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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 847 records · Page 47
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Manipulation of particles by weak forces

Quantitative relations between various force fields and their effects on the motion of particles of various sizes and physical characteristics were studied. The forces considered were those derived from light, heat, microwaves, electric interactions, magnetic interactions, particulate interactions, and sound. A physical understanding is given of the forces considered as well as formulae which express how the size of the force depends on the physical and electrical properties of the particle. The drift velocity in a viscous fluid is evaluated as a function of initial acceleration and the effects of thermal random motion are considered. A means of selectively sorting or moving particles by choosing a force system and/or environment such that the particle of interest reacts uniquely was developed. The forces considered and a demonstration of how the initial acceleration, drift velocity, and ultimate particle density distribution is affected by particle, input, and environmental parameters are tabulated.

Adler, M. S.↗
NASA NTRS1974

Skylab-3 handheld photography alphabetized geographical features list

The data was thoroughly researched using the Times Index-Gazetteer of the World, the Times Atlas of the World, and the National Atlas of the United States of America to ensure correct spelling and location of named features. The spelling and major geographical features applied to smaller features (minor) such as cities, towns, mountain peaks, etc., are in accordance with these publications. It is understood that some political boundaries and names of countries are subject to change. The data was written on NASA keypunch transmittal sheets and punched into data cards. These data cards were then machine sorted alphabetically by major feature and minor feature.

Mcniel, J. L.↗
NASA NTRS1974

Evidence about hydrate and solid water in the Martian surface from the 1969 Mariner infrared spectrometer

Results of laboratory simulation studies and comparative computer analyses of infrared spectral data regarding the presence, distribution, and form of condensed-phase water in the Martian surface. The data were obtained with the aid of the Mariner 6 and 7 spacecraft which were equipped with infrared spectrometers recording the infrared spectrum from 1.9 to 14.4 microns. From the analysis of these data evidence is obtained which signifies some sort of compositional and/or particle size variability of the extent and nature of hydration. Changes are noted which could be due to ice thinly covering a small fraction of the planetary surface in particularly cold spots, possibly on partially shaded slopes. At southerly latitudes, the fraction so covered seems to increase as the polar cap edge is approached. It is therefore concluded that there is strong evidence of ice formation on the planetary surface at the edge of the polar cap.

Pimentel, G. C.↗
NASA NTRS1974

The circumferentially notched cylindrical bar as a fracture toughness test specimen

The present work reviews the use of the notched cylinder as a screening specimen for use in sorting materials with respect to their relative levels of plane strain fracture toughness. Irwin's work in developing an estimate of stress intensity factors for the circumferentially cracked cylinder is reviewed. Some discrepancies between stress intensity factors determined with fatigue cracked notched cylinders and those determined with plate specimens are discussed. Problems in the technical realization of fatigue cracking a specimen are briefly discussed, and the problem of ensuring low eccentricity of loading when testing notch cylindrical specimens is considered. Finally, specimen size requirements for testing are examined.

Brown, W. F., Jr.↗
NASA NTRS1975

A system for multichannel recording and automatic reading of information

A system for the recording and processing of telescope data is considered for measurements of EW asymmetry. The information is recorded by 45 channels on a continuously moving 35-mm film. The dead time of the recorder is about 0.1 sec. A sorting electronic circuit is used to reduce the errors when the statistical time distribution of the pulses is recorded. The recorded information is read out by means of photoresistors. The phototransmitter signals are fed either to the mechanical recorder unit for preliminary processing, or to a logical circuit which controls the operation of the punching device. The punched tape is processed by an electronic computer.

Bogomolov, E. A.↗
NASA NTRS1975

Production of gaseous fuel by pyrolysis of municipal solid waste

Pilot plant tests were conducted on a simulated solid waste which was a mixture of shredded newspaper, wood waste, polyethylene plastics, crushed glass, steel turnings, and water. Tests were conducted at 1400 F in a lead-bath pyrolyser. Cold feed was deaerated by compression and was dropped onto a moving hearth of molten lead before being transported to a sealed storage container. About 80 percent of the feed's organic content was converted to gaseous products which contain over 90 percent of the potential waste energy; 12 percent was converted to water; and 8 percent remained as partially pyrolyzed char and tars. Nearly half of the carbon in the feed is converted to benzene, toluene and medium-quality fuel gas, a potential credit of over $25 per ton of solid waste. The system was shown to require minimal preprocessing and less sorting then other methods.

