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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 289 records · Page 16
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

Energy distributions of radio galaxies

Far-infrared observations of 140 radio galaxies which span a range of over four orders of magnitude in radio power, (from weak nuclear sources in nearby galaxies, to powerful FR II doubled lobed sources at moderate redshift) are presented. The strength of the far-infrared emission is more closely correlated with core than total radio emission. Far-infrared emission in radio galaxies represents star formation that is more closely tied to the active nucleus than to the global properties of the galaxy. The far-infrared luminosity function shows good continuity between radio galaxies and radio loud quasars.

Impey, Chris↗
NASA NTRS1995

Adhesion, friction, and wear behavior of clean metal-ceramic couples

When a clean metal is brought into contact with a clean, harder ceramic in ultrahigh vacuum, strong bonds form between the two materials. The interfacial bond strength between the metal and ceramic surfaces in sliding contact is generally greater than the cohesive bond strength in the metal. Thus, fracture of the cohesive bonds in the metal results when shearing occurs. These strong interfacial bonds and the shearing fracture in the metal are the main causes of the observed wear behavior and the transfer of the metal to the ceramic. In the literature, the surface energy (bond energy) per unit area of the metal is shown to be related to the degree of interfacial bond strength per unit area. Because the two materials of a metal-ceramic couple have markedly different ductilities, contact can cause considerable plastic deformation of the softer metal. It is the ductility of the metal, then, that determines the real area of contact. In general, the less ductile the metal, the smaller the real area of contact. The coefficient of friction for clean surfaces of metal-ceramic couples correlates with the metals total surface energy in the real area of contact gamma A (which is the product of the surface energy per unit area of the metal gamma and the real area of contact (A)). The coefficient of friction increases as gamma A increases. Furthermore, gamma A is associated with the wear and transfer of the metal at the metal-ceramic interface: the higher the value of gamma A, the greater the wear and transfer of the metal.

Miyoshi, Kazuhisa↗
NASA NTRS1994

Solid carbon monoxide in the Serpens dark cloud

The 4.67 micrometer absorption feature of solid CO is an important signature of grain mantles in molecular clouds. This paper presents new observations of solid CO absorption in the spectra of four infrared sources in and behind the Serpens dark cloud. We also present supplementary 2.0-2.5 micrometer spectra which clarify the nature of selected sources. Solid CO profiles are compared with models based on laboratory data. In common with previous studies of other clouds, we find that the observed profiles are consistent with the presence of two distinct phases of CO-bearing ice, one dominated either by CO itself or by CO mixed with absorption relative to that of the water-ice feature at 3.1 micrometers is unusually high in Serpens: we deduce column densities for CO and H2O in solid form and conclude that the mean CO abundance in dust is 40% of the H2O abundance, compared with values in the range 0%-30% typical of other molecular clouds. On the basis of its 2.0-2.5 micrometer spectrum and near-infrared colors, we deduce the infrared source CK 2 to be a K5-M0 III field star situated behind the Serpens cloud and suffering 40-50 mag of visual extinction. Assuming empirical correlations between extinction and total (gas + dust) CO column density, we estimate the CO depletion (i.e., the fraction of interstellar CO in the line of sight tied up in grains) to be approximately 40% in the intracloud medium of the Serpens cloud, comparable with previous estimates for the Taurus dark cloud, and much higher than that found in the environments of protostellar objects.

