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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 847 records · Page 47
All sourcesNASA NTRSDOE OSTI
NASA NTRS1982

Metals processing

The metals processing effort is directed towards improvement of performance and usefulness of materials through modification and control of shape and internal structure. Interaction of reactive gases, introduced into a plasma arc, with iron alloys were analyzed. The technology of magnesium production was assessed. The study of fast fluidized bed reactors is continued. Aspects of separation processes are being investigated. The development of high field superconducting composites for use in large magnetic fusion devices is also discussed. Processing, structure, and property relationships of superconducting materials and the substitution of precious metals in standard electrical contact and connector applications are tested. The influence of processing procedures on the structure of zircaloy and nickel base alloys with a goal of improving mechanical properties and performance is investigated. Investigation of the potential of metal insulator semiconductor junctions as photovoltaic devices is reported.

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NASA NTRS1981

The GA sulfur-iodine water-splitting process - A status report

The development of a sulfur-iodine thermal water splitting cycle is described. The process features a 50% thermal efficiency, plus all liquid and gas handling. Basic chemical investigations comprised the development of multitemperature and multistage sulfuric acid boost reactors, defining the phase behavior of the HI/I2/H2O/H3PO4 mixtures, and development of a decomposition process for hydrogen iodide in the liquid phase. Initial process engineering studies have led to a 47% efficiency, improvements of 2% projected, followed by coupling high-temperature solar concentrators to the splitting processes to reduce power requirements. Conceptual flowsheets developed from bench models are provided; materials investigations have concentrated on candidates which can withstand corrosive mixtures at temperatures up to 400 deg K, with Hastelloy C-276 exhibiting the best properties for containment and heat exchange to I2.

Besenbruch, G. E.↗
NASA NTRS1981

New technologies for solar energy silicon - Cost analysis of dichlorosilane process

A reduction in the cost of silicon for solar cells is an important objective in a project concerned with the reduction of the cost of electricity produced with solar cells. The cost goal for the silicon material is about $14 per kg (1980 dollars). The process which is currently employed to produce semiconductor grade silicon from trichlorosilane is not suited for meeting this cost goal. Other processes for producing silicon are, therefore, being investigated. A description is presented of results obtained for the DCS process which involves the production of dichlorosilane as a silicon source material for solar energy silicon. Major benefits of dichlorosilane as a silicon source material include faster reaction rates for chemical vapor deposition of silicon. The DCS process involves the reaction 2SiHCl3 yields reversibly SiH2Cl2 + SiCl4. The results of a cost analysis indicate a total product cost without profit of $1.29/kg of SiH2Cl2.

Yaws, C. L.↗
NASA NTRS1981

Development of large area, low-cost, solar cell processing sequence

A cost effective process based on state-of-the-art technology has been developed for the production of large-area (55 sq cm and larger) solar cells. The process is capable of providing silicon and polysilicon cell efficiencies in excess of 10% at an overall cost of 12 c/watt in 1980 dollars. The process provides large throughputs and is suitable for complete automation with high yields. Various stages of the process development are discussed.

Chitre, S.↗
NASA NTRS1982

Preflight and postflight processing of Spacelab missions at KSC

The Spacelab program is discussed in the context of the preparation of assembly, test, and processing facilities at the Kennedy Space Center (KSC). The management of the program within NASA is reviewed, along with flight tests of experimental packages, the first Spacelab mission, payload mission management, Spacelab processing responsibilities at the KSC, Space Shuttle processing and launch, Spacelab deintegration, OSS-1 management functions, and the OSS-1 processing flow at the KSC. The four levels of payload integration and checkout on a Spacelab are described, and testing at the four levels is briefly examined.

Neilon, J. J.↗
NASA NTRS1982

Computer processed LANDSAT data

Background information and exercises are provided to: (1) establish or expand understanding of the concepts, methods, and terminology of computer processing of image producing data; (2) develop insight into the advantages of computer based image processing compared with the photointerpretation approach for processing, classifying, interpreting, and applying remote sensing data; (3) foster a broad perspective on the principal of the main techniques for image enhancement, pattern recognition, and thematic classification; (4) appreciate the pros and cons of batch and interactive modes of image analysis; (5) examine and evaluate some specific computer generated products for subscenes in Pennsylvania and New Jersey; and (6) interrelate these particular examples of output with more theoretical explanations of computer processing strategies and procedures.

