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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 73 records · Page 4

Book Out! An Inventory Story

The NASA Glenn Library is a science and engineering research library providing the most current books, journals, CD-ROM's and documents to support the study of aeronautics, space propulsion and power, communications technology, materials and structures and microgravity science. The GRC technical library also supports the research and development efforts of all scientists and engineers on site via full text electronic files, literature searching, technical reports, etc. As an intern in the NASA Glenn Library, I attempt to support these objectives through efficiently and effectively fulfilling the assignment that was given to me. The assignment that was relegated to me was to catalog National Advisory Committee for Aeronautics, NASA Technical Documents into NASA Galaxie. This process consists of holdings being added to existing Galaxie records, upgrades and editing done to the bibliographic records when needed, adding URL's into Galaxie when they were missing from the record. NASA ASAP and Digidoc was used to locate URL's of PDF's that were not in Galaxie. A spreadsheet of documents with no URL's were maintained. Also, a subject channel of web, fill-text, paid and free, journal and other subject specific pages were developed and expanded fiom current content of intranet pages. To expand upon the second half of my assignment, I was given the project of taking inventory of the library s book collection. I kept record of the books that were not accounted for on a master list I was given to work fiom and submitted them for correction and addition. I also made sure the books were placed in the appropriate order and made corrections to any discrepancies that existed between the master list and what was on the shelf. Upon completion of this assignment, I will have verified that 21,113 books were in the correct location, order and have the correct corresponding serial number and barcode. In conclusion, as of this date I have input around 750 documents into NASA Galaxie, inputting about half of the NASA Technical Documents into the system. The rest of my tenure in this program will consist of finishing the other half of the reports. In regard to the second assignment, I still have about three-quarters of the collection to record and correct.

Panait, Claudia M.↗

Proposal Drafted for Allocating Space-to-Space Frequencies in the GPS Spectrum Bands

Radionavigation Satellite Service (RNSS) systems such as the U.S. Global Positioning System (GPS) and the Russian Global Navigation Satellite System (GLONASS) are primarily being used today in the space-to-Earth direction (i.e., from GPS satellite to Earth user) for a broad range of applications such as geological surveying; aircraft, automobile, and maritime navigation; hiking and mountain climbing; and precision farming and mining. However, these navigation systems are being used increasingly in space. Beginning with the launch of the TOPEX/Poseidon remote-sensing mission in 1992, over 90 GPS receivers have flown onboard spacecraft for such applications as real-time spacecraft navigation, three-axis attitude control, precise time synchronization, precision orbit determination, and atmospheric profiling. In addition to use onboard many science spacecraft, GPS has been used or is planned to be used onboard the shuttles, the International Space Station, the International Space Station Emergency Crew Return Vehicle, and many commercial satellite systems such as Orbcomm, Globalstar, and Teledesic. From a frequency spectrum standpoint, however, one important difference between the space and terrestrial uses of GPS is that it is being used in space with no interference protection. This is because there is no frequency allocation for the space-to-space use of GPS (i.e., from GPS satellite to user spacecraft) in the International Telecommunications Union (ITU) regulatory table of frequency allocations. If another space-based or groundbased radio system interferes with a spaceborne GPS user, the spaceborne user presently has no recourse other than to accept the interference. Consequently, for the past year and a half, the NASA Glenn Research Center at Lewis Field and other Government agencies have been working within ITU toward obtaining a GPS space-to-space allocation at the next World Radio Conference in the year 2000 (WRC 2000). Numerous interference studies have been conducted in support of a primary space-tospace allocation in the 1215- to 1260-MHz and 1559- to 1610-MHz RNSS bands. Most of these studies and analyses were performed by Glenn and submitted as U.S. input documents to the international Working Party 8D meetings in Geneva, Switzerland. In the structure of the ITU, Working Party 8D is responsible for frequency spectrum issues in the RNSS and the mobile satellite service (MSS). The full texts of the studies are available from the ITU web site under Working Party 8D contributions. Note that because spaceborne RNSS receivers operate in a receive-only mode with navigation signals already being broadcast toward the Earth, the addition of a space-tospace allocation will not result in interference with other systems. A space-based RNSS receiver, however, could experience interference from systems of other services, including intraservice interference from other RNSS systems. The interference scenarios examined in the studies can be inferred from the following frequency allocation charts. In these charts, services labeled in all capital letters (e.g., "ARNS") have primary status, whereas those labeled with sentence-style capitalization (e.g., "Amateur radio") have secondary status (i.e., a service with secondary status cannot claim interference protection from or cause harmful interference to a service with primary status). Charts showing the ITU frequency allocations in the 960 to 1350 MHZ range and the 1525-1660 MHZ range are discussed and presented.

