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NASA NTRS1985

Transition in a disturbed environment

The title of this presentation is the title of our research grant. While transition study is the objective of the work, the results to date are principally on the properties of turbulent boundary layers at low Reynolds numbers are discussed. Testing was done in a small return wind tunnel. Mean boundary layer development is given. The skin friction behavior of the turbulent points are considered. No standard laminar flow was observed. Furthermore, the turbulent mean flow data seem reasonable for the elevated disturbance levels of the tests in the sense that there is no discernible wake component to any of the profiles and that the variation of skin friction with R sub theta is consistent with zero wake strength. The no-grid data are in all likelihood transitional.

Reshotko, E.↗

NASA NTRS1985

Electrical safety requirements: Implications for the module designer

Commercial photovoltaic array installations, which include residential and intermediate applications, are subject to building and electrical codes and to product safety standards. The National Electrical Code (NEC) Article 690, titled Solar Photovoltaic Systems, contains provisions defining acceptable levels of system safety and emphasizes the system design and its installation. The Underwriters Laboratories, Inc. (UL), document titled: Proposed First Edition of the Standard for Flat Plate Photovoltaic Modules and Panels, UL-1703, identifies module and panel construction requirements that ensure product safety. Together these documents describe requirements intended to minimize hazards such as shock and fire. Although initial focus of these requirements is on single crystal silicon modules, they are generic in nature, and are equally applicable to high voltage ( 30 Vdc), multikilowatt, thin film systems. A major safety concern is insulation breakdown within the module or array wiring system, or discontinuities within the electrical conductors. These failures can result in ground faults, in circuit arcs, or exposure to hazardous electrical parts. Safeguards are discussed.

Sugimura, R. S.↗

NASA NTRS1985

AI at Ames: Artificial Intelligence research and application at NASA Ames Research Center, Moffett Field, California, February 1985

Charts are given that illustrate function versus domain for artificial intelligence (AI) applications and interests and research area versus project number for AI research. A list is given of project titles with associated project numbers and page numbers. Also, project descriptions, including title, participants, and status are given.

Andrews, Alison E.↗

NASA NTRS1993

NASA directives master list and index

This Handbook sets forth in two parts the following information for the guidance of users of the NASA Management Directives System. Part A is a master list of management directives in force as of March 31, 1993. Chapter 1 contains introductory informative material on how to use this Handbook. Chapter 2 is a complete master list of Agencywide management directives, describing each directive by type, number, effective date, expiration date, title, and organization code of the office responsible for the directive. Chapter 3 includes a consolidated numerical list of all delegations of authority and a breakdown of such delegation by the office or installation to which special authority is assigned. Chapter 4 sets forth a consolidated list of all NASA Handbooks (NHB's) and important footnotes covering the control and ordering of such documents. Chapter 5 is a consolidated list of NASA management directives applicable to the Jet Propulsion Laboratory. Chapter 6 is a consolidated list of NASA management directives published in the Code of Federal Regulations. Complementary manuals to the NASA Management Directives System are described in Chapter 7. Part B is the index to NASA management directives in force as of March 31, 1993. This part contains an in-depth alphabetical index to all NASA management directives other than Handbooks. NHB's 1610.6, 'NASA Personnel Security Handbook,' 1620.3, 'NASA Physical Security Handbook,' 1640.4, 'NASA Information Security Program,' 1900.1, 'Standards of Conduct for NASA Employees,' 5103.6, 'Source Evaluation Board Handbook,' and 7400.1, 'Budget Administration Manual,' are indexed in-depth. All other NHB's are indexed by titles only.

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NASA NTRS1992

Index of NASA prefixed forms

This Handbook sets forth information for the guidance of all users of the NASA Forms Management Program System. It is issued in accordance with the Federal Information Resources Management Regulation (FIRMR), Subpart 201-9.1. This Handbook sets forth an alpha-functional index of NASA-prefixed forms by title, identifying number, and unit of issue. The automated processing two-letter code (NF) has been substituted for the spelling out of the NASA form-prefix preceding the form number. To indicate a description in lieu of a distinct title, the entire reference under the Form Title/Description column has been enclosed in parentheses. A list of current forms, shown by number and page, is included for cross-reference and to preclude the ordering of those forms which have been deleted from the system. This Handbook will be updated, as appropriate. NHB 1420.2H dated July 1986, is cancelled.