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NASA NTRS1982

Appendix B: Principles of computer processing of LANDSAT data

Computer processing facilitates extraction of information from every pixel by executing a variety of functional operations, called processed algorithms, in general or specialized routines. The best results are obtained when data from more than one multispectral band are used together. Multivariate tatistical analysis, computer tape characteristics, processing modes, and a choice of systems (batch or interactive) are discussed. The major operations in computer processing elaborated include: preprocessing, enhancement, effects of rationing, and classification. Techniques for multisource data correlation are considered with emphasis on geobased systems.

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NASA NTRS1980

Extraterrestrial materials processing and construction

Three different chemical processing schemes were identified for separating lunar soils into the major oxides and elements. Feedstock production for space industry; an HF acid leach process; electrorefining processes for lunar free metal and metal derived from chemical processing of lunar soils; production and use of silanes and spectrally selective materials; glass, ceramics, and electrochemistry workshops; and an econometric model of bootstrapping space industry are discussed.

Criswell, D. R.↗
NASA NTRS1980

Future integrated design process

The design process is one of the sources used to produce requirements for a computer system to integrate and manage product design data, program management information, and technical computation and engineering data management activities of the aerospace design process. Design activities were grouped chronologically and explored for activity type, activity interface, data quantity, and data flow. The work was based on analysis of the design process of several typical aerospace products, including both conventional and supersonic airplanes and a hydrofoil design. Activities examined included research, preliminary design, detail design, manufacturing interface, product verification, and product support. The design process was then described in an IPAD environment--the future.

Meyer, D. D.↗
NASA NTRS1980

Case study: Lockheed-Georgia Company integrated design process

A case study of the development of an Integrated Design Process is presented. The approach taken in preparing for the development of an integrated design process includes some of the IPAD approaches such as developing a Design Process Model, cataloging Technical Program Elements (TPE's), and examining data characteristics and interfaces between contiguous TPE's. The implementation plan is based on an incremental development of capabilities over a period of time with each step directed toward, and consistent with, the final architecture of a total integrated system. Because of time schedules and different computer hardware, this system will not be the same as the final IPAD release; however, many IPAD concepts will no doubt prove applicable as the best approach. Full advantage will be taken of the IPAD development experience. A scenario that could be typical for many companies, even outside the aerospace industry, in developing an integrated design process for an IPAD-type environment is represented.

Waldrop, C. T.↗
NASA NTRS1983

ECUT: Energy Conversion and Utilization Technologies program biocatalysis research activity. Potential membrane applications to biocatalyzed processes: Assessment of concentration polarization and membrane fouling

Separation and purification of the products of biocatalyzed fermentation processes, such as ethanol or butanol, consumes most of the process energy required. Since membrane systems require substantially less energy for separation than most alternatives (e.g., distillation) they have been suggested for separation or concentration of fermentation products. This report is a review of the effects of concentration polarization and membrane fouling for the principal membrane processes: microfiltration, ultrafiltration, reverse osmosis, and electrodialysis including a discussion of potential problems relevant to separation of fermentation products. It was concluded that advanced membrane systems may result in significantly decreased energy consumption. However, because of the need to separate large amounts of water from much smaller amounts of product that may be more volatile than wate, it is not clear that membrane separations will necessarily be more efficient than alternative processes.

Ingham, J. D.↗
NASA NTRS1983

Evaluation of the ion implantation process for production of solar cells from silicon sheet materials

The objective of this program is the investigation and evaluation of the capabilities of the ion implantation process for the production of photovoltaic cells from a variety of present-day, state-of-the-art, low-cost silicon sheet materials. Task 1 of the program concerns application of ion implantation and furnace annealing to fabrication of cells made from dendritic web silicon. Task 2 comprises the application of ion implantation and pulsed electron beam annealing (PEBA) to cells made from SEMIX, SILSO, heat-exchanger-method (HEM), edge-defined film-fed growth (EFG) and Czochralski (CZ) silicon. The goals of Task 1 comprise an investigation of implantation and anneal processes applied to dendritic web. A further goal is the evaluation of surface passivation and back surface reflector formation. In this way, processes yielding the very highest efficiency can be evaluated. Task 2 seeks to evaluate the use of PEBA for various sheet materials. A comparison of PEBA to thermal annealing will be made for a variety of ion implantation processes.