Spence, Rodney L.↗

A document describing shuttle considerations for the design of large space structures

A Shuttle user guide document to aid designers and analysis associated with large space structures projects is described. The format and contents are a compromise designed to satisfy the needs of several levels of users. Special features include checklists and references to source documents as a convenience to very knowledgeable readers. In addition, general, introductory and explanatory text, and art work are included for the reader less familiar with shuttle systems. Also, there are a subject index, glossary, list of acronyms, and many cross references. Throughout the document, there are suggested implications or references to the importance of the included orbiter interfaces material as it pertains to designing and planning large space structures projects. The content of the document is outlined. Shuttle payload accommodations and constraints, connections for orbiter construction fixtures, packaging, and construction space eometry are addressed.

Roebuck, J. A., Jr.↗

Jupiter: Studies of the interior, atmosphere, magnetosphere and satellites; Proceedings of the Colloquium, Tucson, Ariz., May 19-21, 1975

This volume is a comprehensive technical text covering all scientific aspects of Jupiter's interior, atmosphere, magnetosphere, and satellites. The chapters deal with such general subjects as the origin and interior structure of Jupiter, the planet's atmosphere and ionosphere, as well as its magnetosphere, radiation belts, and satellites. Specific topics include a review of theories on the origin and structure of Jupiter and its satellites, interior models of Jupiter, the planet's gravity field, its thermal and atmospheric structure, model ionospheres, chemistry and spectroscopy of the atmosphere, the IR spectrum of the planet, and the meteorology of the atmosphere. Other chapters discuss radio observations of Jupiter, the dynamics of the Jovian magnetosphere, structural and thermal models of the icy Galilean satellites and Io's atmosphere and optical emissions. Results are evaluated for the IR radiometer experiment on Pioneers 10 and 11, radio occultation measurements from the Pioneer probes, Pioneer 10 UV photometric observations of the planet and its satellites, Pioneer 10 and 11 imaging polarimetry, the plasma analyzer experiment on the two probes, and observations of energetic Jovian electrons and protons. Individual items are announced in this issue.

Gehrels, T.↗

TurboTech Technical Evaluation Automated System

TurboTech software is a Web-based process that simplifies and semiautomates technical evaluation of NASA proposals for Contracting Officer's Technical Representatives (COTRs). At the time of this reporting, there have been no set standards or systems for training new COTRs in technical evaluations. This new process provides boilerplate text in response to interview style questions. This text is collected into a Microsoft Word document that can then be further edited to conform to specific cases. By providing technical language and a structured format, TurboTech allows the COTRs to concentrate more on the actual evaluation, and less on deciding what language would be most appropriate. Since the actual word choice is one of the more time-consuming parts of a COTRs job, this process should allow for an increase in quantity of proposals evaluated. TurboTech is applicable to composing technical evaluations of contractor proposals, task and delivery orders, change order modifications, requests for proposals, new work modifications, task assignments, as well as any changes to existing contracts.

Tiffany, Dorothy J.↗

Logic Programming with Extensible Types

Logic programming allows structuring code in terms of predicates or relations, rather than functions. Although logic programming languages present advantages in terms of declarativeness and conciseness, the introduction of static types has not become part of most popular logic programming languages, increasing the difficulty of testing and debugging of logic programming code. This paper demonstrates how to implement logic programming in Haskell, thus empowering logic programs with types, and functional programs with relations or predicates. We do so by combining three ideas. First, we use extensible types to generalize a type by a parameter type function. Second, we use a sum type as an argument to introduce optional variables in extensible types. Third, we implement a unification algorithm capable of working with any data structure, provided that certain operations are implemented for the given type. We demonstrate our proposal via a series of increasingly complex examples inspired by educational texts in logic programming, and leverage the host language's features to make new notation convenient for users, showing that the proposed approach is not just technically possible but also practical.

