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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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A matrix Fredholm integral equation of neuronal networks is transformed into a Cauchy system suited for numerical and analytical studies. A special case is discussed, and a connection with the classical renewal integral equation of stochastic point processes is presented.
Efforts to develop a near sonic transport have placed renewed emphasis on obtaining accurate aerodynamic force and pressure data in the near sonic speed range. Comparison of wind-tunnel and flight data obtained for a blunt-nose body of revolution showed significant discrepancies in drag levels near Mach 1 - apparently due to wind-tunnel wall interference. Subsequent tests of geometrically similar bodies of revolution showed that increasing the model-to-test-section blockage ratio from 0.00017 to 0.0043 resulted in altered drag curve shapes, delayed drag divergence, and 'transonic creep' from subsonic drag levels due to increased wall interference.
The activities of the U.S. Department of Interior which have benefited from ERTS-1 data are described. It is stated that the primary interest is in the area of land use. Legislative actions regarding land use are reported. Programs involving renewable resources are stressed.
Solar energy, being a non-depleting clean source of energy, is shown to be capable of providing energy in all the forms in which it is used today. It can be used to generate electricity, for heating and cooling buildings, and for producing clean renewable gaseous, liquid and solid fuel. There is little question of the technical feasibility for utilizing solar energy. The chief problem is rapidly providing innovative solutions that are economically competititive with other systems.
The role is described that solar energy will play in the heating and cooling of buildings, the production of renewable gaseous, liquid and solid fuels, and the production of electric power over the next 45 years. Potential impacts on the various energy markets and estimated costs of such systems are discussed along with illustrations of some of the processes to accomplish the goals. The conclusions of the NSF/NASA Solar Energy Panel (1972) are given along with the estimated costs to accomplish the 15 year recommended program and also the recent and near future budget appropriations and recommendations are included.
After nearly two decades of study, analysis, and experiments relating to lightweight mobile nuclear power systems (LMNPS), it seems fitting to report the status and to assess some options for the future of this technology. This report: (1) reviews the technical feasibility studies of LMNPS and airborne vehicles; (2) identifies what remains to be done to demonstrate technical feasibility of LMNPS; (3) reviews missions studies and identifies particular missions that could justify renewed support for such technology; and (4) identifies some of the nontechnical conditions that will be required for the development and eventual use of LMNPS.
The role of solar energy is visualized in the heating and cooling of buildings, in the production of renewable gaseous, liquid and solid fuels, and in the production of electric power over the next 45 years. Potential impacts of solar energy on various energy markets, and estimated costs of such solar energy systems are discussed. Some typical solar energy utilization processes are described in detail. It is expected that at least 20% of the U.S. total energy requirements by 2020 will be delivered from solar energy.
The available data on the space and time structure of the radio echoes from different clouds is examined. On the basis of their analysis, a basis is given for the optimal form of presentation and the operational quality of renewal of radar information used for operational purposes in ZGMO and the TGMTs.
The role of satellites designed to make a wide variety of earth observations is discussed along with the renewed interest in the use of aircraft as platforms for similar and complementary earth resources surveys. Surveys covering the areas of forestry, agriculture, hydrology, oceanography, geology, and geography are included. Aerials surveys equipped for nonphotographic remote sensing and aircraft flights synchronized with satellite observations to provide correlated data are discussed. Photographs are shown to illustrate preliminary results from several of the test sites.
A method is developed for the statistical estimation of the number of cracks to be repaired in service as well as the repair and the maintenance costs. The present approach accounts for the statistical distribution of the initial crack size, the statistical nature of the NDI technique used for detecting the crack, and the renewal process for the crack propagation of repaired cracks. The mean and the standard deviation of the cumulative number of cracks to be repaired are computed as a function of service time. The statistics of the costs of repair and maintenance, expressed in terms of the percentage of the cost of replacement, are estimated as a function of service time. The results of the present study provide relevant information for the decision of fleet management, the estimation of life cycle cost, and procurement specifications. The present study is essential to the design and cost optimization of aircraft structures.
