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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
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Land use classification in Bolivia

The Bolivian LANDSAT Program is an integrated, multidisciplinary project designed to provide thematic analysis of LANDSAT, Skylab, and other remotely sensed data for natural resource management and development in Bolivia, is discussed. Among the first requirements in the program is the development of a legend, and appropriate methodologies, for the analysis and classification of present land use based on landscape cover. The land use legend for Bolivia consists of approximately 80 categories in a hierarchical organization which may be collapsed for generalization, or expanded for greater detail. The categories, and their definitions, provide for both a graphic and textual description of the complex and diverse landscapes found in Bolivia, and are designed for analysis from LANDSAT and other remotely sensed data at scales of 1:1,000,000 and 1:250,000. Procedures and example products developed are described and illustrated, for the systematic analysis and mapping of present land use for all of Bolivia.

Brockmann, C. E.↗
NASA NTRS1976

An investigation of potential applications of OP-SAPS: Operational sampled analog processors

The impact of charge-coupled device (CCD) processors on future instrumentation was investigated. The CCD devices studied process sampled analog data and are referred to as OP-SAPS - operational sampled analog processors. Preliminary studies into various architectural configurations for systems composed of OP-SAPS show that they have potential in such diverse applications as pattern recognition and automatic control. It appears probable that OP-SAPS may be used to construct computing structures which can serve as special peripherals to large-scale computer complexes used in real time flight simulation. The research was limited to the following benchmark programs: (1) face recognition, (2) voice command and control, (3) terrain classification, and (4) terrain identification. A small amount of effort was spent on examining a method by which OP-SAPS may be used to decrease the limiting ground sampling distance encountered in remote sensing from satellites.

Parrish, E. A.↗
NASA NTRS1975

Plasma Sterilization Technology for Spacecraft Applications

The application of plasma gas technology to sterilization and decontamination of spacecraft components is considered. Areas investigated include: effective sterilizing ranges of four separate gases; lethal constituents of a plasma environment; effectiveness of plasma against a diverse group of microorganisms; penetrating efficiency of plasmas for sterilization; and compatibility of spacecraft materials with plasma environments. Results demonstrated that plasma gas, specifically helium plasma, is a highly effective sterilant and is compatible with spacecraft materials.

Fraser, S. J.↗
NASA NTRS1976

ATS-6 millimeter wavelength propagation experiment

The Ohio State University participation in the ATS-6 Millimeter Wavelength Propagation Experiment is summarized. Attenuation was measured simultaneously at 20 and 30 GHz on earth space propagation paths to two ground terminals located at Columbus, Ohio. In addition, 20 and 30 GHz radiometric temperatures were measured along the same propagation paths; and the 20 GHz radiometric temperature was also measured at a third ground terminal. The results of these measurements are presented, and diversity gains for the four pairs of propagation paths are discussed. The scintillation characteristics of the received signals are also presented.

Hodge, D. B.↗
NASA NTRS1976

Twenty and thirty GHz millimeter wave experiments with the ATS-6 satellite

Studies at 11 locations in the continental United States were directed at an evaluation of rain attenuation effects, scintillations, depolarization, site diversity, coherence bandwidth, and analog and digital communications techniques using the Applications Technology Satellite-6(ATS-6). In addition to direct measurements on the 20- and 30-GHz links, methods of attenuation prediction with radars, rain gages, and radiometers were developed and compared with the directly measured attenuation. Initial data results of the ATS-6 millimeter wave experiment were presented. The first section describes the experiment objectives, flight hardware, and modes of operation. The remaining six sections present papers prepared by the major participating organizations in the experiment. The papers present a comprehensive summary of the significant results of the initial 11 months of ATS-6 experiment measurements and related radiometric, radar, and radio-meteorology studies.

Ippolito, L. J.↗
NASA NTRS1975

Application of remote sensing technology to land evaluation, planning utilization of land resources, and assessment of wildlife areas in eastern South Dakota

A soils map for land evaluation in Potter County (Eastern South Dakota) was developed to demonstrate the use of remote sensing technology in the area of diverse parent materials and topography. General land use and soils maps have also been developed for land planning LANDSAT, RB-57 imagery, and USGS photographs are being evaluated for making soils and land use maps. LANDSAT fulfilled the requirements for general land use and a general soils map. RB-57 imagery supplemented by large scale black and white stereo coverage was required to provide the detail needed for the final soils map for land evaluation. Color infrared prints excelled black and white coverage for this soil mapping effort. An identification and classification key for wetland types in the Lake Dakota Plain was developed for June 1975 using color infrared imagery. Wetland types in the region are now being mapped via remote sensing techniques to provide a current inventory for development of mitigation measures.

