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NASA NTRS1981

Cost Analysis of an Air Brayton Receiver for a Solar Thermal Electric Power System in Selected Annual Production Volumes

Pioneer Engineering and Manufacturing Company estimated the cost of manufacturing and Air Brayton Receiver for a Solar Thermal Electric Power System as designed by the AiResearch Division of the Garrett Corporation. Production costs were estimated at annual volumes of 100; 1,000; 5,000; 10,000; 50,000; 100,000 and 1,000,000 units. These costs included direct labor, direct material and manufacturing burden. A make or buy analysis was made of each part of each volume. At high volumes special fabrication concepts were used to reduce operation cycle times. All costs were estimated at an assumed 100% plant capacity. Economic feasibility determined the level of production at which special concepts were to be introduced. Estimated costs were based on the economics of the last half of 1980. Tooling and capital equipment costs were estimated for ach volume. Infrastructure and personnel requirements were also estimated.

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NASA NTRS1983

The distribution and annual cycle of ozone in the upper stratosphere

Study of the global distribution of upper stratospheric ozone derived from backscatter ultraviolet (BUV/SBUV) instruments on the Nimbus 4 and 7 satellites reveals the following characteristics for the period June 1970 May 1972 plus portions of 1978 and 1979. At pressures less than 5 mbar a local midlatitude maximum in the ozone mixing ratio develops in autumn and persists through the winter season in both hemispheres. However, by a pressure of 10 mbar the seasonal trend has reversed, with midlatitude summer values exceeding those in winter. The largest ozone mixing ratios in a global sense occur at tropical latitudes between pressures of 7 and 9 mbar. The general character of this pattern repeats from year to year, although differences in detail exist, especially in winter. This interannual variability in ozone increases the difficulty in extracting small long-term trends from the available data base. The overall seasonal pattern revealed by the measurements is in accord with photochemical model predictions which include the annual variation in temperature and solar illumination.

Frederick, J. E.↗

NASA NTRS1984

First estimate of annual mercury flux at the Kilauea main vent

Mercury and sulphur dioxide analyses were conducted from 1971 to 1980 on air samples collected immediately downwind of Halemaumau, the Kilauea main vent, in Hawaii. On the basis of these measurements, an Hg/SO2 ratio of 0.00051 has been derived which, when applied to the recently determined SO2 mass output of Halemaumau, yields a calculated Hg flux of 2.6 x 10 to the 8th g annually. This rate is consistent with Varekamp and Busek's (1981) evidence suggesting that volcanogenic Hg significantly contributes to the atmospheric total.

Siegel, S. M.↗

NASA NTRS1984

Response of the annual and zonal mean winds and temperatures to variations in the heat and momentum sources

Comparisons are made among solutions to zonal-mean equations obtained with parameterized friction and radiative cooling and those forced from specified heat and momentum sources. Budget equations are defined for zonally averaged steady state responses in a thin spherically rotating atmosphere. The heat sources and sinks and mean meridional circulation that maintain observed annual and zonal mean temperatures are identified with a diagnostic calculation. Estimates are made of the surface sensible heating, atmospheric latent heating and vertical flux eddy divergences. The heat and moisture sources and sinks are varied to obtain the steady state responses. The Hadley circulation is fairly insensitive to changes in the strength of the eddy momentum flux when sufficient internal friction is present. Varying the width of the total precipitation of the intertropical convergence zone with fixed eddy fluxes and extratropical heat sources yields conditions similar to El Nino. Finally, a minimum speed is found for the jet stream after varying the horizontal eddy momentum fixing latent and eddy heat sources.

Schneider, E. K.↗

NASA NTRS1984

Remote sensing of biomass and annual net aerial primary productivity of a salt marsh

Net aerial primary productivity is the rate of storage of organic matter in above-ground plant issues exceeding the respiratory use by the plants during the period of measurement. It is pointed out that this plant tissue represents the fixed carbon available for transfer to and consumption by the heterotrophic organisms in a salt marsh or the estuary. One method of estimating annual net aerial primary productivity (NAPP) required multiple harvesting of the marsh vegetation. A rapid nondestructive remote sensing technique for estimating biomass and NAPP would, therefore, be a significant asset. The present investigation was designed to employ simple regression models, equating spectral radiance indices with Spartina alterniflora biomass to nondestructively estimate salt marsh biomass. The results of the study showed that the considered approach can be successfully used to estimate salt marsh biomass.