Chiar, J. E.↗
NASA NTRS1998

Studies of Long Period Variability in Neutron Star HMXB Systems

The purpose of this effort was to investigate the long term, quasi-periodic variability of the X-ray emission from the accreting X-ray pulsars LMC X-4 and SMC X-1. These high mass X-ray binary (HMXB) sources are known to vary in a nearly periodic fashion with cycle lengths of about 30 and 60 days respectively. The prevailing model for such behavior is that it is due to the precession of a tilted accretion disk around the neutron star which is the source of the X-ray emission. As the disk precesses, it periodically obscures the emitting region, resulting in reduced flux as observed at the Earth. The obscuration is not strictly periodic, as the disk precession period changes as the total mass and size of the disk change through variable accretion processes. This model is well established for the long-period variability in the X-ray pulsar Her X-1. With this work, my collaborators and I sought to test whether this model works for LMC X-4 and SMC X-1. Observations with the pointed instruments on the Rossi X-ray Timing Explorer (RXTE) were carried out in order to observe changes in the X-ray spectrum and total flux which were correlated with the long period cycles in these objects. One of the main predictions of the precessing disk model is that the periods of low emission are caused not by changes in the central source, but by increased absorption of that flux as seen at the Earth. Such behavior would be observed in the X-ray spectrum as a relative lack of low energy X-rays (which are more easily absorbed) as compared to high energy X-rays. This is what was observed for SMC X-1, landing strong support to the precessing disk model for this system. For LMC X-1, however, the absorption was consistent with zero at the time of minimum flux. The entire spectrum appeared to be equally reduced. This is not supporting evidence for the model. However, it also does not rule out a precessing disk. If at the time of minimum flux, the intervening disk is so thick that no flux, even high energy X-rays, can penetrate, and if there is material above the disk which can scatter X-rays, then a small scattered spectrum will be seen which is indistinguishable from the unobscured source flux. This is quite possibly the case in LMC X-1.

Heindl, William A.↗
NASA NTRS1995

Molecular indicators for palaeoenvironmental change in a Messinian evaporitic sequence (Vena del Gesso, Italy). II: High-resolution variations in abundances and 13C contents of free and sulphur-bound carbon skeletons in a single marl bed

The extractable organic matter of 10 immature samples from a marl bed of one evaporitic cycle of the Vena del Gesso sediments (Gessoso-solfifera Fm., Messinian, Italy) was analyzed quantitatively for free hydrocarbons and organic sulphur compounds. Nickel boride was used as a desulphurizing agent to recover sulphur-bound lipids from the polar and asphaltene fractions. Carbon isotopic compositions (delta vs PDB) of free hydrocarbons and of S-bound hydrocarbons were also measured. Relationships between these carbon skeletons, precursor biolipids, and the organisms producing them could then be examined. Concentrations of S-bound lipids and free hydrocarbons and their delta values were plotted vs depth in the marl bed and the profiles were interpreted in terms of variations in source organisms, 13 C contents of the carbon source, and environmentally induced changes in isotopic fractionation. The overall range of delta values measured was 24.7%, from -11.6% for a component derived from green sulphur bacteria (Chlorobiaceae) to -36.3% for a lipid derived from purple sulphur bacteria (Chromatiaceae). Deconvolution of mixtures of components deriving from multiple sources (green and purple sulphur bacteria, coccolithophorids, microalgae and higher plants) was sometimes possible because both quantitative and isotopic data were available and because either the free or S-bound pool sometimes appeared to contain material from a single source. Several free n-alkanes and S-bound lipids appeared to be specific products of upper-water-column primary producers (i.e. algae and cyanobacteria). Others derived from anaerobic photoautotrophs and from heterotrophic protozoa (ciliates), which apparently fed partly on Chlorobiaceae. Four groups of n-alkanes produced by algae or cyanobacteria were also recognized based on systematic variations of abundance and isotopic composition with depth. For hydrocarbons probably derived from microalgae, isotopic variations are well correlated with those of total organic carbon. A resistant aliphatic biomacromolecule produced by microalgae is, therefore, probably an important component of the kerogen. These variations reflect changes in the depositional environment and early diagenetic transformations. Changes in the concentrations of S-bound lipids induced by variations in conditions favourable for sulphurization were discriminated from those related to variations in primary producer assemblages. The water column of the lagoonal basin was stratified and photic zone anoxia occurred during the early and middle stages of marl deposition. During the last stage of the marl deposition the stratification collapsed due to a significant shallowing of the water column. Contributions from anaerobic photoautotrophs were apparently associated with variations in depth of the chemocline.