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NASA NTRS1991

An overview of the text propagation effects for land-mobile-satellite systems: Experimental and modeling results

We present an overview of the contents of the text having the above title and which is now in the form of a preliminary document titled, 'Propagation Handbook for Land-Mobile-Satellite Systems-Preliminary.' At this writing the text is undergoing peer review, and the final revised manuscript will be published in the near future as a NASA document. The text was inspired by a series of Land-Mobile-Satellite System (LMSS) experiments by the authors and other investigators at UHF and L-Band. The rationale for its writing is to place in a single document an overview of the previous propagation related salient experimental and modeling results pertaining to LMSS scenarios. It is apparent that LMSS propagation at UHF and L-Band can be seriously degraded because of attenuation (e.g., greater than 10 dB) caused by roadside tree shadowing. The extent of attenuation is shown to depend on such factors at the elevation angle to the satellite, the bearing of the line-of-signt path to the satellite relative to the line of roadside trees, the side of the road in which the vehicle is driven, the season, and the frequency. Multipath effects during line-of-sight communications are shown to cause less serious fading (e.g., smaller than 3 dB for 90 percent of the driving distance).

Goldhirsh, Julius↗

NASA NTRS1998

How to Introduce the Imperfection Sensitivity Concept into Design 2

The previous review on stochastic buckling of structures was written by Amazigo in 1976. The present review summarizes some of the developments which took place in recent two decades. A brief overview is given of the effect on uncertainty in the initial geometric imperfections, elastic moduli, applied forces, and thickness variation. For the benefit of the thinking reader, the review has a critical nature. Present essay should be viewed as a direct continuation of our previous paper (1983) with the same title. In order not to repeat what was covered there, it appears instructive to read it although not necessarily prior to dwelling on this article. Accordingly the title is appended with the serial number. It is not promised that the third review will follow since the university science, both fortunately and unfortunately, stands on three things: relevance, interest, and grants.

Elishakoff, Isaac↗

NASA NTRS1998

Bubble Dynamics, Two-Phase Flow, and Boiling Heat Transfer in Microgravity

This report contains two independent sections. Part one is titled "Terrestrial and Microgravity Pool Boiling Heat Transfer and Critical heat flux phenomenon in an acoustic standing wave." Terrestrial and microgravity pool boiling heat transfer experiments were performed in the presence of a standing acoustic wave from a platinum wire resistance heater using degassed FC-72 Fluorinert liquid. The sound wave was created by driving a half wavelength resonator at a frequency of 10.15 kHz. Microgravity conditions were created using the 2.1 second drop tower on the campus of Washington State University. Burnout of the heater wire, often encountered with heat flux controlled systems, was avoided by using a constant temperature controller to regulate the heater wire temperature. The amplitude of the acoustic standing wave was increased from 28 kPa to over 70 kPa and these pressure measurements were made using a hydrophone fabricated with a small piezoelectric ceramic. Cavitation incurred during experiments at higher acoustic amplitudes contributed to the vapor bubble dynamics and heat transfer. The heater wire was positioned at three different locations within the acoustic field: the acoustic node, antinode, and halfway between these locations. Complete boiling curves are presented to show how the applied acoustic field enhanced boiling heat transfer and increased critical heat flux in microgravity and terrestrial environments. Video images provide information on the interaction between the vapor bubbles and the acoustic field. Part two is titled, "Design and qualification of a microscale heater array for use in boiling heat transfer." This part is summarized herein. Boiling heat transfer is an efficient means of heat transfer because a large amount of heat can be removed from a surface using a relatively small temperature difference between the surface and the bulk liquid. However, the mechanisms that govern boiling heat transfer are not well understood. Measurements of wall temperature and heat flux near the wall would add to the database of knowledge which is necessary to understand the mechanisms of nucleate boiling. A heater array has been developed which contains 96 heater elements within a 2.5 mm square area. The temperature of each heater element is held constant by an electronic control system similar to a hot-wire anemometer. The voltage that is being applied to each heater element can be measured and digitized using a high-speed Analog to Digital (A/D) converter, and this digital information can be compiled into a series of heat-flux maps. Information for up to 10,000 heat flux maps can be obtained each second. The heater control system, the A/D system and the heater array construction are described in detail. Results are presented which show that this is an effective method of measuring the local heat flux during nucleate and transition boiling. Heat flux maps are obtained for pool boiling in FC-72 on a horizontal surface. Local heat flux variations are shown to be three to six times larger than variations in the spatially averaged heat flux.

