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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 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1979

Meta assembler enhancements and generalized linkage editor

A meta Assembler for NASA was developed. The initial development of the Meta Assembler for the SUMC was performed. The capabilities included assembly for both main and micro level programs. A period of checkout and utilization to verify the performance of the Meta Assembler was undertaken. Additional enhancements were made to the Meta Assembler which expanded the target computer family to include architectures represented by the PDP-11, MODCOMP 2, and Raytheon 706 computers.

Source record↗
NASA NTRS1972

Viscoelastic cationic polymers containing the urethane linkage

A method for the synthesis and manufacturing of elastomeric compositions and articles containing quaternary nitrogen centers and condensation residues along the polymeric backbone of the centers is presented. Linear and cross-linked straight chain and block polymers having a wide damping temperature range were synthesized. Formulae for the viscoelastic cationic polymers are presented.

Rembaum, A.↗
NASA NTRS1983

Aromatic Polyimides With Group VI Linkages

New polymer system combines thermal and solvent resistant properties of aromatic polyimides with processability of PPX polymers. PPX polymers include polyphenylene oxide, polyphenylene sulfide, and polyphenylene sulfone classes. Generally more processable by hot melt or thermoplastic techniques than aromatic polyimides. PPX systems more susceptible to attack by solvents and have lower glass transition temperatures than PI group.

St. Clair, T. L.↗
NASA NTRS1982

Linkage between gravity perception and response in the grass leaf-sheath pulvinus

Cellulose synthesis inhibitors 2,6-dichlorobenzonitrile and coumarin inhibit the normal gravitropic response of the leaf-sheath pulvini in several grasses. These inhibitors induce thickenings that are mostly distributed in the radial walls. Their distribution patterns follow a previously published equation that describes the geometry of asymmetric growth in the leaf-sheath pulvinus. It is proposed that radial transport of growth promotors may account for the observed asymmetric growth rather than the classical concept of lateral downward transport in an horizontally placed shoot. Electron microscopic observation of an interaction between the tonoplast membrane and statoliths suggests that such an interaction might be a basis for gravity perception in grass leaf-sheath pulvini.

Dayanandan, P.↗
NASA NTRS1985

Improving management decision processes through centralized communication linkages

Information flow is a critical element to intelligent and timely decision-making. At NASA's Johnson Space Center the flow of information is being automated through the use of a centralized backbone network. The theoretical basis of this network, its implications to the horizontal and vertical flow of information, and the technical challenges involved in its implementation are the focus of this paper. The importance of the use of common tools among programs and some future concerns related to file transfer, graphics transfer, and merging of voice and data are also discussed.

Simanton, D. F.↗
NASA NTRS1985

Cockpit resource management - Exploring the attitude-performance linkage

Measured attitudes regarding cockpit management were contrasted for pilots whose line flying performance was independently evaluated by check airmen as above or below average. A highly significant discriminant function was obtained indicating that these attitudes are significant predictors of behavior. The performance of 95.7 percent of the pilots was correctly classified by the analysis. Implications of the results for cockpit resource management training and pilot selection are discussed.

Helmreich, R. L.↗
NASA NTRS1986

U.S. experience in satellite servicing and linkage to the Space Station era

A history of on-orbit servicing and repair is given with emphasis placed on the Solar Maximum Repair Mission. The experience gained thus far in on-orbit servicing and the design of the Space Station's servicing capabilities impose the following requirements on users: (1) satellites must have a standard grapple for capture and a standard berthing interface, (2) Space Station safety requirements must meet to preclude damage to the Space Station or injury to the EVA crew, (3) sensitive instruments will need to implement remotely controlled protective devices to prevent damage, and (4) satellite thermal systems must be designed to maintain survival temperatures during transfer from orbit to the Space Station servicing facility.

Browning, R. K.↗
NASA NTRS1989

Application of finite-element methods to dynamic analysis of flexible spatial and co-planar linkage systems, part 2

An approach is described to modeling the flexibility effects in spatial mechanisms and manipulator systems. The method is based on finite element representations of the individual links in the system. However, it should be noted that conventional finite element methods and software packages will not handle the highly nonlinear dynamic behavior of these systems which results form their changing geometry. In order to design high-performance lightweight systems and their control systems, good models of their dynamic behavior which include the effects of flexibility are required.