Source record↗
NASA NTRS1976

The rationale and design features for the 40 by 80/80 by 120 foot wind tunnel

A substantial increase in the test capability of full scale wind tunnels is considered. In order to determine the most cost effective means for providing this desired increase in test capability, a series of design studies were conducted of various new facilities as well as of major modifications to the existing 40- by 80-foot wind tunnel. The most effective trade between test capability and facility cost was provided by repowering the existing 40 by 80 foot wind tunnel to increase the maximum speed from 200 knots to 300 knots and by the addition of a new 80- by 120-foot test section having a 110 knot maximum speed. The design of the facility is described with special emphasis on the unique features, such as the drive system which absorbs nearly four times the power without an increase in noise, and the large flow diversion devices required to interface the two test sections to a single drive.

Mort, K. W.↗
NASA NTRS1976

Program to design, fabricate, test, and deliver a thermal control-mixing control device for the George C. Marshall Space Flight Center

The development and testing of a temperature sensor and pulse duration modulation (PDM) diverter valve for a thermal control-mixing control device are described. The temperature sensor selected for use uses a fluidic pin amplifier in conjunction with an expansion device. This device can sense changes of less than 0.25 F with greater than 15:1 signal to noise ratio when operating with a typical Freon pump supplied pressure. The pressure sensitivity of the sensor is approximately 0.0019 F/kPa. The valve which was selected was tested and performed with 100% flow diversion. In addition, the valve operates with a flow efficiency of at least 95%, with the possibility of attaining 100% if the vent flow of the PDM can be channeled through the last stage of the diverter valve. A temperature sensor which utilized an orifice bridge circuit and proportional-vortex combination mixing valve were also evaluated, but the concepts were rejected due to various problems.

Thurston, T. S.↗
NASA NTRS1975

Dynamics of turbidity plumes in Lake Ontario

The author has identified the following significant results. Large turbidity features along the 275 km south shore of Lake Ontario were analyzed using LANDSAT-1 images. The Niagara River plume, ranging from 30 to 500 sq km in area is, by far, the largest turbidity feature in the lake. Based on image tonal comparisons, turbidity in the Welland Canal is usually higher than that in any other water course discharging into the lake during the shipping season. Less turbid water enters the lake from the Port Dalhousie diversion channel and the Genesee River. Relatively clear water resulting from the deposition of suspended matter in numerous upstream lakes is discharged by the Niagara and Oswego Rivers. Plume analysis corroborates the presence of a prevailing eastward flowing longshore current along the entire south shore. Plumes resulting from beach erosion were detected in the images. Extensive areas of the south shore are subject to erosion but the most severely affected beaches are situated between Fifty Mile Point, Ontario and Thirty Mile Point, New York along the Rochester embayment, and between Sodus Bay and Nine Mile Point.

Pluhowski, E. J.↗
NASA NTRS1975

Theoretical and experimental prerequisites of exobiology

Exobiology and the origin of life: The Inseparable Connection The world we live in is constantly changing through a process of evolutionary development that is gradual, and which leads to emergence of ever newer, more complex, more diverse, and richly differentiated forms of reality. This process may not occur simultaneously and identically everywhere, but in different ways at different rates in various places in the universe and on various objects in the celestial world. Thus, evolution must not be diagramed as a single direct line, but rather as a cluster of various paths, whose separate branches may lead to very complex and complete forms of organization and movement of matter. Nothing is known about many of these forms, and in numerous instances, their existence is not even suspected. Any one form should not be considered prematurely as a special category of life, only because of its complexity or perfection. Life is far from a result of all the numerous branches in the development of matter; its specific qualities and ways of emerging and improving are inherent. Only a single example of life, terrestrial life, is known at present, from which judgments must proceed of other possible forms of biological organization. The Earth and the events which originated on it must, to a great extent, serve as a model for broader judgments of life in the universe.

A. I. Oparin↗
NASA NTRS1976

Forty and 80 GHz technology assessment and forecast including executive summary

The results of a survey to determine current demand and to forecast growth in demand for use of the 40 and 80 GHz bands during the 1980-2000 time period are given. The current state-of-the-art is presented, as well as the technology requirements of current and projected services. Potential developments were identified, and a forecast is made. The impacts of atmospheric attenuation in the 40 and 80 GHz bands were estimated for both with and without diversity. Three services for the 1980-2000 time period -- interactive television, high quality three stereo pair audio, and 30 MB data -- are given with system requirements and up and down-link calculations.

Mazur, D. G.↗
NASA NTRS1976

Irradiate-anneal screening of total dose effects in semiconductor devices

An extensive investigation of irradiate-anneal (IRAN) screening against total dose radiation effects was carried out as part of a program to harden the Mariner Jupiter/Saturn 1977 (MJS'77) spacecraft to survive the Jupiter radiation belts. The method consists of irradiating semiconductor devices with Cobalt-60 to a suitable total dose under representative bias conditions and of separating the parts in the undesired tail of the distribution from the bulk of the parts by means of a predetermined acceptance limit. The acceptable devices are then restored close to their preirradiation condition by annealing them at an elevated temperature. IRAN was used when lot screen methods were impracticable due to lack of time, and when members of a lot showed a diversity of radiation response. The feasibility of the technique was determined by testing of a number of types of linear bipolar integrated circuits, analog switches, n-channel JFETS and bipolar transistors. Based on the results of these experiments a number of device types were selected for IRAN of flight parts in the MJS'77 spacecraft systems. The part types, screening doses, acceptance criteria, number of parts tested and rejected as well as the program steps are detailed.

