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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 991 records · Page 55

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NASA NTRS1974

Energy recovery from solid waste

A recent group study on the problem of solid waste disposal provided a decision making model for a community to use in determining the future for its solid waste. The model is a combination of the following factors: technology, legal, social, political, economic and environmental. An assessment of local or community needs determines what form of energy recovery is desirable. A market for low pressure steam or hot water would direct a community to recover energy from solid waste by incineration to generate steam. A fuel gas could be produced by a process known as pyrolysis if there is a local market for a low heating value gaseous fuel. Solid waste can also be used directly as a fuel supplemental to coal in a steam generator. An evaluation of these various processes is made.

Dalton, C.↗

NASA NTRS1976

Effects of environmental changes on marsh vegetation with special reference to salinity

A literature survey primarily concerned with brackish and salt marshes located along the eastern coast of North America and the Gulf Coast was presented. The review concentrated upon the vegetation of the marshes, particularly in regard to distribution, composition, succession, and productivity. Special efforts were made to include major works concerned with the Louisiana and Mississipi coastal marshes. It appears that spring to early summer (weeks 18-34 of the year; April - mid-July) is the best period of time to categorize the communities. It is during this time of the year that the communities appear most stable in regard to species composition. This allows a strong correlation to be drawn between the salinity of the region and the dominant species of the community. As such, this would seem to be best period in which to sample the marsh via air or land for differences in vegetation and salinity.

Smalley, A. E.↗

NASA NTRS1976

Definition of performance specifications for automated Analytical Electrophoresis Facility (AAEF)

In order to provide specifications for the automated Analytical Electrophoresis Facility (AAEF) that would satisfy the broadest variety of demands of a future user community, a survey was carried out of all those people who were identified as having published papers on cell electrophoresis in the past four years. A computer search was conducted of the relevant literature from which a list of 87 investigators was derived and defined as the user community for purposes of the mailing. A questionnaire was developed covering the areas of performance which required definition which was subsequently circulated to the user community. Based on the response to this survey performance specifications were assembled.

Brooks, D. E.↗

NASA NTRS1979

Description of photovoltaic village power systems in the United States and Africa

Photovoltaic power systems in remote villages in the United States and Africa are described. These projects were undertaken to demonstrate that existing photovoltaic system technology is capable of providing electrical power for basic domestic services for the millions of small, remote communities in both developed and developing countries. One system is located in the Papago Indian Village of Schuchuli in southwest Arizona (U. S.) and became operational 16 December 1978. The other system is located in Tangaye, a rural village in Upper Volta, Africa. It became operational 1 March 1979. The Schuchuli system has a 3.5 kW (peak) solar array which provides electric power for village water pumping, a refrigerator for each family, lights in the village buildings, and a community washing machine and sewing machine. The 1.8 kW (peak) Tangaye system provides power for community water pumping, flour milling and lights in the milling building. These are both stand-alone systems (i.e., no back-up power source) which are being operated and maintained by local personnel. Both systems are instrumented. Systems operations are being monitored by NASA to measure design adequacy and to refine designs for future systems.

Ratajczak, A. F.↗

NASA NTRS1981

Planning for rotorcraft and commuter air transportationn

Community planning needs, criteria, and other considerations such as intermodal coordination and regulatory requirements, for rotorcraft and fixed wing commuter air transportation were identified. A broad range of community planning guidelines, issues, and information which can be used to: (1) direct anticipated aircraft technological improvements; (2) assist planners in identifying and evaluating the opportunities and tradeoffs presented by rotorcraft and commuter aircraft options relative to other modes; and (3) increase communication between aircraft technologists and planners for the purpose of on going support in capitalizing on rotorcraft and commuter air opportunities are provided. The primary tool for identifying and analyzing planning requirements was a detailed questionnaire administered to a selected sample of 55 community planners and other involved in planning for helicopters and commuter aviation.