Non-NASA Center↗
NASA NTRS2012

The Role of Lightning in Controlling Interannual Variability of Tropical Tropospheric Ozone and OH and its Implications for Climate

Nitrogen oxides (NO(x) = NO + NO2) produced by lightning make a major contribution to the production of the dominant tropospheric oxidants (OH and ozone). These oxidants control the lifetime of many trace gases including long-lived greenhouse gases, and control the source-receptor relationship of inter-hemispheric pollutant transport. Lightning is affected by meteorological variability, and therefore represents a potentially important tropospheric chemistry-climate feedback. Understanding how interannual variability (IAV) in lightning affects IAV in ozone and OH in the recent past is important if we are to predict how oxidant levels may change in a future warmer climate. However, lightning parameterizations for chemical transport models (CTMs) show low skill in reproducing even climatological distributions of flash rates from the Lightning Imaging Sensor (LIS) and the Optical Transient Detector (OTD) satellite instruments. We present an optimized regional scaling algorithm for CTMs that enables sufficient sampling of spatiotemporally sparse satellite lightning data from LIS to constrain the spatial, seasonal, and interannual variability of tropical lightning. We construct a monthly time series of lightning flash rates for 1998-2010 and 35degS-35degN, and find a correlation of IAV in total tropical lightning with El Nino. We use the IAV-constraint to drive a 9-year hindcast (1998-2006) of the GEOS-Chem 3D chemical transport model, and find the increased IAV in LNO(x) drives increased IAV in ozone and OH, improving the model fs ability to simulate both. Although lightning contributes more than any other emission source to IAV in ozone, we find ozone more sensitive to meteorology, particularly convective transport. However, we find IAV in OH to be highly sensitive to lightning NO(x), and the constraint improves the ability of the model to capture the temporal behavior of OH anomalies inferred from observations of methyl chloroform and other gases. The sensitivity of OH is explained using photochemical reaction rates which show a "magnification" effect of the initial lightning NO perturbation on OH primary production, HO(x) recycling, and OH loss frequencies. This influence on OH may represent a negative feedback, if lightning increases in a warming world..

Murray, Lee T.↗
NASA NTRS2017

Angular Normalization of GOME-2 Sun-Induced Chlorophyll Fluorescence Observation as a Better Proxy of Vegetation Productivity

Sun-induced chlorophyll fluorescence (SIF) has been regarded as a promising proxy for gross primary productivity (GPP) over land. Considerable uncertainties in GPP estimation using remotely sensed SIF exist due to variations in the Sun-satellite view observation geometry that could induce unwanted variations in SIF observation. In this study, we normalize the far-red Global Ozone Monitoring Experiment-2 SIF observations on sunny days to hot spot direction (SIF(h)) to represent sunlit leaves and compute a weighted sum of SIF (SIF(t)) from sunlit and shaded leaves to represent the canopy. We found that SIF(h) is better correlated with sunlit GPP simulated by a process-based ecosystem model and SIF(t) is better correlated with the simulated total GPP than the original SIF observations. The coefficient of determination (R(exp 2)) are increased by 0.04 +/- 0.03, and 0.07 +/- 0.04 on a global average using SIF(h) and SIF(t), respectively. The most significant increases of the R(exp 2) (0.09 +/- 0.04 for SIF(t) and 0.05 +/- 0.03 for SIF(h)) appear in deciduous broadleaf forests.

