8,292 research outputs found

    Computational fluid dynamics for propulsion technology: Geometric grid visualization in CFD-based propulsion technology research

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    The coordination is examined of necessary resources, facilities, and special personnel to provide technical integration activities in the area of computational fluid dynamics applied to propulsion technology. Involved is the coordination of CFD activities between government, industry, and universities. Current geometry modeling, grid generation, and graphical methods are established to use in the analysis of CFD design methodologies

    Has Engagement Had Its Day – What’s Next and Does It Matter?

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    Measuring personal growth and development in context: Evidence of validity in educational and work settings

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    Consistent with the trend toward viewing psychological well-being as more than the absence of illness, we developed an instrument – the personal growth and development scale (PGDS) – that can be used to assess positive change in well-being attributable to context-specific experiences. As part of the validation process, we examined relations between the PGDS and measures of need satisfaction and autonomous motivation in students (N = 241) and employees (N = 468). In the student sample, we also examined relations with engagement and burnout. The findings supported our hypothesis that need satisfaction, autonomous motivation and engagement would relate positively with the PGDS, and that burnout would relate negatively. In a second student sample (N = 377), we collected longitudinal data to investigate how global psychological wellbeing relates to personal growth and development over the course of an academic term. We found that initial levels of global well-being predicted positive changes in growth and development – the rich get richer – and replicated earlier findings regarding relations between the PGDS, need satisfaction and autonomous motivation. Future applications of the PGDS for research and practice are discussed

    Impact of single parameter changes on Ceph cloud storage performance

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    In a general purpose cloud system efficiencies are yet to be had from supporting diverse applications and their requirements within a storage system used for a private cloud. Supporting such diverse requirements poses a significant challenge in a storage system that supports fine grained configuration on a variety of parameters. This paper uses the Ceph distributed file system, and in particular its global parameters, to show how a single changed parameter can effect the performance for a range of access patterns when tested with an OpenStack cloud system

    Solar Energy Research Center Instrumentation Facility

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    SOLAR ENERGY RESEARCH CENTER INSTRUMENTATION FACILITY The mission of the Solar Energy Research Center (UNC SERC) at the University of North Carolina at Chapel Hill (UNC-CH) is to establish a world leading effort in solar fuels research and to develop the materials and methods needed to fabricate the next generation of solar energy devices. We are addressing the fundamental issues that will drive new strategies for solar energy conversion and the engineering challenges that must be met in order to convert discoveries made in the laboratory into commercially available devices. The development of a photoelectrosynthesis cell (PEC) for solar fuels production faces daunting requirements: (1) Absorb a large fraction of sunlight; (2) Carry out artificial photosynthesis which involves multiple complex reaction steps; (3) Avoid competitive and deleterious side and reverse reactions; (4) Perform 13 million catalytic cycles per year with minimal degradation; (5) Use non-toxic materials; (6) Cost-effectiveness. PEC efficiency is directly determined by the kinetics of each reaction step. The UNC SERC is addressing this challenge by taking a broad interdisciplinary approach in a highly collaborative setting, drawing on expertise across a broad range of disciplines in chemistry, physics and materials science. By taking a systematic approach toward a fundamental understanding of the mechanism of each step, we will be able to gain unique insight and optimize PEC design. Access to cutting-edge spectroscopic tools is critical to this research effort. We have built professionally-staffed facilities equipped with the state-of the-art instrumentation funded by this award. The combination of staff, facilities, and instrumentation specifically tailored for solar fuels research establishes the UNC Solar Energy Research Center Instrumentation Facility as a unique, world-class capability. This congressionally directed project funded the development of two user facilities: TASK 1: SOLAR DEVICE FABRICATION LABORATORY DEVELOPMENT The space allocated for this laboratory was ñÃÂÃÂshell spaceñÃÂàthat required an upfit in order to accommodate nano-fabrication equipment in a quasi-clean room environment. This construction project (cost 279,736)metthenon−federalcostsharerequirementof279,736) met the non-federal cost share requirement of 250,000 for this award. The central element of the fabrication laboratory is a new $400,000+ stand-alone system, funded by other sources, for fabricating and characterizing photovoltaic devices, in a state-of-the-art nanofabrication environment. This congressionally directed project also included the purchase of an energy dispersive x-ray analysis (EDX) detector for a pre-existing transmission electron microscope (TEM). This detector allows elemental analysis and elemental mapping of materials used to fabricate solar energy devices which is a key priority for our research center. TASK 2: SOLAR ENERGY SPECTROSCOPY LABORATORY DEVELOPMENT (INSTRUMENTATION) This laboratory provides access to modern spectroscopy and photolysis instrumentation for characterizing devices, materials and components on time scales ranging from femtoseconds to seconds and for elucidating mechanisms. The goals of this congressionally directed project included the purchase and installation of spectroscopy and photolysis instrumentation that would substantially and meaningfully enhance the capabilities of this laboratory. Some changes were made to the list of equipment proposed in the original budget. These changes did not represent a change in scope, approach or aims of this project. All of the capabilities and experiments represented in the original budget were maintained. The outcome of this Congressionally Directed Project has been the development of world-class fabrication and spectroscopy user facilities for solar fuels research at UNC-CH. This award has provided a significant augmentation of our pre-existing instrumentation capabilities which were funded by earlier UNC SERC projects, including the Energy Frontier Research Center UNC EFRC, funded by the US Department of Energy Office of Basic Energy Sciences. Equipment funded by this congressional award has provided important new capabilities for UNC SERC and has greatly facilitated collaborative research by many multi-institutional teams in the six partner institutions of the UNC EFRC, including Duke University, North Carolina Central University, and North Carolina State University. This state-of-the-art instrumentation has allowed us to design cutting-edge experiments that provide insight into the molecular structure and dynamics of materials and components for solar energy conversion under real working conditions. This research has resulted in ten publications already published or in preparation that acknowledge support from DOE EERE for this congressionally directed project