Stockwell, W. L.↗

NASA NTRS1984

Materials properties data base computerization

Material property data plays a key role in the design of jet engine components. Consistency, accuracy and efficient use of material property data is of prime importance to the engineering community. The system conception, development, implementation, and future plans for computer software that captures the Material Properties Handbook into a scientific data base are described. The engineering community is given access to raw data and property curves, display of multiple curves for material evaluation and selection, direct access by design analysis computer programs, display of the material specification, and a historical repository for the material evolution. The impact of this activity includes significant productivity gains and cost reductions; all users have access to the same information nd provides consistent, rapid response to the needs of the engineering community. Future plans include incorporating the materials properties data base into a network environment to access information from other data bases and download information to engineering work stations.

Baur, R. G.↗

NASA NTRS1985

The space shuttle ascent vehicle aerodynamic challenges configuration design and data base development

The phase B Space Shuttle systems definition studies resulted in a generic configuration consisting of a delta wing orbiter, and two solid rocket boosters (SRB) attached to an external fuel tank (ET). The initial challenge facing the aerodynamic community was aerodynamically optimizing, within limits, this configuration. As the Shuttle program developed and the sensitivities of the vehicle to aerodynamics were better understood the requirements of the aerodynamic data base grew. Adequately characterizing the vehicle to support the various design studies exploded the size of the data base to proportions that created a data modeling/management challenge for the aerodynamicist. The ascent aerodynamic data base originated primarily from wind tunnel test results. The complexity of the configuration rendered conventional analytic methods of little use. Initial wind tunnel tests provided results which included undesirable effects from model support tructure, inadequate element proximity, and inadequate plume simulation. The challenge to improve the quality of test results by determining the extent of these undesirable effects and subsequently develop testing techniques to eliminate them was imposed on the aerodynamic community. The challenges to the ascent aerodynamics community documented are unique due to the aerodynamic complexity of the Shuttle launch. Never before was such a complex vehicle aerodynamically characterized. The challenges were met with innovative engineering analyses/methodology development and wind tunnel testing techniques.

Dill, C. C.↗

NASA NTRS1985

Remote sensing of stressed vegetation in the Carolina slate belt

Remote sensing techniques have been used to detect stress in vegetation, but they have not been very successful for identifying which environmental factors cause the vegetation to appear stressed. Controlled comparisons of spectral characteristics of plant communities experiencing known combinations of stresses were designed to examine this problem. Landsat TM, NS-001 TMS, CIR, and AIS imagery was acquired for six stressed areas in the Carolina slate belt. Preliminary results indicated that the areas of stressed vegetation were identifiable, and that the stressed communities appeared to be undergoing early fall leaf senescence. The AIS data seemed to have the greatest potential for identifying differences among plant community spectra, but calibration will be necessary before these differences can be evaluated.

Wickland, D. E.↗

NASA NTRS1986

MST data exchange through the NCAR incoherent-scatter radar data base

One means of making MST (mesosphere stratosphere troposphere) radar data more easily accessible for scientific research by the general scientific community is through a centralized data base. Such a data base can be designed to readily provide information on data availability and quality, and to provide copies of data from any radar in a common format to the user. The ionospheric incoherent scatter community has established a centralized data base at NCAR that may serve not only as a model for a possible MST data base, but also as a catalyst for getting an MST data base started. (Some key elements of the NCAR data base are given.) The NCAR data base can include MST data in the same framework with relatively little extra effort. They are willing to handle MST data on a limited basis in order to permit assessment of community interest and in order to provide some experience with a centralized data base for MST data.

Richmond, A. D.↗

NASA NTRS1985

Effects of space shuttle launches STS-1 through STS-9 on terrestrial vegetation of John F. Kennedy Space Center, Florida

Space Shuttle launches produce a cloud containing hydrochloric acid (HCl), aluminum oxide (Al203), and other substances. Acidities of less than 0.5 pH have been measured routinely in association with the launch cloud. In an area of about 22 ha regularly exposed to the exhaust cloud during most Shuttle launches, acute vegetation damage has resulted from the first nine Shuttle launches. Changes include loss of sensitive species, loss of plant community structure, reduction in total cover, and replacement of some species by weedy invaders. Community level changes define a retrogressive sequence. One-time impacts to strand and dune vegetation occurred after launches of STS-8 and STS-9. Acute vegetation damage occurred especially to sensitive species. Within six months, however, recovery was nearly complete. Sensitivity of species to the launch cloud was partially predicted by previous laboratory studies. Far-field acidic and dry fallout from the cloud as it rises to stabilization and moves with the prevailing winds causes vegetation spotting. Damage from this deposition is minor; typically at most 1% to 5% of leaf surface area is affected. No plant mortality or community changes have occurred from far-field deposition.