The determination of the geoid has been one of the prime goals of geodesy. Knowledge of geoid undulations with respect to some reference surface was needed for the determination of the figure of the earth, for the precise reduction of distance measurements to a reference ellipsoid, and for the determination of the geocentric location of points on the surface of the earth. Currently and in the future, undulation information can also be used in geophysical studies related to crustal structures and in oceanographic studies related to sea surface topography. The actual determination of global geoids has been carried out by using gravimetric data, satellite‐derived information related to the gravitational field of the earth, or a combination of the two techniques. Regional geoid determinations have been made by astrogeodetic techniques. For some applications of undulation information, undulation standard deviations of the order of ±5 m would be sufficient. Such an accuracy can be obtained by using data currently available. In the past few years, renewed interest in the geoid arose when the concept of satellite altimetry was proposed to measure the distance from the satellite to some area on the ocean surface.
Even at reduced rates of growth, the demand for electric power is expected to more than triple between now and 1995, and to triple again over the period 1995-2020. Without the development of new power sources and advanced transmission technologies, it may not be possible to supply electric energy at prices that are conductive to generalized economic welfare. Solar power is renewable and its conversion and transmission from space may be advantageous. The goal of this study is to assess the economic merit of space-based photovoltaic systems for power generation and a power relay satellite for power transmission. In this study, satellite solar power generation and transmission systems, as represented by current configurations of the Satellite Solar Station (SSPS) and the Power Relay Satellite (PRS), are compared with current and future terrestrial power generation and transmission systems to determine their technical and economic suitability for meeting power demands in the period of 1990 and beyond while meeting ever-increasing environmental and social constraints.
Two major marketing programs were initiated during 1974: (1) the unlimited search plan, and (2) the sales representative plan for northern California. The unlimited search plan was a six month program designed to offer clients multiple searches for a fixed fee. Although initial response was quite favorable, interest waned, and the plan was not renewed. Expansion and improvement of the on-line retrieval service continued. The ERIC thesaurus was added to the system. This thesaurus is an important acquisition as it gives the user greater flexibility in determining the best strategy for his search. Total terminal output time was reduced with a change to the direct access work file.
The anticipated depletion of our resources of natural gas and petroleum in a few decades has caused a search for renewable sources of fuel. Among the possibilities is the chemical conversion of waste and grown organic matter into gaseous or liquid fuels. The overall feasibility of such a system is considered from the technical, economic, and social viewpoints. Although there are a number of difficult problems to overcome, this preliminary study indicates that this option could provide between 4 and 10 percent of the U.S. energy needs. Estimated costs of fuels derived from grown organic material are appreciably higher than today's market price for fossil fuel. The cost of fuel derived from waste organics is competitive with fossil fuel prices. Economic and social reasons will prohibit the allocation of good food producing land to fuel crop production.
The increasing need to develop alternative energy sources has renewed interest in the use of wind energy for the generation of utility quality electricity. This paper discusses a program to evolve a preliminary design of a cost competitive large wind generator system. An examination of a number of technically feasible alternative wind energy configurations is reported, and the rationale used in selecting the preferred system concept is presented. In addition, preliminary results of an optimization study conducted on the preferred concept are summarized. These show that considerable latitude in the selection of the system design parameters is possible. This permits design decisions to be based on other important factors such as development risk and the suitability of common component designs for systems with different power ratings.
An overview of problems and opportunities in remote sensing of resources. The need for independence from foreign and precarious energy sources, availability of fossil fuel materials for other purposes (petrochemicals, fertilizer), environmental conservation, and new energy sources are singled out as the main topics. Phases of response include: (1) crisis, with reduced use of petroleum and tapping of on-shore and off-shore resources combined; (2) a transition phase involving a shift from petroleum to coal and oil shale; and (3) exploitation of renewable (inexhaustible and clean) energy. Opportunities for remote sensing in fuel production and energy conservation are discussed along with problems in identifying the spectral signatures of productive and unproductive regions. Mapping of water resources, waste heat, byproducts, and wastes is considered in addition to opportunities for international collaboration.
The increased search for alternative energy sources has lead to renewed interest and studies of large wind-driven generators. This paper presents the results and considerations of such an investigation. The paper emphasizes the concept selection of wind-driven generators, system optimization, control system design, safety aspects, economic viability on electric utility systems and potential electric system interfacing problems.
A reliability analysis of structures subjected to random service loads and periodic proof tests treats gust loads and maneuver loads as random processes. Crack initiation, crack propagation, and strength degradation are treated as the fatigue process. The time to fatigue crack initiation and ultimate strength are random variables. Residual strength decreases during crack propagation, so that failure rate increases with time. When a structure fails under periodic proof testing, a new structure is built and proof-tested. The probability of structural failure in service is derived from treatment of all the random variables, strength degradations, service loads, proof tests, and the renewal of failed structures. Some numerical examples are worked out.