Dubowsky, Steven↗
NASA NTRS1989

Oligomerization of deoxynucleoside-biphosphate dimers - Template and linkage specificity

The oligomerization of the activated 3-prime-5-prime pyrophosphate-linked dimer, pdAppdAp, is presently noted to be selectively favored by a poly(U) template over the 3-prime-3-prime and 5-prime-5-prime linked dimers. Both overall yields and the production of the longest oligomers were markedly stimulated by poly(U)'s presence; in its absence, the 5-prime-5-prime linked dimer became the most reactive, yielding chains of the order of 60 monomer-unit lengths. Remarkable self-organization properties are noted for the 5-prime-5-prime dimer of pdAp.

Visscher, J.↗
NASA NTRS1988

Position requirements for space station personnel and linkages to portable microcomputer performance assessment

The development and use of a menu of performance tests that can be self-administered on a portable microcomputer are investigated. In order to identify, develop, or otherwise select the relevant human capabilities/attributes to measure and hence include in the performance battery, it is essential that an analysis be conducted of the jobs or functions that will be performed throughout a space shuttle mission. The primary job analysis instrument, the Position Analysis Questionnaire (PAQ), is discussed in detail so the reader will have sufficient background for understanding the application of the instrument to the various work activities included within the scope of the study, and the derivation of the human requirements (abilities/attributes) from the PAQ analyses. The research methodology is described and includes the procedures used for gathering the PAQ data. The results are presented in detail with specific emphasis on identifying critical requirements that can be measured with a portable computerized assessment battery. A discussion of the results is given with implications for future research.

Jeanneret, P. R.↗
NASA NTRS1992

Ocean-atmospheric linkages

This chapter focuses on the role of the ocean in the global carbon cycle on the time scale of decades to centuries. The input rate of CO2 to the atmosphere due to fossil fuel burning and deforestation has continued to increase over the last century. To balance the global carbon budget, a sink is required whose magnitude is changing on similar time scales. We have sought to identify aspects of the ocean system that are capable of responding on decadal time scales, to examine our present ability to model such changes, and to pinpoint ways in which this ability could be improved. Many other important aspects of the ocean's role in global change are not addressed, including the importance of oceanic heat transport and thermal inertia to the climate system, biogeochemical cycling of elements other than carbon, and the importance of the ocean as a source or sink of trace gases.

Rintoul, Stephen R.↗
NASA NTRS1998

Synthesis and Characterization of Polyimides with Ether Linkages

A series of polyimides derived from a newly synthesized diamine, namely, 4,4-bis(4-aminophenoxy)-2,2-dimethylbiphenyl (BAPD), were developed and characterized. Their physical and thermal properties were compared to polyimides based on'commercially available 2,2-bis(4-(4-aminophenoxy)phenyl)propane (BAPP).

Chuang, Kathy C.↗
NASA NTRS1999

Linkages Between Multiscale Global Sea Surface Temperature Change and Precipitation Variabilities in the US

A growing number of evidence indicates that there are coherent patterns of variability in sea surface temperature (SST) anomaly not only at interannual timescales, but also at decadal-to-inter-decadal timescale and beyond. The multi-scale variabilities of SST anomaly have shown great impacts on climate. In this work, we analyze multiple timescales contained in the globally averaged SST anomaly with and their possible relationship with the summer and winter rainfall in the United States over the past four decades.

Lau, K. M.↗
NASA NTRS2002

Visions 2025 and Linkage to NEXT

This talk will describe the progress to date on creating a science-driven vision for the NASA Earth Science Enterprise (ESE) in the post-2010 period. This effort began in the Fall of 2001 by organizing five science workgroups with representatives from NASA, academia and other agencies: Long-Term Climate, Medium-Term Climate, Extreme Weather, Biosphere & Ecosystems, and Solid Earth, Ice Sheets, & Sea Level. Each workgroup was directed to scope out one Big Question, including not just the science but the observational and modeling requirements, the information system requirements, and the applications and benefits to society. This first set of five Big Questions is now in hand and has been presented to the ESE Director. It includes: water resources, intraseasonal predictability, tropical cyclogenesis, invasive species, and sea level. Each of these topics will be discussed briefly. How this effort fits into the NEXT vision exercise and into Administrator O'Keefe's new vision for NASA will also be discussed.

Wiscombe, W.↗