A simple proof of a well-known oscillation theorem
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Coles, W. J.↗
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Results for “wells”
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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On the sharpness of cracks compared with Wells's COD
Crack opening displacement concept in fracture mechanics, considering crack tip radius as measure of extension potential
Roberts, E., Jr.↗
How well do we know 'cosmic' abundances
Cl chondrites approximating primordial solar system matter condensable fractions based on isotopic/elemental abundance continuity, fractionation patterns and chondrules absence
Anders, E.↗
FORTRAN 4 programs for the extraction of potential well parameters from the energy dependence of total elastic scattering cross sections
An attempt has been made to keep the programs as subroutine oriented as possible. Usually only the main programs are directly concerned with the problem of total cross sections. In particular the subroutines POLFIT, BILINR, GASS59/MAXLIK, SYMOR, MATIN, STUDNT, DNTERP, DIFTAB, FORDIF, EPSALG, REGFAL and ADSIMP are completely general, and are concerned only with the problems of numerical analysis and statistics. Each subroutine is independently documented.
Labudde, R. A.↗
Experimental approaches to well controlled studies of thin-film nucleation and growth.
Particular features and the performance of two experimental systems are described for quantitative studies of thin-film nucleation and growth processes including epitaxial depositions. System I consists of a modified LEED-Auger instrument combined with high-resolution electron microscopy. System II is a UHV electron microscope adapted for in-situ deposition studies. The two systems complement each other ideally, and the combined use of both can result in a comprehensive investigation of vapor deposition processes not obtainable with any other known method.
Poppa, H.↗
On the analysis of glory scattering data for the extraction of information on the interatomic potential well.
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Bernstein, R. B.↗
Lunar evolution - How well do we know it now.
The currently known astronomical, chemical, and magnetic data are not uniquely indicative of an extensively and globally molten moon. It is argued that an accretional layering occurred in the moon, but at temperatures below solidus. The excess mass in the near side of the moon compatible with a 2-km displacement in the center of mass relative to the center of figure and the moment of inertia data is considered to be due to Fe-FeS liquid formation and inhomogeneous segregation. These Fe-FeS bodies, termed 'fescons,' are shown to be capable of accounting for the presently available magnetization data, by acting as small regenerative dynamos with a time-stability less than that of the terrestrial equivalent. The chemical characteristics of the highly differentiated materials, are considered to be due to small-scale localized melting caused by collisional events, from sources in which accessory phases play a significant role. Mare basalts are considered to be melts in the overlying material produced at a later time by K-40 radioactivity in the fescons. Some consequences of the present hypothesis are suggested. It is concluded that these and other characteristics of the lunar materials are reconcilable with a 'cold' moon, such as discussed by Urey over the past two decades.
Murthy, V. R.↗
Two well-corrected four-mirror telescopes
A study has been conducted of a configuration resembling that of a Cassegrain telescope with two nested mirrors in the plane of the primary and two nested mirrors in the plane of the secondary. The focal plane was located in the plane of the first and the third mirror. The four surfaces available in the device for corrections made it possible to correct for third-order spherical aberration, coma, astigmatism, and distortion.
Korsch, D.↗
Pulse-echo probe of rock permeability near oil wells
Processing method involves sequential insonifications of borehole wall at number of different frequencies. Return signals are normalized in amplitude, and root-mean-square (rms) value of each signal is determined. Values can be processed to yield information on size and number density of microfractures at various depths in rock matrix by using averaging methods developed for pulse-echo technique.
Narasimhan, K. Y.↗
A well posed boundary value problem in transonic gas dynamics
A boundary value problem for the Tricomi equation was studied in connection with transonic gas dynamics. The transformed equation delta u plus 1/3Y u sub Y equals 0 in canonical coordinates was considered in the complex domain of two independent complex variables. A boundary value problem was then set by prescribing the real part of the solution on the boundary of the real unit circle. The Dirichlet problem in the upper unit semicircle with vanishing values of the solution at Y = 0 was solved explicitly in terms of the hypergeometric function for the more general Euler-Poisson-Darboux equation. An explicit representation of the solution was also given for a mixed Dirichlet and Neumann problem for the same equation and domain.
Sanz, J. M.↗
Photoarchaeology. Reconnaissance tests using color, as well as other films, indicate that exploration studies may be reduced from months to hours
Various types of films were used to detect pre-Columbian archaeological sites in South Dakota. Natural color and color IR films (scale 1/10,000) provided the best interpretation medium.