logic programming↗

ncompare: A Python Package for Comparing netCDF Structures

Earth science researchers and data engineers have a common problem: they often need to compare data files to see what is different between them. A lot of time is spent developing code to test differences. When it comes to comparing multidimensional data file formats like netCDFs (Network Common Data Form), this is particularly challenging and time-consuming, since there is frequently a need to evaluate the differences between dimension sizes, variable structures, and variable attributes, especially for regression testing. Since netCDFs are widely used in Earth science — with climate models, oceanographic or atmospheric reanalyses, and observational data — improved means of evaluating netCDF files can help enable a wide range of applications. We have developed a reusable open source approach through `ncompare`, which is a Python package for comparing netCDF structures [[https://github.com/nasa/ncompare]]. The `ncompare` tool compares the structure of two Network Common Data Form (NetCDF) files at the command line. It facilitates rapid comparisons by generating a formatted display of the matching and non-matching groups, variables, and associated metadata between two NetCDF datasets. The user has the option to colorize the terminal output for ease of viewing, and `ncompare` can optionally save comparison reports in text, comma-separated value (CSV), and/or Microsoft Excel formats. Despite the availability of tools (such as ncmpidiff or nccmp) that compare the values of variables, there was not previously a readily available, Python-based tool for rapid visual comparisons of group and variable structures, attributes, and chunking. `ncompare` was developed at NASA’s Atmospheric Science Data Center (ASDC) and is a collaboration with NASA Openscapes [[https://nasa-openscapes.github.io]] mentors across 11 of NASA’s data centers. Openscapes’ overarching vision is to support scientific researchers using NASA Earthdata as they migrate their workflows to the cloud. Relevant links: - https://github.com/nasa/ncompare - https://github.com/pyOpenSci/software-submission/issues/146 - https://nasa-openscapes.github.io

Daniel Kaufman↗

Tectonic domains in the Eastern Hemisphere of Mars

The definition of boundaries of discrete structural provinces on the surface of Mars has previously been made by the assumptions of circular or radial symmetry (in the case of the Tharsis olateau), by artificial quadrangle boundaries for regional studies, or simply by regional geographical features. Much of the planetary structural mapping has been presented in a line or spot format in existing consortium data. Methods are being generated to convert the detailed maps of tectonic features to a format that can be used with standard image processing techniques. In this manner such data can be more readily compared to age and other attributes deduced from geological mapping, gravity results, and topography. The 24 photomosaics covering the Eastern Hemisphere of Mars have already been examined for four types of structural features: erosional remnants, ridges, graben, and scarps. When digitized, each feature was flagged according to feature type, azimuth and length. These values were stored as text files on a quad-by-quad basis for each quad studied.

Maxwell, Ted A.↗

Knowledge-based machine indexing from natural language text: Knowledge base design, development, and maintenance

One strategy for machine-aided indexing (MAI) is to provide a concept-level analysis of the textual elements of documents or document abstracts. In such systems, natural-language phrases are analyzed in order to identify and classify concepts related to a particular subject domain. The overall performance of these MAI systems is largely dependent on the quality and comprehensiveness of their knowledge bases. These knowledge bases function to (1) define the relations between a controlled indexing vocabulary and natural language expressions; (2) provide a simple mechanism for disambiguation and the determination of relevancy; and (3) allow the extension of concept-hierarchical structure to all elements of the knowledge file. After a brief description of the NASA Machine-Aided Indexing system, concerns related to the development and maintenance of MAI knowledge bases are discussed. Particular emphasis is given to statistically-based text analysis tools designed to aid the knowledge base developer. One such tool, the Knowledge Base Building (KBB) program, presents the domain expert with a well-filtered list of synonyms and conceptually-related phrases for each thesaurus concept. Another tool, the Knowledge Base Maintenance (KBM) program, functions to identify areas of the knowledge base affected by changes in the conceptual domain (for example, the addition of a new thesaurus term). An alternate use of the KBM as an aid in thesaurus construction is also discussed.

Genuardi, Michael T.↗

Understanding Friction Stir Welding

This Technical Memorandum explains the friction stir welding process in terms of two basic concepts: the concentration of deformation in a shear surface enveloping the tool and the composition of the overall plastic flow field around the tool from simple flow field components. It is demonstrated how weld structure may be understood and torque, drag, and lateral tool forces may be estimated using these concepts. Some discrepancies between computations and accompanying empirical data are discussed in the text. This work is intended to be helpful to engineers in diagnosing problems and advancing technology.

Nunes, A. C., Jr.↗

Environmental projects. Volume 12: Friable asbestos abatement, GDSCC

The Goldstone Deep Space Communications Complex (GDSCC) is part of the NASA Deep Space Network, one of the world's largest and most sensitive scientific telecommunications and radio navigation networks. Activities at the GDSCC are carried out in support of six large parabolic dish antennas. These activities may give rise to a variety of environmental hazards, particularly the danger of exposure of GDSCC personnel to asbestos fibers that have been shown to be responsible for such serious ailments as asbestosis, lung cancer, and mesothelioma. Asbestos-containing materials (ACM's) were used in the construction of many of the approximately 100 buildings and structures that were built at the GDSCC during a 30-year period from the 1950s through 1980s. The friable asbestos-abatement program at the GDSCC is presented which consists of text, illustrations, and tables that describe the friable asbestos abatement carried out at the GDSCC from December 21, 1988 through May 11, 1989.

