13,206 research outputs found

    Chemisorption on a model bcc metal

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    The system considered here is that of a single atom with one energy level chemisorbed on the (001) surface of a model bcc metal. We present the change in the density of electronic states Δn (E) due to chemisorption for two cases: one when the adatom is bound to a single substrate atom in the "on‐site" configuration and the other when it is bound to four substrate atoms in the "centered fourfold site." In principle, this change in the density of states Δn can be related to the results of photoemission measurements

    Technique for studying chemisorption on substrates with complex band structures

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    Are regional characteristics of tree growth transmitted through the seed

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    Citation: Cunningham, S. W. Are regional characteristics of tree growth transmitted through the seed. Senior thesis, Kansas State Agricultural College, 1908.Introduction: In the fall of 1896 the Division of Forestry, U.S. Dept. of Agr., invited the department of K.S.A.C. to cooperate in a test of forest-tree seed from various localities. It was the object of these experiments to prove or disprove the prevalent idea that a species may grow successfully over a wide area when propagated from seeds taken within restricted limits

    SPAR data set contents

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    The contents of the stored data sets of the SPAR (space processing applications rocket) finite element structural analysis system are documented. The data generated by each of the system's processors are stored in a data file organized as a library. Each data set, containing a two-dimensional table or matrix, is identified by a four-word name listed in a table of contents. The creating SPAR processor, number of rows and columns, and definitions of each of the data items are listed for each data set. An example SPAR problem using these data sets is also presented

    An investigation of wing buffeting response at subsonic and transonic speeds. Phase 2: F-111A flight data analysis. Volume 1: Summary of technical approach, results and conclusions

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    A detailed investigation of the flight buffeting response of the F-111A was performed in two phases. In Phase 1 stochastic analysis techniques were applied to wing and fuselage responses for maneuvers flown at subsonic speeds and wing leading edge sweep of 26 degrees. Power spectra and rms values were obtained. This report gives results of Phase 2 where the analyses were extended to include maneuvers flown at wing leading edge sweep values of 50 and 75.5 degrees at subsonic and supersonic speeds and the responses examined were expanded to include vertical shear, bending moment, and hingeline torque of the left and right horizontal tails. Power spectra, response time histories, variations of rms response with angle of attack and effects of wing sweep and Mach number are presented and discussed. Some Phase 1 results are given for comparison purposes

    Anomalous optical surface absorption in nominally pure silicon samples at 1550 nm

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    The announcement of the direct detection of Gravitational Waves (GW) by the LIGO and Virgo collaboration in February 2016 has removed any uncertainty around the possibility of GW astronomy. It has demonstrated that future detectors with sensitivities ten times greater than the Advanced LIGO detectors would see thousands of events per year. Many proposals for such future interferometric GW detectors assume the use of silicon test masses. Silicon has low mechanical loss at low temperatures, which leads to low displacement noise for a suspended interferometer mirror. In addition to the low mechanical loss, it is a requirement that the test masses have a low optical loss. Measurements at 1550 nm have indicated that material with a low enough bulk absorption is available; however there have been suggestions that this low absorption material has a surface absorption of > 100 ppm which could preclude its use in future cryogenic detectors. We show in this paper that this surface loss is not intrinsic but is likely to be a result of particular polishing techniques and can be removed or avoided by the correct polishing procedure. This is an important step towards high gravitational wave detection rates in silicon based instruments

    Incorporating regional-scale ecological knowledge to improve the effectiveness of large-scale conservation programmes

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    Land-stewardship programmes are a major focus of investment by governments for conserving biodiversity in agricultural landscapes. These programmes are generally large-scale (e.g. >1000 km) spanning multiple biogeographic regions but developed using spatially limited (e.g. landscape-scale; <100 km) ecological data interpolated across broad areas for one, or a few, well-studied taxonomic groups. Information about how less-studied taxa respond to regional differences in management and environmental effects has potential to further inform land-stewardship conservation programmes, but suitable data sets are rarely available. In this study, we sought to enhance planning of large-scale conservation programmes by quantifying relationships between reptile assemblages and key environmental attributes at regional scales within a large-scale (>172 000 km2) Australian land-stewardship programme. Using 234 remnant woodland monitoring sites spanning four distinct biogeographic regions, we asked: Do reptile assemblages show different environmental associations across biogeographically distinct regions? We found that environmental features important to reptile diversity differed over each region. Abundance and rare species richness of reptiles responded at regional-scales to elevation, native groundcover and aspect. We identified four implications from our study: (1) large-scale conservation schemes can achieve better outcomes for reptiles using regional-scale knowledge of environmental associations; (2) regional-scale knowledge is particularly valuable for conservation of rare reptile taxa; (3) consideration of abiotic environmental features which cannot be directly managed (e.g. aspect, elevation) is important; (4) programmes can be tailored to better support reptile groups at higher conservation risk. Our study shows that reptile-environment associations differ among biogeographic regions, and this presents opportunity for tailoring stronger policy and management strategies for conserving large-scale agricultural landscapes globally. © 2016 The Zoological Society of London. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Philip Barton” is provided in this record*

    Late Time Tail of Wave Propagation on Curved Spacetime

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    The late time behavior of waves propagating on a general curved spacetime is studied. The late time tail is not necessarily an inverse power of time. Our work extends, places in context, and provides understanding for the known results for the Schwarzschild spacetime. Analytic and numerical results are in excellent agreement.Comment: 11 pages, WUGRAV-94-1
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