Strandberg, C. H.↗
Process for producing a well-adhered durable optical coating on an optical plastic substrate
A low temperature plasma polymerization process is described for applying an optical plastic substrate, such as a polymethyl methacrylate lens, with a single layer abrasive resistant coating to improve the durability of the plastic.
Kubacki, R. M.↗
The attributes of a well-trained remote sensing technologist
Central concepts important to the training of the remote sensing technologist are presented. What employers appear to be looking for at this time in a prospective employee is discussed along with some ways in which faculty can get students interested in remote sensing. The attributes of a prime candidate and his goals are described. The current status of remote sensing education in colleges and universities is presented.
Estes, J. E.↗
Evaluation of aircraft microwave data for locating zones for well stimulation and enhanced gas recovery
Imaging radar was evaluated as an adjunct to conventional petroleum exploration techniques, especially linear mapping. Linear features were mapped from several remote sensor data sources including stereo photography, enhanced LANDSAT imagery, SLAR radar imagery, enhanced SAR radar imagery, and SAR radar/LANDSAT combinations. Linear feature maps were compared with surface joint data, subsurface and geophysical data, and gas production in the Arkansas part of the Arkoma basin. The best LANDSAT enhanced product for linear detection was found to be a winter scene, band 7, uniform distribution stretch. Of the individual SAR data products, the VH (cross polarized) SAR radar mosaic provides for detection of most linears; however, none of the SAR enhancements is significantly better than the others. Radar/LANDSAT merges may provide better linear detection than a single sensor mapping mode, but because of operator variability, the results are inconclusive. Radar/LANDSAT combinations appear promising as an optimum linear mapping technique, if the advantages and disadvantages of each remote sensor are considered.
Macdonald, H.↗
A bound for the smoothing parameter in certain well-known nonparametric density estimators
Two classes of nonparametric density estimators, the histogram and the kernel estimator, both require a choice of smoothing parameter, or 'window width'. The optimum choice of this parameter is in general very difficult. An upper bound to the choices that depends only on the standard deviation of the distribution is described.
Terrell, G. R.↗
Comparative study of choleretic agents in anesthetized rats as well as in restrained and and unrestrained rats, with or without compensation for biliary loss
Tests were conducted on Wistar rats by using 3 control choleretic agents: 1-phenyl-1-hydroxy n-pentane, dehydrocholic acid, and phenyl-dimethylacetic acid. The effects of these agents were compared in different experimental conditions. The comparative study of choleretic agents in anesthetized rats, in restrained and unrestrained rats, with or without compensation for biliary loss by the biliary secretion of restrained or unrestrained rats does not show, in systematic pharmecodynamic investigations, an obvious superiority over the methods based on the simple technique.
Labrid, C.↗
Expected cycle life versus depth of discharge relationships of well behaved single cells and cell strings
The factors that might influence the cycle life vs. depth of discharge relationship are examined. This is done first at the single cell level using a progressively more complex cell life model. This is then extended to multicell battery strings where the stochastic aspects associated with groupings of cells are introduced. These relationships are important when considering the weight, cost, and life of battery packs. The results of this theoretical study are compared with a recent review of actual cell cycling data. The factors examined are the rate of capacity loss, the amount of excess capacity built into the cells, and the penalty in capacity loss resulting from the use of deep depths of discharge. This study suggests that the relationship between cycle life and depth of discharge is not one that can be varied of significantly improved by cell research. The relationship appears to be determined by certain more or less fixed cell parameters. Among multicell strings, the standard deviation, as expected, plays an important role in determining overall battery life.
Thaller, L. H.↗
Chromospheric evaporation in a well-observed compact flare
Hudson and Ohki (1972) pointed out that the increase of the soft X-ray emission measure during flares might be accounted for in two different ways, either by 'coronal condensation', or by what they termed 'chromospheric rarefaction', now more commonly called 'chromospheric evaporation'. They ruled out coronal condensation on the basis of cornal mass content arguments. Moore et al. (1980) found it highly probable that the bulk of the mass of the soft X-ray emitting plasma is supplied during the rise phase by chromospheric evaporation from the feet of the soft X-ray loops. On the other hand, Cheng et al. (1981) argued that chromospheric evaporation is not important as a source of soft X-ray plasma. The present investigation is concerned with an event in which direct chromospheric observations contradict the conclusions reached by Cheng et al. Up to now chromospheric evaporation has always been an inference, without compelling positive evidence. In the current investigation, observations are considered which constitute such evidence.
Acton, L. W.↗