Australia↗
NASA NTRS2019

Physical Evaluation of GPM DPR Single- and Dual-Wavelength Algorithms

A physical evaluation of the rain profiling retrieval algorithms for the Dual-frequency Precipitation Radar (DPR) aboard the Global Precipitation Measurement (GPM) core satellite is carried out by applying them to the hydrometeor profiles generated from measured raindrop size distributions (DSD). The DSD-simulated radar profiles are used as input to the algorithms, and their estimates of hydrometeors' parameters are compared with the same quantities derived directly from the DSD data (or truth). The retrieval accuracy is assessed by the degree to which the estimates agree with the truth. To check the validity and robustness of the retrievals, the profiles are constructed for cases ranging from fully correlated (or uniform) to totally uncorrelated DSDs along the columns. Investigation into the sensitivity of the retrieval results to the model assumptions is made to characterize retrieval uncertainties and identify error sources. Comparisons between the single- and dual-wavelength algorithm performance are carried out with either a single- or dual-wavelength constraint of the path integral or differential path integral attenuation. The results suggest that the DPR dual-wavelength algorithm generally provides accurate range-profiled estimates of rainfall rate and mass-weighted diameter with the dual-wavelength estimates superior in accuracy to those from the single-wavelength retrievals.

Liang Liao↗
NASA NTRS2019

Understanding Martian Alteration Processes by Comparing In-Situ Chemical Measurements from Multiple Landing Sites

Characterizing the history of aqueous activity at the martian surface has been an objective of the Mars Exploration Rovers (MER) and the Mars Science Laboratory (MSL). Although the geologic context of the three landing sites are different, comparisons across the datasets can provide greater insight than using data from one mission alone. The Alpha Particle X-ray Spectrometer (APXS) is common to all three rovers (Spirit at Gusev crater, Opportunity at Meridiani Planum, and Curiosity at Gale crater) and provides a consistent basis for these comparisons. Soil and Dust: Fine grained basaltic soils and dust are remarkably uniform in chemical composition across multiple landing sites. These similarities in the concentrations of major, minor, and a few trace elements (Fig. 1) are indicative of planet-wide consistency in the composition of source materials for the soils. S and Cl vary by a factor of two in the soil and dust, but there is no clear association with any bulk cation (e.g., no correlation between S and total Ca, Mg, or Fe in soils). These volatile elements, however, are clearly associated with the nanophase-ferric iron component in the soil established by Mössbauer spectroscopy [1,2]. S and Cl likely originated as acidic species from volcanic out-gassing and subsequently coalesced on dust and sand grain surfaces, possibly with an affinity towards Fe3+ sites. Importantly, given the mobility of S and Cl in aqueous exposures, soil samples maintaining the typical molar S/Cl ratio of ~3.7:1 indicate minimal interactions with liquid water after the addition of S and Cl. In contrast to this well-established baseline, soil samples have been discovered at all three landing sites with atypical S/Cl ratios (e.g., subsurface soils), indicative of a more complex aqueous history.

Yen, A. S.↗
NASA NTRS2006

Probing the Magnetic Causes of CMEs: Free Magnetic Energy More Important Than Either Size Or Twist

To probe the magnetic causes of CMEs, we have examined three types of magnetic measures: size, twist and total nonpotentiality (or total free magnetic energy) of an active region. Total nonpotentiality is roughly the product of size times twist. For predominately bipolar active regions, we have found that total nonpotentiality measures have the strongest correlation with future CME productivity (approx. 75% prediction success rate), while size and twist measures each have a weaker correlation with future CME productivity (approx. 65% prediction success rate) (Falconer, Moore, & Gary, ApJ, 644, 2006). For multipolar active regions, we find that the CME-prediction success rates for total nonpotentiality and size are about the same as for bipolar active regions. We also find that the size measure correlation with CME productivity is nearly all due to the contribution of size to total nonpotentiality. We have a total nonpotentiality measure that can be obtained from a line-of-sight magnetogram of the active region and that is as strongly correlated with CME productivity as are any of our total-nonpotentiality measures from deprojected vector magnetograms. We plan to further expand our sample by using MDI magnetograms of each active region in our sample to determine its total nonpotentiality and size on each day that the active region was within 30 deg. of disk center. The resulting increase in sample size will improve our statistics and allow us to investigate whether the nonpotentiality threshold for CME production is nearly the same or significantly different for multipolar regions than for bipolar regions. In addition, we will investigate the time rates of change of size and total nonpotentiality as additional causes of CME productivity.