Crane, T. H.↗
NASA NTRS1975

A study to analyze six band multispectral images and fabricate a Fourier transform detector

An automatic Fourier transform diffraction pattern sampling system, used to investigate techniques for forestry classification of six band multispectral aerial photography is presented. Photographs and diagrams of the design, development and fabrication of a hybrid optical-digital Fourier transform detector are shown. The detector was designed around a concentric ring fiber optic array. This array was formed from many optical fibers which were sorted into concentric rings about a single fiber. All the fibers in each ring were collected into a bundle and terminated into a single photodetector. An optical/digital interface unit consisting of a high level multiplexer, and an analog-to-digital amplifier was also constructed and is described.

Shackelford, R. G.↗
NASA NTRS1975

Low altitude temperature and humidity profile data for application to aircraft noise propagation

A data search of the weather statistics from 11 widely dispersed geographical locations within the continental United States was conducted. The sites, located long both sea-coasts and in the interior, span the northern, southern, and middle latitudes. The weather statistics, retrieved from the records of these 11 sites, consist of two daily observations taken over a 10-year period. The data were sorted with respect to precipitation and surface winds and classified into temperature intervals of 5 C and relative humidity intervals of 10 percent for the lower 1400 meters of the atmosphere. These data were assembled in a statistical format and further classified into altitude increments of 200 meters. The data are presented as sets of tables for each site by season of the year and include both daily observations.

Connor, A. B.↗
NASA NTRS1974

Human physiological problems in zero gravity - An attempt at understanding through systems analysis

When the experimental situation is that of man exposed to a gravitationless environment for varying periods of time, the possible importance and value of a related modeling effort is readily apparent. One of the main objectives of the Skylab Program, with its missions of 28, 59, and 85 day duration concerned biomedical investigations of various types, and large amounts of relevant experimental data have been gathered and are in the process of being sorted and interpreted. In order to be of eventual usefulness in forming and testing consistent physiological hypotheses concerning the effect of zero gravity on man, a modeling effort was established in 1972 through the General Electric Company, Space Division, Houston, Texas. An account is given of some of the developments completed or in progress as part of this modeling effort. A long-term cardiovascular model and a large model of the systemic circulation are discussed.

White, R. J.↗
NASA NTRS1975

On the effect of timing errors in run length codes

Many redundancy removal algorithms employ some sort of run length code. Blocks of timing words are coded with synchronization words inserted between blocks. The probability of incorrectly reconstructing a sample because of a channel error in the timing data is a monotonically nondecreasing function of time since the last synchronization word. In this paper we compute the 'probability that the accumulated magnitude of timing errors equal zero' as a function of time since the last synchronization word for a zero-order predictor (ZOP). The result is valid for any data source that can be modeled by a first-order Markov chain and any digital channel that can be modeled by a channel transition matrix. An example is presented.

Wilkins, L. C.↗
NASA NTRS1975

Petrology of lunar soils

The paper summarizes the physical and petrographic characteristics of the finer-grained fractions (less than 1 cm) of lunar regolith soil in Apollo and Luna samples. Lunar soils are poorly sorted and consist mostly of lithic and mineral debris derived by impact comminution of the underlying bedrock and glass particles formed by impact melting. Agglutinates constitute an important soil component and are key factors in the genetic history of lunar soil. Some models concerning the development of lunar regolith based on soil studies are examined.

Heiken, G.↗
NASA NTRS1975

Stratification in the lunar regolith - A preliminary view

Although our knowledge of lunar regolith stratification is incomplete, several categories of thick and thin strata have been identified. Relatively thick units average 2 to 3 cm in thickness, and appear surficially to be massive. On more detailed examination, these units can be uniformly fine-grained, can show internal trends, or can show internal variations which apparently are random. Other thick units contain soil clasts apparently reworked from underlying units. Thin laminae average approximately 1 mm in thickness; lenticular distribution and composition of some thin laminae indicates that they are fillets shed from adjacent rock fragments. Other dark fine-grained well-sorted thin laminae appear to be surficial zones reworked by micrometeorites. Interpretations of stratigraphic succession can be strengthened by the occurrence of characteristic coarse rock fragments and the orientation of large spatter agglutinates, which are commonly found in their original depositional orientation.