Chung, Jacob N.↗

NASA NTRS1998

Towards a Theory of Tropical/Midlatitude Mass Exchange from the Earth's Surface through the Stratosphere

The main findings of this research project have been the following: (1) there is a significant feedback from the stratosphere on tropospheric dynamics, and (2) a detailed analysis of the interaction between tropical and polar wave breaking in controlling stratospheric mixing. Two papers are were written and are included. The first paper is titled, "A New Perspective on the Dynamical Link Between the Stratosphere and Troposphere." Atmospheric processes of tropospheric origin can perturb the stratosphere, but direct feedback in the opposite direction is usually assumed to be negligible, despite the troposphere's sensitivity to changes in the release of wave activity into the stratosphere. Here, however, we present evidence that such a feedback exists and can be significant. We find that if the wintertime Arctic polar stratospheric vortex is distorted, either by waves propagating upward from the troposphere or by eastward-travelling stratospheric waves, then there is a concomitant redistribution of stratospheric potential vorticity that induces perturbations in key meteorological fields in the upper troposphere. The feedback is large despite the much greater mass of the troposphere: it can account for up to half of the geopotential height anomaly at the tropopause. Although the relative strength of the feedback is partly due to a cancellation between contributions to these anomalies from lower altitudes, our results imply that stratospheric dynamics and its feedback on the troposphere are more significant for climate modelling and data assimilation than was previously assumed. The second article is titled "Diagnosing the Polar Excitation of Subtropical Waves in the Stratosphere". The poleward migration of planetary scale tongues of subtropical air has often been associated with intense polar vortex disturbances in the stratosphere. This question of vortex influence is reexamined from a potential vorticity (PV) perspective. Anomalous geopotential height and wind fields associated solely with vortex PV anomalies are derived and their impact on the stratospheric subtropical circulation is evaluated. Combined PV inversion and Contour Advection (CA) calculations indicate that transient large scale disturbances of the polar vortex do have a far reaching impact that extends beyond the midlatitude surf zone all the way to the subtropics. This vortex influence is clearly non-local so that even simple wave 2 distortions that leave the vortex well confined within the midlatitudes are observed to excite subtropical waves. Treating subtropical PV as active tracers also showed that upon entrainment, these large scale tongues of low PV air also influenced the dynamics of their own poleward migration.

Hartley, Dana↗

NASA NTRS2000

SeaWiFS Postlaunch Technical Report Series: Cumulative Index: Volumes 1-5 - Volume 6

The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) is the follow-on ocean color instrument to the Coastal Zone Color Scanner (CZCS), which ceased operations in 1986, after an eight-year mission. SeaWiFS was launched on 1 August 1997, on the OrbView-2 satellite, built by Orbital Sciences Corporation (OSC). The SeaWiFS Project at the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) undertook the responsibility of documenting all aspects of this mission, which is critical to the ocean color and marine science communities. The start of this documentation was titled the SeaWiFS Technical Report Series, which ended after 43 volumes were published. A follow-on series was started, titled the SeaWiFS Postlaunch Technical Report Series. This particular volume serves as a reference, or guidebook, to the previous five volumes and consists of four sections including an errata, an index to key words and phrases, a list of acronyms used, and a list of all references cited. The editors will publish a cumulative index of this type after every five volumes.

