximity with the magnetopause. One established cause of such oscillations near the shock is local oblique orientation of the interplanetary field to the nominal shock surface, and there is evidence that the oscillations, or pulsations, composing the oblique structure appear also downstream in the sheath. It is suggested that medium-period micropulsations, exemplified by pc 3, might be excited in the magnetosphere when proper alignment of the interplanetary field allows shock pulsations to be convected to the magnetopause by plasma flow through the subsolar section of the magnetosheath.

Greenstadt, E. W.↗
NASA NTRS1974

Connective stability of nonlinear matrix systems

Consideration of stability under structural perturbations of free dynamic systems described by the differential equation dx/dt = A(t,x)x, where the matrix A(t,x) has time-varying nonlinear elements. The concept of 'connective stability' is introduced to study the structural properties of competitive-cooperative nonlinear matrix systems. It is shown that stability reliability in such systems is high and that they remain stable despite time-varying (including 'on-off') interaction among individual agents present in the system. The results obtained can be used to study stability aspects of mathematical models arising in as diverse fields as economics, biology, arms races, and transistor circuits.

Siljak, D. D.↗
NASA NTRS1973

Condensed phase details in the time-independent combustion of AP/composite propellants

The problem of nonmetallized ammonium perchlorate (AP)/composite propellant combustion is studied with the aim of coherently interpreting apparently diverse experimental data. Three fundamental hypotheses are introduced: the extent of propellant degradation at the vaporization step has to be specified through a scientific criterion; condensed phase degradation of AP to vaporizable fragments is the overall rate-limiting reaction; the rate of combustion in the gas phase is controlled by diffusive-mixing processes. Theoretical predictions of the regression rates of AP are seen to match well with experimental observations. Theoretical curves of regression rate are presented for a typical composite propellant. It is seen through analyses that either of the two familiar models for the gas phase (flame sheet approximation and uniform combustion) describes the general behavior adequately, hence de-emphasizing the role of gas phase details in propellant combustion.

Kumar, R. N.↗
NASA NTRS1975

Page composer to translate binary electrical data to optical form

Composer converts binary data to optical form for storage as hologram. Device consists of an array of deformable metal membranes controlled by MOSFET's. Device is fast, produces high contrast ratios, does not degrade with extended use, and can be addressed from diverse angles.

Bailey, G. A.↗
NASA NTRS1974

Ecological effects and environmental fate of solid rocket exhaust

Specific target processes were classified as to the chemical, chemical-physical, and biological reactions and toxic effects of solid rocket emissions within selected ecosystems at Kennedy Space Center. Exposure of Citris seedlings, English peas, and bush beans to SRM exhaust under laboratory conditions demonstrated reduced growth rates, but at very high concentrations. Field studies of natural plant populations in three diverse ecosystems failed to reveal any structural damage at the concentration levels tested. Background information on elemental composition of selected woody plants from two terrestrial ecosystems is reported. LD sub 50 for a native mouse (peromysous gossypinus) exposed to SRM exhaust was determined to be 50 ppm/g body weight. Results strongly indicate that other components of the SRM exhaust act synergically to enhance the toxic effects of HCl gas when inhaled. A brief summary is given regarding the work on SRM exhaust and its possible impact on hatchability of incubating bird eggs.

Nimmo, B.↗