Falconer, D. A.↗
NASA NTRS1994

Contributions of a Tunable Diode Laser Instrument (ATLAS) to the Stratospheric Ozone Depletion Question

The Airborne Tunable Laser Absorption Spectrometer - ATLAS - was designed and built at the NASA Ames Research Center and operates on the NASA ER-2 high altitude research aircraft. ATLAS has taken part in a number of important polar and mid-latitude research campaigns, since 1987, focused on various aspects of stratospheric ozone chemistry and dynamics. The chief measurement carried out by the ATLAS second harmonic diode laser spectrometer is of the important atmospheric tracer N2O. Using N2O as an inert tracer we have been able to gain significant new information on polar vortex dynamics and on the correlations of several important long-lived tracers in the stratosphere. The correlation of N2O with NOy (total reactive nitrogen) has been shown to be linear for a great variety of unperturbed stratospheric conditions, and the breakdown of this correlation has been used to detect denitrification by PSCs in the polar vortex, especially in the Antarctic spring. Denitrification is an important step in the process of ozone hole formation in the austral spring. Correlations of N2O with CFCs and CH4 have led to improved estimates of atmospheric lifetimes of these important molecules. Finally the correlation of N2O with CO2, the latter now being measured with great precision by a new instrument on the ER-2, has led to a significant new tool for studying horizontal and vertical mixing in the lower stratosphere, a tool which is very useful in assessing the potential effects of high speed civil transport aircraft in the lower stratosphere. A new, light-weight version of ATLAS is currently being built for unmanned high altitude aircraft, specifically the new Perseus vehicle. We will give a brief description of this effort.

Loewenstein, Max↗
NASA NTRS2002

Materials Science Research Rack-1 Fire Suppressant Distribution Test Report

Fire suppressant distribution testing was performed on the Materials Science Research Rack-1 (MSRR-1), a furnace facility payload that will be installed in the U.S. Lab module of the International Space Station. Unlike racks that were tested previously, the MSRR-1 uses the Active Rack Isolation System (ARIS) to reduce vibration on experiments, so the effects of ARIS on fire suppressant distribution were unknown. Two tests were performed to map the distribution of CO2 fire suppressant throughout a mockup of the MSRR-1 designed to have the same component volumes and flowpath restrictions as the flight rack. For the first test, the average maximum CO2 concentration for the rack was 60 percent, achieved within 45 s of discharge initiation, meeting the requirement to reach 50 percent throughout the rack within 1 min. For the second test, one of the experiment mockups was removed to provide a worst-case configuration, and the average maximum CO2 concentration for the rack was 58 percent. Comparing the results of this testing with results from previous testing leads to several general conclusions that can be used to evaluate future racks. The MSRR-1 will meet the requirements for fire suppressant distribution. Primary factors that affect the ability to meet the CO2 distribution requirements are the free air volume in the rack and the total area and distribution of openings in the rack shell. The length of the suppressant flowpath and degree of tortuousness has little correlation with CO2 concentration. The total area of holes in the rack shell could be significantly increased. The free air volume could be significantly increased. To ensure the highest maximum CO2 concentration, the PFE nozzle should be inserted to the stop on the nozzle.

