4,329 research outputs found

    Analytical and test equipment: A compilation

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    A compilation is presented of innovations in testing and measuring technology for both the laboratory and industry. Topics discussed include spectrometers, radiometers, and descriptions of analytical and test equipment in several areas including thermodynamics, fluid flow, electronics, and materials testing

    Investigation of reliability attributes and accelerated stress factors on terrestrial solar cells

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    Major effort during this reporting period was devoted to two tasks: improvement of the electrical measurement instrumentation through the design and construction of a microcomputer controlled short interval tester, and better understanding of second quadrant behavior by developing a mathematical model relating cell temperature to electrical characteristics. In addition, some preliminary work is reported on an investigation into color changes observed after stressing

    NASA Tech Briefs Index, 1977, volume 2, numbers 1-4

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    Announcements of new technology derived from the research and development activities of NASA are presented. Abstracts, and indexes for subject, personal author, originating center, and Tech Brief number are presented for 1977

    Index to NASA Tech Briefs, 1975

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    This index contains abstracts and four indexes--subject, personal author, originating Center, and Tech Brief number--for 1975 Tech Briefs

    Index to nasa tech briefs, issue number 2

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    Annotated bibliography on technological innovations in NASA space program

    The NASA SBIR product catalog

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    The purpose of this catalog is to assist small business firms in making the community aware of products emerging from their efforts in the Small Business Innovation Research (SBIR) program. It contains descriptions of some products that have advanced into Phase 3 and others that are identified as prospective products. Both lists of products in this catalog are based on information supplied by NASA SBIR contractors in responding to an invitation to be represented in this document. Generally, all products suggested by the small firms were included in order to meet the goals of information exchange for SBIR results. Of the 444 SBIR contractors NASA queried, 137 provided information on 219 products. The catalog presents the product information in the technology areas listed in the table of contents. Within each area, the products are listed in alphabetical order by product name and are given identifying numbers. Also included is an alphabetical listing of the companies that have products described. This listing cross-references the product list and provides information on the business activity of each firm. In addition, there are three indexes: one a list of firms by states, one that lists the products according to NASA Centers that managed the SBIR projects, and one that lists the products by the relevant Technical Topics utilized in NASA's annual program solicitation under which each SBIR project was selected

    Investigation of accelerated stress factors and failure/degradation mechanisms in terrestrial solar cells

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    Research on the reliability of terrestrial solar cells was performed to identify failure/degradation modes affecting solar cells and to relate these to basic physical, chemical, and metallurgical phenomena. Particular concerns addressed were the reliability attributes of individual single crystalline, polycrystalline, and amorphous thin film silicon cells. Results of subjecting different types of crystalline cells to the Clemson accelerated test schedule are given. Preliminary step stress results on one type of thin film amorphous silicon (a:Si) cell indicated that extraneous degradation modes were introduced above 140 C. Also described is development of measurement procedures which are applicable to the reliability testing of a:Si solar cells as well as an approach to achieving the necessary repeatability of fabricating a simulated a:Si reference cell from crystalline silicon photodiodes

    Index to 1983 NASA Tech Briefs, volume 8, numbers 1-4

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    Short announcements of new technology derived from the R&D activities of NASA are presented. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This index for 1983 Tech Briefs contains abstracts and four indexes: subject, personal author, originating center, and Tech Brief Number. The following areas are covered: electronic components and circuits, electronic systems, physical sciences, materials, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

    Hybrid Energy Storage Systems for UAV Applications

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    Energy storage constraints limit the range and endurance of electric based unmanned aerial vehicles (UAVs). Solving the energy storage problem allows the adoption of UAVs on a much wider scale. A solution to the problem would ideally retain the significant performance and efficiency benefits of the electric based propulsion system. The contents of this study focused on solving the energy storage problem through research, experiment, and simulation based testing of the application of hybrid energy storage systems (HESS) to existing UAV designs. A review of literature was done exploring existing and future applications of electric based aircraft propulsion systems. Research was conducted on current energy storage technology limitations and potential hybrid energy storage design solutions. The solution allows bridging the gap to full adoption of electric propulsion. After extensive research, a passively controlled hybrid battery and supercapacitor configuration was chosen for experimental and simulation based evaluations. The experiment and simulation tested for key battery performance improvements using the HESS and its applicability to UAV designs. Results showed a significant reduction to the peak amperage and peak temperature of the battery under identical load profiles. The experimentally tested passive HESS did not show a reduction in energy consumption, but the active HESS simulation results did. The simulation results showed a theoretical gain of 8.8% for state of charge (SOC) for the battery. Equating the SOC to range improvement, a 10% increase in range was possible for the UAV tested

    FY87 scientific and technical reports, articles, papers, and presentations

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    The document presents formal NASA technical reports, papers published in technical journals, and presentations by MSFC personnel in FY87. It also includes papers of MSFC contractors. After being announced in STAR, all of the NASA series reports may be obtained from the National Technical Information Service, 5285 Port Royal Road, Springfield, Va. 22161. The information in this report may be of value to the scientific and engineering community in determining what information has been published and what is available
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