    The Nature of the Giant Outbursts in the Bursting Pulsar GRO J 1744-28

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    We investigate the possible role of an accretion disk instability in producing the giant outbursts seen in GRO J1744-28. Specifically, we study the global, time dependent evolution of the Lightman-Eardley instability which can develop near the inner edge of an accretion disk when the radiation pressure becomes comparable to the gas pressure. Broadly speaking, our results are compatible with earlier works by Taam \& Lin and by Lasota \& Pelat. The uniqueness of GRO J1744-28 appears to be associated with the constraint that, in order for outbursts to occur, the rate of accretion at the inner edge must be within a narrow range just above the critical accretion rate at which radiation pressure is beginning to become significant.Comment: 11 pages in .tex file, 4 Postscript figures, .tex file uses aasms.sty; Ap. J. L. 1996, in pres

    Do jumbo-CD holders care about anything?

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    Uninsured deposits represent a theoretically appealing but relatively untested alternative to subordinated debt for incorporating market discipline into banking supervision. To make the deposit market a useful supervisory tool, it is necessary to know what types of risk are priced by depositors and in what proportions. Using a clustering technique to select from among a large set of potential regressors, as well as a carefully chosen set of control variables, we attempt to determine the types of risk that cause uninsured depositors to react in both the price and quantity dimensions. As a benchmark for economic significance, we estimate similar regressions on supervisory ratings. We find that, in contrast to government supervisors, depositors have not priced most types of risk since 1997. Indeed, the only risk variables that consistently come up as statistically significant are those that measure capital adequacy. Our interpretation of these results is that, because aggregate banking conditions are good, it is not worth depositors' effort to investigate individual bank quality very carefully. We conclude that, in the current economic and regulatory environment, the market is content to delegate most of its monitoring and discipline to the government. To the extent that it does monitor, it only monitors capital. The jumbo-CD market is thus not likely to be of much supervisory use, particularly given that examiners already have good information about capital levels. The depositor emphasis on capital also supports the conjecture that market discipline was responsible for much of the recent capital build-up.Bank deposits ; Bank supervision

    Graphical timeline editing

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    NASA's Experiment Scheduling Program (ESP), which has been used for approximately 12 Spacelab missions, is being enhanced with the addition of a Graphical Timeline Editor. The GTE Clipboard, as it is called, was developed to demonstrate new technology which will lead the development of International Space Station Alpha's Payload Planning System and support the remaining Spacelab missions. ESP's GTE Clipboard is developed in C using MIT's X Windows System X11R5 and follows OSF/Motif Style Guide Revision 1.2

    Reassessment of mid-Carboniferous glacial extent in southwestern Gondwana (Rio Blanco Basin, Argentina) inferred from paleo-mass transport of diamictites

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    Late Paleozoic glacial diamictites occur in many localities in western Argentina, indicating that the region was strongly affected by glaciation during the mid-Carboniferous (late Serpukhovian–early Bashkirian). In most instances these diamictites are found in steeply walled paleovalley settings in the Andean Precordillera. This study presents new data from a locality north of the Precordillera that suggests an additional, distinct, volume of ice existed in the region during the Carboniferous. The glacigenic diamictites in the Rio Blanco Basin were ultimately emplaced as gravity flows, precluding inferences of paleo-ice volume. Fold nose orientation and soft-sediment groove orientations within the diamictites indicate that the deposits were emplaced from north to south, suggesting that glacial ice was most likely not sourced from the proto-Precordillera at this locality, requiring the need for another ice center to the north of the basin. Diamictite facies indicates that the sediment was initially supplied to the study area by a warm-based glacier.Fil: Gulbranson, Erik L.. University of California at Davis; Estados Unidos. University of Wisconsin; Estados UnidosFil: Isbell, John L.. University of Wisconsin; Estados UnidosFil: Montañez, Isabel P.. University of California at Davis; Estados UnidosFil: Limarino, Carlos Oscar. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de GeologĂ­a; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; ArgentinaFil: Marenssi, Sergio Alfredo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de GeologĂ­a; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; Argentina. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. DirecciĂłn Nacional del AntĂĄrtico. Instituto AntĂĄrtico Argentino; ArgentinaFil: Meyer, Kyle. University of California at Davis; Estados UnidosFil: Hull, Clara. University of California at Davis; Estados Unido
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