Stanley, A. G.↗
NASA NTRS1975

Use of remote sensing in agriculture

The remote sensing studies of (a) cultivated peanut areas in Southeastern Virginia; (b) studies at the Virginia Truck and Ornamentals Research Station near Painter, Virginia, the Eastern Virginia Research Station near Warsaw, Virginia, the Tidewater Research and Continuing Education Center near Suffolk, Virginia, and the Southern Piedmont Research and Continuing Education Center Blackstone, Virginia; and (c) land use classification studies at Virginia Beach, Virginia are presented. The practical feasibility of using false color infrared imagery to detect and determine the areal extent of peanut disease infestation of Cylindrocladium black rot and Sclerotinia blight is demonstrated. These diseases pose a severe hazard to this major agricultural food commodity. The value of remote sensing technology in terrain analyses and land use classification of diverse land areas is also investigated. Continued refinement of spectral signatures of major agronomic crops and documentation of pertinent environmental variables have provided a data base for the generation of an agricultural-environmental prediction model.

Pettry, D. E.↗
NASA NTRS1976

Prediction of passenger ride quality in a multifactor environment

A model being developed, permits the understanding and prediction of passenger discomfort in a multifactor environment with particular emphasis upon combined noise and vibration. The model has general applicability to diverse transportation systems and provides a means of developing ride quality design criteria as well as a diagnostic tool for identifying the vibration and/or noise stimuli causing discomfort. Presented are: (1) a review of the basic theoretical and mathematical computations associated with the model, (2) a discussion of methodological and criteria investigations for both the vertical and roll axes of vibration, (3) a description of within-axis masking of discomfort responses for the vertical axis, thereby allowing prediction of the total discomfort due to any random vertical vibration, (4) a discussion of initial data on between-axis masking, and (5) discussion of a study directed towards extension of the vibration model to the more general case of predicting ride quality in the combined noise and vibration environments.

Dempsey, T. K.↗
NASA NTRS1976

Rendezvous radar modification and evaluation

The purpose of this effort was to continue the implementation and evaluation of the changes necessary to add the non-cooperative mode capability with frequency diversity and a doppler filter bank to the Apollo Rendezvous Radar while retaining the cooperative mode capability.

Source record↗
NASA NTRS1976

The project scientist's role in scientific spacecraft project management

The project scientists is in a position which rates very high in terms of behavioral study recommendations. His influence over objectives is generally considered to be important. He is highly autonomous in a moderately coordinated environment. He has diverse managerial and technical functions and the performance of these functions require him to grow beyond his role as an experimenter. However, the position within the line organization for those interviewed is also very stimulating, rating almost as high by the same criteria. The role of project scientist may not be the dominant means of professional growth for the experienced scientific investigators. The influence which the project scientist exerts on the project and the stimulation of that position for him are determined largely by his position outside the defined project scientist role. The role of the project scientist is changing because the environment of those who become project scientists is changing.

Eller, E. L.↗
NASA NTRS1975

Availability of a communications satellite - Requirement and feasibility

An estimated 45 communications satellites will be in geostationary orbit in the 1980s. Based on past history, half of the subsystem failures will be due to design failures. Methods now used to achieve present availabilities are summarized in this paper. To increase the availability of a single satellite to 99.99%, new techniques are needed; several possibilities are suggested herein. New developments, including nickel-hydrogen batteries, magnetic bearings, and solid-state amplifiers, are possible solutions to long standing problem areas in communications satellites. Launching a satellite two or three years before the system is needed is one way to reduce design failures in subsequent satellites. Diversity of manufacture can be used to obtain the maximum advantage from redundant elements. Finally, unmanned module exchange at geostationary orbit has been shown to be technically feasible.

Gordon, G. D.↗
NASA NTRS1975

System consideration, design approach and test of a low gain spherical coverage antenna for large space vehicles

A fixed beam array antenna approach is proposed to meet the omnidirectional receiving and transmitting requirements of LST (Large Space Telescope). The proposed method uses an antenna of known performance and scales the size and frequency to conform with the LST 1/5-th scale model. The simplification that the approach provides over switching antenna elements on board the LST or switching from the ground by frequency diversity makes it worthy of consideration against the factors of performance, cost, reliability, and operations complexity. For LST applications, the system capabilities, requirements, and margins are summarized. The areas to be covered by further investigations into the proposed LST antenna are noted.

Ferguson, R. E.↗