Wieland, P. O.↗
DOE OSTI2022

Ab initio study on fcc Pr with correlation matrix renormalization theory

Here, we studied fcc praseodymium (Pr) with the ab initio correlation matrix renormalization theory (CMRT) explicitly calculating the Coulomb interactions among basis orbitals and without using any adjustable parameters to work for strongly correlated electron systems. We calculated its total energy in a paramagnetic ground state and studied the role of the correlated 4f electrons in the system. Good agreement was obtained between CMRT and experiments in the pressure volume dependence of the fcc phase. We also compared the CMRT results against other theoretical methods including local density approximation + dynamical mean-field theory and showed consistent results among them. Moreover, we found the normalized local charge fluctuation of the 4f electrons as the function of volume exhibits a clear slope change at the volume collapse region, indicating a switch in their correlation nature there.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
NASA NTRS1981

Lake classification in Vermont

In order to comply with the Federal Clean Water Act and, in so doing, develop a procedure to periodically update the classification, the State of Vermont evaluated the ability of LANDSAT to detect general water quality and specific water quality parameters in Vermont lakes. Unsupervised and supervised classifications as well as regression analyses were used to examine LANDSAT data from Lake Champlain and from four small nearby lakes. Unsupervised and supervised classifications were found to be of somewhat limited value. Regression analyses revealed a good correlation between depth-integrated total phosphorus concentrations and LANDSAT band 4 data (r2= 0.92) and between Secchi disk transparencies and LANDSAT band 4 data (r2 - 0.85). No correlation was found between depth-integrated chlorophyll-a samples and LANDSAT data. Vermont is expanding this LANDSAT evaluation to include the remaining lakes in the state greater than twenty acres and steps are being taken to incorporate LANDSAT into the state's ongoing water quality monitoring programs.

Garrison, V.↗
DOE OSTI2019

SANS coupled with fluid invasion approaches for characterization of overall nanopore structure and mesopore connectivity of organic-rich marine shales in China

The pore structure of shales, including pore morphology, connectivity, pore volume, specific surface area (SSA), and pore size distribution (PSD), is a significant factor in controlling gas storage and transport and the migration mechanisms of hydrocarbons. However, the lack of comprehensive characterization for both accessible and inaccessible pore structure increases the difficulty of gas-in-place estimation and gas exploration. In order to investigate the nanoscale pore system, integration of high-pressure mercury intrusion porosimetry (MIP), low-pressure N 2 /CO 2 adsorption (LNA/LCA), and small-angle neutron scattering (SANS) were employed to obtain a multi-scale quantitative characterization of the nanopore structure of organic-rich marine shale samples from the Longmaxi and Niutitang Formations in China. In this work, PSDs obtained from the combined techniques appropriately cover an overall nanopore size range of shale (0.35–15,000 nm) and overcome the limits of the individual method. Uni-, bi, and multi-modal PSDs were observed, but the sizes of a significant portion of the nanopores observed in these shales range from 0.35 to 100 nm. Pore volumes and surface areas of micropores (<2 nm), mesopores (2–50 nm), and macropores (>50 nm) were characterized based on the best performance window of each technique: LCA for micropores; LNA and SANS for mesopores; and MIP for macropores. It was found that micropores are the major contributor to the total SSA for both the Longmaxi and Niutitang shales. With respect to pore volume, however, the contribution to the total pore volume has a trend of micropore < mesopore < macropore for the Longmaxi shale samples, but micro-/mesopore volumes are greater than macropore volumes for samples of the Niutitang shale. Strong correlations were also observed between total organic carbon (TOC) content and micropore volume and surface area, which implies that organic matter is a controlling factor in the micropore system of organic-rich shales. In addition, strong correlations between methane adsorption capacity and both micro-/mesopore volumes and SSAs indicate that micro-/mesopores are governing factors for methane storage. Furthermore, the fractions of accessible mesopore volume and surface area were quantitatively estimated by SANS and LNA. Correlation analyses suggest that the accessibility of the mesopore surface area could be an indicator for gas transport and storage in mesopores in organic matter. Thus, a shale with higher connectivity could have higher gas diffusion capability but lower gas adsorption capacity, and vice versa.

58 GEOSCIENCES↗
DOE OSTI2020

Operational-based annual energy production uncertainty: are its components actually uncorrelated?