Schmalzer, P. A.↗

NASA NTRS1987

Landscape pattern and successional dynamics in the boreal forest

The landscape-scale community dynamics of a boreal forest ecosystem was investigated using the Landsat MSS data record form 1973 to 1983 to generate a stochastic description of the key life cycle states of the community landscape elements. Such descriptions can provide input and verification for models of community development and landscape dynamics. It is anticipated that the proposed approach may be extended to measure, monitor, and model ecosystems at continental and planetary scales.

Hall, Forrest G.↗

NASA NTRS1986

Recent trends in geographic information system research

This paper reviews recent contributions to the body of published research on Geographic Information Systems (GISs). Increased usages of GISs have placed a new demand upon the academic and research community and despite some lack of formalized definitions, categorizations, terminologies, and standard data structures, the community has risen to the challenge. Examinations of published GIS research, in particular on GIS data structures, reveal a healthy, active research community which is using a truly interdisciplinary approach. Future work will undoubtably lead to a clearer understanding of the problems of handling spatial data, while producing a new generation of highly sophisticated GISs.

Clarke, K. C.↗

NASA NTRS1989

Acoustic evaluation of the Helmholtz resonator treatment in the NASA Lewis 8- by 6-foot supersonic wind tunnel

The acoustic consequences of sealing the Helmholtz resonators of the NASA Lewis 8- by 6-Foot Supersonic Wind Tunnel (8x6 SWT) were experimentally evaluated. This resonator sealing was proposed in order to avoid entrapment of hydrogen during tests of advanced hydrogen-fueled engines. The resonators were designed to absorb energy in the 4- to 20-Hz range; thus, this investigation is primarily concerned with infrasound. Limited internal and external noise measurements were made at tunnel Mach numbers ranging from 0.5 to 2.0. Although the resonators were part of the acoustic treatment installed because of a community noise problem their sealing did not seem to indicate a reoccurrence of the problem would result. Two factors were key to this conclusion: (1) A large bulk treatment muffler downstream of the resonators was able to make up for much of the attenuation originally provided by the resonators, and (2) there was no noise source in the tunnel test section. The previous community noise problem occurred when a large ramjet was tested in an open-loop tunnel configuration. If a propulsion system producing high noise levels at frequencies of less than 10 Hz were tested, the conclusion on community noise would have to be reevaluated.

Heidelberg, Laurence J.↗

NASA NTRS1989

Microbial mats in playa lakes and other saline habitats: Early Mars analog?

Microbial mats are cohesive benthic microbial communities which inhabit various Terra (Earth-based) environments including the marine littoral and both permanent and ephemeral (playa) saline lakes. Certain geomorphological features of Mars, such as the Margaritifer Sinus, were interpreted as ancient, dried playa lakes, presumably formed before or during the transition to the present Mars climate. Studies of modern Terran examples suggest that microbial mats on early Mars would have had the capacity to survive and propagate under environmental constraints that would have included irregularly fluctuating regimes of water activity and high ultraviolet flux. Assuming that such microbial communities did indeed inhabit early Mars, their detection during the Mars Rover Sample Return (MRSR) mission depends upon the presence of features diagnostic of the prior existence of these communities or their component microbes or, as an aid to choosing suitable landing, local exploration or sampling sites, geomorphological, sedimentological or chemical features characteristic of their playa lake habitats. Examination of modern Terran playas (e.g., the Lake Eyre basin) shows that these features span several orders of magnitude in size. While stromatolites are commonly centimeter-meter scale features, bioherms or fields of individuals may extend to larger scales. Preservation of organic matter (mats and microbes) would be favored in topographic lows such as channels or ponds of high salinity, particularly those receiving silica-rich groundwaters. These areas are likely to be located near former zones of groundwater emergence and/or where flood channels entered the paleo-playa. Fossil playa systems which may aid in assessing the applicability of this particular Mars analog include the Cambrian Observatory Hill Beds of the Officer Basin and the Eocene Wilkins Peak Member of the Green River Formation.