Firestone, Elaine R.↗

NASA NTRS2001

SeaWiFS Postlaunch Technical Report Series Cumulative Index

The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) is the follow-on ocean color instrument to the Coastal Zone Color Scanner (CZCS), which ceased operations in 1986, after an eight-year mission. SeaWiFS was launched on 1 August 1997, onboard the OrbView-2 satellite, built by Orbital Sciences Corporation (OSC). The SeaWiFS Project at the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC), undertook the responsibility of documenting all aspects of this mission, which is critical to the ocean color and marine science communities. The start of this documentation was titled the SeaWiFS Technical Report Series, which ended after 43 volumes were published. A follow-on series was started, titled the SeaWiFS Postlaunch Technical Report Series. This particular volume of the so-called "Postlaunch Series" serves as a reference, or guidebook, to the previous 11 volumes and consists of 5 sections including an errata, an addendum, an index to key words and phrases, a list of acronyms used, and a list of all references cited. The editors will publish a cumulative index of this type after every five volumes.

Hooker, Stanford B.↗

NASA NTRS2002

Dynamics of Planetary Atmospheres

The PI had nineteen papers either published or in press in 1999 through early 2002. Ten of these (Thomas et al. 1999, Geisler et al. 1999, Vasavada et al. 1999, Little et al. t999, Gierasch et al. 2000, Ingersoll et al. 2000, Thomas et al. 2000, Dyudina et al. 2001, Chang et al. 2001, Wang and Ingersoll 2002) were largely supported by the Mars Global Surveyor project and the Galileo project. The other nine papers were largely supported under this grant, and are listed in boldface below. Six of the nine are research papers. Their titles and abstracts are reproduced below. The New Solar System chapter and the Meteorology at the Millennium chapter are review articles, and the World Book Encyclopedia chapter is a popular article. Their title pages and abstracts are also reproduced below.

Ingersoll, Andrew P.↗

NASA NTRS2003

SeaWiFS Postlaunch Technical Report Series Cumulative Index: Volumes 1-23

The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) is the follow-on ocean color instrument to the Coastal Zone Color Scanner (CZCS), which ceased operations in 1986, after an eight-year mission. SeaWiFS was launched on 1 August 1997, onboard the OrbView-2 satellite, built by Orbital Sciences Corporation (OSC). The SeaWiFS Project at the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC), undertook the responsibility of documenting all aspects of this mission, which is critical to the ocean color and marine science communities. The start of this documentation was titled the SeaWiFS Technical Report Series, which ended after 43 volumes were published. A follow-on series was started, titled the Sea WiFS Postlaunch Technical Report Series. This particular volume of the so-called Postlaunch Series serves as a reference, or guidebook, to the previous 23 volumes and consists of 4 sections including an errata, an index to key words and phrases, a list of acronyms used, and a list of all references cited. The editors will publish a cumulative index of this type after every five volumes.

Hooker, Stanford B.↗

NASA NTRS2004

RTO Technical Publications: A Quarterly Listing

The titles of five reports are listed here, together with an abstract for each. The titles include: 1) 'Spectral Models of Kuiper Belt Objects and Centaurs'; 2) 'Simulation of and for Military Decision Making'; 3) 'Abundance of the Radioactive Be-10 in the Cosmic Radiation up to 2 GeV/nucleon with the Balloon-borne Instrument ISOMAX1998'; 4) 'Optical Air Flow Measurements in Flight'; 5) 'Flight Test Measurement Techniques for Laminar Flow'.

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NASA NTRS2004

Full Text Searching and Customization in the NASA ADS Abstract Service

The NASA-ADS Abstract Service provides a sophisticated search capability for the literature in Astronomy, Planetary Sciences, Physics/Geophysics, and Space Instrumentation. The ADS is funded by NASA and access to the ADS services is free to anybody worldwide without restrictions. It allows the user to search the literature by author, title, and abstract text. The ADS database contains over 3.6 million references, with 965,000 in the Astronomy/Planetary Sciences database, and 1.6 million in the Physics/Geophysics database. 2/3 of the records have full abstracts, the rest are table of contents entries (titles and author lists only). The coverage for the Astronomy literature is better than 95% from 1975. Before that we cover all major journals and many smaller ones. Most of the journal literature is covered back to volume 1. We now get abstracts on a regular basis from most journals. Over the last year we have entered basically all conference proceedings tables of contents that are available at the Harvard Smithsonian Center for Astrophysics library. This has greatly increased the coverage of conference proceedings in the ADS. The ADS also covers the ArXiv Preprints. We download these preprints every night and index all the preprints. They can be searched either together with the other abstracts or separately. There are currently about 260,000 preprints in that database. In January 2004 we have introduced two new services, full text searching and a personal notification service called "myADS". As all other ADS services, these are free to use for anybody.