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Mirador: A Simple, Fast Search Interface for Remote Sensing Data

A major challenge for remote sensing science researchers is searching and acquiring relevant data files for their research projects based on content, space and time constraints. Several structured query (SQ) and hierarchical navigation (HN) search interfaces have been develop ed to satisfy this requirement, yet the dominant search engines in th e general domain are based on free-text search. The Goddard Earth Sci ences Data and Information Services Center has developed a free-text search interface named Mirador that supports space-time queries, inc luding a gazetteer and geophysical event gazetteer. In order to compe nsate for a slightly reduced search precision relative to SQ and HN t echniques, Mirador uses several search optimizations to return result s quickly. The quick response enables a more iterative search strateg y than is available with many SQ and HN techniques.

Lynnes, Christopher↗

ATLAS, an integrated structural analysis and design system. Volume 3: User's manual, input and execution data

The input data and execution control statements for the ATLAS integrated structural analysis and design system are described. It is operational on the Control Data Corporation (CDC) 6600/CYBER computers in a batch mode or in a time-shared mode via interactive graphic or text terminals. ATLAS is a modular system of computer codes with common executive and data base management components. The system provides an extensive set of general-purpose technical programs with analytical capabilities including stiffness, stress, loads, mass, substructuring, strength design, unsteady aerodynamics, vibration, and flutter analyses. The sequence and mode of execution of selected program modules are controlled via a common user-oriented language.

Dreisbach, R. L.↗

Observation model and parameter partials for the JPL VLBI parameter estimation software MODEST/1991

A revision is presented of MASTERFIT-1987, which it supersedes. Changes during 1988 to 1991 included introduction of the octupole component of solid Earth tides, the NUVEL tectonic motion model, partial derivatives for the precession constant and source position rates, the option to correct for source structure, a refined model for antenna offsets, modeling the unique antenna at Richmond, FL, improved nutation series due to Zhu, Groten, and Reigber, and reintroduction of the old (Woolard) nutation series for simulation purposes. Text describing the relativistic transformations and gravitational contributions to the delay model was also revised in order to reflect the computer code more faithfully.

Sovers, O. J.↗

The 1987-1988 advanced space design projects: Results from the fall semester of 1987 and the spring semester of 1988

Students in Aerospace Engineering (ASE) and Mechanical Engineering (ME) at the University of Texas at Austin completed eight separate design projects under the sponsorship of the NASA/USRA Advanced Space Design Program. During the Fall semester of 1987, ASE and ME students worked on various aspects of a 'bootstrap' lunar base. ASE students concentrated on the overall definition of the base while the ME team designed a convertible lunar lander lower stage. Six design projects were executed during the spring semester of 1988. Aerospace engineering students designed a fast Mars mission crew transfer vehicle, an Earth-orbiting transportation node to support the lunar base, a lunar base construction shack/initial habitat vehicle, and carried out a systems assessment aimed at arresting ozone depletion in the Earth's atmosphere. The ME students designed a lunar surface personnel navigation system and investigated radiation shielding structures for a lunar base. The design objectives, a summary of the results, and selected comments are given concerning each of the projects. Due to the number of projects completed, the reader should refer to the text of the final project reports for additional and detailed information.

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EXTENSIBLE DATABASE FRAMEWORK FOR MANAGEMENT OF UNSTRUCTURED AND SEMI-STRUCTURED DOCUMENTS

Method and system for querying a collection of Unstructured or semi-structured documents to identify presence of, and provide context and/or content for, keywords and/or keyphrases. The documents are analyzed and assigned a node structure, including an ordered sequence of mutually exclusive node segments or strings. Each node has an associated set of at least four, five or six attributes with node information and can represent a format marker or text, with the last node in any node segment usually being a text node. A keyword (or keyphrase) is specified. and the last node in each node segment is searched for a match with the keyword. When a match is found at a query node, or at a node determined with reference to a query node, the system displays the context andor the content of the query node.

Gawdiak, Yuri O.↗

LANDSAT multispectral scanner computer-compatible tape format, version 1.0

Unlike previous LANDSAT computer compatible tape (CCT) formats, the standard format of CCT's now includes a comprehensive field location and data description information superstructure composed of four records. The volume descriptor record, the text record, and the file pointer record reside in a volume directory file, which generally describes the data configuration and provides pointers to each data file. The file descriptor record for each data file describes the data structure within the file and provides pointers to certain fields within the file. These superstructure records primarily supply information about the data on the CCT as opposed to carrying the data themselves. The EROS Data Center's LANDSAT CCT version 1.0 product is presented which conforms to the concepts of the standard format as much as is possible with existing EDC systems.

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