Bauld, John↗

NASA NTRS1989

The geological record of life 3500 Ma ago: Coping with the rigors of a young earth during late accretion

Thin cherty sedimentary layers within the volcanic portions of the 3,500 to 3,300 Ma-old Onverwacht and Fig Tree Groups, Barberton Greenstone belt, South Africa, and Warrawoona Group, eastern Pilbara Block, Western Australia, contain an abundant record of early Archean life. Five principal types of organic and probably biogenic remains and or structures can be identifed: stromatolites, stromatolite detritus, carbonaceous laminite or flat stromalite, carbonaceous detrital particles, and microfossils. Early Archean stromatolites were reported from both the Barberton and eastern Pilbara greenstone belts. Systematic studies are lacking, but two main morphological types of stromatolites appear to be represented by these occurrences. Morphology of the stromalites is described. Preserved early Archean stromatolites and carbonaceous matter appear to reflect communities of photosynthetic cyanobacteria inhabiting shallow, probably marine environments developed over the surfaces of low-relief, rapidly subsiding, simatic volcanic platforms. The overall environmental and tectonic conditions were those that probably prevailed at Earth's surface since the simatic crust and oceans formed sometime before 3,800 Ma. Recent studies also suggest that these early Archean sequences contain layers of debris formed by large-body impacts on early Earth. If so, then these early bacterial communities had developed strategies for coping with the disruptive effects of possibly globe-encircling high-temperature impact vapor clouds, dust blankets, and impact-generated tsunamis. It is probable that these early Archean biogenic materials represent organic communities that evolved long before the beginning of the preserved geological record and were well adapted to the rigors of life on a young, volcanically active Earth during late bombardment. These conditions may have had parallels on Mars during its early evolution.

Lowe, Donald R.↗

NASA NTRS1988

NASA's unique networking environment

Networking is an infrastructure technology; it is a tool for NASA to support its space and aeronautics missions. Some of NASA's networking problems are shared by the commercial and/or military communities, and can be solved by working with these communities. However, some of NASA's networking problems are unique and will not be addressed by these other communities. Individual characteristics of NASA's space-mission networking enviroment are examined, the combination of all these characteristics that distinguish NASA's networking systems from either commercial or military systems is explained, and some research areas that are important for NASA to pursue are outlined.

Johnson, Marjory J.↗

NASA NTRS1989

[NASA/DOD Aerospace Knowledge Diffusion Research Project. Report 3:] Technical communications in aeronautics: Results of an exploratory study. An analysis of profit managers' and nonprofit managers' responses

Data collected from an exploratory study concerned with the technical communications practices of aerospace engineers and scientists were analyzed to test the primary assumption that profit and nonprofit managers in the aerospace community have different technical communications practices. Five assumptions were established for the analysis. Profit and nonprofit managers in the aerospace community were found to have different technical communications practices for one of the five assumptions tested. It was, therefore, concluded that profit and nonprofit managers in the aerospace community do not have different technical communications practices.

Pinelli, Thomas E.↗

NASA NTRS1990

Concept development of a Mach 4 high-speed civil transport

A study was conducted to configure and analyze a 250 passenger, Mach 4 High Speed Civil Transport with a design range of 6500 n.mi. The design mission assumed an all-supersonic cruise segment and no community noise or sonic boom constraints. The study airplane was developed in order to examine the technology requirements for such a vehicle and to provide an unconstrained baseline from which to assess changes in technology levels, sonic boom limits, or community noise constraints in future studies. The propulsion, structure, and materials technologies utilized in the sizing of the study aircraft were assumed to represent a technology availability date of 2015. The study airplane was a derivative of a previously developed Mach 3 concept and utilized advanced afterburning turbojet engines and passive airframe thermal protection. Details of the configuration development, aerodynamic design, propulsion system, mass properties, and mission performance are presented. The study airplane was estimated to weigh approx. 866,000 lbs. Although an aircraft of this size is a marginally acceptable candidate to fit into the world airport infrastructure, it was concluded that the inclusion of community noise or sonic boom constraints would quickly cause the aircraft to grow beyond acceptable limits using the assumed technology levels.

Domack, Christopher S.↗