Duke, M. B.↗
NASA NTRS1975

Evidence for magnetic field line reconnection in the solar wind

The basic scheme of Petschek's (1963) models for slow and fast magnetic reconnection in the solar wind is reviewed in order to determine what sort of results one would expect from satellite observations of possible reconnection processes. Data from HEOS 1 and OGO 5 are then analyzed, in which four observations of neutral sheet structures with large change of magnetic field direction were made. All four may be interpreted as indicating magnetic line reconnections rather than as D-sheets because they all show two distinct discontinuities which bound a lower magnetic field intensity region. The geometry of the magnetic field in the reconnection region appears to be similar to that described by Petschek. In one case the reconnection rate is in agreement with Petschek's prediction, but in the other three cases it is much larger than his limit. The reconnection rates observed do, however, agree with Sonnerup's (1972) limit.

Formisano, V.↗
NASA NTRS1977

Data-management and information system

User command language consists of unabbreviated English words. System allows user to create, delete, sort, merge, update, punch, or transfer all or portion of any file in system without programmer assistance.

Long, J. J.↗
NASA NTRS1977

Information retrieval and display system

Versatile command-driven data management system offers users, through simplified command language, a means of storing and searching data files, sorting data files into specified orders, performing simple or complex computations, effecting file updates, and printing or displaying output data. Commands are simple to use and flexible enough to meet most data management requirements.

Groover, J. L.↗
NASA NTRS1975

MIRADS-2 Implementation Manual

The Marshall Information Retrieval and Display System (MIRADS) which is a data base management system designed to provide the user with a set of generalized file capabilities is presented. The system provides a wide variety of ways to process the contents of the data base and includes capabilities to search, sort, compute, update, and display the data. The process of creating, defining, and loading a data base is generally called the loading process. The steps in the loading process which includes (1) structuring, (2) creating, (3) defining, (4) and implementing the data base for use by MIRADS are defined. The execution of several computer programs is required to successfully complete all steps of the loading process. This library must be established as a cataloged mass storage file as the first step in MIRADS implementation. The procedure for establishing the MIRADS Library is given. The system is currently operational for the UNIVAC 1108 computer system utilizing the Executive Operating System. All procedures relate to the use of MIRADS on the U-1108 computer.

Source record↗
NASA NTRS1977

Effects of pressure waves

Two parameters, side on overpressure and side on impulse loads, and their application to the determination of structural damage to buildings and vehicles in the vicinity of an explosion are investigated. Special consideration was given to what constitutes damage and what level of damage is acceptable. Solutions were sorted through the examination of glass breakage, curve fit to bomb damage, overturning of marginal structures (buses, trucks, mobile homes) subject to toppling, and initiation of yielding in either beam or plate structural components. Three different empirical pressure versus impulse diagrams were presented - the first is for minor structural damage involving wrenched joints and partitions, the second is for major damage structural damage with load bearing members at least partially destroyed, and the third is for 50% to 75% of the building demolished. General guidelines were obtained from the results when the accurate structural details are unknown.

Source record↗
NASA NTRS1976

Particulate and aerosol detector

A device is described for counting aerosols and sorting them according to either size, mass or energy. The component parts are an accelerator, a capacitor sensor and a readout. The accelerator is a means for accelerating the aerosols toward the face of the capacitor sensor with such force that they partially penetrate the capacitor sensor, momentarily discharging it. The readout device is a means for counting the number of discharges of the capacitor sensor and measuring the amplitudes of these different discharges. The aerosols are accelerated by the accelerator in the direction of the metal layer with such force that they penetrate the metal and damage the oxide layers, thereby allowing the electrical charge on the capacitor to discharge through the damaged region. Each incident aerosol initiates a discharge path through the capacitor in such a fashion as to vaporize the conducting path. Once the discharge action is complete, the low resistance path no longer exists between the two capacitor plates and the capacitor is again able to accept a charge. The active area of the capacitor is reduced in size by the damaged area each time a discharge occurs.

Wortman, J. J.↗