Spitzer, M. B.↗
NASA NTRS1981

A model for simulation and processing of radar images

A model for recording, processing, presentation, and analysis of radar images in digital form is presented. The observed image is represented as having two random components, one which models the variation due to the coherent addition of electromagnetic energy scattered from different objects in the illuminated areas. This component is referred to as fading. The other component is a representation of the terrain variation which can be described as the actual signal which the radar is attempting to measure. The combination of these two components provides a description of radar images as being the output of a linear space-variant filter operating on the product of the fading and terrain random processes. In addition, the model is applied to a digital image processing problem using the design and implementation of enhancement scene. Finally, parallel approaches are being employed as possible means of solving other processing problems such as SAR image map-matching, data compression, and pattern recognition.

Stiles, J. A.↗
NASA NTRS1981

Technology and future ground processing systems

Land-observing satellites with multiple thematic mappers will produce data at rates of 100 to 300 Mbps. When coupled with a high daily scene production rate, these rates will require new approaches to ground processing. Consideration is given here to future downlink rates and data volumes, and requirements peculiar to the future user community are discussed. The advanced technologies required to attain an operational system in the years 1985-1990 are considered, together with advances foreseen in communications, mass storage, bulk memories, and data processing. Using advanced devices, a centralized data processing system capable of handling the 100 Mbps data rate is described. New approaches, among them a parallel pipelined calibration front-end, real-time browse image production, a high bandwidth optical disk archive, regional image broadcast and massively parallel product production, are considered. A distributed system capable of handling the 300 Mbps data rate is then described. Designs for a hub system and a regional processing center are presented.

Wood, B. J.↗
NASA NTRS1981

Bit error rate performance of Image Processing Facility high density tape recorders

The Image Processing Facility at the NASA/Goddard Space Flight Center uses High Density Tape Recorders (HDTR's) to transfer high volume image data and ancillary information from one system to another. For ancillary information, it is required that very low bit error rates (BER's) accompany the transfers. The facility processes about 10 to the 11th bits of image data per day from many sensors, involving 15 independent processing systems requiring the use of HDTR's. When acquired, the 16 HDTR's offered state-of-the-art performance of 1 x 10 to the -6th BER as specified. The BER requirement was later upgraded in two steps: (1) incorporating data randomizing circuitry to yield a BER of 2 x 10 to the -7th and (2) further modifying to include a bit error correction capability to attain a BER of 2 x 10 to the -9th. The total improvement factor was 500 to 1. Attention is given here to the background, technical approach, and final results of these modifications. Also discussed are the format of the data recorded by the HDTR, the magnetic tape format, the magnetic tape dropout characteristics as experienced in the Image Processing Facility, the head life history, and the reliability of the HDTR's.

Heffner, P.↗
NASA NTRS1982

Celion/Larc-160 graphite/polyimide composite processing techniques and properties

Weight savings in the range from 25 to 35 percent could be achieved on Space Shuttle orbiter components and the thermal protection system (TPS) by employing a suitable graphite/polyimide (Gr/Pi) composite material system as a substitute for the baseline aluminum structural material. Predicted weight savings are based on the superior strength and stiffness-to-density ratios of Gr/Pi composite material over metallic counterparts. Specific strength and stiffness properties of Celion/Larc-160 composite laminates are compared with aluminum and titanium alloys. Aspects of materials and processes development are discussed, taking into account Celion/Larc-160 composite cure cycle and tooling evolution, complex shaped component process development, mechanical and physical properties testing and results, and structural element design fabrication, testing, and results. Attention is given to a demonstration of materials and processing technology, and a Celion/Larc-160 materials and processes summary is presented.

Jones, J. S.↗
NASA NTRS1982

Glass processing in a microgravity environment

The basic techniques used in the processing of glasses and crystalline ceramics under terrestrial conditions are briefly reviewed, and the features of the space environment relevant to the processing of glasses are examined. These include reduced gravitational forces, a vacuum of essentially unlimited pumping capacity, unique radiation conditions, and the unlimited dimensions of space. Of these factors, particular attention is given to reduced gravitational forces, and the advantages of containerless processing are discussed. Finally, current programs concerned with glass processing in space are reviewed along with additional areas which merit investigation.

Uhlmann, D. R.↗
NASA NTRS1982

A comparative study of real-time spaceborne synthetic aperture radar processing techniques

A review of various spaceborne synthetic aperture radar (SAR) processing algorithms and their associated real-time SAR processor architectures is given in this paper. The processing complexity for each real-time SAR processor is presented next. A complexity comparison is then given based on the Seasat SAR parameters. It is shown that the frequency/time domain hybrid fast correlation and the two-stage fast Fourier transform (FET) approaches are the two most cost-effective choices for real-time spaceborne SAR processing. Finally, a discussion on future development trends in real-time spaceborne SAR processing is given.

Liu, K. Y.↗