Calculations of annual energy production (AEP) from a wind power plant – whether based on preconstruction or operational data – are critical for wind plant financial transactions. The uncertainty in the AEP calculation is especially important in quantifying risk and is a key factor in determining financing terms. A popular industry practice is to assume that different uncertainty components within an AEP calculation are uncorrelated and can therefore be combined as the sum of their squares. We assess the practical validity of this assumption for operational-based uncertainty by performing operational AEP estimates for more than 470 wind plants in the United States, mostly in simple terrain. We apply a Monte Carlo approach to quantify uncertainty in five categories: revenue meter data, wind speed data, regression relationship between density-corrected wind speed (from reanalysis data) and measured wind power, length of long-term-correction data set, and future interannual variability. We identify correlations between categories by comparing the results across all 470 wind plants. We observe a positive correlation between interannual variability and the linearized long-term correction; a negative correlation between wind resource interannual variability and linear regression; and a positive correlation between reference wind speed uncertainty and linear regression. Then, we contrast total operational AEP uncertainty values calculated by omitting and considering correlations between the uncertainty components. We quantify that ignoring these correlations leads to an underestimation of total AEP uncertainty of, on average, 0.1% and as large as 0.5% for specific sites. Although these are not large increases, these would still impact wind plant financing rates; further, we expect these values to increase for wind plants in complex terrain. Based on these results, we conclude that correlations between the identified uncertainty components should be considered when computing the total AEP uncertainty.

17 WIND ENERGY↗
NASA NTRS2004

The M Solar Mass - L(sub bulge) Correlation

New detections of supermassive black hole (BH) candidates are used to update the observed correlation between BH mass M and the luminosity L(sub bulge) of the bulge component of the host galaxy. Our main purpose is to test whether the correlation is real or just the upper envelope of a distribution that extends to smaller Solar Mass. We also illustrate the following conclusions: 1 -- BH mass correlates much better with bulge luminosity than with the total luminosity of the galaxy. 2 -- BH mass correlates with the luminosity of the high-density central component in disk galaxies independent of whether that component is a classical bulge (essentially a mini-elliptical) or a pseudobulge (believed to form via inward transport of disk material). This conclusion is based on only three pseudobulges, so it needs to be checked. 3 -- The BH mass correlates with the velocity dispersion of the bulge component outside the region influenced by the BH. That is, it correlates with the depth of the potential well in which it lives. Our conclusions are consistent with the hypothesis that (pseudo)bulge formation and BH feeding are closely connected. To first order, present data do not show any dependence of M\bullet on the details of whether BH feeding happens rapidly during a collapse or slowly via secular evolution of the disk.

Kormendy, J.↗
NASA NTRS1975

Application of LANDSAT to the Surveillance and Control of Lake Eutrophication in the Great Lakes Basin

The author has identified the following significant results. Computer techniques developed for mapping water quality parameters from LANDSAT data were demonstrated, using ground truth collected in an ongoing survey of water quality in Saginaw Bay (Lake Huron), Michigan. Regression correlation coefficients varied from 0.99 for total phosphorus to 0.72 for chlorophyll-a corrected. Five water quality parameters are best correlated with LANDSAT band 6 alone. Temperature relates to band 5 alone and only two bands are justified for mapping the remaining six parameters. LANDSAT CCTs were used as a basis for inventorying land use within each of the Ohio-Kentucky-Indiana regional commissions, 225 drainage areas, and nine counties. Sixteen categories were merged into ten categories and mapped at a scale of 1 in. = 5,000 ft, with detail to 0.44 hectares for the 2,700 sq mi region. These products were produced in less than 90 days at a cost of one cent an acre. LANDSAT CCTS were also used as a basis for inventorying land cover within the Triangle J council of governments 1,750 sq mi study area. The complete inventory was accomplished within a period of 60 days at a cost of about one half cent per acre.

Rogers, R. H.↗