Hardisky, M. A.↗

NASA NTRS1985

Contribution of stratospheric winds to annual and semiannual fluctuations in atmospheric angular momentum and the length of day

It is pointed out that modern data sets pertaining to the motions of the solid earth and the atmosphere have begun to achieve an accuracy sufficient to justify renewed interest in the classic problem of explaining variations in the rotation rate of the earth. The possibility exists that deficiencies in the current meteorological data sets account for most of the discrepancies in the annual and semiannual earth-atmosphere momentum budgets. On the basis of composite stratospheric wind analyses produced by Belmont et al. (1974), it has been demonstrated that the seasonal components of the stratosphere's momentum could contribute significantly to a reduction of the seasonal discrepancies thought to exist in the earth-atmosphere momentum budget. The present investigation is further concerned with this subject. A newly available stratospheric wind data set is utilized in conjunction with concurrent U.S. National Meteorological Center data and data of the European Centre for Medium Range Weather Forecasts.

Rosen, R. D.↗

NASA NTRS1986

Proceedings of the 2nd Annual SCOLE Workshop

Proceedings of the Second Annual Spacecraft Control Laboratory Experiment (SCOLE) Workshop held at the NASA Langley Research Center, Hampton, Va., December 9 to 10, 1985 are presented.

Taylor, L. W., Jr.↗

NASA NTRS1986

Atmospheric lifetime and annual release estimates for CFCl3 and CF2Cl2 from 5 years of ALE data

CFCl3 and CF2Cl2 data for the 5-year period from July 1978-June 1983 are analyzed. The lifetime estimates are updated using the trend technique and the annual global release rates of the gases are derived. The effects of release uncertainties on lifetime estimates are examined by studying fluorocarbon data. It is observed that in 1981 the mixing ratios for CFCl3 and CF2Cl2 displayed increases of 8.8. and 15.3 pptv/year respectively, and the trend lifetime for CFCl13 is 74 + 31 or - 17 years and for CF2Cl2 111 + 222 or - 44 years.

Cunnold, D. M.↗

NASA NTRS1987

Observations of annual and El Nino thermal and flow variations at 0 deg, 110 deg W and 0 deg, 95 deg W during 1980-1985

The paper describes the low-frequency (i.e., time scales longer than a month) upper ocean (above 250 m) current and temperature moored measurements conducted from March 1980 to September 1985 at 0, 110 deg W and from July 1981 to November 1983 (i.e., including the period of the 1982-1983 El Nino) at 0, 95 deg W. Estimates of the annual cycle were removed from the observations to determine the current and temperature fluctuations due to the 1982-1983 El Nino. The circulation of the upper ocean was found to be dramatically altered during the El Nino: the normally westward flowing surface current in autumn months reversed direction, and the equatorial undercurrent, normally considered to be a permanent feature, disappeared. Associated with the El Nino was a massive redistribution of heat throughout the mixed layer and the thermocline.

Halpern, David↗

NASA NTRS1987

Research and technology 1987 annual report of the Kennedy Space Center

As the NASA Center responsible for assembly, checkout, servicing, launch, recovery, and operational support of Space Transportation System elements and payloads, Kennedy Space Center is placing increasing emphasis on the Center's research and technology program. In addition to strengthening those areas of engineering and operations technology that contribute to safer, more efficient, and more economical execution of our current mission, we are developing the technological tools needed to execute the Center's mission relative to future programs. The Engineering Development Directorate encompasses most of the laboratories and other Center resources that are key elements of research and technology program implementation, and is responsible for implementation of the majority of the projects of this Kennedy Space Center 1987 Annual Report.

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NASA NTRS1988

Annual cycle, quasi-biennial oscillation, and Southern Oscillation in global precipitation

Using 80 years (1901-1980) of global station rainfall data, the spatial and temporal variations in global precipitation associated with the annual cycle (AC), the tropospheric quasi-biennial oscillation (QBO), and southern oscillation (SO, defined as the background 3- to 7-year fluctuation in which the El Nino events are embedded) were investigated. It was found that the dominant global precipitation pattern fluctuates irregularly, with 2- to 5-year periods associated with the SO. The temporal variation shows, in addition to the SO time scale, a distinct QBO signal. The best correlation occurred during the El Nino SO, with an apparent phase locking between the QBO and SO. The role of the possible influence of the AC and other factors involved in the QBO interaction is discussed.

Lau, K.-M.↗

NASA NTRS1988

Proceedings of the 4th Annual SCOLE Workshop

This publication is a collection of papers presented at the Fourth Annual Spacecraft Control Laboratory Experiment (SCOLE) Workshop held at the U.S.A.F. Academy, Colorado Springs, Colorado, November 16, 1987. The papers address the modeling, systems identification, and control synthesis for the Spacecraft Control Laboratory Experiment (SCOLE) configuration.