Eichhorn, G.↗

NASA NTRS2003

Approaches to Cycle Analysis and Performance Metrics

The following notes were prepared as part of an American Institute of Aeronautics and Astronautics (AIAA) sponsored short course entitled Air Breathing Pulse Detonation Engine (PDE) Technology. The course was presented in January of 2003, and again in July of 2004 at two different AIAA meetings. It was taught by seven instructors, each of whom provided information on particular areas of PDE research. These notes cover two areas. The first is titled Approaches to Cycle Analysis and Performance Metrics. Here, the various methods of cycle analysis are introduced. These range from algebraic, thermodynamic equations, to single and multi-dimensional Computational Fluid Dynamic (CFD) solutions. Also discussed are the various means by which performance is measured, and how these are applied in a device which is fundamentally unsteady. The second topic covered is titled PDE Hybrid Applications. Here the concept of coupling a PDE to a conventional turbomachinery based engine is explored. Motivation for such a configuration is provided in the form of potential thermodynamic benefits. This is accompanied by a discussion of challenges to the technology.

Parson, Daniel E.↗

NASA NTRS2007

An Online Resource for Flight Test Safety Planning

A viewgraph presentation describing an online database for flight test safety techniques is shown. The topics include: 1) Goal; 2) Test Hazard Analyses; 3) Online Database Background; 4) Data Gathering; 5) NTPS Role; 6) Organizations; 7) Hazard Titles; 8) FAR Paragraphs; 9) Maneuver Name; 10) Identified Hazard; 11) Matured Hazard Titles; 12) Loss of Control Causes; 13) Mitigations; 14) Database Now Open to the Public; 15) FAR Reference Search; 16) Record Field Search; 17) Keyword Search; and 18) Results of FAR Reference Search.

Lewis, Greg↗

NASA NTRS2004

Synthesis and Characterization of Ru(II) Tris(1,1O-phenanthroline)-Electron Acceptor Dyads Incorporating the 4-benzoyl-N-methylpyridinium Cation or N-Benzyl-N'-methyl-viologen. Improving the Dynamic Range, Sensitivity and Response Time of Sol-Gel Based Optical Oxygen Sensors

The title compounds (1 and 2, above) were synthesized by Sonogashira coupling reactions of appropriate Ru(1I) complexes with the electron a cceptors. Characterization was conducted in solution and in frozen ma trices. Finally, the title compounds were evaluated as dopants of sol-gel materials. It was found that the intramolecular quenching efficie ncy of 4-benzoyl-Nmethylpyridinium cation in solution depends on the solvent: photoluminescence is quenched completely in CH,CN, but not i n methanol or ethanol. On the other hand, intramolecular emission que nching by 4-benzyl-N-methyl viologen is complete in all solvents. The difference between the two quenchers is traced electrochemically to t he solvation of the 4-benzoyl-Nmethylpyridiniums by alcohol. In froze n matrices or adsorbed on the surfaces of silica aerogel, both Ru(I1) complex/electron acceptor dyads of this study are photoluminescent, and the absence of quenching has been traced to the environmental rigi dity. When doped aerogels are cooled at 77 K, the emission intensity increases by approximately 4x, and the spectra shift to the blue, analogous to what is observed with Ru(I1) complexes in solutions undergoi ng fluid-to-rigid transition. However, in contrast to frozen solution s, the luminescent moieties in the bulk of aerogels kept at low tempe ratures are still accessible to gas-phase quenchers diffusing through the mesopores, leading to more sensitive platforms for sensors than o ther room-temperature configurations. Thus the photoluminescence of o ur Ru(I1) complex dyads adsorbed on aerogel is quenchable by O2 both at room temperature and at 77 K. Furthermore, it was also found that O 2 modulates the photoluminescence of aerogels doped with 4-benzoyl -N -methylpyridinium-based dyads over a wider dynamic range compared wi th aerogels doped with either our vislogen-based dyads or with Ru(I1) tris(1,lO-phenanthroline) itself.

Leventis, Nicholas↗