Taylor, Lawrence W., Jr.↗

NASA NTRS1988

Second Annual Workshop on Space Operations Automation and Robotics (SOAR 1988)

Papers presented at the Second Annual Workshop on Space Operation Automation and Robotics (SOAR '88), hosted by Wright State University at Dayton, Ohio, on July 20, 21, 22, and 23, 1988, are documented herein. During the 4 days, approximately 100 technical papers were presented by experts from NASA, the USAF, universities, and technical companies. Panel discussions on Human Factors, Artificial Intelligence, Robotics, and Space Systems were held but are not documented herein. Technical topics addressed included knowledge-based systems, human factors, and robotics.

Griffin, Sandy↗

NASA NTRS1988

Agenda of the Fourth Annual Summer Conference, NASA/USRA University Advanced Design Program

Presentations given by the participants at the fourth annual summer conference of the NASA/USRA University Advanced Design Program are summarized. The study topics include potential space and aeronautics projects which could be undertaken during a 20 to 30 year period beginning with the Space Station Initial Operating Configuration (IOC) scheduled for the early to mid-1990's. This includes system design studies for both manned and unmanned endeavors; e.g., lunar launch and landing facilities and operations, variable artificial gravity facility for the Space Station, manned Mars aircraft and delivery system, long term space habitat, construction equipment for lunar bases, Mars oxygen production system, trans-Pacific high speed civil transport, V/STOL aircraft concepts, etc.

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NASA NTRS1990

Third Annual Workshop on Space Operations Automation and Robotics (SOAR 1989)

Papers presented at the Third Annual Workshop on Space Operations Automation and Robotics (SOAR '89), hosted by the NASA Lyndon 8. Johnson Space Center at Houston, Texas, on July 25-27, 1989, are documented herein. During the three days, approximately 100 technical papers wer3 presented by experts from NASA, the USAF, universities, and technical companies. Also held were panel discussions on Air Force/NASA AI Overview and Expert System Verification and Validation. Tutorial sessions included Neural Networks; Theory and Application of Back Propagation; Verification and Validation of Expert Systems/ Evaluation of Expert System Tools; and Technical Environment for Modular Architectures for Robotics in Space; and are not documented herein. Technical topics addressed included intelligent systems, robotics, human factors, and environment.

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NASA NTRS1991

The 1990 annual statistics and highlights report

The National Space Science Data Center (NSSDC) has archived over 6 terabytes of space and Earth science data accumulated over nearly 25 years. It now expects these holdings to nearly double every two years. The science user community needs rapid access to this archival data and information about data. The NSSDC has been set on course to provide just that. Five years ago the NSSDC came on line, becoming easily reachable for thousands of scientists around the world through electronic networks it managed and other international electronic networks to which it connected. Since that time, the data center has developed and implemented over 15 interactive systems, operational nearly 24 hours per day, and is reachable through DECnet, TCP/IP, X25, and BITnet communication protocols. The NSSDC is a clearinghouse for the science user to find data needed through the Master Directory system whether it is at the NSSDC or deposited in over 50 other archives and data management facilities around the world. Over 13,000 users accessed the NSSDC electronic systems, during the past year. Thousands of requests for data have been satisfied, resulting in the NSSDC's sending out a volume of data last year that nearly exceeded a quarter of its holdings. This document reports on some of the highlights and distribution statistics for most of the basic NSSDC operational services for fiscal year 1990. It is intended to be the first of a series of annual reports on how well NSSDC is doing in supporting the space and Earth science user communities.

Green, James L.↗

NASA NTRS1991

How large is the retrograde annual wobble?

Recent measurements of polar motion (wobble) made by space-geodetic methods are compared with older optical measurements. Multitaper spectra of these data show that the retrograde (clockwise) annual wobble is much larger in the older data than the newer data, implying systematic errors in the older techniques. Two additional analyses show evidence for a small retrograde motion in the newer data, which appears to be consistent between data types. This implies that the excitation of the retrograde wobble must be about half of the prograde excitation. None of the available estimates of the excitation shows full agreement with these observations.

King, N. E.↗

NASA NTRS1991

Program and Abstracts for Clay Minerals Society 28th Annual Meeting

This volume contains abstracts that were accepted for presentation at the annual meeting. Some of the main topics covered include: (1) fundamental properties of minerals and methods of mineral analysis; (2) surface chemistry; (3) extraterrestrial clay minerals; (4) geothermometers and geochronometers; (5) smectite, vermiculite, illite, and related reactions; (6) soils and clays in environmental research; (7) kaolinite, halloysite, iron oxides, and mineral transformations; and (8) clays in lakes, basins, and reservoirs.

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